1) A microfluidic device was used to separate cardiac cell populations from neonatal rat hearts based on cell size.
2) The device consisted of a middle channel connected to side channels by microsieves. Non-myocytes were enriched in the side channels while myocytes remained in the middle channel due to size-based filtration.
3) Cells from the middle and side channels maintained viability, attached in culture, and expressed markers characteristic of myocytes and non-myocytes, respectively, demonstrating the feasibility of size-based microfluidic separation of cardiac cell types.
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.
Stem Cells,BMAC,PRP,Scaffold,Regenerative Medicine,Chondrocytes,Mesenchymal cells,FUTURE ORTHOPEDICS BASICS OF STEM CELLS AND TISSUE ENGINEERING Dr.Sandeep C Agrawal Gondia Maharashtra India
Micro and nanoengineering approaches to developing gradient biomaterials sui...Dr. Sitansu Sekhar Nanda
Interface tissue found between soft and hard tissue regions such as cartilage-bone, tendon-bone, ligament-bone and other tissues. (e.g. dentin-enamel). Conventional Biomaterials are monophasic or composite materials are inefficient facilitating tissue formation. So, gradient materials are required for interface tissue engineering.
Development of cancer therapeutics is often carried out in 2D cultures prior to testing on animal model. In comparison to 2D cultures, discuss the potential of using 3D in vitro models for drug efficiency testing.
Autologous Mesenchymal Stem Cells in OrthopaedicsVladimir Bobic
Nuffield Health, The Grosvenor Hospital Chester, UK
27 June 2013. GP and Physiotherapy Seminar: Autologous Stem Cell Therapies in Orthopaedics. Moderator and Presenter: Vladimir Bobic, Chester Knee Clinic
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.
Stem Cells,BMAC,PRP,Scaffold,Regenerative Medicine,Chondrocytes,Mesenchymal cells,FUTURE ORTHOPEDICS BASICS OF STEM CELLS AND TISSUE ENGINEERING Dr.Sandeep C Agrawal Gondia Maharashtra India
Micro and nanoengineering approaches to developing gradient biomaterials sui...Dr. Sitansu Sekhar Nanda
Interface tissue found between soft and hard tissue regions such as cartilage-bone, tendon-bone, ligament-bone and other tissues. (e.g. dentin-enamel). Conventional Biomaterials are monophasic or composite materials are inefficient facilitating tissue formation. So, gradient materials are required for interface tissue engineering.
Development of cancer therapeutics is often carried out in 2D cultures prior to testing on animal model. In comparison to 2D cultures, discuss the potential of using 3D in vitro models for drug efficiency testing.
Autologous Mesenchymal Stem Cells in OrthopaedicsVladimir Bobic
Nuffield Health, The Grosvenor Hospital Chester, UK
27 June 2013. GP and Physiotherapy Seminar: Autologous Stem Cell Therapies in Orthopaedics. Moderator and Presenter: Vladimir Bobic, Chester Knee Clinic
Virtual museums and educational online environmentsGreg Jones
Results from 2010-11 pilot study on virtual museum education related to knowledge acquisition. Journal article is in-press. It examines the effectiveness, usability, and knowledge acquisition between the Leopoldo Flores Museum, located at the UAEM, and an online virtual environment replica. The primary results show a) students using the virtual environment first and then visiting the museum exhibited better knowledge acquisition about the museum and had higher level of discourses when on the guided tour, and b) the virtual museum experience, when used alone, was a comparable experience to the actual museum guided tour in both knowledge gained and satisfaction.
International Journal of Stem Cell Research and Transplantation (IJST) is an international, Open Access, peer-reviewed journal, which mainly focuses, on the advancements made in the field of cell biology, specifically in the field of Stem Cells.
International Journal of Stem Cell Research and Transplantation (IJST) is a peer-reviewed journal, and is dedicated to providing information with respect to the latest advancements that are being upgraded in our everyday life with respect to the application of Stem cells.
International Journal of Stem Cell Research and Transplantation (IJST) ISSN:2328-3548, is a free, Open Access, Peer-reviewed, exclusive online journal covering areas of Stem cell research, translational work and Clinical studies in the specialty of Stem Cells and Transplantation including allied specialties relevant to the core subject, which is dedicated in publishing high quality manuscripts.
International Journal of Pharmaceutical Science Invention (IJPSI) is an international journal intended for professionals and researchers in all fields of Pahrmaceutical Science. IJPSI publishes research articles and reviews within the whole field Pharmacy and Pharmaceutical Science, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online.
