01289nas a2200217 4500008004100000022001400041245008300055210006900138260010200207300001400309490000700323520047000330653001100800653002500811653002600836653002200862100002200884700002000906700003000926856011500956 2008 eng d a0011-389100aTunable surface modification of silica nanoparticles through `click' chemistry0 aTunable surface modification of silica nanoparticles through cli aC V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIAbINDIAN ACAD SCIENCEScNOV a1327-13330 v953 a

Tuning the surface functionality of silica nanoparticles through a `click' chemistry-based protocol is demonstrated. Pyrene, a fluorophore that displays excimer emission specifically at higher density/concentration is chosen for highlighting the fidelity of surface functionalization. The UV-visible absorbance of the pyrene chromophore capping the nanoparticle is used to determine the amount of pyrene units present on the surface of a silica nanoparticle.

10apyrene10asilica nanoparticles10asurface functionality10a`Click' chemistry1 aChandran, Prathap1 aHotha, Srinivas1 aPrasad, Bhagavatula L. V. uhttps://library.ncl.res.in/content/tunable-surface-modification-silica-nanoparticles-through-click-chemistry-002661nas a2200253 4500008004100000022001400041245017300055210006900228260000800297300001100305490000800316520177800324653001502102653001202117653002502129653001202154100001702166700001702183700002002200700001902220700002102239700002202260856012502282 2021 eng d a0927-776500aDesign and synthesis of a new topical agent for halting blood loss rapidly: a multimodal chitosan-gelatin xerogel composite loaded with silica nanoparticles and calcium0 aDesign and synthesis of a new topical agent for halting blood lo cFEB a1114540 v1983 a

Uncontrolled hemorrhage often causes death during traumatic injuries and halting exsanguination topically is a challenge. Here, an efficient multimodal topical hemostat was developed by (i) ionically crosslinking chitosan and gelatin with sodium tripolyphosphate for (ii) fabricating a robust, highly porous xerogel by lyophilization having 86.7 % porosity, by micro-CT and large pores similar to 30 mu m by SEM (iii) incorporating 0.5 mg synthesized silica nanoparticles (SiNPs, 120 nm size, -22 mV charge) and 2.5 mM calcium in xemgel composite that was confirmed by FTIR analysis with peaks at 3372, 986 and 788 cm(-1), respectively. XPS analysis displayed the presence of SiNPs (Si2p peak for silicon) and calcium (Ca2p1, Ca2p3 transition peaks) in the composite. Interestingly, in silico percolation simulation for composite revealed interlinked 800 mu m long-conduits predicting excellent absorption capacity and validated experimentally (640 % of composite dry weight). The composite achieved >16-fold improved blood clotting in vitro than commercial Celox and Gauze through multimodal interaction of its components with RBCs and platelets. The composite displayed good platelet activation and thrombin generation activities. It displayed high compressive strength (2.45 MPa) and withstood pressure during application. Moreover, xerogel composite showed high biocompatibility. In vivo application of xerogel composite to lethal femoral artery injury in rats achieved hemostasis (2.5 min) significantly faster than commercial Celox (3.3 min) and Gauze (4.6 min) and was easily removed from the wound. The gamma irradiated composite was stable till 1.5 yr. Therefore, the xerogel composite has potential for application as a rapid topical hemostatic agent.

10aHemostatic10aPolymer10asilica nanoparticles10aXerogel1 aPatil, Gokul1 aTorris, Arun1 aSuresha, P., R.1 aJadhav, Sachin1 aBadiger, Manohar1 aGhormade, Vandana uhttps://library.ncl.res.in/content/design-and-synthesis-new-topical-agent-halting-blood-loss-rapidly-multimodal-chitosan02223nas a2200241 4500008004100000022001400041245010900055210006900164260000900233490000700242520136600249653003501615653001601650653001201666653002401678653002501702100001501727700002801742700003501770700002001805700003101825856012501856 2025 eng d a1439-423500aTailoring of rheological properties through hydrophobic interactions in silica-based liquid crystal gels0 aTailoring of rheological properties through hydrophobic interact cNOV 0 v263 a

Modification of the intrinsic hydrophilic character of the pristine silica nanoparticles (SiNP) decorated with silanol moieties into a hydrophobic state has been of substantial interest, owing to the amenability to gelation of desirable liquids. Many reports exist on composites of SiNP with liquid crystals (LCs), an epitome of anisotropic soft matter. The fumed SiNP, unlike its precipitated counterpart, has been the preferred variety. A family of colloidal gel systems is reported, consisting of precipitated SiNP in a nematic LC, formed by substituting some native silanols with methyl, butyl, or dodecane chains. Detailed steady state and oscillatory rheological measurements are performed, along with analyses using the soft glass and other viscoelastic models. The study demonstrates that the sophisticated modified fractional models, Kelvin-Voight and Maxwell, proposed for generalized viscoelastic behavior of soft materials, are quite successful in describing these nematic gels as well. The observed nontrivial relationship between the ligand length and the strength of the gel network is elucidated on the basis of a judicious combination of the van der Waals, hydrogen bonding, and hydrophobic interactions, leading to a detailed understanding of the viscoelastic behavior of the composites and the influence of SiNP surface chemistry.

10afractional viscoelastic models10aHydrophobic10anematic10arheological studies10asilica nanoparticles1 aSumana, S.1 aChakrabortty, Pratyasha1 aKarumuthil, Subash, Cherumanni1 aPrasad, Krishna1 aPrasad, Bhagavatula, L. V. uhttps://library.ncl.res.in/content/tailoring-rheological-properties-through-hydrophobic-interactions-silica-based-liquid