SIMONA CAVALU_Bioactivity evaluation of new silver doped bone cementSimona Cavalu
This document summarizes a study that evaluated the bioactivity and antimicrobial properties of two types of silver-doped bone cement composites. Electrochemical measurements and SEM/FTIR analysis were used to analyze the composites after incubation in simulated body fluid for up to 14 days. The results showed that both composites released silver and calcium ions into the fluid over time. One composite released silver ions more rapidly initially but both developed a hydroxyapatite-like surface layer indicating bioactivity. The layer formed more intensely on the surface of the composite also containing antibiotics. The study demonstrates the antimicrobial activity and bone bonding properties of the silver-doped composites.
SIMONA CAVALU_Comparison between nanostructured aluminosilicate systems with ...Simona Cavalu
The document compares the biocompatibility of aluminosilicate samples containing iron and either dysprosium or yttrium. Scanning electron microscopy images show morphological changes on the sample surfaces after incubation in a collagen solution. Attenuated total reflectance Fourier-transform infrared spectroscopy analysis and deconvolution of the amide I region indicate qualitative and quantitative differences in the secondary structure of adsorbed collagen compared to native collagen. Specifically, collagen adsorbed to the yttrium aluminosilicate sample showed a more pronounced modification of secondary structure, indicating lower biocompatibility. Cyclic voltammetry further supported the quantitative investigations by showing enhanced current intensity and decreased oxidation potential of collagen adsorbed to the electrode surface
This document is an 18 page biology exam for the International General Certificate of Secondary Education. It contains 6 questions testing knowledge of topics including kidney function, antibiotic resistance, the human eye, plant reproduction, digestion, and environmental effects of forest clearing. Students are instructed to answer all questions in the test booklet provided and write their center number, candidate number and name on submitted work. Calculators and diagrams may be used.
SIMONA CAVALU_Microstructure and bioactivity of acrylic bone cementsSimona Cavalu
Polymer-ceramic composites based on polymethyl methacrylate are widely used in orthopaedics as suture materials and
fixation devices due to their biocompatibility and ability to support bony growth (osteoconductive) and also bone bioactive
(to form a calcium phosphate layer on its surface). In this study are compared the microstructure, bioactivity and
biocompatibility of two different types of biocomposites: BIOLOS3®and ANTIBIOTIC SIMPLEX®. They are investigated in
vitro in simulated body fluid using electrochemical measurements, SEM microscopy and ATR-FTIR spectroscopy in order to
evaluate the properties of the surface layer.
This document describes a study on using mid-infrared absorption spectroscopy for label-free detection of phospholipid biomarkers. Phospholipids exhibit strong absorption resonances in the mid-infrared region and are detectable using this technique. The study explores separating phospholipid biomarkers using on-chip capillary electrophoresis in a PDMS microfluidic chip, and then performing label-free detection of the separated biomarkers using mid-infrared absorption spectroscopy by interrogating the biomarkers in the microfluidic channel. Initial experiments detect a phospholipid called phosphatidic acid dissolved in a non-aqueous solvent using this approach, demonstrating the feasibility of the technique for label-free phospholipid sensing.
brief introduction on bone structure and common bone disease, mechanism of targeting, structure and composition of bone delivery system with mentioning some gaps in current research
(1) The document contains a biology exam paper with multiple choice and structured questions testing knowledge of topics like marine animals, plant transport, human genetics, and respiration.
(2) It includes diagrams of experimental setups and pedigrees, as well as requesting explanations, calculations, and analyses of presented information.
(3) The questions cover a wide range of biology concepts and require applying knowledge, making deductions, suggesting explanations, and identifying experimental controls and variables.
This document summarizes the history and discovery of hydrogels. It discusses how Otto and Lim first proposed the use of PHEMA hydrogels in contact lenses in 1960. Lim synthesized some of the first hydrogel materials somewhat by accident in 1954. Since then, hydrogels have found applications in drug delivery, tissue engineering, contact lenses, and other biomedical uses due to their biocompatibility and ability to absorb large amounts of water. The document also discusses stimuli-responsive and "smart" hydrogels that can release drugs in response to environmental triggers like pH, temperature, and electric fields.
SIMONA CAVALU_Bioactivity evaluation of new silver doped bone cementSimona Cavalu
This document summarizes a study that evaluated the bioactivity and antimicrobial properties of two types of silver-doped bone cement composites. Electrochemical measurements and SEM/FTIR analysis were used to analyze the composites after incubation in simulated body fluid for up to 14 days. The results showed that both composites released silver and calcium ions into the fluid over time. One composite released silver ions more rapidly initially but both developed a hydroxyapatite-like surface layer indicating bioactivity. The layer formed more intensely on the surface of the composite also containing antibiotics. The study demonstrates the antimicrobial activity and bone bonding properties of the silver-doped composites.
SIMONA CAVALU_Comparison between nanostructured aluminosilicate systems with ...Simona Cavalu
The document compares the biocompatibility of aluminosilicate samples containing iron and either dysprosium or yttrium. Scanning electron microscopy images show morphological changes on the sample surfaces after incubation in a collagen solution. Attenuated total reflectance Fourier-transform infrared spectroscopy analysis and deconvolution of the amide I region indicate qualitative and quantitative differences in the secondary structure of adsorbed collagen compared to native collagen. Specifically, collagen adsorbed to the yttrium aluminosilicate sample showed a more pronounced modification of secondary structure, indicating lower biocompatibility. Cyclic voltammetry further supported the quantitative investigations by showing enhanced current intensity and decreased oxidation potential of collagen adsorbed to the electrode surface
This document is an 18 page biology exam for the International General Certificate of Secondary Education. It contains 6 questions testing knowledge of topics including kidney function, antibiotic resistance, the human eye, plant reproduction, digestion, and environmental effects of forest clearing. Students are instructed to answer all questions in the test booklet provided and write their center number, candidate number and name on submitted work. Calculators and diagrams may be used.
SIMONA CAVALU_Microstructure and bioactivity of acrylic bone cementsSimona Cavalu
Polymer-ceramic composites based on polymethyl methacrylate are widely used in orthopaedics as suture materials and
fixation devices due to their biocompatibility and ability to support bony growth (osteoconductive) and also bone bioactive
(to form a calcium phosphate layer on its surface). In this study are compared the microstructure, bioactivity and
biocompatibility of two different types of biocomposites: BIOLOS3®and ANTIBIOTIC SIMPLEX®. They are investigated in
vitro in simulated body fluid using electrochemical measurements, SEM microscopy and ATR-FTIR spectroscopy in order to
evaluate the properties of the surface layer.
This document describes a study on using mid-infrared absorption spectroscopy for label-free detection of phospholipid biomarkers. Phospholipids exhibit strong absorption resonances in the mid-infrared region and are detectable using this technique. The study explores separating phospholipid biomarkers using on-chip capillary electrophoresis in a PDMS microfluidic chip, and then performing label-free detection of the separated biomarkers using mid-infrared absorption spectroscopy by interrogating the biomarkers in the microfluidic channel. Initial experiments detect a phospholipid called phosphatidic acid dissolved in a non-aqueous solvent using this approach, demonstrating the feasibility of the technique for label-free phospholipid sensing.
brief introduction on bone structure and common bone disease, mechanism of targeting, structure and composition of bone delivery system with mentioning some gaps in current research
(1) The document contains a biology exam paper with multiple choice and structured questions testing knowledge of topics like marine animals, plant transport, human genetics, and respiration.
