Biswajit Mukherjee

Lipid peroxidation, glutathione levels and changes in glutathione-related enzyme activities in streptozotocin-induced diabetic rats

Levels of lipid peroxidation in liver, kidney, brain and blood, liver glutathione (GSH) and several enzymes in liver tissue associated with antioxidant defence mechanism, namely Catalase (EC: 1.11.1.6), GSH reductase (EC:1.6.4.2) and GSH‐s‐transferase (EC: 2.5.1.18), were investigated in streptozotocin‐induced diabetic rats. The single intraperitoneal injection of streptozotocin (65 mg/kg) caused a four‐, eight‐ and seven‐fold increase in lipid peroxidation in brain, liver and kidney, respectively. A decline in GSH levels both in blood (two–fold) and liver (16%) compared with normal counterparts was also observed. A marginal increase in catalase activity, a 20% decrease in GSH reductase and an increase of GSH‐5‐transferase activity was also found in this experimental diabetic condition. These results suggest experimental diabetes, induced by streptozotocin, can produce biochemical changes not only in pancreas but also in liver, kidney and brain tissue.

Preparation, characterization and in-vitro evaluation of sustained release protein-loaded nanoparticles based on biodegradable polymers.

Controlled drug delivery technology of proteins/peptides from biodegradable nanoparticles has emerged as one of the eminent areas to overcome formulation associated problems of the macromolecules. The purpose of the present investigation was to develop protein-loaded nanoparticles using biodegradable polymer poly l-lactide-co-glycolidic acid (PLGA) with bovine serum albumin (BSA) as a model protein. Despite many studies available with PLGA-based protein-loaded nanoparticles, production know-how, process parameters, protein loading, duration of protein release, narrowing polydispersity of particles have not been investigated enough to scale up manufacturing of protein-loaded nanoparticles in formulations. Different process parameters such as protein/polymer ratio, homogenizing speed during emulsifications, particle surface morphology and surface charges, particle size analysis and in-vitro protein release were investigated. The in-vitro protein release study suggests that release profile of BSA from nanoparticles could be modulated by changing protein-polymer ratios and/or by varying homogenizing speed during multiple-emulsion preparation technique. The formulation prepared with protein-polymer ratio of 1:60 at 17,500 rpm gave maximum protein-loading, minimum polydispersion with maximally sustained protein release pattern, among the prepared formulations. Decreased (10,000 rpm) or enhanced (24,000 rpm) homogenizing speeds resulted in increased polydispersion with larger particles having no better protein-loading and -release profiles in the present study.

Development of biodegradable polymer based tamoxifen citrate loaded nanoparticles and effect of some manufacturing process parameters on them: a physicochemical and in-vitro evaluation.

The aim of the present study was to develop nanoparticles of tamoxifen citrate, a non-steroidal antiestrogenic drug used for the treatment of breast cancer. Biodegradable poly (D, L- lactide-co-glycolide)-85:15 (PLGA) was used to develop nanoparticles of tamoxifen citrate by multiple emulsification (w/o/w) and solvent evaporation technique. Drug-polymer ratio, polyvinyl alcohol concentrations, and homogenizing speeds were varied at different stages of preparation to optimize the desired size and release profile of drug. The characterization of particle morphology and shape was performed by field emission scanning electron microscope (FE-SEM) and particle size distribution patterns were studied by direct light scattering method using zeta sizer. In vitro drug release study showed that release profile of tamoxifen from biodegradable nanoparticles varied due to the change in speed of centrifugation for separation. Drug loading efficiency varied from 18.60% to 71.98%. The FE-SEM study showed that biodegradable nanoparticles were smooth and spherical in shape. The stability studies of tamoxifen citrate in the experimental nanoparticles showed the structural integrity of tamoxifen citrate in PLGA nanoparticles up to 60°C in the tested temperatures. Nanoparticles containing tamoxifen citrate could be useful for the controlled delivery of the drug for a prolonged period.

Poly-lactide-co-glycolide nanoparticles containing voriconazole for pulmonary delivery: in vitro and in vivo study

UNLABELLED Poly-lactide-co-glycolide nanoparticles (207-605 nm) containing voriconazole (VNPs) were developed using a multiple-emulsification technique and were also made porous during preparation in presence of an effervescent mixture for improved pulmonary delivery. Pulmonary deposition of the particles was studied using a customized inhalation chamber. VNPs had a maximum of 30% (w/w) drug loading and a zeta potential (ZP) value around -20 mV. In the initial 2 hours, 20% of the drug was released from VNPs, followed by sustained release for 15 days. Porous particles had a lower mass median aerodynamic diameter (MMAD) than nonporous particles. Porous particles produced the highest initial drug deposition (~120 μg/g of tissue). The drug was detectable in lungs until 7 days and 5 days after administration, for porous and nonporous particles, respectively. VNPs with improved drug loading were successfully delivered to murine lungs. Porous nanoparticles with lower MMADs showed better pulmonary deposition and sustained presence in lungs. FROM THE CLINICAL EDITOR In this paper, voriconazole-containing porous nanoparticles were studied for inhalational delivery to lung infections in a murine model, demonstrating prolonged half-life and improved pulmonary deposition.

