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ABSTRACT: Microporous poly(vinylidene fluoride) (PVDF) membranes with either dense or porous surface were prepared by isothermal immersion-precipitation of a casting solution in coagulation baths of different strengths. Onto the membrane surface, an amino acid (l-lysine) was immobilized by a dual-step chemical process. First, the membrane was grafted with poly(acrylic acid) (PAA) by means of plasma-induced free radical polymerization. Then, l-lysine was covalently bonded to the as-grafted PAA chains with the aid of a water-soluble carbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC). The highest attainable graft yield of PAA on PVDF membrane reached up to 0.64 mg/cm 2 . For immobilization of l-lysine on the membrane, the yields were found to depend on factors, such as concentration of EDC, activation time, and pH value. The maximal attainable immobilization yield was 0.65 mg/cm 2 . Furthermore, pheochromocytoma (PC12) cells were cultured on l-lysine/PAA/PVDF membranes. It was found that both the amount of l-lysine on the membrane and the surface structure had a marked influence on the cell activity. Thus, the present results could be useful for the development of strategies to promote the re-growth and regeneration of tissue in the nervous system.
Desalination. 09/2725; 234:16-18.
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ABSTRACT: PURPOSE: To evaluate the efficacy of using forward second harmonic generation (SHG) and 2-dimensional fast Fourier-transform (2D-FFT) analysis for the label-free characterization and quantification of morphologic changes in the corneal stroma after collagen crosslinking (CXL). SETTING: Department of Physics, National Taiwan University, Taipei, Taiwan. DESIGN: Experimental study. METHODS: En face forward SHG imaging and 2D-FFT analysis were performed on ex vivo porcine corneas at the depths of 100, 200, 400, and 800 μm. Morphologic changes in stromal collagen fiber in control, ultraviolet-A (UVA), riboflavin, and riboflavin-UVA treated porcine corneas were assessed. Hematoxylin-eosin staining and Sirius red staining were performed for comparison. RESULTS: Corneas after CXL treatment tended to have collagen fibers that were wavy compared with the linear pattern in normal corneas. Quantitative 2D-FFT analysis of forward SHG images also showed an increase in the standard deviations of the distribution of stromal collagen fiber orientations, which is indicative of the changed pattern of crosslinked stromal collagen fibers. CONCLUSIONS: Second harmonic generation imaging showed the morphologic changes in stromal collagen after CXL treatment. The linear collagen fibers in normal corneal stroma became wavy after treatment. With the introduction of 2D-FFT analysis, the morphologic changes can be quantified. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.
Journal of cataract and refractive surgery 05/2013; 39(5):779-788. · 2.75 Impact Factor
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ABSTRACT: Interactions between blood vessels and osteoblasts-bone-forming cells-are critical for successful bone development. We therefore investigated the endothelial differentiation capacity of mesenchymal stem cells (MSCs) derived from bone tissue. We found that fetal pre-osteoblast and adult trabecular bone-derived (TB) MSCs express similar surface markers as bone marrow (BM) MSCs and can differentiate into adipocytes, osteoblasts, and chondrocytes. However, when cultured in extracellular matrix (ECM) and endothelial differentiation conditions, bone-derived MSCs (B-MSCs) more readily form tubular structures and uptake acetylated low-density lipoproteins, fulfilling the functional criteria for endothelial cells (ECs). Moreover, addition of B-MSCs but not other cells significantly enhanced vessel formation in the in vivo chick chorioallantoic membrane assay. Mechanistically, this appears to be due to the upregulation of the endothelial transcription factor forkhead box protein C2 (FOXC2) and its downstream gene αvβ3 integrin/CD61in B-MSCs but not BMMSCs by laminin, a component protein of the ECM. Our findings not only reveal discrepant differentiation capacity for various tissue-specific MSCs, but also highlight the critical role of the niche-in this case, the ECM and its component proteins-in determining lineage commitment of stem cells.
