@article {45888, title = {Bioactive thermoresponsive polyblend nanofiber formulations for wound healing}, journal = {Materials Science \& Engineering C-Materials for Biological Applications}, volume = {48}, year = {2015}, month = {MAR }, pages = {126-137}, type = {Article}, abstract = {

The rationale of this work is to develop new bioactive thermoresponsive polyblend nanofiber formulations for wound healing (topical). Various polymer compositions of thermoresponsive, poly(N-isopropylacrylamide), egg albumen and poly(epsilon-caprolactone) blend solutions with and without a drug [gatifloxacin hydrochloride, Gati] were prepared. Non-woven nanofibers of various compositions were fabricated using an electrospinning technique. The morphology of the nanofibers was analyzed by an environmental scanning electron microscope. The morphology was influenced by the concentration of polymer, drug, and polymer blend composition. Fourier transform infrared spectroscopy analysis showed the shift in bands due to hydrogen ion interactions between polymers and drug. Thermogram of PNIPAM/PCL/EA with Gati recorded a shift in lower critical solution temperature (LCST) and glass transition temperature (T-g) of PNIPAM. Similarly T-g and melting temperature (T-m) of PCL were shifted. X-ray diffraction patterns recorded a decrease in the crystalline state of PCL nanofibers and transformed crystalline drug to an amorphous state. In vitro release study of nanofibers with Gati showed initial rapid release up to 10 h, followed by slow and controlled release for 696 h (29 days). Nanofiber mats with Gati exhibited antibacterial properties to Staphylococcus aureus, supported suitable controlled drug release with in vitro cell viability and in vivo wound healing. (C) 2014 Elsevier B.V. All rights reserved.

}, keywords = {Antibacterial, Cell viability, drug release, nanofibers, thermoresponsive, wound Healing}, issn = {0928-4931}, doi = {10.1016/j.msec.2014.11.037}, author = {Pawar, Mahesh D. and Rathna, G. V. N. and Agrawal, Shubhang and Kuchekar, Bhanudas S.} } @article { ISI:000360829900002, title = {Blends of shellac as nanofiber formulations for wound healing}, journal = {Journal of Bioactive and Compatible Polymers}, volume = {30}, number = {5}, year = {2015}, month = {SEP}, pages = {472-489}, publisher = {SAGE PUBLICATIONS LTD}, address = {1 OLIVERS YARD, 55 CITY ROAD, LONDON EC1Y 1SP, ENGLAND}, abstract = {

Shellac is being used in food, pharmaceutical, and agricultural industries. It is seldom used for biomedical applications due to its poor mechanical property and instability. We designed thermoresponsive shellac-based bioactive nanofiber mats that mimic extracellular matrix to extend their utility in wound healing. Various blend compositions of shellac, gelatin, and poly(N-isopropylacrylamide) enriched with a bioactive agent, nadifloxacin, were prepared and nanofiber mats were fabricated. The morphology of the nanofiber formation was influenced by the concentration of polymer, drug, and polymer blend composition. Polymer-drug interactions and thermal and crystalline properties of nanofiber mats were analyzed. The shellac/gelatin/poly(N-isopropylacrylamide) blend of composition 3\%/7\%/3\% (w/v) was chosen to evaluate in vitro drug release. Release studies recorded slow, constant, and sustained release for 140h. The release kinetics and mechanism confirmed zero-order release with resultant r(2) values greater than 0.99, and the Korsmeyer-Peppas release exponent (n) was slightly higher than 0.8, which indicated that drug diffusion was anomalous or non-Fickian type and drug release followed diffusion involving chain stretching. Indirect cytotoxicity studies recorded insignificant toxicity against normal human fibroblast cells. In vivo studies demonstrated that drug-loaded nanofiber mats were more suitable for faster tissue regeneration as compared to nanofiber mats without drug and commercial nadifloxacin cream.

}, keywords = {drug release and mechanism, nanofibers, Shellac, thermoresponsive, tissue regeneration}, issn = {0883-9115}, doi = {10.1177/0883911515585180}, author = {Vannuruswamy, Garikapati and Rathna, Gundloori Venkata Naga and Gadgil, Bhagyashri Shashikant Thorat and Gadad, Anand Panchakshari} } @article {45509, title = {New approach for the synthesis of miktoarm star polymers through a combination of thiol-epoxy {\textquoteleft}{\textquoteleft}click{\textquoteright}{\textquoteright} chemistry and ATRP/Ring-opening polymerization techniques}, journal = {Journal of Polymer Science Part A-Polymer Chemistry}, volume = {57}, year = {2019}, month = {JAN }, pages = {146-156}, type = {Article}, abstract = {

A new approach was developed for synthesis of certain A(3)B(3)-type of double hydrophilic or amphiphilic miktoarm star polymers using a combination of {\textquoteleft}{\textquoteleft}grafting onto{\textquoteright}{\textquoteright} and {\textquoteleft}{\textquoteleft}grafting from{\textquoteright}{\textquoteright} methods. To achieve the synthesis of desired miktoarm star polymers, acetyl protected poly(ethylene glycol) (PEG) thiols (M-n = 550 and 2000 g mol(-1)) were utilized to generate A(3)-type of homoarm star polymers through an in situ protective group removal and a subsequent thiol-epoxy {\textquoteleft}{\textquoteleft}click{\textquoteright}{\textquoteright} reaction with a tris-epoxide core viz. 1,1,1-tris(4-hydroxyphenyl)ethane triglycidyl ether. The secondary hydroxyl groups generated adjacent to the core upon the thiol-epoxy reaction were esterified with alpha-bromoisobutyryl bromide to install atom transfer radical polymerization (ATRP) initiating sites. ATRP of N-isopropylacrylamide (NIPAM) using the three-arm star PEG polymer fitted with ATRP initiating sites adjacent to the core afforded A(3)B(3)-type of double hydrophilic (PEG)(3)[poly(N-isopropylacrylamide)] (PNIPAM)(3) miktoarm star polymers. Furthermore, the generated hydroxyl groups were directly used as initiator for ring-opening polymerization of epsilon-caprolactone to prepare A(3)B(3)-type of amphiphilic (PEG)(3)[poly(epsilon-caprolactone)](3) miktoarm star polymers. The double hydrophilic (PEG)(3)(PNIPAM)(3) miktoarm star polymers showed lower critical solution temperature around 34 degrees C. The preliminary transmission electron microscopy analysis indicated formation of self-assembly of (PEG)(3)(PNIPAM)(3) miktoarm star polymer in aqueous solution. (c) 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 146-156

}, keywords = {Atom transfer radical polymerization (ATRP), miktoarm star polymers, ring-opening polymerization (ROP), thermoresponsive, thiol-epoxy}, issn = {0887-624X}, doi = {10.1002/pola.29278}, author = {Gadwal, Ikhlas and Wadgaonkar, Prakash P. and Ichake, Amol B. and Mane, Shivshankar R.} }