title: Size-dependent nanoparticulate drug delivery in inflammatory bowel diseases.
abstract: BACKGROUND
  Inflammatory bowel disease (IBD) is a chronic autoimmune disease, whose main forms are Crohn's disease and ulcerative colitis. The main treatment of IBD includes oral administration of anti-inflammatory or immunosuppressive agents enclosed in traditional dosage forms, intended to release the active ingredient in the large intestine. However, most of them have been designed based on the physiology of healthy colon, which differs distinctly from conditions met in IBD patients risking adverse effects and patient intolerance. The use of nanoparticles as a drug carrier for treatment of IBD is a promising approach that is capable of solving this problem. Previous studies have shown a size-dependent behavior, where reducing the particle size, increases the targeting efficacy and the residence time compared to healthy controls.
  
  
  METHODS
  This review covers the utilization of nanoparticles as drug delivery carriers for treating IBD. They can reach the inflamed colonic sites either by endothelial or epithelial delivery employing passive and active targeting strategies. The effect of particle size is analyzed in detail while elucidating other essential parameters such as the particle surface properties.
  
  
  CONCLUSIONS
  One of the most important advantages of nanoparticles is their passive targeting to the inflamed colonic tissues due to their size. Recent findings underline that this size-dependent bioadhesion behavior can be further enhanced by selecting smart surface properties to help in penetrating the mucus and reach the inflamed sites.
authors.affiliation: a Department of Pharmaceutics , Institute of Pharmacy, University of Bonn , Bonn , Germany.|b Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy , Ain Shams University , Cairo , Egypt.
authors.forename: John
authors.initials: J
authors.lastname: Youshia
authors.affiliation: a Department of Pharmaceutics , Institute of Pharmacy, University of Bonn , Bonn , Germany.|c Laboratory of Pharmaceutical Engineering, EA 4267 , University of Franche-Comté , Besançon , France.
authors.forename: Alf
authors.initials: A
authors.lastname: Lamprecht
mesh_terms: D000284:Administration, Oral; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage*; D003106:Colon / Q000378:metabolism; D016503:Drug Delivery Systems / Q000379:methods*; D006801:Humans; D007166:Immunosuppressive Agents / Q000008:administration & dosage*; D015212:Inflammatory Bowel Diseases / Q000188:drug therapy*; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size
chemical_list: D000893:Anti-Inflammatory Agents; D007166:Immunosuppressive Agents
keywords: Active targeting; inflammatory bowel disease; nanoparticles; particle size; passive targeting; surface charge