01885nas a2200229 4500008004100000022001400041245011200055210006900167260006800236300001400304490000700318520107500325653001401400653001401414653001301428100001801441700002201459700001601481700001901497700001701516856012201533 2005 eng d a0021-899500aSwelling behavior and diffusion studies of high-water-retaining acrylamide/potassium methacrylate hydrogels0 aSwelling behavior and diffusion studies of highwaterretaining ac a111 RIVER ST, HOBOKEN, NJ 07030 USAbJOHN WILEY & SONS INCcMAY a1153-11640 v963 a

Poly(acrylamide-co-potassium methacrylate) hydrogels were prepared by free-radical simultaneous polymerization with aqueous solutions of acrylamide (AAm) and potassium methacrylate (KMA) with a redox initiator. The copolymerization was performed with eight different compositions of KMA at a fixed concentration of oil-soluble crosslinkers, including 1,4-butanediol diacrylate and ethylene glycol dimethacrylate (EGDMA). For every composition of AAm/KMA copolymer, the percentage swelling, swelling equilibrium, and diffusion characteristics were investigated. The copolymers were further studied for deswelling properties. The power law relationships of the hydrogels were evaluated for variation in terms of saline concentration. The AAm/KMA copolymers were confirmed by IR spectroscopy. Thermal studies of hydrogels were performed with differential scanning calorimetry and thermogravimetric analysis. EGDMA was found to be a better crosslinker for obtaining higher swelling and deswelling properties for the AAm/KMA hydrogels. (c) 2005 Wiley Periodicals, Inc.

10aDiffusion10ahydrogels10aswelling1 aMohan, Y., M.1 aMurthy, P., S. K.1 aRao, K., M.1 aSreeramulu, J.1 aRaju, K., M. uhttps://library.ncl.res.in/content/swelling-behavior-and-diffusion-studies-high-water-retaining-acrylamidepotassium-002511nas a2200265 4500008004100000022001400041245010000055210006900155260007600224300001400300490000800314520159500322653001401917653002201931653001901953653001701972653001901989100002002008700001802028700001902046700001702065700002502082700001702107856012102124 2011 eng d a0021-899500aMagnetic and electric responsive hydrogel-magnetic nanocomposites for drug-delivery application0 aMagnetic and electric responsive hydrogelmagnetic nanocomposites aCOMMERCE PLACE, 350 MAIN ST, MALDEN 02148, MA USAbWILEY-BLACKWELLcOCT a1364-13750 v1223 a

Magnetic and electrically responsive hydrogel networks were developed for drug-delivery applications. The hydrogel matrices were synthesized by the polymerization of acrylamide monomer in the presence of carboxymethylcellulose (CMC) or methylcellulose (MC) with N,N-methylenebisacrylamide, a crosslinker with the redox initiating system ammonium persulfate/tetramethylethylenediamine. The magnetic nanoparticles were generated throughout these hydrogel matrices by an in situ method by the incorporation of iron ions and their subsequent reduction with ammonia. A series of hydrogel-magnetic nanocomposites (HGMNCs) were developed with various CMC and MC compositions. The synthesized HGMNCs were characterized with spectral (Fourier transform infrared and ultraviolet-visible spectroscopy), X-ray diffraction, thermal, and microscopy methods. These HGMNCs contained iron oxide (Fe3O4) nanoparticles with an average particle size of about 22 nm, as observed by transmission electron microscopy. The dielectrical properties of the pure hydrogel (HG); the hydrogel loaded with iron ions, or the hydrogel iron-ion composite (HGIC); and the HGMNCs were measured. These results suggest that HGMNCs exhibited higher dielectric constants compared to HG and HGICs. The curcumin loading and release characteristics were also measured for HG, HGIC, and HGMNC systems. These data revealed that there was a sustained release of curcumin from HGMNCs because of the presence of magnetic nanoparticles in the hydrogel networks. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 122: 1364-1375, 2011

