02363nas a2200193 4500008004100000022001400041245009200055210006900147260007100216300001400287490000700301520165100308100001601959700001801975700001701993700001702010700002202027856012002049 2012 eng d a1525-779700aSynthesis of silk fibroin-glycopolypeptide conjugates and their recognition with lectin0 aSynthesis of silk fibroinglycopolypeptide conjugates and their r a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcNOV a3695-37020 v133 a

Silk fibroin (SF), the natural fibrous protein created by the Bombyx mori silk worm, is being increasingly excellent mechanical strength, high oxygen/water permeability, excellent mechanical strength; high oxygen/water:permeability, and biocompatibility: :It is also well known that surface. modification of SF, With Organic ligands such as the extracellular protein :binding. Arg-Gly-Asp, (RGD) peptides:,: help adhesion and,proliferation. of cells better-a key; requirement for it to function as extracellular. matrices; In this, Work, We have conjugated synthetic glycopolypeptides (GPs) that were synthesized by controlled ring opening polymerization of alpha-manno-lys N-carboxyanhydrides (NCAs) onto SF by using Cu catalyzed click reaction to synthesize 1 a new hybrid :Material (SF GP), Which We believe will have :both the mechanical properties of native SF and the molecular recognition property of the carbohydrates in the GP. By controlling the :amount of GP grafted onto SF, we have made three SF GP conjugates that differ in their ability to assemble into films. SF GP conjugates having a very high content of GP formed completely water soluble brush like polymer that displayed very high affinity toward the lectin concanavalin-A (Con-A) Films cast from SF-GP conjugates using lower amounts of grafted GP were more stable in water, and the stability can be modulated by varying the amount of G grafted. The water insoluble film SF-GP(25) was also found to bind to fluorescently labeled Con A, as was seen by confocal microscopy Such SF-GP hybrid films may be useful as mimics of extracellular matrices for tissue engineering:

1 aDas, Soumen1 aPati, Debasis1 aTiwari, Neha1 aNisal, Anuya1 aGupta, Sayam, Sen uhttp://library.ncl.res.in/content/synthesis-silk-fibroin-glycopolypeptide-conjugates-and-their-recognition-lectin-002372nas a2200277 4500008004100000022001400041245014600055210006900201260007100270300001600341490000600357520136000363653001301723653002501736653001301761653001201774653002301786653001801809100002901827700002601856700001901882700001701901700002701918700002201945856012701967 2014 eng d a1944-824400aSol-gel assisted fabrication of collagen hydrolysate composite scaffold: a novel therapeutic alternative to the traditional collagen scaffold0 aSolgel assisted fabrication of collagen hydrolysate composite sc a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP a15015-150250 v63 a

Collagen is one of the most widely used biomaterial for various biomedical applications. In this Research Article, we present a novel approach of using collagen hydrolysate, smaller fragments of collagen, as an alternative to traditionally used collagen scaffold. Collagen hydrolysate composite scaffold (CHCS) was fabricated with sol-gel transition procedure using tetraethoxysilane as the silica precursor. CHCS exhibits porous morphology with pore sizes varying between 380 and 780 mu m. Incorporation of silica conferred CHCS with controlled biodegradation and better water uptake capacity. Notably, 3T3 fibroblast proliferation was seen to be significantly better under CHCS treatment when compared to treatment with collagen scaffold. Additionally, CHCS showed excellent antimicrobial activity against the wound pathogens Staphylococcus aureus, Bacillus subtilis, and Escherichia coli due to the inherited antimicrobial activity of collagen hydrolysate. In vivo wound healing experiments with full thickness excision wounds in rat model demonstrated that wounds treated with CHCS showed accelerated healing when compared to wounds treated with collagen scaffold. These findings indicate that the CHCS scaffold from collagen fragments would be an effective and affordable alternative to the traditionally used collagen structural biomaterials.

10acollagen10acollagen hydrolysate10ascaffold10asol-gel10atissue engineering10awound Healing1 aRamadass, Satiesh, Kumar1 aPerumal, Sathiamurthi1 aGopinath, Arun1 aNisal, Anuya1 aSubramanian, Saravanan1 aMadhan, Balaraman uhttp://library.ncl.res.in/content/sol-gel-assisted-fabrication-collagen-hydrolysate-composite-scaffold-novel-therapeutic-001896nas 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

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.

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

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.

