This award by the Biomaterials program in the Division of Materials Research to the Texas Engineering Experiment Station (TAMU) is to develop a series of collagen-mimetic polyurethanes that combine the strength and tunability of synthetic elastomers with the cell-responsive degradation of native collagen. Tissue engineering has emerged as a promising alternative for ligament reconstruction when traditional transplants are unavailable or fail. Success of ligament tissue engineering strategies depend upon 1) the construct retaining sufficient mechanical properties to stabilize the joint throughout remodeling; and 2) the new tissue receiving the appropriate level of load for directed collagenous organization/alignment. It continues to be difficult to both predict and tailor the non-specific hydrolysis of current synthetic biomaterials; whereas, natural materials are limited by mass-production, variability, or lack the tensile properties necessary for ligament applications. New biomaterials are needed that can meet the complex design criteria necessary for ligament repair. By yielding control of scaffold degradation to the cell, the scaffold will degrade at a rate that best promotes tissue formation and organization. The proposed studies will provide the synthetic routes and predictive structure-property relationships necessary to use these biomaterials in tissue engineering scaffolds. In addition, systematic study of these novel polyurethanes will be carried out to delineate individual effects of degradation and mechanical load on material properties. The ability to predict how the tensile properties of a scaffold change during degradation and how these processes are influenced by loading is critical in the rational design of ligament scaffolds. On a grander scale, the structural models and methodology developed in this research will also be applicable to other clinical specialties in which biodegradation shows promise in improving patient care (e.g. cardiovascular tissue engineering, biodegradable stents, fixation devices, etc.).
By this award, the PI will study the synthetic routes and predictive structure-property relationships necessary to use collagen-like polyurethanes that combine the strength and tunability of synthetic polyurethane with the cell-responsive degradation of native collagen. in tissue engineering scaffolds. The proposed research will be used as an educational and training tool to (1) increase the exposure to exciting biomedical research, and (2) prepare students to pursue careers in science and engineering. In addition, the PI plan to broaden the participation of undergraduate students by recruiting these students for summer internships from Prairie View A&M University, a Historically Black University. The interdisciplinary and multi-scale nature of the proposed research will provide a rigorous training ground to prepare both undergraduate and graduate students for careers in academia, national laboratories, or industry. The research program will be used to foster critical thinking and equip students with state-of-the-art experimental skills in chemistry, polymer science and engineering. In addition, reports, theses, manuscript drafting, presentations at weekly group meetings, and opportunities to present at regional and national meetings will foster effective communication skills. Finally, the principles and results coming out of this research will be incorporated into courses taught by the PI to educate students and encourage interest in biomaterial research.
Tissue engineering has emerged as a promising alternative for ligament reconstruction when traditional transplants are unavailable or fail. Success of ligament tissue engineering strategies depend upon (1) the construct retaining sufficient mechanical properties to stabilize the joint throughout remodeling; (2) the new tissue receiving the appropriate level of load for directed collagenous organization/alignment. It continues to be difficult to both predict and tailor the degradation of current synthetic biomaterials; whereas, natural materials are limited by mass-production, variability, or lack the tensile properties necessary for ligament applications. Therefore, new biomaterials are needed that can meet the complex design criteria necessary for ligament repair. We developed a series of collagen-mimetic polyurethanes that combine the strength and tunability of synthetic elastomers with the cell-responsive degradation of native collagen. We hypothesize that by yielding control of scaffold degradation to the cell, the scaffold will degrade at a rate that best promotes tissue formation and organization. Intellectual Merit: In this work, we developed the synthetic methods and predictive structure-property relationships necessary to use the proposed biomaterials in tissue engineering scaffolds. These new hybrid materials combine what the body knows how to do with natural materials with the mechanical properties, availability and tunability of synthetic materials. We have demonstrated that we can change the mechanical properties and degradation rate through controlled manipulation of the polymer chemistry. The hybrid nature of the material allows for exceptionally tough elastomers with the same cell-responsive degradation of native collagen. Beyond ligament reconstruction, the structural models and methodology developed in this research will be applicable to other clinical specialties in which cell-responsive degradation shows promise in improving patient care (e.g. cardiovascular tissue engineering, biodegradable stents, fixation devices). Broader Impacts: The research was also used as an educational and training tool to (1) increase the exposure to exciting biomedical research and (2) prepare students to pursue careers in science and engineering. The interdisciplinary and multi-scale nature of the proposed research provided a rigorous training ground to prepare both undergraduate and graduate students for careers in academia, national laboratories, and industry. The research program fostered critical thinking and equipped students with state-of-the-art experimental skills in chemistry, polymer science and engineering. The principles and results of this research were also incorporated into courses taught by the PI to educate students and encourage interest in biomaterial research. Finally, we initiated a regional biomaterials conference to increase student exposure to exciting biomaterials research which has become an annual event in Texas.
