@article { ISI:000243821700012, title = {Structural evolutions of hydrothermally prepared mesostructured MCM-48 silica using differently manufactured amorphous silica powders}, journal = {Journal of Non-Crystalline Solids}, volume = {353}, number = {2}, year = {2007}, month = {FEB}, pages = {194-199}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The hydrothermal synthesis of Si-MCM-48 mesoporous molecular sieves was carried out using a ternary SiO2:CTAOH:H2O System wherein differently manufactured amorphous silica powders such as fumed silica (FMDS), spray dried precipitated silica (SDPS) and flash dried precipitated silica (FDPS) were used as silica source materials. The changes in structural/textural properties were evaluated using powder XRD, N-2 adsorption-desorption and scanning electron microscopy techniques. Studies on the progressive development of MCM-48 mesophases revealed that, the reactivity of the silica source follow the trend: FMDS \> SDPS \> FDPS. MCM-48 synthesized using low cost FDPS has exhibited thicker pore walls but poorer orderness, while MCM-48 prepared from relatively expensive FMDS has thinner pore walls and more ordered structure. Moreover, the extent of contraction caused by calcinations, agglomerate size and structural stability were found to depend on the reactivity of the silica source used. (c) 2006 Elsevier B.V. All rights reserved.

}, keywords = {long-range order, micelles, scanning electron microscopy, silica, silicates, sol-gels (xerogels), X-ray diffraction}, issn = {0022-3093}, doi = {10.1016/j.jnoncrysol.2006.10.005}, author = {Taralkar, U. S. and Jha, Ratnesh Kumar and Joshi, P. N.} } @article { ISI:000340414900005, title = {Effect of the branching pattern of hydrophobic dendrons on the core structure of linear-dendritic copolymer micelles}, journal = {Macromolecular Chemistry and Physics}, volume = {215}, number = {15}, year = {2014}, month = {AUG}, pages = {1456-1465}, publisher = {WILEY-V C H VERLAG GMBH}, type = {Article}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

Hydrophobic dendrons based on different branching patterns, viz. 3,5-di- and 3,4,5-trisubstituted phenyl rings, consist of the same backbone but exhibit different sizes, shapes, and hydrophobic densities. These dendrons are attached to poly(ethylene glycol) and the core properties of the copolymer micelles are investigated in tetrahydrofuran (THF)/water mixtures by neutron scattering. Two polymers with intermediate hydrophobicity are studied further with variations in the solvent composition and the temperature. The aggregation numbers for 3,4,5-based dendron copolymers are lower, with more THF molecules of solvation compared with the 3,5-based dendron copolymer, the difference being greater at higher generations due to different molecular shapes. The micellar core size increases in small steps with dendron size so that dye encapsulation is tuned.

}, keywords = {diblock copolymers, linear-dendritic copolymers, micelles, neutron scattering, structure-property relations}, issn = {1022-1352}, doi = {10.1002/macp.201400150}, author = {Kalva, Nagendra and Aswal, Vinod K. and Ambade, Ashootosh V.} } @article {46976, title = {Self-assembly of bispentadecylphenol substituted perylenediimide with PS-b-P4VP for structure-property insight into the core of core-shell micelles}, journal = {ACS Applied Polymer Materials}, volume = {2}, year = {2020}, month = {FEB}, pages = {805-816}, type = {Article}, abstract = {

We report the use of a ditopic molecular probe bispentadecylphenol substituted perylenediimide (PBI-PDP) to examine the molecular level self-assembly of polystyrene-b-poly(4-vinylpyridine) (PS-b-P4VP) in tetrahydrofuran (THF). A series of complexes were prepared between PS-b-P4VP copolymers with varying lengths of the 4-vinylpyridine chain and PBI-PDP. Light scattering and NMR spectroscopic studies reveal that the self-assembled structures of the solid complexes are not fully disrupted when the complexes are dissolved in THF. NMR experimental parameters measured for the small probe molecule provide detailed insights into the structure of the assemblies in solution as well as the interaction between the small molecule and the block copolymer. Such insights can have important implications in manipulating the nanostructure of block copolymer micelles to suit various application requirements. The dynamics and distribution of the PBI-PDP molecules within the assemblies in solution show a dependence on the length of the P4VP block. Transmission electron microscopy was employed to study the evolution of morphologies in films prepared from the self-assembled structures in THF solutions.

