@article { ISI:000282471100001, title = {Enhancement of thermal stability and phase relaxation behavior of chitosan dissolved in aqueous l-lactic acid: using {\textquoteleft}silver nanoparticles{\textquoteright} as nano filler}, journal = {Macromolecular Research}, volume = {18}, number = {8}, year = {2010}, month = {AUG}, pages = {713-720}, publisher = {SPRINGER}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

Chitosan films with various compositions of silver nanoparticles were prepared by solution casting with an aqueous solution of chitosan and l-lactic acid. The chitosan/Ag nanocomposites were characterized by wide angle Xray diffraction (WAXD) and UV-vis spectroscopy. An analysis of the surface topography and size of the Ag nanoparticles (\<= 100 nm) were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. Thermogravimetric analysis (TGA/DTA) confirmed the increase in thermal stability with increasing Ag nanoparticle content in the nanocomposites. Dynamic thermal analysis (DMA) was used to examine the phase relaxation behavior of chitosan and its nanocomposites. The conductivity of chitosan/Ag nanocomposites was considered with respect to the frequency. Contact angle measurements were used to characterize the surface twistability, surface cleanliness, and hydrophilic/hydrophobic nature of the surface.

}, keywords = {Chitosan, conductivity, contact angle, relaxation, silver nanoparticles}, issn = {1598-5032}, doi = {10.1007/s13233-010-0801-9}, author = {Rana, V. K. and Pandey, Asutosh K. and Singh, Raj Pal and Kumar, B. and Mishra, Satyendra and Ha, Chang-Sik} } @article { ISI:000282128700005, title = {Tensile properties, cell adhesion, and drug release behavior of chitosan-silver-gelatin nanohybrid films and scaffolds}, journal = {Macromolecular Research}, volume = {18}, number = {9}, year = {2010}, month = {SEP}, pages = {845-852}, publisher = {SPRINGER}, address = {233 SPRING ST, NEW YORK, NY 10013 USA}, abstract = {

Drug-loaded nanohybrid films and porous scaffolds were prepared using chitosan, Ag nanoparticles and gelatin using a solution casting and freeze-drying method, respectively. Gelatin was used to incorporate the cell onto the surface of the scaffolds and the nanohybrid films. 1-[2-hydroxyethyl]-2-methyl-5-nitroimidazole) (Metronidazole (MTZ) was used as a model drug. The small percentage of Ag nanoparticles in the nanohybrid films and scaffolds produced significantly higher cell proliferation and levels of drug release. The tensile properties showed improvement in strength by Ag nanoparticles reinforcement at the expense of elongation.

}, keywords = {carcinogenic metronidazole, cell proliferation, chitosan-Ag-gelatin nanohybrids, drug release, nano-hybrids, scaffolds}, issn = {1598-5032}, doi = {10.1007/s13233-010-0905-2}, author = {Rana, V. K. and Kushwaha, Omkar S. and Singh, RajPal and Mishra, Satyendra and Ha, Chang-Sik} } @article { ISI:000299066700002, title = {Hierarchical mesoporous bio-polymer/silica composites co-templated by trimethyl chitosan and a surfactant for controlled drug delivery}, journal = {Medchemcomm}, volume = {2}, number = {12}, year = {2011}, month = {DEC}, pages = {1162-1166}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

In this communication, we report the facile synthesis of hierarchical mesoporous bio-polymer/silica composite materials with bimodal mesopores using a dual-template of the cationic N,N,N-trimethyl chitosan (TMCs) and the anionic sodium dodecyl sulfate (SDS) via one-step synthetic strategy. Tetraethoxysilane (TEOS) was used as a silica source. The nitrogen adsorption/desorption measurements and transmission electron microscopy analysis showed the hierarchical structure of the mesoporous bio-polymer/silica composites with bimodal mesopores having an average pore size of 5-7 nm with the visible voids between the silica nanoparticles, which allow the mesoporous bio-polymer/silica composites to encapsulate a large number of guest drug molecules, Ibuprofen (IBU) or 5-fluorouracil (5-FU), due to their high surface area and pore volume. In addition, the mesoporous chitosan-silica composites also had a long term biocompatibility for the target release of the drug molecules to the CEM cells, MCF cells, etc. as well as a pH sensitive controlled release behavior of the drug molecules.

