title: pH-Responsive nanoparticles for drug delivery.
abstract: First-generation nanoparticles (NPs) have been clinically translated as pharmaceutical drug delivery carriers for their ability to improve on drug tolerability, circulation half-life, and efficacy. Toward the development of the next-generation NPs, researchers have designed novel multifunctional platforms for sustained release, molecular targeting, and environmental responsiveness. This review focuses on environmentally responsive mechanisms used in NP designs, and highlights the use of pH-responsive NPs in drug delivery. Different organs, tissues, and subcellular compartments, as well as their pathophysiological states, can be characterized by their pH levels and gradients. When exposed to these pH stimuli, pH-responsive NPs respond with physicochemical changes to their material structure and surface characteristics. These include swelling, dissociating or surface charge switching, in a manner that favors drug release at the target site over surrounding tissues. The novel developments described here may revise the classical outlook that NPs are passive delivery vehicles, in favor of responsive, sensing vehicles that use environmental cues to achieve maximal drug potency.
authors.affiliation: Laboratory of Nanomedicine and Biomaterials, Department of Anesthesiology, Brigham and Women's Hospital, Boston, Massachusetts 02115, United States.
authors.forename: Weiwei
authors.initials: W
authors.lastname: Gao
authors.forename: Juliana M
authors.initials: JM
authors.lastname: Chan
authors.forename: Omid C
authors.initials: OC
authors.lastname: Farokhzad
mesh_terms: D004337:Drug Carriers / Q000737:chemistry*; D016503:Drug Delivery Systems; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles / Q000737:chemistry*
chemical_list: D004337:Drug Carriers