Application Of Adult Stem Cells Research Articles

Adult stem cells in the eye: Identification, characterisation, and therapeutic application in ocular regeneration - A review.

Adult stem cells, present in various parts of the human body, are undifferentiated cells that can proliferate and differentiate to replace dying cells within tissues. Stem cells have specifically been identified in the cornea, trabecular meshwork, crystalline lens, iris, ciliary body, retina, choroid, sclera, conjunctiva, eyelid, lacrimal gland, and orbital fat. The identification of ocular stem cells broadens the potential therapeutic strategies for untreatable eye diseases. Currently, stem cell transplantation for corneal and conjunctival diseases remains the most common stem cell-based therapy in ocular clinical management. Lens epithelial stem cells have been applied in the treatment of paediatric cataracts. Several early-phase clinical trials for corneal and retinal regeneration using ocular stem cells are also underway. Extensive preclinical studies using ocular stem cells have been conducted, showing encouraging outcomes. Ocular stem cells currently demonstrate great promise in potential treatments of eye diseases. In this review, we focus on the identification, characterisation, and therapeutic application of adult stem cells in the eye.

Bioactivity of human adult stem cells and functional relevance of stem cell-derived extracellular matrix in chondrogenesis

BackgroundAutologous chondrocyte implantation (ACI) has been used to treat articular cartilage defects for over two decades. Adult stem cells have been proposed as a solution to inadequate donor cell numbers often encountered in ACI. Multipotent stem/progenitor cells isolated from adipose, bone marrow, and cartilage are the most promising cell therapy candidates. However, different essential growth factors are required to induce these tissue-specific stem cells to initiate chondrogenic differentiation and subsequent deposition of extracellular matrix (ECM) to form cartilage-like tissue. Upon transplantation into cartilage defects in vivo, the levels of growth factors in the host tissue are likely to be inadequate to support chondrogenesis of these cells in situ. The contribution of stem/progenitor cells to cartilage repair and the quality of ECM produced by the implanted cells required for cartilage repair remain largely unknown. Here, we evaluated the bioactivity and chondrogenic induction ability of the ECM produced by different adult stem cells.MethodsAdult stem/progenitor cells were isolated from human adipose (hADSCs), bone marrow (hBMSCs), and articular cartilage (hCDPCs) and cultured for 14 days in monolayer in mesenchymal stromal cell (MSC)–ECM induction medium to allow matrix deposition and cell sheet formation. The cell sheets were then decellularized, and the protein composition of the decellularized ECM (dECM) was analyzed by BCA assay, SDS-PAGE, and immunoblotting for fibronectin (FN), collagen types I (COL1) and III (COL3). The chondrogenic induction ability of the dECM was examined by seeding undifferentiated hBMSCs onto the respective freeze-dried solid dECM followed by culturing in serum-free medium for 7 days. The expression levels of chondrogenic genes SOX9, COL2, AGN, and CD44 were analyzed by q-PCR.ResultshADSCs, hBMSCs, and hCDPCs generated different ECM protein profiles and exhibited significantly different chondrogenic effects. hADSCs produced 20–60% more proteins than hBMSCs and hCDPCs and showed a fibrillar-like ECM pattern (FNhigh, COL1high). hCDPCs produced more COL3 and deposited less FN and COL1 than the other cell types. The dECM derived from hBMSCs and hCDPCs induced spontaneous chondrogenic gene expression in hBMSCs.ConclusionsThese findings provide new insights on application of adult stem cells and stem cell-derived ECM to enhance cartilage regeneration.