(2) It includes diagrams of experimental setups and pedigrees, as well as requesting explanations, calculations, and analyses of presented information.
(3) The questions cover a wide range of biology concepts and require applying knowledge, making deductions, suggesting explanations, and identifying experimental controls and variables.
This document summarizes the history and discovery of hydrogels. It discusses how Otto and Lim first proposed the use of PHEMA hydrogels in contact lenses in 1960. Lim synthesized some of the first hydrogel materials somewhat by accident in 1954. Since then, hydrogels have found applications in drug delivery, tissue engineering, contact lenses, and other biomedical uses due to their biocompatibility and ability to absorb large amounts of water. The document also discusses stimuli-responsive and "smart" hydrogels that can release drugs in response to environmental triggers like pH, temperature, and electric fields.
1) Microfluidic devices handling small liquid volumes can provide cell cultures with an environment mimicking in vivo conditions. This allows studying cell-cell communication and tissue-like structures.
2) Microfluidic devices are fabricated using soft lithography and elastomeric molds like PDMS, as these techniques are compatible with biological applications.
3) Two case studies presented microfluidic devices for depositing two cell types in communicating chambers, and integrating cell culture with on-chip lysis without buffers. These show the potential of microfluidics for advanced cell culture and analysis applications.
This document discusses the application of nanotechnology in biomedical fields such as drug delivery, gene delivery, and tissue engineering. It provides background on the history and definition of nanotechnology. It then discusses various nanomaterials that can be used for targeted drug and gene delivery such as liposomes, polymeric micelles, dendrimers, and nanoparticles. It also describes how microfluidics and nanomaterials can be applied to sperm sorting, oocyte handling, embryo culture, and metabolomics. Overall, the document outlines the current and potential future uses of nanotechnology in biomedicine.
Finite Element Simulation of Microfluidic Biochip for High Throughput Hydrody...TELKOMNIKA JOURNAL
In this paper, a microfluidic device capable of trapping a single cell in a high throughput manner
and at high trapping efficiency is designed simply through a concept of hydrodynamic manipulation. The
microfluidic device is designed with a series of trap and bypass microchannel structures for trapping
individual cells without the need for microwell, robotic equipment, external electric force or surface
modification. In order to investigate the single cell trapping efficiency, a finite element model of the
proposed design has been developed using ABAQUS-FEA software. Based on the simulation, the
geometrical parameters and fluid velocity which affect the single cell trapping are extensively optimized.
After optimization of the trap and bypass microchannel structures via simulations, a single cell can be
trapped at a desired location efficiently.
BIOMINERALISED SILICA-NANOPARTICLES DETECTION FROM MARINE DIATOM CULTURE MEDIAIJSIT Editor
Diatoms are unicellular algae the most spectacular among the microorganisms assemble into a
micro-shell with a distinct 3-D shape and pattern of fine nanoscale features. In this investigation, we present
results; Field Emission Scanning Electron Microscopy images show the presence of ordered arrays of silica
nanoparticles. A number of diatoms with partially opened valves were observed on the surface of the diatom,
which indicates that cell contents inside of diatoms could release the nanoparticles into the culture solution.
We believe that the film forming silica nanoparticles are either released by the diatoms during reproduction
or after cell death due to bacterial action. Further research will investigate whether the silica nanoparticles
are produced intracellular and then released or whether synthesis occurs in cell culture medium. This
approach provides an environmentally friendly means for fabricating silica nanoparticles for drug delivery,
disease diagnostics, artificial opal films, decorative coatings and novel optical materials.
1) The study aims to engineer an in-vitro dentin-pulp interface construct using micropatterned porous membranes to mimic the organized layer of odontoblast cells.
2) A two-step lithography and deep reactive ion etching process was used to create patterned silicon molds, which were then used to create polycaprolactone membranes with pillar and pore structures mimicking dentin tubules.
3) Initial tests show the pillar structures restricted cell spreading on the membranes as desired, and a chemical gradient induced cell process formation through the pores, demonstrating the potential to guide cell polarization in 3D.
The authors developed a multi-material scaffold fabrication process using photopolymerization. They studied how manufacturing parameters affected tissue construct formation. Scaffolds were created in three layers using polyethylene glycol diacrylate and photoinitiators. A dissolvable plastic Y-shape was 3D printed to form the internal architecture, then additional layers were added. The scaffolds had precise branching channels and were biocompatible materials that supported cell growth.
This document discusses using 3D imaging techniques to study bacterial biofilms. It describes culturing a Staphylococcus aureus biofilm on a polystyrene petri dish as a control. A focused ion beam scanning electron microscope is used to take serial images of the biofilm, which are reconstructed into a 3D model using Avizo Fire software. This provides quantitative data on how the biofilm grows and its structure. Future work aims to study how biofilm structure changes with different material surfaces, informing medical device design to prevent infections.
IJCER (www.ijceronline.com) International Journal of computational Engineerin...ijceronline
This document summarizes research on the preparation and characterization of natural degradable microcapsules. The researchers used a layer-by-layer technique to assemble alternating layers of chitosan and dextran sulfate on silica template particles. They then removed the silica core using hydrofluoric acid to produce hollow microcapsules. Scanning electron microscopy and energy dispersive X-ray analysis showed the microcapsules were pure and intact, with a thickness of around 350 nm. The biodegradable microcapsules produced using this technique could have applications for drug encapsulation and controlled release in the pharmaceutical industry.
A Tale of Two Processes: Simulation vs ExperimentationKathleen Broughton
This document summarizes a student's course project involving microfluidic micromixers. The student designed a micromixer using simulation software, fabricated a physical micromixer, and tested it experimentally. Key findings include:
1) Simulation experiments found that a simple trapezoidal zigzag design produced nearly perfect mixing. Testing different parameters like channel width and inlet profiles showed their impact on mixing.
2) Fabricating the physical micromixer using photolithography was successful. Measurements showed the channel heights were close to the designed 50 microns.
3) Experimental testing at different flow rates found consistent fluorescent intensity across the outlet. Comparing normalized experimental and simulation data showed good agreement except at the
This document describes an experiment aiming to develop a 3D cancer cell culture model that more closely mimics in vivo tumor growth conditions. Key aspects of the model include: 1) Controlling oxygenation using a bioreactor with an oxygen gradient from hypoxic to anoxic conditions; 2) Fabricating micropillars to act as synthetic vessels for cell spheroids to grow around; 3) Embedding cells in extracellular matrix to allow cell-cell and cell-ECM interactions. The experiment involves growing cancer cells for 7 days under various oxygen conditions and analyzing differences in gene expression and spheroid growth.
Microsphere scaffolds are used for controlled drug delivery and tissue engineering. Microspheres are spherical polymer particles that can encapsulate drugs or growth factors. Microsphere scaffolds provide controlled release of encapsulated molecules and serve as 3D structures to support tissue regeneration. Microspheres can be fabricated into scaffolds by dispersing them in a polymer matrix or fusing them together. These microsphere-based scaffolds allow customization of drug release and mechanical properties. They have applications in regenerating tissues like cartilage, skin, heart and liver.
