In order to improve the nonthr0mbogenicity of chitin, a new monomer, N, N-dimethyl(β-hydroxyethyloxyethyl) ammonium propanesulfonate (DHAPS) was designed, synthesized and grafted onto the chitin membrane by using hexamethylene diisocyanate (HDI) as a coupling agent. Surface analysis of the grafted membranes by ATR-FTIR and XPS confirms that DHAPS has been successfully grafted onto the membrane surface. The platelet resistant property of the grafted membranes was evaluated by a platelet-rich plasma adhesion method. The results showed that platelet-adhesive resistance of the modified membrane has been greatly improved. 相似文献
On the molecular level, it is believed that polymers containing zwitterionic structures should be compatible withblood. In this work polyurethane films were grafted with sulfobetaine by a three-step procedure. In the first step, the films'surfaces were treated with hexamethylene diisocyanate (HDI) in toluene at 50℃ in the presence of di-n-butyl tin dilaurate(DBTDL) as a catalyst. The extent of the reaction was monitored by ATR-IR spectra; a maximum number of free NCOgroups was obtained after a reaction time of 90 min. In the second step, the hydroxyl groups of N,N-dimethylethylethanolamine (DMEA) were allowed to react in toluene with NCO groups bound on the surface. In the thirdstep, sulfobetaines were formed on the surface through the ring-opening reaction between tertiary amine of DMEA and 1,3-propanesultone (PS). The surfaces of the films were characterized by ATR-IR and XPS showing that the grafted surfaceswere composed of sulfobetaine. The results of the contact angle measurement show that the surface was strongly hydrophilic.The platelet adhesion test demonstrated that the films grafted with sulfobetaine have excellent blood compatibility. 相似文献
Based on an in vitro test for an improvement of the blood compatibility of silicone rubber (SR) films by grafting O-butyrylchitosan (OBCS), OBCS was covalently immobilized onto SR film surface using the photosensitive hetero-bifunctional crosslinking reagent, 4-azidobenzoic acid, which was previously bonded to OBCS by reaction between an acid group of the crosslinking reagent and a free amino group of OBCS. Surface properties of SR film were investigated by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), electron spectroscopy for chemical analysis (ESCA) and the water contact angle measurements. The blood compatibility of SR film was evaluated by platelet rich plasma (PRP) contacting experiments and the results were observed by scanning electron microscopy (SEM). The state of platelet adhesion was described. The suitable modifications could be carried out to tailor SR films biomaterial to meet the specific needs of different biomedical applications. These results suggest that the blood compatible of SR films/OBCS films show their suitability as potential biomaterials. 相似文献
A new economic and convenient method to modify the surface of microporous polypropylene (PP) membranes with phospholipid polymer was given. The process included the photo-irradiated graft polymerization of N,N-dimethylaminoethyl methacrylate (DMAEMA) and the ring-opening reaction of the grafted polyDMAEMA with 2-alkyloxy-2-oxide-1,3,2-dioxo-phospholanes (AOP). Four AOPs, whose alkyloxy groups consisted of dodecyl, tetradecyl,hexadecyl and octadecyl moieties, were used to convert the grafted polyDMAEMA to phospholipidpolymers. FT-IR spectra confirmed the chemical change of membrane surface. Platelets adhesion experiment indicated that PP membrane with excellent blood compatible surface could be fabricated by this method. 相似文献
The surface of polyethersulfone (PES) membrane was modified by blending triblock copolymers of methoxyl poly(ethylene glycol)-polyurethane-methoxyl poly(ethylene glycol) (mPEG-PU-mPEG), which were synthesized through solution polymerization with mPEG Mns of 500 and 2000, respectively. The PES and PES/mPEG-PU-mPEG blended membranes were prepared through spin coating coupled with liquid-liquid phase separation. FTIR and (1)H NMR analysis confirmed that the triblock copolymers were successfully synthesized. The functional groups and morphologies of the membranes were studied by ATR-FTIR and SEM, respectively. It was found that the triblock copolymers were blended into PES membranes successfully, and the morphologies of the blended membranes were somewhat different from PES membrane. The water contact angles and platelet adhesion were decreased after blending mPEG-PU-mPEG into PES membranes. Meanwhile, the activated partial thromboplastin time (APTT) for the blended membranes increased. The anti-protein-fouling property and permeation property of the blended membranes improved obviously. SEM observation and 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay proved the surfaces of the blended membranes promoted human hepatocytes adhesion and proliferation better than PES membrane. 相似文献
To improve interfacial phenomena of poly(dimethylsiloxane) (PDMS) as biomaterials, well-defined triblock copolymers were prepared as coating materials by reversible addition-fragmentation chain transfer (RAFT) controlled polymerization. Hydroxy-terminated poly(vinylmethylsiloxane-co-dimethylsiloxane) (HO–PVlDmMS–OH) was synthesized by ring-opening polymerization. The copolymerization ratio of vinylmethylsiloxane to dimethylsiloxane was 1/9. The molecular weight of HO–PVlDmMS–OH ranged from (1.43 to 4.44) × 104, and their molecular weight distribution (Mw/Mn) as determined by size-exclusion chromatography equipped with multiangle laser light scattering (SEC-MALS) was 1.16. 4-Cyanopentanoic acid dithiobenzoate was reacted with HO–PVlDmMS–OH to obtain macromolecular chain transfer agents (macro-CTA). 2-Methacryloyloxyethyl phosphorylcholine (MPC) was polymerized with macro-CTAs. The gel-permeation chromatography (GPC) chart of synthesized polymers was a single peak and Mw/Mn was relatively narrow (1.3–1.6). Then the poly(MPC) (PMPC)–PVlDmMS–PMPC triblock copolymers were synthesized. The molecular weight of PMPC in a triblock copolymer was easily controllable by changing the polymerization time or the composition of the macro-CTA to a monomer in the feed. The synthesized block copolymers were slightly soluble in water and extremely soluble in ethanol and 2-propanol.
Surface modification was performed via hydrosilylation. The block copolymer was coated on the PDMS film whose surface was pretreated with poly(hydromethylsiloxane). The surface wettability and lubrication of the PDMS film were effectively improved by immobilization with the block copolymers. In addition, the number of adherent platelets from human platelet-rich plasma (PRP) was dramatically reduced by surface modification. Particularly, the triblock copolymer having a high composition ratio of MPC units to silicone units was effective in improving the surface properties of PDMS.
By selective decomposition of the Si–H bond at the surface of the PDMS substrate by irradiation with UV light, the coating region of the triblock copolymer was easily controlled, resulting in the fabrication of micropatterns. On the surface, albumin adsorption was well manipulated. 相似文献
Alginate, a natural polysaccharide that has shown great potential as a cell scaffold for the regeneration of many tissues, has only been nominally explored as an electrospun biomaterial due to cytotoxic chemicals that have typically been used during nanofiber formation and crosslinking. Alginate cannot be electrospun by itself and is often co‐spun with poly(ethylene oxide) (PEO). In this work, a cell adhesive peptide (GRGDSP) modified alginate (RA) and unmodified alginate (UA) were blended with PEO at different concentrations and blending ratios, and then electrospun to prepare uniform nanofibers. The ability of electrospun RA scaffolds to support human dermal fibroblast cell attachment, spreading, and subsequent proliferation was greatly enhanced on the adhesion ligand‐modified nanofibers, demonstrating the promise of this electrospun polysaccharide material with defined nanoscale architecture and cell adhesive properties for tissue regeneration applications.