Fabrication of combinatorial polymer scaffold libraries.

We have designed a novel combinatorial research platform to help accelerate tissue engineering research. Combinatorial methods combine many samples into a single specimen to enable accelerated experimentation and discovery. The platform for fabricating combinatorial polymer scaffold libraries can be used to rapidly identify scaffold formulations that maximize tissue formation.

Tissue engineering scaffolds based on photocured dimethacrylate polymers for in vitro optical imaging.

Model tissue engineering scaffolds based on photocurable resin mixtures with sodium chloride have been prepared for optical imaging studies of cell attachment. A photoactivated ethoxylated bisphenol A dimethacrylate was mixed with sieved sodium chloride (NaCl) crystals and photocured to form a cross-linked composite. Upon soaking in water, the NaCl dissolved to leave a porous scaffold with desirable optical properties, mechanical integrity, and controlled porosity.

Cellular response to phase-separated blends of tyrosine-derived polycarbonates.

Two-dimensional thin films consisting of homopolymer and discrete compositional blends of tyrosine-derived polycarbonates were prepared and characterized in an effort to elucidate the nature of different cell responses that were measured in vitro. The structurally similar blends were found to phase separate after annealing with domain sizes dependent on the overall composition. The thin polymer films were characterized with the use of atomic force microscopy (AFM), water contact angles, and time-of-flight secondary ion mass spectrometry (TOF-SIMS) and significant changes in roughness were measured following the annealing process.

Effects of electrospinning and solution casting protocols on the secondary structure of a genetically engineered dragline spider silk analogue investigated via Fourier transform Raman spectroscopy.

Micrometer and submicrometer diameter fibers of recombinant dragline spider silk analogues, synthesized via protein engineering strategies, have been electrospun from 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) and compared with cast films via Raman spectroscopy in order to assess changes in protein conformation that may result from the electrospinning process. Although the solvent casting process was shown to result in predominantly beta-sheet conformation similar to that observed in the bulk, the electrospinning process causes a major change in conformation from beta-sheet to alpha-helix. A possible mechanism involving electric field-induced stabilization of alpha-helical segments in HFIP solution during the electrospinning process is discussed.