title: Polycation-b-polyzwitterion copolymer grafted luminescent carbon dots as a multifunctional platform for serum-resistant gene delivery and bioimaging.
abstract: Nanomaterials that integrate functions of imaging and gene delivery have been of great interest due to their potential use in simultaneous diagnosis and therapy. Herein, polycation-b-polysulfobetaine block copolymer, poly[2-(dimethylamino) ethyl methacrylate]-b-poly[N-(3-(methacryloylamino) propyl)-N,N-dimethyl-N-(3-sulfopropyl) ammonium hydroxide] (PDMAEMA-b-PMPDSAH) grafted luminescent carbon dots (CDs) were prepared via surface-initiated atom transfer radical polymerization (ATRP) and investigated as a multifunctional gene delivery system (denoted as CD-PDMA-PMPD) in which the CD cores acted as good multicolor cell imaging probes, the cationic PDMAEMA acted as a DNA condensing agent, and the outer shell of zwitterionic PMPDSAH block protected the vector against nonspecific interactions with serum components. As revealed by the fluorescent spectrum study, the photoluminescent attributes, especially the tunable emission property, were well inherited from the parent CDs. The CD-PDMA-PMPD could condense plasmid DNA into nanospheres with sizes of approximate 50 nm at a proper complex ratio, posing little cytotoxicity at higher ratios. It was shown that the hybrid vector exhibited significantly suppressed BSA protein adsorption and superior hemocompatibility compared to those of the widely used PEI25k. In the in vitro transfection assay, an increased serum concentration from 10 to 50% caused a dramatic drop in PEI25k transfection performance, whereas the transfection efficiency of CD-PDMA-PMPD was well maintained; CD-PDMA80-PMPD40 showed 13 and 28 times higher transfection efficiencies than PEI25k at 30 and 50% serum concentration, respectively. Intriguingly, the carbon dots in the transfected cells displayed excitation-dependent fluorescent emissions, portending that this polycation-polyzwitterion modified CD will be a promising theranostic vector with excellent stealth performance.
authors.affiliation: School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Tianjin University , Tianjin 300072, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Cheng
authors.forename: Yongmao
authors.initials: Y
authors.lastname: Li
authors.forename: Xinyun
authors.initials: X
authors.lastname: Zhai
authors.forename: Bing
authors.initials: B
authors.lastname: Xu
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Cao
authors.forename: Wenguang
authors.initials: W
authors.lastname: Liu
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry* / Q000633:toxicity; D019556:COS Cells; D002244:Carbon / Q000737:chemistry*; D002417:Cattle; D002522:Chlorocebus aethiops; D004912:Erythrocytes / Q000166:cytology / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects; D008856:Microscopy, Fluorescence; D049329:Nanostructures / Q000737:chemistry / Q000633:toxicity; D010957:Plasmids / Q000737:chemistry / Q000378:metabolism; D011073:Polyamines / Q000737:chemistry*; D000071228:Polyelectrolytes; D011108:Polymers / Q000737:chemistry*; D011485:Protein Binding; D011817:Rabbits; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism; D014162:Transfection
chemical_list: D001672:Biocompatible Materials; D002244:Carbon; D011073:Polyamines; D000071228:Polyelectrolytes; D011108:Polymers; D012710:Serum Albumin, Bovine
keywords: bioimaging; carbon dots; gene delivery; polysulfobetaine; serum resistance