Immunological characterization of chitosan adjuvanted outer membrane proteins of Salmonella enterica serovar Typhi as multi-epitope typhoid vaccine candidate.

BACKGROUND: Outer membrane proteins (OMPs) of Gram-negative bacteria have been known as potential vaccine targets due to their antigenic properties and host specificity. Here, we focused on the exploration of the immunogenic potential and protective efficacy of total OMPs of Salmonella enterica serovar Typhi due to their multi epitope properties, adjuvanted with nanoporous chitosan particles (NPCPs). The study was designed to extrapolate an effective, low cost prophylactic approach for typhoid fever being getting uncontrolled in Pakistan due to emergence of extensively drug resistant (XDR) strains. METHODS & RESULTS: The OMPs of two S. Typhi variants (with and without Vi capsule) alone and with nanoporous chitosan particles as adjuvant were comparatively analyzed for immunogenic potential in mice. Adaptive immunity was evaluated by ELISA and relative quantification of cytokine gene expression (IL4, IL6, IL9, IL17, IL10, TNF, INF and PPIA as house keeping gene) using RT-qPCR. Statistical analysis was done using Welch's test. The protection was recorded by challenging the immunized mice with 50% ×LD50 of S. Typhi. The Vi + ve-OMPs of S. Typhi showed the most promising results by ELISA and significantly high expression of IL-6, IL-10 and IL-17 and 92.5% protective efficacy with no detectable side effects. CONCLUSION: We can conclude that the OMPs of Vi + ve S. Typhi are the most promising candidates for future typhoid vaccines because of cost effective preparation without expensive purification steps and multi-epitope properties. Chitosan adjuvant may have applications for oral protein based vaccines but found less effective in injectable preparations.

Fluorescent organic nanoparticles (FONs) as convenient probes for metal ion detection in aqueous medium.

Recently, water contamination caused by metal ions has become one of the most serious problems as it has caused several deaths and socioeconomic problems around the world. Hence, the fast and accurate detection of metal ions in aqueous media has become the most important area of research; from time to time, new probes have been designed for this purpose. Among the previously reported sensors, probes based on fluorescent organic nanoparticles (FONs) have been gaining tremendous attention due to their ease of preparation/fabrication, synthetic diversity according to targeted metal ions, quick response, high selectivity toward different analytes at lower concentrations, tenable optical properties, and less toxicity. This review comprises two main sections, wherein we have tried to summarize the key progresses made in this field. The first section summarizes the literature dealing with FON-based chemosensors, which are used for the detection of transition metal ions of silver, copper, chromium, cadmium, mercury, iron, and zinc. The second section focuses on FON-based chemosensors that have been used for the detection of main group metal ions, namely, cesium, aluminum, strontium, lithium, and tin. Further, this review provides an adequate amount of information about the mechanism of metal ion sensing with FONs. It is expected that this review can provide sufficient information about this area of research and will be useful in fruitful progress in this field in the future.

Random mutagenesis of super Koji (Aspergillus oryzae): improvement in production and thermal stability of α-amylases for maltose syrup production.