DIFFUSION BASED AND VASCULAR CONSTRUCTS, TRANSPORT OF NUTRIENTS AND METABOLITES Vijay Raj Yanamala
Tissue Engineering is the study of the growth of new connective tissues, or organs, from cells and a collagenous scaffold to produce a fully functional organ for implantation back into the donor host. It also refers to the application of engineering principles to the design of tissue replacements, usually formed from cells and biomolecules. Tissue engineering is a fast growing area of research that aims to create tissue equivalents of blood vessels, heart muscle, nerves, cartilage, bone, and other organs for replacement of tissue either damaged through disease or trauma. As an interdisciplinary field, principles from biological, chemical, electrical, materials science, and mechanical engineering are employed in research and development. Concepts and discoveries from the fields of molecular and cell biology, physiology and immunology are also readily incorporated into research activities for tissue engineering. Recent advancements in stem cell research provide exciting opportunities of using stem cells for regeneration of tissues and organs.
The ECIS is a turnkey system that provides researchers with an advanced, automated, non-invasive means to monitor cell behavior in real-time and without the use of labels.
Mammalian MSC from Selected Species: Features and Applications
Christiane Uder, Sandra Br€uckner, Sandra Winkler, Hans-Michael Tautenhahn,†‡ Bruno Christ†*
Mesenchymal stromal/stem cells (MSC) are promising candidates for cellular therapy of different diseases in humans and in animals. Following the guidelines of the International Society for Cell Therapy, human MSC may be identified by expression of a specific panel of cell surface markers (CD1051, CD731, CD901, CD34-, CD14-, or CD11b-, CD79- or CD19-, HLA-DR-). In addition, multiple differentiation potential into at least the osteogenic, adipogenic, and chondrogenic lineage is a main criterion for MSC definition. Human MSC and MSC of a variety of mammals isolated from different tissues meet these criteria. In addition to the abovementioned, they express many more cell surface markers. Yet, these are not uniquely expressed by MSC. The gross phenotypic appearance like marker expression and differentiation potential is similar albeit not identical for MSC from different tissues and species. Similarly, MSC may feature different biological characteristics depending on the tissue source and the isolation and culture procedures. Their versatile biological qualities comprising immunomodulatory, anti-inflammatory, and proregenerative capacities rely largely on the migratory and secretory capabilities of MSC. They are attracted to sites of tissue lesion and secrete factors to promote self-repair of the injured tissue. This is a big perspective for clinical MSC applications in both veterinary and human medicine. Phase I/II clinical trials have been initiated to assess safety and feasibility of MSC therapies in acute and chronic disease settings. Yet, since the mode of MSC action in a specific disease environment is still unknown at large, it is mandatory to unravel the response of MSC from a given source onto a specific disease environment in suitable animal models prior to clinical applications.
Journal of Stem Cells Research, Reviews & Reports is a peer-reviewed, open access journal published by Austin Publishers. It provides easy access to high quality Manuscripts in all related aspects covering Stem cell research that focuses on stem cells, which have a capacity to regenerate and develop into other types of cells namely, like kidney cells, liver cells, heart cells, etc. These circulate and function to replace dysfunctional cells, naturally maintaining optimal health. The Journal encourages all the current medical research that is focused on two particular types of stem cells -- adult and embryonic stem cells that are used in various stem cell therapies against many dreadful diseases.
Austin Publishing Group is a successful host of more than hundred peer reviewed, open access journals in various fields of science and medicine with intent to bridge the gap between academia and research access.
Journal of Stem Cells Research, Reviews & Reports accepts original research articles, review articles, case reports, mini reviews, rapid communication, opinions and editorials on all the related aspects of Stem Cells and Cell-Based Therapies.
The Acoustic Technology for Ctcs Isolation in Blood: Low-Cost Devices_Crimson...CrimsonpublishersCancer
Blood samples can be used as a liquid biopsy in cancer diagnosis and chemotherapy monitoring. This label- free method offers benefits over traditional tissue invasive biopsy. It is possible to separate rare cells from blood samples by Ultrasounds on the basis of their physical properties in a biocompatible manner. A successful separation of cultured cancer cells from WBCs with acoustic-based methods is being demonstrated during the last years through different technological approaches. The concept of plate acoustic waves (PAW) applied to acoustophoresis was recently introduced to perform acoustic flow-through separation of rare cells in blood samples. It lies in the geometrical chip design, different to other micro separators (BAW and SAW). This new strategy allows soft materials of extremely reduced volume and low-cost fabrication and opens a door to printing manufacturing processes.