This document describes research into developing a new green resist material for microfabrication processes using animal-derived biopolymers. Bovine serum albumin (BSA) and fish gelatin were tested as potential water-based resists. BSA films of 5-10% concentration were successfully spin coated on silicon and silica wafers, with thicker films produced at lower spin speeds. Ellipsometry measurements determined film thicknesses ranging from 70-270 nm for BSA and 6-15 nm for 1.5% fish gelatin. Exposure to plasma etching showed BSA films were etched at rates of 4-16 nm/min, with thicker BSA films unexpectedly etching faster. While BSA showed potential as
This document summarizes research on creating honeycomb nanofibrous membranes for bone regeneration using micro-weaving. Honeycomb collectors with pattern diameters of 40-360 microns were created and used to generate honeycomb scaffolds of PCL and PLA nanofibers. The PCL scaffolds had thicker fibers along the walls and a bimodal fiber diameter distribution, while the PLA scaffolds had uniformly thin fibers and high fiber alignment. The scaffolds differed in roughness and shrinkage. In vitro studies will evaluate how the honeycomb organization influences osteoblast proliferation and morphology to determine the best polymer for structured scaffolds in bone regeneration.
wo-photon polymerization has recently emerged as a promising technique to fabricate scaffolds for three-dimensional (3D) cell culture and tissue engineering. Here, we combined 3D-printed microscale scaffolds fabricated using two-photon polymerization with a bioactive layer-by-layer film coating. This bioactive coating consists of hyaluronic acid and poly(l-lysine) of controlled stiffness, loaded with fibronectin and bone morphogenic proteins 2 and 4 (BMP2 and BMP4) as matrix-bound proteins. Planar films were prepared using a liquid handling robot directly in 96-well plates to perform high-content studies of cellular processes, especially cell adhesion, proliferation, and BMP-induced signaling. The behaviors of two human pancreatic cell lines PANC1 (immortalized) and PAN092 (patient-derived cell line) were systematically compared and revealed important context-specific cell responses, notably in response to film stiffness and matrix-bound BMPs (bBMPs). Fibronectin significantly increased cell adhesion, spreading, and proliferation for both cell types on soft and stiff films; BMP2 increased cell adhesion and inhibited proliferation of PANC1 cells and PAN092 on soft films. BMP4 enhanced cell adhesion and proliferation of PANC1 and showed a bipolar effect on PAN092. Importantly, PANC1 exhibited a strong dose-dependent BMP response, notably for bBMP2, while PAN092 was insensitive to BMPs. Finally, we proved that it is possible to combine a microscale 3D Ormocomp scaffold fabricated using the two-photon polymerization technique with the bioactive film coating to form a microscale tumor tissue and mimic the early stages of metastatic cancer.
This document discusses bio-inspired approaches for creating complex superstructures. It begins by introducing bio-inspired design and how biological materials exhibit multifunctional integration at multiple scales. Examples are given of specific biological materials like lotus leaves, rice leaves, butterfly wings, spider silks, and moth eyes that inspire structures for properties like superhydrophobicity, iridescence, mechanical strength, and anti-reflectiveness. The document then covers typical materials and approaches used to create bio-inspired superstructures, such as self-assembly techniques and composite materials. It concludes by noting opportunities to further understand and apply multiscale design principles from nature.
Cellulose has a hierarchical structure, with cotton fibers made of macrofibrils containing microfibrils and nanocellulose fibrils. Microfibrils are crystalline sheets composed of cellulose macromolecules made of repeating cellobiose units linked by glycosidic bonds. These crystalline sheets stack parallel to each other in microfibrils, forming a highly ordered structure that is exceptionally stiff and strong.
This document discusses the techniques of correlated cryo-light microscopy (CLM) and soft X-ray tomography (SXT) for visualizing cell architecture and molecular location. CLM provides high-resolution fluorescent imaging of cells at cryogenic temperatures to localize molecules, while SXT uses soft X-rays to visualize internal cell structure. The two techniques are performed sequentially on the same sample and the data is merged to provide a composite 3D view of both cell structure and molecular location within cells. Specimen preparation, 3D reconstruction, alignment using fiducial markers, and segmentation based on linear absorption coefficients are discussed.
This document describes a method for fabricating porous poly(DL-lactic-co-glycolic acid) (PLGA) microspheres that fuse together at body temperature to form solid porous scaffolds, creating an injectable scaffold system. The microspheres were treated with ethanolic sodium hydroxide to increase surface porosity without disintegrating. When mixed with media and incubated at 37°C, the microspheres fused to form scaffolds with compressive strength of 0.9 MPa, porosity of 81.6%, and pore diameter of 54 μm, supporting NIH-3T3 cell attachment and proliferation in vitro. This study demonstrates a technique for producing an injectable and porous PLGA scaffold that solid
Launching digital biology, 12 May 2015, Bremenbioflux
Intro. It is not a secret that in biology laboratories hours of manual work are considered a compulsory part of the experiment. During a day of work, lab researchers have to pipette the right amounts of fluids in tubes, carry them from one machine to another, program and handle each machine individually, label and document carefully each step and then convert the results to data and analyse it. For a simple routine experiment, each of the mentioned tasks is performed at least 10 times/day. Past decade, a big effort has been done to produce machines (e.g., pipetting robots) that would automate some of the tasks in the lab. However, these machines were developed under the industrial mindset to maximize the throughput of a single task. Thus, these machines are of large size, task-specific, difficult to use (they usually come with dedicated drivers and software) and most importantly, extremely expensive. A solution is the use of digital microfluidics to enable the advance from automated biology to digital biology. In my vision, a digital lab should be:
• fully integrated, running all the tasks on the same machine
• easy to use, with a web-based software for biological design of new experiments and hardware control
• general-purpose, allowing easy reconfiguration and design of new experiments
• cheap, offering open-source and do-it-yourself assembly kits
Talk. In the talk, I will present an overview of the road to digital biology, covering all the main aspects, from computer-aided design to hardware production and biological applications.
Hands on. Also, prepare for some real engineering action :). I will execute live a biochemical application (enzymatic reaction of β-galactosidase with Xgal) on my homemade digital biochip. We will then discuss the current challenges in the development process and everyone will get a chance to play with the device. And of course, I will happily consider any engineering advice or idea you have :).
Создан первый в мире мягкий автономный роботAnatol Alizar
The document summarizes research on the development of an entirely soft, autonomous robot ("octobot") composed solely of soft materials. Key points:
- Researchers developed a method to fabricate a soft robot using microfluidic logic as a soft controller and a multi-material 3D printing technique to pattern pneumatic networks and other components within an elastomeric body.
- The soft controller regulates fluid flow from onboard monopropellant fuel reservoirs to catalytic reaction chambers, generating gas to inflate actuators for movement.
- The integrated design and rapid fabrication approach allows multiple materials like elastomers and inks to be seamlessly incorporated, enabling fully soft, programmable and untethered robotic function.
