In vivo degradation of porous poly(propylene fumarate)/poly(DL-lactic-co-glycolic acid) composite scaffolds

Abstract

This study investigated the in vivo degradation of poly(propylene fumarate) (PPF)/poly(DL-lactic-co-glycolic acid) (PLGA) composite scaffolds designed for controlled release of osteogenic factors. PPF/PLGA composites were implanted into 15.0mm segmental defects in the rabbit radius, harvested after 12 and 18 weeks, and analyzed using histological techniques to assess the extent of polymer degradation as well as the tissue response within the pores of the scaffolds. Polymer degradation was limited to micro-fragmentation of the scaffold at the ends and edges of the implant at both 12 and 18 weeks. The tissue within the pores of the scaffold consisted of fibrous tissue, blood vessels and some inflammatory cells. In areas where polymer breakdown was evident, an increased inflammatory response was observed. In contrast, areas of bone ingrowth into the polymer scaffold were characterized by minimal inflammatory response and polymer degradation. Our results show that minimal degradation of porous PPF occurs within 18 weeks of implantation in a rabbit model. Further, the in vivo degradation data of porous PPF/PLGA scaffolds are comparable with earlier obtained in vitro data.

A neuroinductive biomaterial based on dopamine

“…The ester bond in PCD rendered the polymer biodegradable, with a half-life in PBS solution (29,30) of Ϸ50 days at 37°C (Fig. 2).…”

Development and characterization of a rabbit alveolar bone nonhealing defect model

“…In addition to the defect size, the in vivo model selected should mimic the clinical situation as closely as possible 3,4 and provide a challenging environment that will allow the investigators to discriminate the healing potential of various biomaterials and tissue-engineering constructs. 5 Although both cranial cavitational defect [6][7][8][9] and long bone segmental defect [10][11][12] models are commonly performed in small rodents to test bone regeneration materials, they cannot address the unique masticatory stresses and cell populations seen in the wound healing environment of alveolar bone defects. 13,14 Previous studies have created 4-mm defects in the rat mandible, which fail to heal at 24 weeks.…”

The Implications of Polymer Selection in Regenerative Medicine: A Comparison of Amorphous and Semi‐Crystalline Polymer for Tissue Regeneration

“…[6][7][8] While some studies did observe an increased inflammatory response and osteoclastic activity, only the full impact of these events on tissue formation may be determined by monitoring complete scaffold degradation. Since bone resorption was observed adjacent to PLAGA absorbable screws at 4 months [9] and PLAGA constructs used in segmental bone defects are likely to contain a greater volume of polymer, long-term polymeric degradation studies are imperative.…”