Poly tissue engineering systems

As mentioned earlier, poly(NIPAAm-co-AAc) where AAc content is small (2-5 mol%) forms loose hydrogels above the LOST. This makes the system an attractive candidate for tissue engineering application as an extracellular matrix (ECM). Above a critical concentration, aqueous polymer solutions of W-isopropylacrylamide copolymers with small amounts of acrylic acid, synthesized in benzene by free radical polymerization, exhibited four distinct phases as the temperature increased a clear solution, an opaque solution, a gel, and a shrunken gel. The transition between the opaque solution phase and the gel phase was in the range of 30-34°C and was... 

Polyanhydrides have been developed into various systems with mainly bone tissue engineering applications in mind. These polymers have mechanical strength much lower than that of bone but have been combined with other polymers, such as poly(imide)s, to resolve this problem. Polyanhydrides have been developed into photo-cross-linkable systems, based on dimethacrylated anhydrides, and also injectable systems, but little interest into these polymers with regard to tissue engineering has been taken in the recent past [82]. 

So far, polyanhydrides have only been approved by the FDA as a drug dehvery system commercially produced by Guilford. Chemotherapeutic agent BCNU (carmustine) loaded in poly(CPP-SA) 20 80 wafer (Gliadel ) was used for treating brain tumors [161,194,195], More applications in controlled release include eye disorder, local anesthetics, and anticoagulants [194], Further biocompatibility analyses need to be conducted for the use of polyanhydrides in other tissue engineering applications. 

Electrospun conducting libers are also used in the production of biocompative systems for tissue engineering and biosensors. poly(lactic-co-glycolic acid) (PLXiA) electrospun nanolibers coated with PPy were also produced for neural tissue applications. 

A mixture of dimethyl sulfoxide/tetrahydrofuran (THE) was used to obtain homogeneous blended nanofibers of an HCl-doped poly(aniline-co-3-aminobenzoic acid) (3ABA-PANI) copolymer and poly(lactic acid) (PLA) for tissue engineering. Since the solvent system dimethyl sulfoxide (DMS0)/THF (50 50) is quite difficult to be removed from the nonwoven mats, the authors used a heated collector to facilitate solvent removal. This procedure can be considered essential in cases where nonwoven fiber mats will be used in cell growth. Besides, composite electroactive fibers achieve lower con-... 

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