Correlates of protection for SARS-CoV-2 vaccines

<div class="authors authors-lg"><div class="author"><div class="author-img"><img src="https://bioinsightscdn.blob.core.windows.net/uploads/Bunnell 200x200.png" data-image="1"></div><div class="author-det"> <b>Bruce A Bunnell </b>is a professor and Chair of the Department of Microbiology, Immunology and Genetics at the University of North Texas Health Science Center in Fort Worth, TX. Previously, he served as Director of the Tulane Center for Stem Cell Research and Regenerative Medicine and Professor in the Department of Pharmacology in the Tulane University School of Medicine. Dr. Bunnell obtained his PhD in Microbiology from the University of Alabama at Birmingham School of Medicine. He then pursued Postdoctoral Fellowship research at the Howard Hughes Medical Institute in the School of Medicine at the University of Michigan and the National Human Genome Research Institute at the National Institutes of Health in Bethesda, MD. Dr. Bunnell was an Assistant Professor at the Nationwide Children’s Hospital Research Institute, part of the Ohio State University School of Medicine prior to joining the faculty at Tulane University in 2002. Dr. Bunnell’s research program is focused on both the basic science and translational applications of adult stem cells isolated from the bone marrow and adipose tissue. Dr. Bunnell investigates use of mesenchymal stem cells (MSCs) isolated from the bone marrow or adipose tissue as a therapeutic intervention for both multiple sclerosis (MS) wound repair, lung injury and bone repair. He is particularly interested the interactions of MSC with the immune system and how the cells elicit robust anti-inflammatory effects in vivo. He is currently working towards a human clinical trials for the treatment of osteoarthritis, traumatic brain injury and MS with these cells. He has served as a reviewer of stem cell, regenerative medicine and tissue engineering grants for the National Institutes of Health, Department of Defense and several state funded programs including Maryland, New York, Virginia and Pennsylvania. He has also served on grant review panels for several foreign countries including Denmark, Ireland, Poland, Germany and Spain. Dr. Bunnell serves as an Editorial Board Member for several journals, including Stem Cells, BMC Genomics, and Regenerative Medicine. </div></div></div>

Expression of reprogramming factors in mesenchymal stem cells isolated from equine umbilical cord Wharton’s jelly and amniotic fluid

Stem cells represent the most promising population for regenerative cell therapy and have gained much attention during the recent past. Mesenchymal stem cells (MSCs) are multipotent stem cells that can differentiate into trilineages. Like haematopoietic cells, mesenchymal cells have been shown to proliferate and form fibroblast-like colonies in vitro. Despite major progress in our general knowledge related to the application of adult stem cells, finding alternative sources for bone marrow MSCs has remained a challenge. A wide diversity of isolation procedures for mesenchymal stromal cells from various tissues of the placenta, umbilical cord and Wharton's jelly have been described for humans and other species. In this study, we isolated established umbilical cord Wharton’s jelly as a primary source for isolation of mesenchymal stem cells since it is a rich source of stem cells and no ethical concerns are involved. Equine umbilical cord Wharton’s jelly segments were collected during foaling time and digested enzymatically and cultured in-vitro in culture medium. In addition to the study of their morphology and colony forming units, the expression of reprogramming factors by the isolated MSCs were also studied. The isolated MSCs were observed to be plastic adherent, clonogenic and their morphology were polygonal, star shaped and fibroblast like. They revealed a strong expression of pluripotent stemness markers OCT-4, SOX-2, Nanog and KLF-4. From the current study, it can be concluded that Wharton's jelly is a rich source of stem cells with stemness properties expressing the reprogramming factors and mesenchymal like morphology and could be used as an alternate for the bone marrow derived mesenchymal stem cells for cell based regenerative therapies.