Biomaterials 03/2013; · 7.40 Impact Factor
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ABSTRACT: While playing a major role in maintaining the mucociliary phenotype of respiratory epithelial cells (RECs), retinoids are critical determinants of their normal function. However, despite being a powerful biological agent, retinoic acid (RA) is generally not used in regenerative medicine due to its scarce bioavailability via conventional administration. Therefore, the ability to incorporate RA into biomaterials allows for a combination of the biological effects of RA and biomaterials in influencing cellular behavior. This study attempts to develop RA-loaded hyaluronan-derivative membrane (RA-HAm) and investigates how this membrane affects the mucociliary differentiation and aquaporins (AQP) formation of RECs. In a simulated in vitro culture condition, the RA release from membranes is maintained for 7days. On the 7th day, the cumulative release rate of RA from supportive biomaterials is around 87% under detect limitation. RECs cultured on RA-HAm reveal numerous mature ciliated cells and microvilli compared to aggregated cilia-like structures on hyaluronan-derivative membrane (HAm). Moreover, the expression levels of MUC5AC and AQP on RA-HAm are higher than those on HAm. The proposed model elucidates the release of hydrophobic RA from hyaluronan-derivative biomaterials. We believe that RA-loaded hyaluronan biomaterials are highly promising biomaterials for use in sinonasal surgery and tissue engineering of the respiratory system.
Acta biomaterialia 03/2013; · 3.98 Impact Factor
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ABSTRACT: We have applied a fluorescent molecule 3,6-bis(1-methyl-4-vinylpyridinium) carbazole diiodide (BMVC) for tumor targeting and treatment. In this study, we investigated the photo-induced antitumor effect of BMVC. In vitro cell line studies showed that BMVC significantly killed TC-1 tumor cells at light dose greater than 40 J/cm(2). The fluorescence of BMVC in the tumor peaked at 3 hours and then gradually decreased to reach the control level after 24 hours. In vivo tumor treatment studies showed BMVC plus light irradiation (iPDT) significantly inhibited the tumor growth. At day 24 after tumor implantation, tumor volume was measured to be 225 ± 79 mm(3), 2542 ± 181 mm(3), 1533 ± 766 mm(3), and 1317 ± 108 mm(3) in the iPDT, control, light-only, and BMVC-only groups, respectively. Immunohistochemistry studies showed the microvascular density was significantly lower in the iPDT group. Taken together, our results demonstrated that BMVC may be a potent tumor-specific photosensitizer (PS) for PDT.
BioMed research international. 01/2013; 2013:930281.
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ABSTRACT: The purpose of this study is to demonstrate pH-responsive chitosan is able to be used for cell fractionation under precise adjustment of medium pH. Cells were first seeded to attach on chitosan surface at medium pH 7.20 for 24 h. After raising medium pH to 7.65 for 1 h, cells with elongated morphology possessed rapider detachment rate and cells with round shape detached at a lesser rate. Therefore, successful cell separation has been achieved by choosing appropriate cell combination with different detachment rates without additional antibody or enzyme treatment and extensive washing steps. Furthermore, the method also could be applied to specific manipulation of viable cell populations from tissue specimen. Most importantly and interestingly, the efficiency of cell fractionation of our system could be theoretically predicted according to the individual cell detachment rate on pH-responsive chitosan surface, without considering the presence of heterotypic cells.
