TY - JOUR T1 - Epithelial Heparin Delivery via Microspheres Mitigates Experimental Colitis in Mice JF - Journal of Pharmacology and Experimental Therapeutics JO - J Pharmacol Exp Ther SP - 726 LP - 733 DO - 10.1124/jpet.106.117226 VL - 321 IS - 2 AU - Yann Pellequer AU - Yvette Meissner AU - Nathalie Ubrich AU - Alf Lamprecht Y1 - 2007/05/01 UR - http://jpet.aspetjournals.org/content/321/2/726.abstract N2 - Low-molecular-weight heparins (LMWH) have been shown to be efficient in the treatment of inflammatory bowel disease (IBD). Parenteral heparin therapy, however, may cause hemorrhagic adverse effects. To reduce this risk, epithelial LMWH delivery in combination with a system ensuring selective drug release to the inflamed tissue was tested here. Enoxaparin loaded microspheres (MS) were administered orally to male BALB mice suffering from a pre-existing experimental colitis, whereas control groups received subcutaneous or rectal LMWH solution. Colon weight/length index and alkaline phosphatase and myeloperoxidase activities were assessed to determine the inflammation. Tissue penetration experiments elucidated the processes involved in the proposed new therapeutic approach. Oral LMWH-MS proved to be equally efficient in mitigating experimental colitis as rectally administered LMWH solution when quantified by myeloperoxidase activity (MS, 10.2 ± 1.5 U/mg tissue; rectal, 9.2 ± 1.6 U/mg) and to be superior to subcutaneous LMWH (s.c., 21.6 ± 5.6 U/mg; untreated colitis control, 30.0 ± 3.8 U/mg). Pharmacokinetic studies found a notably low systemic availability of oral LMWH delivered from MS (<5%) indicating a low potential for adverse effects. The tissue permeability was selectively enhanced in the inflamed regions where a 9-fold higher LMWH penetration was found compared with healthy tissue. Epithelial LMWH delivery has been found a promising anti-inflammatory therapeutic approach. The use of LMWH-MS in this context offers a promising tool for IBD therapy by enhancing specifically drug availability at inflamed tissue sites while reducing the risk for systemic adverse effects to a negligibly low level. The American Society for Pharmacology and Experimental Therapeutics ER -