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-mechanism02081nas a2200217 4500008004100000245013100041210006900172260000800241300002500249490000600274520129300280100001701573700001901590700002001609700001801629700002101647700002301668700001801691700002601709856012801735 2018 eng d00aSilk fibroin micro-particle scaffolds with superior compression modulus and slow bioresorption for effective bone regeneration0 aSilk fibroin microparticle scaffolds with superior compression m cMAY aArticle Number: 72350 v83 aSilk fibroin (SF), a natural polymer produced by Bombyx mori silkworms, has been extensively explored to prepare porous scaffolds for tissue engineering applications. Here, we demonstrate, a scaffold made of SF, which exhibits compression modulus comparable to natural cancellous bone while retaining the appropriate porosities and interconnected pore architecture. The scaffolds also exhibit high resistance to in-vitro proteolytic degradation due to the dominant beta sheet conformation of the SF protein. Additionally, the scaffolds are prepared using a simple method of microparticle aggregation. We also demonstrate, for the first time, a method to prepare SF micro-particles using a Hexafluoroisopropanol-Methanol solvent-coagulant combination. SF microparticles obtained using this method are monodisperse, spherical, non-porous and extremely crystalline. These micro-particles have been further aggregated together to form a 3D scaffold. The aggregation is achieved by random packing of these microparticles and fusing them together using a dilute SF solution. Preliminary in-vitro cell culture and in-vivo implantation studies demonstrate that the scaffolds are biocompatible and they exhibit the appropriate early markers, making them promising candidates for bone regeneration.1 aNisal, Anuya1 aSayyad, Raeesa1 aDhavale, Prachi1 aKhude, Bhakti1 aDeshpande, Rucha1 aMapare, Vidhyashri1 aShukla, Swati1 aVenugopalan, Premnath uhttp://library.ncl.res.in/content/silk-fibroin-micro-particle-scaffolds-superior-compression-modulus-and-slow-bioresorption01669nas a2200205 4500008004100000022001400041245009800055210006900153260000800222300001600230490000700246520095900253100002201212700001501234700002101249700002101270700001701291700002601308856012901334 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

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.

1 aHirlekar, Swarali1 aRay, Debes1 aAswal, Vinod, K.1 aPrabhune, Asmita1 aNisal, Anuya1 aRavindranathan, Sapna uhttp://library.ncl.res.in/content/silk-fibroin-sodium-dodecyl-sulfate-gelation-molecular-structural-and-rheological-insights02433nas a2200277 4500008004100000022001400041245011600055210006900171260000900240300001200249490000800261520151600269653001501785653001501800653002801815653002701843653001501870653002001885100001801905700002101923700001701944700001701961700002201978700002402000856013102024 2020 eng d a0141-813000aStructural and physical analysis of underwater silk from housing nest composites of a tropical chironomid midge0 aStructural and physical analysis of underwater silk from housing cNOV  a934-9420 v1633 a

Chironomids are an abundant group of aquatic silk spinning insects. They offer a unique opportunity of silk harvestation without killing them; however, they remained underappreciated models in silk research. Here, we investigate the structural and biomechanical characteristics of silk from the midge, Chironomus ramosus. A combination of microscopic (SEM), spectroscopic (CD and IR), structural (XRD), thermal (DSC and TGA) and mechanical measurement tools and techniques were employed to gain critical insights on midge silk. Maximum yield of silk was obtained from Chironomus in similar to 2.5 h, the shortest time reported among insects. The network of water-insoluble silk fibres possessed the smallest diameter of 110 +/- 35 nm, known for any insect silk, qualifying its superiority in fibre fineness. We demonstrate a cruelty-free silk extraction method in contrast to the conventional violent techniques. Structural characterization indicated coexistence of various secondary conformations, beta sheets being predominant. We compare and contrast these features to well-characterized caddisfly and silk-worm silks and highlight the uniqueness in midge silk that render mechanical stability and potentially contribute to its multi-functionalization. We thus propose Chironomus as an emerging candidate of water-borne silk, especially in the context of the `Peace silk' industry, aiming to develop non-violent methods for silk harvestation from animals. (C) 2020 Elsevier B.V. All rights reserved.

