@article { ISI:000261922400011, title = {Cell proliferation and controlled drug release studies of nanohybrids based on chitosan-g-lactic acid and montmorillonite}, journal = {Acta Biomaterialia}, volume = {5}, number = {1}, year = {2009}, month = {JAN}, pages = {93-100}, publisher = {ELSEVIER SCI LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND}, abstract = {

The present paper reveals the potential uses of novel hybrids of chitosan-g-lactic acid and sodium montmorillonite (MMT) in controlled drug delivery and tissue engineering applications. The drug-loaded novel nanohybrid films and porous scaffolds have been prepared by solvent casting and freeze-drying of the grafted polymer solution, respectively. Sodium Ibuprofen was loaded into nanohybrids of chitosan-g-lactic acid/sodium montmorillonite (CS-g-LA/MMT). Grafting of lactic acid and the drug loading were characterized by Fourier transform infrared spectroscopy. Formation of intercalated nanocomposites was confirmed by X-ray diffraction. Mechanical properties measurements have shown improvement in modulus and strength with expense of elongation by MMT reinforcement. The nanohybrids were found to be stable regardless of pH of the medium. The cell proliferation profile also shows that prepared nanohybrids are biocompatible. MMT reinforcement was found to control the drug (Ibuprofen) release rate in phosphate buffer saline solution (pH 7.4). MMT clay is therefore a viable additive for formulating sustained drug delivery systems based on lactic acid grafted chitosan. (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

}, keywords = {Chitosan, clay, Controlled release, drug delivery systems, Nanocomposites}, issn = {1742-7061}, doi = {10.1016/j.aetbio.2008.08.007}, author = {Depan, Dilip and Kumar, Annamalai Pratheep and Singh, Raj Pal} } @article { ISI:000274069000060, title = {Preparation and characterization of novel hybrid of bio-assisted mineralized Zn-Al layered double hydroxides using chitosan as a template}, journal = {Journal of Applied Polymer Science}, volume = {115}, number = {6}, year = {2010}, month = {MAR}, pages = {3636-3644}, publisher = {JOHN WILEY \& SONS INC}, address = {111 RIVER ST, HOBOKEN, NJ 07030 USA}, abstract = {

The purpose of this study was to prepare and characterize a novel nanohybrid prepared from the template-assisted mineralization of Zn-Al Layered Double Hydroxide (LDH) onto the surface of Chitosan (CSI), with an emphasis on morphology, biocompatibitity, and its use as an efficient drug carrier agent. The as prepared LDH is highly crystalline, with platelet-like morphology and curved tactoids when nucleated onto the surface of CSI. Our results indicate that the -OH and -NH functional moieties on CSI can direct an ordered structure of LDH, due to the electrostatic interaction between biopolymer and inorganic lamellae. We have been successful to intercalate an anti-inflammatory drug, Sodium Ibuprofen (Ibu), into LDH, through conventional coprecipitation method. LDHs are endowed with great potential for delivery vector because their stacked layers lead to safe reservation of biofunctional molecules or genes, and their ion exchangeability and solubility in acidic media (pH \< 4) give rise to the controlled release of drug molecules. According to the cell-growth studies, LDHs are found as cell viable up to the concentration of 500 mu g/mL. This study reveals that LDH not only plays a role of a biocompatible-delivery matrix but also facilitates a significant increase in the delivery efficiency. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115:3636-3644,2010

}, keywords = {bio-assisted mineralization, cell-growth studies, Chitosan, drug delivery systems, layered double hydroxides}, issn = {0021-8995}, doi = {10.1002/app.31463}, author = {Depan, Dilip and Singh, Raj Pal} } @article { ISI:000276061200012, title = {Ultrasound-triggered release of ibuprofen from a chitosan-mesoporous silica composite - a novel approach for controlled drug release}, journal = {Macromolecular Symposia}, volume = {287}, year = {2010}, note = {4th International Symposium on Macro-and Supramolecular Architectures and Materials, Dusseldorf, GERMANY, SEP 07-11, 2008}, month = {JAN}, pages = {80-88}, publisher = {Int Union Pure \& Appl Chem; German Res Fdn}, address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY}, abstract = {

In this work, an attempt was made to synthesize a novel Chitosan-Mesoporous silica (CS-MS) hybrid composite to design a drug delivery system based on ultrasound triggered stimuli-responsive smart release. The in-vitro drug release properties of both the Mesoporous Silica (MS) and Chitosan (CS) hybrids were investigated. Ibuprofen (Ibu) was used as a model drug. The results from powder X-Ray diffraction (XRD) patterns, and BET N(2) adsorption isotherms exhibited that MS can accommodate drug molecules into the lumen of the channels and pores. Drug release, stimulated by temperature and pH of the release media was also investigated. We studied the Ultrasound (US) triggered release of Ibu in a simulated body fluid (pH 7.4). The results exhibited that US can be used as a non-invasive technique for drug release from polymeric materials. The enhancing effect of ultrasound on drug release is due to the Cavitation effect, without causing any significant destruction on the polymer morphology.