BACKGROUND: Alpha-amylases hydrolyze 1,4 α-glycosidic bonds of starch and produce malto-oligosaccharides. It is an important enzyme generally applied in textile, food and brewing industries. Enhancement in thermal stability and productivity of enzymes are the two most sought after properties for industrial use. The Aspergillus oryzae (Koji) has Generally Recognized as Safe (GRAS) status and safe for use in food industry. Hence, Koji strain's development for the screening of potent mutants, hyper producer of thermostable α-amylases, with desired attributes is the need of the time. RESULTS: A process has been developed to improve super Koji (A. oryzae cmc1) strain through γ-rays treatment. The doses i.e. 0.60, 0.80, 1.00, 1.20 & 1.40 KGy gave more than 3.0 log kill. Initially, 52 Koji mutants resistant to 1% (w/v) Triton X-100 were selected. 2nd screening was based on α-amylases hyper production and 23 mutants were sorted out by measuring clearing zones index (CI). Afterwards nine potent mutants, resistant to 2-deoxy D-glucose, were screened based on CI. These were further analyzed for thermal stability and productivity of α-amylase under submerged conditions. The mutants' M-80(10), M-100(6) & M-120(5) gave about four fold increases in α-amylases productivity. The half life of M-100(6) α-amylase at 55 °C was 52 min and was highest among the mutants. Liquid Chromatography-Mass Spectrometry (LC-MS) analysis confirmed that mutants did not produce aflatoxins. Field Emission Scanning Electron Microscopy (FESEM) of Koji mycelia depicted that exposure to gamma rays increased rigidity of the mycelium. The potent Koji mutant M-100(6) was grown on soluble starch in 10L fermenter and produced 40.0 IU ml-1 of α-amylases with specific activity of 2461 IU mg-1 protein. Growth kinetic parameters were: µ = Specific growth rate= 0.069 h-1, td = Biomass doubling time= 10.0 h, Yp/x = Product yield coefficient with respect to cell mass = 482 U g-1; qp= Specific rate of product formation= 33.29 U g-1 h-1. CONCLUSION: It was concluded that the developed five step screening process has great potential to generate potent mutants for the hyper production of thermostable enzymes through γ-rays mediated physical mutagenesis. The developed thermostable α-amylases of super Koji mutantM-100(6) has immense potential for application in saccharification process for maltose syrup production. Moreover, the developed five step strain's development process may be used for the simultaneous improvement in productivity and thermal stability of other microbial enzymes.

Molecularly imprinted porous beads for the selective removal of copper ions.

In the present work, novel molecularly imprinted polymer porous beads for the selective separation of copper ions have been synthesized by combining two material-structuring techniques, namely, molecular imprinting and oil-in-water-in-oil emulsion polymerization. This method produces monodisperse spherical beads with an average diameter of ∼2-3 mm, in contrast to adsorbents produced in the traditional way of grinding and sieving. Field-emission scanning electron microscopy indicates that the beads are porous in nature with interconnected pores of about 25-50 µm. Brunner-Emmett-Teller analysis shows that the ion-imprinted beads possess a high surface area (8.05 m(2) /g), and the total pore volume is determined to be 0.00823 cm(3) /g. As a result of the highly porous nature and ion-imprinting, the beads exhibit a superior adsorption capacity (84 mg/g) towards copper than the non-imprinted material (22 mg/g). Furthermore, selectivity studies indicate that imprinted beads show splendid recognizing ability, that is, nearly fourfold greater selective binding for Cu(2+) in comparison to the other bivalent ions such as Mn(2+) , Ni(2+) , Co(2+) , and Ca(2+) . The imprinted composite beads prepared in this study possess uniform porous morphology and may open up new possibilities for the selective removal of copper ions from waste water/contaminated matrices.

Surface engineering of chitosan nanosystems and the impact of functionalized groups on the permeability of model drug across intestinal tissue.

Surface attributes of nanocarriers are crucial to determine their fate in the gastrointestinal (GI) tract. Herein, we have functionalized chitosan with biochemical moieties including rhamnolipid (RL), curcumin (Cur) and mannose (M). FTIR spectra of functionalized chitosan nanocarriers (FCNCs) demonstrated successful conjugation of M, Cur and RL. The functional moieties influenced the entrapment of model drug i.e., coumarin-6 (C6) in FCNCs with payload-hosting and non-leaching behavior i.e., >91 ± 2.5 % with negligible cumulative release of <2 % for 5 h in KREB, which was further verified in the simulated gastric and intestinal fluids. Consequently, substantial difference in the size and zeta potential was observed for FCNCs with different biochemical moieties. Scanning electron microscopy and atomic force microscopy of FCNCs displayed well-dispersed and spherical morphology. In addition, in vitro cytotoxicity results of FCNCs confirmed their hemocompatibility. In the ex-vivo rat intestinal models, FCNCs displayed a time-dependent-phenomenon in cellular-uptake and adherence. However, apparent-permeability-coefficient and flux values were in the order of C6-RL-FCNCs > C6-M-FCNCs > C6-Cur-FCNCs = C6-CNCs > Free-C6. Furthermore, the transepithelial electrical resistance revealed the FCNCs mediated recovery of membrane-integrity with reversible tight junctions opening. Thus, FCNCs have the potential to overcome the poor solubility and/or permeability issues of active pharmaceutical ingredients and transform the impact of functionalized-nanomedicines in the biomedical industry.

