Formulation of essential oil-loaded chitosan-alginate nanocapsules.

Naturally occurring polymers such as alginate (AL) and chitosan (CS) are widely used in biomedical and pharmaceutical fields in various forms such as nanoparticles, capsules, and emulsions. These polymers have attractive applications in drug delivery because of their biodegradability, biocompatibility, and nontoxic nature. The pharmaceutical applications of essential oils such as turmeric oil and lemongrass oil are well-known, and their active components, ar-turmerone and citral, respectively, are known for their antibacterial, antifungal, antioxidant, antimutagenic, and anticarcinogenic properties. However, these essential oils are unstable, volatile, and insoluble in water, which limits their use for new formulations. Therefore, this study focuses on developing a CS-AL nanocarrier for the encapsulation of essential oils. The effects of process parameters such as the effect of heat and the concentrations of AL and CS were investigated. Various physicochemical characterization techniques such as scanning electron microscopy, Fourier transform infrared spectroscopy, and ultraviolet-visible spectroscopy were performed. Results of characterization studies showed that 0.3 mg/mL AL and 0.6 mg/mL CS produced minimum-sized particles (<300 nm) with good stability. It was also confirmed that the oil-loaded nanocapsules were hemocompatible, suggesting their use for future biomedical and pharmaceutical applications. Furthermore, the antiproliferative activity of turmeric oil- and lemongrass oil-loaded nanocapsules was estimated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay in A549 cell lines and it was found that both the nanoformulations had significant antiproliferative properties than the bare oil.

Highly selective colorimetric detection and estimation of Hg2+ at nano-molar concentration by silver nanoparticles in the presence of glutathione.

The present study investigated the colorimetric detection of mercury (Hg(2+)) ions by using silver nanoparticles (Ag NPs) in the presence of glutathione. The nanoparticles used in the study were synthesized biologically by using Polyalthia longifolia leaf extract. The synthesized nanoparticles were characterized by UV-visible spectrophotometer, transmission electron microscope, X-ray diffraction, particle size analyzer and zeta sizer. The particles were spherical in shape and it possesses the effective diameter of 5 nm. The zeta potential of the particles was determined to be -28.6 mV. Ag NPs-glutathione conjugates were able to detect Hg(2+) in nanomolar level. Ag NPs-glutathione conjugates upon interaction with Hg(2+) changes from yellowish brown to pale yellow and finally colorless. The study may be applied for the qualitative and quantitative estimation of mercury at very low concentration.

Metformin-loaded BSA nanoparticles in cancer therapy: a new perspective for an old antidiabetic drug.

Clinical and experimental data suggest that there is a strong association between type II diabetic mellitus and pancreatic cancer. The present study focuses on exploring the anticancer and antidiabetic properties of metformin-loaded bovine serum albumin nanoparticles (BSA NPs) on (MiaPaCa-2) pancreatic carcinoma cell lines. Albumin nanoparticles were synthesized using coacervation method and the average size of the particles was found to be 97 nm. The particles were stable and showed a spherical morphology with narrow size distribution. We investigated the impact of two stages characterized in type II diabetes mellitus (hyperglycemia and hyperinsulinemia) on the proliferation of MiaPaCa-2 cells and compared the inhibitory effects of bare metformin to that of MET-BSA NPs. Further, different concentrations of insulin and glucose were added along with bare metformin, bare BSA, and metformin encapsulated BSA carrier on MiaPaCa-2 cells to check the strong association between type II diabetes and pancreatic cancer. The results revealed that MET-BSA NPs showed more toxicity when compared with drug and carrier individually.

Effect of exopolysaccharides on photocatalytic activity of ZnO nanoparticles.

Zinc oxide nanoparticles (ZnO NPs) are largely used in consumer products and industrial applications. The increased use of such materials may lead to its release into the environment. The study used chemically synthesized ZnO NPs and characterized by using UV-visible spectrophotometer, scanning electron microscopy, particle size analyzer and X-ray diffraction (XRD) analysis. The mean diameter of the particles was found to be 55±1.2nm. The XRD patterns exhibited hexagonal structure for ZnO NPs. The photocatalytic property of ZnO NPs was evaluated based on the UV-vis spectra changes of the methylene blue solution as a function of reaction time in the presence of ZnO NPs under visible light. The study suggests that ZnO NPs can be used as an efficient photocatalyst and the environmental factor such as exopolysaccharides could mask the photocatalytic activity of NPs.

Recent trends in drug delivery system using protein nanoparticles.

Engineered nanoparticles that can facilitate drug formulation and passively target tumours have been under extensive research in recent years. These successes have driven a new wave of significant innovation in the generation of advanced particles. The fate and transport of diagnostic nanoparticles would significantly depend on nonselective drug delivery, and hence the use of high drug dosage is implemented. In this perspective, nanocarrier-based drug targeting strategies can be used which improve the selective delivery of drugs to the site of action, i.e. drug targeting. Pharmaceutical industries majorly focus on reducing the toxicity and side effects of drugs but only recently it has been realised that carrier systems themselves may pose risks to the patient. Proteins are compatible with biological systems and they are biodegradable. They offer a multitude of moieties for modifications to tailor drug binding, imaging or targeting entities. Thus, protein nanoparticles provide outstanding contributions as a carrier for drug delivery systems. This review summarises recent progress in particle-based therapeutic delivery and discusses important concepts in particle design and biological barriers for developing the next generation of particles drug delivery systems.

