Kristine Schmalenberg

Synthesis and Cytotoxicity of Salicylate-Based Poly(anhydride esters)

This paper describes the synthesis and cytotoxicity of poly(anhydride esters) that are composed of several salicylate derivatives, including halogenated salicylates, aminosalicylates, salicylsalicylic acid, and thiolsalicylic acid. The incorporation of these nonsteroidal antiinflammatory drugs (NSAIDs) into a biodegradable polymer backbone yields drug-based polymers that have potential for a variety of applications. The poly(anhydride esters) were synthesized by melt condensation polymerization. The halogenated salicylate derivatives yielded the highest molecular polymers as well as the highest glass transition temperatures. All polymers displayed in vitro degradation lag times from 1 to 3 days, depending on the water solubility of the salicylate derivative. Cell viability and proliferation were determined with L929 fibroblast cells in serum-containing medium to assess the polymer cytotoxicities, which varied as a function of the saliyclate chemistry. Cell morphology was normal for most of the polymers evaluated.

Directed attachment of Schwann cells on protein micropatterned degradable polymeric substrates

After injury to the peripheral nervous system, axons from regenerating nerve cells must reach their innervation target to restore function. Polymeric substrates are currently being evaluated as nerve guides to enhance recovery after peripheral nerve injury. Degradable organic polymer substrates are highly suitable materials as matrices for tissue engineering because they can be specifically designed to serve as scaffolds then be absorbed by the body leaving only native tissue. Protein patterns on polymeric nerve guides may help maximize functional repair after injury because chemical cues can direct cellular components to their intended targets. Using microcontact printing techniques, protein stripes were patterned onto several different degradable polymeric substrates including poly(caprolactone), poly(caprolactam) and poly(3-hydroxybutyrate). The fluorescently tagged protein micro-patterns were visualized by confocal scanning laser fluorescence microscopy. The micropatterned polymer substrates were evaluated for their ability to direct attachment and alignment of Schwann cells (a cellular component of the peripheral nervous system).