3D bioprinting shows promise for applications in orthopaedics such as cartilage and bone regeneration. For cartilage, bioprinting can replicate the complex zonal structure of native tissue by printing cells and extracellular matrix layer-by-layer. For bone, combinations of biomaterials in hybrid scaffolds can mimic native bone properties. Bioprinting is also being explored for meniscus, intervertebral discs, and other orthopaedic tissues to address limitations of current treatment options.
There are a lot of orthopedic conditions and injuries that presently have limited treatment options available.
Here regenerative technologies comes up as a ray of hope among surgeons for the treatment by functionally repairing the tissues and organs using growth factors, stem cells and products developed by genetic engineering with the advancement in the stem cells research field .
The purpose of this presentation is to first provide idea about the orthopedic conditions along with the therapeutic potential of stem cells to treat these diseases.
There are a lot of orthopedic conditions and injuries that presently have limited treatment options available.
Here regenerative technologies comes up as a ray of hope among surgeons for the treatment by functionally repairing the tissues and organs using growth factors, stem cells and products developed by genetic engineering with the advancement in the stem cells research field .
The purpose of this presentation is to first provide idea about the orthopedic conditions along with the therapeutic potential of stem cells to treat these diseases.
It has been expleined in these slides that how 3D bioprinters work and some of them have been introdused. Also some examples of use 3D bioprinter in reality are introduced.
Finally feature of 3D bioprinters in human life has been explained.
Dynamic Stabilization in the Surgical Management of Painful Lumbar Spinal Dis...Alexander Bardis
Current surgical management of the painful lumbar motion segment is imperfect.
Improvements are necessary :
in the predictability of pain relief, the reduction of treatment related morbidities, and an overall improvement in the clinical success rates of :
pain reduction and functional improvement.
This video explains Lumbar Disc Replacement in Detail. When degenerative disc disease begins to affect the spine this is called degenerative disc disease. This video highlights the history, epidemiology, and treatment options both conservative and surgical. If you or someone you know needs to be seen in regards to Lumbar Disc Replacement feel free to look us up online www.beverlyspine.com or www.santamonicaspine.com OR call toll free 1-8SPINECAL-1
3D Bioprinting in Disease Prevention & Treatment.pdfDoriaFang
Learn about 3D bioprinting in disease prevention and treatment from 3D bioprinting materials, 3D bioprinting technology and 3D bioprinted vaccines, therapeutics and delivery systems.
It has been expleined in these slides that how 3D bioprinters work and some of them have been introdused. Also some examples of use 3D bioprinter in reality are introduced.
Finally feature of 3D bioprinters in human life has been explained.
Dynamic Stabilization in the Surgical Management of Painful Lumbar Spinal Dis...Alexander Bardis
Current surgical management of the painful lumbar motion segment is imperfect.
Improvements are necessary :
in the predictability of pain relief, the reduction of treatment related morbidities, and an overall improvement in the clinical success rates of :
pain reduction and functional improvement.
This video explains Lumbar Disc Replacement in Detail. When degenerative disc disease begins to affect the spine this is called degenerative disc disease. This video highlights the history, epidemiology, and treatment options both conservative and surgical. If you or someone you know needs to be seen in regards to Lumbar Disc Replacement feel free to look us up online www.beverlyspine.com or www.santamonicaspine.com OR call toll free 1-8SPINECAL-1
3D Bioprinting in Disease Prevention & Treatment.pdfDoriaFang
Learn about 3D bioprinting in disease prevention and treatment from 3D bioprinting materials, 3D bioprinting technology and 3D bioprinted vaccines, therapeutics and delivery systems.
Characterization of effective mechanical strength of chitosan porous tissue s...ijbesjournal
Tissue engineering can be understand as the development of functional substitute to replace missing or malfunctioning human tissue and organs by using biodegradable or non-biodegradable biomaterials such
as scaffolds to direct specific cell types to organize into three dimensional structures and perform
differentiated function of targeted tissue. The important factors to be considered in designing of
microstructure and there structure material were type of bio-material porosity, pore size, and pore
structure with respect to nutrient supply for transplanted and regenerated cells. Performance of various
functions of the tissue structure depends on porous scaffold microstructures with dimensions of specific
porosity, pore size, characteristics that influence the behaviorand development of the incorporated cells.
Finite element Methods (FEM) and Computer Aided Design (CAD) combines with manufacturing
technologies such as Solid Freeform Fabrication (SFF) helpful to allow virtual design and fabrication,
characterization and production of porous scaffold optimized for tissue replacement with appropriate pore
size and proper dimension. In this paper we found that with the increase in the porosity of tissue
scaffolds(PCL, HAP, PGAL & Chitosan) their effective mechanical strength decreases by performing the
modeling & simulation with CAD & FEM package (Pro/E & ANSYS respectively) and validating the results with in vitro fabrication of Chitosan scaffold by performing in vivo mechanical testing.
Bioreactors are devices in which biological or biochemical processes develop under a closely monitored and tightly controlled environment. Bioreactors have been used in animal cell culture since the 1980s in order to produce vaccines and other drugs and to culture large cell populations. Bioreactors for use in tissue engineering have progressed from such devices.
A tissue engineering bioreactor can be defined as a device that uses mechanical means to influence biological processes. In tissue engineering, this generally means that bioreactors are used to stimulate cells and encourage them to produce extracellular matrix (ECM). There are numerous types of bioreactor which can be classified by the means they use to stimulate cells.
Advances at the intersection of mechanical engineering and biomedical science with overview and case studies of 3D-bioprinting, prosthetics, and implants.
3D-Bioprinting coming of age-from cells to organsDaniel Thomas
Over the past decade, annual spending on pharmaceutical development to treat many endocrinological systems has increased exponentially.
Currently, preclinical studies to test the safety and efficiency of new drugs, use laboratory animals and traditional 2D cell culture models. Neither of these methods are completely accurate reflections of how a drug will react in a human patient.
A solution has emerged in the form of 3D-Bioprinting technology, developed for the scalable, accurate and repeatable deposition of biologically active materials. With advances in this biomanufacturing technology, durable biological tissues for use in testing new pharmaceutical products are now being harnessed and refined.
3D Bio-printing of cells, tissue and organs. Bioprinting (also known as 3D bioprinting) is combination of 3D printing with biomaterials to replicate parts that imitate natural tissues, bones, and blood vessels in the body. It is mainly used in connection with drug research and most recently as cell scaffolds to help repair damaged ligaments and joints.
With the pandemic overclouding the whole world it has effected every strato of people including the Orthopaedic groups. This is to highlight the impact of COVID 19 on the orthopaedic in general.
Conservative management in 3 and 4 part proximal humerus fractureBipulBorthakur
Proximal humerus fracture is common in both young as well as elderly people with most of the elderly patients unable to undergo operative management. This study is to see the aspect of conservative management in proximal humerus fracture.
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
263778731218 Abortion Clinic /Pills In Harare ,sisternakatoto
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NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
2. INTRODUCTION
3-dimensional (3D) printing, is the process of engineering objects layer by layer to produce a
specific functional product.
Since its inception in 1986, the process of 3D printing has expanded rapidly and has
positively impacted multiple fields of engineering and manufacturing .
Use of 3D printing in orthopaedics includes the fabrication of custom casts and braces, the
production of surgical templates, the design and manufacture of patient specific arthroplasty
instrumentation, the design of custom total joint arthroplasty implants.
3. INTRODUCTION
Three-dimensional-printing technology has evolved dramatically in the last 30 years from rudimentary
selective laser sintering printers to current printers that are able to create 3D products with living
components through a process called 3D bioprinting (3DBP).
4. 3DBP – BASIC PRINCIPLES
The basis of 3DBP relies on concepts of biomimicry and biologic self-assembly.
