Shrinkage-free preparation of scaffold-free cartilage-like disk-shaped cell sheet using human bone marrow mesenchymal stem cells

Aiming for the clinical application of cartilage regeneration, a culture method for mesenchymal stem cells (MSCs) derived from human bone marrow to obtain scaffold-free cartilage-like disk-shaped sheet of uniform sizes without the shrinkage was investigated. A disk-shaped cell sheet having the same diameter as that of the membrane without the shrinkage was formed after the cultivation of MSCs (18.6 × 10(5)cells/well) for 3 weeks in a cell culture insert (CCI) containing a flat membrane whose porosity was 12%, while 6.2 and 31.0 × 10(5)MSCs/well, respectively, resulted in the shrinkage of the aggregate and the hole formation in the center part of the sheet. Cell aggregates shrunk also in a 96-well plate and CCIs having lower porosity. The disk-shaped cell sheet showed the comparable thickness (1.2mm) and sulfated glycosaminoglycan (sGAG) density to those of the pellet formed in a pellet culture. The gene expression levels of aggrecan and type II collagen in the disk-shaped cell sheet were not lower than those in the pellet. In conclusion, the usage of CCI having 12% porosity and 18.6 × 10(5)MSCs/well could avoid the shrinkage from the formation of the scaffold-free cartilage-like disk-shaped cell sheet.     

Effects of dissolved oxygen level on cell growth and total lipid accumulation in the cultivation of Rhodotorula glutinis

The total amount of lipids produced in Rhodotorula glutinis is a subject which has attracted increasing attention due to the potential biodiesel conversion from these microbial oils. The effects of the dissolved oxygen (DO) level in lipid accumulation were examined in this study. Variations of different medium volumes (30, 40 and 50ml) and shaking speed (60, 150 and 210rpm) in the flask trials were adopted to explore the DO effects on lipid production. All of the results revealed that a low DO could retard cell growth, while enhancing lipid accumulation. The 5l-fermentor results also confirm that a low DO (25 ± 10%) batch could have higher lipid content than that of high DO batch (60 ± 10%). Nevertheless, the DO level would not obviously affect the lipid composition profile. Oleic acid (C18:1) was the primary fatty acid in both batches. Due to the slow biomass growth rate resulting from the low DO, a two-stage DO controlled strategy (consisting of a high DO stage and following a low DO stage) was performed to improve the cell growth and lipid accumulation simultaneously. However, the strategy was not successful on the enhancement of total lipid production as compared to other batches. Conclusively, even a low DO could retard cell growth; the total production of lipids in the batch with low DO was higher that of the high DO batch due to the enhancement of lipid accumulation. Therefore, the batch operation of R. glutinis at the low DO was suggested for the purpose of lipid production.     

Predicting quality decay in continuously passaged mesenchymal stem cells by detecting morphological anomalies

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Glucose-stimulated insulin secretion of various mesenchymal stem cells after insulin-producing cell differentiation

Mesenchymal stem cells (MSCs) are capable of crossing germinative layer borders and are obtainable in high numbers via in vitro cultures. Therefore, many researchers have searched for diverse sources of MSCs. Recently the generation of glucose-responsive insulin-producing cells (IPCs) from MSCs has shown immense potential for the treatment of type 1 diabetes mellitus (T1DM) due to a lack of pancreas donors. In this study, we compared the growth potency of four kinds of MSCs derived from bone marrow, Wharton's jelly, adipose tissue, and the periosteum. In addition, in vitro differentiation of these MSCs into IPCs was also investigated. After 2weeks of IPCs differentiation, we compared the expression of the insulin gene and protein using RT-qPCR and immunofluorescence staining. Only IPCs derived from periosteum-derived progenitor cells (PDPCs) showed a response to glucose concentration. Glucose stimulated insulin secretion was conclusive evidence of the potential functionality of IPCs. Therefore, PDPCs are a promising alternative stem cell source for IPCs differentiation.     

Nanotechnology and Food: Brief Overview of the Current Scenario

The rapidly expanding sector of nanotechnologies has applications in every industrial sector. The production of food of animal origin recognizes several possibilities for technological development through the use of nanomaterials, at animal farming, food processing and product storage levels. Direct use of nanomaterials during these production stages, as well as the uptake from the environment, can lead to the presence of such materials in the final product. In this context analytical methods for the detection and characterization of nanomaterials in complex food matrices and toxicological data are strongly needed to assess the risk for consumers.     

