17 research outputs found
Nanocapsules with stimuli-responsive moieties for controlled release employing light and enzymatic triggers
No full textThe development of stimuli-responsive nanomaterials, that possess tailored functional properties for the release of specific compounds, is of particular interest. To this extent, controlling the release of molecules at the desired target is an important parameter to regulate chemical and/or biological reactions at a more profound level in a wide variety of applications. In the present work, we report on the development of dual-responsive thiourethane-urethane nanocapsules synthesizedviaan interfacial polymerization reaction executed at the droplet interface using the inverse miniemulsion technique. Evidenceviamorphological and controlled release investigations indicate that our nanocapsules are able to encapsulate hydrophilic compounds with high efficiency in their aqueous core and allow for its selective release upon exposure to UV light and the enzyme esterase. Moreover, we demonstrate the efficient encapsulation of the fragrance molecule geranyl acetate and the anticancer drug doxorubicin. For the latter, we demonstrate its apoptotic effect after being released in MCF 7 breast cancer cells. Overall, these nanocapsules can be used for a wide variety of applications where a selective release of the payload is desired.S. S. is an SB PhD Fellow at the FWO (Research Foundation Flanders). S. K. P. acknowledges BOF funding from Hasselt University. This work is supported by Hasselt University and the Research Foundation Flanders (FWO Vlaanderen; Hercules project AUHL/15/2 - GOH3816N). The authors are thankful to Prof. M. Van Bael for access to the DLS device.Pramanik, SK; Ethirajan, A (corresponding author), Hasselt Univ, Inst Mat Res IMO, Wetenschapspk 1 & Agoralaan D, B-3590 Diepenbeek, Belgium; IMEC, Associated Lab IMOMEC, Wetenschapspk 1, B-3590 Diepenbeek, Belgium;
CSIR Cent Salt & Marine Chem Res Inst, Bhavnagar 364002, Gujarat, India.
[email protected]; [email protected]
PEGylating poly(p-phenylene vinylene)-based bioimaging nanoprobes
No full textHypothesis: Conjugated polymer nanoparticles (CNPs) have attracted considerable attention within bioimaging due to their excellent optical properties and biocompatibility. However, unspecific adsorption of proteins hampers their effective use as advanced bioimaging probes. Controlled methodologies made possible tailor-made functional poly(p-phenylene vinylene), enabling one-pot synthesis of CNPs containing functional surface groups. Hence, it should be feasible to PEGylate these CNPs to tune the uptake by cell lines representative for the brain without imparting their optical properties. Experiments: CNPs consisting of the statistical copolymer 2-(50-methoxycarbonylpentyloxy)-5-methoxy-1,4-phenylenevinylene and poly(2-methoxy-5-(30,70-dimethoxyoctyloxy)-1,4-phenylenevinylene) were fabricated by miniemulsion solvent evaporation technique. Surface carboxylic acid groups were used to covalently attach amine-terminated polyethylene glycol (PEG) of different molecular weights. We investigated the effect of grafting CNPs with PEG chains on their intrinsic optical properties, protein adsorption behavior and uptake by representative brain cell lines. Findings: PEGylation did not affect the optical properties and biocompatibility of our CNPs. Moreover, a significant decrease in protein corona formation and unspecific uptake in central nervous system cell lines, depending on PEG chain length, was observed. This is the first report indicating that PEGylation does not affect the CNPs role as excellent bioimaging tools and can be adapted to tune biological interactions with brain cells. (C) 2020 Elsevier Inc. All rights reserved.Support for confocal microscopy was given by Prof. dr. Marcel Ameloot and Dr. Hannelore Bove. Cells were kindly provided by Prof. dr. Annelies Bronckaers, Dr. Jo Mailleux and dra. Jasmine Vanmol. Technical support was given by Huguette Penxten, Christel Bocken and Erik Royackers. Dr. Neomy Zaquen is acknowledged for the synthesis of the conjugated polymers. MP is grateful for funding from the IWT (Agentschap voor Innovatie door Wetenschap en Technologie). SS is an SB PhD Fellow at the Research Foundation Flanders (FWO). The work was funded by the Belgian Charcot Foundation. TJ is grateful for funding from the FWO in the form of an Odysseus grant. This work was supported by Hasselt University and the Research Foundation Flanders (FWO Vlaanderen; Hercules project AUHL/15/2 -GOH3816N). Additional support from BELSPO in the form of the interuniversity attraction pole (IAP) program P7/05: Functional Supramolecular Systems is kindly acknowledged. We further acknowledge the Hercules Foundation for the project (LC-MS@UHasselt: Linear Trap QuadrupoleOrbitrap mass spectrometer.Ethirajan, A (corresponding author), Hasselt Univ, Inst Mat Res, Wetenschapspk 1, B-3590 Diepenbeek, Belgium.
