Dissolvable Materials for Photochemical Tissue Bonding

This PHASE II two-year proposal is designed to expand upon the knowledge gained already in the PHASE I research regarding the development of rapid bioresorbable glasses to bring us to the making of prototype stents which would be ready for testing in animals and humans. Motivated by the success of PHASE I research, wherein several bioresorbable glasses in the Na2O-K2O-CaO-B2O3-P2O5 have been developed, our two-year PHASE II research program aims to optimize two or three specific compositions for dissolution behavior in simulated biofluid, hygroscopicity, mechanical ruggedness, and biocompatibility. The last topic will be studied by our research partner Penn State University. Phase separation behavior of the glass with heat-treatment, subsequent partial crystallization to develop glass-ceramic objects will be studied using XRD, TEM, and ionic leaching kinetics to follow preferential dissolution, if any. Additional modified chemical strengthening may be applied to improve the mechanical strength which would allow thinner but more rugged stent structures to be made with less material to be dissolved. Stents will be made either by a direct drawn tubing or by 3D additive manufacturing process. The latter process enables us to make complex shapes. Our Research Partner Co-PI, Professor James Adair, is a well-recognized bioglass researcher; being a protégé of the late Professor Larry Hench (often called the Father of bioglass). In that respect, Dr. Adair is one of the best to conduct transition research from our Phase I bioglasses to Phase II and moving over to Phase III with little to no learning curve in between. Penn State offers relevant biomedical engineering research experience and has world-class facilities. The biocompatibility testing procedures conducted by Penn State will be consistent with ISO 10993 standards. They will conduct In vitro evaluation using human cells to screen the glass compositions for cytotoxicity. Also, toxicity of polymeric scaffolds for glass will be examined.