Design, Synthesis And Characterization Of Series Of Biomedical Polymer Materials

Human health and longevity depend on the development of medicine. In recent years, biomedical polymer materials and products have increasingly found clinical application owing to their excellent performances such as unique biological histocompatibility, and non-toxicity with the development of biomedical engineering, materials science and biotechnology. In this paper, we synthesized two classes of biomedical materials, and the specific studies were summarized as follows.1. A series of nanohybrid hydrogels were designed and developed based on a hydrogen bond self-assembly of poly (methacylic acid) networks (PMAA) and carboxyl-functionalized multi-walled carbon nanotubes (MWCNT-COOH). The structure, morphology and mechanical performance of nanohybrid hydrogels were obtained through FT-IR,ESEM,TEM,DMA etc. The results showed that the MWCNT-COOH was closely covered by PMAA network in the hybrid hydrogel and well dispered in the matrix on the basis of hydrogen bond interactions. The introduction of MWCNT-COOH caused the swelling rate to be significantly higher than that of pure PMAA hydrogel. The nanohybrid hydrogels showed low micropore densities and larger mesh sizes with an increase in MWCNT-COOH contents, which govern the pH response to some extent. Increasing pH values caused equilibrium swelling ratios and accumulative release to be elevated. Swelling was enhanced sharply and mechanical properties distinctly declined. Particularly, the hydrogels containing 10 wt% MWCNT-COOH was observed to collapse at pore walls because of large holes, which was believed to be responsible for high swelling. Theophylline was used as a model drug for the release studies to observe the effect of different MWCNT-COOH concentrations and pH values on drug release. So PMAA/MWCNT-COOH hybrid hydrogel was a potential carrier of controlling drug release materials.2. A series of novel dendritic polyurethane (PU) scaffolds were designed and prepared on the basis of a triethanolamine-hyperbranched carboxyl-terminated poly (butadiene-co-acrylonitrile) (f-CTBN), poly (ethylene glycol) (PEG) and diisocyanate curing agents by a coupling or step-by-step synthetical method. The hydrolytic degradation, mechanical properties, blood compatibility and cytotoxicity of the bicomponent dendritic f-CTBN/PEG PU materials were scrutinized. The structure and surface morphologies of PU residues and degraded polymers at different time periods of hydrolysis were characterized by FT-IR and SEM. The experimental results indicated that the mass loss of samples is enhanced with increasing PEG concentrations and its molecular weight (mol. wt. or Mn), and degradation residues exhibit increasing porosity with time period of hydrolysis. The in vitro blood compatibility and methyl tretrazolium cytotoxicity as well as hydrophilicity investigations elicited that the mol. wt. of PEG, component ratios of f-CTBN to PEG and different curing agents have important influence on hemolytic activity, platelet activation, dynamic coagulation and PT, APTT, PRT, cell relative viability or growth rate, cell cycle or apoptosis as well as swelling and contact angles etc. The tensile stress-strain investigations showed that the highly crosslinked architecture offers the high tensile strength (more than 18 MPa), Young's modulus (more than 40 MPa) and reasonable elongation at break. Therefore, these PU materials have a great application prospect as biomedical polymer materials and will have huge application potentials in the biomedical field, especially in the intervention clinics and medical film products.