Biomimicry is the concept that a product should mimic the desired native tissue. Each specific cell and
tissue type must be accounted for, and proper cellular signaling is promoted by extrinsic environmental
factors that help to replicate the target tissue.
Self-assembly is the concept that if the proper cells and components are in place, the desired tissue will
form as a result of cells and tissues having inherent mechanisms for maturation and development.
Three-dimensional bioprinting can utilize a scaffold or be scaffold-free.
5. SCAFFOLD PRINTING
Scaffold-type printing uses cells in an inert medium, which are seeded onto a premade scaffold.
These mixtures of cells in an inert medium are known as bioinks, and they are the foundation of 3DBP9 .
The inert media are usually hydrogels, which have various properties depending on the biomaterials that
are included.
6. SCAFFOLD PRINTING
Hydrogels are defined as “water-swellable, water-insoluble, cross-linked networks” of polymers that can
provide multiple advantages in tissue engineering by supporting cell viability and differentiation.
Scaffolds are appealing as they represent a volume-stable construct. They have an excellent ability to
control the spatial structure of tissues and create a robust extracellular matrix (ECM)
7. SCAFFOLD FREE PRINTING
Scaffold-free techniques utilize microscopic tissue units, such as cell spheroids or pellets.
These are deposited onto a substrate and mature to form functional tissue.
Spheroids are produced by self-assembly processes through adhesion molecules in cell culture that mimic
the natural processes of embryogenesis, morphogenesis, and organogenesis.
8. Bioprintring processes and techniques
The desired 3D digital file is created, usually from computed tomography (CT) or magnetic resonance
imaging (MRI), and exported into a 3D digital file.
The production of the desired target tissue includes the selection of the type of printer to be used as well
as the type and combination of the components (bioink, scaffold versus scaffold-free, growth factors, and
cell types).
9. Bioprintring processes and techniques
Bioprinter technology can be classified as
inkjet/droplet,
laser assisted, or
extrusion-based.
The selection of printer type is made with consideration of the target tissue that is to be replicated.
10. Inkjet Bioprinter
Inkjet printers use either thermal or piezoelectric energy to create droplets of bioink that are propelled
through a nozzle.
11. Extrusion- based Bioprinter
Extrusion-based bioprinting (EBB), the most basic method of bioprinting
It involves building pressure in a reservoir and using either a screw or pneumatic cylinder to dispense the
bioink.
These printers continuously dispense bioink onto a collecting surface to construct a final product.
13. Laser- assisted Bioprinter
Laser-assisted bioprinting (LAB) is a method of bioprinting in which a laser source fires a direct and
focused beam of energy onto a ribbon that contains bioink.
The ribbon contains a metal covering that absorbs the energy and transfers it to the bioink, forming a
bubble that propels the bioink.
LAB is highly precise, and resolution as high as 1 cell per droplet has been reported, allowing for
structures of varying cell types to be printed in close proximity to one another.
15. Clinical applications: Articular cartilage
Use of 3DBP represents an innovative approach for articular cartilage restoration; however, the unique
biology of this tissue provides challenges.
Hyaline cartilage is on average 2 to 4 mm thick; it is avascular and aneural and is comprised of ECM and
chondrocytes.
This ECM contains collagen, proteoglycans, and glycoproteins in varying concentrations and orientations
based on the depth of the cartilage. This unique composition allows for the retention and intrasubstance
movement of water, which is critical to the anisotropic and viscoelastic properties of cartilage.
16. Articular cartilage
Injured articular cartilage is associated with an unpredictable and potentially disordered capacity to heal.
Currently, there is one commercially available synthetic cartilage implant, CARTIVA SCI (cartiva), which
is an acellular molded polyvinyl alcohol hydrogel. CARTIVA was approved to treat patients with hallux
rigidus, but it has failed to achieve consistent clinical success.
Recent advances in 3D printing have contributed techniques that will allow for the production of materials
that more closely replicate native cartilage.