Brief report on disinfection using uv radiation by incubig korea and pan iitDr. Sitansu Sekhar Nanda
December 31 last year, China alerted WHO to several cases of people being affected by an
unknown “Virus”. The new disease was called COVID-19 and the virus causing it was identified as
SARS_CoV2/ COVID-19 virus, a member of the Coronavirus family, which includes SARS, MERS and
the common cold.
Controlling and manipulating matter on the nanometer-length scale (1-100 nm), and
Exploiting novel phenomena and properties (physical, chemical, biological, mechanical, electrical) at the nanoscale.
More Related Content
Similar to Microfluidic formation of cell laden hydrogel modules for tissue engineering
1) Microfluidic devices handling small liquid volumes can provide cell cultures with an environment mimicking in vivo conditions. This allows studying cell-cell communication and tissue-like structures.
2) Microfluidic devices are fabricated using soft lithography and elastomeric molds like PDMS, as these techniques are compatible with biological applications.
3) Two case studies presented microfluidic devices for depositing two cell types in communicating chambers, and integrating cell culture with on-chip lysis without buffers. These show the potential of microfluidics for advanced cell culture and analysis applications.
This document discusses the application of nanotechnology in biomedical fields such as drug delivery, gene delivery, and tissue engineering. It provides background on the history and definition of nanotechnology. It then discusses various nanomaterials that can be used for targeted drug and gene delivery such as liposomes, polymeric micelles, dendrimers, and nanoparticles. It also describes how microfluidics and nanomaterials can be applied to sperm sorting, oocyte handling, embryo culture, and metabolomics. Overall, the document outlines the current and potential future uses of nanotechnology in biomedicine.
Finite Element Simulation of Microfluidic Biochip for High Throughput Hydrody...TELKOMNIKA JOURNAL
In this paper, a microfluidic device capable of trapping a single cell in a high throughput manner
and at high trapping efficiency is designed simply through a concept of hydrodynamic manipulation. The
microfluidic device is designed with a series of trap and bypass microchannel structures for trapping
individual cells without the need for microwell, robotic equipment, external electric force or surface
modification. In order to investigate the single cell trapping efficiency, a finite element model of the
proposed design has been developed using ABAQUS-FEA software. Based on the simulation, the
geometrical parameters and fluid velocity which affect the single cell trapping are extensively optimized.
After optimization of the trap and bypass microchannel structures via simulations, a single cell can be
trapped at a desired location efficiently.
BIOMINERALISED SILICA-NANOPARTICLES DETECTION FROM MARINE DIATOM CULTURE MEDIAIJSIT Editor
Diatoms are unicellular algae the most spectacular among the microorganisms assemble into a
micro-shell with a distinct 3-D shape and pattern of fine nanoscale features. In this investigation, we present
results; Field Emission Scanning Electron Microscopy images show the presence of ordered arrays of silica
nanoparticles. A number of diatoms with partially opened valves were observed on the surface of the diatom,
which indicates that cell contents inside of diatoms could release the nanoparticles into the culture solution.
We believe that the film forming silica nanoparticles are either released by the diatoms during reproduction
or after cell death due to bacterial action. Further research will investigate whether the silica nanoparticles
are produced intracellular and then released or whether synthesis occurs in cell culture medium. This
approach provides an environmentally friendly means for fabricating silica nanoparticles for drug delivery,
disease diagnostics, artificial opal films, decorative coatings and novel optical materials.
1) The study aims to engineer an in-vitro dentin-pulp interface construct using micropatterned porous membranes to mimic the organized layer of odontoblast cells.
2) A two-step lithography and deep reactive ion etching process was used to create patterned silicon molds, which were then used to create polycaprolactone membranes with pillar and pore structures mimicking dentin tubules.
3) Initial tests show the pillar structures restricted cell spreading on the membranes as desired, and a chemical gradient induced cell process formation through the pores, demonstrating the potential to guide cell polarization in 3D.
The authors developed a multi-material scaffold fabrication process using photopolymerization. They studied how manufacturing parameters affected tissue construct formation. Scaffolds were created in three layers using polyethylene glycol diacrylate and photoinitiators. A dissolvable plastic Y-shape was 3D printed to form the internal architecture, then additional layers were added. The scaffolds had precise branching channels and were biocompatible materials that supported cell growth.
This document discusses using 3D imaging techniques to study bacterial biofilms. It describes culturing a Staphylococcus aureus biofilm on a polystyrene petri dish as a control. A focused ion beam scanning electron microscope is used to take serial images of the biofilm, which are reconstructed into a 3D model using Avizo Fire software. This provides quantitative data on how the biofilm grows and its structure. Future work aims to study how biofilm structure changes with different material surfaces, informing medical device design to prevent infections.
IJCER (www.ijceronline.com) International Journal of computational Engineerin...ijceronline
This document summarizes research on the preparation and characterization of natural degradable microcapsules. The researchers used a layer-by-layer technique to assemble alternating layers of chitosan and dextran sulfate on silica template particles. They then removed the silica core using hydrofluoric acid to produce hollow microcapsules. Scanning electron microscopy and energy dispersive X-ray analysis showed the microcapsules were pure and intact, with a thickness of around 350 nm. The biodegradable microcapsules produced using this technique could have applications for drug encapsulation and controlled release in the pharmaceutical industry.
A Tale of Two Processes: Simulation vs ExperimentationKathleen Broughton
This document summarizes a student's course project involving microfluidic micromixers. The student designed a micromixer using simulation software, fabricated a physical micromixer, and tested it experimentally. Key findings include:
1) Simulation experiments found that a simple trapezoidal zigzag design produced nearly perfect mixing. Testing different parameters like channel width and inlet profiles showed their impact on mixing.
2) Fabricating the physical micromixer using photolithography was successful. Measurements showed the channel heights were close to the designed 50 microns.
3) Experimental testing at different flow rates found consistent fluorescent intensity across the outlet. Comparing normalized experimental and simulation data showed good agreement except at the
This document describes an experiment aiming to develop a 3D cancer cell culture model that more closely mimics in vivo tumor growth conditions. Key aspects of the model include: 1) Controlling oxygenation using a bioreactor with an oxygen gradient from hypoxic to anoxic conditions; 2) Fabricating micropillars to act as synthetic vessels for cell spheroids to grow around; 3) Embedding cells in extracellular matrix to allow cell-cell and cell-ECM interactions. The experiment involves growing cancer cells for 7 days under various oxygen conditions and analyzing differences in gene expression and spheroid growth.
Microsphere scaffolds are used for controlled drug delivery and tissue engineering. Microspheres are spherical polymer particles that can encapsulate drugs or growth factors. Microsphere scaffolds provide controlled release of encapsulated molecules and serve as 3D structures to support tissue regeneration. Microspheres can be fabricated into scaffolds by dispersing them in a polymer matrix or fusing them together. These microsphere-based scaffolds allow customization of drug release and mechanical properties. They have applications in regenerating tissues like cartilage, skin, heart and liver.
