Js Li

Fabrication of poly(L-latic acid) scaffolds with wool keratin for osteoblast cultivation

As a natural protein, wool keratin was used to improve the cell affinity of poly(L-lactic acid) (PLLA). Small keratin particles were prepared from keratin solution by the spray-drying process. Keratin particles were blended with PLLA/1,4 dioxane solution and paraffin micro-spheres which were used as progens. After the mixture was molded and dried, the paraffin micro-spheres were removed by cyclohexane. PLLA/keratin scaffolds with controlled pore size and well interconnectivity were fabricated. Keratin releasing rate was detected by Fourier transform infrared (FTIR) after the scaffold was immersed into PBS up to 4 weeks. The surface chemical structure was examined by X-ray photoelectron spectroscope (XPS). The results suggested that the keratin could be held into the scaffold which was expected to improve the interactions between osteoblasts and the polymeric scaffolds.

Hydroxyapatite Nano-Particles Coating on the Pore Surface Within Poly(DL-lactic-co-glycolic acid) Scaffold

This paper describes a novel method for coating hydroxyapatite (HA, Ca10(PO4)6(OH)2) nano-particles onto poly(DL-lactic-co-glycolic acid) (PLGA) scaffold. Paraffin micro-spheres were used as porogens to create porous scaffolds and as vehicles to transfer HA into PLGA scaffold. HA nano-particles / 50% ethanol suspension was mixed with paraffin micro-spheres. The paraffin micro-spheres / HA suspension were pressed together to form a paraffin scaffold. After it was dried, the HA was coated on the surface of the paraffin spheres. Then, PLGA solution was cast into the inter space among the paraffin micro-spheres and then the solvent was evaporated. Afterwards, the paraffin micro-spheres were dissolved and removed. PLGA scaffolds with controlled pore size, good interconnectivity and high porosity were obtained. The HA nano-particles were transferred from the paraffin surface to the surface of the pore wall throughout the PLGA scaffold.

Antibacterial and nontoxic nano silver PLLA composites for tissue engineering

Poly-L-Lactide (PLLA) composites were prepared with nano silver particles with the weight ratios of nano silver particles to PLLA (Ag/PLLA) at 0.5%, 2.5%, 5%, 7.5% and 10% (w/w). In vitro cytotoxicity tests were conducted firstly to evaluate the cytotoxicity of the composites. The results indicated that PLLA, 0.5%, 2.5% and 5% Ag/PLLA composites were nontoxic to cells, while 7.5% and 10% Ag/PLLA composites were significantly toxic to cells. Cell proliferation experiments and antibacterial tests were also performed. 5% Ag/PLLA was found the best for cell proliferation with obvious antibacterial property. Thus, Ag/PLLA can be used as nontoxic scaffolds for tissue engineering with antibacterial property.