Current Nanomaterials - Volume 4, Issue 2, 2019

Background: A lot of people are facing some health-related problems in day to day life. The conventional drug delivery is not able to cure it alone, moreover, some drugs have poor solubility, low half-life and show lesser bioavailability. It is necessary to conduct research on carrier-based nanoparticulate drug delivery, this is an alternative approach to alter/eliminate the problem of conventional dosing for better effectiveness, patient compliance, and effective drug targeting. Objective: To develop a carrier-based nanoparticulate drug delivery system for the elimination of problems associated with conventional dosage form. Methods: In this review, different problems associated with conventional dosage form as well as potential advantages of the nanoparticulate delivery systems have been discussed. We also discussed their different route for administration such as oral, intranasal, ocular, transdermal, vaginal etc. for effective drug targeting. It has been found that different nanocarriers based drug delivery have been able to enhance the bioavailability, solubility, minimized adverse effect as well as effective in Gene delivery also. Ionic gelation, Solvent evaporation, emulsification, homogenization, lyophilisation, etc. are techniques used for their development. Conclusion: The carrier-based drug delivery technique act as an effective drug delivery system for the treatment of various diseases/disorders as well as provides better efficiency, bioavailability and improve patient compliance.

Brain tumors arise from an uncontrolled proliferation of neural tissue cells or supportive glial tissue cells within the brain. The diagnosis and therapy of brain tumor is an extremely challenging task. Moreover, absence of early stage symptoms and consequently delays in diagnosis and therapy worsen its severity. Though in the present days, chemotherapeutic approach is the most common therapeutic approach; still it is linked with several precincts. The blood-brain barrier (BBB) is the main hurdle in delivering most of the chemotherapeutic agents as well as imaging agent that leads to insufficient accumulation of therapeutic / imaging agents at tumor site, and prevents adequate destruction of malignant cells. Recently, lipid based nanoparticles are gaining much more interest and are preferred over polymeric nanoparticles owing to their biodegradability, non-toxicity, excellent tumortargeting ability and ease of surface modification. Certain receptors are over expressed in brain tumor cells which confer an opportunity to the researchers for delivering the chemotherapeutic as well as imaging agent particularly to the tumor cells through the surface modification approach of nanoparticles. Ligands like proteins/peptides, carbohydrates, aptamers, antibodies, and antibody fragments are generally conjugated to the surface of the nanoparticles that bind specifically to an over expressed target on the brain tumor cell surface. In the present review, we discuss the diagnostic and therapeutic application of various types of lipid based nanoparticles such as liposomes, niosomes, solid lipid nanoparticles, nanostructured lipid carrier, lipid nanocapsule, and lipid polymer hybrid nanocarriers along with their various surface modified forms for targeting brain tumor.

Background: Carbon dots are a new class of biomaterials that have found a wide range of biomedical applications like cell imaging, targeted delivery, and bio-sensing. A review of the literature reveals that there are fewer reports on nanocomposites prepared by entrapment of carbon dots into polymers. Objective: A tetra carboxylic acid compound, can conveniently be used as a precursor to synthesize negatively charged carbon dots. Methods: Carbon dots have been prepared by microwave induced treatment of BTCA so as to have carboxylic groups onto the surface of the carbon dots. Their size distribution was determined by TEM analysis. These CNPs are loaded into chitosan films by solvent casting approach. The water absorption behavior of chitosan/carbon dots nanocomposite films is investigated by gravimetric method. Results: The size of the CNPs was found to be in the range of 50 to 60 nm with almost spherical geometry. Their zeta potential was found to be -20.2 mV, thus indicating the presence of negative charges on their surface. The contact angle measurements revealed that wettability of plain chitosan film reduced due to the addition of carbon dots. It was found that impregnation of carbon nanoparticles (CNPs) into chitosan film resulted in an almost seven-fold decrease in the water absorption capacity of the film. The equilibrium moisture uptake (EMU) data of plain chitosan and CNPs-loaded chitosan films were interpreted by GAB isotherm and related parameters were also evaluated. Conclusion: It may be concluded from the above study that BTCA, a tetra carboxylic acid compound, can conveniently be used as a precursor to synthesize negatively charged carbon dots. These carbon dots, when loaded into plain chitosan film, cause an effective crosslinking within the chitosan film matrix. The CNPs-loaded films produce green fluorescence when exposed to UV light.

Background and Objective: In this study, dudoa (Hydnocarpus alcalae C.DC.) leaf extract was used as a reducing and stabilizing agent in a novel one-step green synthesis of silver nanoparticles. Dudoa is an endemic plant in the province of Legazpi, Philippines and its seed oil was used as an anti-leprotic drug. Methods: Therefore, the dudoa leaf extract was used to synthesize silver nanoparticles. Moreover, optimization of various parameters greatly affected the size and morphology of the synthesized AgNPs as indicated by the Ultraviolet-visible (UV-vis) spectrophotometry. The synthesized AgNPs were further characterized using spectral analyses such as XRD, EDX, SEM, FT-IR, TGA and DLS. The antimicrobial activity of synthesized AgNPs was also demonstrated. Results and Discussion: The synthesized AgNPs exhibited a diffraction pattern and a particle size ranging from 22-48 nm. The AgNPs also showed complete inhibitory and mild reactivity against representative pathogenic gram-positive (S.aureus) and gram-negative (E.coli) bacteria. Conclusion: Silver nanoparticles were successfully synthesized using H. alcalae leaf extract. Furthermore, this green synthesis approach appeared to be cost-effective, non-toxic, and eco-friendly which is a best alternative to the conventional chemical methods.