This document describes research into developing a new green resist material for microfabrication processes using animal-derived biopolymers. Bovine serum albumin (BSA) and fish gelatin were tested as potential water-based resists. BSA films of 5-10% concentration were successfully spin coated on silicon and silica wafers, with thicker films produced at lower spin speeds. Ellipsometry measurements determined film thicknesses ranging from 70-270 nm for BSA and 6-15 nm for 1.5% fish gelatin. Exposure to plasma etching showed BSA films were etched at rates of 4-16 nm/min, with thicker BSA films unexpectedly etching faster. While BSA showed potential as
This document summarizes research on creating honeycomb nanofibrous membranes for bone regeneration using micro-weaving. Honeycomb collectors with pattern diameters of 40-360 microns were created and used to generate honeycomb scaffolds of PCL and PLA nanofibers. The PCL scaffolds had thicker fibers along the walls and a bimodal fiber diameter distribution, while the PLA scaffolds had uniformly thin fibers and high fiber alignment. The scaffolds differed in roughness and shrinkage. In vitro studies will evaluate how the honeycomb organization influences osteoblast proliferation and morphology to determine the best polymer for structured scaffolds in bone regeneration.
wo-photon polymerization has recently emerged as a promising technique to fabricate scaffolds for three-dimensional (3D) cell culture and tissue engineering. Here, we combined 3D-printed microscale scaffolds fabricated using two-photon polymerization with a bioactive layer-by-layer film coating. This bioactive coating consists of hyaluronic acid and poly(l-lysine) of controlled stiffness, loaded with fibronectin and bone morphogenic proteins 2 and 4 (BMP2 and BMP4) as matrix-bound proteins. Planar films were prepared using a liquid handling robot directly in 96-well plates to perform high-content studies of cellular processes, especially cell adhesion, proliferation, and BMP-induced signaling. The behaviors of two human pancreatic cell lines PANC1 (immortalized) and PAN092 (patient-derived cell line) were systematically compared and revealed important context-specific cell responses, notably in response to film stiffness and matrix-bound BMPs (bBMPs). Fibronectin significantly increased cell adhesion, spreading, and proliferation for both cell types on soft and stiff films; BMP2 increased cell adhesion and inhibited proliferation of PANC1 cells and PAN092 on soft films. BMP4 enhanced cell adhesion and proliferation of PANC1 and showed a bipolar effect on PAN092. Importantly, PANC1 exhibited a strong dose-dependent BMP response, notably for bBMP2, while PAN092 was insensitive to BMPs. Finally, we proved that it is possible to combine a microscale 3D Ormocomp scaffold fabricated using the two-photon polymerization technique with the bioactive film coating to form a microscale tumor tissue and mimic the early stages of metastatic cancer.
This document discusses bio-inspired approaches for creating complex superstructures. It begins by introducing bio-inspired design and how biological materials exhibit multifunctional integration at multiple scales. Examples are given of specific biological materials like lotus leaves, rice leaves, butterfly wings, spider silks, and moth eyes that inspire structures for properties like superhydrophobicity, iridescence, mechanical strength, and anti-reflectiveness. The document then covers typical materials and approaches used to create bio-inspired superstructures, such as self-assembly techniques and composite materials. It concludes by noting opportunities to further understand and apply multiscale design principles from nature.
Cellulose has a hierarchical structure, with cotton fibers made of macrofibrils containing microfibrils and nanocellulose fibrils. Microfibrils are crystalline sheets composed of cellulose macromolecules made of repeating cellobiose units linked by glycosidic bonds. These crystalline sheets stack parallel to each other in microfibrils, forming a highly ordered structure that is exceptionally stiff and strong.
This document discusses the techniques of correlated cryo-light microscopy (CLM) and soft X-ray tomography (SXT) for visualizing cell architecture and molecular location. CLM provides high-resolution fluorescent imaging of cells at cryogenic temperatures to localize molecules, while SXT uses soft X-rays to visualize internal cell structure. The two techniques are performed sequentially on the same sample and the data is merged to provide a composite 3D view of both cell structure and molecular location within cells. Specimen preparation, 3D reconstruction, alignment using fiducial markers, and segmentation based on linear absorption coefficients are discussed.
This document describes a method for fabricating porous poly(DL-lactic-co-glycolic acid) (PLGA) microspheres that fuse together at body temperature to form solid porous scaffolds, creating an injectable scaffold system. The microspheres were treated with ethanolic sodium hydroxide to increase surface porosity without disintegrating. When mixed with media and incubated at 37°C, the microspheres fused to form scaffolds with compressive strength of 0.9 MPa, porosity of 81.6%, and pore diameter of 54 μm, supporting NIH-3T3 cell attachment and proliferation in vitro. This study demonstrates a technique for producing an injectable and porous PLGA scaffold that solid
Launching digital biology, 12 May 2015, Bremenbioflux
Intro. It is not a secret that in biology laboratories hours of manual work are considered a compulsory part of the experiment. During a day of work, lab researchers have to pipette the right amounts of fluids in tubes, carry them from one machine to another, program and handle each machine individually, label and document carefully each step and then convert the results to data and analyse it. For a simple routine experiment, each of the mentioned tasks is performed at least 10 times/day. Past decade, a big effort has been done to produce machines (e.g., pipetting robots) that would automate some of the tasks in the lab. However, these machines were developed under the industrial mindset to maximize the throughput of a single task. Thus, these machines are of large size, task-specific, difficult to use (they usually come with dedicated drivers and software) and most importantly, extremely expensive. A solution is the use of digital microfluidics to enable the advance from automated biology to digital biology. In my vision, a digital lab should be:
• fully integrated, running all the tasks on the same machine
• easy to use, with a web-based software for biological design of new experiments and hardware control
• general-purpose, allowing easy reconfiguration and design of new experiments
• cheap, offering open-source and do-it-yourself assembly kits
Talk. In the talk, I will present an overview of the road to digital biology, covering all the main aspects, from computer-aided design to hardware production and biological applications.
Hands on. Also, prepare for some real engineering action :). I will execute live a biochemical application (enzymatic reaction of β-galactosidase with Xgal) on my homemade digital biochip. We will then discuss the current challenges in the development process and everyone will get a chance to play with the device. And of course, I will happily consider any engineering advice or idea you have :).
Создан первый в мире мягкий автономный роботAnatol Alizar
The document summarizes research on the development of an entirely soft, autonomous robot ("octobot") composed solely of soft materials. Key points:
- Researchers developed a method to fabricate a soft robot using microfluidic logic as a soft controller and a multi-material 3D printing technique to pattern pneumatic networks and other components within an elastomeric body.
- The soft controller regulates fluid flow from onboard monopropellant fuel reservoirs to catalytic reaction chambers, generating gas to inflate actuators for movement.
- The integrated design and rapid fabrication approach allows multiple materials like elastomers and inks to be seamlessly incorporated, enabling fully soft, programmable and untethered robotic function.
Similar to Microfluidic formation of cell laden hydrogel modules for tissue engineering (20)
Brief report on disinfection using uv radiation by incubig korea and pan iitDr. Sitansu Sekhar Nanda
December 31 last year, China alerted WHO to several cases of people being affected by an
unknown “Virus”. The new disease was called COVID-19 and the virus causing it was identified as
SARS_CoV2/ COVID-19 virus, a member of the Coronavirus family, which includes SARS, MERS and
the common cold.
Controlling and manipulating matter on the nanometer-length scale (1-100 nm), and
Exploiting novel phenomena and properties (physical, chemical, biological, mechanical, electrical) at the nanoscale.