Rotator cuff repair using a stem cell approachZakary Bondy
This presentation communicates current methods for rotator cuff repair mainly focusing on mesenchymal and tendon-derived stem cells. It looks to expand on future research in this field by communicating a future experiment to expand on current knowledge of tendon-derived stem cells.
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.
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.
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
The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
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
263778731218 Abortion Clinic /Pills In Harare ,sisternakatoto
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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.
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists
Nanomedicina9
1. Biomed Microdevices (2006) 8:231–237
DOI 10.1007/s10544-006-8169-5
Size-based microfluidic enrichment of neonatal rat cardiac cell
populations
Shashi K. Murthy · Palaniappan Sethu ·
Gordana Vunjak-Novakovic · Mehmet Toner ·
Milica Radisic
Published online: 19 May 2006
C Springer Science + Business Media, LLC 2006
Abstract Native heart consists of myocytes and non- ing sorting and the ability to attach and grow in culture.
myocytes. We demonstrate here the feasibility of a size-based Upon culture for 48 h cardiomyocytes from the reservoir
microfluidic separation of myocytes and non-myocytes from (control) and middle channel stained positive for cardiac
the neonatal rat myocardium. The device consists of a mid- Troponin I, exhibited a well developed contractile appara-
dle channel (50 μm wide, 200 μm tall, and 4 cm long) con- tus and contracted spontaneously and in response to electri-
nected to adjacent side channels by microsieves (80 μm wide, cal field stimulation. Most of the cells in the side channel
5 μm tall and 40 μm in length). The side channels increase expressed a non-myocyte marker vimetin. Fluorescent acti-
in width in a flared shape along the length of the device to vated cell sorting indicated significant enrichment in the side
ensure constant pressure gradient across all sieves. In the channel ( p < 0.001) for non-myocytes. Original cell sus-
first step, non-myoctes were removed from the myocytes pension had a bimodal cell size distribution with the peaks
by a conventional pre-plating method for 75 min. Subse- in the range from 7–9 μm and 15–17 μm. Upon cell sort-
quently, the non-myocytes were further enriched in a mi- ing the distribution was Gaussian in both side channel and
crofludic device at 20 μl/min. We demonstrated that the cells middle channel with the peaks in the range 7–9 μm and 9–
in the middle and side channels maintained viability dur- 11 μm respectively, indicating that the separation by size
occurred.
S. K. Murthy · P. Sethu · M. Toner
Surgical Services and Center for Engineering in Medicine,
Massachusetts General Hospital; Harvard Medical School; and Introduction
Shriners Hospital for Children, Boston, MA, 02114, USA
Native myocardium (cardiac muscle) is a highly dif-
G. Vunjak-Novakovic · M. Toner · M. Radisic
ferentiated tissue composed of cardiac myocytes and
Harvard-MIT Division of Health Sciences and Technology,
Massachusetts Institute of Technology, Cambridge, MA, 02139, fibroblasts with a dense supporting vasculature, collagen-
USA based extracellular matrix, and an average cell density of
1–10 · 108 cells/cm3 . The myocytes form a three-dimensional
M. Radisic ( )
syncytium that enables propagation of electrical signals
Institute of Biomaterials and Biomedical Engineering;
Department of Chemical Engineering and Applied Chemistry, across specialized intracellular junctions to produce coor-
University of Toronto, 164 College St. RS 407, dinated mechanical contractions that pump blood forward.
Toronto, ON, M5S 3G9, Canada Only 20–40% of the cells in the heart are cardiac myocytes,
e-mail: milica@chem-eng.utoronto.ca
but they occupy 80–90% of the heart volume (Nag, 1980).
S.K. Murthy Cardiac fibroblasts contribute to most of the non-myocytes
Present address: in the myocardium. The main roles of cardiac fibroblasts
Department of Chemical Engineering, Northeastern University are to secrete the components of the extra-cellular matrix
(ECM) and transmit mechanical force by the receptor
G. Vunjak-Novakovic
Present address: mediated connections to the ECM (Sussman, 2002). The
Department of Biomedical Engineering, Columbia University myocardial ECM consists of a fibrillar collagen network,
Springer
2. 232 Biomed Microdevices (2006) 8:231–237
with predominant collagen type I and III, a basement mem- separation. Hence this approach can be used to isolate stem
brane, proteoglycans, glycosaminoglycans and a variety of cells and other rare cells that do not express known markers.
other bioactive molecules (Burlew and Weber, 2002). The Furthermore, the size-based approach is the least invasive
exact composition of the ECM is regulated by a cross-talk among the state-of-the-art separation technologies because
between myocytes and fibroblasts (Sussman, 2002). Recent it does not require any chemical or biological interactions
studies demonstrated that cardiac fibroblasts propagate between the cells and the device. This is in contrast to the
electrical stimuli over the distances on the order of 100 μm majority of cell separation techniques which require antibody
via gap junction communications (Gaudesius, 2003). tags and/or centrifugation.
