Design,Synthesis And Properties Of A Series Of Neuroactive Biomaterials

Regenerating nerve by rationally-designed biomaterials is a pro mising solution to functional restoration of damaged nerves, a significant clinica l challenge. He re, we designed, synthesized, and characterized a series of neuroactive polymers with different functionalities, which had significant effects on their biointerfaces. The thesis includes following three parts:(1) Po ly(propylene sebacate)(PPS) and poly(sebacoyl diglyceride)(PSeD). Both are constructed from biocompatible mo ieties. PPS and PSe D have similar backbone, while PSe D contains numerous hydroxyl groups, which are absent in PPS. PPS and PSeD were synthesized via direct polyesterification and acid-induced epoxide ring-opening, respectively. NMR, IR and GPC were used to characterize their structures. TGA and DSC were used to characterize their therma l properties. Tensile tests were used to characterize their mechanical properties; Contact angle measurements were used to characterize their hydrophilicity. Then the interactions between materials and rental progenitor cells(RPCs) were investigated in details. The results showed that PPS without pendent hydroxyl groups was in favor of RPCs proliferation. PSe D with pendent hydroxyl groups was in favor of RPCs differentiation.(2) Acetylcholine based neuroactive polymers PSe D-Ach. PSe D-Ach was synthesized from PSe D in two steps. NMR, IR and GPC were used to characterize their structures. TGA and DSC were used to characterize their therma l properties. Simp le and cycle compression tests were used to characterize their mechanical properties. Contact angle measurements were used to characterize their hydrophilicity. Then the interactions between PSeD-Ach and PC12 cells were investigated in details comparing with four control conditions(unmodified PSe D, PSe D with free acetylcholine in culture mediu m, Poly(sebacoyl diglyceride)-Butyldimethylamine(PSe D-B) with similar structure including ammoniu m mo iety but wit hout acetyl group, and Laminin). The results showed that resembling to standard neuron culture material La minin, PSe D-Ach exh ibited stronger capabilities to promote the proliferation and neurite outgrowth of PC12 cells than PSe D with free acetylcholine in culture mediu m. PSe D-Ach induces much longer neurite of PC12 cells than the control polymer with similar a mmoniu m structure but with out acetyl groups revealing the important role of acetyl moiety. Furthermore, PSe D-Ach supported the adhesion, neurite sprouting and extending of rat dorsal root ganglions.(3) Biodegradable ammonium polycation. Polycations have been widely used in many biomedical fields including gene delivery, controlled release of growth factor, antimicrobial agents. We designed and synthesized a b iodegradable quaternary ammonium polycation by Menschutkin reaction between 1, 2- bis(chloroacetoxy) ethane and N,N,N',N'-tetra methyl-1,4-d ia minobutane at room temperature. The 1H NMR, 13 C NMR and FTIR spectra confirmed the structure of this polycation. Its thermal stability was evaluated by TGA. Its solubility in a series of solvents was investigated as well.