title: Adsorption/desorption and bioavailability of methamphetamine in simulated gastrointestinal fluids under the presence of multiwalled carbon nanotubes.
abstract: Adsorption/desorption and desorption hysteresis of methamphetamine (MMA) on carbon nanotubes (CNTs) as well as bioavailability of MMA were studied in simulated gastrointestinal fluids and background fluids. Adsorption of MMA in near-neutral (weak alkaline) intestinal fluid was enhanced, while adsorption of MMA on CNTs in acid gastric fluid was suppressed. Desorption of MMA is divided into fast and slow stages, and fast desorption conducting in the gastric fluid lasted shortly and slow desorption occurred in intestinal fluid; pepsin can enhance the release of MMA in gastrointestinal system. While, the acidic condition in gastric fluid is the main factor which causes the release of MMA. The amount of MMA released from CNTs in different fluids follows the order gastric > background (pH = 2.0) > intestinal (fed) > intestinal (fasted) > background (pH = 7.5). These findings in the simulated gastrointestinal system suggest that the release of MMA from CNTs could be promoted by biomacromolecules (such as pepsin and bile salts in digestive tract); thus, the bioavailability of MMA is enhanced.
authors: Tianjin Key Laboratory of Water Quality Science and Technology, School of Municipal and Environmental Engineering, Tianjin Chenjian University, Tianjin, 300384, People's Republic of China.
authors: Jing
authors: J
authors: Zhang
authors: Zhenhu
authors: Z
authors: Xiong
authors: Lei
authors: L
authors: Wang
authors: Kai
authors: K
authors: Zhang
mesh_terms: D000327:Adsorption; D001647:Bile Acids and Salts / Q000378:metabolism*; D001682:Biological Availability; D019149:Bioreactors; D005766:Gastrointestinal Contents / Q000737:chemistry; D008694:Methamphetamine / Q000378:metabolism*; D037742:Nanotubes, Carbon / Q000737:chemistry*; D010434:Pepsin A / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D001647:Bile Acids and Salts; D037742:Nanotubes, Carbon; D014874:Water Pollutants, Chemical; D008694:Methamphetamine; D010434:Pepsin A