Ba2-xHoxSr2-yNiyFe12O22 and its composite with MXene: synthesis, characterization and enhanced visible light mediated photocatalytic activity for colored dye and pesticide.

The rapid recombination of charges of photogenerated electrons and holes severely limits single semiconductor photocatalytic applications. In this study, a simple and facile sol-gel approach was used to synthesize Ba2-xHoxSr2-yNiyFe12O22 (x = 0, 0.1 and y = 0, 0.5). The composite of holmium-nickel doped barium-strontium ferrite with MXene (Ba1.9Ho0.1Sr1.5Ni0.5Fe12O22@MXene) was synthesized by ultrasonication method. These synthesized samples were subsequently used to photodegrade rhodamine B (RhB) and pendimethalin under visible light illumination. The results of the experiments demonstrated that MXene, as a cocatalyst, considerably reduces the rate of recombination of charges and broadens absorption of visible light by providing increased surface functional groups to improve the photocatalytic activity of synthesized samples. MXene is thermally stable, have high electrical conductivity, have adjustable bandgap, and hydrophilic in nature. The optimized Ba1.9Ho0.1Sr1.5Ni0.5Fe12O22@MXene composite demonstrated an excellent photocatalytic rate by degrading 78.88% RhB and 75.59% pendimethalin in 140 minutes. Moreover, the scavenging experiment revealed that photogenerated electrons and holes were the primary active species involved in RhB and pendimethalin photodegradation, respectively. Ba1.9Ho0.1Sr1.5Ni0.5Fe12O22@MXene showed increased photocatalytic behavior because it has increased surface area which decreases rate of recombination of electron and hole pair, hence photocatalytic activity increases. It is observed that Ba1.9Ho0.1Sr1.5Ni0.5Fe12O22@MXene has potential application in photocatalytic degradation of harmful pollutants.

Nanogold morphologies with the same surface chemistry provoke a different innate immune response: An in-vitro and in-vivo study.

Gold nanomaterials (GNMs) have unique optical properties with less antigenicity, and their physicochemical properties have strong relation with an immunological response at bio-interface including antigenicity. An interpretation of this correlation would significantly impact on the clinical and theranostic applications of GNMs. Herein, we studied the effect of GNMs morphology on the cytotoxicity (in-vitro), innate immune responses, hepatotoxicity, and nephrotoxicity (in-vivo studies) using gold nano-cups (GNCs), porous gold nanospheres (PGNSs) and solid gold nano particles (SGNPs) coated with the same ligand to ensure similar surface chemistry. The cytotoxicity was assessed via sulfo-rhodamine B (SRB) assay, and the cytotoxicity data showed that morphological features at nanoscale dimensions like surface roughness and hollowness etc. have a significant impact on cellular viability. The biochemical and histopathological study of liver and kidney tissues also showed that all GNMs did not show any toxicity even at high concentration (100 µL). The relative quantification of cytokine gene expression of TNF-α, IFN-γ, IL-4, 1L-6, and 1L-17 (against each morphology) was checked after in-vivo activation in mice. Among the different nanogold morphologies, PVP stabilized GNCs (PVP-GNCs) showed the highest release of pro-inflammatory cytokines, which might be due to their high surface energy and large surface area for exposure as compared to other nanogold morphologies studied. The pro-inflammatory cytokine release could be suppressed by coating with some anti-inflammatory polymer, i.e., inulin. The in-vitro results of pro-inflammatory (TNF-α, IL-1) cytokines also suggested that all GNMs may induce activation of macrophages and Th1 immune response. The in-vivo activation results showed a decrease in mRNA expression of the cytokines (TNF-α, IFN-γ, IL-4, 1L-6 and 1L-17). Based on these findings, we proposed that the shape and morphology of GNMs control their immune response at nano-bio interface, and it must be considered while designing their role for different biomedical applications like immuno-stimulation and bio-imaging.