}, keywords = {Chitosan, drug delivery systems, ibuprofen, Mesoporous silica, Ultrasound}, issn = {1022-1360}, doi = {10.1002/masy.201050111}, author = {Depan, Dilip and Saikia, Lakshi and Singh, Raj Pal} } @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 {47622, title = {Manipulating hydrophobicity of polyester nanofiber mats with egg albumin to enhance cell interactions}, journal = {Polymer Engineering and Science}, volume = {61}, year = {2021}, month = {OCT}, pages = {2496-2510}, type = {Article}, abstract = {A hybrid of poly-l-lactic acid (PLA) and poly-epsilon-caprolactone (PCL) system was designed using hydrophilic generally regarded as safe (GRAS) protein, egg albumin (EA), and fabricated as nanofiber mats (NM) to facilitate improved cell interactions and functionality. Our studies include, preparation and analysis of physicochemical properties of NM. Surface morphology of NM was smooth with the diameter ranging from 250 to 400 nm. The contact angle of NM decreased from 80 to 45 degrees with the increase in EA concentration. The rate and extent of swelling was increased 3-folds with the addition of EA. Release studies of NM showed maximum amount of MTz was released with the increase in MTz concentration (>85\%). The MTz interaction with EA and structure stability of EA was confirmed from fluorescence and circular dichroism studies. NM showed increase in inhibition of bacterial growth of Staphylococcus aureus and Escherichia coli with the increase in MTz concentration. Cell viability of the NM was >80\% and also, the cell proliferation increased as EA content increased. NM hemolytic activity was less than 5\% suggesting compatibility. Hence, results concluded that EA had regulated hydrophobicity, promoted cell interactions, and proliferation and therefore, NM is considered safe for tissue regeneration.}, keywords = {Biocompatibility, Biomaterials, drug delivery systems, egg albumin, electrospinning, nanofibers, polyesters}, issn = {0032-3888}, doi = {10.1002/pen.25776}, author = {Patel, Pratikshkumar R. and Pandey, Komal and Killi, Naresh and Gundloori, Rathna Venkata Naga} } @article {48316, title = {Controlled synthesis of thermosensitive tunable porous film of (pNIPAM)-b-(PCL) copolymer for sustain drug delivery}, journal = {Journal of Applied Polymer Science}, volume = {140}, year = {2023}, month = {MAY}, pages = {e53854}, type = {Article}, abstract = {

There have been reports on different types of porous polymer films for various applications. The designing of such porous films with uniform properties is a challenging task. In this work, tunable porous thin films of poly(N-isopropylacrylamide) (pNIPAM) and polycaprolactone (PCL), that is, (pNIPAM)-b-(PCL) has been fabricated and its sustained drug delivery applications have been reported. First, the (pNIPAM)-b-(PCL) has been synthesized through the addition polymerization of pNIPAM and PCL. Then the synthesized (pNIPAM)-b(PCL) has been used to design porous thin film with varying temperatures without using any external template, below and above the lower critical solution temperatures (LCST) of pNIPAM. Pore size in (pNIPAM)-b-(PCL) films has been tuned by varying the temperature from similar to 10 to 40 degrees C. Then the developed thermosensitive porous film has been taken and seeded with the K562 (chronic myeloid leukemia blood cancer) and HepG2 (hepatocarcinoma) cells and the skin cancer cells (B16-F10) killing efficiency of anticancer drug (e.g., doxorubicin hydrochloride, DOX) loaded (pNIPAM)-b-(PCL) film has been studied. It is found that the DOX-loaded (pNIPAM)-b-(PCL) can efficiently kill the skin cancer cells. The porous polymer thin film reported in this work can be a versatile platform for the loading of drugs and it can be used for the various therapeutic applications.

}, keywords = {Biomaterials, Biomedical Applications, drug delivery systems, films, nanostructured polymers}, issn = {0021-8995}, doi = {10.1002/app.53854}, author = {Amgoth, Chander and Patra, Sukanya and Wasnik, Kirti and Maity, Pradip and Paik, Pradip} } @article {49794, title = {Redox- and pH-responsive block copolymer nanocarriers with dual drug conjugation through dynamic covalent and hydrogen bonds}, journal = {Journal of Applied Polymer Science}, volume = {143}, year = {2026}, month = {MAR}, pages = {e70205}, type = {Article}, abstract = {

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.

}, keywords = {biodegradable, copolymers, DOX-conjugate, drug delivery systems, methotrexate, micelles, pH-responsive, redox-responsive}, issn = {0021-8995}, doi = {10.1002/app.70205}, author = {Avhad, Shankarrao V. and Surapaneni, Sai Geetika and Purohit, Poorvi M. and Ambade, Ashootosh V.} }