Chondrogenesis of human bone marrow mesenchymal cells by transforming growth factors β1 through cell shape changes on controlled biomaterials.

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.

Response of human mesenchymal stem cells (hMSCs) to the topographic variation of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) films.

The influence of the topographic morphology of poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) films on human mesenchymal stem cells (hMSCs) was investigated in this study. PHBHHx films with various surface characteristics were prepared by compression-molding, solvent-casting and electrospinning. The adhesion, proliferation and differentiation behaviors of hMSCs were significantly modulated by the surface characteristics of these films.

Modulation of gene expression and collagen production of anterior cruciate ligament cells through cell shape changes on polycaprolactone/chitosan blends.

Our previous study has illustrated that chitosan could enhance human anterior cruciate ligament (ACL) cells to exhibit a dramatic effect on increasing the gene expression of transforming growth factor beta1 (TGF-beta1), which is a specific gene for wound healing and collagen synthesis. However, human ACL cells could not adhere and proliferate well on chitosan. In order to overcome this drawback, we introduced polycaprolactone (PCL) into chitosan by the method of blending in this study.

Effects of the surface characteristics of polyhydroxyalkanoates on the metabolic activities and morphology of human mesenchymal stem cells.

Polyhydroxyalkanoates (PHAs) are a newer family of biomaterials for tissue-engineering applications. The objective of this study is to investigate the behavior of human mesenchymal stem cells (hMSCs) grown on various PHA films. The surface characteristics of PHA co-polymer films were varied by the content of 3-hydroxyvalerate (HV) or 3-hydroxyhexanoate (HHx) and by the film preparation methods such as compression-molding and solvent-casting.

Hyaluronic acid modulates gene expression of connective tissue growth factor (CTGF), transforming growth factor-beta1 (TGF-beta1), and vascular endothelial growth factor (VEGF) in human fibroblast-like synovial cells from advanced-stage osteoarthritis in vitro.

Intraarticular injection of hyaluronan (hyaluronic acid; HA) is the common way to treat osteoarthritis (OA) of knees. This treatment cannot only maintain the viscoelastic properties of knee but also release the OA pain. However, the exact molecular mechanism is unknown.

The phenotypic responses of human anterior cruciate ligament cells cultured on poly(epsilon-caprolactone) and chitosan.

The purpose of this study is to evaluate the phenotypic responses of human anterior cruciate ligament (ACL) cells on two biodegradable materials: poly(epsilon-caprolactone) (PCL) and chitosan. ACL cells cultured on PCL displayed phenotypes that were well spread with a developed cytoskeleton. In comparison, chitosan was not an appropriate substrate to support the attachment and spreading of ACL cells, which was attributed to the low fibronectin (FN) adsorption of chitosan.

Modulating the activities of human mesenchymal stem cells (hMSCs) and C3A/HepG2 hepatoma cells by modifying the surface characteristics of poly(3-hydroxybutyrate-co-3-hydroxyhexnoate) (PHBHHx).

The new biodegradable polyester poly(3-hydroxybutyrate-co-3-hydroxyhexnoate) (PHBHHx) has a potential application in tissue engineering. The aim of this study was to present a deeper picture of the relationship between the cellular behavior and the surface characteristics of PHBHHx films. The pristine PHBHHx film was prepared by adopting the compression-molding method, and then the acrylic acid molecules were grafted on PHBHHx membrane surface by UV irradiation.

The behavior of mesenchymal stem cells on micropatterned PLLA membranes.

The aim of this study was to evaluate the behaviors of mesenchymal stem cells (MSCs) on Poly(L-Lactic acid) (PLLA) membranes with different surface topographies. The double-sided micropatterns, island-patterned, and sunken-patterned PLLA membranes with diameters of 60 and 100 microm, were fabricated by the soft lithography method. The cell viability of MSCs on the island- and sunken-patterned PLLA membranes were characterized by scanning electron microscopy (SEM), MTT assay, and flow cytometric analysis.

Effects of cyclic mechanical stretching on the mRNA expression of tendon/ligament-related and osteoblast-specific genes in human mesenchymal stem cells.

The purpose of this study was to explore the influences of cyclic mechanical stretching on the mRNA expressions of tendon/ligament-related and osteoblast-specific marker genes in human MSCs seeded onto a collagen type I-coated surface. The stretch-induced mRNA expressions of mesenchymal stem cell protein (MSCP), matrix metalloproteinase-3 (MMP-3), and marker genes related to tendon/ligament cells (type I collagen, type III collagen, and tenascin-C) and those typical of osteoblasts (core binding factor alpha 1 (Cbfa1), alkaline phosphatase (ALP), and osteocalcin (OCN)) were analyzed by quantitative real-time PCR. The results revealed significant downregulation of MSCP and upregulation of MMP-3 genes in MSCs subjected to mechanical loading, regardless of the magnitude of the stretching (high or low).

Development of a useful technique to discriminate anterior cruciate ligament cells and mesenchymal stem cells--the application of cell electrophoresis.

Mesenchymal stem cells (MSCs) can differentiate into multiple nonhematopoietic cell lineages, including osteoblasts, chondrocytes, and ligament cells. The purpose of this study is to identify the difference between MSCs and anterior cruciate ligament (ACL) cells for the application of distinguishing these two cells during the process of MSCs differentiating into ACL cells. Although culture of MSCs and ACL cells have been studied extensively, it was found that these two cells could not be distinguished from their appearance, expression of surface antigens (including CD105, CD34, CD45, CD29, CD44, and CD71), alpha-smooth muscle actin, and mRNAs for type I collagen, type III collagen, and tenascin-C, based on a series of traditional methods for cell identification.

The differentiation of mesenchymal stem cells by mechanical stress or/and co-culture system.

Differentiation of mesenchymal stem cells (MSCs) into anterior cruciate ligament (ACL) cells is regulated by many factors. Mechanical stress affects the healing and remodeling process of ACL after surgery in important ways. Besides, co-culture system had also showed the promise to induce MSCs toward different kinds of cells on current research.

Recurrent infections caused by cefotaxime- and ciprofloxacin-resistant Salmonella enterica serotype choleraesuis treated successfully with imipenem.

We present a case of recurrent infection (infective spondilitis, psoas abscess, and bacteraemia) caused by a single strain of cefotaxime- and ciprofloxacin-resistant and bla(CMY-2)-containing Salmonella enterica serotype choleraesuis during a 4-month period in a patient with uremia. The patient was successfully treated with imipenem for 7 weeks. Our observation indicates that a carbapenem might be considered as a drug of choice for the treatment of infections caused by this emerging multi-resistant pathogen.