Protein adsorption is considered to be the most important factor of the interaction between polymeric biomaterials and body fluids or tissues. Water-mediated hydrophobic and hydration forces as well as electrostatic interactions are believed to be the major factors of protein adsorption. A systematic analysis of various monolayer systems has resulted in general guidelines, the so-called "Whitesides rules". These concepts have been successfully applied for designing various protein-resistant surfaces and are being studied to expand the understanding of protein-material interactions beyond existing limitations. Theories on the mechanisms of protein adsorption are constantly being improved due to the fast-developing analytical technologies. This Review is aimed at improving these empirical guidelines with regard to present theoretical and analytical advances. Current analytical methods to test mechanistic hypotheses and theories of protein-surface interactions will be discussed. Special focus will be given to state-of-the-art bioinert and biospecific coatings and their applications in biomedicine.

Protein interactions with polymer coatings and biomaterials.

A Multifunctional Pro-Healing Zwitterionic Hydrogel for Simultaneous Optical Monitoring of pH and Glucose in Diabetic Wound Treatment

This focused review addresses the fundamental development of nonfouling zwitterionic poly(sulfobetaine methacrylate) (polySBMA) coatings on a wide range of interfaces and membranes in our laboratory for use in the development of hemocompatible medical devices. The molecular designs of zwitterionic interfaces (for example, surface packing density, grafting coverage, polymer chain conformation and chemistry) as well as the evolution of ‘intelligent’ interfaces are scrutinized and discussed. Correlations between polymeric membrane surface modification methods, such as thermal- and plasma-induced polymerizations, the conformation of grafted polySBMA chains and hemocompatibility features, are also delineated. Fundamental development of nonfouling zwitterionic poly(sulfobetaine methacrylate) (polySBMA) coatings on a wide range of interfaces and membranes for use in the development of hemocompatible medical devices was discussed. The molecular designs of zwitterionic interfaces as well as the evolution of ‘intelligent’ interfaces and correlations between zwitterionic polymeric membrane surface modifications are scrutinized and delineated.

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Hemocompatibility of zwitterionic interfaces and membranes

Biomimetic and bioinspired membranes: Preparation and application

A series of novel polyurethane/siloxane-based wound dressing membranes was prepared through sol–gel reaction of methoxysilane end-functionalized urethane prepolymers composed of castor oil and rici...

Stimulation of Wound Healing by Electroactive, Antibacterial, and Antioxidant Polyurethane/Siloxane Dressing Membranes: In Vitro and in Vivo Evaluations

Development of bioinert membranes to prevent blood clotting, tissue adhesion, and bacterial attachment is important for the wound healing process. In this work, two wound-contacting membranes of expanded poly(tetrafluoroethylene) (ePTFE) grafted with zwitterionic poly(sulfobetaine methacrylate) (PSBMA) and hydrophilic poly(ethylene glycol) methacrylate (PEGMA) via atmospheric plasma-induced surface copolymerization were studied. The surface grafting chemical structure, hydrophilicity, and hydration capability of the membranes were determined to illustrate the correlations between bioadhesive properties and wound recovery of PEGylated and zwitterionic ePTFE membranes. Bioadhesive properties of the membranes were evaluated by the plasma protein adsorption, platelet activation, blood cell hemolysis, tissue cell adhesion, and bacterial attachment. It was found that the zwitterionic PSBMA-grafted ePTFE membrane presented high hydration capability and exhibited the best nonbioadhesive character in contact with ...

Surface Zwitterionization of Expanded Poly(tetrafluoroethylene) Membranes via Atmospheric Plasma-Induced Polymerization for Enhanced Skin Wound Healing

Biofouling has long been a problem for biomaterials, so being able to control the fouling on the surface of a biomaterial would be ideal. In this study a copolymer system was designed comprising three moieties: an epoxy containing group, glycidyl methacrylate (GMA); a thermoresponsive segment, N-isopropylacrylamide (NIPAAm); and an antifouling zwitterionic unit, sulfobetaine methacrylate (SBMA). The copolymers (pGSN), synthesized via free radical polymerization with these 3 moieties, were then grafted onto polydimethylsiloxane (PDMS). The presence of a critical temperature for both the copolymers and the coated PDMS was evidenced by particle size and contact angle measurements. The coated PDMS exhibited controllable temperature-dependent antifouling behaviors and stimuli-responsive phase characteristics in the presence of salts. The interactions of the coated PDMS with biomolecules were tested via attachment of fibrinogen protein, platelets, human whole blood, and tumor cells (HT1080). The attachment and detachment of these biomolecules were studied at different temperatures. Exposed hydrophobic domains of thermoresponsive NIPAAm-rich pGSN containing NIPAAm at 56 mol% generally allows molecular and cellular attachment on the PDMS surface at 37 °C. On the other hand, the coated PDMS with a relatively high content of SBMA (>41 mol%) in the copolymer started to exhibit fouling resistance and lower the thermoresponsive properties. Interestingly, the incorporation of zwitterionic SBMA units into the copolymers was found to accelerate the hydration of the PDMS surfaces and resulted in biomolecular and cellular detachment at 25 °C, which is comparable to the detachment at 4 °C. This modified surface behavior is found to be consistent through all biofouling tests.

Sheng-Han Chen

Papers

Surface Zwitterionization of Expanded Poly(tetrafluoroethylene) Membranes via Atmospheric Plasma-Induced Polymerization for Enhanced Skin Wound Healing

Temperature-triggered attachment and detachment of general human bio-foulants on zwitterionic polydimethylsiloxane.