Browsing by Author "Manju, S."

Now showing 1 - 7 of 7
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    Conjugation of curcumin onto hyaluronic acid enhances its aqueous solubility and stability
    (JOURNAL OF COLLOID AND INTERFACE SCIENCE, 2011)
    Polymer-drug conjugates have gained much attention largely to circumvent lower drug solubility and to enhance drug stability. Curcumin is widely known for its medicinal properties including its anticancer efficacy. One of the serious drawbacks of curcumin is its poor water solubility which leads to reduced bio-availability. With a view to address these issues, we synthesized hyaluronic acid-curcumin (HA-Cur) conjugate. The drug conjugate was characterized using FT-IR, NMR, Dynamic light scattering and TEM techniques. The conjugates, interestingly found to assembles as micelles in aqueous phase. The formation of micelles seems to improve the stability of the drug in phisiological pH. We also assessed cytotoxicty of the conjugate using L929 fibroblast cells and quantified by MTT assay. (c) 2011 Elsevier Inc. All rights reserved.
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    Enhanced Drug Loading on Magnetic Nanoparticles by Layer-by-Layer Assembly Using Drug Conjugates: Blood Compatibility Evaluation and Targeted Drug Delivery in Cancer Cells
    (LANGMUIR, 2011)
    Drug targeting using magnetic nanoparticles (MNPs) under the action of an external magnetic field constitutes an important mode of drug delivery. Low cargo capacity, particularly in hydrophobic drugs, is one limitation shown by MNPs. This article describes a simple strategy to enhance the drug-loading capacity of MNPs. The approach was to use polymer-drug conjugates to modify MNPs by layer-by-layer assembly (LbL). Curcumin (CUR) has shown remarkably high cytotoxicity toward various cancer cell lines. However, the drug shows low anticancer activity in vivo because of its reduced systemic bioavailability acquired from its poor aqueous solubility and instability. To address this issue, we synthesized cationic and anionic CUR conjugates by anchoring CUR onto poly(vinylpyrroidone) (PVP-Cur) and onto hyaluronic acid (HA-Cur). We used these oppositely charged conjugates to modify MNPs by layer-by-layer (LbL) assembly. Six double layers of curcumin conjugates were constructed on positively charged amino-terminated magnetic nanoparticles, TMSPEDA@MNPs. Finally, HA was coated onto the outer surface to form HA (HA-Cur/PVP-Cur)(6)@MNPs. Cellular viability studies showed the dose-dependent antiproliferative effect of HA (HA-Cur/PVP-Cur)(6)@MNPs in two cancer cell lines (glioma cells and Caco-2 cells). HA (HA-Cur/PVP-Cur)(6)@MNPs exhibited more cytotoxicity than did free curcumin, which was attributed to the enhanced solubility along with better absorption via hyaluronic acid receptor-mediated endocytosis. Flow cytometry showed enhanced intake of the modified MNPs by cells. Confocal microscope images also confirmed the uptake of HA (HA-Cur/PVP-Cur)(6)@MNPs with greater efficacy. Thus, the strategy that we adopted here appears to have substantial potential in carrying enhanced payloads of hydrophobic drugs to specified targets.
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    Fluorescent molecularly imprinted polymer film binds glucose with a concomitant changes in fluorescence
    (BIOSENSORS & BIOELECTRONICS, 2010)
    A fluorescent molecularly imprinted polymeric formulation capable of picking up glucose from aqueous media is reported. The fluorescence intensity of the polymer film was found to reduce proportionally with the concentration of glucose facilitating its use as a glucose sensing element. We used commercially available tear fluid to demonstrate the ability of the film to recognize glucose among other sugar molecules. Fluorescence was measured after equilibrating the film in tear fluid in the presence of a mixture of different sugars. We observed a reduction in fluorescence intensity due to the nonspecific binding of the sugars. The intensity remains the same even if we added additional quantities of the sugars. Interestingly, the fluorescence intensity of the film was found to decrease proportionally when varied concentrations of glucose was added indicating the ability of the film to recognize and bind glucose from a mixture of other sugars. Detectable changes in fluorescence intensity were observed with a concentration of 10 mu g/mL of glucose. The results show that the polymer film could be used for detecting glucose in aqueous fluids such as tear. (C) 2010 Elsevier B.V. All rights reserved.