Biomaterials 11/2012; · 7.40 Impact Factor
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ABSTRACT: Autologous cell-based tissue engineering using three-dimensional scaffolds holds much promise for the repair of cartilage defects. Previously, we reported on the development of a porous scaffold derived solely from native articular cartilage, which can induce human adipose-derived stem cells (ASCs) to differentiate into a chondrogenic phenotype without exogenous growth factors. However, this ASC-seeded cartilage-derived matrix (CDM) contracts over time in culture, which may limit certain clinical applications. The present study aimed to investigate the ability of chemical crosslinking using a natural biologic crosslinker, genipin, to prevent scaffold contraction while preserving the chondrogenic potential of CDM. CDM scaffolds were crosslinked in various genipin concentrations, seeded with ASCs, and then cultured for 4 weeks to evaluate the influence of chemical crosslinking on scaffold contraction and ASC chondrogenesis. At the highest crosslinking degree of 89%, most cells failed to attach to the scaffolds and resulted in poor formation of new extracellular matrix. Scaffolds with a low crosslinking density of 4% experienced cell-mediated contraction similar to our original report on non-crosslinked CDM. Using 0.05% genipin solution, a crosslinking degree of 50% was achieved, and the ASC-seeded constructs exhibited no significant contraction during the culture period. Moreover, expression of cartilage-specific genes, synthesis and accumulation of cartilage-related macromolecules, and the development of mechanical properties were comparable to the original CDM. These findings support the potential use of a moderately (i.e., approximately one-half of the available lysine or hydroxylysine residues being crosslinked) crosslinked CDM as a contraction-free biomaterial for cartilage tissue engineering.
Tissue Engineering Part A 10/2012; · 4.64 Impact Factor
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ABSTRACT: Context: For 2000 years, traditional Chinese medicine has been used as a remedy for general health improvement, including the fight against aging. Pearl powder has recently been used as a health food that has antioxidant, antiaging, antiradioactive, and tonic activities for cells; it is also applied to cure aphthous ulcer, gastric ulcer, and duodenal ulcer on clinical therapy. In addition, the mother of pearl, nacre, could enhance the cell adhesion and tissue regeneration of skin fibroblasts. Objective: Fibroblast is regarded as indispensable in the processes of wound healing. Therefore, the effect of pearl extract (PL) on fibroblasts is investigated in this study. Materials and methods: PL is produced by a room temperature super extraction system (Taiwan patent no. I271 220). DMEM medium containing PL (300 μg/mL) was used to examine the effect of migration-promoting potential on human fibroblast cell line or human primary fibroblast cells in a wound healing model in vitro. Results: Medium containing PL (300 μg/mL) demonstrated that the migratory cell numbers of fibroblasts were three times more than that without PL, and mRNA expression of collagen type III was higher than in collagen type I in fibroblasts. It revealed a migration-promoting potential of human fibroblasts in a wound healing model in vitro. Discussion and conclusion: The present study found that the migration-promoting effect in PL, which could be a supplement in cell culture. These data suggest PL could be useful for enhancing the wound healing of fibroblasts.
Pharmaceutical Biology 10/2012; · 0.88 Impact Factor
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ABSTRACT: Glandular organs feature ramified structures that are important for regulating physiological transport. The aim of this study was to develop a biomaterial-assisted, serum-free culture system to generate branching structures in explants of glandular organs. The fetal mammary gland (MG) was selected as the model organ to study the formation of glandular structure. Among the many biomaterials tested, chitosan demonstrated a superior effect in promoting branch formation in MGs. The morphogenetic effect toward MG branching was chitosan specific and not observed with other analogs with similar chemical compositions or structures. The molecular weight and specific linkages in the chitosan polymer were important parameters in mediating the morphogenetic effect. MG explants from different anatomical locations effectively promoted structure formation. Blocking endogenous fibroblast growth factor 10 (FGF10) inhibited the morphogenetic effect of chitosan, indicating that the chitosan effect was FGF10 dependent. This work demonstrates the feasibility of creating a serum-free system that is competent in facilitating tissue morphogenesis in MG. MG tissue structure can be efficiently generated in a biocompatible system, which was assisted by biomaterials.
