Synthesis and characterization of collagen type I-modified poly(DL-lactic acid) biomimetic material

Ethylenediamine-grafted poly(DL-lactic acid) (EMPLA) is a well-established biomaterial in our lab, which has pendent carboxyl groups and amino groups in its side chains, gives no acidic degrading products and possesses good hydrophilicity. In this study, a collagen type I-based poly(DL-lactic acid) biomimetic biomaterial (CPLA) was synthesized by introducing collagen type I into EMPLA with dicyclohexylcarbodiimide (DCC) as a dehydrating agent. A solution reaction method for CPLA synthesis was established. Fluorescein isothiocyanate (FITC) was employed to label the obtained CPLA polymer. The results indicate that collagen type I has been covalently incorporated into EMPLA by means of the said solution reaction method and that the collagen content in CPLA increases with increasing ethylenediamine graft ratios (EDA%) in EMPLA.