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    Gold nanoparticles generated and stabilized by water soluble curcumin-polymer conjugate: Blood compatibility evaluation and targeted drug delivery onto cancer cells
    (JOURNAL OF COLLOID AND INTERFACE SCIENCE, 2012)
    Curcumin (Cur) shows low anticancer activity in vivo due to its reduced systemic bioavailability stemmed from its poor aqueous solubility and instability. Suitably functionalized nanocarriers designed to empty the drug specifically at tumor sites can potentially enhance the antitumor activity of Cur. We devised a simple method for the fabrication of water soluble Cur conjugated gold nanoparticles to target various cancer cell lines. Cur was conjugated to hyaluronic acid (HA) to get a water soluble conjugate (HA-Cur). We generated gold nanoparticles (AuNPs) by reducing chloroauric acid using HA-Cur, which played the dual role of a reducing and stabilizing agent and subsequently anchored folate conjugated PEG. These entities were probed using different analytical techniques, assayed the blood compatibility and cytotoxicity. Their interaction with cancer cell lines (HeLa cells, glyoma cells and Caco 2 cells) was followed by flow cytometry and confocal microscopy. Blood-materials interactions studies showed that the nanoparticles are highly hemocompatible. Flow cytometry and confocal microscopy results showed significant cellular uptake and internalization of the particles by cells. HA-Cur@AuNPs exhibited more cytotoxicity comparing to free Cur. The strategy, we adopted here, resulted the formation blood compatible Cur conjugated AuNPs with enhanced targeting and improved efficacy. (C) 2011 Elsevier Inc. All rights reserved.
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    Hollow microcapsules built by layer by layer assembly for the encapsulation and sustained release of curcumin
    (COLLOIDS AND SURFACES B-BIOINTERFACES, 2011)
    Hollow microcapsules fabricated by layer-by-layer assembly (LbL) using oppositely charged polyelectrolytes have figured in studies towards the design of novel drug delivery systems. The possibility of loading a fair amount of active component of poor aqueous solubility is one of the encouraging factors on the wide spread interest of this emerging technology. Curcumin has potent anti-cancer properties. Clinical application of this efficacious agent in cancer and other diseases has been limited due to poor aqueous solubility and consequently minimal systemic bioavailability. LbL constructed polyelectrolyte microcapsules based drug delivery systems have the potential for dispersing hydrophobic agent like curcumin in aqueous media. Here we report the preparation of LbL assembled microcapsules composed of poly(sodium 4-styrene sulfonic acid) and poly(ethylene imine) one after another. The microcapsules were characterized using various analytical techniques. Curcumin was encapsulated in these microcapsules and the efficacy of the released curcumin was studied using L929 cells. (C) 2010 Elsevier B.V. All rights reserved.
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    Layer-by-Layer modification of Poly (methyl methacrylate) intra ocular lens: Drug delivery applications
    (PHARMACEUTICAL DEVELOPMENT AND TECHNOLOGY, 2010)
    Even though infection followed by Intra ocular lens (IOL) implantation is a rare complication, therapeutic options are limited and it affects the vision seriously. Interestingly, IOL itself acts as substrate for the adhesion and proliferation of bacteria. An approach to facilitate antibacterial drug adsorption onto the surface of IOL through the modification of IOL surface using the concept of Layer-by-Layer (LbL) formation without sacrificing the vital optical features of the IOLs is presented here. Polyelectroylte multilayers incorporating ampicillin was fabricated on the IOLs using LbL deposition of Poly (sodium 4-styrenesulfonate) (PSS) and Poly (ethylenimine) (PEI). Altogether six layers were formed. The layer formation enabled the IOL to adsorb the drug and modulated the release in a sustained fashion. It appears that using this strategy, IOLs could be modified using a variety of degradable or non-degradable materials to precisely control the delivery of active components to protect eye and the device.
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    Synthesis and Characterization of a Cytotoxic Cationic Polyvinylpyrrolidone-Curcumin Conjugate
    (JOURNAL OF PHARMACEUTICAL SCIENCES, 2011)
    Curcumin has been studied as a potential drug for many diseases including cancer. One of the serious limitations projected on curcumin is its poor water solubility and the substantially low bioavailability. With a view to enhance the aqueous solubility of curcumin, we synthesized polyvinylpyrrolidone curcumin conjugates. Polyvinylpyrrolidone was used for the conjugation considering its long history of safe usage as a biomaterial for various medical applications. The drug conjugates self-assembled in aqueous solution to form nanosized micellar aggregates. The formation of micellae stabilized curcumin against hydrolytic degradation. Another interesting feature of the conjugate was its cationic nature. The net zeta potential in the pH range from 3 to 7.4 was +25 to +20 mV, reflecting the potential stability of the conjugate micellae at physiological pH. We quantified cytotoxic potential of the conjugate by the MTT assay, using L929 fibroblast cells. The results showed that the conjugate had higher cytotoxicity than that of the free curcumin. It is expected that the relative enhanced cytotoxicities are the result of enhanced aqueous solubility and polymer-mediated drug internalization. The conjugate has the potential to circumvent limitations of curcumin and thereby to extrapolate further its applications as an effective anticancer drug. (C) 2010 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 100:504-511, 2011