title: Polyacrylic acid modified upconversion nanoparticles for simultaneous pH-triggered drug delivery and release imaging.
abstract: A poly(acrylicacid)-modified NaYF4:Yb, Er upconversion nanoparticles (PAA-UCNPs) with dual functions of drug delivery and release imaging have been successfully developed. The PAA polymer coated on the surface of UCNPs serve as a pH-sensitive nanovalve for loading drug molecules via electrostatic interaction. The drug-loading efficiency of the PAA-UCNPs was investigated by using doxorubicin hydrochloride (DOX) as a model anticancer drug to evaluate their potential as a delivery system. Results showed loading and releasing of DOX from PAA-UCNPs were controlled by varying pH, with high encapsulation rate at weak alkaline conditions and an increased drug dissociation rate in acidic environment, which is favorable for construct a pH-responsive controlled drug delivery system. The in vitro cytotoxicity test using HeLa cell line indicated that the DOX loaded PAA-UCNPs (DOX@PAA-UCNPs) were distinctly cytotoxic to HeLa cells, while the PAA-UCNPs were highly biocompatible and suitable to use as drug carriers. Furthermore, the upconversion fluorescence resonance energy transfer (UFRET) imaging through the two-photon laser scanning microscopy (TLSM) revealed the time course of intracellular delivery of DOX from DOX@PAA-UCNPs. Thus, PAA-UCNPs are effective for constructing pH-responsive controlled drug delivery systems for multi-functional cancer therapy and imaging.
authors.affiliation: State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Biology, College of Chemistry and Chemical Engineering, Hunan University, Key Laboratory for Bio-Nanotechnology and Molecule Engineering of Hunan Province, Changsha 410082, China.
authors.forename: Xuekun
authors.initials: X
authors.lastname: Jia
authors.forename: Jinjin
authors.initials: J
authors.lastname: Yin
authors.forename: Dinggeng
authors.initials: D
authors.lastname: He
authors.forename: Xiaoxiao
authors.initials: X
authors.lastname: He
authors.forename: Kemin
authors.initials: K
authors.lastname: Wang
authors.forename: Mian
authors.initials: M
authors.lastname: Chen
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Li
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics; D002470:Cell Survival / Q000187:drug effects; D020099:Coated Materials, Biocompatible / Q000737:chemistry; D003692:Delayed-Action Preparations / Q000737:chemistry*; D004317:Doxorubicin / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D004337:Drug Carriers / Q000737:chemistry*; D016503:Drug Delivery Systems; D031541:Fluorescence Resonance Energy Transfer; D006367:HeLa Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles / Q000737:chemistry*
chemical_list: D000180:Acrylic Resins; D000970:Antineoplastic Agents; D020099:Coated Materials, Biocompatible; D003692:Delayed-Action Preparations; D004337:Drug Carriers; C006903:carbopol 940; D004317:Doxorubicin