17. Articular cartilage
Prior cartilage tissue engineering methods involved printing or molding the ECM components in the
desired shape and then adding cells to the matrix; however, this does not mimic the native architecture.
Now, bioprinters can print cells along with ECM-like material layer by layer to more closely replicate the
complex and unique zonal ultrastructure of cartilage.
18.
19. Bone:
Bone defects as a result of trauma, tumor resection, and infection represent a common treatment
challenge.
At present, options for the management of bone defects are limited to the use of bone autografts and
allografts.
Use of autogenous bone graft is potentially limited by the extent of bone that is available and donor-site
morbidity.
Allogenic bone grafts are associated with the potential for disease transmission, and there is limited
availability and a high cost.
20. Bone :
Multiple different materials (bioceramics such as calcium phosphate [cap], tricalcium phosphate [tcp], and
hydroxyapatite [hap]) that are currently used clinically as bone substitutes.
These bone substitutes are osteoconductive given their chemical similarity to the apatite crystals of bone;
however, their lack of live cells means that they are not osteoinductive, and they have other issues, such as
partial disintegration when exposed to body fluids.
Because of the limitations of each of these methods, bone restoration through tissue engineering has been
a focus of extensive research.
21. Bone :
Although scaffold-free bioprinting seems ideal for bone tissue engineering because it allows for precise
control over porosity and deposition of cells and biomaterials, constructs often lack compressive strength.
Given the initial structural integrity that can be provided by using scaffolds and the relative infancy of
scaffold-free bioprinting, much of the bone bioprinting research revolves around 3d-printed scaffolds that
are seeded with cells after production.
Since neither bioceramics nor polymers are perfect for bone tissue engineering, many combinations of
materials have been combined as hybrid materials for scaffold formation, and some have been found to
have properties very similar to native bone
22. Bone :
Bioinks made from polymers such as alginate, collagen, or gelatin have been the focus of scaffold-free
techniques because of their structural similarities to bone ECM.
Poor compressive strength remains an issue, but the addition of other biomaterials to the base bioink, the
cross-linking of polymers, and post-processing compressive loading have been useful in transforming
them into more mechanically effective constructs.
The addition of biomaterials can concurrently increase compressive strength and osteoconductivity (e.g.,
With the addition of HAp, TCP, and/or bioactive glass). Osteoinductive elements, including growth factors
like BMPs, also have been incorporated to guide differentiation of the precursor cells that are included in
the bio-ink.
23. Bone :
Providing vascularity to support the synthetic graft once it has been implanted is a challenge in bone tissue
engineering, especially for the generation of larger grafts.
To remedy this issue, researchers have created vessel-like structures that can be lined with endothelial
cells to promote vascularization.
The introduction of endothelial cells can cause the formation of microcapillaries, and self-assembly of
capillaries in bioprinted bone has been accomplished through this technique.
24. Bone :
One methodology includes coculture of human umbilical vein endothelial cells (HUVECS) with
mesenchymal stem cells (MSCs), along with both osteogenic growth factors and vasculogenic factors,
usually vascular endothelial growth factor (VEGF).
Through this method, several investigators recently have produced osteogenic and vasculogenic niches
within the same printed tissue, and this process has been deemed “prevascularization”
25.
26. Meniscus:
Many meniscal tear patterns may be reparable; however, for patients with substantial meniscal tissue loss,
replacement through allogeneic transplantation is the gold-standard treatment option.
Allograft transplantation is associated with limited tissue availability, immunogenicity, and impaired
remodeling capacity.
There are 2 acellular meniscal substitute scaffolds that are commercially available in the united states;
however, their use is considered controversial.
27. Meniscus:
These scaffolds are the collagen meniscus implant (CMI; stryker), made from bovine achilles tendon
collagen and gags, and the actifit (orteq sports medicine), made from a poly-«-caprolactone (PCL) and
polyurethane blend.
