01609nas a2200205 4500008004100000022001400041245004500055210004200100260007100142300001400213490000700227520095400234100002101188700002101209700002501230700002401255700002101279700002301300856008001323 2015 eng d a0024-929700aStar telechelic poly(L-lactide) ionomers0 aStar telechelic polyLlactide ionomers a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP a6580-65880 v483 a

Poly(L-lactide) (PLA), a biodegradable and biorenewable polymer, has many excellent properties that are equivalent to those of petroleum-derived plastics such as polystyrene, aromatic polyesters, etc. However, a major disadvantage of PLA which limits its processability is its poor melt elasticity. In this work we explore the possibility of improving the viscoelastic properties of PLA melt by incorporating ionic groups on the polymer. Specifically, we demonstrate the synthesis of star telechelic PLA anionomers by a three-step procedure involving synthesis of Star PIA, converting the hydroxyl end groups into carboxylic acid end groups, and finally converting these into ionic groups. Rheology data showed a dramatic increase in the elasticity of the star telechelic ionomer melts relative to the Star PLA melts. The viscoelasticity of star telechelic ionomers melts could be modulated by varying the number of ionic groups per molecule.

1 aKulkarni, Amruta1 aLele, Ashish, K.1 aSivaram, Swaminathan1 aRajamohanan, P., R.1 aVelankar, Sachin1 aChatterji, Apratim uhttps://library.ncl.res.in/content/star-telechelic-polyl-lactide-ionomers-002227nas a2200265 4500008004100000022001400041245014100055210006900196260007300265300001200338490000700350520126500357653001201622653001701634653001401651100001701665700002101682700002201703700001801725700001901743700001701762700002701779700002501806856013001831 2015 eng d a0141-813000aZinc inhibits glycation induced structural, functional modifications in albumin and protects erythrocytes from glycated albumin toxicity0 aZinc inhibits glycation induced structural functional modificati aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG a601-6100 v793 a

The present work aims to investigate the concentration and time dependant effect of zinc on the in vitro non enzymatic modifications of albumin by diabetic levels of glucose. Further, preventive and curative effect of zinc was studied by adding zinc before and after initiation of glycation respectively. Glycation of albumin was done at different concentrations of zinc (125, 250 and 500 mu M) at different time intervals (21,28 and 35 days) with appropriate controls. The antiglycation potential of zinc was assessed by estimating different markers of albumin glycation (fructosamines, carbonyls, bound sugar, AGEs), structural modifications (free amino, thiol group, beta amyloid, native PAGE, ANS binding, fluorescence lifetime decay and CD analysis) and functional properties (antioxidant activity, hemolysis). Zinc at highest concentration (500 mu M) significantly reduced modifications of albumin which was comparable to aminoguanidine and also protected secondary and tertiary structure of albumin after 28 days of incubation. Zinc exhibited significant protective effect on erythrocytes by inhibiting hemolysis. Thus the present study indicate preventive mode of albumin glycation inhibition by zinc. (C) 2015 Elsevier B.V. All rights reserved.

10aAlbumin10aErythrocytes10aGlycation1 aTupe, Rashmi1 aKulkarni, Amruta1 aAdeshara, Krishna1 aSankhe, Neena1 aShaikh, Shamim1 aDalai, Sayli1 aBhosale, Siddharth, H.1 aGaikwad, Sushama, M. uhttps://library.ncl.res.in/content/zinc-inhibits-glycation-induced-structural-functional-modifications-albumin-and-protects-002012nas a2200205 4500008004100000022001400041245009700055210006900152260000800221300001100229490000800240520133000248653002001578653001201598653002201610653001701632653001501649100002101664856012101685 2022 eng d a0032-386100aEffect of ionic interactions on crystallization of star telechelic poly (L-lactide) ionomers0 aEffect of ionic interactions on crystallization of star telechel cJUN a1249390 v2523 a

Effect of ionic interactions on crystallization properties of star telechelic poly(L-lactide) ionomers was studied by performing isothermal crystallization experiments. We report a comparison between star PLLA and star telechelic PLLA ionomer. It was evident that the ionic interactions in the ionomer affected the crystallization rate as well as modified the spherulitic morphology. Employing Avrami analysis on the isothermal crystallization data we show that star PLLA shows faster crystallization at higher temperatures (closer to melting point) than the star PLLA ionomer. However, a reversal of this trend in crystallization is observed at lower temperatures (closer to glass transition temperature). The origin of high temperatures behaviour comparison is explained in terms of the higher secondary nucleation barrier for ionomers using the famous Lauritzen- Hoffman secondary nucleation theory. However, we point out that the assumption of equal diffusion barrier in this theory limits its range of applicability. In order to explain the low temperature behaviour, we invoke the activation energy comparison in PLLA and ionomer using rheological studies. We show that although the presence of ions in the polymer impede the secondary nucleation process, its effect is only observed at higher temperatures.

10aCrystallization10aIonomer10aPoly( L -lactide)10aStar polymer10aTelechelic1 aKulkarni, Amruta uhttps://library.ncl.res.in/content/effect-ionic-interactions-crystallization-star-telechelic-poly-l-lactide-ionomers