Synthesis and Characterization of Antibiotic-Loaded Biodegradable Citrate Functionalized Mesoporous Hydroxyapatite Nanocarriers as an Alternative Treatment for Bone Infections.

The continuing growth of bacterial resistance makes the top challenge for the healthcare system especially in bone-infections treatment. Current estimates reveal that in 2050 the death ratio caused by bacterial infections can be higher than cancer. The aim of this study is to provide an alternative to currently available bone-infection treatments. Here we designed mesoporous hydroxyapatite nanocarriers functionalized with citrate (Ctr-mpHANCs). Amoxicillin (AMX) is used as a model drug to load in Ctr-mpHANCs, and the drug loading was more than 90% due to the porous nature of nanocarriers. Scanning electron microscopy shows the roughly spherical morphology of nanocarriers, and the DLS study showed the approximate size of 92 nm. The Brunauer-Emmett-Teller (BET) specific surface area and pore diameter was found to be about 182.35 m2/g and 4.2 nm, respectively. We noticed that almost 100% of the drug is released from the AMX loaded Ctr-mpHANCs (AMX@Ctr-mpHANCs) in a pH-dependent manner within 3 d and 5 d at pH 2.0 and 4.5, respectively. The sustained drug release behaviour was observed for 15 d at pH 7.4 and no RBCs hemolysis by AMX@Ctr-mpHANCs. The broth dilution and colony forming unit (CFU) assays were used to determine the antimicrobial potential of AMX@Ctr-mpHANCs. It was observed in both studies that AMX@Ctr-mpHANCs showed a significant reduction in the bacterial growth of S. aureus, E. coli, and P. aeruginosa as compared to Ctr-mpHANCs with no bacteria-killing. Thus, we proposed that Ctr-mpHANCs can be used as a drug carrier and a treatment option for bone infections caused by bacteria.

Gut-Thyroid axis: How gut microbial dysbiosis associated with euthyroid thyroid cancer.

Thyroid cancer in humans has a fast-growing prevalence, with the most common lethal endocrine malignancy for unknown reasons. The current study was aimed to perform qualitative and quantitative investigation and characterization of the gut bacterial composition of euthyroid thyroid cancer patients. The fecal samples were collected from sixteen euthyroid thyroid cancer patients and ten from healthy subjects. The PCR-DGGE was conducted by targetting the V3 region of 16S rRNA gene, as well as real-time PCR for Bacteroides vulgatus, E.coli Bifidobacterium, Clostridium leptum and Lactobacillus were carried. High-throughput sequencing of V3+V4 region of 16S rRNA gene was performed on Hiseq 2500 platform on 20 (10 healthy & 10 diseased subjects) randomly selected fecal samples. The richness indices and comparative diversity analysis showed significant gut microbial modification in euthyroid thyroid cancer than control. At phylum level, there was significant enrichment of Firmicutes, Verrucomicrobia, while a significant decrease in Bacteroidetes was detected in the experimental group. At family statistics, significant high levels of Ruminococcaceae and Verrucomicrobiaceae, while the significant lower abundance of Bacteroidaceae, Prevotellaceae, Porphyromonadaceae, and Alcaligenaceae was after observed. It also found that the significantly raised level of Escherichia-Shigella, Akkermansia [Eubacterium]_coprostanoligenes, Dorea, Subdoligranulum, and Ruminococcus_2 genera, while significantly lowered genera of the patient group were Prevotella_9, Bacteroides and Klebsiella. The species-level gut microbial composition showed a significantly raised level of Escherichia coli in euthyroid thyroid cancer. Thus, this study reveals that euthyroid thyroid cancer patients have significant gut microbial dysbiosis. Moreover, Statistics (P<0.05) of each gut microbial taxa were significantly changed in euthyroid thyroid cancer patients. Therefore, the current study may propose new approaches to understanding thyroid cancer patients' disease pathways, mechanisms, and treatment.

