title: Controlled drug release and hydrolysis mechanism of polymer-magnetic nanoparticle composite.
abstract: Uniform and multifunctional poly(lactic acid) (PLA)-nanoparticle composite has enormous potential for applications in biomedical and materials science. A detailed understanding of the surface and interface chemistry of these composites is essential to design such materials with optimized function. Herein, we designed and investigated a simple PLA-magnetic nanoparticle composite system to elucidate the impact of nanoparticles on the degradation of polymer-nanoparticle composites. In order to have an in-depth understanding of the mechanisms of hydrolysis in PLA-nanoparticle composites, degradation processes were monitored by several surface sensitive techniques, including scanning electron microscopy, contact angle goniometry, atomic force microscopy, and sum frequency generation spectroscopy. As a second-order nonlinear optical technique, SFG spectroscopy was introduced to directly probe in situ chemical nature at the PLA-magnetic nanoparticle composite/aqueous interface, which allowed for the delineation of molecular mechanisms of various hydrolysis processes for degradation at the molecular level. The best PLA-NP material, with a concentration of 20% MNP in the composite, was found to enhance the drug release rate greater than 200 times while maintaining excellent controlled drug release characteristics. It was also found that during hydrolysis, various crystalline-like PLA domains on the surfaces of PLA-nanoparticle composites influenced various hydrolysis behaviors of PLA. Results from this study provide new insight into the design of nanomaterials with controlled degradation and drug release properties, and the underlined molecular mechanisms. The methodology developed in this study to characterize the polymer-nanoparticle composites is general and widely applicable.
authors.forename: Fang
authors.initials: F
authors.lastname: Yang
authors.affiliation: ‡Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States.
authors.forename: Xiaoxian
authors.initials: X
authors.lastname: Zhang
authors.forename: Lina
authors.initials: L
authors.lastname: Song
authors.forename: Huating
authors.initials: H
authors.lastname: Cui
authors.affiliation: ‡Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States.
authors.forename: John N
authors.initials: JN
authors.lastname: Myers
authors.forename: Tingting
authors.initials: T
authors.lastname: Bai
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: ‡Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States.
authors.forename: Zhan
authors.initials: Z
authors.lastname: Chen
authors.forename: Ning
authors.initials: N
authors.lastname: Gu
mesh_terms: D003692:Delayed-Action Preparations; D006868:Hydrolysis; D019344:Lactic Acid / Q000737:chemistry*; D058185:Magnetite Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D018625:Microscopy, Atomic Force; D019301:Oleic Acid / Q000737:chemistry; D017239:Paclitaxel / Q000494:pharmacology*; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D013057:Spectrum Analysis; D013997:Time Factors; D014732:Vibration; D014867:Water / Q000737:chemistry
chemical_list: D003692:Delayed-Action Preparations; D058185:Magnetite Nanoparticles; D011091:Polyesters; D011108:Polymers; D014867:Water; D019301:Oleic Acid; D019344:Lactic Acid; C033616:poly(lactide); D017239:Paclitaxel
keywords: composite; controlled drug release; interface hydrolysis; nanoparticles; poly(lactic acid); sum frequency generation