Learning lessons from the long, troubled history of stem cell therapy for future clinical success

<div class="authors authors-lg"><div class="author"><div class="author-img"><img src="https://cdn.insights.bio/uploads/Rasko copy.jpg" data-image="1"></div><div class="author-det"> <b>John EJ Rasko</b> is an Australian pioneer in the application of adult stem cells and genetic therapy. Since 1999 he has directed the Department of Cell and Molecular Therapies at Royal Prince Alfred Hospital and the Gene and Stem Cell Therapy Program at the Centenary Institute, University of Sydney. John Rasko is a clinical hematologist, pathologist and scientist with an international reputation in gene and stem cell therapy, experimental hematology and molecular biology. In over 200 publications he has contributed to the understanding of stem cells and blood cell development, gene therapy technologies, cancer causation and treatment, human genetic diseases and molecular biology. He serves on Hospital, state and national bodies including Chair of GTTAC, Office of the Gene Technology Regulator – responsible for regulating all genetically-modified organisms in Australia – and immediate past Chair of the Advisory Committee on Biologicals, Therapeutic Goods Administration. Contributions to scientific organizations include co-founding (2000) and past-President (2003–5) of the Australasian Gene &amp; Cell Therapy Society; President (2018–20), President-Elect (2016–18) and Vice President (2008–12) of the International Society for Cell &amp; Gene Therapy; Scientific Advisory Committees and Board member for philanthropic foundations; and several Human Research Ethics Committees. He is a founding Fellow of the Australian Academy of Health and Medical Sciences. In 2018, the Board of the ABC honored him as the sixtieth Boyer Lecturer. He is the recipient of national (RCPA, RACP, ASBMB) and international awards in recognition of his commitment to excellence in medical research, including appointment as an Officer of the Order of Australia. </div></div></div>

Understanding the "SMART" features of hematopoietic stem cells and beyond.

Since the huge success of bone marrow transplantation technology in clinical practice, hematopoietic stem cells (HSCs) have become the gold standard for defining the properties of adult stem cells (ASCs). Here, we describe the “self-renewal, multi-lineage differentiation, apoptosis, rest, and trafficking” or “SMART” model, which has been developed based on data derived from studies of HSCs as the most well-characterized stem cell type. Given the potential therapeutic applications of ASCs, we delineate the key characteristics of HSCs using this model and speculate on the physiological relevance of stem cells identified in other tissues. Great strides are being made in understanding the biology of ASCs, and efforts are now underway to develop safe and effective ASC-based therapies in this emerging area.

Effects of the histone acetylase inhibitor C646 on growth and differentiation of adipose-derived stem cells

ABSTRACT As an important histone acetylase, the transcriptional coactivator P300/CBP affects target gene expression and plays a role in the maintenance of stem cell characteristics and differentiation potential. In this study, we explored the action of a highly effective selective histone acetylase inhibitor, C646, on goat adipose-derived stem cells (gADSCs), and investigated the impact of histone acetylation on the growth characteristics and the differentiation potential of ADSCs. We found that C646 blocked the cell proliferation, arrested the cell cycle, and triggered apoptosis. Notably, immunocytochemistry and western blot analyses showed that the acetylation level of histone H3K9 was increased. Moreover, although real-time quantitative PCR and western blot confirmed that P300 expression was inhibited under these conditions, the expression level of two other histone acetylases, TIP60 and PCAF, was significantly increased. Furthermore, C646 clearly promoted the differentiation of gADSCs into adipocytes and had an impact on their differentiation into neuronal cells. This study provides new insights into the epigenetic regulation of stem cell differentiation and may represent an experimental basis for the comprehension of stem cell characteristics and function. Furthermore, it is of great relevance for the application of adult stem cells to somatic cell cloning, which may improve the efficiency of large livestock cloning and foster the production of transgenic animals.

Simulated Microgravity Affects Numb Localization in Human Adipose-Derived Stem Cells

