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Poor drug solubility and bioavailability remain a significant and frequently encountered concern for pharmaceutical scientists. Nanoscaled lipid drug delivery systems (NSLDDS) have exhibited great potentials in oral delivery of poorly water-soluble drugs, primarily for lipophilic drugs, with several successful clinical products. In the past few years, we have find out that optimized composition of drug in lipid, surfactant, or mixture of lipid and surfactant omits the solubility, permeability and bioavailability issues, which are potential limitations for oral absorption of poorly water-soluble drugs. Lipids not only vary in structures and physiochemical properties, but also in their digestibility and absorption pathway; therefore selection of lipid excipients and dosage form has a pronounced effect on biopharmaceutical aspects of drug absorption and distribution both in vitro and in vivo. Therefore, in current critical review, a comprehensive overview of the different lipid based nanostructured drug delivery systems intended for oral administration has been presented. In addition, implication of in silico docking in designing of NSLDDS as well as mechanism of absorption of different lipid based nanoformulations through intestinal absorption window has also been offered. Moreover, attention has also been paid to NSLDDS that are currently undergoing preclinical or clinical analysis., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Chloroquine diphosphate (CHQ) is primarily used for the treatment of Plasmodium falciparum malaria at the dose of 500mg orally or 10mg/kg parenterally. However, point mutations in Plasmodiumfalciparum chloroquine resistance transporter (PfCRT) protein and Plasmodium falciparum multidrug resistance protein 1 (Pfmdr1) localized in digestive vacuole membrane, are responsible for CHQ resistance. Therefore, in present investigation, dextran nanoparticles bearing chloroquine diphosphate (CHQ-DEX-NPs) were formulated by solvent diffusion method of size below 70nm with zeta-potential of -20.1±3.2mV. FT-IR, DSC and PXRD techniques confirmed the successful loading of drug in nanomatrix system with amorphous attributes. In vitro drug release analysis indicated the Higuchi pattern with diffusion controlled drug release. The IC 50 of CHQ-DEX-NPs in sensitive (3D7) and resistant (RKL9) Plasmodium falciparum strains was estimated to be 0.031-μg/ml and 0.13-μg/ml significantly lower than 0.059-μg/ml and 0.36-μg/ml of CHQ. The augmented therapeutic efficacy of CHQ-DEX-NPs may be credited to deposition of tailored nanoparticles in food vacuoles of malaria parasites owing to the affinity of parasite towards DEX that consequently lower the drug resistance and improved the therapeutic index. In conclusion, CHQ-DEX-NPs must be evaluated under a set of stringent in vivo parameters to establish its therapeutic efficacy in preclinical model., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background and Objective: In a phase II clinical trial, carboplatin (CBDCA) displayed the response rate of 19% equivalent to dacarbazine in the treatment of malignant melanoma. However, besides desirable therapeutic profile, intravenous (i.v) administration of CBDCA delivers a subtherapeutic concentration at the target site. This entails administration of CBDCA through an alternate route by using nanovectors to achieve therapeutic efficacy in the treatment of melanoma., Methods and Results: Carboplatin loaded poly(ε-caprolactone) nanoparticles (CBDCA-PCL-NPs) were formulated and amalgamated with chitosan-β-glycerophosphate gel (CBDCA-PCL-NPs-Gel) for intratumoral (i.t) administration. The mean particle size and zeta-potential of CBDCA-PCL-NPs were determined to be 54.5 ± 6.3-nm and -8.1 ± 0.9-mV, in addition to spherical shape of the nanoformulation. FT-IR spectroscopy denied any issue of chemical incompatibility between drug and polymer. XRD pattern indicated the amorphous lattice of CBDCA-PCL-NPs. The drug loading capacity of CBDCA-PCL-NPs-Gel was estimated to be 152 mg/1 ml. CBDCA-PCL-NPs-Gel demonstrated prolonged drug release up to 48 h. Furthermore, CBDCA-PCL-NPs-Gel displayed the IC 50 of 80.3-μM significantly (P < 0.05) lower than 162.8-μM of CBDCA-PCL-NPs and 248.5-μM of CBDCA solution in B16F1, melanoma cancer cells. CBDCA-PCL-NPs-Gel verified 80.2% of apoptosis significantly (P < 0.01) higher than 57.6% of CBDCA-PCL-NPs and 43.4% of CBDCA solution. Continuation to this, CBDCA-PCL-NPs-Gel significantly (P < 0.01) suppressed the tumor volume to 95.5 ± 8.4-mm 3 as compared to 178.9 ± 10.2-mm 3 of CBDCA solution injected i.t. and 210.6 ± 17.1-mm 3 displayed by CBDCA solution injected i.v. vis-à-vis 815.4 ± 17.1-mm 3 tumor volume of B16F1 tumor bearing C57BL6J mice., Conclusion: The promising preclinical results of CBDCA-PCL-NPs-Gel warrant further investigations under a set of stringent parameters for the treatment of melanoma., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background and Objective: 5-Fluorouracil (5-FU) is a first-line chemotherapeutic drug in colorectal cancer. However, intravenous administration of 5-FU at the dose of 7-12mg/kg exhibits curbs like short half-life (20min) and toxic side-effects on bone marrow cells. Therefore, in present investigation, 5-FU was conjugated to poly (ethylene glycol) anchored recombinant human serum albumin nanoparticles (5-FU-rHSA-PEG-NPs) to improve the pharmacokinetic and therapeutic profiles., Methods and Results: The mean particle size of 5-FU-rHSA-NPs was measured to be 44.3±5.8-nm, significantly (P<0.05) lesser than 65.7±7.2-nm of 5-FU-rHSA-PEG-NPs. In addition, zeta-potential of 5-FU-rHSA-NPs was estimated to be -10.2±2.6-mV significantly (P<0.05) lower than -25.8±3.5-mV of 5-FU-rHSA-PEG-NPs. Moreover, both 5-FU-rHSA-NPs and 5-FU-rHSA-PEG-NPs were smooth, spherical and regular in shape. In-vitro drug release analysis indicated that 5-FU-rHSA-NPs and 5-FU-rHSA-PEG-NPs separately released 10.9% and 9.23% of 5-FU in PBS (pH∼7.4) with no significant difference (P>0.05) up to 48h. However, addition of 20% v/v serum to PBS (pH∼7.4) boosted the drug release. 