Background Postoperative pain remains a significant problem despite optimal treatment with current drugs. Nonsteroidal antiinflammatory drugs reduce inflammation and provide analgesia, but are associated with adverse side effects. Methods We tested low doses (0.5 – 5 mg/kg) of parenteral ketoprofen against pain related behaviors after plantar incision in rats. To further evaluate the potential sites of action of ketoprofen in our model, a novel, sustained-release microparticle formulation of ketoprofen was placed into the wound, and tested for its effects on pain behaviors. Intrathecal ketoprofen (150 mcg) was also studied. Plasma samples were assayed for drug concentrations. Results We found that low doses of parenterally administered ketoprofen produced a modality specific effect on pain behaviors; guarding after incision was decreased, whereas no inhibition of exaggerated responses to heat or mechanical stimuli was evident. Very low doses, 0.5 mg/kg, could produce inhibition of guarding. The locally applied sustained release ketoprofen-eluting microparticles and intrathecally administered ketoprofen also produced a modality-specific effect on pain behaviors after incision, inhibiting only guarding. Plasma levels of ketoprofen after parenteral or local administration were in the range of therapeutic blood levels in postoperative patients. Conclusions This study demonstrates that ketoprofen is an effective analgesic for nonevoked guarding in rats after plantar incision. There was no effect on mechanical or heat responses, which highlights the importance of multiple modality testing of pain behaviors for drug evaluation. We found efficacy at doses used clinically in postoperative patients.

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Introduction: There is considerable interest in the use of three-dimensional porous scaffolds for tissue regeneration. The presence of an interconnected framework of pores with large surface area facilitates the formation of extracellular matrix and permits cellular ingrowth into implanted structures. For scaffolds to be useful for tissue regeneration, they must maintain good dimensional stability during the lifetime of the implant. While the initial scaffold architecture is often well characterized, a systematic study of the influence of incubation on the scaffold architecture is critical to ensure that the scaffolds retain their interconnected network of pores during their useful lifetime. Herein, we report on the evaluation of the architecture of polyarylate scaffolds and their stability under in vitro conditions using scanning electron microscopy (SEM).The polymers used in this study were selected from a library of degradable polyarylates. This library is the first reported combinatorial library of biodegradable condensation polymers.