10ahydrogels10amagnetic polymers10aNanocomposites10ananoparticle10ananotechnology1 aReddy, Narayana1 aMohan, Murali1 aVaraprasad, K.1 aRavindra, S.1 aJoy, Pattayil, Alias1 aRaju, Mohana uhttps://library.ncl.res.in/content/magnetic-and-electric-responsive-hydrogel-magnetic-nanocomposites-drug-delivery-001955nas a2200241 4500008004100000022001400041245019800055210006900253260007300322300001200395490000800407520098500415653001401400653001401414653001901428653001801447653002201465100002001487700001901507700002501526700003001551856013201581 2012 eng d a0927-775700aGold nanoparticle embedded hydrogel matrices as catalysts: better dispersibility of nanoparticles in the gel matrix upon addition of N-bromosuccinimide leading to increased catalytic efficiency0 aGold nanoparticle embedded hydrogel matrices as catalysts better aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcNOV a296-3010 v4143 a

A simple and convenient method for generating and immobilizing gold NPs into polyethylene glycol-polyurethane (PEGPU) matrices is presented. The gold NP immobilized PEGPU (Au NP-PEGPU) hydrogel matrices are easy to handle and can be used as catalysts. The efficiency, reusability and durability of the Au NP-PEGPU catalyst matrices were investigated using the reduction of 4-nitroaniline (4NA) to p-phenylenediamine (p-PDA) by sodium borohydride in the presence of the catalyst as a test reaction. The Au NPs in the PEGPU matrix got aggregated after 3 cycles of catalysis but dispersion could be regenerated by the addition of N-bromosuccinimide (NBS). After this regeneration process the Au NPs-PEGPU matrix showed excellent efficiency without any aggregation, leaching or degradation. The reusability of the catalyst for 28 cycles yielding a total turnover number of 3220 and turn over frequency of 0.152 s(-1) is demonstrated. (C) 2012 Elsevier B.V. All rights reserved.

10acatalysis10ahydrogels10aImmobilization10aNanoparticles10aTurn over numbers1 aRamtenki, Vilas1 aAnumon, V., D.1 aBadiger, Manohar, V.1 aPrasad, Bhagavatula L. V. uhttps://library.ncl.res.in/content/gold-nanoparticle-embedded-hydrogel-matrices-catalysts-better-dispersibility-nanoparticles-001955nas a2200265 4500008004100000022001400041245010300055210006900158260007700227300001000304490000800314520100800322653001701330653001301347653002901360653001401389653001401403100002701417700001901444700002801463700002501491700002801516700002001544856012501564 2013 eng d a1022-136000aThermoresponsive and biodegradable dextran based microgels: synthesis and structural investigation0 aThermoresponsive and biodegradable dextran based microgels synth aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcJUL a27-340 v3293 a

Nanostructured objects, often ranging from hundreds of nanometers to few microns, support a number of functions directly linked to their structural features. They are, or they will be, protagonists in biomedical applications where miniaturized activities are required. These include the interface with living systems as tissues and cells, where targeted release of drug molecules occurs, or molecular imaging methods monitoring the drug trafficking in specific cell districts. The potentials of such devices, far to be fully understood, will be assessed only when a close correlation of their functions with their structure will be established. In this contribution we present a dextran based microdevice responsive to temperature and biodegradable. Both thermoresponsivity and biodegradability are of relevance for the potential use as drug carrier and controlled release device. The temperature behaviour, overall structure and internal architectures have been addressed with different methods.

10aBiomaterials10acolloids10adynamic light scattering10ahydrogels10ap(NiPAAm)1 aGhugare, Shivkumar, V.1 aChiessi, Ester1 aSakai, Victoria, Garcia1 aTelling, Mark, T. F.1 aWadgaonkar, Prakash, P.1 aParadossi, Gaio uhttps://library.ncl.res.in/content/thermoresponsive-and-biodegradable-dextran-based-microgels-synthesis-and-structural-002343nas a2200241 4500008004100000022001400041245008200055210006900137260006700206300001200273490000700285520151200292653001401804653001701818653002601835653001701861653001301878100002601891700002401917700002101941700002501962856011401987 2015 eng d a0959-810300aPorous poly(ethylene glycol)-polyurethane hydrogels as potential biomaterials0 aPorous polyethylene glycolpolyurethane hydrogels as potential bi a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcMAR a397-4040 v643 a