5-FU-rHSA-NPs and 5-FU-rHSA-PEG-NPs released 78.26% and 48.9% of the 5-FU up to 48h in presence of PBS (pH∼7.4 and 20% serum) with significant difference (P<0.05). Furthermore, 5-FU-rHSA-PEG-NPs displayed the IC 50 of 3.7-μM significantly (P<0.05) lower than 6.8-μM and 11.2-μM of 5-FU-rHSA-NPs and 5-FU solution, respectively. One compartmental pharmacokinetic elements indicated that 5-FU-rHSA-PEG-NPs demonstrated the half-life (t 1/2 ) of 5.33±0.15-h significantly (P<0.001) higher than 1.50±0.08-h and 0.30±0.09-h of 5-FU-rHSA-NPs and 5-FU solution, respectively., Conclusion: 5-FU-rHSA-PEG-NPs tendered improved cytotoxicity and pharmacokinetic profile. Hence, 5-FU-rHSA-PEG-NPs must be further tested under stringent milieu for translating in to a clinical product., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Purpose: Noscapine (Nos) and reduced brominated analogue of noscapine (Red-Br-Nos) prevent cellular proliferation and induce apoptosis in cancer cells either alone or in combination with other chemotherapeutic drugs. However, owing to poor physicochemical properties, Nos and Red-Br-Nos have demonstrated their anticancer activity at higher and multiple doses. Therefore, in present investigation, silver nanocrystals of noscapinoids (Nos-Ag 2+ nanocrystals and Red-Br-Nos-Ag 2+ nanocrystals) were customized to augment drug delivery, cytotoxicity, apoptosis and cellular uptake in B16F1 mouse melanoma cancer cells., Methods and Results: Nos-Ag 2+ nanocrystals and Red-Br-Nos-Ag 2+ nanocrystals were prepared separately by precipitation method. The mean particle size of Nos-Ag 2+ nanocrystals was measured to be 25.33±3.52nm, insignificantly (P>0.05) different from 27.43±4.51nm of Red-Br-Nos-Ag 2+ nanocrystals. Furthermore, zeta-potential of Nos-Ag 2+ nanocrystals was determined to be -25.3±3.11mV significantly (P<0.05) different from -15.2±3.33mV of Red-Br-Nos-Ag 2+ nanocrystals. The shape of tailored nanocrystals was slightly spherical and or irregular in shape. The architecture of Nos-Ag 2+ nanocrystals and Red-Br-Nos-Ag 2+ nanocrystals was crystalline in nature. FT-IR spectroscopy evinced the successful interaction of Ag 2+ nanocrystals with Nos and Red-Br-Nos, respectively. The superior therapeutic efficacy of tailored nanocrystals was measured in terms of enhanced cytotoxicity, apoptosis and cellular uptake. The Nos-Ag 2+ nanocrystals and Red-Br-Nos-Ag 2+ nanocrystals exhibited an IC 50 of 16.6μM and 6.5μM, significantly (P<0.05) lower than 38.5μM of Nos and 10.3μM of Red-Br-Nos, respectively. Finally, cellular morphological alterations in B16F1 cells upon internalization of Nos-Ag 2+ nanocrystals and Red-Br-Nos-Ag 2+ nanocrystals provided the evidences for accumulation within membrane-bound cytoplasmic vacuoles and in enlarged lysosomes and thus triggered mitochondria mediated apoptosis via caspase activation., Conclusion: Preliminary investigations substantiated that Nos-Ag 2+ nanocrystals and Red-Br-Nos-Ag 2+ nanocrystals must be further explored and utilized for the delivery of noscapinoids to melanoma cancer cells., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Efficient delivery of therapeutic nanoparticles (TNPs) to tumors is critical in improving efficacy, yet strategies that universally maximize tumoral targeting by TNP modification have been difficult to achieve in the clinic. Instead of focusing on TNP optimization, we show that the tumor microenvironment itself can be therapeutically primed to facilitate accumulation of multiple clinically relevant TNPs. Building on the recent finding that tumor-associated macrophages (TAM) can serve as nanoparticle drug depots, we demonstrate that local tumor irradiation substantially increases TAM relative to tumor cells and, thus, TNP delivery. High-resolution intravital imaging reveals that after radiation, TAM primarily accumulate adjacent to microvasculature, elicit dynamic bursts of extravasation, and subsequently enhance drug uptake in neighboring tumor cells. TAM depletion eliminates otherwise beneficial radiation effects on TNP accumulation and efficacy, and controls with unencapsulated drug show that radiation effects are more pronounced with TNPs. Priming with combined radiation and cyclophosphamide enhances vascular bursting and tumoral TNP concentration, in some cases leading to a sixfold increase of TNP accumulation in the tumor, reaching 6% of the injected dose per gram of tissue. Radiation therapy alters tumors for enhanced TNP delivery in a TAM-dependent fashion, and these observations have implications for the design of next-generation tumor-targeted nanomaterials and clinical trials for adjuvant strategies., (Copyright © 2017, American Association for the Advancement of Science.)