10abiopolymer10aChironomus10aCommercial applications10aHousing nest composite10aPeace silk10aUnderwater silk1 aThorat, Leena1 aJoseph, Emmanuel1 aNisal, Anuya1 aShukla, Ekta1 aRaviKumar, Ameeta1 aNath, Bimalendu, B. uhttp://library.ncl.res.in/content/structural-and-physical-analysis-underwater-silk-housing-nest-composites-tropical-chironomid02492nas a2200289 4500008004100000245009100041210006900132260000800201300001100209520157300220653003001793653002201823653002101845653002101866653001001887653001901897653001601916653001301932653001701945100002101962700001801983700001902001700002202020700001702042700002602059856011702085 2021 eng d00aSilk fibroin and ceramic scaffolds: comparative in vitro studies for bone regeneration0 aSilk fibroin and ceramic scaffolds comparative in vitro studies  cAPR ae102213 a

Synthetic bone void fillers based on calcium ceramics are used to fill cavities in the bone and promote bone regeneration. More recently, silk fibroin (SF), a protein polymer obtained from Bombyx mori silkworm, has emerged as a promising material in bone void filling. In this work, we have compared the safety and efficacy of two types of silk fibroin-based bone void fillers with currently used and commercially available ceramic bone void fillers (based on calcium sulphate, beta tricalcium phosphate, and beta tricalcium phosphate with hydroxyapatite). Further, we have also evaluated these two types of SF scaffolds, which have strikingly different structural attributes. The biocompatibility of these scaffolds was comparable as assessed by cytotoxicity assay, cellular adhesion assay, and immunogenic assay. Ability of the scaffolds to support differentiation of human mesenchymal stem cells (hMSCs) into an osteoblastic lineage was also evaluated in an in vitro differentiation experiment using reverse transcriptase polymerase chain reaction analysis. These results revealed that cells cultured on SF scaffolds exhibit higher expression of early to late markers such as Runx2, BMPs, collagen, osterix, osteopontin, and osteocalcin as compared with ceramic-based scaffolds. This observation was further validated by studying the expression of alkaline phosphatase and calcium deposition. We also show that scaffolds made from same material of SF, but characterized by very different pore architectures, have diverse outcome in stem cell differentiation.

10abeta tricalcium phosphate10abone regeneration10abone void filler10acalcium sulphate10ahMSCs10ahydroxyapatite10aosteoblasts10ascaffold10aSilk fibroin1 aDeshpande, Rucha1 aShukla, Swati1 aSayyad, Raeesa1 aSalunke, Shalmali1 aNisal, Anuya1 aVenugopalan, Premnath uhttp://library.ncl.res.in/content/silk-fibroin-and-ceramic-scaffolds-comparative-vitro-studies-bone-regeneration02197nas a2200241 4500008004100000245009300041210006900134260000800203300001100211490000700222520140600229653001701635653002101652653002301673653002401696653001701720100002101737700001801758700002001776700001701796700001901813856012301832 2022 eng d00aSilk fibroin and recombinant elastin blend nano-coatings for implantable medical devices0 aSilk fibroin and recombinant elastin blend nanocoatings for impl cDEC a1048750 v333 a

Silicone breast implants are conventionally used to reconstruct the shape and size of the breast in breast cancer patients. However, rate of failure of implants due to formation of capsular contracture is significantly high. Recent studies have shown that coating the surface of the implant with a biocompatible polymer can mitigate this risk. Here, we have modified the surface of implant using a biocompatible natural biopolymer silk fibroin (SF). Further, we have developed formulations of SF with a recombinantly produced elastin-like-peptide (ELP) and compared their performance with a known anti-fouling hydrophilic polymer - polyethylene oxide (PEO). Microscopic and spectroscopic characterization confirm the formation of uniform coatings. These coatings have been also characterized for their ability to resists crack formation. Further, the coatings have been evaluated for their biological performance. Our studies show that addition of 25 wt% of ELP to SF significantly enhances the crack resistance for the coatings. In addition, SF/ELP coatings reduce the adsorption of blood plasma proteins by more than 80 %. Preliminary analysis shows that the SF/ELP blend coatings are non-cytotoxic and support adhesion, growth and proliferation of fibroblast cells. The study therefore demonstrates that SF/ELP coatings have the potential to mitigate the risk of breast implant failure.

10aBlood plasma10aCrack resistance10aProtein adsorption10aRecombinant elastin10aSilk fibroin1 aJoseph, Emmanuel1 aKane, Kartiki1 aParekh, Nimisha1 aNisal, Anuya1 aJanorkar, Amol uhttp://library.ncl.res.in/content/silk-fibroin-and-recombinant-elastin-blend-nano-coatings-implantable-medical-devices03054nas a2200289 4500008004100000022001400041245009800055210006900153260000800222300001400230490000600244520215300250653002102403653002202424653002102446653001402467653001002481653001202491653001702503100002102520700001802541700001502559700002302574700001702597700002602614856012402640 2022 eng d a2373-987800aSilk fibroin microparticle scaffold for use in bone void filling: safety and efficacy studies0 aSilk fibroin microparticle scaffold for use in bone void filling cMAR a1226-12380 v83 a

