Vijaykumar Sutariya

Brain-targeted delivery of paclitaxel using glutathione-coated nanoparticles for brain cancers

Paclitaxel is not effective for treatment of brain cancers because it cannot cross the blood–brain barrier (BBB) due to efflux by P-glycoprotein (P-gp). In this work, glutathione-coated poly-(lactide-co-glycolide) (PLGA) nanoparticles (NPs) of paclitaxel were developed for brain targeting for treatment of brain cancers. P-gp ATPase assay was used to evaluate the NP as potential substrates. The NP showed a particle size suitable for BBB permeation (particle size around 200 nm) and higher cellular uptake of the NP was demonstrated in RG2 cells. The P-gp ATPase assay suggested that the NP were not substrate for P-gp and would not be effluxed by P-gp present in the BBB. The in vitro release profile of the NP exhibited no initial burst release and showed sustained drug release. The proposed coated NP showed significantly higher cytotoxicity in RG2 cells compared with uncoated NP (p ≤ 0.05). Tubulin immunofluorescent study showed higher cell death by the NP due to increased microtubule stabilization. In vivo brain uptake study in mice showed higher brain uptake of the NP containing coumarin-6 compared with solution. The proposed brain-targeted NP delivery of paclitaxel could be an effective treatment for the brain cancers.

Brain-targeted delivery of docetaxel by glutathione-coated nanoparticles for brain cancer.

Gliomas are some of the most aggressive types of cancers but the blood–brain barrier acts as an obstacle to therapeutic intervention in brain-related diseases. The blood–brain barrier blocks the permeation of potentially toxic compounds into neural tissue through the interactions of brain endothelial cells with glial cells (astrocytes and pericytes) which induce the formation of tight junctions in endothelial cells lining the blood capillaries. In the present study, we characterize a glutathione-coated docetaxel-loaded PEG-PLGA nanoparticle, show its in vitro drug release data along with cytotoxicity data in C6 and RG2 cells, and investigate its trans-blood–brain barrier permeation through the establishment of a Transwell cellular co-culture. We show that the docetaxel-loaded nanoparticle’s size enables its trans-blood–brain barrier permeation; the nanoparticle exhibits a steady, sustained release of docetaxel; the drug is able to induce cell death in glioma models; and the glutathione-coated nanoparticle is able to permeate through the Transwell in vitro blood–brain barrier model.

Artificial Neural Network in Drug Delivery and Pharmaceutical Research

Artificial neural networks (ANNs) technology models the pattern recognition capabilities of the neural networks of the brain. Similarly to a single neuron in the brain, artificial neuron unit receives inputs from many external sources, processes them, and makes decisions. Interestingly, ANN simulates the biological nervous system and draws on analogues of adaptive biological neurons. ANNs do not require rigidly structured experimental designs and can map functions using historical or incomplete data, which makes them a powerful tool for simulation of various non-linear systems.ANNs have many applications in various fields, including engineering, psychology, medicinal chemistry and pharmaceutical research. Because of their capacity for making predictions, pattern recognition, and modeling, ANNs have been very useful in many aspects of pharmaceutical research including modeling of the brain neural network, analytical data analysis, drug modeling, protein structure and function, dosage optimization and manufacturing, pharmacokinetics and pharmacodynamics modeling, and in vitro in vivo correlations. This review discusses the applications of ANNs in drug delivery and pharmacological research.

Brain-targeted delivery of doxorubicin using glutathione-coated nanoparticles for brain cancers.