An ultimate goal of human space exploration is to travel to Mars and beyond in search of scientific knowledge. However, a current problem in space exploration is that astronauts tend to develop osteoporosis or loss of bone mass. To recover bone mass, some tissue engineering applications use adult stem cells. Adult stem cells are known to asymmetrically divide into specialized cells like bone, muscles, cartilage, etc. However, our own results indicated that stem-cells exposed to simulated microgravity did not differentiate into specialized cells. It is not known why stem cells demonstrated inhibited differentiation on microgravity. We decided to study Numb, a cell fate determinant protein involved in osteogenesis. Numb promotes differentiation by inhibiting the Notch signaling pathway through localization changes in asymmetric stem cell division. We hypothesized that Numb localization is affected under microgravity. We approached this by plating human adipose-derived stem cells under standard gravity and simulated microgravity. We used our own ground-based simulated microgravity device based on lab-on-a-chip and clinorotation technology, as previously published. Cells were stained using immunofluorescence for intracellular Numb and imaged in a fluorescence microscope. Our results showed highly localized Numb in elongated cells in standard gravity. In contrast, Numb was not specifically localized for cells in microgravity independently of morphology. Our next step was to explore how to control Numb localization to increase differentiation. We used a micropattern method that allowed us to force the cells to take on specific shapes like squares, triangles, and circles. By controlling cell-substrate adhesion, we found that we were able to increase Numb localization. The potential applications of adult stem cells in microgravity may be inhibited due to the lack of numb localization, but we have shown that this can be reversed using techniques such as micropatterning.

Stem cells and tooth regeneration: prospects for personalized dentistry.

Over the last several decades, a wealth of information has become available regarding various sources of stem cells and their potential use for regenerative purposes. Given the intense debate regarding embryonic stem cells, much of the focus has centered around application of adult stem cells for regenerative engineering along with other relevant aspects including use of growth factors and scaffolding materials. The more recent discovery of tooth-derived stem cells has sparked much interest in their application to regenerative dentistry to treat and alleviate the most prevalent oral diseases-i.e., dental caries and periodontal diseases. Also exciting is the advent of induced pluripotent stem cells, which provides the means of using patient-derived somatic cells for their creation, and their eventual application for generation of the dental complex. Thus, evolving developments in the field of regenerative dentistry indicate the prospect of constructing "custom-made" tooth and supporting structures thereby fostering the realization of "personalized dentistry." On the other hand, others have explored the possibility of augmenting endogenous regenerative capacity through utilization of small molecules to regulate molecular signaling mechanisms that mediate regeneration of tooth structure. This review is focused on these aspects of regenerative dentistry in view of their relevance to personalized dentistry.

Isolation and culture of putative mesenchymal stem cells from equine umbilical cord Wharton’s jelly

Despite major progress and knowledge related to the application of adult stem cells, finding alternative sources for bone marrow MSCs has remained a challenge in both humans and animals. In the current study, two protocols namely sequential enzymatic tissue digestion and tissue explant techniques were tried for successful establishment of MSC culture. Umbilical tissues were isolated each time of foaling from five sequential foalings of Marwari mares. Total cell yield, their growth potential and cryopreservation potential were studied. Adherent cell colonies could be established using both isolation methods. Both the cell populations yielded from different protocols performed similarly in terms of population doubling and CFU number value. Additionally, the cells proliferated vigourously and displayed a similar morphology of mesenchymal stem cells. The MSCs were plastic adherent, colonogenic and their morphology was polygonal and fibroblast like. During the proliferation, the cells exhibited density dependent inhibition; analysis of microbial contamination from bacteria, mycoplasma and fungi were negative; the population doubling time of the MSCs isolated was 34.8 h and 40.2 h in enzymatic treatment and tissue explant methods respectively, and diploid chromosome number of the cells was 64, and the diploid frequency was higher than 80%. In conclusion, this study reveals that both the techniques proved to be non-invasive, efficient, simple and quick for isolation and establishment of MSC culture of extra embryonic tissues from equines.

Adult Stem Cells of Orofacial Origin: Current Knowledge and Limitation and Future Trend in Regenerative Medicine.

