02241nas a2200241 4500008004100000022001400041245018700055210006900242260000800311300001100319490000800330520134800338653001801686653001301704653001801717653001801735653002001753653003101773100002201804700002601826700002201852856012501874 2024 eng d a0014-305700aPhoto and pH dual stimuli-responsive block copolymer micelles with defined incorporation of o-nitrobenzyl units in poly(ε-caprolactone) ε-caprolactone) block for controlled release0 aPhoto and pH dual stimuliresponsive block copolymer micelles wit cNOV a1135010 v2203 a

A series of dual stimuli-responsive block copolymers with varying content of photocleavable o-nitrobenzyl (ONB) ester group pendent in the hydrophobic poly(epsilon-caprolactone) block and pH-cleavable acetal linkage at the junction with hydrophilic poly(ethylene glycol) block is synthesized. The hydrophobic block is a random copolymer synthesized by ring-opening copolymerization of epsilon-caprolactone and ONB-substituted epsilon-caprolactone containing varying compositions of the two monomers. Kinetics of polymerization shows that ONBfunctionalized monomer has lower reactivity than that of the unsubstituted monomer. The series of block copolymers shows self-assembly into well-defined spherical micelles of average size of 150-200 nm in aqueous solution. Photocleavage of ONB groups is studied by NMR and UV-vis spectroscopy, and its extent is determined. The two stimuli viz. . UV light and pH are used individually as well as simultaneously to study the controlled release of the encapsulated drug Camptothecin and the synergistic effect of the two stimuli is demonstrated. The effect of varying content of ONB groups is observed on drug release profile. MTT assay showed non-cytotoxic nature of the polymer. Cell uptake and photoinduced release of doxorubicin (DOX) from the micelles in MDAMB-231 cells is demonstrated.

10adrug delivery10amicelles10aO-nitrobenzyl10apH-responsive10aPhotoresponsive10aPoly(epsilon-caprolactone)1 aAvhad, Shankarrao1 aChoudhari, Shakeb, N.1 aAmbade, Ashootosh uhttps://library.ncl.res.in/content/photo-and-ph-dual-stimuli-responsive-block-copolymer-micelles-defined-incorporation-o01982nas a2200241 4500008004100000022001400041245013900055210006900194260000900263300001200272490000700284520113000291653001101421653001901432653001301451653001801464653002901482100002401511700002901535700002101564700002601585856012901611 2024 eng d a1060-132500aVisible light and pH-responsive star copolymer and doxorubicin-polymer conjugate micelles for combination drug delivery and bioimaging0 aVisible light and pHresponsive star copolymer and doxorubicinpol cFEB  a105-1160 v613 a

Amphiphilic 3-arm star copolymer containing visible light-cleavable BODIPY group and pH-responsive imine bonds at the junction of hydrophilic poly(ethylene glycol) (PEG) and two poly(epsilon-caprolactone) (PCL) arms was synthesized by the combination of ring-opening polymerization (ROP) and click chemistry. The formation and stimuli-responsive disruption of micelles were analyzed using dynamic light scattering and transmission electron microscopy. Dual stimuli-responsive release of anticancer drugs Doxorubicin (Dox) and Camptothecin (CPT) from the micelles was studied. Micellar assemblies containing Dox conjugated to PEG-BODIPY through imine bonds were prepared and controlled release of Dox in response to visible light and pH was shown. CPT and Dox-loaded star copolymer micelles as well as CPT loaded Dox-conjugated micelles were used in cellular uptake studies on MDA-MB 231 cells, and the synergistic effect of the two stimuli on the release of the two drugs was demonstrated inside the cells. Micellar assemblies also showed excellent bioimaging properties in the cellular uptake studies. [GRAPHICS]

10aBODIPY10adrug conjugate10amicelles10apH-responsive10avisible light-responsive1 aBasutkar, Nitin, B.1 aSurapaneni, Sai, Geetika1 aAlam, Md., Shafi1 aAmbade, Ashootosh, V. uhttps://library.ncl.res.in/content/visible-light-and-ph-responsive-star-copolymer-and-doxorubicin-polymer-conjugate-micelles02255nas a2200277 4500008004100000022001400041245012900055210006900184260000800253300001100261490000800272520131600280653001801596653001501614653001801629653002601647653001701673653001301690653001801703653002101721100002601742700002901768700002401797700002601821856013001847 2026 eng d a0021-899500aRedox- and pH-responsive block copolymer nanocarriers with dual drug conjugation through dynamic covalent and hydrogen bonds0 aRedox and pHresponsive block copolymer nanocarriers with dual dr cMAR ae702050 v1433 a

Loading of multiple drugs in a nanocarrier with high entrapment efficiency is important for combination therapy in cancer treatment. Here, a block copolymer comprising hydrophobic poly(epsilon-caprolactone) block with a defined number of pendent propargyl groups, polyethylene glycol monomethyl ether as a hydrophilic block, and a redox-responsive disulfide group at the block junction is synthesized using click chemistry and ring-opening polymerization (ROP). Benzaldehyde and thymine groups are introduced in the side chains for selective attachment of anti-cancer drugs, doxorubicin (DOX) and methotrexate (MTX), via the formation of pH-responsive imine linkage and hydrogen bonds, respectively. The drug-conjugated block copolymers are assembled into spherical micelles of < 200 nm, and the preferential release of DOX and MTX in response to acidic pH and redox conditions is shown. At pH 5, DOX release was 59.5%, and MTX release was 40% compared to 13% and 12% at pH 7.4, whereas at pH 5 with 10 mM GSH, a DOX release of 81.5% was observed after 48 h. Cellular uptake of drug-conjugated micelles and their apoptosis compared to free DOX in the MDA-MB-231 breast cancer cells is demonstrated. Caveolae-mediated endocytosis was found to be the major pathway used by drug-loaded nanocarriers.

10abiodegradable10acopolymers10aDOX-conjugate10adrug delivery systems10amethotrexate10amicelles10apH-responsive10aredox-responsive1 aAvhad, Shankarrao, V.1 aSurapaneni, Sai, Geetika1 aPurohit, Poorvi, M.1 aAmbade, Ashootosh, V. uhttps://library.ncl.res.in/content/redox-and-ph-responsive-block-copolymer-nanocarriers-dual-drug-conjugation-through-dynamic