Context: RNA interference (RNAi)-based therapeutics rely upon safe and efficient delivery of small interfering RNA (siRNA) molecules., Objective: This review explores various dimensions of RNAi with emphasis on the development of nanoparticle-based delivery vectors for safe and efficient siRNA delivery., Methods: An exhaustive database search has been done regarding studies done to investigate the potential of siRNA delivery employing nanoparticles has been cited in the present review., Results and Conclusion: With the current challenges, there is a need for collaborative work allowing for the successful development of nanoparticle/siRNA complexes as health-promoting biotherapeutics.

Context: The size of nanoparticles plays a pivotal role in determining the gene delivery efficiency., Objective: A focus on the studies done to investigate the effect of nanoparticles size on biological aspects of gene delivery., Methods: A through literature survey has been done regarding studies done to investigate the effect of nanoparticles size on uptake, transfection efficiency and biodistribution has been cited in the present review., Results and Conclusion: The gene delivery efficacy may depend on conjugation of several factors such as the chemical structure of polymers, cell type, and nanoparticle size, composition and interaction with cells.

Context: Polymers have been largely explored for the preparation of nanoparticles due to ease of preparation and modification, large gene/drug loading capacity, and biocompatibility. Various methods have been adapted for the preparation and characterization of chitosan nanoparticles., Objective: Focus on the different methods of preparation and characterization of chitosan nanoparticles., Methods: Detailed literature survey has been done for the studies reporting various methods of preparation and characterization of chitosan nanoparticles., Results and Conclusion: Published database suggests of several methods which have been developed for the preparation and characterization of chitosan nanoparticles as per the application.