Endothelial cells line blood vessels of the dense myocardial This paper describes the use of a microfluidic device de-
vasculature and engage in a cross-talk with cardiomyocytes signed as a diffusive filter for cell enrichment. The device
via numerous secreted factors (Parratt, 1997; Shah, 1997). consists of a main channel that runs along its length, linked
In addition, recent evidence suggest that myocardium may to a side channel by microsieves. The side channel has a
have resident cardiac progenitor cells (e.g. isl1+, (Laugwitz, flared geometry to ensure uniform pressure gradients across
2005)) that are present at a very low frequency (∼100/109 ). all of the sieve elements. The focus of the present work was
Conventional methods for separation of cardiac cell types the isolation of the smaller, non-myocyte cells from the het-
rely on differential adhesion properties. Pre-plating (Wang, erogenous cardiac cell suspension. These cells were recov-
2004) is a method commonly used to remove fibroblast from ered through the side channel with retention of viability. Cell
cell suspension. Briefly, the cell suspension is plated in a tis- suspensions from both the middle and side channels retained
sue culture plate for a period of 15–75 min and fibroblasts the ability to attach, remain functional and express respective
are removed by fast and preferential attachment to the tissue myocyte and non-myocyte markers.
culture plastics. It was reported recently, that isl1+ cells can
be found in the pre-plates. The unattached cell suspension
is thus enriched for cardiomyocytes and endothelial cells. A Experimental section
potential drawback of the pre-plating procedure, is that 3–7
days of proliferation are usually required for non-myocytes Cell isolation
to overgrow cardiomyocytes in order to obtain cultures with
high fraction of non-myocytes. During that period gene ex- Cells were obtained from 1–2 day old neonatal Sprague
pression may change. Dawley (Charles River) rats according to procedures ap-
A heterogeneous cell population that potentially contains proved by the Institute’s Committee on Animal Care, as pre-
unique and rare cells (e.g. cardiac progenitors) necessitates viously described (Carrier, 1999). In brief, ventricles were
the need to develop new methods for cell separation. An quartered, incubated overnight at 4◦ C in a 0.06% (w/v) so-
ideal cell separation device should ensure that cell function- lution of trypsin in Hank’s Balanced Salt Solution (HBSS,
ality and viability is maintained upon the separation process Gibco), and subjected to a series of digestions (3 min, 37◦ C,
(if further cell culture is desired), should be non-invasive and 150 rpm) in 0.1% (w/v) solution of collagenase type II in
should not affect cell phenotype and gene expression espe- HBSS. The cell suspension from the digestions were col-
cially if further analysis is required. In addition the separation lected, centrifuged (750 rpm, 5 min), and the pellet was resus-
process should be fast and the device should be easy to use. pended in Dulbecco’s Modified Eagle’s Medium (DMEM,
The purpose of this work was to explore the feasibility of Gibco) containing 4.5 g/L glucose supplemented with 10%
utilization of a microfluidic device to separate cardiac cell FBS, 10 mM HEPES, 2 mM L-glutamine and 100 units/ml
subpopulations based on cell size. Microfluidic separation penicillin. The cells from the pellet were pre-plated in T75
system is of particular interest as it is single-step, requires no flasks for one 75 min period to enrich for cardiomyocytes
pre-processing incubation steps, and can potentially be inte- as described (Radisic, 2004). Cells that remained unattached
grated with analysis systems (e.g. PCR, microfluidic FACS). were used in microfluidic experiments.
Several novel size-based separation processes are being em-
ployed in the micro-scale devices (Cho, 2003; Huang, 2004; Microfluidic device fabrication
Radisic, 2006, Shevkoplyas, 2005). These devices are com-
pact, simple, and typically do not require much additional ex- Microfluidic devices were designed and fabricated at the
ternal equipment. Furthermore, they are extremely effective BioMEMS Resource Center (Massachusetts General Hos-
for low throughput small-scale applications. In most cases, pital) as described previously (Murthy, 2004; Sethu, 2006).