BSA nanoparticle loaded atorvastatin calcium--a new facet for an old drug.

BACKGROUND: Currently, the discovery of effective chemotherapeutic agents poses a major challenge to the field of cancer biology. The present study focuses on enhancing the therapeutic and anti cancer properties of atorvastatin calcium loaded BSA (ATV-BSA) nanoparticles in vitro. METHODOLOGY/RESULTS: BSA-ATV nanoparticles were prepared using desolvation technique. The process parameters were optimized based on the amount of desolvating agent, stabilization conditions as well as the concentration of the cross linker. The anti cancer properties of the protein coated ATV nanoparticles were tested on MiaPaCa-2 cell lines. In vitro release behavior of the drug from the carrier suggests that about 85% of the drug gets released after 72 hrs. Our studies show that ATV-BSA nanoparticles showed specific targeting and enhanced cytotoxicity to MiaPaCa-2 cells when compared to the bare ATV. CONCLUSION: We hereby propose that the possible mechanism of cellular uptake of albumin bound ATV could be through caveolin mediated endocytosis. Hence our studies open up new facet for an existing cholesterol drug as a potent anti-cancer agent.

Mechanistic insights into interaction of humic acid with silver nanoparticles.

Humic acid (HA) is one of the major components of the natural organic matter present in the environment that alters the fate and behavior of silver nanoparticles (Ag NPs). Transformation of Ag NPs happens upon interaction with HA, thereby, changing both physical and chemical properties. Fluorescence spectroscopy and scanning electron microscopy (SEM) were used to analyze the interaction of Ag NPs with HA. In pH and time-dependent studies, the near field electro dynamical environment of Ag NPs influenced the fluorescence of HA, indicated by fluorescence enhancement. SEM revealed not only morphological changes, but also significant reduction in size of Ag NPs after interaction with HA. Based on these studies, a probable mechanism was proposed for the interaction of HA with Ag NPs, suggesting the possible transformation that these nanoparticles can undergo in the environment.

Biofunctionalized silver nanoparticles: advances and prospects.

The unique size-dependent properties of nano scale materials have significantly impacted all spheres of human life making nanotechnology a promising field for biomedical applications. Metal nanoparticles like silver have gained significant interest over the years due to their remarkable optical, electrical and antimicrobial properties. However, the toxic nature and aggregation of these nanoparticles has limited its use in more optimized applications. Rational selection of therapeutically active biomolecules for functionalizing the surface of these particles will certainly increase the biocompatibility and biological applicability. The current review attempts to stress on the application domains of silver nanoparticles and also extends an overview on the current strategies involved in biofunctionalizing these particles for specific applications. This review is divided into three sections. The first section emphasizes the importance of silver nanoparticles and its biomedical applications. The need for functionalization and the various concepts and techniques involved in creating surface modified silver nanoparticles will be described in the second section; and the last section throws light on the various applications of the functionalized silver nanoparticles.

Selective colorimetric sensing of cysteine in aqueous solutions using silver nanoparticles in the presence of Cr³+.

We here in report an extensive study on the development of a highly facile, selective and sensitive colorimetric probe for cysteine detection using silver nanoparticles (Ag NPs). The efficacy of the process relies upon the surface plasmon resonance properties of Ag NPs and the interaction of Ag-cysteine complex with chromium ions (Cr(3+)) in a ratio of 2:1. In the presence of Cr(3+), cysteine was able to induce the aggregation of Ag NPs thereby resulting in a change in yellow colour of the Ag colloid to purple. The reported probe has a limit of detection down to 1 nM which is to the best of our knowledge the lowest ever reported for the colorimetric detection of cysteine. Furthermore, a remarkable feature of this method is that it involves a simple technique exhibiting high selectivity to cysteine over other tested amino acids.

Studies on interaction of colloidal Ag nanoparticles with Bovine Serum Albumin (BSA).

Biofunctionalization of noble metal nanoparticles like Ag, Au is essential to obtain biocompatibility for specific biomedical applications. Silver nanoparticles are being increasingly used in bio-sensing applications owing to excellent optoelectronic properties. Among the serum albumins, the most abundant proteins in plasma, a wide range of physiological functions of Bovine Serum Albumin (BSA) has made it a model system for biofunctionalization. In absence of adequate prior reports, this study aims to investigate the interaction between silver nanoparticles and BSA. The interaction of BSA [0.05-0.85% concentrations] with Ag nanoparticles [50ppm concentration] in aqueous dispersion was studied through UV-vis spectral changes, morphological and surface structural changes. At pH 7, which is more than the isoelectric point of BSA, a decrease in absorbance at plasmon peak of uninteracted nanoparticles (425nm) was noted till 0.45% BSA, beyond that a blue shift towards 410nm was observed. The blue shift may be attributed to enhanced electron density on the particle surfaces. Increasing pH to 12 enhanced the blue shift further to 400nm. The conformational changes in BSA at alkaline pH ranges and consequent hydrophobic interactions also played an important role. The equilibrium adsorption data fitted better to Freundlich isotherm compared to Langmuir curve. The X-ray diffraction study revealed complete coverage of Ag nanoparticles by BSA. The scanning electron microscopic study of the interacted nanoparticles was also carried out to decipher morphological changes. This study established that tailoring the concentration of BSA and pH of the interaction it was possible to reduce aggregation of nanoparticles. Biofunctionalized Ag nanoparticles with reduced aggregation will be more amenable towards bio-sensing applications.