The addition of the amniotic membrane to mineralized collagen scaffolds for immunomodulatory bone regeneration

Statement of Purpose: Cranio-maxillofacial (CMF) defects often are comprised of critical sized bone defects that will not heal without surgical intervention. Examples of CMF defects extend from birth defects, to post-oncologic treatment and high-energy impacts, with billions spent on repair. Due to the overwhelmingly large portion of bone missing in these defects, there is a high chance for infection and a high probability of chronic inflammation occurring. This leaves a crucial niche for developing a bone regenerative material that can modulate the immune response to aid healing. Efforts in our lab have recently developed a mineralized collagen-GAG scaffold to induce MSC osteogenic differentiation and CMF bone regeneration in the absence of traditional pro-osteogenic signals [1]. Here we describe the incorporation of the amniotic membrane, known for its anti-inflammatory, anti-scarring, and anti-microbial properties, into mineralized collagen scaffolds for immunomodulatory applications. We examine the mechanical properties and pore size upon the addition of the amniotic membrane, as well as the response of porcine adipose derived stem cells (pASCs) seeded on these scaffolds in both normal media and high inflammatory media. We evaluate the metabolic activity, cell number, gene expression, protein activity, and mineralization of these scaffolds in vitro. Current work explores the bacterial response on the amniotic membrane and macrophage polarization.