Supramolecular lipid nanoparticles as delivery carriers for non-invasive cancer theranostics.

Nanotheranostics is an emerging frontier of personalized medicine research particularly for cancer, which is the second leading cause of death. Supramolecular aspects in theranostics are quite allured to achieve more regulation and controlled features. Supramolecular nanotheranostics architecture is focused on engineering of modular supramolecular assemblies benefitting from their mutable and stimuli-responsive properties which confer an ultimate potential for the fabrication of unified innovative nanomedicines with controlled features. Amalgamation of supramolecular approaches to nano-based features further equip the potential of designing novel approaches to overcome limitations seen by the conventional theranostic strategies, for curing even the lethal diseases and endowing personalized therapeutics with optimistic prognosis, endorsing their clinical translation. Among many potential nanocarriers for theranostics, lipid nanoparticles (LNPs) have shown various promising advances in theranostics and their formulation can be tailored for several applications. Despite the great advancement in cancer nanotheranostics, there are still many challenges that need to be highlighted to fill the literature gap. For this purpose, herein, we have presented a systematic overview on the subject and proposed LNPs as the potential material to manage cancer via non-invasive approaches by highlighting the use of supramolecular approaches to make them robust for cancer theranostics. We have concluded the review by entailing the future perspectives of lipid nanotheranostics towards clinical translation.

Preparation and catalytic evaluation of Au/γ -Al2O3 nanoparticles for the conversion of 4-nitrophenol to 4-aminophenol by spectrophotometric method.

A set of catalysts having gold nanoparticles deposited on γ -Al2O3 ( Au/ γ -Al2O3) with lowest effective amount of gold content were prepared by successive impregnation and hydrogen reduction method. The structural features of prepared catalysts were analysed by X-ray diffraction (XRD), N2 physisorption, scanning electron microscopy (SEM), and Fourier transform infrared (FTIR). The catalytic activity was evaluated for the reduction of an organic pollutant 4-nitrophenol (4NP) to 4-aminophenol (4AP) by spectrophotometric analysis. Supported catalyst presented excellent catalytic ability to convert 4NP to 4AP in the presence of sodium borohydride (SBH) due to synergistic effect of Au NPs and mesoporous γ -Al2O3 support. The reduction reaction was also performed at a range of temperatures to calculate kinetic parameters. The development of highly stable Au/γ -Al2O3 catalysts with lowest noble metal content and recyclability made the process cost effective and may promote their applications in various fields including removal of organic pollutants in industrial waste water and high-temperature gas-phase reactions.

Synthesis of SPIONs-CNT Based Novel Nanocomposite for Effective Amperometric Sensing of First-Line Antituberculosis Drug Rifampicin.

It is necessary to study the possible interactions among various chemical surfaces and analytes before applying them to biological systems. We report the synthesis of carbon nanotubes-iron oxide (SPIONs-CNT) nanocomposite material by using lecithin stabilized superparamagnetic iron oxide nanoparticles (SPIONs) obtained by facile hydrothermal technique. Various characterizations of the obtained nanocomposite were carried out and electrochemical studies were performed further to study the interaction capabilities of the nanocomposite with anti-TB drug Rifampicin. Obtained results by cyclic voltammetric studies of SPIONs-CNT nanocomposite with limit of detection (LOD) of 1.178 µM showed the enhanced electrochemical sensitivity and selectivity of anti-tuberculosis (anti-TB) drug Rifampicin (RIF).

Chitosan-albumin based core shell-corona nano-antimicrobials to eradicate resistant gastric pathogen.

