Tuning biological properties of poly (vinyl alcohol) with amino acids and studying its influence on osteoblastic cell adhesion.

A new class of bio composite materials for orthopedic applications were prepared by blending polyvinyl alcohol (PVA) with certain amino acids (AA) such as glycine, lysine and phenyl alanine followed by in-situ cross-linking with citric acid (CT). CT cross-linked PVA offers sufficient chemical, thermal, and morphological stability by establishing intermolecular interaction. These biocomposite films were characterized for mechanical and thermal behaviors as well as analyzed through SEM, TGA and AFM studies. Zwitterionic characteristics of AA create cell-adhesive hydrophilic domains that act as potential cell-adhesion sites and facilitate osteointegration. Biocompatibility studies proved that PVA-AA/CT is non-toxic and exhibits good anti-bacterial activity. In-vitro bioactivity test and cell adhesion results predict that presence of AA is advantageous to enhance apatite growth and promote cell-substrate binding through modulating cellular activity of PVA polymer. Hydrophilicity of AA zwitterions significantly facilitates cell-substrate binding and CA cross-linking helps osteoblastic integration of PVA-AA/CT bio composite films. The rational design of microstructure with zwitterionic-hydrophilic domains is a key to enhance cell-substrate interaction of PVA-AAs/CT bio composites.