Discipline: Chemistry and Chemical Sciences
Subcategory: Chemistry (not Biochemistry)
Ruth Anyaeche - Fisk Univeristy
Co-Author(s): Ryan Gray, Virginal Tech University Natalie Arnett PHD, Associate Professor of Chemistry Chair, Department of Life and Physical Fisk University
The mechanism by which cells attach to biomaterials and scaffolds for tissue engineering is critically important for successful tissue regeneration. The most commonly used scaffold polymer in tissue engineering is the poly (lactic-co- glycolic acid) (PLGA). PLGA copolymers are made up of various molar ratios of glycolic acid and lactic acid. Studies have shown that PLGA copolymers have excellent biodegradability and biocompatibility. Although PLGA copolymers biodegrade over longer periods of time compared to its constituent polymers like poly (glycolic acid (PGA) and poly (lactic acid) (PLA), the degradative properties of these copolymers are primarily dependent on molar ratio of PGA to PLA (which rapidly undergo hydrolysis). Improvements to the degradative properties of PLGA’s constituents have been investigated through polymer blending with various polymers including poly (ε caprolactone) PCL. poly (mannitol sebacate) (PMS) is a polymer with great biocompatible features but its rapid degradation time limits its application in tissue engineering. poly (xylitol sebacate) PXS has better elastic properties than PMS but PMS has better tensile strength. In tissue engineering polymers are required to display the properties of the tissue they are going to assist in repairing. Initially it was thought that blending PMS with PGA, PLA, and PCL through solution blending would improve PMS degradation properties for tissue engineering. In this research, the effects of mannitol and xylitol molar concentration in poly (mannitol xylitol sebacate) (PMXS) copolymers was investigated. PMXS copolymers was synthesized by melt polymerization of mannitol and xylitol with sebacic acid. Improvements to the degradative and mechanical properties PMXS copolymer through varying the molar ratio of mannitol to xylitol will be the focus of this research. The characterization of these polymers was characterized using proton NMR, IR, DSC and DGA. The properties of PMXS copolymers as a function of mannitol to xylitol concentration were accessed in this research. Melt polymerization for 10 hrs. was used to prepare the copolymers since high molecular weight were shown to be achieved at this reaction time. The molar ratios of mannitol to xylitol investigated to determine the effect monomer concentration on the PMXS properties were 100/0, 80/20, 60/40, 50/50, 40/60, 20/80, and 0/100. Changes to the physical properties were observed as the concentration of mannitol to xylitol was increased in the polymer. As the concentration of mannitol was increased the polymer had an increase in the hardness and rubbery character of the polymer also increase up to 50 mol%. Further increases in mannitol concentration (>50 mol%) resulted in polymers becoming slightly softer and sticker as observed in the PMS homopolymer.Not Submitted
Funder Acknowledgement(s): NSF
Faculty Advisor: Natalie Arnett PhD, email@example.com
Role: Investigating the effects and increasing the molecular weight of PMXS by synthesizing mannitol, xylitol sebacate (PMXS) copolymer. PMXS copolymers was synthesized by melt polymerization of mannitol and xylitol with sebacic acid for 10 and 24 hours since high molecular weight were shown to be achieved at this reaction time. Improvements to the degradative and mechanical properties PMXS copolymer through varying The characterization of these polymers was characterized using proton NMR, IR, DSC and DGA.