Abstract Objectives: To prepare and characterize in vitro a novel brain-targeted delivery of doxorubicin using glutathione-coated nanoparticles (NPs) for the treatment of brain cancer. Methods: Doxorubicin-loaded NPs were prepared by the nanoprecipitation method using PLGA-COOH (dl-lactide-co-glycolide). The NPs were coated with a glutathione-PEG conjugate (PEG-GSH) in order to target delivery to the brain. The NPs were characterized via in vitro studies to determine particle size, drug release, cellular uptake, immunofluorescence study, cytotoxic assay, and in vitro blood–brain barrier (BBB) assay. Results: The NPs showed a particle size suitable for BBB permeation (particle size around 200 nm). The in vitro release profile of the NPs exhibited no initial burst release and showed sustained drug release for up to 96 h. The immunofluorescence study showed the glutathione coating does not interfere with the drug release. Furthermore, in vitro BBB Transwell™ study showed significantly higher permeation of the doxorubicin-loaded NPs compared with the free doxorubicin solution through the coculture of rat brain endothelial (RBE4) and C6 astrocytoma cells (p < 0.05). Conclusions: We conclude that the initial in vitro characterization of the NPs demonstrates potential in delivering doxorubicin to cancer cells with possible future application in targeting brain cancers in vivo.

Triamcinolone acetonide nanoparticles incorporated in thermoreversible gels for age-related macular degeneration

Abstract Age-related macular degeneration (AMD) is one of the leading causes of blindness in the US affecting millions yearly. It is characterized by intraocular neovascularization, inflammation and retinal damage which can be ameliorated through intraocular injections of glucocorticoids. However, the complications that arise from repetitive injections as well as the difficulty posed by targeting the posterior segment of the eye make this interesting territory for the development of novel drug delivery systems (DDS). In the present study, we described the development of a DDS composed of triamcinolone acetonide-encapsulated PEGylated PLGA nanoparticles (NP) incorporated into PLGA–PEG–PLGA thermoreversible gel and its use against VEGF expression characteristic of AMD. We found that the NP with mean size of 208 ± 1.0 nm showed uniform size distribution and exhibited sustained release of the drug. We also demonstrated that the polymer can be injected as a solution and transition to a gel phase based on the biological temperature of the eye. Additionally, the proposed DDS was non-cytotoxic to ARPE-19 cells and significantly reduced VEGF expression by 43.5 ± 3.9% as compared to a 1.53 ± 11.1% reduction with triamcinolone. These results suggest the proposed DDS will contribute to the development of novel therapeutic strategies for AMD.

Preparation and characterization of methylene blue nanoparticles for Alzheimer's disease and other tauopathies.

Methylene blue (MB) has been shown to slow down the progression of the Alzheimers disease (AD) and other tauopathies; however distribution of MB into the brain is limited due its high hydrophilicity. In this study, we aimed to prepare novel hydrophobic glutathione coated PLGA nanoparticles to improve bioavailability of MB in the brain. Glutathione coated poly-(lactide-co-glycolide) (PLGA-b-PEG) nanoparticles (NPs) were prepared and tested in two different cell culture models of AD expressing microtubule associated protein tau (tau). The NPs showed a particle size averaging 136.5±4.4nm, which is suitable for the blood brain barrier (BBB) permeation. The in vitro release profile of the NPs exhibited no initial burst release and showed sustained drug release for up to 144 hours. Interestingly, treatment of newly formulated MB-NPs showed a potent reduction in both endogenous and over expressed tau protein levels in human neuroblastoma SHSY-5Y cells expressing endogenous tau and transfected HeLa cells over-expressing tau protein, respectively. Furthermore, in vitro BBB Transwell™ study showed significantly higher permeation of MB-NP compared to the MB solution through the co culture of rat brain endothelial 4 (RBE4) and C6 astrocytoma cells (p<0.05). The proposed MB loaded nanoparticles could provide a more effective treatment option for AD and many other related disorders.

Nanoparticulate Transscleral Ocular Drug Delivery

Ocular drug delivery is one of the most challenging areas of drug delivery due to the unique mostly avascular nature of the major eye structures and presence of two blood barriers. Effectiveness of a more conventional systemic delivery falls short due to low drug levels in the eye tissue. Periocular approaches require penetration of fibrous sclera and present their own limitations. Utilization of nanotechnology presents new avenue of drug system development with potential to penetrate protective barriers and sustain ample tissue saturation. More specifically, transscleral delivery permits a range of applications in targeted delivery, gene, stem cell, protein and peptides, oligonucleotide, and ribozyme therapies. The exciting range of current applications is expounded in this review.