Tissue Engineering Part A 08/2012; · 4.64 Impact Factor
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ABSTRACT: The phenotypic responses of human bone marrow mesenchymal cells (hBMSCs) on different ratio of chitosan/polycaprolactone (PCL) blends were investigated in this study. The results showed that hBMSCs existed different morphology on chitosan/PCL blends due to the different adhesion characteristic of cell on neat PCL and neat chitosan. Interestingly, comparing to hBMSCs on neat PCL, hBMSCs aggregated to form spheroid and to express ascendant trend of transforming growth factor β1, collagen type II, collagen type X, and Sox9 mRNA on the chitosan/PCL blended substrates with the decrease of PCL content. To confirm chondrogenesis of hBMSCs with spheroid on test substrates, Alcian Blue and Safranin O staining were used to detect the cartilaginous extracellular matrix (ECM). It revealed hBMSCs with spheroid on neat chitosan and 10 wt % PCL did turn to chondrogenic differentiation and synthesize cartilaginous ECM. Therefore, these findings provided new insights into the role of chitosan/PCL blended material could mediate the endogenous gene expression of hBMSCs to alter the phenotypic behavior through mediating the cell shape. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 100A:3344-3352, 2012.
Journal of Biomedical Materials Research Part A 06/2012; 100(12):3344-52. · 2.63 Impact Factor
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ABSTRACT: Adipose-derived stem cells (ASCs) are a potential source of abundant mesenchymal stem cells and represent a promising cell-based therapy for tissue damage or degeneration conditions. Previous investigations have demonstrated enhanced therapeutic effects of ASCs in a three-dimensional spheroid culture formulation. In this study, we hypothesize that a composite membrane made of chitosan/gelatin (C/G) is beneficial to facilitate transfer of human ASCs in spheroids. Increasing chitosan content within the blends enhanced the mechanical properties of the sample, including tensile strength and elongation-at-break ratio. Although ASC spheroids developed shortly after seeding on pure chitosan films, increasing gelatin proportion in the C/G blends promoted cell adhesion onto the membranes. We also found that ASCs did not proliferate on chitosan films, but C/G blends of different ratios supported ASC proliferation in the first 4 days of culture. However, ASCs on all C/G blends started to detach from the films to form spheroids after day 4, while ASCs on pure gelatin films remained attached and continued to grow. Gradual gelatin release from the C/G blend films, leading to enriched chitosan content in the blends, probably encouraged ASC detachment and spheroid formation. We placed porous collagen matrix on ASC-seeded C/G blends to simulate the application of ASC-seeded C/G films onto injured tissue and found that a C/G film composed of 75% chitosan could facilitate significantly more cell transfer into the overlying collagen sponge. Therefore, a blend film containing 75% chitosan and 25% gelatin showed promising results to serve as a biomaterial for human ASC-based cell therapy.
Journal of Biomedical Materials Research Part B Applied Biomaterials 05/2012; 100(5):1369-77. · 2.15 Impact Factor
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ABSTRACT: The purpose of this study was to induce the differentiation of neural stem/precursor cells (NSPC) more towards neurons than glial cells by the combination of media, biomaterials and extracellular matrix (ECM) proteins. Considering the role of serum, 10% fetal bovine serum or its fractions were added to DMEM/F12 medium to examine the effect of the differentiation-promoting potential on cultured NSPC isolated from embryonic rat cerebral cortex. The NSPC were cultured for 7 days, after which differentiation was assayed using immunocytochemistry for lineage specific markers. It was demonstrated that molecules promoting neuron differentiation were present in serum with molecular weight <100 kDa, which could dominate the differentiation of NSPC principally into neurons in the presence of basic fibroblast growth factor. In contrast, NSPC were induced to differentiate predominantly into glial cell phenotypes in the presence of whole serum components. Based on medium containing serum fraction, semi-quantification showed that the MAP2-positive percentage of the immunoreactive ratio within migrated cells could be promoted over 85% by combining poly(ethylene-co-vinyl alcohol) biomaterial and fibronectin matrix protein. These results are very encouraging, since an environment favorable for neuronal differentiation should be useful in the development of strategies for controlling the behavior of NSPC in neuroscience research.
