To obtain an aqueous polymer system with good antibacterial properties, a series of gemini waterborne polyurethanes （GWPU） were designed and synthesized using isophorone diisocyanate, polyoxytetramethylene glycol, poly（ethylene glycol）, L-lysine and a novel L-lysine-derivatized diamine containing gemini quaternary ammonium salt （EG12） without any other organic agent involved in the whole synthetic process. EG12 was first synthesized and characterized with proton nuclear mag- netic resonance spectra and mass spectra. The antibacterial activities of EG12 and GWPU were evaluated by quanti- fying the minimal inhibitory concentration. The results indicated that the gemini quaternary ammonium chain extender EG12 and GWPU showed excellent antibacterial activity against a broad spectrum of gram-positive and gram-negative bacteria. This work provides a new and facile approach to prepare novel antibacterial materials, which could be applied as coatings in various fields to prevent microbial contamination.
Yi ZhangYifan LiJiehua LiYunlong GaoHong TanKunjie WangJianshu LiQiang Fu
To further improve the biocompatibility of polyurethanes,a new lysine 2-(2-aminoethoxy)ethanol phosphatidylcholine(LAPC)is synthesized to use as chain extender for preparing a series of phosphatidylcholine polyurethanes(PCPUs).Poly(e-caprolactone)(PCL)and poly(ethylene glycol)(PEG)are used as soft segments,and L-lysine ethyl ester diisocyanate(LDI),LAPC and L-lysine are used as hard segments.The obtained PCPUs exhibit appropriate mechanical properties with break elongation of 1000–1700%,tensile strength of 7–22 MPa,and relatively high elastic modulus of 11–18 MPa,which could admirably satisfy the requirement for soft tissue engineering scaffolds.The phosphatidylcholine structures can increase the hydrophilicity of PCPU surfaces,which effectively reduce protein adsorption and platelet adhesion while promoting the cell proliferation.In addition,the LAPC chain extender,PCPU films and ultimate degradation products of PCPUs are proved to be nontoxic in cytotoxicity test.More interestingly,the cytokine release test of macrophages manifests that both LAPC and PCPU degradation products could effectively improve the proliferation of macrophages and induce them into a wound-healing phenotype.Thus,the obtained PCPUs have greatly potential applications of soft tissue engineering scaffolds for tissue repair and wound healing.
Hongye HaoYa DengYingke WuSiyuan LiuWeiwei LinJiehua LiFeng Luo
In this study, to improve hemocompatibility of biomedical materials, a waterborne polyurethane （WPU）haepafin release coating system （WPU/heparin） is fabricated via simply blending biodegradable WPU emulsions with heparin aqueous solutions. The surface compositions and hydrophilicity of these WPU/heparin blend coatings are characterized by attenuated total reflectance infrared spectroscopy （ATR-FTIR） and water contact angle measurements. These WPU/heparin blend coatings show effectively controlled release of heparin, as determined by the toluidine blue method. Furthermore, the biocompatibility and anticoagulant activity of these blend coatings are evaluated based on the protein adsorption, platelet adhesion, activated partial thromboplastin time （APTT）, thrombin time （TT）, hemolysis, and cytotoxicity. The results indicate that better hemocompatibility and cytocompatilibity are obtained due to blending heparin into this waterborne polyurethane. Thus, the WPU/heparin blend coating system is expected to be valuable for various biomedical applications.
Yuan-qing SongYun-long GaoZhi-cheng PanYi Zhang李洁华Kun-jie WangJian-shu Li谭鸿Qiang Fu