Compare the effects of chondrogenesis by culture of human mesenchymal stem cells with various type of the chondroitin sulfate C

Chondroitin sulfate C (CSC) is a kind of glycosaminoglycans (GAGs) with molecular weights of 10,000 to 50,000 Da and a high charge density. GAGs are major components in extracellular matrix (ECM), which play important role in the regulation of cell proliferation, migration, and differentiation. In this study, we studied the effects of chondroitin sulfate C (CSC) on the differentiation of human mesenchymal stem cells (MSCs) toward the chondrocyte lineage. The MSCs were either cultured on type II collagen (COL II) scaffolds with high molecular weight CSC addition in the medium (free CSC) or with free oligosaccharide CSC. Special attention was given to the effects of MSCs cultured on CSC cross-linked type II scaffolds (cross-linked CSC). According to the analysis of histology stain, gene expression, and ECM secretion, our results showed that MSCs cultured with free CSC, free oligosaccharides CSC, and on the cross-linked CSC scaffolds all would be induced into chondrocytes. Moreover, free oligosaccharide CSC present in the microenvironment could significantly up-regulate MSC chondrogenesis gene expression and stimulate cartilage ECM accumulation more than free CSC with high molecular weight after 3-week induction. Importantly, cross-linked CSC had the most excellent effects on the MSC chondrogenesis. Thus, we believed that cross-linked CSC in the scaffold would play the similar roles with free oligosaccharide CSC in the medium. Cross-linked CSC would be a potential candidate for cartilage repair in the cell therapy and tissue engineering.     

Muscle stem cell isolation and in vitro culture for meat production: A methodological review

Cultured muscle tissue-based protein products, also known as cultured meat, are produced through in vitro myogenesis involving muscle stem cell culture and differentiation, and mature muscle cell processing for flavor and texture. This review focuses on the in vitro myogenesis for cultured meat production. The muscle stem cell–based in vitro muscle tissue production consists of a sequential process: (1) muscle sampling for stem cell collection, (2) muscle tissue dissociation and muscle stem cell isolation, (3) primary cell culture, (4) upscaled cell culture, (5) muscle differentiation and maturation, and (6) muscle tissue harvest. Although muscle stem cell research is a well-established field, the majority of these steps remain to be underoptimized to enable the in vitro creation of edible muscle-derived meat products. The profound understanding of the process would help not only cultured meat production but also business sectors that have been seeking new biomaterials for the food industry. In this review, we discuss comprehensively and in detail each step of cutting-edge methods for cultured meat production. This would be meaningful for both academia and industry to prepare for the new era of cellular agriculture.     

Hair biology: an update

In the past few years, the hair follicle has started revealing its beauty and mysteries. The existence of a growth and regeneration cycle, together with a unique tissue organization and complex regulatory network, make it a true paradigm of tissue homeostasis and dermal–epithelial crosstalk. In this brief review, I will describe some of the most recent results obtained in this very active research field of hair biology, underlining the diversity of the molecular signals that control hair growth and pigmentation.     

Myogenic induction of human mesenchymal stem cells by culture on dendrimer-immobilized surface with d-glucose display

Culture surfaces were designed by immobilizing dendrimer with d-glucose display, that is, 1st-generation (G1) and 3rd-generation (G3) dendrimer surfaces. In the cultures of human mesenchymal stem cells (hMSCs), the effect of the prepared culture surfaces was examined in terms of regulating cell morphology and differentiation. The time-lapse observation revealed that the cells on the G3 surface showed more dynamic behaviors of temporal stretching and contracting associated with stimulated migration, as compared with the cells on the G1 and plain surfaces. On the G3 surface, moreover, a frequency of round-shaped cells increased, and spreading of the cells was appreciably suppressed. From the cytoskeletal staining of F-actin, it was found that the immature stress fibers were of significance in the cells on the G3 surface. In addition, the cells on the G3 surface expressed RhoA inactivation and Rac1 activation during the culture, indicating that the G3 surface permits the regulation of RhoA and Rac1 expression associated with altering in cellular morphology and migratory behaviors. It was also found that desmin expression was, in particular, promoted on the G3 surface, thus supporting the consideration that a balance of Rho family GTPases activation induces myogenesis in hMSCs. The current results suggest that the dendrimer surface can be a potential tool for the guided differentiation of hMSCs directing to myocyte-like cells in the absence of an aqueous myogenesis-inducing factor.     

E-cadherin gene-engineered feeder systems for supporting undifferentiated growth of mouse embryonic stem cells

Conventionally, embryonic stem (ES) cells are cultured on a cell layer of mouse embryonic fibroblasts (MEFs) as feeder cells to support undifferentiated growth of ES cells. In this study, cell–cell interactions between mouse ES and feeder cells were artificially engineered via an epithelial cell adhesion molecule, E-cadherin, whose expression is considerable in ES cells. Mouse mesenchymal STO and NIH3T3 cells that were genetically engineered to express E-cadherin were used in ES cell cultures as feeder cells. ES cells cultured on the E-cadherin-expressing feeder cells maintained the expression of stem cell markers, alkaline phosphatase (AP), Oct3/4, Nanog and Sox2, and the efficiency of AP-positive colony formation was comparable to MEFs, and much better than parental STO and NIH3T3 cells. Furthermore, ES cells maintained on the E-cadherin-expressing feeder cells possessed the ability to differentiate into the three germ layers both in vitro and in vivo. The results indicated that E-cadherin expression in feeder cells could improve the performance of feeder cells, which may be further applicable to create new artificial feeder cell lines.