Doxorubicin-loaded phosphatidylethanolamine-conjugated nanoliposomes: in vitro characterization and their accumulation in liver, kidneys, and lungs in rats

Introduction Phosphatidylethanolamine (PE)-conjugated nanoliposomes were developed, characterized, and investigated for their accumulation in liver, kidneys, and lungs in rats. Methods Drug-excipient interaction was studied using Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), surface morphology by field emission scanning electron microscopy, elemental analysis by energy dispersive X-ray (EDX) analysis, zeta potential and size distribution using a Zetasizer and particle size analyzer, and in vitro drug release by dialysis membrane. In vivo accumulation of liposomes in tissues was also studied. Results No chemical reaction was observed between drug and excipients. EDX study confirmed PE-conjugation in liposomes. Doxorubicin-loaded liposomes (DOX-L) and PE-conjugated doxorubicin-loaded liposomes (DOX-PEL) were of smooth surface and homogenously distributed in nanosize range (32–37 nm) with a negative surface charge. Loading efficiencies were 49.25% ± 1.05% and 52.98% ± 3.22% respectively, for DOX-L and DOX-PEL. In vitro drug release study showed 69.91% ± 1.05% and 77.07% ± 1.02% doxorubicin released, from DOX-L and DOX-PEL, respectively, in nine hours. Fluorescence microscopic study showed that liposomes were well distributed in liver, lungs, and kidneys. Conclusion Data suggests that PE-conjugated nanoliposomes released the drug in a sustained manner and were capable of distributing them in various organs. This may be used for cell/ tissue targeting, attaching specific antibodies to PE.

Preparation and characterization of Tamoxifen citrate loaded nanoparticles for breast cancer therapy

Background Four formulations of Tamoxifen citrate loaded polylactide-co-glycolide (PLGA) based nanoparticles (TNPs) were developed and characterized. Their internalization by Michigan Cancer Foundation-7 (MCF-7) breast cancer cells was also investigated. Methods Nanoparticles were prepared by a multiple emulsion solvent evaporation method. Then the following studies were carried out: drug-excipients interaction using Fourier transform infrared spectroscopy (FTIR), surface morphology by field emission scanning electron microscopy (FESEM), zeta potential and size distribution using a Zetasizer Nano ZS90 and particle size analyzer, and in vitro drug release. In vitro cellular uptake of nanoparticles was assessed by confocal microscopy and their cell viability (%) was studied. Results No chemical interaction was observed between the drug and the selected excipients. TNPs had a smooth surface, and a nanosize range (250–380 nm) with a negative surface charge. Drug loadings of the prepared particles were 1.5%±0.02% weight/weight (w/w), 2.68%±0.5% w/w, 4.09%±0.2% w/w, 27.16%±2.08% w/w for NP1–NP4, respectively. A sustained drug release pattern from the nanoparticles was observed for the entire period of study, ie, up to 60 days. Further, nanoparticles were internalized well by the MCF-7 breast cancer cells on a concentration dependent manner and were present in the cytoplasm. The nucleus was free from nanoparticle entry. Drug loaded nanoparticles were found to be more cytotoxic than the free drug. Conclusion TNPs (NP4) showed the highest drug loading, released the drug in a sustained manner for a prolonged period of time and were taken up well by the MCF-7 breast cancer cell line in vitro. Thus the formulation may be suitable for breast cancer treatment due to the good permeation of the formulation into the breast cancer cells.

Colloidal gold-loaded, biodegradable, polymer-based stavudine nanoparticle uptake by macrophages: an in vitro study.

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Development of an inhalation chamber and a dry powder inhaler device for administration of pulmonary medication in animal model

Context: Pulmonary route of administration is becoming more popular for drug delivery in pulmonary tract and lungs for local and systemic actions. Objective: A dry powder inhaler (DPI) for delivery of dry powder and a nose-only inhalation chamber for small animals that can be used with nebuliser/DPI were designed. Materials and methods: The inhalation chamber was made with a polypropylene-rectangular box and centrifuge tubes. DPI was made of a polypropylene tube. Micronized voriconazole and voriconazole solution were used for DPI and nebulizer, respectively, for both in vitro and in vivo studies. Results: In vitro drug deposition from nebulizer was found to be 11–26% w/w and that from DPI was 42 to 57% w/w depending on experimental set up. Uniform deposition across all the inhalation ports was observed irrespective of the methods. Respirable fraction (RF) varied from 34 to 73% in case of nebulizer and from 47 to 54% in case of DPI. In vivo deposition of voriconazole in lungs was found to be 80–130 µg/g of lung tissue in case of DPI and 40–68 µg/g of lung tissue in case of using nebulizer. Discussion: DPI designed was efficient in fluidizing powder bed and dispensing dry powder for inhalation. The inhalation chamber designed was efficient in uniformly distributing drug in various inhalation ports of the chamber. Conclusions: The DPI and inhalation chamber designed can be successfully used for inhalation study with multiple animals especially mice.