9-Bromo-noscapine (9-Br-Nos) alters tubulin polymerization in non-small cell lung cancer cells differently from noscapine. However, clinical applications of 9-Br-Nos are limited owing to poor aqueous solubility and high lipophilicity that eventually lead to suboptimal therapeutic efficacy at the site of action. Hence, 9-Br-Nos loaded nanostructured lipid particles (9-Br-Nos-NLPs) were prepared by nanoemulsion method to reduce the particle size below 100 nm. To impart the inhalable and rapid release (RR) attributes, 9-Br-Nos-NLPs were treated with spray dried lactose and effervescent excipients to generate, 9-Br-Nos-RR-NLPs. The mean particle and aerodynamic size of 9-Br-Nos-NLPs were measured to be 13.4±3.2 nm and 2.3±1.5 μm, significantly (P<0.05) lower than 19.4±6.1 nm and 3.1±1.8 μm of 9-Br-Nos-RR-NLPs. In addition, zeta-potential of 9-Br-Nos-NLPs was examined to be -9.54±0.16 mV, significantly (P<0.05) lower than -7.23±0.10 mV of 9-Br-Nos-RR-NLPs. Hence, both formulations were found to be optimum for pulmonary delivery through inhalation route of administration. Next, 9-Br-Nos-RR-NLPs exhibited enhanced cytotoxicity, apoptosis and cellular uptake in A549, lung cancer cells, as compared to 9-Br-Nos-NLPs and 9-Br-Nos suspension. This may be attributed to enhanced drug delivery and internalization character of 9-Br-Nos-RR-NLPs by energy-dependent endocytosis and passive diffusion mechanism. Pharmacokinetic and distribution analysis demonstrated the superiority of 9-Br-Nos-RR-NLPs that exhibited ∼1.12 and ∼1.75-folds enhancement in half-life of the drug as compared to 9-Br-Nos-NLPs and 9-Br-Nos powder following inhalation route. Continuation to this, 9-Br-Nos-RR-NLPs also displayed ∼3.75-fold increment in half-life of the drug in lungs, as compared to 9-Br-Nos suspension following intravenous route of administration. Furthermore, enhanced drug exposure was measured in terms of AUC(last) in lungs following administration of 9-Br-Nos-RR-NLPs, as compared to 9-Br-Nos-NLPs, 9-Br-Nos powder and 9-Br-Nos suspension. This may be attributed to rapid dispersion, enhanced dissolution and deep lung deposition of nanoparticles following inhalation route. Therefore, inhalable 9-Br-Nos-RR-NLPs claims further in depth in vivo tumor regression study to scale up the technology for clinical applications., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background and Objectives: Non-aggregated protamine impregnated poly(lactide-co-glycolide) nanoparticles of cisplatin (Pt-PLGA NPs) were synthesized to augment brain delivery., Methods and Results: The mean particle size of Pt-PLGA NPs and PLGA NPs were observed to be 173.2 ± 7.9 nm and 140 ± 10.2 nm, respectively. The Pt-PLGA NPs significantly (p < 0.05, one-way analysis of variance; ANOVA) delivered higher amount (172.41 ± 15.04 μg) of cisplatin in comparison to 110.48 ± 4.71 μg by PLGA NPs and 20.83 ± 1.65 μg by cisplatin solution across in vitro bovine brain microvessel endothelial cells. Cisplatin bearing Pt-PLGA NPs was found to be highly cytotoxic to U87 glioblastoma cells with an IC50 of 2.1 μM as compared (one-way ANOVA, p < 0.05) to PLGA NPs (3.9 μM) and cisplatin alone (13.33 μM). Impregnation with Pt enhanced the uptake of PLGA NPs in U87 glioblastoma cells as compared to PLGA NPs by following endocytosis mechanism., Conclusion: Cisplatin-loaded Pt-PLGA NPs compel preclinical tumour regression study to further improve its utility against glioblastoma.

Noscapine crosses blood-brain-barrier and inhibits proliferation of glioblastoma cells. However, short plasma half-life and rapid elimination necessitate the administration of multiple injections for successive chemotherapy. Noscapine bearing solid lipid nanoparticles, Nos-SLN and poly (ethylene)-glycol conjugated solid lipid nanoparticles of noscapine, Nos-PEG-SLN of 61.3 ± 9.3-nm and 80.5 ± 8.9-nm containing 80.4 ± 3.2% and 83.6 ± 1.2% of Nos, were constructed. First order kinetic and Higuchi equation were followed to release the Nos at intracellular pH~4.5. Further, a decrease in IC₅₀ (Nos; 40.5 μM>Nos-SLN; 27.2 μM>20.8 μM) and enhanced subG1 population were observed in U87cells. Plasma half-life was enhanced up to ~11-fold and ~5-fold by Nos-PEG-SLN and Nos-SLN which significantly (P<0.05) deposits 400.7 μg/g and 313.1 μg/g of Nos in comparison to 233.2 μg/g by drug solution. This is first report demonstrating a workable approach to regulate the administration of multiple injections of Nos, warranting further in vivo tumor regression study for superior management of brain cancer., From the Clinical Editor: This report describes a possible approach to regulate the administration of multiple injections of Noscapine using solid lipid nanoparticles. The data warrant further in vivo tumor regression studies for optimal management of glioblastoma, a generally very poorly treatable brain cancer., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Noscapine, a tubulin binding anticancer agent undergoing Phase I/II clinical trials, inhibits tumor growth in nude mice bearing human xenografts of breast, lung, ovarian, brain, and prostrate origin. The analogues of noscapine like 9-bromonoscapine (EM011) are 5 to 10-fold more active than parent compound, noscapine. Noscapinoids inhibit the proliferation of cancer cells that are resistant to paclitaxel and epothilone. Noscapine also potentiated the anticancer activity of doxorubicin in a synergistic manner against triple negative breast cancer (TNBC). However, physicochemical and pharmacokinetic (ED50˜300-600 mg/kg bodyweight) limitations of noscapine present hurdle in development of commercial anticancer formulations. Therefore, objectives of the present review are to summarize the chemotherapeutic potential of noscapine and implications of nanoscale based drug delivery systems in enhancing the therapeutic efficacy of noscapine in cancer cells. We have constructed noscapine-enveloped gelatin nanoparticles, NPs and poly (ethylene glycol) grafted gelatin NPs as well as inclusion complex of noscapine in β-cyclodextrin (β-CD) and evaluated their physicochemical characteristics. The Fe3O4 NPs were also used to incorporate noscapine in its polymeric nanomatrix system where molecular weight of the polymer governed the encapsulation efficiency of drug. The enhanced noscapine delivery using μPAR-targeted optical-MR imaging trackable NPs offer a great potential for image directed targeted delivery of noscapine. Human Serum Albumin NPs (150-300 nm) as efficient noscapine drug delivery systems have also been developed for potential use in breast cancer.