Since the Nobel prize for Physics was awarded to Andre Geim and Konstantin Novoselov “for groundbreaking experiments regarding the two-dimensional material graphene”, the eyes of the scientific world have been focused on this so-called miracle material.
This document contains 22 figures showing transmission electron microscopy (TEM) images and scanning electron microscopy (SEM) images of various nanomaterials, including CdSe nanocrystals, CdS nanowires, ZnO nanostructures, FeO(OH) and Fe2O3 nanostructures, silicon nanowire arrays, Ni-Cu nanowires, nanoparticle-supported composite structures, and biofunctionalized nanoparticles. The nanomaterials were synthesized using methods such as hydrothermal processing, thermal annealing, and ligand-assisted assembly. The images characterize the shapes, sizes, and arrangements of the nanostructures produced.
Stem cells and nanotechnology in regenerative medicine and tissue engineeringDr. Sitansu Sekhar Nanda
Alexis Carrel, winner of the Nobel Prize in Physiology or Medicine in 1912 and the father of whole-organ transplant, was the first to develop a successful technique for end to end arteriovenous anastomosis in transplantation.
Micro and nanoengineering approaches to developing gradient biomaterials sui...Dr. Sitansu Sekhar Nanda
This document discusses approaches for developing gradient biomaterials suitable for interface tissue engineering. It explains that gradient biomaterials can regulate cell behavior during tissue formation at interfaces between soft and hard tissues. The document then describes various types of gradient biomaterials, including those involving material composition, structure, physical properties, and biological factors. It also outlines several micro and nanoengineering techniques that can be used to fabricate gradient biomaterials, such as salt leaching, gas foaming, photolithography, and electrospinning.
Characterization of the adhesive interactions between cells and biomaterialsDr. Sitansu Sekhar Nanda
This document discusses characterization of adhesive interactions between cells and biomaterials. It begins by introducing how biomaterials are used to facilitate cell adhesion during tissue repair or replacement. It then discusses various adhesion receptors in native tissue like integrins, their classification and role in connecting the extracellular and intracellular environments. The document also covers optimization of cellular adhesion through biomaterial modification and different methods to measure cell adhesion like micromanipulation, centrifugation and applying hydrodynamic shear stress. It concludes that modifying biomaterials to mimic native adhesive interactions can help control downstream cell responses and have therapeutic applications.
HCL Notes and Domino License Cost Reduction in the World of DLAUpanagenda
Webinar Recording: https://www.panagenda.com/webinars/hcl-notes-and-domino-license-cost-reduction-in-the-world-of-dlau/
The introduction of DLAU and the CCB & CCX licensing model caused quite a stir in the HCL community. As a Notes and Domino customer, you may have faced challenges with unexpected user counts and license costs. You probably have questions on how this new licensing approach works and how to benefit from it. Most importantly, you likely have budget constraints and want to save money where possible. Don’t worry, we can help with all of this!
We’ll show you how to fix common misconfigurations that cause higher-than-expected user counts, and how to identify accounts which you can deactivate to save money. There are also frequent patterns that can cause unnecessary cost, like using a person document instead of a mail-in for shared mailboxes. We’ll provide examples and solutions for those as well. And naturally we’ll explain the new licensing model.
Join HCL Ambassador Marc Thomas in this webinar with a special guest appearance from Franz Walder. It will give you the tools and know-how to stay on top of what is going on with Domino licensing. You will be able lower your cost through an optimized configuration and keep it low going forward.
These topics will be covered
- Reducing license cost by finding and fixing misconfigurations and superfluous accounts
- How do CCB and CCX licenses really work?
- Understanding the DLAU tool and how to best utilize it
- Tips for common problem areas, like team mailboxes, functional/test users, etc
- Practical examples and best practices to implement right away
GraphRAG for Life Science to increase LLM accuracyTomaz Bratanic
GraphRAG for life science domain, where you retriever information from biomedical knowledge graphs using LLMs to increase the accuracy and performance of generated answers
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/06/building-and-scaling-ai-applications-with-the-nx-ai-manager-a-presentation-from-network-optix/
Robin van Emden, Senior Director of Data Science at Network Optix, presents the “Building and Scaling AI Applications with the Nx AI Manager,” tutorial at the May 2024 Embedded Vision Summit.
In this presentation, van Emden covers the basics of scaling edge AI solutions using the Nx tool kit. He emphasizes the process of developing AI models and deploying them globally. He also showcases the conversion of AI models and the creation of effective edge AI pipelines, with a focus on pre-processing, model conversion, selecting the appropriate inference engine for the target hardware and post-processing.
van Emden shows how Nx can simplify the developer’s life and facilitate a rapid transition from concept to production-ready applications.He provides valuable insights into developing scalable and efficient edge AI solutions, with a strong focus on practical implementation.
How to Get CNIC Information System with Paksim Ga.pptxdanishmna97
Pakdata Cf is a groundbreaking system designed to streamline and facilitate access to CNIC information. This innovative platform leverages advanced technology to provide users with efficient and secure access to their CNIC details.
Dr. Sean Tan, Head of Data Science, Changi Airport Group
Discover how Changi Airport Group (CAG) leverages graph technologies and generative AI to revolutionize their search capabilities. This session delves into the unique search needs of CAG’s diverse passengers and customers, showcasing how graph data structures enhance the accuracy and relevance of AI-generated search results, mitigating the risk of “hallucinations” and improving the overall customer journey.
Driving Business Innovation: Latest Generative AI Advancements & Success StorySafe Software
Are you ready to revolutionize how you handle data? Join us for a webinar where we’ll bring you up to speed with the latest advancements in Generative AI technology and discover how leveraging FME with tools from giants like Google Gemini, Amazon, and Microsoft OpenAI can supercharge your workflow efficiency.
During the hour, we’ll take you through:
Guest Speaker Segment with Hannah Barrington: Dive into the world of dynamic real estate marketing with Hannah, the Marketing Manager at Workspace Group. Hear firsthand how their team generates engaging descriptions for thousands of office units by integrating diverse data sources—from PDF floorplans to web pages—using FME transformers, like OpenAIVisionConnector and AnthropicVisionConnector. This use case will show you how GenAI can streamline content creation for marketing across the board.
Ollama Use Case: Learn how Scenario Specialist Dmitri Bagh has utilized Ollama within FME to input data, create custom models, and enhance security protocols. This segment will include demos to illustrate the full capabilities of FME in AI-driven processes.
Custom AI Models: Discover how to leverage FME to build personalized AI models using your data. Whether it’s populating a model with local data for added security or integrating public AI tools, find out how FME facilitates a versatile and secure approach to AI.
We’ll wrap up with a live Q&A session where you can engage with our experts on your specific use cases, and learn more about optimizing your data workflows with AI.
This webinar is ideal for professionals seeking to harness the power of AI within their data management systems while ensuring high levels of customization and security. Whether you're a novice or an expert, gain actionable insights and strategies to elevate your data processes. Join us to see how FME and AI can revolutionize how you work with data!
