title: Chitosan-based responsive hybrid nanogels for integration of optical pH-sensing, tumor cell imaging and controlled drug delivery.
abstract: We report a new class of chitosan-based hybrid nanogels by in-situ immobilization of CdSe quantum dots (QDs) in the chitosan-poly(methacrylic acid) (chitosan-PMAA) networks. The covalently crosslinked hybrid nanogels with chitosan chains semi-interpenetrating in the crosslinked PMAA networks exhibit excellent colloidal and structural stability as well as reversible physical property change in response to a pH variation cross the physiological condition. In contrast, the hybrid nanogels formed by non-covalent physical association exhibit a significant change in the structure and composition upon exposure to physiological pH. This distinction in the structural stability of hybrid nanogels produces very different outcomes for their biomedical applications. The covalently crosslinked hybrid nanogels are low-cytotoxic and could illuminate the B16F10 cells, sense the environmental pH change, and regulate the release of anticancer drug in the typical abnormal pH range of 5-7.4 found in pathological zone, thus successfully combine multiple functionality into a single nano-object. However, the physically associated hybrid nanogels exhibit a non-reversible pH-sensitive PL property and a significant cytotoxicity after 24 h treatment. It is critical to construct a highly stable biopolymer-QD hybrid nanogel, via a rational design for safe bionanomaterials, to simultaneously combine the biosensing, bioimaging, and effective therapy functions.
authors.affiliation: Department of Chemistry, College of Staten Island, and The Graduate Center, The City University of New York, Staten Island, NY 10314, USA.
authors.forename: Weitai
authors.initials: W
authors.lastname: Wu
authors.forename: Jing
authors.initials: J
authors.lastname: Shen
authors.forename: Probal
authors.initials: P
authors.lastname: Banerjee
authors.forename: Shuiqin
authors.initials: S
authors.lastname: Zhou
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000379:methods; D019187:Cadmium Compounds / Q000737:chemistry; D045744:Cell Line, Tumor; D002470:Cell Survival; D048271:Chitosan / Q000737:chemistry*; D003692:Delayed-Action Preparations / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008545:Melanoma / Q000175:diagnosis*; D051379:Mice; D008853:Microscopy / Q000379:methods; D011109:Polymethacrylic Acids / Q000737:chemistry; D045663:Quantum Dots; D018036:Selenium Compounds / Q000737:chemistry
chemical_list: D019187:Cadmium Compounds; D003692:Delayed-Action Preparations; D020100:Hydrogels; D011109:Polymethacrylic Acids; D018036:Selenium Compounds; C030613:polymethacrylic acid; D048271:Chitosan; C058667:cadmium selenide