Development and Antibacterial Investigation of Linezolid-Loaded SPIONs and HPLC Method Development for Quantitative Analysis of Linezolid.

BACKGROUND: Linezolid (LNZ) is extremely prone to resistance. The development of resistance to LNZ should be taken into consideration when selecting this drug as a therapeutic option. It is well established that reactive oxygen species (ROS) generated by iron oxide nanoparticles (MNPs) could kill the infecting bacteria. So, we hypothesized the synergistic antibacterial effect of iron oxide nanoparticles and LNZ. OBJECTIVE: To study the release and antibacterial effects of LNZ-loaded superparamagnetic iron oxide nanoparticles (SPIONs) on Staphylococcus aureus and Streptococcus pneumoniae. METHOD: Ferrofluid containing SPIONs was synthesized via chemical co-precipitation method and stabilized by sodium lauryl sulphate (SLS). SPIONs were then loaded with LNZ and characterized for particle size, FT-IR, XRD, and entrapment efficiency. Further antibacterial activity of SPIONs and LNZ-loaded SPIONs was investigated. For the in vitro release findings, HPLC analytical method development and validation were performed. RESULTS: Isolation of LNZ was accomplished on a C-18 column with methanol-TBHS (tetra butyl ammonium hydrogen sulphate, 50:50, v/v). The eluate was monitored at 247 nm with a retention time of 4.175 min. The MNP's DLS measurement revealed monodispersed particles with an average size of 16.81 ± 1.07 nm and PDI 0.176 ± 0.012. In optimized formulation, 25 ± 1.75% (w/w) of the drug was found to be entrapped. XRD revealed uniform coating of oleic acid covering the entire magnetic particles' surface with no change in its crystallinity. An effective antimicrobial activity was observed at the lowered dose of drug. CONCLUSIONS: A robust HPLC method was developed to quantify the LNZ in MNPs, and outcomes showed that the reduced dose of LNZ incorporated in SPIONs was able to show similar activity as the marketed product. HIGHLIGHTS: Successfully reduction of the dose of LNZ was established with the aid of biocompatible MNPs to attain the equivalent antibacterial activity.

Doxorubicin loaded carboxymethyl Assam bora rice starch coated superparamagnetic iron oxide nanoparticles as potential antitumor cargo.

In recent years, polysaccharide-decorated superparamagnetic iron oxide nanoparticles (SPIONs) have gained attention in the field of "nanotheranostics" with integrated diagnostic and therapeutic functions. Carboxymethyl Assam bora rice starch-stabilized SPIONs (CM-ABRS SPIONs), synthesized by co-precipitation method, has already shown exciting potential towards magnetic drug targeting potential. After establishing it as a promisable targeting carrier, the present study is focused on the next step i.e. to evaluate its In vitro anti-tumor potential by loading anticancer drug "Doxorubicin hydrochloride (DOX)" onto CM-ABRS SPIONs. DOX-loaded CM-ABRS SPIONs were physico-chemically characterized by DLS, zeta-potential, TEM, FT-IR, XRD, and VSM analysis. Spectroflourimetric analysis confirmed the maximum loading of DOX up to 6% (w/w) onto CM-ABRS SPIONs via electrostatic interactions. Further, molecular level drug performance was investigated by docking study against receptors (HER-2 and Folate receptor-α) over expressed in cancer cells and MTT assay (in MCF-7 and HeLa cell line), which conferred promisable results of DOX-CM-ABRS SPIONs as compared to standard DOX solution.

Carboxymethyl Assam Bora rice starch coated SPIONs: Synthesis, characterization and in vitro localization in a micro capillary for simulating a targeted drug delivery system.

Carboxymethyl Assam Bora rice starch coated superparamagnetic iron oxide nanoparticles (CM-ABRS SPIONs) were chemically synthesized by co-precipitation method and particle size reduction was controlled by high energy homogenization process. Effects of various process variables (polymer concentration, homogenization speed and cycles) were optimized on the basis of average particle size (Z-average) and polydispersity index (PDI) of CM-ABRS SPIONs. The optimized CM-ABRS SPIONs were characterized for their particle size, surface morphology, electrokinetic potential, chemical interactions, crystallinity, magnetic properties, and targeting potential in presence of external magnetic field. In vitro localization of CM-ABRS SPIONs in a suspension of FITC (Fluorescein isothiocyanate) labeled RBCs (Red blood cells; hematocrit value; 45% (v/v)) was conducted inside a square glass capillary (500 × 500 µm2 cross section) in the presence of an externally applied magnetic field (Ms = 150 mT), simulating the case of magnetic drug targeting (MDT) approach. The aggregation dynamics of CM-ABRS SPIONs inside a micro capillary was observed with respect to time (t = 0 to 600 s), which shows proportionality to time of exposure to the externally applied magnetic field. This in vitro study acts as an important platform for design and optimization of active targeted drug delivery system.

Synthesis and characterization of novel carboxymethyl Assam Bora rice starch for the controlled release of cationic anticancer drug based on electrostatic interactions.

