Enhanced degradation of poly(L‐lactide) containing arginine,tryptophan and lysine

Addition of arginine, tryptophan and lysine to poly(L ‐lactide) (PLLA) has resulted in a new series of enhanced degradation biomaterials. Degradation was performed at 70°C and degradation behavior was studied using water uptake, mass loss, pH value change, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and tensile properties. The results indicated that PLLA containing amino acids degraded more quickly than pure PLLA. In PLLA containing arginine, lysine, or tryptophan, crystallinity of the latter decreased after 8 days degradation while crystallinities of the other two composites increased. Destroying crystallites assists with deeper degradation and in vivo assimilation. Initial tensile strengths of all undegraded bars were almost the same. Furthermore, pH value changes indicated that additive amino acids could neutralize acidic degradation products, which may be a solution to the bacteria‐free inflammation induced by the acidic products. The results indicate that the composite biomaterials may be useful for future clinical application. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers