Laura A Smith Callahan

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Stem cell therapies, which aim to restore neurological function after central nervous system injury, have shown increased efficacy when a tissue engineering matrix is implanted with cells compared to implantation of the cells alone. However, much work still needs to be done to characterize materials that can be used to facilitate and direct the(More)
Amino acid-based poly(ester urea)s (PEU) are high modulus, resorbable polymers with many potential uses, including the surgical repair of bone defects. In vitro and in vivo studies have previously shown that phenylalanine-based PEUs have nontoxic hydrolytic byproducts and tunable degradation times. Phenylalanine PEUs (poly(1-PHE-6)) have been further(More)
New systematic approaches are necessary to determine and optimize the chemical and mechanical scaffold properties for hyaline cartilage generation using the limited cell numbers obtained from primary human sources. Peptide functionalized hydrogels possessing continuous variations in physico-chemical properties are an efficient three-dimensional platform for(More)
Stem cells have shown lineage-specific differentiation when cultured on substrates possessing signaling groups derived from the native tissue. A distinct determinant in this process is the concentration of the signaling motif. While several groups have been working actively to determine the specific factors, concentrations, and mechanisms governing the(More)
The synthesis of a 4-dibenzocyclooctynol (DIBO) functionalized polyethylene glycol (PEG) and fabrication of hydrogels via strain-promoted, metal-free, azide-alkyne cycloaddition is reported. The resulting hydrogel materials provide a versatile alternative in which to encapsulate cells that are sensitive to photochemical or chemical crosslinking mechanisms.
Materials currently used for the treatment of bone defects include ceramics, polymeric scaffolds and composites, which are often impregnated with recombinant growth factors and other bioactive substances. While these materials have seen instances of success, each has inherent shortcomings including prohibitive expense, poor protein stability, poorly defined(More)
Mechanotransduction in neural cells involves multiple signaling pathways that are not fully understood. Differences in lineage and maturation state are suggested causes for conflicting reports on neural cell mechanosensitivity. To optimize matrices for use in stem cell therapy treatments transplanting human induced pluripotent stem cell derived neural stem(More)
Many studies have utilized Irgacure 2959 photopolymerized poly(ethylene glycol) (PEG) hydrogels for tissue engineering application development. Due to the limited penetration of ultraviolet light through tissue, Irgacure 2959 polymerized hydrogels are not suitable for use in tissues where material injection is desirable, such as the spinal cord. To address(More)
N-cadherin cell-cell signaling plays a key role in the structure and function of the nervous system. However, few studies have incorporated bioactive signaling from n-cadherin into tissue engineering matrices. The present study uses a continuous gradient approach in polyethylene glycol dimethacrylate hydrogels to identify concentration dependent effects of(More)
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