Cellular interactions and degradation of aliphatic poly(ester amide)s derived from glycine and/or 4-amino butyric acid

A series of poly(ester amide)s derived from amino acid (glycine or 4-amino butyric acid), diol (1,6-hexanediol or 1,4-butanediol) and sebacoyl chloride were prepared by interfacial polymerization. FT-IR analysis indicated that for poly(ester amide)s derived from glycine, only amide–amide hydrogen bonds and hydrogen-bonded C=O ester groups were established, whereas the poly(ester amide)s derived from 4-amino butyric acid contained amide–amide hydrogen bonds and amide–ester hydrogen bonds, including NH groups and C=O ester groups in free state. The biodegradability was estimated by weight residue of poly(ester amide) films in pH 6 buffer solution with papain at 37°C. The poly(ester amide) films derived from glycine demonstrated significantly improved degradability compared to the poly(ester amide) films derived from 4-amino butyric acid. This difference of degradation rate could be explained by the bonding state in C=O ester groups. The cellular interaction of the poly(ester amide)s was studied by measuring the proliferation of human dermal fibroblasts on the polymer films. The cells proliferated significantly faster on poly(ester amide) films derived from 4-amino butyric acid than on poly(ester amide) films derived from glycine. These results suggest that the poly(ester amide) prepared in this study may serve as a potential cell-compatible biomedical material.