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J Biomed Mater Res A ; 93(1): 400-8, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19569222


A well-controlled biocompatible nonfouling surface is significant for biomedical requirements, especially for the improvement of biocompatibility. We demonstrate the low or nonbiofouling surfaces by coating hydrophobic-hydrophilic triblock copolymers of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) on the CH(3)-terminated self-assembled monolayer (SAM). Two types of copolymers are used to modify the surface, one with different PEO/PPO ratios ( approximately 20/80, 40/60, and 80/20, w/w) but the same PPO molecular weight ( approximately 2 k), the other with different copolymer MWs ( approximately 9, 11, and 15 k) but the same PEO/PPO ratio (80/20, w/w). In situ surface plasmon resonance (SPR) sensor is used to evaluate polymer adsorption on the SAMs and subsequent protein adsorption on the copolymer-treated surface. The effects of PEO-PPO-PEO molecular weight, PPO-to-PEO ratio, and ionic strength on protein adsorption from single protein solutions of fibrinogen, BSA, and complex mixed proteins are systematically investigated. A Pluronic F108 treated surface is highly resistant to nonspecific protein adsorption under the optimized conditions (MW of 15 k and PEO/PPO ratio of 80/20). This work demonstrates that the PEO-PPO-PEO polymer is able to achieve ultra low fouling surface via surface modification by controlling surface packing density of polymers (molecular weight, hydrophobic/hydrophilic ratio, and hydrophilic group coverage).

Proteínas Sanguíneas/metabolismo , Polietilenoglicóis/farmacologia , Propilenoglicóis/farmacologia , Ressonância de Plasmônio de Superfície/métodos , Adsorção/efeitos dos fármacos , Animais , Incrustação Biológica , Bovinos , Humanos , Peso Molecular , Poloxâmero/farmacologia , Soroalbumina Bovina/metabolismo , Propriedades de Superfície/efeitos dos fármacos
Biomacromolecules ; 10(8): 2092-100, 2009 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-19572632


Thermoresponsive statistical copolymers of zwitterionic sulfobetaine methacrylate (SBMA) and nonionic N-isopropylacrylamide (NIPAAm) were prepared with an average molecular weight of about 6.0 kDa via homogeneous free radical copolymerization. The aqueous solution properties of poly(SBMA-co-NIPAAm) were measured using a UV--visible spectrophotometer. The copolymers exhibited controllable lower and upper critical solution temperatures in aqueous solution and showed stimuli-responsive phase transition in the presence of salts. Regulated zwitterionic and nonionic molar mass ratios led to poly(SBMA-co-NIPAAm) copolymers having double-critical solution temperatures, where the water-insoluble polymer microdomains are generated by the zwitterionic copolymer region of polySBMA or nonionic copolymer region of polyNIPAAm depending on temperature. A high content of the nonionic polyNIPAAm in poly(SBMA-co-NIPAAm) exhibits nonionic aggregation at high temperatures due to the desolvation of polyNIPAAm, whereas relatively low content of polyNIPAAm in poly(SBMA-co-NIPAAm) exhibits zwitterionic aggregation at low temperatures due to the desolvation of polySBMA. Plasma protein adsorption on the surface coated with poly(SBMA-co-NIPAAm) was measured with a surface plasmon resonance (SPR) sensor. The copolymers containing polySBMA above 29 mol % showed extremely low protein adsorption and high anticoagulant activity in human blood plasma. The tunable and switchable thermoresponsive phase behavior of poly(SBMA-co-NIPAAm), as well as its high plasma protein adsorption resistance and anticoagulant activity, suggests a potential for blood-contacting applications.

Acrilamidas/química , Anticoagulantes/química , Materiais Biocompatíveis/química , Proteínas Sanguíneas/química , Polímeros/química , Ouro/química , Humanos , Transição de Fase , Ressonância de Plasmônio de Superfície , Propriedades de Superfície , Temperatura