Biocompatible Nanofibres

PPy offers tremendous technological potential, especially as electrodes for rechargeable batteries, sensors or supercapacitors. Since the electrochemical activity of PPy electrodes is proportional to the surface area, they must be processed to a shape in which the ratio of the surface area to volume or weight is high. This feature could be obtained via converting PPy to a fibre with small diameter, i.e., a nanofibre. In the nanoscale, the electrical conductivity of conductive polymers is increased. 

To date, the most successful method of producing nanofibres and nanoporous materials is through the process of electrospinning. The electrospinning process has gained much attention because it is an effective method of manufacturing ultrafine fibres or 

In this section, the preparation of electrically conductive polyvinyl acetate (PVA) nanofibres, using vapour phase chemical polymerisation of pyrrole onto the surface of the nanofibres, is investigated. PVA is highly biocompatible and nontoxic and was selected for this study because of its excellent chemical resistance and physical properties. 

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Update on Production of Metal/Polymer Nanocomposites and Biocompatible Nanofibres... 

A wide range of biopolymers, both namral and synthetic, have successfully been electrospun into nanofibres. They are different in terms of chemical natore, mechanical property, biocompatibility and bioresorbabUity. Some of the widely used biopolymers are discussed in this section. 

Poly(ethylene glycol) (PEG), also known as poly(ethylene oxide) (PEO), is a hydrophilic, biocompatible polyether. PEG usually refers to a material with relatively low molecular weight (e.g., several thousands), while PEO to a material with high molecular weight (e.g., over tens or hundreds of thousands). PEO is wafer soluble and therefore can be electrospun into nanofibres from its water solution (Deitzel et al., 2001). However, water solubility makes the material unstable in a biological environment. Consequently, PEO or PEG is usually used in combination with other natural (e.g., collagen, chitosan) or synthetic polymers (e.g., PLA) in blends or copolymers (Subramanian et al., 2005 Szentivanyi et al., 2009). 

An adequate treatment of the subject should involve a discussion of production materials. Thus we have referred to a large variety of materials (i.e., natural and synthetic polymers) for nanofibre fabrication, including the choice and use of them, and a description of how their properties influence processing parameters and properties (biocompatibility, cytotoxicity, etc.) of the product. 

The future trend of nanofibre development may include modification toward functionalisation of polymer nanofibres intended to improve their performance and function in biomedical applications. This purpose is achieved by incorporating such therapeutic agents as antibacterial agents and growth factors into the nanofibrous structures, so that the product will duly become capable of infection control, with improved biocompatibility and promotion of cell proliferation and differentiation. 

An ideal scaffold should possess excellent biocompatibility, controllable biodegradability and suitable mechanical characteristics. Several studies have shown that nanofibrous scaffolds can enhance cellular responses like cell adhesion and cell phenotype maintenance. Electrospun PCL nanofibrous scaffolds can be fabricated in the laboratory for the treatment of partial or full thickness skin defects. These nanofibrous wound dressings, due to their porosity and inherent properties might... 

Electrospun SF-based fibers were prepared from aqueous regenerated silkworm silk Bombyx mon)/PEO solutions to be used as scaffolds for tissue engineering (Jin et al. 2004). PEO supplied good mechanical properties to the electrospun fibers. An MeOH posttreatment induced an amorphous to silk p-sheet conformational transition. The electrospun silk membrane was washed with water to remove PEO in order to improve the cell adhesion and proliferation. These silk fibrous membranes were nonimmunogenic, biocompatible, and capable of supporting bone marrow stromal cell (BMSC) attachment. In another work, electrospun wool keratin/silk fibroin (WK/SF) blend nanofibers exhibited higher Cu + adsorption capacity than SF nanofibrous membrane (Ki et al. 2007). 

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