01896nas a2200193   4500008004100000022001400041245010500055210006900160260011000229300001600339490000600355520112300361100001701484700001901501700001901520700001701539700002101556856012501577       2015                        eng d  a2046-206900aSophorolipid assisted tunable and rapid gelation of silk fibroin to form porous biomedical scaffolds0 aSophorolipid assisted tunable and rapid gelation of silk fibroin  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAR  a33955-339620 v53 a<p>Three dimensional polymer hydrogels, based on both natural and synthetic polymers, are increasingly being used as scaffolds and drug delivery vehicles for biomedical applications. Fibrous protein, silk fibroin (SF), obtained from the Bombyx mori silkworm is a promising candidate in this area. However, SF has a long gelation time of about a few weeks that can only be reduced by non-physiological treatments (e. g. high temperature, ultrasonication and low pH) or by addition of a chemical and non-biodegradable polymer and/or surfactant. We report here accelerated gelation of SF under physiological conditions using a biosurfactant, sophorolipid (SL) as a gelling agent. SL and SF are completely miscible and form a very clear solution upon mixing. Hence it is interesting to see that this clear solution gels in a time span of just a few hours. The hydrogels so formed have pore architecture, porosities and mechanical stability ideally suited for tissue culture applications. Here we also demonstrate that mouse fibroblast cells not only adhere to but also extensively proliferate on these SF-SL scaffolds.</p>1 aDubey, Parul1 aNawale, Laxman1 aSarkar, Dhiman1 aNisal, Anuya1 aPrabhune, Asmita  uhttp://library.ncl.res.in/content/sophorolipid-assisted-tunable-and-rapid-gelation-silk-fibroin-form-porous-biomedical-001954nas a2200217   4500008004100000022001400041245007700055210006900132260000800201300001400209490000700223520124600230100001701476700001701493700002101510700002601531700003501557700002101592700001701613856010601630       2016                        eng d  a1525-779700aSilk fibroin-sophorolipid gelation: deciphering the underlying mechanism0 aSilk fibroinsophorolipid gelation deciphering the underlying mec  cOCT  a3318-33270 v173 a<p>Silk fibroin (SF) protein, produced by silkworm Bombyx mori, is a promising biomaterial, while sophorolipid (SL) is an amphiphilic functional biosurfactant synthesized by nonpathogenic yeast Candida bombicola. SL is a mixture of two forms, acidic (ASL) and lactonic (LSL), which when added to SF results in accelerated gelation of silk fibroin. LSL is known to have multiple biological functionalities and hence hydrogels of these green molecules have promising applications in the biomedical sector. In this work, SANS, NMR, and rheology are employed to examine the assembling properties of individual and mixed SLs and their interactions with SF to understand the mechanism that leads to rapid gelation. SANS and NMR studies show that ASL assembles to form charged micelles, while LSL forms micellar assemblies and aggregates of a mass fractal nature. ASL and LSL together form larger mixed micelles, all of which interact differently with SF. It is shown that preferential binding of LSL to SF causes rapid unfolding of the SF chain leading to the formation of intermolecular beta sheets, which trigger fast gelation. Based on the observations, a mechanism for gelation of SF in the presence of different sophorolipids is proposed.</p>1 aDubey, Parul1 aKumar, Sugam1 aAswal, Vinod, K.1 aRavindranathan, Sapna1 aRajamohanan, Pattuparambil, R.1 aPrabhune, Asmita1 aNisal, Anuya  uhttp://library.ncl.res.in/content/silk-fibroin-sophorolipid-gelation-deciphering-underlying-mechanism