Effects of a Chitosan Scaffold Containing TGF‐β1 Encapsulated Chitosan Microspheres on In Vitro Chondrocyte Culture

Abstract

The objectives of this study were (1) to develop a three-dimensional chitosan scaffold in combination with transforming growth factor-beta1 (TGF-beta1)-loaded chitosan microspheres and (2) to evaluate the effect of the TGF-beta1 release on the chondrogenic potential of rabbit chondrocytes in the scaffolds. TGF-beta1 was loaded into chitosan microspheres using an emulsion-crosslinking method, resulting in spherical shapes with a size ranging from 0.3 to 1.5 microm. Controlled release of TGF-beta1, as measured by enzyme-linked immunosorbent assay (ELISA), was observed with chitosan microspheres over 7 days. Chitosan solutions (2% and 3%) were fabricated into two types of scaffolds with different pore morphologies and mechanical properties using a freeze-drying technique, with the result that scaffold with higher concentrations showed smaller pores and lower porosity, leading to a much stronger scaffold. The TGF-beta1 microspheres were incorporated into the scaffolds at a concentration of 10 ng TGF-beta1/scaffold and then chondrocytes seeded into each scaffold and incubated in vitro for 2 weeks. The 2% chitosan scaffolds showed higher cell attachment levels than the 3% chitosan scaffolds (P < 0.01), regardless of the TGF-beta1 microspheres. Both the proliferation rate and glycosaminoglycan (GAG) production were significantly higher for scaffolds incorporating TGF-beta1 microspheres than for the control scaffolds without microspheres 10 days after incubation. Extracellular matrix staining by Safranin O and immunohistochemistry for type II collagen both significantly increased in scaffolds containing TGF-beta1 microspheres. These results suggest that the TGF-beta1 microsphere incorporated in scaffolds have the potential to enhance cartilage formation.

Proliferation of chondrocytes on porous poly(dl-lactide)/chitosan scaffolds

“…The type II collagen was assessed according an immunohistochemical method described elsewhere [41]. The scaffolds were first fixed with 4% formaldehyde-buffered saline (pH 7.4), washed in 70% ethanol, dehydrated in ethanol at sequential concentrations, and then embedded in paraffin.…”

Adult Mesenchymal Stem Cells in Dental Research: A New Approach for Tissue Engineering

“…However, it remains to be determined to what extent the cells contributed to the clinical improvement, and current challenges point to the control of the differentiation and proliferation processes of stem cells once they have been implanted into patients t59). polymeric scaffolds and cultured in a medium enriched with Transforming Growth Factor-~(TGF-) and ascorbic acid (56). In the dental field, a study by Yamada et al investigated the possibility of a rapid and more effective bone regeneration around dental implants using an injectable tissue-engineered bone with MSCs and platelet-rich plasma (57).…”

Hydrocolloids and Medicinal Chemistry Applications

“…Polysaccharide microspheres have been explored for the controlled release of growth factors within three-dimensional tissue engineering scaffolds, to augment cellular proliferation and extracellular matrix formation. Lee et al (2004a) presented results suggesting that transforming growth factor (TGF-b1) which controls cell proliferation, and differentiation loaded into chitosan microspheres then incorporated into cell scaffolds seeded with chondrocytes, have the potential to enhance cartilage formation. In another study vascular endothelial growth factor (VEGF), essential for angiogenesis, has shown high encapsulation efficiency in alginate microspheres followed by sustained zero-order release by diffusion over 3 weeks (Elcin et al, 2001).…”