the devices force the fluid with a heterogeneous particle popu- Briefly, a silicon wafer was spin-coated with SU-8 (Mi-
lation through a series of channels or obstacles of varied size. croChem, Newton, MA) photoresist. Masks for two layers
The main advantage of the size-based approach is that it does comprising the device were drawn using AutoCAD software
not require the presence of cell specific markers to achieve and printed with high resolution onto a transparency (CAD
Springer
3. Biomed Microdevices (2006) 8:231–237 233
Fig. 1 Experimental set-up. (A) Eight devices run in parallel during a cell separation process. (B) Photomicrograph of the device before cell
separation. (C) Schematics of the device
Art Inc., Poway, CA). Negative replicas of the microfluidic 106 cells/mL and then flowed into the microfluidic devices at
channel structure were created by laying the masks over the a flow rate of 20 μL/min using Harvard Apparatus PHD 2000
silicon wafer and exposing to 365 nm, 11 mW/cm2 UV light syringe pump (Holliston, MA) over a time span of 50 min.
using a mask aligner (Q2001, Quintel Co., San Jose, CA), Output from the two side channels was collected separately
and removing unexposed photoresist with SU-8 developer. and combined prior to analysis. Total of 12 devices was used
Silicone elastomer [poly(dimethylsiloxane), PDMS] and cur- in 3 independent experiments
ing agent (10:1 ratio) were then poured on top of the wafers
and allowed to cure at 60◦ C for 12 h. Inlet and outlet holes Device output analysis
were punched on the PDMS replicas using a 22-gauge nee-
dle. The replicas were then bonded irreversibly to stan- At the end of separation the cells suspension was collected
dard glass slides following exposure to an oxygen plasma from the reservoir syringes, middle and side channel and an-
(Fig. 1). Prior to experiments, Tygon tubing (Small Parts alyzed for cell concentration, viability, size distribution and
Inc., Miami Lakes, FL) was press fitted into the inlet and fraction of myocytes. In addition, the cells were plated to
outlet holes on the PDMS. asses the ability to attach, proliferate and differentiate fol-
lowing the microfluidic separation.
Flow experiments Concentration and viability data were obtained using a
hemacytometer (Fisher Scientific, Fair Lawn, NJ). For vi-
Suspensions of neonatal rat heart cells were diluted with ability measurements, cells were stained with Trypan Blue
culture medium to a concentration of approximately 1.6 × (Sigma Aldrich, Milwaukee, WI) in a 1:1 ratio by volume.
Springer
4. 234 Biomed Microdevices (2006) 8:231–237
Hemacytometry images were captured at 200× in triplicates PBS containing 0.5% Tween 20 and 1.5% horse serum. The
for each device and each group using a CCD camera mounted sections were counterstained with DAPI and coverslipped
on an inverted microscope (Nikon Kohden) and imaging soft- (Vectorshield mounting medium with DAPI) and imaged us-
ware (Scion Image, Scion Corporation, Frederick, MD). For ing an inverted microscope (Axioplan, Zeiss).
cell size distribution the area of each particle in each image
was determined by thresholding using Scion Image. Subse- Contractile response
quently, the effective diameter was calculated assuming that
the particles had circular shape and knowing the area of each Following the 48 h of cultivation the chamber slides were
particle. placed in between two parallel electrodes (carbon rod)
Percentage of cardiomyocytes in the reservoir syringes spaced 1 cm apart and connected to the cardiac stimulator
and middle and side channel output was determined by fluo- (Nikon-Kohden). Cardiomyocytes were paced using square
rescence activated cell sorting (FACS). The cells were fixed pulses 2 ms in duration. The stimulating voltage was varied to
and permeabilized with the solution of acetone and methanol determine excitation threshold (minimum voltage necessary
(3:2) at −20◦ C at the concentration of 106 cells/ml. To iden- to induce synchronous contractions) and maximum capture
tify cardiomyocytes the cells were pelleted by centrifugation rate (Radisic, 2004) as described. Please refer to the videos
(100 rpm for 10 min) and resuspended in a 5% solution of in Supplemental Information.
FBS in Phosphate Buffered Saline (PBS) (106 cells/ml). The
cells were incubated with anti-troponin I (1:200, Rabbit Poly- Statisitcal analysis
clonal anti-troponin I, Chemicon) for 1 h on ice, rinsed and
incubated with fluorescein conjugated goat anti-rabbit IgG Statistical significance in pariwise comparisons was deter-
for additional 30 min on ice (1:200, Vector Laboratories). mined by Tukey’s test in conjuction with one-way ANOVA
The fluorescence was read on FACScan (Becton Dickinson). using SigmaStat 3.0. p < 0.05 was considered significant.