We report the synthesis of porous poly(ethylene glycol)-polyurethane (PEG-PU) hydrogels using PEG-4000 as a soft segment and 4,4-methylenebis(cyclohexylisocyanate) as a hard segment. The degree of swelling in the hydrogels could be controlled by varying the amount of crosslinking agent, namely 1,2,6-hexanetriol. Structural characterization of the hydrogels was performed using solid-state C-13 NMR and Fourier transform infrared spectroscopy. Wide-angle X-ray diffraction studies revealed the existence of crystalline domains of PEG and small-angle X-ray scattering studies showed the presence of lamellar microstructures. For generating a porous structure in the hydrogels, cryogenic treatment with lyophilization was used. Scanning electron microscopy and three-dimensional micro-computed tomography imaging of the hydrogels indicated the presence of interconnected pores. The mechanical strength of the hydrogels and xerogels was measured using dynamic mechanical analysis. The observed dynamic storage moduli (E) for the equilibrium swollen and dry gels were found to be 0.15 and 4.2 MPa, respectively. Interestingly, the porous PEG-PU xerogel also showed E of 5.6 MPa indicating a similar mechanical strength upon incorporating porosity into the gel matrix. Finally, preliminary cytocompatibility studies showed the ability of cells to proliferate in the hydrogels. These gels show promise for applications as scaffolds and implants in tissue engineering. (c) 2014 Society of Chemical Industry

10ahydrogels10apermeability10apoly(ethylene glycol)10apolyurethane10aporosity1 aDivakaran, Anumon, V.1 aTorris, Arun, A. T.1 aLele, Ashish, K.1 aBadiger, Manohar, V. uhttps://library.ncl.res.in/content/porous-polyethylene-glycol-polyurethane-hydrogels-potential-biomaterials-002264nas a2200361 4500008004100000022001400041245010900055210006900164260000800233300001300241490000800254520117500262653002201437653001301459653001201472653001401484653001701498653001301515653002901528653001401557653001201571653002101583653002401604653001701628653001301645653001401658100001801672700001901690700002501709700001701734700002101751856013001772 2017 eng d a0032-386100a Design and development of trivalent aluminum ions induced self healing polyacrylic acid novel hydrogels0 aDesign and development of trivalent aluminum ions induced self h cSEP a 196-2050 v1263 a

Development of ionically crosslinked superabsorbent polyacrylic acid (PAA) self-healing hydrogels using trivalent aluminum ions was investigated. The PAA hydrogels exhibited excellent self-healing behavior depending on the amount of the aluminum within the matrix. The migration of these ions within the polymer matrix was responsible for the physical crosslinking of the hydrogel and the origin of self healing ability. The PAA-Al hydrogels were insoluble in water and exhibited significantly high degree of swelling (similar to 4000%). Hydrogel also exhibited good mechanical properties with high level of elongation. Excellent self-healing efficiency was observed under dynamic as well as oscillatory Theological measurements. The presence of Al ions within PAA hydrogel facilitated the self-healing ability because of the ionic interaction in these gels which plays the key role of dynamic reversible sacrificial bonds which reforms upon reversal of the deformative force. (C) 2017 Elsevier Ltd. All rights reserved.

10aAluminum chloride10aBehavior10aComplex10aComposite10acrosslinking10aDelivery10aHigh-Mechanical Strength10ahydrogels10aNetwork10aPolyacrylic acid10aPolymeric Materials10aSelf-healing10aswelling10aTough; pH1 aAnjum, Sadiya1 aGurave, Pramod1 aBadiger, Manohar, V.1 aTiwari, Neha1 aGupta, Bhuvanesh uhttps://library.ncl.res.in/content/design-and-development-trivalent-aluminum-ions-induced-self-healing-polyacrylic-acid-novel02178nas a2200241 4500008004100000022001400041245011600055210006900171260000800240300001200248490000700260520139300267653001201660653001301672653001401685653002001699653001301719100002301732700001801755700002101773700001801794856012401812 2021 eng d a0959-810300aInjectabledextran-fluorenylmethoxycarbonylphenylalanine composite hydrogels with improved mechanical properties0 aInjectabledextranfluorenylmethoxycarbonylphenylalanine composite cFEB a222-2290 v703 a