In this study, protein/polysaccharide core-shell-corona (PP-CSC) nano delivery systems (NDS) were prepared by using bovine serum albumin (BSA) and chitosan (CS). The potential of PP-CSC-NDS for increasing the stability and bio-accessibility of ε-poly-l-lysine (ε-PL) as effective therapy for gastric Helicobacter pylori was investigated. The presence of CS-shell increased the size (223 ±â€¯1.7 nm) of BSA-core as compared to BSA-shell on CS-core (191 ±â€¯2.6 nm). Conversely, encapsulation efficiency of ε-PL was reduced for C(B)NDS [CS-shell on BSA-core] to 73 ±â€¯1% than 82 ±â€¯2% for B(C)NDS [BSA-shell on CS-core] due to cationic nature of ε-PL. Scanning electron microscopy of PP-CSC-NDS displayed smooth and non-flocculated morphology. FTIR analyses verified that the electrostatic interactions, H-bonding, and hydrophobic effects were involved in PP-CSC formation. Zeta analyses revealed that the net charge depends on the corona layer and the encapsulated antimicrobials. Moreover, CS corona improved the antimicrobial potential, controlled release, mucoadhesion and stability of ε-PL loaded C(B)NDS in simulated gastric fluid due to inherent antimicrobial and mucoadhesive properties of CS polymer. In contrast, protein corona improved the penetration into bacterial biofilms for better eradiation of H. pylori. Thus, conjugated nano-systems with selected corona can improve the overall efficacy of antimicrobials to develop effective nano-therapeutics against gastric infections.

Low Power Single Laser Activated Synergistic Cancer Phototherapy Using Photosensitizer Functionalized Dual Plasmonic Photothermal Nanoagents.

Combination therapy, especially photodynamic/photothermal therapy (PDT/PTT), has shown promising applications in cancer therapy. However, sequential irradiation by two different laser sources and even the utilization of single high-power laser to induce either combined PDT/PTT or individual PTT will be subjected to prolonged treatment time, complicated treatment process, and potential skin burns. Thus, low power single laser activatable combined PDT/PTT is still a formidable challenge. Herein, we propose an effective strategy to achieve synergistic cancer phototherapy under low power single laser irradiation for short duration. By taking advantage of dual plasmonic PTT nanoagents (AuNRs/MoS2), a significant increase in temperature up to 60 °C with an overall photothermal conversion efficiency (PCE) of 68.8% was achieved within 5 min under very low power (0.2 W/cm2) NIR laser irradiation. The enhanced PCE and PTT performance is attributed to the synergistic plasmonic PTT effect (PPTT) of dual plasmonic nanoagents, promoting simultaneous release (85%) of electrostatically bonded indocyanine green (ICG) to induce PDT effects, offering simultaneous PDT/synergistic PPTT. Both in vitro and in vivo investigations reveal complete cell/tumor eradication, implying that simultaneous PDT/synergistic PPTT effects induced by AuNRs/MoS2-ICG are much superior over individual PDT or synergistic PPTT. Notably, synergistic PPTT induced by dual plasmonic nanoagents also demonstrates higher in vivo antitumor efficacy than either individual PDT or PTT agents. Taken together, under single laser activation with low power density, the proposed strategy of simultaneous PDT/synergistic PPTT effectively reduces the treatment time, achieves high therapeutic index, and offers safe treatment option, which may serve as a platform to develop safer and clinically translatable approaches for accelerating cancer therapeutics.

Hollow mesoporous hydroxyapatite nanostructures; smart nanocarriers with high drug loading and controlled releasing features.