Essentials of Automations: The Art of Triggers and Actions in FMESafe Software
In this second installment of our Essentials of Automations webinar series, we’ll explore the landscape of triggers and actions, guiding you through the nuances of authoring and adapting workspaces for seamless automations. Gain an understanding of the full spectrum of triggers and actions available in FME, empowering you to enhance your workspaces for efficient automation.
We’ll kick things off by showcasing the most commonly used event-based triggers, introducing you to various automation workflows like manual triggers, schedules, directory watchers, and more. Plus, see how these elements play out in real scenarios.
Whether you’re tweaking your current setup or building from the ground up, this session will arm you with the tools and insights needed to transform your FME usage into a powerhouse of productivity. Join us to discover effective strategies that simplify complex processes, enhancing your productivity and transforming your data management practices with FME. Let’s turn complexity into clarity and make your workspaces work wonders!
TrustArc Webinar - 2024 Global Privacy SurveyTrustArc
How does your privacy program stack up against your peers? What challenges are privacy teams tackling and prioritizing in 2024?
In the fifth annual Global Privacy Benchmarks Survey, we asked over 1,800 global privacy professionals and business executives to share their perspectives on the current state of privacy inside and outside of their organizations. This year’s report focused on emerging areas of importance for privacy and compliance professionals, including considerations and implications of Artificial Intelligence (AI) technologies, building brand trust, and different approaches for achieving higher privacy competence scores.
See how organizational priorities and strategic approaches to data security and privacy are evolving around the globe.
This webinar will review:
- The top 10 privacy insights from the fifth annual Global Privacy Benchmarks Survey
- The top challenges for privacy leaders, practitioners, and organizations in 2024
- Key themes to consider in developing and maintaining your privacy program
GraphSummit Singapore | The Future of Agility: Supercharging Digital Transfor...Neo4j
Leonard Jayamohan, Partner & Generative AI Lead, Deloitte
This keynote will reveal how Deloitte leverages Neo4j’s graph power for groundbreaking digital twin solutions, achieving a staggering 100x performance boost. Discover the essential role knowledge graphs play in successful generative AI implementations. Plus, get an exclusive look at an innovative Neo4j + Generative AI solution Deloitte is developing in-house.
Unlocking Productivity: Leveraging the Potential of Copilot in Microsoft 365, a presentation by Christoforos Vlachos, Senior Solutions Manager – Modern Workplace, Uni Systems
In his public lecture, Christian Timmerer provides insights into the fascinating history of video streaming, starting from its humble beginnings before YouTube to the groundbreaking technologies that now dominate platforms like Netflix and ORF ON. Timmerer also presents provocative contributions of his own that have significantly influenced the industry. He concludes by looking at future challenges and invites the audience to join in a discussion.
Programming Foundation Models with DSPy - Meetup SlidesZilliz
Prompting language models is hard, while programming language models is easy. In this talk, I will discuss the state-of-the-art framework DSPy for programming foundation models with its powerful optimizers and runtime constraint system.
Full-RAG: A modern architecture for hyper-personalizationZilliz
Mike Del Balso, CEO & Co-Founder at Tecton, presents "Full RAG," a novel approach to AI recommendation systems, aiming to push beyond the limitations of traditional models through a deep integration of contextual insights and real-time data, leveraging the Retrieval-Augmented Generation architecture. This talk will outline Full RAG's potential to significantly enhance personalization, address engineering challenges such as data management and model training, and introduce data enrichment with reranking as a key solution. Attendees will gain crucial insights into the importance of hyperpersonalization in AI, the capabilities of Full RAG for advanced personalization, and strategies for managing complex data integrations for deploying cutting-edge AI solutions.
AI 101: An Introduction to the Basics and Impact of Artificial IntelligenceIndexBug
Imagine a world where machines not only perform tasks but also learn, adapt, and make decisions. This is the promise of Artificial Intelligence (AI), a technology that's not just enhancing our lives but revolutionizing entire industries.
AI 101: An Introduction to the Basics and Impact of Artificial Intelligence
Microfluidic formation of cell laden hydrogel modules for tissue engineering
1. MICROFLUIDIC FORMATION OF
CELL-LADEN HYDROGEL MODULES
FOR TISSUE ENGINEERINGHTTPS://WWW.RESEARCHGATE.NET/PROFILE/SITANSU_NANDA3
HTTP://SCHOLAR.GOOGLE.CO.KR/CITATIONS?USER=EPAML2OAAAAJ&HL=EN
2. INTRODUCTION
■ Hydrogels are commonly used for cell cultures because they are mostly a biocompatible, biodegradable, hydrophilic material and have a
porous matrix.
■ Moreover, because the size, shape, porosity, and chemical properties of hydrogels can easily be designed according to specific requirements,
hydrogels are ideal materials for providing in vivo-like environments.
■ Recently, micro fabricated hydrogel modules are used as attractive microenvironments when culturing living cells; these hydrogel modules
allow cells to attach on their surfaces or to be encapsulated (or both).
■ This section provides an overview of
(1) fabrication methods and characteristics of cell-laden hydrogel micro modules,
(2) handling techniques of the modules in microfluidic devices, and
(3) applications of the modules for transplantation and bottom-up tissue engineering.
4. TYPES OF HYDROGELS
Hydrogels are mainly categorized into two types: hydrogels based on
natural polymers and hydrogels based on synthetic polymers.
Among the hydrogels obtained from natural polymers, collagen,
hyaluronate, fibrin, alginate, and agarose are potentially attractive
for tissue engineering applications. Collagen and hyaluronate are
tissue-derived natural polymers and components of the ECMs.
Collagen gelates in response to temperature change. Hyaluronate
gelates by covalent cross-linking with hydrazide derivatives and
radical polymerization of glycidyl methacrylate.
Fibrin is a protein found in blood and gelates by the enzymatic
polymerization of fibrinogen. Alginate and agarose are plant-derived
natural polymers obtained from algae.
5. ■ Hydrogel Beads: (a) Schematic illustration of the formation monodisperse droplets using the T junction microchannel and images of
droplet formation at the T-junction taken by a high-speed video camera. (b) Size distribution of the alginate gel beads produced by the
T-junction device. The alginate gel beads show monodispersed (CV¼2.8%). (c) Monodisperse alginate gel beads encapsulating Jurkat
cells. The beads are also of a narrow size distribution. (d) Schematic view of the 2D flow-focusing device and images of droplet
formation in a flow focusing device. In the 2D flow-focusing device, the droplets produced come into contact with the top and bottom of
the channel walls. Therefore, the wetting problem occurs. (e) Schematic diagram of an AFFD used to produce monodisperse droplets.
AFFDs can prevent droplets from adhering to the surface of the channels because the droplets are always surrounded by the outer fluid.
(f) Plot of the sizes of the alginate gel beads in the oil versus the flow rate ratio (outer flow rate/inner flow rate). CVs of every point are
less than 5%, indicating all beads produced by the AFFD are monodisperse. (g) Image of alginate gel beads in oil corresponding to (g) in
figure (f). (h–i) Formation of monodisperse agarose gel beads.
MICROFLUIDIC DEVICES FOR HYDROGEL MODULE
PRODUCTION
6.
