Hydrolytic degradation and in vivo resorption of poly-l-lactic acid-chitosan biomedical devices in the parietal bones of Wistar rats

OBJECTIVES: This study sought to describe events related to the degradation/resorption of a device composed of polylactic acid (PLA) after implantation into Wistar rats. METHODS: Five-millimeter-diameter PLA rigid scaffolds and flexible analogs were elaborated, bioactivated through culture with osteoblasts, and implanted into the parietal bones of adult Wistar rats after 15 days. After 3 months, the samples were recovered and analyzed via optical microscopy (histochemical techniques) and scanning electron microscopy. This research was approved by the animal ethics review committee of Universidad of Valle in Cali, Colombia, according to the endorsement of the ethics committee CEAS 001-016. RESULTS: Initially, there was surface erosion and fragmentation of the device, inducing an inflammatory response compatible with the foreign body reaction, in addition to the presence of a pseudocapsule and a mixed inflammatory infiltrate that was responsible for phagocytosis of the material. Regeneration of the defect via the apposition of new bone occurred simultaneously with resorption of the material. CONCLUSIONS: The results illustrated that the degradation/resorption of PLA occurs in a centripetal pattern.