[email protected]
Redox-Responsive Nanocapsules for the Spatiotemporal Release of Miltefosine in Lysosome: Protection against Leishmania
No full textLeishmaniasis, a vector-borne disease, is caused by intracellular parasite Leishmania donovani. Unlike most intracellular pathogens, Leishmania donovani are lodged in parasitophorous vacuoles and replicate within the phagolysosomes in macrophages. Effective vaccines against this disease are still under development, while the efficacy of the available drugs is being questioned owing to the toxicity for nonspecific distribution in human physiology and the reported drug-resistance developed by Leishmania donovani. Thus, a stimuli-responsive nanocarrier that allows specific localization and release of the drug in the lysosome has been highly sought after for addressing two crucial issues, lower drug toxicity and a higher drug efficacy. We report here a unique lysosome targeting polymeric nanocapsules, formed via inverse mini-emulsion technique, for stimuli-responsive release of the drug miltefosine in the lysosome of macrophage RAW 264.7 cell line. A benign polymeric backbone, with a disulfide bonding susceptible to an oxidative cleavage, is utilized for the organelle-specific release of miltefosine. Oxidative rupture of the disulfide bond is induced by intracellular glutathione (GSH) as an endogenous stimulus. Such a stimuli-responsive release of the drug miltefosine in the lysosome of macrophage RAW 264.7 cell line over a few hours helped in achieving an improved drug efficacy by 200 times as compared to pure miltefosine. Such a drug formulation could contribute to a new line of treatment for leishmaniasis.A. Das acknowledges SERB (India) Grants (CRG/2020/000492 and JCB/2017/000004) and DBT Grant (BT/PR22251/NNT/28/1274/2017) for supporting this research. N. Mukherjee acknowledges SERB (India) Grant PDF/2016/001437 and K. Das acknowledges the grant EMR/2015/001674 for supporting this research. Financial support from DST (DST/INSPIRE/03/2017/002477) is acknowledged by R.T. This manuscript bears CSMCRI registration no 7/2021.Pramanik, SK (corresponding author), CSIR Cent Salt & Marine Chem Res Inst, Bhavnagar 364002, Gujarat, India.
Mukherjee, N (corresponding author), CSIR Indian Inst Chem Biol, Canc Biol & Inflammatory Disorder Div, Kolkata 700032, India.
Chattopadhy, S (corresponding author), BITS Pilani, Pilani 403726, Goa, India.
Das, A (corresponding author), Indian Inst Sci Educ & Res Kolkata, Mohanpur 741246, W Bengal, India.