Low molecular weight hydrogels are recently gaining importance owing to their applications in material sciences and biology. A new class of composite hydrogel was developed using polysaccharides such as dextran and fluorenylmethoxycarbonyl phenylalanine (FmocF) in a phosphate buffer. The molecular weight and concentration of the dextran were varied to obtain rigid but injectable hydrogels without using other crosslinking agents. From the different molecular weights of dextran studied (5k, 40k and 70k), a combination of FmocF (0.6% w/v) and dextran 40k (0.012% w/v) composite gels yielded a maximum value of storage modulus of approximately 1500 Pa, which is 3.5 times higher than the storage modulus of pure FmocF gels. Scanning electron microscopy of FmocF/dextran composite gels revealed highly tangled fibrous structures with dense branches and lower fiber diameter compared to pure FmocF gels. The high-intensity hydrogen-bonded N-H peak in the infrared spectra showed enhanced hydrogen bonding in FmocF/dextran composite gels compared to pure FmocF gels. The dextran acts as an impurity in the process of fibrillation, leading to a crystallographic mismatch, and densely packed thin fibers are formed. These gels exhibited gel to sol and sol to gel conversion with temperature or external stress and showed injectable behavior. (c) 2020 Society of Industrial Chemistry

10aDextran10aFmoc-Phe10ahydrogels10ainjectable gels10aRheology1 aAbraham, Jancy, N.1 aJoseph, Seena1 aTrivedi, Rishabh1 aKarle, Mrunal uhttps://library.ncl.res.in/content/injectabledextran-fluorenylmethoxycarbonylphenylalanine-composite-hydrogels-improved02394nas a2200265 4500008004100000022001400041245016000055210006900215260000800284490000700292520144100299653002401740653001401764653003601778653001801814653001801832100002201850700001601872700001901888700002201907700002101929700002601950700002501976856012702001 2023 eng d a1616-518700aSelf-assembled amino acid microstructures as biocompatible physically unclonable functions (BPUFs) for authentication of therapeutically relevant hydrogels0 aSelfassembled amino acid microstructures as biocompatible physic cNOV0 v233 a

Counterfeited biomedical products result in significant economic losses and pose a public health hazard for over a million people yearly. Hydrogels, a class of biomedical products, are being investigated as alternatives to conventional biomedical products and are equally susceptible to counterfeiting. Here, a biocompatible, physically unclonable function (BPUF) to verify the authenticity of therapeutically relevant hydrogels are developed. The principle of BPUF relies on the self-assembly of tyrosine into fibril-like structures which are incorporated into therapeutically relevant hydrogels resulting in their random dispersion. This unclonable arrangement leads to distinctive optical micrographs captured using an optical microscope. These optical micrographs are transformed into a unique security code through cryptographic techniques which are then used to authenticate the hydrogel. The temporal stability of the BPUFs are demonstrated and additionally, exploit the dissolution propensity of the structures upon exposure to an adulterant to identify the tampering of the hydrogel. Finally, a platform to demonstrate the translational potential of this technology in validating and detecting tampering of therapeutically relevant hydrogels is developed. The potential of BPUFs to combat hydrogel counterfeiting is exemplified by its simplicity in production, ease of use, biocompatibility, and cost-effectiveness.

10aanti-counterfeiting10ahydrogels10aphysically unclonable functions10aSelf-assembly10atranslational1 aAkavaram, Vishwas1 aKumar, Kush1 aSriram, Shreya1 aNarra, Saisrinath1 aKumawat, Akshant1 aMeena, Santosh, Kumar1 aPushpavanam, Karthik uhttps://library.ncl.res.in/content/self-assembled-amino-acid-microstructures-biocompatible-physically-unclonable-functions