Unlabeled cells and cells labeled with secondary antibody
only served as controls. The number of independent samples Results and discussion
analyized was 6 for the reservoir, 5 for middle channel output
and 5 for the side channel output. The microfluidic device used in this work is a modified ver-
sion of that originally designed by Sethu et al (Sethu, 2006)
Cell culture for the separation of red blood cells and white blood cells. A
schematic diagram of the device is shown in Fig. 1. The de-
At the end of microfludic sorting cell fractions from the reser- vice consists of a main middle channel (which is 50 μm wide,
voir syringes, side and middle channels were plated into one- 200 μm tall, and 4 cm long) which is connected to adjacent
well chamber slides using 1 ml of culture medium. To deter- side channels by microsieves, which are 80 μm wide, 5 μm
mine if the ability to attach and contract (for cardiomyocytes) tall and 40 μm in length. The side channels increase in width
was maintained after microfludic sorting, the cells were cul- in a flared shape along the length of the device to ensure that
tivated for 48 h in a humidified 37◦ C/5%CO2 incubator. Cell the pressure gradient across all of the sieves in the device is
attachment and development of contractile response was ob- the same. In the absence of such a flared geometry (i.e. if the
served using an inverted microscope. side channels were simply parallel to the middle channel),
the volumetric flow rate through an individual sieve would
Expression of myocyte and non-myocyte markers drop linearly as a function of the sieve’s position along the
length of the device. This would result in crowding of cells
After 48 h of cultivation the cells were fixed overnight us- in the vicinity of the device inlet and consequent clogging of
ing 10% neutral buffered formaline and stained for phe- sieves and significant cell deformation. The model developed
notypic markers: cardiac troponin-I for myoyctes and vi- by (Sethu, 2006) approximates the side channel as a series
mentin for non-myocytes. For double staining, the slides of rectangular blocks of increasing widths, with the width of
were blocked with 10% horse serum (Vector Laboratories) each block, wside , given by:
and incubated with the solution containing polyclonal rab-
m.wmiddle
bit troponin I (Chemicon 1:200) and mouse anti-vimentin wside = (1)
Cy3 conjugated (clone V9, Sigma, 1:100). Subsequently, R − (n − m)
the slides were rinsed in PBS and incubated for 30 min where m is the sieve position, n the total number of sieves, and
at 37◦ C with fluorescein conjugated goat anti-rabbit IgG wmiddle the width of the middle channel. R is a dimensionless
(1:200, Vector laboratories) for TnI visualization as described number defined as X/2Y where X is the volumetric flow rate
(Radisic, 2004) and fluorescein conjugated horse anti-mouse of fluid exiting the device through the middle channel and Y
IgG (1:200) for 30 min at 37◦ C. All antibodies were diluted in the flow rate of fluid coming out of each side channel. This
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5. Biomed Microdevices (2006) 8:231–237 235
Fig. 2 Percentage of cardiomyocytes and cell viability in the reservoir, myocytes. (B) Viability of cell suspension in reservoir, middle and
middle and side channels. (A) Average percentage of cardiomyocytes side channels at the end of separation as determined by Trypan blue
as determined by FACS on cells fixed immediately after separation exclusion. No significant difference among the groups (P = 0.22) as
and stained for cardiac troponin I (avg ±SD) N = 6, middle n = 5 determined by one-way ANOVA on ranks in conjunction with Tukey
side n = 5. Statistics: Tukey test with one way ANOVA, p < 0.05 test
considered significant. Side channel is significantly enriched for non-
empirical model was tested using finite element simulations to pass through the sieve. Large cells (over 15 μm) most
by (Sethu, 2006), and was determined to be an improvement likely remained in the device since cell adhesion at the de-
over the linear side channel geometry. vice wall was observed at the end of the separation process
For the present study, multiple devices were run in par- (Fig. 1(D)). Since the large cells are in most cases myocytes
allel (Fig. 1 shows an experiment with eight devices). The or non-viable cells, the cell adhesion was not a problem in
viability of the heart cells was maintained during the 50 min this application which focused on the collection of small non-
separation process (Fig. 2(B)), most likely due to the pres- myocytes in the side channels. Future studies will examine
ence of culture medium flow, that maintained oxygen sup- the enrichment of the larger cell subpopulations, with a dif-
ply, and low shear stress (1 dyn/cm2 along the walls of ferent sieve design and poly (ethylene glycol) to prevent cell
the microsieves) within the microfludic device prevented adhesion within the device.