}, keywords = {core corona interface, ditopic molecular probe, environment, micelles, perylenediimide, PS-b-P4VP, Self-assembly}, issn = {2637-6105}, doi = {10.1021/acsapm.9b01099}, author = {Roy, Moumita and Rajamohanan, Pattuparambil R. and Ravindranathan, Sapna and Asha, S. K.} } @article {46675, title = {Stimuli-responsive biodegradable polyurethane nano-constructs as a potential triggered drug delivery vehicle for cancer therapy}, journal = {International Journal of Pharmaceutics}, volume = {588}, year = {2020}, month = {OCT }, pages = {119781}, type = {Review}, abstract = {

Polyurethanes (PUs) constitute an essential class of stimuli-responsive and biodegradable material, which has significantly contributed to the advancement of polymers utilization in the biomedical field. The bio-erodible PUs construct an active corridor for facilitating drug into tumor cells, which has significantly impacted the progression of nano-micellar delivery systems. The self-assembled colloidal PUs pose distinctive features such as enhancing the solubility of hydrophobic chemotherapeutics, rapid cellular uptake, triggered erosion and drug release, bio-stimulus sensitivity, improvement in the targeting and proficiency of bioactive. Cationic PUs can easily be condensed with genetic material to form polyplexes and have shown excellent transfection efficiency for potential gene therapy against various cancers. Their modifiable chemistry offers a tool to impart the desired multifunctionality such as biocompatibility, sensitivity to pH, redox, temperature, enzyme, etc. and ligand conjugation for active targeting. These diverse exceptional properties make them excellent nano-carrier for a variety of bioactive, including chemotherapeutic drugs, DNA, RNA, and diagnostic moieties to the target tissue or cells. The PUs based nano-devices have certainly uncovered the path to achieve ideal systems for controlled personalized therapy. The literature discussed in this review shed light on the research innovations carried out in the last ten years for the development of multifunctional PUs for triggered delivery of bioactive to treat various cancers.

}, keywords = {Cancer nanomedicine, GSH, micelles, Polyurathanes, redox, Stimuli-responsive}, issn = {0378-5173}, doi = {10.1016/j.ijpharm.2020.119781}, author = {Gajbhiye, Kavita R. and Chaudhari, Bhushan P. and Pokharkar, Varsha B. and Pawar, Atmaram and Gajbhiye, Virendra} } @article {49311, title = {Photo and pH dual stimuli-responsive block copolymer micelles with defined incorporation of o-nitrobenzyl units in poly(ε-caprolactone) ε-caprolactone) block for controlled release}, journal = {European Polymer Journal}, volume = {220}, year = {2024}, month = {NOV}, pages = {113501}, type = {Article}, abstract = {

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.

}, keywords = {drug delivery, micelles, O-nitrobenzyl, pH-responsive, Photoresponsive, Poly(epsilon-caprolactone)}, issn = {0014-3057}, doi = {10.1016/j.eurpolymj.2024.113501}, author = {Avhad, V. Shankarrao and Choudhari, Shakeb N. and Ambade, V. Ashootosh} } @article {49026, title = {Visible light and pH-responsive star copolymer and doxorubicin-polymer conjugate micelles for combination drug delivery and bioimaging}, journal = {Journal of macromolecular science part A- pure and applied chemistry}, volume = {61}, year = {2024}, month = {FEB }, pages = {105-116}, type = {Article}, abstract = {

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]

}, keywords = {BODIPY, drug conjugate, micelles, pH-responsive, visible light-responsive}, issn = {1060-1325}, doi = {10.1080/10601325.2024.2302857}, author = {Basutkar, Nitin B. and Surapaneni, Sai Geetika and Alam, Md. Shafi and Ambade, Ashootosh V.} }