Target drug delivery system as a new scarring modulation after glaucoma filtration surgery

BACKGROUND: Excessive wound healing following glaucoma filtration surgery is the main determinant of surgical failure, resulting from the activation of human Tenon's capsule fibroblasts (HTFs). To mitigate the excessive wound healing, the topicall use of antiproliferative agents, such as mitomycin C (MMC) and 5-fluorouracil (5-FU), has increased the surgery success rate, but the traditional administration of these agents can result in a variety of toxicities with nonspecific damage. However, modulation of the wound healing process to prevent excessive fibroblast proliferation and scar formation can play a major role in improving the outcome of surgery. Therefore, the search for alternative modes of drug delivery and new agents is needed to minimize the ocular complications and improve the success of surgery. We have shown that there is a postoperative overexpression of the LDL receptor (LDLr) in the activated HTFs may provide a novel target for drug delivery systems. PRESENTATION OF THE HYPOTHESIS: We hypothesize that antifibrotic agents (MMC) encapsulated in LDLr targeting drug delivery system (LDL-MMC-chitosan nanoparticles) may be proposed in anti-scarring therapy to increase the safety and effectiveness and to reduce toxicity. TESTING THE HYPOTHESIS: A chitosan-based polymeric predrug of MMC was synthesized and its cytotoxicity was proved to be low. In addition, we propose hyaluronic acid film as a container to release LDL-MMC-chitosan nanoparticles gradually at subconjunctival filtering site after glaucoma filtration surgery to eliminate the LDL-MMC-chitosan nanoparticles. IMPLICATIONS OF THE HYPOTHESIS AND DISCUSSION: This strategy can be applicable to anti-scarring therapy during excessive conjunctival wound healing. This hypothesis integrates advantages of the targeting drug delivery and antifibrotic agents, such as high efficiency, convenience, and lower the toxicity.