Stem cell research is one of the most rapidly expanding field of medicine which provides significant opportunities for therapeutic and regenerative applications. Different types of stem cells have been isolated investigating their accessibility, control of the differentiation pathway and additional immunomodulatory properties. Bulk of the literature focus has been on the study and potential applications of adult stem cells (ASC) because of their low immunogenicity and reduced ethical considerations. This review paper summarizes the basic available literature on different types of ASC with special focus on stem cells from dental and orofacial origin. ASC have been isolated from different sources, however, isolation of ASC from orofacial tissues has provided a novel promising alternative. These cells offer a great potential in the future of therapeutic and regenerative medicine because of their remarkable availability at low cost while allowing minimally invasive isolation procedures. Furthermore, their immunomodulatory and anti-inflammatory potential is of particular interest. However, there are conflicting reports in the literature regarding their particular biology and full clinical potentials. Sound knowledge and higher control over proliferation and differentiation mechanisms are prerequisites for clinical applications of these cells. Therefore, further standardized basic and translational studies are required to increase the reproducibility and reduce the controversies of studies, which in turn facilitate comparison of related literature and enhance further development in the field.

Harvesting multipotent progenitor cells from a small sample of tonsillar biopsy for clinical applications

BackgroundHuman adult stem cells hold the potential for the cure of numerous conditions and degenerative diseases. They possess major advantages over pluripotent stem cells as they can be derived from donors at any age, and therefore pose no ethical concerns or risk of teratoma tumor formation in vivo. Furthermore, they have a natural ability to differentiate and secrete factors that promote tissue healing without genetic manipulation. However, at present, clinical applications of adult stem cells are limited by a shortage of a reliable, standardized, and easily accessible tissue source which does not rely on specimens discarded from unrelated surgical procedures.MethodHuman tonsil-derived mesenchymal progenitor cells (MPCs) were isolated from a small sample of tonsillar tissue (average 0.88 cm3). Our novel procedure poses a minimal mechanical and enzymatic insult to the tissue, and therefore leads to high cell viability and yield. We characterized these MPCs and demonstrated robust multipotency in vitro. We further show that these cells can be propagated and maintained in xeno-free conditions.ResultsWe have generated tonsillar biopsy-derived MPC (T-MPC) lines from multiple donors across a spectrum of age, sex, and race, and successfully expanded them in culture. We characterized them by cell surface markers, as well as in vitro expansion and differentiation potential. Our procedure provides a robust yield of tonsillar biopsy-derived T-MPCs.ConclusionsMillions of MPCs can be harvested from a sample smaller than 1 g, which can be collected from a fully awake donor in an outpatient setting without the need for general anesthesia or hospitalization. Our study identifies tonsillar biopsy as an abundant source of adult MPCs for regenerative medicine.

Lipid-mediated Wnt protein stabilization enables serum-free culture of human organ stem cells

Wnt signalling proteins are essential for culture of human organ stem cells in organoids, but most Wnt protein formulations are poorly active in serum-free media. Here we show that purified Wnt3a protein is ineffective because it rapidly loses activity in culture media due to its hydrophobic nature, and its solubilization requires a detergent, CHAPS (3-[(3-cholamidopropyl) dimethylammonio]-1-propanesulfonate), that interferes with stem cell self-renewal. By stabilizing the Wnt3a protein using phospholipids and cholesterol as carriers, we address both problems: Wnt activity remains stable in serum-free media, while non-toxic carriers allow the use of high Wnt concentrations. Stabilized Wnt3a supports strongly increased self-renewal of organ and embryonic stem cells and the serum-free establishment of human organoids from healthy and diseased intestine and liver. Moreover, the lipophilicity of Wnt3a protein greatly facilitates its purification. Our findings remove a major obstacle impeding clinical applications of adult stem cells and offer advantages for all cell culture uses of Wnt3a protein.

Therapeutic Application of Adult Stem Cells in the Heart.