[email protected]; [email protected]; [email protected]
Effect of diallyl disulphide on hepatic glucose regulating enzymes in diabetic rats
Get PDF567-571This study examines whether the glucose regulating enzymes mediate hypoglycaemic effect of diallyl disulphide (DADS) since the biochemical mechanisms by which the latter regulates hepatic glucose-metabolizing enzymes remain unknown. Hepatic hexokinase, glucose-6-P-D and pyruvate kinase are the important glucose metabolising enzymes that control blood glucose homeostasis and considered to be potential targets for antidiabetic drugs. DADS is an important phytoconstituent of garlic (Allium sativum Linn.) which has been reported to possess hypoglycaemic effect. Diabetes was induced in rats by alloxan and the diabetic rats were given DADS for 30 days and the effect was compared with the standard hypoglycaemic drug metformin. The levels of blood glucose and insulin were measured using spectrophotometer and by ELISA method respectively. Activities of hepatic hexokinase, glucose-6-PD, and pyruvate kinase enzymes in hepatic tissues were measured in DADS and metformin treated diabetic rats. DADS significantly reduced the level of blood glucose and simultaneously augmented those of insulin, pyruvate kinase, hexokinase and glucose-6-PD enzyme activities almost similar to metformin. The hypoglycaemic effect of this compound may be explained, in part, by its inhibition of these enzyme activities and improved hepatic glucose utilization. This observation offers scope for new therapeutic approach in treating diabetes particularly in insulin- resistant cases
Safety evaluation of an antiviral polyherbal drug of Siddha Medicine in Wistar rats
Get PDFA polyherbal formulation Nila Vembu Kudineer (NVK) is traditionally used in the Siddha medicine to treat variety of fevers and related illness. This preparation is also claimed to be useful in the treatment of Dengue and Chickungunya. However, information on its safety and effect on vital organs on prolonged consumption is still lacking. Hence, an attempt had been made to evaluate the safety profile of NVK by investigating its effect on hematology, biochemistry, antioxidant status and histopathology of vital organs of Wistar rats. Three groups of rats (n=4) were considered for the study. Group I rats served as control that received only food and water. Group II and III rats were orally administered with freshly prepared NVK decoction at400 and 800 mg/kg body weight respectively for 28 consecutive days. The body weights were monitored daily and on day 29, overnight fasted animals were sacrificed and the blood was collected to study hematological profile, hepato-renalmarkers and antioxidant parameters. The tissues of liver and kidney were subjected to histopathological examination. Sub-chronic administration of NVK in lower dose to rats did not produce any significant changes in body and organ weights. The hematological parameters as well as hepatic and renaltoxicity markers also showed no significant changes in lower dose. However, with higher dose of NVK, mild sinusoidal congestion and dilatation were noticed in liver tissues while significant elevation of urea in the serum and hydrophic changes in kidney architecture was observed in tissues. The results of the study indicated safety of NVK in the lower dose and possibility of nephrotoxicity with increase in dosage and duration
ChemInform Abstract: Gangetial, a New Pterocarpan from the Roots of Desmodium gangeticum
No full textComposition and antibacterial activities of volatile oil of Millingtonia hortensis flowers from Sultanate of Oman
No full textCentral Instrumentation Laboratory, College of Agricultural and Marine Sciences,
Sultan Qaboos University, P.O. Box 34, P.C. 123, Muscat, Sultanate of Oman
E-mail : [email protected]
Department of Biology, College of Science, Sultan Qaboos University, P.O. Box 36, P.C. 123, Muscat,
Sultanate of Oman
E-mail : [email protected]
Department of Research, Saveetha University, Thandalam, Chennai-602 105, India
E-mail : [email protected]
Manuscript received online 02 March 2016, accepted 12 February 2017
Millingtonia hortensis commonly known as Tree Jasmine or Indian Cork Tree, is indigenous to Burma and the Malay Archipelago and cultivated as an ornamental plant in some countries. The flowers, root and bark are used medicinally. In this study, the volatile oil (VO) obtained by the hydro-distillation of the flowers of the plant grown in Sultanate of Oman, has been analyzed by GC-MS. A total of 32 compounds have been identified that formed major part (97.7%) of the volatile oil. The main components of VO were L-linalool (29.16%), α-farnesene (11.80%), nerolidol (11.34%), pentacosane (9.69%), 1-octen-3-ol (7.62%), (e)-isoeugenol (4.87%), α-terpineol (3.82%), linalool oxide (3.68%), heptacosane (3.03%) and tricosane (2.63%). The volatile oil has been tested for its antimicrobial activity against eleven bacteria wherein it exhibited significant inhibition against seven, moderate against two and no response against two strains. The minimum inhibitory concentration (MIC) has also been determined for the volatile oil
Effect of Naga Parpam, a metallic drug of Siddha medicine, on lipid peroxidation, antioxidant enzymes and tissues of liver in Wistar rats
No full text420-422Naga Parpam (NP), a zinc containing drug is prescribed in
Siddha medicine to treat piles, fistula, dysentery, diarrhoea and
tuberculosis. In this investigation, NP’s effect on lipid
peroxidation, antioxidant enzymes and tissues of liver in Wistar
rats has been studied. The drug was administered orally in doses
of 5, 10 and 20 mg/kg body weight for 28 days to the
experimental animals. On day 29, they were sacrificed and the
liver was removed. From the liver homogenate, lipid peroxidation
(LPO) and the activities of antioxidant enzymes (catalase,
superoxide dismutase and glutathione peroxidase) were analyzed.