Noscapine, the tubulin-binding anticancer agent, when administered orally, requires high ED(50) (300-600 mg/kg), whereas intravenous administration (10 mg/kg) results in rapid elimination of the drug with a half-life of 0.39 h. Hence, the development of long-circulating injectable nanoparticles can be an interesting option for designing a viable formulation of noscapine for anticancer activity. Noscapine-enveloped gelatin nanoparticles and poly(ethylene glycol)-grafted gelatin nanoparticles were constructed and characterized. Data indicate that smooth and spherical shaped nanoparticles of 127 ± 15 nm were engineered with maximum entrapment efficiency of 65.32 ± 3.81%. Circular dichroism confirms that nanocoacervates retained the α-helical content of gelatin in ethanol whereas acetone favored the formation of a random coil. Moreover, the Fourier transform infrared and powder X-ray diffraction pattern prevents any significant change in the noscapine-loaded gelatin nanoparticles in comparison with individual components. In-vitro release kinetic data suggest a first-order release of noscapine (85.1%) from gelatin nanoparticles with a release rate constant of 7.611×10(-3). It is to be noted that there is a 1.43-fold increase in the area under the curve up to the last sampling point for the noscapine-loaded poly(ethylene glycol)-grafted gelatin nanoparticles over the noscapine-loaded gelatin nanoparticles and a 13.09-fold increase over noscapine. Cytotoxicity analysis of the MCF-7 cell line indicated that the IC(50) value of the noscapine-loaded poly(ethylene glycol)-grafted gelatin nanoparticles was equivalent to 20.8 μmol/l, which was significantly (P<0.05) lower than the IC(50) value of the noscapine-loaded gelatin nanoparticles (26.3 μmol/l) and noscapine (40.5 μmol/l).Noscapine-loaded poly(ethylene glycol)-grafted gelatin nanoparticles can be developed as a promising therapeutic agent for the management of breast cancer.

siRNA are a rapidly emerging class of new therapeutic molecules for the treatment of inherited and acquired diseases. However, poor cellular uptake and instability in physiological conditions limits its therapeutic potential, hence a need to develop a delivery system that can protect and efficiently transport siRNA to the target cells has arisen. Nanoparticles have been proposed as suitable delivery vectors with reduced cytotoxicity and enhanced efficacy. These delivery vectors form condensed complexes with siRNA which, in turn, provides protection to siRNA against enzymatic degradation and further leads to tissue and cellular targeting. Nanoparticles derived from polymers, such as chitosan and polyethylenimine have found numerous applications owing to ease of manipulation, high stability, low cost and high gene carrying capability. This article focuses on various aspects of nanomedicine based siRNA delivery with emphasis on targeted delivery to tumors.

Degradation of mRNA by RNA interference is one of the most powerful and specific mechanism for gene silencing. Owing to this property, siRNAs are emerging as promising therapeutic agents for the treatment of inherited and acquired diseases, as well as research tools for the elucidation of gene function in both health and disease. Here we have explored the potential of polyethylenimine (PEI) to deliver siRNA to mammalian cells. Nanoparticles of PEI were prepared by acylating PEI with propionic anhydride followed by cross-linking with polyethylene glycol-bis(phosphate). The nanoparticles size as revealed by DLS studies was found to be approximately 110 nm and AFM investigations showed spherical and compact complexes with an average size of 100 nm. For electro-neutralization of negative charge of siRNA higher amount of nanoparticles was required as compared to native PEI. The siRNA delivery efficiency of nanoparticles was assessed by using siRNA against gene coding for green fluorescent protein (GFP). The gene silencing efficiency of PEI nanoparticles was found to be comparable to commercially available transfecting agent Lipofectin but with reduced cytotoxicity.