Acta biomaterialia 04/2012; 8(8):3035-48. · 3.98 Impact Factor
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ABSTRACT: The aim of this prospective study was to evaluate whether blending two kinds of biomaterials, chitosan and polycaprolactone (PCL), can be used as scaffold and carrier for growth and differentiation of corneal endothelial cells (CECs).
A transparent, biocompatible carrier with cultured CECs on scaffold would be a perfect replacement graft. In the initial part of experiment, for essential and biocompatible test, chitosan and PCL were evaluated respectively and blended in various proportions by coating. In the later part of this study, for evaluation of potential application, homogenous solutions of 25%, 50%, and 75% PCL compositions were attempted to structure blend membranes.
Chitosan, PCL 25, PCL 50, and PCL 75 blends could maintain transparency of culturing substrata. BCECs were found to be reached confluence successfully after 7 days on PCL 25, PCL 50, and PCL 75. The expression of tight junction and extracellular matrix protein were observed as well. Alternatively, only PCL 25 could make blend membrane with enough strength during preparation for carrier in culture. On this blend membrane, the growth pattern and phenotype of BCECs could be observed well.
A ratio of 75:25 (chitosan:PCL) blends showed enough mechanical properties as well as suitable support for cellular activity in cultivating BCECs. Thus, a novel methodology of biodegradable carrier from chitosan and PCL has potential to be a good replacement scaffold for raising CECs for clinical transplantation.
Molecular vision 01/2012; 18:255-64. · 2.20 Impact Factor
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ABSTRACT: The amniotic membrane (AM) has been widely used in the field of tissue engineering because of the favorable biological properties for scaffolding material. However, little is known about the effects of an acellular AM matrix on the osteogenic differentiation of mesenchymal stem cells. In this study, it was found that both basement membrane side and collagenous stroma side of the acellular AM matrix were capable of providing a preferential environment for driving the osteogenic differentiation of human dental apical papilla cells (APCs) with proven stem cell characteristics. Acellular AM matrix potentiated the induction effect of osteogenic supplements (OS) such as ascorbic acid, β-glycerophosphate, and dexamethasone and enhanced the osteogenic differentiation of APCs, as seen by increased core-binding factor alpha 1 (Cbfa-1) phosphorylation, alkaline phosphatase activity, mRNA expression of osteogenic marker genes, and mineralized matrix deposition. Even in the absence of soluble OS, acellular AM matrix also could exert the substrate-induced effect on initiating APCs' differentiation. Especially, the collagenous stroma side was more effective than the basement membrane side. Moreover, the AM-induced effect was significantly inhibited by U0126, an inhibitor of extracellular signaling-regulated kinase 1/2 (ERK1/2) signaling. Taken together, the osteogenic differentiation promoting effect on APCs is AM-specific, which provides potential applications of acellular AM matrix in bone/tooth tissue engineering.
Biomaterials 01/2012; 33(2):455-63. · 7.40 Impact Factor
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ABSTRACT: As a potential solution for patients to retrieve their lost salivary gland functions, tissue engineering of an auto-secretory device is profoundly needed. Under serum-free environment, primary human parotid gland acinar (PGAC) cells can be obtained. After reaching confluence, PGAC cells spontaneously form three-dimension (3D) cell aggregations, termed post-confluence structure (PCS), and change their behaviors. Poly (lactic-co-glycolic acid) (PLGA) has been widely used in the field of biomedical applications because of its biodegradable properties for desired functions. Nonetheless, the role of PLGA in facilitating PGAC cells to form PCS has seldom been explored to recover epithelial characteristics. In this study, PGAC cells were found to have a greater tendency to form PCS on PLGA than on tissue culture polystyrene (TCPS). By tracing cell migration paths and modulating E-cadherin activity with specific inhibitor or antibody, we demonstrated that the static force of homophilic interaction on surfaces of individual cells, but not the dynamics of cell migration, played a more important role in PCS formation. Thus, PLGA was successfully confirmed to support PGAC cells to form more PCS through the effects on enhancing E-cadherin expression, which is associated with FAK/ILK/Snail expression in PGAC cells. This result indicates that selective appropriate biomaterials may be potentially useful in generating 3D PCS on two-dimension (2D) substrate without fabricating a complex 3D scaffold.
