Scaffold polymer film fabrication

One of the key steps en route to a 3-D nanoscopic battery requires fabricating an ultrathin film of a polymer separator/electrolyte over chemically stable, physically rugged, cation-insertion oxide scaffolds, such as supported films of MnOx ambigels. ° In... 

For the third process, conducting polymers and metal oxides can be simultaneously deposited onto carbonaceous scaffolds by using CNTs or graphene as frameworks during chemical process or electrodes in the electrochemical procedure. This is similar to the one-pot synthesis of binary composites. Besides sequential compositing, ternary composites can also be fabricated by a one-step electrochemiccd deposition to reach desirable porous architectures due to its simplicity and reliability. It was proposed to prepare unique PPy/reduced GO/CNT ternary composites, where reduced GO, CNT, and PPy were electro-deposited simultaneously to construct a three-dimensionally highly porous film electrode (Dingetal., 2012). 

Disks of PLGA-laminated polypyrrole thick (2-4 pm) films have been evaluated for their in vivo biocompatibility in rat models with excellent results. Tubular guidance channels fabricated from laminated polypyrrole films have been utilized successfully to bridge a 10-mm. sciatic nerve gap in rat models [52]. These studies have demonstrated the potential of polypyrrole scaffold in particular and electroactive polymers in general in stimulated tissue regeneration. 

Solvent casting and particulate leaching (SC/PL) is a simple and commonly used method for fabricating scaffolds for tissue engineering. With an appropriate thermal treatment, porous constructs of synthetic biodegradable polymers can be prepared with specific porosity, surfaceivolume ratio, pore size and crystallinity for different applications. This method involves mixing water-soluble salt (e.g. sodium chloride, sodium citrate) particles into a polymer solution. The mixture is then cast into the mould of the desired shape. After the solvent is removed by evaporation or lyophilization, the salt particles are leached out to obtain a porous structure with the pore shape limited to the cubic crystal shape of the salt. Removal of soluble particles from the interior of a polymer matrix is difficult and limits the thickness of the films prepared to ca. 2 mm [293]. 

The potential of P3HB films and scaffolds as matrices for cartilage regeneration have been extensively studied in vitro (see Sects. 3.2 and 5.2). Thus for example, nanofibrous polymer mats have been fabricated by electrospinning of P3HB-5%3HV solution and tested as potential scaffolds for chondrocyte attachment [133]. However, animal studies have not yet been reported. 

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