Investigation of the mechanical properties and biocompatibility of planar and electrospun alkene-styrene copolymers against P(VDF-TrFE) and porcine skin: Potential use as second skin substrates.

Elastomers have been used in a variety of biomedical fields, including tissue engineering, soft robotics, prostheses, and cosmetics. Elastomers used for skin grafting scaffolds tend to be biodegradable, but other applications require perdurable elastomers. Advances in perdurable elastomers would allow for the development of a range of substrates useful in the creation of joint prostheses, chronic neural electrodes, implantables, and wearables. Still, for these, tailored mechanical properties and biocompatibility are required. In this work, several perdurable alkene-styrene elastomers and novel polymer blends are investigated for their stress-strain curves; with quantification of Young's moduli, fatigue behavior and standard biocompatibility. In particular, this study attempts to study polymers with mechanical properties similar to the complex characteristics of skin, through comparison with porcine skin samples. Poly (vinylidene fluoride-trifluoroethylene), P(VDF-TrFE), a flexible polymer previously used as a wearable sensor and second skin component, was here used for comparison studies. Interestingly, this study points out that elastomer mechanical properties can be modulated to better replicate the elastic modulus of skin, in particular for KratonTM D1152, a Styrene-Butadiene-Styrene block copolymer. Namely, this is the case when such an elastomer is prepared as an electrospun matrix or as a flat dense film under low temperatures. Moreover, a specific method was optimized to obtain electrospun fibers of this alkene-styrene copolymer.

Infectious alphavirus production from a simple plasmid transfection+.

We have developed a new method for producing infectious double subgenomic alphaviruses from plasmids transfected into mammalian cells. A double subgenomic Sindbis virus (TE3'2J) was transcribed from a cytomegalovirus PolII promoter, which results in the production of infectious virus. Transfection of as little as 125 ng of plasmid is able to produce 1 × 10(8) plaque forming units/ml (PFU/ml) of infectious virus 48 hours post-transfection. This system represents a more efficient method for producing recombinant Sindbis viruses.