Biocompatibility, and adhesion

Biocompatibility and adhesion of different cells to the polystyrene surface is significantly enhanced by the formation of amine groups on the surfaee during treatment in NH3 plasma. Similarly, the amine groups ereated inNHs plasma on the surfaee of PTFE provide adhesion of collagen. 

In a simple approach, monomers of the guest polymer are first impregnated into a preformed porous silicate film, and subsequently polymerization is initiated either by a free radical initiator (UV, peroxides), by thermal treatment, or by electrochemical means. On the positive side, this procedure is favorable for the incorporation of linear polymers in silicates, but on the downside, some of the major advantages of composites, such as biocompatibility and adhesion to the substrate, are lost. The polymerization of organic moieties within the interconnected pores of the organic material can be carried out by two general methods that are addressed in the following text. 

The impact of energetic ions on polymeric materials is very important for the modification of the first few nanometres of the polymer surface. This treatment has disturbing and damaging effects on surfaces, but is also sometimes used to probe surface properties. Bombardment with low-energy ions alters the structure, morphology, and chemical properties of materials. The main properties that can be modified using this procedure are rheological properties, electrical conductivity, optical and mechanical properties, surface texture, crystalline state, biocompatibility, and adhesive and surface properties. 

Schiraldi et al. [64] have developed this kind of material by combining silica particles and pHEMA. pHEMA is a biocompatible hydrogel that has been widely studied in the past decades due to its chemical-physical structure and mechanical properties. It has been widely used in ophthalmic prostheses (contact or intraocular lenses), vascular prostheses, drug delivery systems and soft-tissue replacement [65]. These authors have shown that by incorporating silica nanoparticles, the resulting hybrid material is highly biocompatible and promotes bone cell adhesion and proliferation of bone cells seeded on it.1 ... 

Polymer-based pH sensors are not suitable for continuous in-vivo measurements due to the poor biocompatibility of plasticizers used in the polymer membrane. To minimize such a problem, surface treatment or using a reduced amount of plasticizers has been proposed [71]. In order to improve stability and adhesion, polyurethane has been used as an alternative to PVC membranes in the construction of pH sensing membranes [72, 73],... 

In a previous section, the effect of plasma on PVA surface for pervaporation processes was also mentioned. In fact, plasma treatment is a surface-modification method to control the hydrophilicity-hydrophobicity balance of polymer materials in order to optimize their properties in various domains, such as adhesion, biocompatibility and membrane-separation techniques. Non-porous PVA membranes were prepared by the cast-evaporating method and covered with an allyl alcohol or acrylic acid plasma-polymerized layer the effect of plasma treatment on the increase of PVA membrane surface hydrophobicity was checked [37].The allyl alcohol plasma layer was weakly crosslinked, in contrast to the acrylic acid layer. The best results for the dehydration of ethanol were obtained using allyl alcohol treatment. The selectivity of treated membrane (H20 wt% in the pervaporate in the range 83-92 and a water selectivity, aH2o, of 250 at 25 °C) is higher than that of the non-treated one (aH2o = 19) as well as that of the acrylic acid treated membrane (aH2o = 22). 

Artificial materials designed for the biomedical use should be biocompatible, i.e. free of adverse effects on cells and tissues, such as cytotoxicity, immimogenicity, mutagenicity and carcinogenicity. Biocompatible materials can be constructed as bioinert, i.e. not allowing adsorption of proteins and adhesion of... 

Fluorourethanes are used in products ranging from hard, heat-resistant electrical components to biocompatible surgical adhesives. The properties of a specific flu-orourethane resin are determined by the raw materials and the manufacturing process used. 

Several techniques including corona discharge [1], plasma treatment [1,3,4], flame treatment [1], and irradiation with UV light in the presence of a UV sensitive gas [5-8] have been developed to modify the polymer surface. The principle of those surface treatment technologies is to introduce polar groups onto the polymer surface. This provides significant improvement of wettability, paintability, biocompatibility and also adhesion to other polymers or metals. 

Used to render surfaces biocompatible and resistant to protein adhesion copolymers with poly(propylene oxide) form thermoreversible gels for drug delivery... 

An ideal bond coat should have several characteristics that include uncompromised biocompatibility, good adhesion to both the metal substrate and the osseoconductive top coat, and a well-defined melting point to allow application of thermal spray technology. The adhesive function of the bond coat has been loosely compared to the action of a double-sided adhesive tape. 

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