Bakht Ramin Shah

Quantum dots loaded nanogels for low cytotoxicity, pH-sensitive fluorescence, cell imaging and drug delivery

Nanogels (NGs) with drug tracking and delivery possess promising usage in clinical treatment. In this study, an available, low toxic and facile approach was developed to synthesize CdTe quantum dots loaded nanogels (QDs-NGs). The QDs-NGs retained the intrinsic pH sensitivity of the QDs with regard to the fluorescence intensity. The QDs-NGs were easily internalized by the cells as fluorescence probes, and acted as carriers for delivering methotrexate (MTX). The cellular uptake indicated that the QDs-NGs can protect QDs from decomposition in cytoplasm and retain the native fluorescence intensity. MTT assay demonstrated that the QDs-NGs greatly decreased the cytotoxicity of the QDs. The MTX loaded QDs-NGs exhibited slow release property in PBS buffer. Moreover, the MTX loaded QDs-NGs distinctly enhanced the availability of drug. The QDs-NGs are potential nanocarriers for the cell imaging and drug delivery.

Green-step assembly of low density lipoprotein/sodium carboxymethyl cellulose nanogels for facile loading and pH-dependent release of doxorubicin.

In this study, a simple and green approach was developed to produce a novel nanogel via self-assembly of low density lipoproteins (LDL) and sodium carboxymethyl cellulose (CMC), to efficiently deliver doxorubicin (DOX) to cancer cells. Under optimal conditions, the stable nanogels were of spherical shape with an average diameter of about 90 nm, PDI<0.3 and a zeta potential -35 mV. Furthermore, the cationic anticancer drug, doxorubicin (DOX) was effectively encapsulated into LDL/CMC nanogels with an exceptionally high encapsulation efficiency of ∼ 98%. The release of DOX from DOX-LDL/CMC nanogels was pH-dependent, and DOX was released at a quicker rate at pH 6.2 than at pH 7.4. Importantly, the DOX-LDL/CMC nanogels were shown to effectively kill cancer cells in vitro. The IC50 of the DOX-LDL/CMC nanogels in HeLa and HepG2 cells was approximately 2.45 and 1.72 times higher than that of free DOX. The slightly reduced antitumor efficacy was primarily due to the less cellular uptake of the DOX-LDL/CMC nanogels, which was confirmed by confocal laser scanning microscope (CLSM) and flow cytometry analysis. The high DOX payload and pH-dependent drug release rendered LDL/CMC nanogels as an efficient carrier for doxorubicin and possibly be used for other cationic drugs in different biomedical applications.

High intensity ultrasound modified ovalbumin: Structure, interface and gelation properties.

Influence of high intensity ultrasound (HIUS) on the structure and properties of ovalbumin (OVA) were investigated. It was found that the subunits and secondary structure of OVA did not change significantly with HIUS treatment from the electrophoretic patterns and circular dichroism (CD) spectrum. The amount of free sulfhydryl groups increased and intrinsic fluorescence spectra analysis indicated changes in the tertiary structure and partial unfold of OVA after sonication increased. Compared with the untreated OVA, HIUS treatment increased the emulsifying activity and foaming ability, and decreased interface tension (oil-water and air-water interface), which due to the increased surface hydrophobicity and decreased the surface net charge in OVA, while the emulsifying and foaming stability had no remarkable differences. The increased particle size may be attributed to formation of protein aggregates. Moreover, the gelation temperatures of HIUS-treated samples were higher than the untreated OVA according to the temperature sweep model rheology, and this effect was consistent with the increased in surface hydrophobicity for ultrasound treated OVA. These changes in functional properties of OVA would promote its application in food industry.

Bioaccessibility and antioxidant activity of curcumin after encapsulated by nano and Pickering emulsion based on chitosan-tripolyphosphate nanoparticles

In the current study the influence of different lipid-based formulations (Pickering and nanoemulsions) and their droplet size on curcumin encapsulation and bioaccessibility, as well as on its anti-oxidant activity was investigated. Oil-in-water Pickering emulsion stabilized by chitosan-tripolyphosphate (CS-TPP) nanoparticles and nanoemulsions containing an organic phase (Span80:Tween80), were prepared with either medium chain triglyceride (MCT) or corn oil as long chain triglyceride (LCT). An in vitro gastrointestinal (GIT) model consisting of mouth, gastric and intestinal phases was used to characterize the rate and extent of lipid phase digestion of the ingested samples. A centrifugation method determined fraction of curcumin released into mixed micelles after digestion (bioaccessibility). These findings showed that after subjecting to simulated GIT model, all the emulsion systems experienced a progressive increase in mean particle size, due to droplet flocculation and coalescence after digestion. Electrical charge (ζ) of particles was observed to become highly negative as they passed through GIT due to accumulation of anionic bile salts, phospholipids and free fatty acids at their interfaces. The rate and extent of lipid digestion and bioaccessibility of curcumin increased with decreasing mean droplet diameter (NMCT>NCO>PMCT>PCO). Finally, we showed that as compared to free curcumin, the encapsulated curcumin showed higher radical scavenging activity (RSA), which confirmed the protective effect of the emulsion systems on the antioxidant activity of curcumin.

Enhancement of physical stability and bioaccessibility of tangeretin by soy protein isolate addition

Soy protein isolate (SPI) was selected to fabricate supersaturated self-emulsifying nanoemulsions, aiming to enhance physical stability and bioaccessibility of hydrophobic tangeretin. Dissolution studies demonstrated that tangeretin had the highest solubility in Tween 80, followed by oil phase solutions, and polymer solutions. Supersaturated tangeretin in oil phases easily formed crystals. That metastable zone was found to vary with its initial concentrations. After encapsulation by nanoemulsions, the addition of glycerol compressed the retention amount of tangeretin from 76% to 53%, but benefited the transparency. Whereas, the combination of glycerol and SPI could not only maintain high-loading tangeretin (>85%), but also provide high transparency for nanoemulsions. When tangeretin concentration was 4.83mM, combination of 50% glycerol and 1% SPI could maintain around 88% tangeretin in the nanoemulsion within one month. Its bioaccessibility of different systems were at 60-65%. These findings can provide useful information for protein to be a potential precipitation inhibitor.

