Protein-polymer composites

Chew SY et al (2007) Aligned protein-polymer composite fibers enhance nerve regeneration a potential tissue-engineering platform. Adv Funct Mater 17(8) 1288-1296... 

Gill, I., and A. Ballesteros. 2000b. Bioencapsulation within synthetic polymers (part 2) Non-sol-gel protein-polymer composites. Trends in... 

In this chapter, we overview some of the more advanced and promising protein immobilization technologies that have become available in the last decade, especially the fabrication of organized thin film architectures, sol-gel encapsulation, crosslinked crystals, and protein-polymer composites. The current status and applicability of these methods in the catalyst, sensor, and diagnostics arenas, as well as prospective applications and future developments are discussed. 

Protein polymers based on Lys-25 were prepared by recombinant DNA (rDNA) technology and bacterial protein expression. The main advantage of this approach is the ability to directly produce high molecular weight polypeptides of exact amino acid sequence with high fidelity as required for this investigation. In contrast to conventional polymer synthesis, protein biosynthesis proceeds with near-absolute control of macromolecular architecture, i.e., size, composition, sequence, topology, and stereochemistry. Biosynthetic polyfa-amino acids) can be considered as model uniform polymers and may possess unique structures and, hence, materials properties, as a consequence of their sequence specificity [11]. Protein biosynthesis affords an opportunity to completely specify the primary structure of the polypeptide repeat and analyze the effect of sequence and structural uniformity on the properties of the protein network. 

Mass spectra are used to determine molecular weights and molecular composition (from the parent or molecular ion) and to obtain structural information from the fragmentation of the molecular ion into daughter ions. Electrospray ionization (ESI-MS) and matrix-assisted laser desorption ionization (MALDI-MS) mass spectroscopy can be used to obtain structural information about macromolecules, including proteins, polymers, and drug-DNA complexes. 

Cuno Cellulose/acylic polymer composite Protein A/G, benzami-dine... 

However, to make such a therapy reality, concerns over cell viability inside the implantable device have to be adequately addressed. The implant s polymer composition and morphology would have to be optimized in order to maximize the life-span of the cells and to minimize host immune responses. The vascularization of the implant would be another determinant that plays an important role regarding cell viability because it enables the implant to receive nutrients necessary for their survival, to eliminate metabolic by-products and to provide the systemic entrance of therapeutic proteins. 

Polymer adsorption has also been adapted to QCM sensing whereby biofunctional thin films are adsorbed on the crystal surface with non-specific binding controlled by tuning of polymer composition. This approach proved successful as applied to carbohydrate-protein interaction by Matsuura et al. through adsorption of lactose bearing amphiphilic polymers on hydrophobic surfaces which then showed RCA12o and peanut lectin (PNA) affinity [33]. Carbohydrate surfaces prepared by photo insertion into an adsorbed polymer were tested by QCM and showed the predicted affinities [34] while in another example a covalently bound glycopolymer demonstrated Concanavalin A detection ability [35]. 

The enzymatic activity of a-chymotiypsin was evaluated in composites of poly(methyl metacrilate) with different carbon materials [91] demonstrating that the incorporation of SWCNTs into enzyme-polymer composites results in active and stable polymeric films. The release of the protein from the composite was evaluated measuring the enzymatic activity in the supernatant in contact with the composite. The results showed that in the case of SWCNTs the leaching of the protein from the composite was lower. This fact was attributed to the imion of the protein to the CNTs. The effect of other polymers such as polystyrene and poly(lactic acid) was also analyzed and the leaching of the protein was significant in the absence of SWCNTs. Only the hydrophobic ones (poly(methyl metacrilate)... 

Water / protein (polymer) mixtures are also considered (5.7). The local composition around a protein (or polymer) molecule is examined, and its connection to the protein / water and protein / protein intermolecular interactions is scrutinized. 

Figure 2. Predicted protein partition coefficient versus PEG molecular weight for lysozyme, chymotrypsin, albumin and catalase. Dextran molecular weight is 23,000 and polymer composition is PEG 6% Dx 8%.

Materials of interest include metals and alloys, semiconductors, ceramics and ionic solids, concrete, dielectrics and polymers, composites, biological materials including proteins and enzymes, membranes and coatings, aqueous and nonaqueous solvents and solutions, molten salts, catalytic materials, colloids, surfactants and inhibitors, and emulsions and foams. 

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