7. Hydrogel Blocks: To produce hydrogel blocks,
photolithography, flow lithography, and micro molding
techniques are mainly used. Photolithography has a fast and
high-resolution (1 mm) performance in forming hydrogels
with various shapes and sizes. In the photolithography
technique, the sol solution is initially molded into block shape
and polymerized by using ultraviolet (UV) light. Because UV
light triggers gelation, photo cross-linkable micro gels such as
PEG should be used in this technique. The plane shape of the
hydrogel blocks is obtained from the photomask design, and
their depth follows the depth of the mold. Moreover, the plane
shape of the depth direction can be controlled by changing the
focus depth of UV light and the photomask patterns.
Therefore, photolithography can produce complicated
structures such as polygons and rotundate blocks.
8. Hydrogel Fibers and Tubes: (a) Image of 3D-pattern hydrogel blocks
fabricated by photolithography. The plane shape and depth of blocks are not
only changed by the photomask design and the mold depth, respectively, but
the plane shape of depth direction is also controlled by the altered focus depth
of the UV light and light path. Scale bar, 50mm. (b) Image of hydrogel blocks
formed by flow lithography. The shape of blocks can be easily varied
according to the photomask design. The scale bar for all panels is 10mm. (c)
Schematic fabrication procedure of hydrogel fibers. (d) Image of the alginate
fiber. Scale bar, 200mm. (e) Optical bright field and fluorescence image of
alginate fiber containing Wharton’s jelly mesenchymal stem cells. (f)
Schematic diagram of the microfluidic device that generates the alginate gel
tubes. Coaxial flow composed of core and sample flows is generated, and
gelling of the alginate sol in the sample flow starts at the interface of both
flows. After the sheath flow surrounds the coaxial flow, solidification occurs
simultaneously at the interface between the sample flow and the sheath flow.
(g) Scanning electron microscopic image of the hydrogel tube. (h) Image of
serially coded fiber and its close-up image. Scale bars, 1mm and 400mm
(close-up image). (i) Image of parallel coded fiber. Scale bar, 200mm. (j)
Image of a fiber with spatiotemporal variations in morphology and chemical
composition. Scale bar, 1mm. (h–j) Each type of fluorescent polystyrene beads
emits different colors: red, blue, and green.
9. Cell Analysis Using Microfluidic Devices
(a) Schematic diagram of a meander-shaped hydrodynamic microfluidic
device. When the trapping area is empty, a bead in the mainstream is
delivered into the trapping area. When the trapping area is full, beads are
carried along the meander-shaped main channel. (b) Superimposed time-
lapsed high-speed camera image showing the trapped beads. (c) Sequence
images taken by a high-speed camera indicating the retrieval of beads
using bubbles. (d) Image of monodisperse hollow capsules comprising a
PLL-alginate membrane and the encapsulating microbe, Chlamydomonas.
The path traced by Chlamydomonas in 3 s is shown. The image shows that
the motility of the encapsulated microbes is not compromised inside the
hollow capsule. In addition, continuous observation was carried out for
more than 2 h. (e) Schematic view of the improved meander-shaped
hydrodynamic device that allows different types of hydrogel beads to be
paired. (f) Fluorescent images of collagen gel beads with stained cells
paired with different types of cells. Red indicates HepG2 cells and green
indicates 3T3 cells.
10. (a) Schematic diagram of transplantation using
cell-laden hydrogel modules. Because hydrogel
protect the invasion of immune antibodies,
encapsulated cells can live for a long time without
immune reactions.
(b) Laparoscopic view of the omentum of a patient
with type 1 diabetes 9 years after transplantation
of alginate capsules encapsulating porcine islets.
(c) Fiber is implanted in the mouse ear to
continuously monitor the glucose level.
(d) The implanted fiber is easily removed from the
ear.
(e) Fluorescent image of the mouse ear containing
the fiber. The fiber transmits fluorescent signals
continuously depending on blood glucose
concentration.
(f) Fluorescent image of the mouse ear after fiber
removal. The image shows that the implanted
fibers are retrieved from the ear without leaving
debris.
11. (a, b) Fluorescence confocal microscopy of hierarchical co cultured cell beads. (a) Collagen gel beads encapsulating HepG2 cells
(red) and seeded with 3T3cells (green) after 17 h of incubation. (b) Self-assembling peptide beads containing endothelial cells
(red) and 3T3 cells (green) after 2 days of culture. (c) Fluorescent image of a collagen gel rod seeded with HUVEC cells showing
the rod covered with a confluent cell layer. (d) Image of the modular construct, including the microporous body. (e) Schematic
suggesting assembly of cell-laden hydrogel blocks in oil. Mechanical agitation applied using a pipette tip and secondary cross-
linking form diverse shapes of gel assemblies: random, branched, linear, and offset. (f, g) Images of the lock-and-key-shaped gel
assembly containing three rods per cross. Cross-shaped gel and rod-shaped gel encapsulates red-labeled and green-labeled 3T3
cells, respectively. Scale bars, 200 mm. (h) Schematic diagrams of the assembly of cell-laden hydrogel blocks to form lined-
shaped cell structures in a microfluidic device. (i) Image of the line-shaped cell structure consisting of three differently labeled
cells. (j) Scanning electron microscope image of the microtrain. (k) Guided movement of microtrain along a reentrant rail. (l)
Image of the Eiffel Tower assembly produced by the guided assembly method. (m) Image of the rail-guided assembly including
two different types of living cells. Green and red indicate HeLa and HEK293 cells, respectively.
12.
13. a) Concept of bead-based tissue engineering: monodisperse cell beads are
molded into a macroscopic cell structure. (A, B) Monodisperse cell beads
are poured into a designed PDMS mold. (C) During tissue formation, the
medium diffuses inside the 3D cell structures via the cavities of the cell
beads, supplying nutrients to all cells. (D) Macroscopic 3D cell structures
are released from the PDMS mold. (b) Image of cell beads seeded with 3T3
cells; they are the building modules for the construction of a macroscopic
3D cell culture. (c) Fluorescent image of the macroscopic structures having
a complicated shape. Live-dead assay staining indicates that almost all cells
within the structure are alive. (d, e) Ring- and tube shaped cell structures
fabricated by the printing method. (f) Tube-shaped hierarchical co culture
structures made from printing cells. The inner layer is composed of human
umbilical endothelial cells (green), and the outer layer is composed of
human aortic smooth muscle cells (red).
14. ■ Microfluidic techniques succeed in reproducibly constructing diversely shaped hydrogel modules such
as beads, blocks, fibers, tubes, and sheets with high throughput, high uniformity, and design flexibility.
These hydrogel modules have applications in various fields ranging from basic biology studies to
tissue engineering.
■ Combined with cell assay microfluidic systems and cell-laden hydrogel modules, micro tissues with
ECM are useful for analyses of cell functions and cell–cell interactions because micro tissues can
easily be handled, arrayed, and retrieved in microfluidic systems. Furthermore, the cell-laden hydrogel
modules can be used as building units for reconstructing 3D cell structures. Therefore, the cell-laden
hydrogel modules produced by microfluidic devices have a great potential to create miniaturized
tissues for human implantation and for treatment of diseases.
CONCLUSION
MICRO- AND NANOTECHNOLOGIES TO ENGINEER BONE REGENERATION