We report the development of effective drug loaded nanocarriers to combat multidrug resistant infection especially in case of osteomyelitis. The hollow mesoporous hydroxyapatite nanoparticles (hmHANPs) and solid/non-hollow hydroxyapatite nanoparticles (sHANPs) were synthesized by core-shell and co-precipitation techniques respectively. High encapsulation of the drug (ciprofloxacin) was observed in hmHANPs as compared to sHANPs, which may be due to the hollow porous structure of hmHANPs. These nanoparticles were characterized by scanning electron microscope (FESEM), N2 adsorption/desorption, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Thermogravimetric analysis (TGA). Approximately 80% of the encapsulated drug was released at pH 4.5 within 5 days in case of hmHANPs while at pH 7.4, a sustained drug release profile was obtained and only 48.73% of the drug was released after 9 days. The results of kinetic drug release revealed that drug loaded hmHANPs showed fickian diffusion and anomalous drug diffusion mechanism at pH 4.5 and 7.4 respectively. Owing to their porous structure and high drug loading capacity, hmHANPs showed enhanced antibacterial activity against Staphylococcus aureus and Escherichia coli (drug resistant strains of osteomyelitis) in comparison to that with sHANPs. In addition, hmHANPs showed a pH sensitive drug release profile, high surface area (105.33 m2/g) with increased pore volume (0.533 cm3/g) and superior antimicrobial activity against osteomyelitis as compared to sHANPs.

Solid lipid nanoparticles for thermoresponsive targeting: evidence from spectrophotometry, electrochemical, and cytotoxicity studies.

Thermoresponsive drug delivery systems are designed for the controlled and targeted release of therapeutic payload. These systems exploit hyperthermic temperatures (>39°C), which may be applied by some external means or due to an encountered symptom in inflammatory diseases such as cancer and arthritis. The objective of this paper was to provide some solid evidence in support of the hypothesis that solid lipid nanoparticles (SLNs) can be used for thermoresponsive targeting by undergoing solid-liquid phase transition at their melting point (MP). Thermoresponsive lipid mixtures were prepared by mixing solid and liquid natural fatty acids, and their MP was measured by differential scanning calorimetry (DSC). SLNs (MP 39°C) containing 5-fluorouracil (5-FU) were synthesized by hot melt encapsulation method, and were found to have spherical shape (transmission electron microscopy studies), desirable size (<200 nm), and enhanced physicochemical stability (Fourier transform infrared spectroscopy analysis). We observed a sustained release pattern (22%-34%) at 37°C (5 hours). On the other hand, >90% drug was released at 39°C after 5 hours, suggesting that the SLNs show thermoresponsive drug release, thus confirming our hypothesis. Drug release from SLNs at 39°C was similar to oleic acid and linoleic acid nanoemulsions used in this study, which further confirmed that thermoresponsive drug release is due to solid-liquid phase transition. Next, a differential pulse voltammetry-based electrochemical chemical detection method was developed for quick and real-time analysis of 5-FU release, which also confirmed thermoresponsive drug release behavior of SLNs. Blank SLNs were found to be biocompatible with human gingival fibroblast cells, although 5-FU-loaded SLNs showed some cytotoxicity after 24 hours. 5-FU-loaded SLNs showed thermoresponsive cytotoxicity to breast cancer cells (MDA-MB-231) as cytotoxicity was higher at 39°C (cell viability 72%-78%) compared to 37°C (cell viability >90%) within 1 hour. In conclusion, this study presents SLNs as a safe, simple, and effective platform for thermoresponsive targeting.

Assessing manganese nanostructures based carbon nanotubes composite for the highly sensitive determination of vitamin C in pharmaceutical formulation.

This work is the first report describing the development of a novel three dimensional manganese nanostructures based carbon nanotubes (CNTs-Mn NPs) composite, for the determination of ascorbic acid (vitamin C) in pharmaceutical formulation. Carbon nanotubes (CNTs) were used as a conductive skeleton to anchor highly electrolytic manganese nanoparticles (Mn NPs), which were prepared by a hydrothermal method. Scanning electron microscopy and atomic force microscopy revealed the presence of Mn Nps of 20-25nm, anchored along the whole length of CNTs, in the form of patches having a diameter of 50-500nm. Fourier transform infrared spectroscopy confirmed the surface modification of CNTs by amine groups, whereas dynamic light scattering established the presence of positive charge on the prepared nanocomposite. The binding events were studied by monitoring cyclic voltammetry signals and the developed nanosensor exhibited highly sensitive response, demonstrating improved electrochemical activity towards ascorbic acid. Linear dependence of the peak current on the square root of scan rates (R2=0.9785), demonstrated that the oxidation of ascorbic acid by the designed nanostructures is a diffusion control mechanism. Furthermore, linear range was found to be 0.06-4.0×10-3M, and nanosensor displayed an excellent detection limit of 0.1µM (S/N=3). This developed nanosensor was successfully applied for the determination of vitamin C in pharmaceutical formulation. Besides, the results of the present study indicate that such a sensing platform may offer a different pathway to utilize manganese nanoparticles based CNTs composite for the determination of other bio-molecules as well.

