A Novel Scaffold Implant Comparison to Current Biomaterials

Abstract

Objective: 1) Develop a model to evaluate biocompatibility and integrationof novel porous bioscaffolds for maxillofacial and plastic reconstruction usingsphere-templated angiogenic regeneration (STAR) technology. 2) Demonstrate substrate-independence of STAR technology. 3) Perform a pilot study to compare a novel STAR implant withcurrently available synthetic and biologic soft tissue implants. Method: Five pigs underwent dorsal subcutaneous implantation of a polypropylene-based material coated with precision pore silicone granules (STAR scaffold), expanded polytetrafluoroethylene, human dermis, and porcine dermis. Sham dissection was also performed. Specimens were harvested 7, 21, 90, and 180 days after surgery and evaluated histologically for inflammation, neovascularization, and collagen deposition. Results: All materials and sham sites induced a mild to moderate inflammatory response that decreased over time, except for human dermis, which elicited persistent marked inflammation. Overall, expanded polytetrafluoroethylene elicited the most favorable foreign body reaction and demonstrated minimal chronic inflammation. The STAR scaffold demonstrated the greatest number of foreign body giant cells adjacent to the silicone granules, highlighting the importance of using inert biodegradable substances for bioscaffold constructs in future studies. All materials were similarly encapsulated with a layer of poorly vascularized collagen. Porcine dermis, sham dissections, and the STAR scaffolds received the best scores for collagen deposition and encapsulation. Conclusion: Implantation studies in an in-vivo pig model revealed that polypropylene/silicone-based STAR implants confer no advantage over expanded polytetrafluoroethylene, the current gold standard for soft tissue reconstruction. Future testing of less reactive, biodegradable materials for STAR constructs such as hyaluronic acid may show an improvement over current soft tissue implants.