cell damage. When exposed to shear stress cardiac my- Fluorescence activated cell sorting (FACS) confirmed the
ocytes round up and show signs of dedifferentiation (Carrier, enrichment of the side channel output for non-myocytes
2002; Carrier, 2002; Kretzmer and Schugerl, 1991; Smith, (Fig. 2(A)). While the reservoir and middle channel output
1987; Stathopoulos and Hellums, 1985) as documented in contained ∼60% of cardiac myocytes as identified by cardiac
our previous work involving perfusion of cardiomyocytes Troponin I immunoflorescence, only 13% of the cells in the
on porous collagen sponges (Radisic, 2004). Hence main- side channel were troponin I positive.
taining shear stress below 1 dyn/cm2 is critical in the mi- In order to confirm that the cells maintained ability to
crofluidic separation of heart cells. All groups (reservoir, attach and function after microfluidic fractionation, we
middle and side channel) had comparable and high via- plated the middle and side channel output and cultivated
bility in the range 70–80% (Fig. 2(B)). This value was them for 48 h. The cells from the reservoir were used as a
comparable to the viability of the freshly isolated cell sus- control. Since non-myocytes tend to overgrow in culture, the
pension that we demonstrated previously to be 84 ± 2% cultivation time was sufficiently short to allow identification
(Radisic, 2004). The cell concentration in the side chan- of contractile response but prevent any significant changes
nel output was 0.24 ± 0.20 106 cells/ml while the mid- in the myocyte/non-myocyte ratio. Cells attached to the
dle channel output had cell concentration of 2.11 ± 0.15 chamber slides in all groups. To identify cell subpopulations
106 cells/ml. the cultures were double stained for cardiac troponin I
Cell size distribution indicated that the initial cell popu- (green) and vimentin (red) (Fig. 4). Troponin I is a part
lation (in the reservoir) was bimodal with two peaks in the of contractile apparatus and thus it is found only in the
range 7–9 μm and 15–17 μm (Fig. 3(A)). Following the mi- functional cardiac mycoytes. Vimentin is the intermediate
crofluidic fractionation, the side channel output was signif- filament found in non-myocytes. Reservoir and side channel
icantly enriched for the cells in the range of 7–9 μm (over contained the mixture of cardiomycoytes and non-myocytes.
50% of cells). (Fig. 3(C)). The middle channel output exhib- Cardiomyocytes were large and contained well developed
ited a Gaussian size distribution with the peak in the range contractile apparatus (Fig. 4(B) arrows). In contrast, side
9–11 μm. Comparing this range with the height of the mi- channel contained mostly non-mycoytes that spread during
crosieves (5 μm) indicates that cells had to deform in order the culture (Fig. 4(C)). Occasional myocytes were small
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6. 236 Biomed Microdevices (2006) 8:231–237
Fig. 3 Size distribution for cells in the (A) reservoir, (B) middle and Fig. 4 Immunofluorescent staining for cardiac troponin I (green) and
(C) side channels after separation in the microfluidic device. Effective vimentin (red) of the neonatal rat heart cells separated in the microfluidic
cell diameter plotted on x-axis [mm]. In (B) ∗ indicates significantly device. Following the spearation the cells were plated into chamber
less than for 9–11 μm, in (C) ∗ indicates significantly less than for slides and cultivated for 48 h. (200×) (A) Reservior, (B) Middle channel
7–9 μm. Statistics: Tukey test with one way ANOVA, p < 0.05 con- output, arrows indicate well developed contractile apparatus, (C) Side
sidered significant channel output
and compact with poorly developed contractile apparatus
(Fig. 4(C) inset). fully developed cells. In addition, the cells from the mid-
After 48 h in culture, spontaneous contractions were dle channel retained the ability to respond to cardiac-like
present in the cardiomyocytes from the middle channel out- electric stimuli. Cells from the middle channel were paced
put and the reservoir cells used as a control, thus indicating up to 160 bpm at the excitation threshold of 9.0 V/cm. The
that the cells remain functional after microfluidic sorting. control reservoir cells, had the same excitation threshold
Occasional myocytes in the side channel did not exhibit any (9.0 V/cm) but exhibited slightly higher maximum capture
contractile activity, indicating that this may be early and not rate of 220 bpm.
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7. Biomed Microdevices (2006) 8:231–237 237
Conclusions R.L. Carrier, M. Rupnick, R. Langer, F.J. Schoen, L.E. Freed, and G.
Vunjak-Novakovic, Tissue Engineering 8, 175 (2002).
R.L. Carrier, M. Rupnick, R. Langer, F.J. Schoen, L.E. Freed, and G.
We demonstrated the feasibility of utilizing a sieve-like
Vunjak-Novakovic, Biotechnology and Bioengineering 78, 617
microfluidic device to separate enriched subpopulations of (2002).
neonatal rat heart cells, myocytes and non-myocyte, on the B.S. Cho, T.G. Schuster, X.Y. Zhu, D. Chang, G.D. Smith, and S.
basis of size. Cell viability was maintained during the separa- Takayama, Analytical Chemistry, 75, 1671 (Apr 1, 2003).
