title: Polymeric nanoparticle drug delivery technologies for oral delivery applications.
abstract: BACKGROUND
  Many therapeutics are limited to parenteral administration. Oral administration is a desirable alternative because of the convenience and increased compliance by patients, especially for chronic diseases that require frequent administration. Polymeric nanoparticles (NPs) are one technology being developed to enable clinically feasible oral delivery.
  
  
  METHODS
  This review discusses the challenges associated with oral delivery. Strategies used to overcome gastrointestinal (GI) barriers using polymeric NPs will be considered, including mucoadhesive biomaterials and targeting of NPs to transcytosis pathways associated with M cells and enterocytes. Applications of oral delivery technologies will also be discussed, such as oral chemotherapies, oral insulin, treatment of inflammatory bowel disease, and mucosal vaccinations.
  
  
  CONCLUSIONS
  There have been many approaches used to overcome the transport barriers presented by the GI tract, but most have been limited by low bioavailability. Recent strategies targeting NPs to transcytosis pathways present in the intestines have demonstrated that it is feasible to efficiently transport both therapeutics and NPs across the intestines and into systemic circulation after oral administration. Further understanding of the physiology and pathophysiology of the intestines could lead to additional improvements in oral polymeric NP technologies and enable the translation of these technologies to clinical practice.
authors: Stanford University, School of Medicine , Stanford, CA 94305 , USA epridgen@stanford.edu.
authors: Eric M
authors: EM
authors: Pridgen
authors: Frank
authors: F
authors: Alexis
authors: Omid C
authors: OC
authors: Farokhzad
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001682:Biological Availability; D016503:Drug Delivery Systems; D041981:Gastrointestinal Tract / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000008:administration & dosage; D007413:Intestinal Mucosa / Q000378:metabolism; D053758:Nanoparticles; D011108:Polymers / Q000737:chemistry*
chemical_list: D007328:Insulin; D011108:Polymers
keywords: M cells; chemotherapy; inflammatory bowel disease; insulin; mucoadhesives; mucosal vaccinations; oral delivery; polymeric nanoparticles; transcytosis