Multiple authors have reported on bioprinting models of menisci that are based on MRI. The results have
shown variable cell viability within the tissue constructs.
Filardo et al. Printed a bioink of collagen and MSCs using an inkjet printing technique and showed that
although cell viability was 50% after printing, likely due to processing temperatures, there was no
additional loss in viability.
28. Meniscus:
Markstedt et al. Created a bioink from nanocellulose and alginate, and bioprinted it along with human
nasoseptal chondrocytes into the shape of sheep menisci, demonstrating 70% cell viability.
Chansoria et al. Used alginate and human adipose stem cell (ASC) bioink with a novel technique of
ultrasound-assisted bioprinting to print meniscal tissue with 100% cell viability
29. Meniscus:
Romanazzo et al. Described a biphasic meniscal tissue construct made with ECM from porcine menisci
that was seeded with infrapatellar fat-padderived stem cells with added connective tissue growth factor
(CTGF) for the periphery and TGF-ß3 for the inner meniscal tissue.
After bioprinting, histologically the inner and peripheral meniscal tissue resembled the native meniscus in
terms of collagen and GAG expression.
Compressive strength was low for the bioink alone, but when combined with PCL, a 100-fold increase in
strength was noted, giving the tissue a compressive modulus near the 0.1 to 1 MPa of native meniscal
tissue. Cell viability was 80% to 90% in the final constructs.
31. Intervertebral disc:
Degenerative disease of the intervertebral disc (IVD) of the spine is a common cause of back pain
Surgical treatment options include spinal fusion, discectomy, and total disc replacement.
All of these treatment options have advantages and disadvantages; hence, the potential to create a tissue-
engineered (TE)-IVD is a compelling area of research.
32. Intervertebral disc:
Challenges encountered in creating a TE-IVD are replicating the highly aligned collagen organization of
the anulus fibrosus, matching the size and shape to the native disc, optimizing mechanical properties of
both the synthetic anulus fibrosus and nucleus pulposus tissue, and combining the synthetic anulus
fibrosus and the nucleus pulposus into a composite TE-IVD.
Multiple different approaches have been utilized, including the use of electrospun nanofibrous PCL,
wetspinning and lyophilization of alginate/ chitosan, and contraction of anular collagen gels to create
scaffolds with architecture similar to the native anulus fibrosus
33. Intervertebral disc:
PCL continues to be a popular polymer for anulus fibrosus tissue engineering due to its high young’s
modulus, which is similar to the native anulus fibrosus.
Christiani et al. used 3D-printed scaffolds of PCL with differing angular orientations of polymer fibrils
and were able to create constructs that have axial compressive and circumferential tensile properties that
are similar to the native anulus fibrosus.
Choy and chan showed that varying the number of cross-linked collagen lamellar rings in the scaffold
impacted biomechanical properties. They found that 10 anulus-like lamellae created a scaffold with elastic
compliance that was nearly identical to the native anulus fibrosus.
34. Intervertebral disc:
Different combinations of biomaterials have been reported to create biphasic scaffolds that mimic the
anulus fibrosus and the nucleus pulposus of native IVD.
Hyaluronic acid, fibrin-hyaluronan gel, alginate, and collagen-GAG coprecipitate all have been utilized to
create synthetic nucleus pulposus as part of biphasic synthetic IVD.
35. Intervertebral disc:
Du et al. seeded a PCL/alginate biphasic IVD scaffold with rabbit anulus fibrosus and nucleus pulposus
cells and showed that the anulus fibrosus cells colonized the PCL scaffold while the nucleus pulposus
cells colonized the alginate hydrogel.
Blanquer et al. Used 3d-printed scaffolds of poly(trimethylene carbonate) to mimic the anulus fibrosus
and then seeded them with human-adipose-derived stem cells and induced differentiation into anulus
fibrosus-like cells using TGF-ß3. They showed that these anulus fibrosus-like cells produced collagen and
GAG in a ratio comparable with human anulus fibrosus.