Silk fibroin (SF) is a natural biocompatible protein polymer extracted from cocoons of silkworm Bombyx mori. SF can be processed into a variety of different forms and shapes that can be used as scaffolds to support bone regeneration. Threedimensional (3D) SF scaffolds have shown promise in bone-void -filling applications. In in vitro studies, it has been demonstrated that a microparticle-based SF (M-RSF) scaffold promotes the differentiation of stem cells into an osteoblastic lineage. The expression of differentiation markers was also significantly higher for M-RSF scaffolds as compared to other SF scaffolds and commercial ceramic scaffolds. In this work, we have evaluated the in vitro and in vivo biocompatibility of M-RSF scaffolds as per the ISO 10993 guidelines in a Good Laboratory Practice (GLP)-certified facility. The cytotoxicity, immunogenicity, genotoxicity, systemic toxicity, and implantation studies confirmed that the M-RSF scaffold is biocompatible. Further, the performance of the MRSF scaffold to support bone formation was evaluated in in vivo bone implantation studies in a rabbit model. Calcium sulfate (CaSO4) scaffolds were chosen as reference material for this study as they are one of the preferred materials for bone-void -filling applications. M-RSF scaffold implantation sites showed a higher number of osteoblast and osteoclast cells as compared to CaSO4 implantation sites indicating active bone remodeling. The number density of osteocytes was double for M-RSF scaffold implantation sites, and these M-RSF scaffold implantation sites were characterized by enhanced collagen deposition, pointing toward a finer quality of the new bone formed. Moreover, the M-RSF scaffold implantation sites had a negligible incidence of secondary fractures as compared to the CaSO4 implantation sites (similar to 50% sites with secondary fracture), implying a reduction in postsurgical complications. Thus, the study demonstrates that the M-RSF scaffold is nontoxic for bone-void -filling applications and facilitates superior healing of fracture defects as compared to commercial calcium-based bone void fillers.

10aBiocompatibility10abiological safety10abone void filler10aISO 1099310aM-RSF10aSerioss10aSilk fibroin1 aDeshpande, Rucha1 aShukla, Swati1 aKale, Amod1 aDeshmukh, Narendra1 aNisal, Anuya1 aVenugopalan, Premnath uhttp://library.ncl.res.in/content/silk-fibroin-microparticle-scaffold-use-bone-void-filling-safety-and-efficacy-studies02284nas a2200277 4500008004100000022001400041245011300055210006900168260000800237300001200245490000800257520137100265653002801636653002101664653001001685653002801695653002501723100002001748700001901768700001801787700002001805700001701825700002201842700002001864856012201884 2022 eng d a0141-813000aSuperior processability of Antheraea mylitta silk with cryo-milling: performance in bone tissue regeneration0 aSuperior processability of Antheraea mylitta silk with cryomilli cJUL a155-1650 v2133 a

Non-mulberry silk polymers have a promising future in biomedical applications. However, the dissolution of nonmulberry silk fiber is a still challenge and this poor processability has limited the use of this material. Here, we report a unique protocol to process the Antheraea mylitta (AM) silk fiber. We have shown that the cryo-milling of silk fiber reduces the beta sheet content by more than 10% and results in an SF powder that completely dissolves in routine solvents like trifluoroacetic acid (TFA) within few hours to form highly concentrated solutions (\~20 wt %). Further, these solutions can be processed using conventional processing techniques such as electrospinning to form 3D scaffolds. Bombyx mori (BM) silk was used as a control sample in the study. In-vitro studies were also performed to monitor cell adhesion and proliferation and hMSCs differentiation into osteogenic lineage. Finally, the osteogenic potential of the scaffolds was also evaluated by a 4-week implantation study in rat calvarial model. The in-vitro and in-vivo results show that the processing techniques do not affect the biocompatibility of the material and the AM scaffolds support bone regeneration. Our results, thus, show that cryo-milling facilitates enhanced processability of non-mulberry silk and therefore expands its potential in biomedical applications.

10aBone tissue engineering10aCalvarial defect10ahMSCs10aNon-mulberry silk fiber10aProcessing technique1 aParekh, Nimisha1 aBijosh, C., K.1 aKane, Kartiki1 aPanicker, Alaka1 aNisal, Anuya1 aWangikar, Pralhad1 aAgawane, Sachin uhttp://library.ncl.res.in/content/superior-processability-antheraea-mylitta-silk-cryo-milling-performance-bone-tissue