Pulmonary Delivery of Voriconazole Loaded Nanoparticles Providing a Prolonged Drug Level in Lungs: A Promise for Treating Fungal Infection.

Current therapies are insufficient to prevent recurrent fungal infection especially in the lower part of the lung. A careful and systematic understanding of the properties of nanoparticles plays a significant role in the design, development, optimization, and in vivo performances of the nanoparticles. In the present study, PLGA nanoparticles containing the antifungal drug voriconazole was prepared and two best formulations were selected for further characterization and in vivo studies. The nanoparticles and the free drug were radiolabeled with technetium-99m with 90% labeling efficiency, and the radiolabeled particles were administered to investigate the effect on their blood clearance, biodistribution, and in vivo gamma imaging. In vivo deposition of the drug in the lobes of the lung was studied by LC-MS/MS study. The particles were found to be spherical and had an average hydrodynamic diameter of 300 nm with a smooth surface. The radiolabeled particles and the free drug were found to accumulate in various major organs. Drug accumulation was more pronounced in the lung in the case of administration of the nanoparticles than that of the free drug. The free drug was found to be excreted more rapidly than the nanoparticle containing drug following the inhalation route as assessed by gamma scintigraphy study. Thus, the study reveals that pulmonary administration of nanoparticles containing voriconazole could be a better therapeutic choice even as compared to the iv route of administration of the free drug and/or the drug loaded nanoparticles.

Editorial (Thematic Issue: “Nanosize Drug Delivery System”)

Nanosize materials provide hopes, speculations and chances for an unprecedented change in drug delivery in near future. Nanotechnology is an emerging field to produce nanomaterials for drug delivery that can offer a new tool, opportunities and scope to provide more focused and fine-tuned treatment of diseases at a molecular level, enhancing the therapeutic potential of drugs so that they become less toxic and more effective. Nanodimensional drug delivery systems are of great scientific interest as they project their tremendous utility because of their capability of altering biodistribution of therapeutic agents so that they can concentrate more in the target tissues. Nanosize drug delivery systems generally focus on formulating bioactive molecules in biocompatible nanosystems such as nanocrystals, solid lipid nanoparticles, nanostructure lipid carriers, lipid drug conjugates, nanoliposomes, dendrimers, nanoshells, emulsions, nanotubes, quantum dots etc. Extensively versatile molecules like synthetic chemicals to naturally occurring complex macromolecules such as nucleic acids and proteins could be dispensed in such formulations maintaining their stability and efficacy. Empty viral capsids are being tried to deliver drug as these uniformly sized bionanomaterials can be utilized to load drug to improve solubility, reduce toxicity and provide site specific targeting. Nanomedicines offer a wide scope for delivery of smart materials from tissue engineering to more recently artificial RBCs. Nanocomposites are the future hope for tailored and personalized medicines as well as for bone repairing and rectification of cartilage impairment. Nanosize drug delivery systems are addressing the challenges to overcome the delivery problems of wide ranges of drugs through their narrow submicron particle size range, easily manipulatable surface characteristics in achievement of versatile tissue targeting (includes active and passive drug targeting), controlled and sustained drug release property to achieve increased therapeutic efficacy and reduced side effects. Nanoparticles and nanoliposomes are emerging areas of nanotechnologies that have already begun to make an impact over new modalities for cancer chemotherapy, diagnosis as well as gene delivery. Presently it is possible to reduce the particle size in such a way that the particles can be easily injected or inhaled and many types of human cells are capable to internalize them. A number of fabrications such as PEGylation, specific antibody conjugation, aptamer ligation, specific ligand binding etc. on the nanosize delivery devices makes them in the streamline of research to particularly target the diseased cells thus avoiding the healthy one. Potential of nanosize carriers to cross the blood brain barrier encourages us to build up a new strategy for delivery of therapeutically active agents to the brain. Nanotechnology is showing an emerging effect in chronic diseases such as diabetes, cancer, neurodegenerative diseases etc. Nanosize vaccines are having greater effect in production of better immunity against pathogens through direct administration of medication to the specialized dendritic cells in the immune systems. Lots of hopes and speculations are reigning around the scientists with nanosize drug delivery systems that may revolutionize the drug delivery with the better understanding of drug action mechanism and identification of biomarker associated with specific diseases. Nanosize drug delivery systems are emerging with the promising strategies for efficient targeted drug delivery. The proper designing of these systems can make them capable for being independent in the normal tissue environments and selective at the diseased pharmacological site. Nanomaterials as formulations are already in the market or in clinical trials. Investigation on nanostructural drug delivery is a highly growing field today as an extensive amount of research is on with an expectation to open up new avenues to drug delivery. No doubt the next era of drug therapy will be greater influenced by nanoscale drug delivery systems. However these newer systems for delivery of bioactive molecules must be reliable, efficient and safe.