Polyethylenimine (750 kDa) has been derivatized to influence the proton sponge mechanism and hydrophobic-hydrophilic balance. The polymer was acylated using acid anhydrides of varying carbon chain length, followed by cross-linking with PEG-bis-P to form compact nanoparticles. The chemical linkages in the particles were characterized by FTIR and NMR spectroscopy. The hydrodynamic diameter of nanoparticles was found to be in the range of 83.5-124 nm. AFM imaging of native and DNA-loaded nanoparticles revealed highly compact and spherical shape. The positive surface charge on particles decreased with the increase in percentage of acylation and also on complexing with DNA. The buffering capacity of PEI was reduced considerably on preparing acylated nanoparticles. The nanoparticles formed stable complexes with DNA and higher weight ratios were required for formation of electro-neutral complexes. Further, these nanoparticles were investigated for their gene delivery efficacy on COS-1 cells. It was found that acylated PEI nanoparticles were 5-12-fold more efficient transfecting agents as compared to native PEI (750 kDa) and commercially available transfecting agent lipofectin. The MTT colorimetric assay revealed of considerable reduction in toxicity of acylated PEI nanoparticles as compared PEI. Of all the systems prepared, nanoparticles with 30% acylation using propionic anhydride were found to be the most efficient in in vitro transfection.

Silver nanoparticles were sputter deposited through self organized hexagonally ordered porous anodic alumina templates that were fabricated using a two-step anodization process. The average pore diameter of the template was 90 nm and the interpore spacing was 120 nm. Atomic force microscope studies of the sputter-deposited silver nanoparticle array on a Si substrate indicate an approximate replication of the porous anodic alumina mask. The nature of the deposition depends strongly on the process parameters such as sputtering voltage, ambient pressure and substrate temperature. We report a detailed study of the sputtering conditions that lead to an optimal deposition through the template.

Polymeric nanoparticles of AADG cross-linked with MBA encapsulating water soluble macromolecules such as FITC-Dextran have been prepared in the reverse micellar system. The particles obtained were of >85nm in diameter which were highly monodisperse. An optically clear solution was obtained on redispersing these nanoparticles in aqueous buffer. Size and morphology of the particles remains the same on re-dispersing the lyophilized powder of these nanoparticles in aqueous buffer. The size dependency of the particles on the monomer and surfactant concentration was observed. The average size of the nanoparticles as obtained from DLS studies ranges from 74 to 114nm in case 0.06M AOT and 62-104nm in case of 0.1M AOT concentration. FITC-Dextran was entrapped into nanoparticles with high efficiency (>70%). The pH dependent release of the entrapped molecules from these nanoparticles was also studied. At pH 5.0 solution, approximately 43% of FITC-Dx was released and at pH 7.4 it was about 70%.

Polyallylamine (PAA), a less investigated polycationic polymer along with polyanionic dextran sulfate (DS) has been complexed with DNA into self assembling PAA-DS-DNA complexes with zinc as stabilizing agent. The complexes prepared were characterized by dynamic light scattering and atomic force microscopy and found to have average hydrodynamic diameter of 150nm with polydispersity below 0.2, i.e. nanoplexes with narrow size distribution. As expected, the zeta potential values increased with the increase in the PAA in the nanoplexes. Further, PAA-DS-DNA nanoplexes were investigated for in vitro transfecting efficacy on HEK 293 cells. The nanoplexes were found to have better gene transfer efficacy compared to the DNA-PAA complex and commercially available transfecting agent lipofectin. The cytotoxicity was also decreased considerably as revealed by MTT colorimetric assay. The nanoplexes prepared with PAA to DS ratio of 2 were found to be most efficient transfecting agent.

Nanocomposite thin films of fullerene C60 containing Ag nanoparticles (NPs) were synthesized by thermal codeposition. The surface plasmon resonance (SPR) band of the nanocomposite film was observed in the region 450–550 nm, showing a large redshift with increasing metal concentration. This is explained by the Maxwell–Garnett effective medium theory considering the absorbing nature of fullerene C60. The C60–Ag nanocomposite thin film with lowest Ag concentration was annealed at increasing temperatures in neutral atmosphere. The SPR band showed first a small redshift after annealing at small temperature then progressive blueshift at higher temperature. This behavior of SPR is explained by the increased particle–particle interaction due to the compaction of the fullerene C60 film upon annealing at low temperature and the transformation of fullerene C60 matrix into amorphous carbon at higher temperature. Rutherford backscattering spectrometry and transmission electron microscopy were used to quantify Ag metal content and the microstructural evolution of Ag NPs in the nanocomposite films, respectively. Thermal induced structural transformations of fullerene C60 molecules of host matrix were investigated by Raman spectroscopy. [ABSTRACT FROM AUTHOR]

For the first time commercially obtained TiO 2 nanoparticles (NPs) were successfully encapsulated in zeolitic imidazole framework-8 (ZIF-8) through in situ incorporation. Synthesized TiO 2 @ZIF-8 composite was found to have high thermal stability and retained same hexagonal morphology of ZIF-8 as supported by powder crystal X-ray diffraction pattern. The composite (TiO 2 @ZIF-8) has higher photo-catalytic activity than TiO 2 NPs for the degradation of methylene blue and rhodamine-B, and it retained high catalytic efficiency even after the fifth catalytic cycle. This study suggests a promising approach towards the heterogeneous photo-catalytic dye degradation technique using ZIF-8 as the catalytic host for long known photo-catalyst TiO 2 NPs. [ABSTRACT FROM AUTHOR]

Thermally switched cationic exchange in magnetically ordered ZnFeO (ZFO) nanoparticles synthesized via the coprecipitation route has been studied. The ZFO sample synthesized at 343 K and further annealed at 573 K is devoid of any X-ray diffraction (XRD) peak. However, the samples annealed at temperatures 673-973 K show clear XRD peaks indexed to a cubic spinel ferrite. The average crystallite sizes of the ZFO were calculated using Scherrer's formula and found in the range of 10-16 nm. The lattice parameter of ZFO nanoparticles increased from 8.212 to 8.524 nm as the annealing temperature was raised from 673 to 973 K. Despite the fact that ZFO is antiferromagnetic in bulk, the ZFO nanoparticles annealed at temperatures ≥673 K show a magnetic hysteresis loop. The value of spontaneous magnetization has been decreased from 22 to 16 emu/gm with an increase in the annealing temperature. The electron spin resonance spectra show a single resonance peak with linewidth ranging from 147 to 243 Oe. [ABSTRACT FROM AUTHOR]

Sleeping sickness (causal agent, Trypanosoma sp. parasite) causes huge morbidity and mortality in Africa (both human and livestock) in particular and zoo animals worldwide. Three of the four currently approved drugs (Pentamidine, Melarsoprol, Eflornithine, and Nifurtimox) were developed over 50 years ago. Current therapies are unsatisfactory due to unacceptable level of side effects. Pentamidine, an aromatic diamidine, safest so far, inhibits mitochondrial enzymes. Furthermore, it is effective only in early stages of infections and not on the later stage. Melarsoprol, practically insoluble in water, is very toxic and it is given intravenously (i.v.) for later stage infections only. Other drugs like eflornithine and nitfurtimox are also unsatisfactory for various reasons. Human serum derived high-density lipoprotein (HDL; not mouse or any other mammalian HDL) shows trypanolytic effect in vitro and in vivo on T. brucei. But the mechanism of action of human HDL is far from clear. In the absence of novel drug leads, nanodrugs might be valid options as nanoparticles show better accessibility to cells, supramolecular interactions due to enormous increase in surface area to volume ratio, altered partition coefficient, etc. Surface-modified hydrophobic microsilica (FS), mixture of micro- and nanosilica (Dsethvasan) and nanosilica (AL) were characterized by UV-Vis, DLS, SEM, EDAX, AFM, and XRD. Trypanosoma evansi collected from infected horses were injected in mice. Control infected mouse (n = 30) showed 100% mortality within 72±24 h of injection. Dsethvasan-treated mice (n = 30) survived for 192±24 h. FS-treated mice (n = 30) survived for 120±24 h but the AL-treated mice (n = 30) died within 72±24 h of inoculation like infected control. Hydrophobic Dsethvasan which consists of pure amorphous forms of micro- and nanosilica works better than FS (AL is not at all effective). Therefore, micro- and nanomixture of amorphous silica is best suited for treating Trypanosoma infection in mice. The possible role of ratio of higher to lower size class has been discussed. [ABSTRACT FROM AUTHOR]

Physical vapor deposition techniques such as sputtering and laser ablation – which are very commonly used in thin film technology – appear to hold much promise for the synthesis of nanocrystalline thin films as well as loosely aggregated nanoparticles. We present a systematic study of the process parameters that facilitate the growth of nanocrystalline metals and oxides. The systems studied include TiO[sub 2] , ZnO, γ-Al[sub 2] O[sub 3] , Cu[sub 2] O, Ag and Cu. The mean particle size and crystallographic orientation are influenced mainly by the sputtering power, the substrate temperature and the nature, pressure and flow rate of the sputtering gas. In general, nanocrystalline thin films were formed at or close to 300 K, while loosely adhering nanoparticles were deposited at lower temperatures. [ABSTRACT FROM AUTHOR]