Novel route synthesis of porous and solid gold nanoparticles for investigating their comparative performance as contrast agent in computed tomography scan and effect on liver and kidney function.

Gold nanoparticles (GNPs) with dimension in the range of 1-100 nm have a prominent role in a number of biomedical applications like imaging, drug delivery, and cancer therapy owing to their unique optical features and biocompatibility. In this work, we report a novel technique for the synthesis of two types of GNPs namely porous gold nanoparticles (PGNPs) and solid gold nanoparticles (SGNPs). PGNPs of size 35 nm were fabricated by reduction of gold (III) solution with lecithin followed by addition of L-ascorbic acid and tri-sodium citrate, whereas SGNPs with a dimension of 28 nm were prepared by reflux method using lecithin as a single reducing agent. Comparative studies using PGNPs (λmax 560 nm) and SGNPs (λmax 548 nm) were conducted for evaluating their use as a contrast agent. These studies reveled that in direct computed tomography scan, PGNPs exhibited brighter contrast (45 HU) than SGNPs (26 HU). To investigate the effect of PGNPs and SGNPs on the liver and kidney profile, male rabbits were intravenously injected with an equal dose of 1 mg/kg weight of PGNPs and SGNPs. The effect on biochemical parameters was evaluated 72 hours after intravenous (IV) injection including liver function profile, renal (kidney) function biomarker, random blood glucose value, and cholesterol level. During one comparison of contrast in CT scan, PGNPs showed significantly enhanced contrast in whole-rabbit and organ CT scan as compared to SGNPs 6 hours after injection. Our findings suggested that the novel PGNPs enhance CT scan image with higher efficacy as compared to SGNPs. The results showed that IV administration of synthesized PGNPs increases the levels of aspartate aminotransferase (AST), alkaline phosphate (ALP), serum creatinine, and blood glucose, whereas that of SGNPs increases the levels of AST, ALP, and blood glucose.

Development of Cefotaxime Impregnated Chitosan as Nano-antibiotics: De Novo Strategy to Combat Biofilm Forming Multi-drug Resistant Pathogens.

Frequent incidents of antibiotic-resistant biofilm forming pathogens in community-associated and hospital-acquired infections have become a global concern owing to failure of conventional therapies. Nano-antibiotics (NABs) are de novo tools to overcome the multi-drug resistant mechanisms employed by the superbugs. Inhibition of biofilm formation is one of those strategies to curb multi drug resistance phenomenon. In the current study, the anti-biofilm and antibacterial potential of newly synthesized cefotaxime loaded chitosan based NABs have been investigated. Both bare and cefotaxime loaded NABs were prepared by ionotropic gelation method. They were found carrying positive zeta potential of more than +50 mV, indicating highly stable nano-dispersion. Moreover, microscopic studies revealed their size as less than 100 nm. NABs were tested against clinical isolates of multi drug resistant Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and methicillin resistant Staphylococcus aureus and wherein they demonstrated broad-spectrum anti-biofilm and anti-pathogenic activity. Thus, in vitro synergistic action of cephalosporin drugs and chitosan polymer at nano-scale in contrast to free antibiotics can be an improved broad-spectrum strategy to thwart resistance mechanisms in both Gram-positive and Gram-negative resistant pathogens.