}, issn = {2040-2503}, doi = {10.1039/c0md00222d}, author = {Rana, Vijay Kumar and Park, Sung Soo and Parambadath, Surendran and Kim, Mi Ju and Kim, Sun-Hee and Mishra, Satyendra and Singh, Raj Pal and Ha, Chang-Sik} } @article { ISI:000287163600004, title = {Synthesis and drug-delivery behavior of chitosan-functionalized graphene oxide hybrid nanosheets}, journal = {Macromolecular Materials and Engineering}, volume = {296}, number = {2}, year = {2011}, month = {FEB}, pages = {131-140}, publisher = {WILEY-V C H VERLAG GMBH}, address = {BOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANY}, abstract = {

Chitosan-functionalized graphene oxides (FGOCs) were successfully synthesized. FGOCs were found to significantly improve the solubility of the GO in aqueous acidic media. The presence of organic groups was confirmed by means of XPS and TGA. Restoration of the sp(2) carbon network and exfoliation of graphene sheets were confirmed by Raman spectroscopy, UV-visible spectroscopy and WAXD. The SEM and AFM investigations of the resultant FGOCs showed that most of the graphene sheets were individual and few were layered. Controlled release behavior of Ibuprofen and 5-fluorouracil was then investigated. We found that FGOCs are a promising new material for biological and medical applications.

}, keywords = {Biocompatibility, Chitosan, drug delivery systems, functionalization of polymers, solution properties}, issn = {1438-7492}, doi = {10.1002/mame.201000307}, author = {Rana, Vijay Kumar and Choi, Myeon-Cheon and Kong, Jin-Yeon and Kim, Gwang Yeon and Kim, Mi Ju and Kim, Sun-Hee and Mishra, Satyendra and Singh, Raj Pal and Ha, Chang-Sik} } @article { ISI:000308896400057, title = {Heterocyclic tri-urea isocyanurate bridged groups modified periodic mesoporous organosilica synthesized for Fe(III) adsorption}, journal = {Journal of Solid State Chemistry}, volume = {194}, year = {2012}, month = {OCT}, pages = {392-399}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, abstract = {

To achieve a high level of heavy metal adsorption, 1,1{\textquoteright},1 {\textquoteleft}{\textquoteright}-(1,3,5-triazine-2,4,6-triyl)tris(3-(3-(triethoxysilyl) propyl)urea) (TTPU) was synthesized as a novel melamine precursor and incorporated on the silica surface of periodic mesoporous organosilica (PMO). The melamine modified PMOs (MPMOs) were synthesized under acidic conditions using TTPU, tetraethylorthosilicate (TEOS) and Pluronic P123 as a template and the modified PMOs were characterized using the relevant instrumental techniques. The characteristic materials were used as adsorbents for the adsorption of Fe(III) ions. Fe(III) adsorption studies revealed MPMO-7.5 to be a good absorbent with higher adsorption efficiency than other MPMOs. (C) 2012 Elsevier Inc. All rights reserved.

}, keywords = {Adsorption efficiency, Fe(III) adsorption, Melamine, Periodic mesoporous organosilica (PMO)}, issn = {0022-4596}, doi = {10.1016/j.jssc.2012.05.019}, author = {Rana, Vijay Kumar and Selvaraj, M. and Parambadath, Surendran and Chu, Sang-Wook and Park, Sung Soo and Mishra, Satyendra and Singh, Raj Pal and Ha, Chang-Sik} } @article { ISI:000331624700039, title = {Chitosan and chitosan-co-poly(epsilon-caprolactone) grafted multiwalled carbon nanotube transducers for vapor sensing}, journal = {Journal of Nanoscience and Nanotechnology}, volume = {14}, number = {3}, year = {2014}, month = {MAR}, pages = {2425-2435}, publisher = {AMER SCIENTIFIC PUBLISHERS}, type = {Article}, address = {26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USA}, abstract = {

Vapor sensitive transducer films consisting of chitosan grafted (CNT-CS) and chitosan-co-polycaprolactone grafted (CNT-CS-PCL) multiwalled carbon nanotubes were prepared using a spray layer-by-layer technique. The synthesized materials (CNT-CS and CNT-CS-PCL) were characterized by Fourier transform infrared spectroscopy, C-13 CP/MAS solid state nuclear magnetic resonance spectroscopy and thermogravimetric analysis. Both CNT-CS and CNT-CS-PCL transducers were analyzed for the response of volatile organic compounds and toluene vapors. The ranking of the relative resistance (A(r)) for both chitosan based transducers were as follows: toluene \< chloroform \< ethanol \< methanol. The CNT transducer (CNT-CS) was correlated selectively with an exponential law to the inverse of Flory-Huggins interaction parameters, chi(12). Dosing the films on the interdigitated electrodes with methanol, ethanol, chloroform and toluene vapors increased the film resistance of CNT-CS but decreased the resistance of CNT-CS-PCL compared to that of the reported transducers.

}, keywords = {Biocompatibility, Chitosan, MWCNTs, Poly(epsilon-caprolactone), Vapour Sensing}, issn = {1533-4880}, doi = {10.1166/jnn.2014.8498}, author = {Rana, Vijay Kumar and Akhtar, Shamim and Chatterjee, Sudipta and Mishra, Satyendra and Singh, Raj Pal and Ha, Chang-Sik} }