Background: The properties of spinel ferrites are known to be dependent on many various factors and mainly on the cations distribution among the tetrahedral and octahedral sites. Therefore, they are sensitive to the presence of doping cations, the type and the amount of these cations. Many researchers have focused on investigating the effect of doping on spinel ferrites nanoparticles with various types of dopants. Among the dopants, transition metal (TM) ions have shown significant effects and changes on the structural, optical, electric and magnetic properties of spinel ferrites nanoparticles. Objectives: The goal of this work is to investigate the effect of the TM ions Mo5+ on the several properties of manganese ferrites nanoparticles. Methods: Mo-doped manganese ferrites nanoparticles with the general formula MnFe2-xMoxO4 (0≤x≤ 0.1) were prepared by co-precipitation technique using two different methods, depending on the molarity of NaOH and the annealing temperatures. The characterization of the prepared samples was conducted by X-ray powder diffraction (XRD), Energy-Dispersive X-ray (EDX), Transmission Electron Microscopy (TEM), ultraviolet-visible (UV-Vis) absorption spectroscopy and Fourier Transform Infrared (FTIR) spectroscopy in order to investigate the effect of Mo-doping on the structure, crystallite size, morphology, energy gap and functional groups of MnFe2O4 nanoparticles. Vibrating sample magnetometer (VSM) was used to study the magnetic hysteresis of the samples. Results: The XRD patterns show the segregation of MnFe2O4 phase into α-Fe2O3 and Mn2O3 for samples prepared at 4 M NaOH and annealing temperature of 873 K. Whereas, samples prepared at 2 M NaOH without annealing process, obtained a single phase of MnFe2O4. The Eg of both samples decreases with the increase in Mo-doping. FTIR confirms the presence of Fe-O bands corresponding to α-Fe2O3 for annealed samples, and the metal-O bands corresponding to octahedral and tetrahedral sites in non-annealed samples. Magnetic measurements show that annealed samples are antiferromagnetic whereas ferromagnetic behavior is observed in non-annealed samples. Dielectric measurements, for both samples, indicate that the dielectric parameters are strongly dependent on both Mo-concentrations and temperatures. Conclusion: In order to get a single phase of MnFe2O4 nanoparticles, thermal treatment at high temperature and high molarity of NaOH are not recommended. Mo-doping has significant influences on the optical, magnetic and dielectric properties and therefore future studies on the Mo-doping with different and new doping percentages are recommended.

Background: Application of thermoreversible gel can be a solution to the low residence time of the topical dosage forms such as normal gel, ointment and cream on the skin surface. Addition of another polymer and a nanocomposite can improve the poor mechanical strength and fast drug release of poloxamer 407 (POL 407) gel. Therefore, it is essential to add xanthan gum (XG) and graphene oxide (GO, thickness 1-2 nm, lateral dimension 1-5 μm) to POL 407 gel to enhance the mechanical strength and to sustain the drug release from the gel. Methods: Thermal gel of ondansetron hydrochloride (OSH) containing nanocomposite was prepared by adopting cold method. Interaction between drug and polymers was studied using FTIR method, morphological investigation was carried out by optical and scanning electron microscopy method, and rheological study was performed employing rotational rheometer equipped with a cone/plate shear apparatus, gelation temperature by glass bottle method and ex vivo permeation study was performed with cylindrical glass diffusion cell. Skin irritation potential was measured using rat as a model animal. Results: The FTIR spectrum of the selected gel showed that there is shifting of O-H stretching vibration of a hydroxyl group from 3408.72 to 3360.49 cm-1 and appearance of a new band at 1083.01 cm-1. The spectrum of the selected gel also showed the absence of characteristic peaks of GO at 1625.49 cm- 1. This result indicated that there may be an interaction between OSH and GO and hydrogen bonding between XG and POL 407. The gelation temperature was found to be decreased with the increase in GO content from 14.1±1.21°C 13±0.97°C. SEM micrograph demonstrated the uniform dispersion and intercalation of GO sheets in the gel. All the gel formulations showed a pseudo-plastic flow. Ex vivo permeation study (for 24 hr) exhibited highest (6991.425 μg) and lowest (2133.262 μg) amount of drug release, for OG1 and OG5, respectively. This is attributed to an increase in viscosity which led to a decrease in drug permeation across the abdominal skin of rats. The OG1 formulation (without GO) showed the highest flux of 76.66 μg/cm2/h, permeability coefficient (Kp) of 5.111× 10-3 cm/h and enhancement ratio of 3.277 compared to OG5 containing highest amount (9% w/w) of GO. The selected gel was found to be physically stable and there was minimum irritation score. Conclusion: All the above results indicated that thermal gel containing nanocomposite sustained the drug release and can be considered as an alternative to the orally administered tablet of OSH.