G. Gaudesius, M. Miragoli, S.P. Thomas, and S. Rohr, Circulation Re-
tion procedure. Side channel was enriched for non-mycoytes.
search 93, 421 (Sep 5, 2003).
Following the separation procedure the cells from side and L.R. Huang, E.C. Cox, R.H. Austin, and J.C. Sturm, Science 304, 987
middle channel output retained the ability to attach and ex- (May 14, 2004).
press cell-specific markers (tropnin-I or vimentin). The car- G. Kretzmer and K. Schugerl, Applied Microbiology and Biotechnol-
ogy 34, 613 (1991).
diomyocytes from the middle channel output were functional
K.L. Laugwitz, A. Moretti, J. Lam, P. Gruber, Y. Chen, S. Woodard,
as indicated by the presence of spontaneous and stimulated L.Z. Lin, C.L. Cai, M.M. Lu, M. Reth, O. Platoshyn, J.X. Yuan,
contractile activity. This approach may be useful in separat- S. Evans, and K.R. Chien, Nature 433, 647 (Feb 10, 2005).
ing small non-myocyte cells from the heterogenous heart cell S.K. Murthy, A. Sin, R.G. Tompkins, and M. Toner, Langmuir 20, 11649
(Dec 21, 2004).
preparations. In future work, the modifications to consider
A.C. Nag, Cytobios 28, 41 (1980).
would involve coating of the device with PEG to prevent cell J.R. Parratt, A.Vegh, I.J. Zeitlin, M. Ahmad, K. Oldroyd, K. Kaszala,
adhesion and optimization of the device operation in terms of and J.G. Papp, American Journal of Cardiology 80, 124A
flow rate and sieve size, as well as characterization of specific (1997).
M. Radisic, R.K. Iyer, and S.K. Murthy, International Journal of
non-myocyte cell populations (e.g. endothelial cells, smooth
Nanomedicine, 1, 3 (2006).
muscle cells and isl1+ cells) in the device output. M. Radisic, H. Park, H. Shing, T. Consi, F.J. Schoen, R. Langer, L.E.
Freed, and G. Vunjak-Novakovic, Proceedings of the National
Academy of Sciences of the United States of America 101, 18129
(Dec 28, 2004).
Acknowledgments
M. Radisic, L. Yang, J. Boublik, R.J. Cohen, R. Langer, L.E. Freed, and
G. Vunjak-Novakovic, American Journal of Physiology: Heart and
We gratefully acknowledge the support of the National Insti- Circulatory Physiology 286, H507 (2004).
tutes of Health Grant Nos. P41 EB02503 (BioMEMS Re- P. Sethu, A. Sin, and M. Toner, Lab on a Chip 6, 83, (2006).
A.M. Shah, A. Mebazaa, Z.K. Yang, G. Cuda, E.B. Lankford, C.B.
source Center; Toner) and P41 EB002520–01A1, (Tissue
Pepper, S.J. Sollott, J.R. Sellers, J.L. Robotham, and E.G. Lakatta,
Engineering Resource Center; Vunjak-Novakovic) RO1 HL Circulation Research 80, 688 (1997).
076485 (Vunjak-Novakovic and Radisic), and Sasha Kuchar- S.S. Shevkoplyas, T. Yoshida, L.L. Munn, and M.W. Bitensky, Analyt-
czyk for help with particle size distribution analysis. ical Chemistry 77, 933 (Feb 1, 2005).
C.G. Smith, P.F. Greenfield, and D. Randerson, in Modern approaches to
animal cell technology R.E. Spier, J.B. Griffith, Eds. (Butterworth,
Kent, UK, 1987).
References N.A. Stathopoulos and J.D. Hellums, Biotechnology and Bioengineer-
ing 27, 1021 (1985).
B.S. Burlew and K.T. Weber Herz, 27, 92 (Mar, 2002). M.A. Sussman, A. McCulloch, and T.K. Borg, Circulation Research 91,
R.L. Carrier, M. Papadaki, M. Rupnick, F.J. Schoen, N. Bursac, R. 888 (Nov 15, 2002).
Langer, L.E. Freed, and G. Vunjak-Novakovic, Biotechnology and J.X. Wang, J. Fan, F. Cheung, C. Laschinger, A. Seth, and C. McCulloch,
Bioengineering 64, 580 (1999). Faseb Journal 18, C39 (May 14, 2004).
Springer