Histological and biomechanical properties of regenerated articular cartilage using chondrogenic bone marrow stromal cells with a PLGA scaffold in vivo.

The properties of regenerated cartilage using bone marrow-derived mesenchymal stem cells (MSCs) and poly lactic-co-glycolic acid (PLGA) scaffold composites pretreated with TGF-beta3 were investigated and compared to the non-TGF-beta3 treated MSCs/PLGA composites in a rabbit model. We prepared MSCs/PLGA scaffold composites and pretreated it with TGF-beta3 for 3 weeks prior to transplantation. Then, composites were transplanted to the osteochondral defect in the rabbit knee.

Heparin conjugated polylactide as a blood compatible material.

A heparin-conjugated biodegradable polymer (PLA-heparin) by the direct coupling of heparin to polylactide (PLA) was synthesized and characterized. The surface exposed heparin content associated PLA-heparin was measured to be 0.067 microg/cm2.

A study of compatibility between cells and biopolymeric surfaces through quantitative measurements of adhesive forces.

The mechanism of cell adhesion to biomaterials or components of the extracellular matrix is an important topic in the field of tissue engineering and related biotechnological processes. Many factors affect cell adhesion, and many biochemical and biological studies have attempted to identify their roles in the adhesion mechanism. Systematic studies of this nature require quantification of the adhesive force of a cell to identify the effect of a specific factor.

Importance of integrin beta1-mediated cell adhesion on biodegradable polymers under serum depletion in mesenchymal stem cells and chondrocytes.

To evaluate the predominant mechanism of chondrogenic cell [mesenchymal stem cells (MSCs) and chondrocytes] adhesion under serum free conditions, we measured the surface roughness and wettability of poly(lactic acid:polyglycolic acid=75:25) (PLGA), poly(lactic acid) (PLA), and poly(-epsilon-caprolactone) (PCL)-coated glass plates. Also to evaluate the biological reactions involved in cell-polymer interactions, integrin beta1, one of the cell adhesion molecules, was blocked with monoclonal antibody. In cell attachment test, MSCs and chondrocytes adhesion to synthetic polymers in 1h were very low and ranged from 2.

A novel chemical modification of bioprosthetic tissues using L-arginine.

A novel chemical modification of biological tissues was developed by the direct coupling of bioactive molecule, L-arginine to bovine pericardium (BP). The modification involves pretreatment of BP using GA and followed by grafting arginine to BP by the reaction of residual aldehyde and amine group of L-arginine. BP was modified by direct coupling of bioactive molecules and the effect of L-arginine coupling on calcification and biocompatibility was evaluated in vitro and in vivo.