Development of Mag-FMBO in clay-reinforced KGM aerogels for arsenite removal

To seek high-efficient, convenient and robust methods to decontaminate water polluted by arsenite are critically in demand. Here, we developed a series of magnetic konjac glucomannan (KGM) aerogels as adsorbents for arsenite removal. These adsorbents were fabricated based on sodium montmorillonite (Na(+)-MMT) reinforced KGM matrix with magnetic Fe and Mn oxides (Mag-FMBO) inside. The obtained aerogels adsorbents were characterized by using compression test, thermo gravimetric analysis (TGA), vibrating sample magnetometer (VSM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The characteristic results showed that the composite aerogels possessed strong mechanical and magnetic property, excellent thermal characteristic and tunable pore structure. Batch adsorption tests were used to evaluate arsenite removal capacity. The adsorption results exhibited that the arsenite removal process was pH-dependent, followed a pseudo-second-order rate equation and Langmuir monolayer adsorption. The maximum arsenite uptake capacity of magnetic aerogels M1.5 reached 16.03mgg(-1) according to Langmuir isotherm at pH 7 and 323K. Besides, the magnetic composite aerogels can be repeatedly used after the treatment of regenerant (NaOH/NaCl/NaClO solution).

Fabrication and characterization of KGM-based FMBO-containing aerogels for removal of arsenite in aqueous solution

Hybrid materials were obtained by immobilizing Fe and Mn oxides (FMBO) into a konjac glucomannan (KGM) based aerogel matrix to remove arsenite from water. Composite adsorbents were prepared through a coupling sol–gel process with a suitable freeze-drying technique. The KGM aerogels were employed as the framework and FMBO as the coating materials. Scanning electron microscopy (SEM), thermo gravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) were used for the characterization of the hybrid aerogels. The adsorption of As(III) by the composite aerogels decreased with increasing pH. Isotherms were well predicted by Freundlich behavior, implying the heterogeneous nature of the As(III) adsorption. The maximum As(III) uptake capacity reached 30.33 mg g−1 at the FMBO/KGM ratio of 1.5 : 1 at pH 7 and 323 K. The effects of coexisting anions including Cl−, NO3−, SO42−, SiO32−, PO43− as well as natural organic matter, which possibly exist in natural water, on As(III) removal were also investigated. The hybrid adsorbents could be easily regenerated by using NaOH solution, exhibiting excellent practicability and reusability. Furthermore, XPS analysis of composite aerogels before and after the reaction confirmed the oxidation–sorption mechanism for As(III) removal. This research extends the potential applicability of KGM-based aerogels and provides an eco-friendly and convenient approach to efficiently remove trace As(III) from aqueous solutions.

Ultrasonic treatment of α-chitin regenerated from a NaOH/urea solvent with tunable capacity for stabilization of oil in water emulsion

α-chitin cannot be dispersed directly with ultrasonic treatment because of the strong intermolecular forces. However, in the current work, when α-chitin was first regenerated from a NaOH/urea solvent, the regenerated α-chitin can then be easily dispersed with ultrasonic treatment under weak acidic conditions. The morphology, size, zeta potential, structure and optical transmittance of the dispersed α-chitin solution were characterized by TEM, DLS, XRD and UV spectroscopy respectively. The dispersed chitin was then used for stabilization of oil in water emulsion. It was found that the emulsifying capacity of regenerated chitin was tunable by ultrasonic treatment. The dispersed chitin exhibited excellent emulsifying ability and the resulting emulsion was stable after long-term storage. In short, in this paper, a novel way to prepare dispersed chitin with excellent emulsifying ability was presented, and its emulsifying properties were further evaluated.

Effect of physical interactions on structure of lysozyme in presence of three kinds of polysaccharides

In this work the influences of κ-carrageenan (CRG), konjac glucomannan (KGM) and inulin on lysozyme (Ly)’s structure, activity, and their complex phase behavior were investigated through spectroscopy and activity measurement in heated and unheated conditions. It was found that the impact on the structure and activity of Ly was determined by the interactions with polysaccharides. After heat treatment, KGM and CRG improved the stability of complex systems. However, inulin did not have significant impact. Heating process promoted to change the structure of Ly, and the intervention retard following the sequence of CRG > KGM > inulin. The worthwhile work indicated protein’s structure and activity could be regulated by the interaction with polysaccharide, which might provide theoretical basis for food preservation and processing in different temperature treatments. Besides, the bidirectional effects of polysaccharide on protein would be beneficial to rational selection of functional properties of polysaccharide/protein systems.

Assessment of Vitamin D status in general population of Muzaffarabad district & effect of supplementation on serum Vitamin D levels in general population of Muzaffarabad district.

The status of vitamin D was assessed in the general population of the Muzaffarabad district having established coronary artery disease and other medical complaints. Results of the study showed that there is a deficiency or insufficiency of the vitamin in all the subjects enrolled for the study irrespective of their age, gender, occupation, socioeconomic conditions, daily sun exposure, supplementation history, body mass index and medical complaints. In the light of the findings that vitamin D is deficient or insufficient in 99% of the population and level is improved after administrating vitamin D as injection Sunny D. So it is suggested that the vitamin D supplementation may be added to the preventive program as a part of primary health care.