title: The use of charge-coupled polymeric microparticles and micromagnets for modulating the bioavailability of orally delivered macromolecules.
abstract: Protein drugs have low bioavailability after oral administration, which is due in part to fast transit of the drugs or drug delivery vehicles through the gastrointestinal tract. Increasing the time that the drugs spend in the intestine after dosing would allow for greater absorption and increased bioavailability. We developed a formulation strategy that can be used to prolong intestinal retention of drug delivery vehicles without substantial alterations to current polymeric encapsulation strategies. A model drug, insulin, was encapsulated in negatively charged poly(lactic-co-glycolic acid) (PLGA) microparticles, and the microparticles were subsequently mixed with positively charged micromagnets, whose size will prevent them from being absorbed. Stable complexes formed through electrostatic interaction. The complexes were effectively immobilized in vitro in a model of the mouse small intestine by application of an external magnetic field. Mice that were gavaged with radio-labeled complexes and fitted with a magnetic belt retained 32.5% of the (125)I-insulin in the small intestine compared with 5.4% for the control group 6h after administration (p=0.005). Furthermore, mice similarly gavaged with complexes encapsulating insulin (120 Units/kg) exhibited long-term glucose reduction in the groups with magnetic belts. The corresponding bioavailability of insulin was 5.11% compared with 0.87% for the control group (p=0.007).
authors: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
authors: Benjamin A
authors: BA
authors: Teply
authors: Rong
authors: R
authors: Tong
authors: Seok Y
authors: SY
authors: Jeong
authors: Gaurav
authors: G
authors: Luther
authors: Ines
authors: I
authors: Sherifi
authors: Christopher H
authors: CH
authors: Yim
authors: Ali
authors: A
authors: Khademhosseini
authors: Omid C
authors: OC
authors: Farokhzad
authors: Robert S
authors: RS
authors: Langer
authors: Jianjun
authors: J
authors: Cheng
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001672:Biocompatible Materials; D001682:Biological Availability; D016503:Drug Delivery Systems; D007328:Insulin / Q000008:administration & dosage / Q000493:pharmacokinetics; D019344:Lactic Acid; D008280:Magnetics; D008422:Materials Testing; D051379:Mice; D010316:Particle Size; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011108:Polymers; D011506:Proteins / Q000008:administration & dosage* / Q000493:pharmacokinetics*
chemical_list: D001672:Biocompatible Materials; D007328:Insulin; D011108:Polymers; D011506:Proteins; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid