Uterocalin-Loaded Polyanhydride Microspheres for Wound Healing Applications

Biodegradable polyanhydride microspheres exhibit excellent characteristics for therapeutic drug delivery. In particular, amphiphilic polyanhydrides based on 1,8-bis(p-carboxylphenoxy)-3,6-dioxane (CPTEG) and 1,6-bis(p-carboxyphenoxy)hexane (CPH) provide a gentle environment for protein stabilization and delivery. This study investigated the application of CPTEG and CPTEG:CPH copolymer microspheres as carriers for uterocalin, a 24kDa mouse protein which has been shown to expedite wound healing. The objectives were to encapsulate and stabilize uterocalin within the microspheres, and test the biological activity of released uterocalin on wound healing in vitro. The microspheres were fabricated using cryogenic atomization, which maximized protein loading. Characterization of the released protein by SDS-PAGE suggested the uterocalin was released intact from the microspheres without alteration to its primary structure. The biological activity of the released uterocalin was quantified using a cell migration assay with human colorectal carcinoma (HCT 116) cells. The effectiveness of CPTEG and CPTEG:CPH microspheres as protein carriers as well as their potential for therapeutic delivery of uterocalin for wound healing will be discussed.