Carboxymethyl Assam Bora rice starch (CM-ABRS) was chemically synthesized in non-aqueous medium with the optimum degree of substitution (DS) of 1.23, and physicochemically characterized by FT-IR, DSC, XRD, and SEM analysis. Comparative evaluation of CM-ABRS with native starch (ABRS) for powder flow characteristics, swelling index, apparent solubility, rheological properties, textural properties, and mucoadhesive studies were carried out. The aim of the current work was to investigate the potential of CM-ABRS as a novel carrier for the water-soluble chemotherapeutic, doxorubicin hydrochloride (DOX). Formation of drug/polymer complex (DOX-CM-ABRS) via electrostatic interaction has been evaluated for the controlled release of DOX in three different pH media (phosphate-buffered saline (PBS), pH 7.4, 6.8, and 5.5). In vitro drug release studies illustrated faster release of drug in PBS at pH 5.5 as compared to pH 6.8 and pH 7.4, respectively, indicating the importance of pH-sensitive drug release from the DOX-CM-ABRS complex in malignant tissues.

Enhanced anti-tumor efficacy of paclitaxel with PEGylated lipidic nanocapsules in presence of curcumin and poloxamer: In vitro and in vivo studies.

Cancer chemotherapeutic drug containing PEGylated lipidic nanocapsules (D-LNCs) were formulated by the controlled addition of organic phase (combined solution of paclitaxel and curcumin in a mixture of oleic acid and MPEG2000-DSPE (90:2.5 molar ratio) in acetone) to the aqueous phase (consist of Poloxamer 407 as emulsifying agents and glycerol as a co-solvent) at a temperature of 55-60°C followed by evaporation of organic solvent. The obtained pre-colloidal dispersion of D-LNCs was processed through high pressure homogenization to get more uniformly and nano-sized particles. Effect of concentration of emulsifying agent and process variables of high pressure homogenization (pressure and number of cycles) on average particle size and entrapment efficiency was further investigated by constructing Box-Behnken experimental design to achieve the optimum manufacturing process. D-LNCs were characterized by dynamic light scattering, scanning and transmission electron microscopy, Fourier transform infrared spectroscopy, and differential scanning calorimetry. In vitro release studies showed a sustained release pattern of drug from the PEGylated D-LNCs, whereas in vivo pharmacokinetic studies after a single-dose intravenous (i.v.) administration of paclitaxel (15mg/kg) in Ehrlich ascites tumor (EAT)-bearing female Swiss albino mice showed a prolonged circulation time and slower elimination of paclitaxel from D-LNCs as compared with marketed formulation (Paclitec®). From the plasma concentration vs. time profile, i.v. bioavailability (AUC0-∞) of paclitaxel from D-LNCs was found to be increased approximately 2.91-fold (P<0.001) as compared to Paclitec®. In vitro cell viability assay against MCF-7 and MCF-7/ADR cell lines, in vivo biodistribution studies and tumor inhibition study in EAT-bearing mice, all together prove its significantly improved potency towards cancer therapy.

Experimental investigation and oral bioavailability enhancement of nano-sized curcumin by using supercritical anti-solvent process.

The biomedical applications of curcumin (CUR) are limited due to its poor oral bioavailability. In this work, CUR nanoparticles were successfully prepared by combining the supercritical anti-solvent (SAS) process with Tween 80 as a solubilizing agent and permeation enhancer. Different processing parameters that can govern the mean particle size and size distribution of nanoparticles were well investigated by manipulating the types of solvents, mixing vessel pressure, mixing vessel temperature, CO2 flow rate, solution flow rate and solution concentration. Solid state characterization was done by Fourier Transform infrared spectroscopy, differential scanning calorimetry, dynamic light scattering, scanning electron microscopy, and powder X-ray diffraction study. Solubility and dissolution profile of SAS-processed CUR were found to be significantly increased in comparison with native CUR. Further, a validated ultra-performance liquid chromatographic method with quadrupole-time of flight-mass spectrometry was developed to investigate the pharmacokinetic parameters after a single oral dose (100mg/kg) administration of CUR (before/after SAS-processed) in male Wistar rats. From the plasma concentration vs. time profile graph, oral bioavailability of SAS-processed CUR was found to be increased approximately 11.6-fold (p<0.001) as compared to native CUR.

Synthesis and in vitro localization study of curcumin-loaded SPIONs in a micro capillary for simulating a targeted drug delivery system.

Nano-sized curcumin-loaded super-paramagnetic iron oxide nanoparticles (CUR-OA-SPIONs) were synthesized chemically by co-precipitation method using oleic acid as a stabilizer and Myrj 52 as a surfactant. The synthesized nanoparticles were characterized for their shape, size, surface morphology, electrokinetic potential, magnetic properties, crystalinity, chemical interactions and thermal transitions. The synthesized CUR-OA-SPIONs were spherical, mono-dispersed, physically stable and super-paramagnetic in nature. In vitro localization study and aggregation dynamics of CUR-OA-SPIONs were studied with a flow of blood inside a square glass capillary (500×500 µm(2) cross section) in the presence of an externally applied magnetic field (Ms=1200 mT). This research which is first of its kind showed the fluorescent imaging of CUR-OA-SPIONs with respect to time to understand the aggregation dynamics of magnetic nanoparticles in a micro capillary simulating the case of targeted drug delivery system. The size of the aggregation increases with respect to time (t=0(+)s to t=500 s), while no significant change in the size of the aggregate was observed after time t=500 s.