01955nas a2200217   4500008004100000022001400041245007700055210006900132260000800201300001400209490000700223520124600230100001701476700001701493700002101510700002601531700003501557700002101592700001701613856010701630       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  uhttps://library.ncl.res.in/content/silk-fibroin-sophorolipid-gelation-deciphering-underlying-mechanism01670nas a2200205   4500008004100000022001400041245009800055210006900153260000800222300001600230490000700246520095900253100002201212700001501234700002101249700002101270700001701291700002601308856013001334       2019                        eng d  a0743-746300aSilk fibroin-sodium dodecyl sulfate gelation: molecular, structural, and rheological insights0 aSilk fibroinsodium dodecyl sulfate gelation molecular structural  cNOV  a14870-148780 v353 a<p>A gelling agent is necessary to accelerate sol to gel transition in an aqueous solution of silk fibroin (SF), which otherwise takes several days to complete. In this paper, we investigate the mechanism of gelation of Bornbyx mori SF by a model anionic surfactant, sodium dodecyl sulfate (SOS). Even though interactions between SDS and proteins have been extensively investigated, most of these studies have focused on globular proteins, which undergo denaturation. The interaction with a fibrous protein such as SF is different and results in an altered secondary structure leading to gelation. In this work, the concentration-dependent gelation process of the SF-SDS system is examined using rheology, SANS, FTIR, and NMR. We observed preferential binding of SDS to specific regions on the SF chain, which aids structural changes favoring beta-sheet formation. We propose a mechanism for the accelerated sol-gel transition in the SF-SDS system.</p>
1 aHirlekar, Swarali1 aRay, Debes1 aAswal, Vinod, K.1 aPrabhune, Asmita1 aNisal, Anuya1 aRavindranathan, Sapna  uhttps://library.ncl.res.in/content/silk-fibroin-sodium-dodecyl-sulfate-gelation-molecular-structural-and-rheological-insights