Advisory Committee Chair
Advisory Committee Members
Date of Award
Degree Name by School
Doctor of Philosophy (PhD) School of Engineering
As human needs and purposes continue to evolve, it has become crucial that the materials with which we address these new applications and challenges evolve in stride. Specifically, the medical field’s need for advanced materials has led to the drive for biomaterial synthesis and processing methods which produce adaptable material characteristics to satisfy application specific needs. Research response has been to expand viable natural/ synthetic biomaterial resources, design innovative nanofiber fabrication techniques with high levels of productivity, ease of access, and cost efficiency, and explore crosslinking and surface treatments/modifications to enhance material characteristics for improved performance. This research employs select natural and synthetic biopolymers gelatin from cold water fish skin (FGEL) and polycaprolactone (PCL) along with the emerging high-throughput alternating field electrospinning (AFES, a.k.a. alternating current (AC) electrospinning) technique to produce blended nanofibrous materials with potential for biomedical applications. Gelatin and PCL are both commonly used as biomaterials because of their biocompatibility, biodegradability, and blending of these polymers mitigates the less desirable qualities of the respective polymers, allowing for tunability of the resulting material characteristics. FGEL 30wt% and PCL 20wt% precursors for AFES were successfully formed in a green single-solvent system of acetic acid and then blended in a wide range of functional compositional mass ratios 0.9:0.1-0.4:0.6 (FGEL:PCL). These precursor blends were found to be effective in the ranges of 300–800 mPa⋅s viscosities, 230–380 μS/cm electrical conductivities, and AFES process parameters of 28–30 kV, >30% humidity, and 22oC for successful fabrication of nanofibrous materials. These materials presented uniform, beadless nanofibers with average diameters of 200-750 nm. The nanofibrous mesh characteristics including morphology, porosity (84-97%), material wettability, PCL crystallinity/ orientation of PCL crystalline regions, and secondary structure of FGEL in asspun and thermally crosslinked materials were found to be heavily dependent on their composition and post-fabrication thermal treatment. Mechanical and degradation properties were no exception to the compositional and treatment influences, with UTS, elastic modulus, and strain at break within ranges of 100-400 kPa, 4.3-14.1 MPa, and 30-70%, respectively, and mass retention of the blended meshes in SBF environment up to 84% over 14 days exposure period. Initial in vitro studies of blended meshes indicated promising cellular attachment, spreading, proliferation, and metabolic activity encouraging for their use as potential biomaterials.
Lacy, Hannah A., "Investigation of Fish Gelatin/Polycaprolactone Nanofibrous Materials Alternating Field Electrospinning Fabrication and Characterization" (2023). All ETDs from UAB. 26.