Synthesis and Properties of Multicleavable Amphiphilic Dendritic Comblike and Toothbrushlike Copolymers Comprising Alternating PEG and PCL Grafts

Facile construction of novel functional dendritic copolymers by combination of self-condensing vinyl polymerization, sequence-controlled copolymerization and RAFT process was presented. RAFT copolymerization of a disulfide-linked polymerizable RAFT agent and equimolar feed ratio of styrenic and maleimidic macromonomers afforded multicleavable A_<i>m</i>B_<i>n</i> dendritic comblike copolymers with alternating PEG (A) and PCL (B) grafts, and a subsequent chain extension polymerization of styrene, <i>tert</i>-butyl acrylate, methyl methacrylate, and <i>N</i>-isopropylacrylamide gave A_<i>m</i>B_<i>n</i>C_<i>o</i> dendritic toothbrushlike copolymers. (PEG)_<i>m</i>(PCL)_<i>n</i> copolymers obtained were of adjustable molecular weight, relatively low polydispersity (PDI = 1.10–1.32), variable CTA functionality (<i>f</i>_CTA = 4.3–7.5), and similar segment numbers of PEG and PCL grafts, evident from ¹H NMR and GPC-MALLS analyses. Their branched architecture was confirmed by (a) reduction-triggered degradation, (b) decreased intrinsic viscosities and Mark–Houwink–Sakurada exponent than their “linear” analogue, and (c) lowered glass transition and melting temperatures and broadened melting range as compared with normal A_<i>m</i>B_<i>n</i> comblike copolymer. In vitro drug release results revealed that the drug release kinetics of the disulfide-linked A_<i>m</i>B_<i>n</i> copolymer aggregates was significantly affected by macromolecular architecture, end group and reductive stimulus. These stimuli-responsive and biodegradable dendritic copolymer aggregates had a great potential as controlled delivery vehicles

Additional file 1 of Plastid phylogenomics and fossil evidence provide new insights into the evolutionary complexity of the ‘woody clade’ in Saxifragales

Supplementary Material

Dually pH/Reduction-Responsive Vesicles for Ultrahigh-Contrast Fluorescence Imaging and Thermo-Chemotherapy-Synergized Tumor Ablation

Smart nanocarriers are of particular interest as nanoscale vehicles of imaging and therapeutic agents in the field of theranostics. Herein, we report dually pH/reduction-responsive terpolymeric vesicles with monodispersive size distribution, which are constructed by assembling acetal- and disulfide-functionalized star terpolymer with near-infrared cyanine dye and anticancer drug. The vesicular nanostructure exhibits multiple theranostic features including on-demand drug releases responding to pH/reduction stimuli, enhanced photothermal conversion efficiency of cyanine dye, and efficient drug translocation from lysosomes to cytoplasma, as well as preferable cellular uptakes and biodistribution. These multiple theranostic features result in ultrahigh-contrast fluorescence imaging and thermo-chemotherapy-synergized tumor ablation. The dually stimuli-responsive vesicles represent a versatile theranostic approach for enhanced cancer imaging and therapy