Assessment of biodegradability of polymeric microspheresin vivo: Poly (DL-lactic acid), poly (L-lactic acid) and poly (DL-lactide-co-glycolide) microspheres

To confirm a new evaluation technique for biodegradability of biopolymer microspheres in vivo condition, magnetic microsphere system was adopted for tracing the microspheres injected and lodged in mice. Microspheres of poly(DL-lactic acid), poly(L-lactic acid) and poly (DL-lactide-coglycolide)(PLGA) were prepared by solvent-extraction method and their organ distribution and biodegradation in mice was examined. Magnetic microspheres lodged in mice organs were recollected from the homogenates of mice organs with a constant flow magnetic separation apparatus. Recollected microspheres were observed by scanning electron microscopy and also were assayed for their magnetite content by atomic absorption spectrophotometry to evaluate the biodegradability of polymeric microspheres. This method seems to be practical and simple to estimate the biodegradability of biopolymers over the conventional methods.