Cell therapies have been explored as a potential treatment avenue to treat heart diseases, such as myocardial infarction, doxorubicin-induced cardiomyopathy, and heart failure. Embryonic and adult stem cells (ASCs) have been examined in animal and clinical settings. Unlike embryonic and induced pluripotent stem cells, ASCs do not pose a threat to form teratomas, nor do they have immune system concerns, making them ideal for therapeutic use in humans. In this review, we will investigate different characteristics and sources of adult stem cells and progenitor cells, as well as determine their efficacy in cell transplantation in experimental and clinical trials. In addition, we will propose other research avenues that may promote further understanding and use of ASCs in therapeutic designs.

A Novel Stem Cell Paradigm: Past Controversies, Present Challenges &amp; Future Prospects

Stem Cell therapeutics is a revolutionary change in the world of modern medicine. These magical bullets have evolved as alternative therapeutic modality to conventional method. Different countries have passed legislation to undertake the human embryonic stem cell research. Developed countries like USA and, Australia have banned the exploration of hESCs for research purpose. While on the other hand, developing countries have made stringent regulatory approvals and permitted the research. To avoid ethical conspiracy, induced Pluripotent stem cells with same potential with that of hESCs raised scientific breakthrough. The major flaw related to iPSCs was teratoma formation. Thus to avoid hESCs controversy and loopholes of iPSCs, application of adult stem cells came into existence. To manufacture clinical grade stem cells, cell identity, purity and genomic stability for long term culturing is to be assured. For this, various cell culture and molecular techniques are reported to assess the quality of stem cells. For sterility and safety, culture contamination, viability and presence of endotoxins/pyrogens relevant tests are noted. The autologous and allogenic criteria are discussed related to safety of cells. In nutshell, ethical concern is resolved by developing adult stem cells and quality control for dispensing cell is established by cell identity, purity, genomic stability, sterility and safety. Thus, emerging stem cells in the era of biotherapeutics harbors a promising role for incurable degenerative conditions

Expression of early transcription factors by mesenchymal stem cells derived from ovine umbilical cord Wharton’s jelly

Mesenchymal stem cells (MSCs) are multipotent stem cells that can differentiate into mesodermal lineages. Despite major progress in our general knowledge related to the application of adult stem cells, finding alternative sources for bone marrow MSCs has remained to be challenged. In this study, we utilized ovine umbilical cord Wharton’s jelly as a primary source for isolation of MSCs since it is a rich source of MSCs and no ethical issues were involved. Ovine umbilical cord Wharton’s jelly segments were digested enzymatically and cultured in vitro in culture medium. In addition to the study of their morphology and colony forming units, the expression of pluripotent stem cell markers by the isolated MSCs were also studied. The MSCs were plastic adherent, clonogenic and their morphology were polygonal, star shaped and fibroblast like. They revealed a strong expression of pluripotent stemness markers Oct4, Sox2, Nanog and Alkaline phosphatase. These cells confirmed their ability of self-renewal by expressing Sox2 gene and their properties of pluripotency and plasticity by expressing Oct4, Nanog and Alkaline phosphatase. The study revealed that Wharton’s jelly is a rich source of stem cells with stemness properties and mesenchymal like morphology and could be used as an alternate for the bone marrow derived MSCs for cell based regenerative therapies.

An Overview of Neural Differentiation Potential of Human Adipose Derived Stem Cells.

There is wide interest in application of adult stem cells due to easy to obtain with a minimal patient discomfort, capable of producing cell numbers in large quantities and their immunocompatible properties without restriction by ethical concerns. Among these stem cells, multipotent mesenchymal stem cells (MSCs) from human adipose tissue are considered as an ideal source for various regenerative medicine. In spite of mesodermal origin of human adipose-derived stem cells (hADSCs), these cells have differentiation potential toward mesodermal and non-mesodermal lineages. Up to now, several studies have shown that hADSCs can undergo transdifferentiation and produce cells outside of their lineage, especially into neural cells when they are transferred to a specific cell environment. The purpose of this literature review is to provide an overview of the existing state of knowledge of the differentiation potential of hADSCs, specifically their ability to give rise to neuronal cells. The following review discusses different protocols considered for differentiation of hADSCs to neural cells, the neural markers that are used in each procedure and possible mechanisms that are involved in this differentiation.

Application of Adult Stem Cells in Medicine.

Application of Adult Stem Cells in Medicine.

Human Platelet Lysates Promote the Differentiation Potential of Adipose-Derived Adult Stem Cell Cultures

Adipose tissue from liposuction is a rich source for human mesenchymal stem cells. This type of adult stem cell is ethically acceptable, that paved the way for research on their potential use in regenerative medicine. However, any clinical application of adult stem cells is impeded by the use of FBS as an animal-derived growth supplement. In addition, stem cell cultures gained importance as innovative human-based alternative to animal testing, in vitro toxicology, drug testing and safety assessment. Thus, animal-derived component-free culture protocols are mandatory for a successful application of human stem cell-based testing systems under humanized conditions. Recently, we succeeded in using human platelet lysates (PL) as a serum alternative in the cell culture of a number of human and animal cell lines, and human mesenchymal stem cells. PL were prepared as cell-free extracts from activated donor thrombocytes. The minimal criteria defining multipotent mesenchymal cells are (1) the capacity to adhere to plastic, (2) the expression of specific surface antigens (e.g. CD73, CD90, CD105) for undifferentiated state, and (3) the potential of the cells to differentiate into the adipogenic, chondrogenic and osteogenic lineage. In the present study, adipose-derived stem cells (ADSC) were used as cell model. ADSC were maintained under PL or FBS and then switched to the respective media to induce mesodermal differentiation. Differentiation endpoints were assessed by phase-contrast microscopy and by histochemical staining: (1) lipid droplets in adipocytes were stained by Oil red O, (2) proteoglycans in chondrogenic spheroids were detected by toluidineblue, and fine structure of spheroids was monitored by scanning electron microscopy, and (3) calcium deposits in differentiated osteoblasts were stained with silver nitrate (von Kossa staining). Adipogenic differentiation was further confirmed by quantitative real-time PCR of selected marker genes (PREF1 vs. FABP4). There were no differences between FBS- and PL-grown ADSC, indicative for retention of the differentiation potential of ADSC under animal-derived component-free culture conditions in PL-supplemented culture media. The degree of adipogenic and osteogenic differentiation was even more pronounced under PL compared to FBS. Keywords: Human adult stem cells, platelet lysates, multipotent stem cell differentiation, mesodermal lineage. Read more →

Preliminary Report of In Vitro Reconstruction of a Vascularized Tendonlike Structure

A greater supply of tendinous tissue can be obtained through tissue engineering technology with increasing application of adult stem cells. It is well known that adipose-derived stem cells (ADSCs), found in abundance in adipose tissue, have the same differentiating capacity as mesenchymal stem cells yet have the advantage of being easily isolated. In the present study, we combined the great facility of ADSCs to differentiate with the application of an external mechanical stimulus to successfully create an in vitro reconstructed tendonlike structure with a microcapillary network. Hyalonect meshes (Fidia Advanced Biopolymers, Abano Terme, Padova, Italy) were used as scaffold. Human ADSCs were seeded onto the biomaterials, and the cell/scaffold constructs were cultured under mechanical stress for up to 15 days. Human tenocytes were used in the same conditions as control. Performance was assessed by histology, immunochemistry, ultrastructure, and biomolecular analysis. Adipose-derived stem cells seeded onto Hyalonect adhered and differentiated along the entire surface of the biomaterial and began to infiltrate within its structure. Subsequently, endothelial cells migrated, forming a capillary in the new extracellular matrix. This technique allowed for the creation of a vascularized tendon equivalent that could easily be detached from the bioreactor, thus facilitating its implant at the lesion site. These results highlight the biologic performance of biodegradable hyaluronic acid-based (HYAFF-11) scaffolds, which were shown to be suitable for deposition of the autologous extracellular matrix critical for ADSCs differentiation.