Biomaterials 01/2012; 33(2):464-72. · 7.40 Impact Factor
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ABSTRACT: 3-dimensional microcarrier (3D-MC) cell culture systems are often used for expansion of stem cells including mesenchymal stem cells (MSCs) for high cell volumes required in clinical applications. However, compared to 2-dimensional (2D) cell culture, effects of 3D-MC systems on MSC differentiation have not been well studied. In this study, the behavior of various sources of MSCs from two species was observed and compared on 3D collagen I-coated-MCs (COL-MC) versus 2D culture. Proliferation of all MSCs cultured on 3D COL-MC was much decreased compared to 2D culture. Unexpectedly, COL-MC-cultured MSCs underwent spontaneous osteogenesis without exogenous addition of biochemical factors, as evidenced by increased osteogenic genes expression, ALP activity, calcium deposition, and collagen I secretion. Furthermore, MSCs cultured on 3D-MC alone without collagen I coating is sufficient to induce osteogenesis. The spontaneous lineage commitment induced by 3D-MC culture was mediated by increased cytoskeletal tension and actomyosin contraction of MSCs, which could be prevented by latrunculin B and blebbistatin, inhibitors of cytoskeletal tension and actomyosin contraction respectively. Our findings show that the combination of bioengineered MC and MSCs alone can induce specific lineage commitment very efficiently. These data have strong implications in simplifying tissue engineering strategies for therapeutic applications.
Biomaterials 01/2012; 33(2):556-64. · 7.40 Impact Factor
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ABSTRACT: In this study, biomaterials with different hydrophobic properties including polyvinyl alcohol (PVA), poly(ethylene-co-vinyl alcohol) (EVAL), tissue culture polystyrene (TCPS), and polyvinylidene fluoride (PVDF) were examined in the bovine corneal endothelial cells (BCECs) culture system to elucidate their possible impact on clinical demand and scientific interest. It was found that BCECs were inhibited to attach onto the PVA surface. Conversely, relatively more hydrophobic biomaterials EVAL, TCPS, and PVDF successfully initiate BCEC adhesion. Compared to EVAL, cultured BCECs on TCPS and PVDF exhibited higher viability. Furthermore, fibroblastic transformation on EVAL and TCPS was observed at day 17, but BCECs maintained typical hexagonal shape on the PVDF surface at day 21. This phenomenon can be rescued by previously coating type IV collagen on TCPS but not on EVAL. In addition, when BCECs were cultured on PVDF, the expressions of gap junction connexin-43, differentiation marker N-cadherin, and tight junction ZO-1 were well-developed, resembling the physiological phenotypes. After examining the type IV collagen expression by Western blot analysis and protein absorption test, a possible explanation for the better proliferation and preservation of BCECs on the PVDF substrate is that PVDF is a bioactive substratum which enables BCECs to synthesize and reserve more extracellular matrix type IV collagen, paving an important way to provide a more preferential environment for BCEC cultures. Accordingly, promoting CEC growth effects after cell-biomaterial association may be applied to the tissue engineering of corneal endothelium.
