Development of a Hydroxyapatite-Poly (d, l-lactide-co-glycolide) Infiltrated Carbon Foam for Orthopedic Applications

Reticulated vitreous carbon (RVC) foams are of interest in orthopedic applications due to their porous, honeycomb-like structure, biocompatibility, and bio-inert nature. Despite these desirable properties, RVC foams lack the strength necessary for orthopedic applications. Specifically, orthopedic biomaterials, whether bone scaffolds, plates or screws, must be able to withstand normal bone tissue loading at the time of implantation. This manuscript focuses on developing a composite RVC foam infiltrated with a hydroxyapatite (HA)-reinforced poly(d,l-lactide-co-glycolide) (PLGA) polymer. The HA/PLGA filler is envisioned to increase initial RVC foam mechanical stability while enabling osteoblasts to invade and deposit new tissue within the foam as the filler resorbs, providing long-term strength and osseointegration. Herein, a facile processing technique is developed which results in HA/PLGA-infused RVC foams with good internal interfacial bonding and increased modulus and strength relative to pure RVC foams. As anticipated, in vitro hydrolytic degradation studies indicate that the porous network of the RVC foam becomes progressively more accessible as the PLGA filler degrades and that the RVC foam may support improved structural integrity of the resorbing filler. Initial cell studies also demonstrate that this material system allows for robust osteoblast adhesion. These results indicate the proposed composites warrant further investigation for orthopedic applications

Human Cadaveric Donor Cornea Derived Extra Cellular Matrix Microparticles for Minimally Invasive Healing/Regeneration of Corneal Wounds

Biological materials derived from extracellular matrix (ECM) proteins have garnered interest as their composition is very similar to that of native tissue. Herein, we report the use of human cornea derived decellularized ECM (dECM) microparticles dispersed in human fibrin sealant as an accessible therapeutic alternative for corneal anterior stromal reconstruction. dECM microparticles had good particle size distribution (≤10 µm) and retained the majority of corneal ECM components found in native tissue. Fibrin–dECM hydrogels exhibited compressive modulus of 70.83 ± 9.17 kPa matching that of native tissue, maximum burst pressure of 34.3 ± 3.7 kPa, and demonstrated a short crosslinking time of ~17 min. The fibrin–dECM hydrogels were found to be biodegradable, cytocompatible, non-mutagenic, non-sensitive, non-irritant, and supported the growth and maintained the phenotype of encapsulated human corneal stem cells (hCSCs) in vitro. In a rabbit model of anterior lamellar keratectomy, fibrin–dECM bio-adhesives promoted corneal re-epithelialization within 14 days, induced stromal tissue repair, and displayed integration with corneal tissues in vivo. Overall, our results suggest that the incorporation of cornea tissue-derived ECM microparticles in fibrin hydrogels is non-toxic, safe, and shows tremendous promise as a minimally invasive therapeutic approach for the treatment of superficial corneal epithelial wounds and anterior stromal injuries