In this study, the effect of swift heavy ion irradiation on the magnetic properties of the Pd nanoparticles has been investigated. Structural investigations along with superconducting quantum interface device measurements show that ferromagnetic properties of the Pd nanoparticles are due to the deviation of their electronic structure from that of bulk. The electronic structure is further modified due to the creation of defects on ion irradiation, which results in 20 times increase in the saturation magnetization. The present study establishes that the defect induced modification of Pd 4d electronic structure is responsible for the ferromagnetic properties of the Pd nanoparticles. [ABSTRACT FROM AUTHOR]

Films of C70 fullerene containing silver nanoparticles were synthesized by thermal codeposition. Optical absorption studies revealed that surface plasmon resonance of Ag nanoparticles occurs at unusually large wavelength, which showed a regular redshift from 521 to 581 nm with increase in metal content from 4.5% to 28%. It is explained by the Maxwell–Garnett theory considering the absorbing nature of fullerene matrix. Rutherford backscattering and transmission electron microscopy were performed to quantify metal content and the particle size, respectively. A better detection of low intensity vibrational modes of C70 in Raman scattering is observed due to surface enhanced Raman scattering. [ABSTRACT FROM AUTHOR]

We study the optical and microstructural properties of silver/amorphous carbon (Ag/a-C) nanocomposite thin film and its modification induced by swift heavy ion irradiation. Ag nanoparticles (NPs) embedded in a-C matrix were synthesized by co-sputtering of Ag and graphite by 1.5keV neutral Ar atom beam. These Ag NPs were irradiated by 120MeV Ag ions at different fluences ranging from 1×1012 to 3×1013 ions/cm2. Optical absorption studies revealed that surface plasmon resonance of Ag NPs in pristine film occurs at a wavelength of ~430nm and it shows a blue shift (~26nm) with increasing ion fluence up to 3×1013 ions/cm2. Transmission electron microscopy and Rutherford backscattering spectroscopy were used to quantify particle size and metal atomic fraction, respectively, in the nanocomposite films. The growth of Ag NPs with bi-model distribution at a fluence of 3×1013 ions/cm2 was observed with ion irradiation. Raman spectroscopy was used to investigate the effect of heavy ion irradiation on carbon matrix. The blue shift in plasmonic wavelength is explained in terms of increase in sp2 content in carbon matrix by heavy ion irradiation due to thermal energy deposition which leads to a decrease in dielectric properties of the matrix. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we study the optical and microstructural properties of silver–fullerene C60 nanocomposite and their modifications induced by swift heavy ion irradiation. Silver nanoparticles embedded in fullerene C60 matrix were synthesized by co-deposition of silver and fullerene C60 by thermal evaporation. The nanocomposite thin films were irradiated by 120MeV Ag ions at different fluences ranging from 1×1012 to 3×1013 ions/cm2. Optical absorption studies revealed that the surface plasmon resonance of Ag nanoparticles showed a blue shift of ∼49nm with increasing ion fluence up to 3×1013 ions/cm2. Transmission electron microscopy and Rutherford backscattering spectroscopy were used to quantify particle size and metal atomic fraction in the nanocomposite film. Growth of Ag nanoparticles was observed with increasing ion fluence. Raman spectroscopy was used to understand the effect of heavy ion irradiation on fullerene matrix. The blue shift in plasmonic wavelength is explained by the transformation of fullerene C60 matrix into amorphous carbon. [Copyright &y& Elsevier]

We investigated exchange bias as a function of temperature in nanoparticles of ferrimagnetic normal spinel NiCr2O4. The studied bulk compound exhibits ferrimagnetic and canted antiferromagnetic ordering at 68K and 30K respectively. Sample characterization was carried out using X-Ray, Field Emission Scanning Electron Microscope (FE-SEM) and Transmission Electron Microscope (TEM) measurements. Magnetization measurements as a function of temperature has revealed interesting features. Magnetic isotherms of bulk and nanoparticle sample were also investigated at different temperatures. It was found that in nanoparticles, with decrease in temperature, exchange bias first increases, attains maximum value and then subsequently decreases. We argue that in nanoparticles, the higher exchange bias at 68K is because of coexistence of ferrimagnetic and surface spin effect. However, the presence of glassy spin state may be the reason for decreasing exchange bias effect below Tc down to 5K. [ABSTRACT FROM AUTHOR]