Browsing by Author "Priya, SS"

Now showing 1 - 3 of 3
  • Item
    Disulphide cross linked pullulan based cationic polymer for improved gene delivery and efflux pump inhibition
    (COLLOIDS AND SURFACES B-BIOINTERFACES, 2016) Priya, SS; Rekha, MR
    Multidrug resistance is a hurdle to successful cancer chemotherapy. Over expression of P-glycoprotein (P-gp) is a prime contributing factor for drug resistance. In this study, a disulphide cross-linked pullulan-based cationic polymer (PPSS) was synthesized to act simultaneously as gene delivery vehicle and efflux pump inhibitor. The PPSS nanoplexes were of size <200 nm with the zeta potential of +15 to +20 mV. The cytotoxicity studies using C6 and L929 cells showed that PPSS polymers are non-toxic even at high polymer concentrations. The PPSS/pDNA nanoplex showed superior uptake in confocal microscopy with 97% uptake by flow cytometry. The efficacy of efflux pump inhibition by the PPSS nanoplex was established by the enhanced intracellular retention of DOX. The enhanced cell death by p53/PPSS/DOX nanoplexes was attributed to the synergistic effect of P-gp inhibition and p53 transfection efficiency. Therefore, this multifunctional polymeric system may have significant promise for therapeutic application against cancer drug resistance. (C) 2016 Elsevier B.V. All rights reserved.
  • Item
    Methotrexate anchored carbon dots as theranostic probes: digitonin conjugation enhances cellular uptake and cytotoxicity
    (RSC Advances, 2016-06) Krishna, AS; Radhakumary, C; Priya, SS; Ramesan, RM; Sreenivasan, K
    In recent years carbon dots (CDs) have been drawing increasing attention in the area of nano medicine. Their indubitable roles in cellular imaging, drug delivery and diagnosis are widely acknowledged. Digitonin (DG) has traditionally been known as a cell membrane permeabilizing agent. Based on this fact, we modified CDs with DG (CDDG) and further conjugated them with methotrexate (MX). This probe, CDDG conjugated MX (CDMX) was subjected to physico chemical characterization, cytotoxic evaluation via MTT assay and cellular uptake studies using confocal laser microscopy. The drug release study implied that at physiological pH, release is less reflecting maximum drug retention in the probe during circulation. The results which emerged have shown that DG is impacted in enhancing cellular uptake and cytotoxic potential of the drug carriers. The study indicates that theranostic probes with improved features can be generated from CDs by a judicious modification
  • Item
    Pullulan-protamine as efficient haemocompatible gene delivery vector: Synthesis and in vitro characterization
    (Carbohydrate Polymers., 2014-02) Priya, SS; Rekha, MR; Sharma, CP
    Biodegradable non-viral vectors with good transfection efficiency is essential for successful gene delivery. The purpose of this study was to design a non-viral vector by conjugating protamine to pullulan and elucidate the potential use of pullulan protamine conjugate (PPA) as an effective, non toxic and haemocompatible gene delivery system. The particle size and surface charge were measured using Nanosizer. Derivatization was confirmed by NMR, FTIR and DSC analyses. Acid base titration revealed the buffering behaviour of the conjugate. The protection of DNA from nuclease enzyme and interaction of plasma components on the stability of nanoplexes were also analysed. The uptake studies confirmed the plasmid delivery into the nucleus and the inhibitor studies determined the uptake mechanism. Transfection experiments revealed the capability of PPA to cellular uptake in C6 cells and facilitate high gene expression. Thus, PPA proves to be a promising non-viral vector.