Journal of Biomedical Materials Research Part A 01/2012; 100(1):252-60. · 2.63 Impact Factor
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ABSTRACT: Adipose-derived stem cells (ASCs) have valuable applications in regenerative medicine, but maintaining the stemness of ASCs during in vitro culture is still a challenging issue. In this study, human ASCs spontaneously formed three-dimensional spheroids on chitosan films. Most ASCs within the spheroid were viable, and the cells produced more extracellular molecules, like laminin and fibronectin. Comparing to monolayer culture, ASC spheroids also exhibited enhanced cell survival in serum deprivation condition. Although cell proliferation was inhibited in spheroids, ASCs readily migrated out and proliferated upon transferring spheroids to another adherent growth surface. Moreover, spheroid-derived ASCs exhibited higher expansion efficiency and colony-forming activity. Importantly, we demonstrated that spheroid formation of human ASCs on chitosan films induced significant upregulation of pluripotency marker genes (Sox-2, Oct-4 and Nanog). By culturing the ASC spheroids in proper induction media, we found that ASC differentiation capabilities were significantly enhanced after spheroid formation, including increased transdifferentiation efficiency into neuron and hepatocyte-like cells. In a nude mice model, we further showed a significantly higher cellular retention ratio of ASC spheroids after intramuscular injection of spheroids and dissociated ASCs. These results suggested that ASCs cultured as spheroids on chitosan films can increase their therapeutic potentials.
Biomaterials 12/2011; 33(6):1748-58. · 7.40 Impact Factor
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ABSTRACT: The purpose of this study is to demonstrate pH-responsive chitosan is able to control cell behavior in response to small changes in environmental pH, which is at useful pH suitable for recovering cultured cells without additional enzymatic treatment and extensive washing steps. HeLa cells attached and spread well on chitosan at pH 6.99 and 7.20. When the pH was increased to 7.65, over 90% of cells would rapidly detached from chitosan surface within 1 h. Similarly, fibronectin adsorbed on chitosan at pH 7.20 also rapidly desorbed after increasing the medium pH. Most importantly and interestingly, medium pH adjustment could be facilitated by altering environment pCO(2). It was found over 80% of HeLa cells could be recovered from chitosan surface within 1 h and the viability of detached cells was more than 95% by transferring the culture plate from incubator to atmospheric condition. Additionally, chitosan substrate could effectively control attachment/detachment of various types of cells including cell lines HaCaT, H1299, NIH-3T3, and primary corneal fibroblasts, indicating the technology described here is easily reproducible and should be promising for controlling rapid fibronectin adsorption/desorption and cell attachment/detachment for tissue engineering applications.
Biomaterials 11/2011; 33(5):1336-42. · 7.40 Impact Factor
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ABSTRACT: Although various behaviors of corneal endothelial cells (CECs) have been investigated, the interaction of CECs with different biodegradable biomaterials has not been systematically well explored. Thus, two common biodegradable biomaterials with dissimilar characteristics, chitosan and polycaprolactone (PCL), were examined in bovine CEC (BCEC) culture systems to elucidate their possible impact on clinical demand and scientific interest. The interaction between cells and matrices was also surveyed. Pure PCL could not be used for observation because of its opacity. Nevertheless, BCECs did not adhere and proliferate well on chitosan. To overcome this drawback, we developed blends using various proportions of chitosan and PCL: PCL 25, PCL 50, and PCL 75. As the content of PCL increased in the blends, BCECs showed greater degrees of adhesion and proliferation. Furthermore, cells reached confluence and maintained their typical hexagonal shape at day 7 on blends PCL 50 and PCL 75. In addition, when BCECs were cultured on the blends, the expressions of the differentiation marker N-cadherin and tight junction marker ZO-1 were well developed, resembling the physiological phenotypes. A possible explanation for the increased proliferation and preservation of BCECs on the blends is that blending chitosan and PCL could create a bioactive substratum. This method could regulate gene expression to synthesize more extracellular matrix type IV collagen, paving an important way to provide a favorable environment for BCEC cultures. Accordingly, promoting CEC growth effects by blending may be applied to the tissue engineering of corneal endothelium.
Colloids and surfaces. B, Biointerfaces 10/2011; 90:236-43. · 2.60 Impact Factor
