Biomimetic Mineralization of Hydroxyapatite Mediated by Poly(L-glutamic acid) Hydrogels in Simulated Body Fluid

Bioactive poly(L-glutamic acid)(PLGA) hydrogels were prepared by using adipic acid dihydrazide (ADH) as a crosslinking agent. The formation and growth of hydroxyapatite(HA) in the simulated body fluid (SBF) of different concentrations were characterized by various techniques. PLGA is a kind of anionic poly(amino acid) with abundant carboxylic groups, which favors the enrichment of calcium ions and formation of HA. The growth of HA with soaking time was detected at the surface and interior of the PLGA hydrogels. The mechanical properties of the PLGA hydrogels before and after mineralization were studied in dynamic rheology experiments. Being cytocompatible, the mineralized PLGA hydrogels were successfully applied for cultivation of adipose-derived stem cells(ASCs). These results presented a method of preparing HA/PLGA composite hydrogels, which might be used as a promising biomaterial for bone tissue engineering.