Micronisation of simvastatin by the supercritical antisolvent technique: in vitro–in vivo evaluation

Abstract Micronisation of simvastatin dissolved in acetone, dimethyl sulfoxide and ethanol with supercritical carbon dioxide as antisolvent was successfully performed using a supercritical antisolvent technique. The effect of a few process parameters such as precipitation temperature, the pressure and solute concentration in the liquid solution has been studied to evaluate their influence on morphology and size of particles. The micronised simvastatin were evaluated for drug content, particle size analysis and in vitro dissolution profiles. Fourier transform infrared spectroscopy, differential scanning calorimetry and PXRD patterns was used to study the possible changes after micronisation of simvastatin. The dissolution rate was increased after micronised compared with pure simvastatin in distilled water, pH 1.2 buffer and pH 7.0 buffer. In vivo performance of the optimised formulation was evaluated in rats using pharmacodynamic marker parameters like serum total cholesterol (CH) and triglycerides (TG) for 21 days. Pharmacodynamic studies of micronised simvastatin revealed improved reduction in CH and TG values as compared with pure simvastatin indicating improved bioavailability. In vivo pharmacokinetics in rats showed an increase in bioavailability of micronised simvastatin (3.14 times) compared with plain simvastatin.

Preparation and Characterization of Microemulsion of Cilostazol for Enhancement of Oral Bioavailability

Cilostazol is a promising drug for antiplatelet combination therapy that is very important for treatment for various cardiovascular disorders. However, oral delivery of this drug is greatly impeded by the poor solubility in aqueous solutions. The aim of this study was to develop microemulsion (ME) delivery system capable of improving the drug bioavailability. In this study, Capmul MCM C8 (glycerol monocaprylate) based MEs containing Tween 20(polysorbate 20) and/or Labrafil M 1944(poly oxyglycerides) as surfactant(S) and Transcutol P(diethyl glycol monoethyl ether) as cosurfactant(CoS) were studied as potential delivery systems of cilostazol. A number of such systems were prepared containing different S:CoS ratios(1:1, 2:1 and 3:1) based on phase diagrams. Loading of cilostazol was selected as per solubilization capacity and was characterized for pH, viscosity, conductivity, particle size, zeta potential and % transmittance. The MEs systems were further investigated for chemical stability, diffusion and bioavailability. Cilostazol displayed high solubility in microemulsions with particle size up to 70 nm. It was also stable at ambient temperature up to 6 months without significant change in particle size, zeta potential, and % transmittance. Dilution up to 100 fold with aqueous medium observed a visible cloudiness having a particle size up to 104 nm. The in vitro release, and ex vivo intraduodenal diffusion, and in vivo study indicated the capacity of developed ME to improve the bioavailability (1.43 fold) via oral route administration when compared with commercially available tablets (Pletoz-50).

Blood-Brain Barrier Permeation of Glutathione-Coated Nanoparticle

Brain-related diseases are some of the most aggressive, but are also some of the hardest to treat. One of the main obstacles in attempting to treat brain-related diseases is surmounting the blood-brain barrier, a physiological barrier that separates neural tissue from the blood through the interactions of glial cells and endothelial cells. The present study describes the establishment of an in vitro blood-brain barrier model through the co-culture of rat brain endothelial (RBE4) and astrocytic (C6) cells on Transwell™ permeable support inserts. Coating organic, drug-encapsulating nanoparticles with glutathione helps the nanoparticles cross the in vitro blood-brain barrier model better than identical concentrations of uncoated nanoparticles and the free drug solution. This provides the basis for conjugating nanoparticles or other drug vectors with glutathione in clinical settings to enhance the trans-blood-brain barrier permeation of brain-targeted therapies. The implementation of this method in therapies has the potential to influence therapies of brain-related disorders by specifically targeting neural tissue with therapeutic compounds.