Dose dependent decrease in LPO and increase in the above
enzymes revealed its potential antioxidant activity. There were no
significant changes in the liver tissue architecture in histology that
further confirmed the pro-active role of NP in treating diseases
Moringa oleifera seeds attenuate benzene-induced alterations in lipid peroxidation and antioxidant enzymes in liver and kidney tissues of Wistar rats
Get PDFBenzene is a notorious toxicant that is responsible for a host of diseases including leukemia. Its concentration in the environment is increasing day-by-day due to excessive automobile use, accelerated industrial activities and cigarette smoke. The awareness on the harmful effects of benzene on health is limited and no antidote has been reported yet. In this study, an attempt has been made to find out a suitable remedy to overcome benzene toxicity in a living organism from a natural source with the seeds of the plant Moringa oleifera (MO). Thirty six Wistar rats were considered for the study and divided into six groups (n=6). While group I remained as control with normal animals, those in groups II – VI received benzene by oral route (800 mg/kg body weight) for 28 consecutive days. On day 29, the benzene-treated animals in groups III – VI received respectively the standard drug ascorbic acid (AA, 25 mg/kg body weight) and MO (50, 100 and 200 mg/kg body weight) for the following 7 days. Group II rats that received only benzene served as negative control without any treatment. On day 36, all the animals were sacrificed and vital organs liver and kidney were removed for studying lipid peroxidation (LPO) and antioxidant markers [Superoxide dismutase (SOD), Total reduced glutathione (TRG), Glutathione peroxidase (GPx) and Catalase (CAT)] in addition to histopathological changes in the tissues. The results of the study revealed that significant changes occurred in the above parameters due to benzene dosing to animals were reverted to near normal values on MO administration in the liver and kidney tissues as compared to untreated animals, suggesting MO’s pro-active role in attenuating benzene toxicity
Flow field behavior with Reynolds number variance around a spiked body
No full textAn experimental visualization study was performed to investigate the dependence of the pressure hill height and the influence zone expanse, for flow past a spiked body with different nose configurations, over a Reynolds number range from 2278 to 4405 to establish the vortex shedding process, and applicability in low speed flow regime for effective pressure reduction. It is found that the spike reduces the radius of curvature of the approaching streamline, leading to the deflection of the streamlines towards the shoulder of the basic body, resulting in a narrow zone of the positive pressure hill at the body nose. It is also observed that the pressure hill length and the influence zone expanse decrease with the introduction of spike over the present range of Reynolds numbers. For Reynolds numbers less than 2700, spike with conical nose is found to be more efficient than the spikes with other nose shapes of the present study in reducing the positive pressure at the nose of the blunt body. For higher Reynolds numbers, greater than 2700, the size of the vortex at the junction of the spike and basic body is the largest for the spike with hemispherical nose, and emerges as a potential candidate for application in possible wind-design resistant structures.Japanese Government's MEXT ScholarshipSCI(E)[email protected]; [email protected]; [email protected]
