pH indicator films fabricated from soy protein isolate modified with chitin nanowhisker and Clitoria ternatea flower extract.

Sensor films are finding wide range of applications. Different type of sensing films is fabricated for the identification of chemicals, ions, heavy metals, changes in the pH, etc. The present report is on the fabrication of pH sensitive films from completely natural sources-soy protein isolate, chitin nano whiskers and flower extract. The highly crystalline chitin nano whiskers (CNW) were extracted from prawn shell under neutral condition via steam explosion technique. Multifunctional Soy protein isolate (SPI) films were prepared by adding chitin nanowhisker and Clitoria ternatea flower extract and its effect on thermal, mechanical and moisture properties of SPI film was investigated. The isolated CNW presented a needle like morphology with a diameter of 10-50 nm and a crystallinity index of 99.67%. The extracted chitin nanowhisker was used to prepare biodegradable films with soy protein isolate immobilized with anthocyanin from Clitoria ternatea flower extract. The prepared Soy protein -chitin nanowhisker films was found to have a tensile strength of about 15.45 ± 0.97 MPa with 8% chitin nanowhisker addition. The addition of CTE was found to decrease the tensile strength of SPI-CNW film but was found to make the film pH sensitive. The developed indicator film showed visible color changes in acidic and basic medium and hence can be used to monitor the freshness of food materials.

Development of starch based intelligent films by incorporating anthocyanins of butterfly pea flower and TiO2 and their applicability as freshness sensors for prawns during storage.

Intelligent pH sensitive starch films were developed by incorporation of anthocyanin pigment extracted from butterfly pea flower (BPE) and nanosized TiO2 using the method of solution casting. This research work evaluated the influence of BPE and TiO2 on the physical and structural properties of starch films. The physical properties of the starch films could be significantly altered by the addition of BPE and or TiO2. The starch films S/BPE and S/BPE/TiO2 exhibited higher barrier properties against water vapour as compared to the control films. Incorporation of BPE and TiO2 could decrease the thickness and moisture content of films. S, S/BPE starch films were transparent and, S/TiO2 and S/BPE/TiO2 films were opaque. Control starch films were colourless, whereas S/BPE films have purple colour. Owing to the inclusion of BPE and TiO2 particles, structural characterization by X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) did not show any major changes in polymer structure. Thermogravimetric analysis revealed that the addition of TiO2 enhanced the thermal stability of starch films to a significant extent. The color of different starch-based films was determined using the CIE Lab scale under different pH conditions and compared with the control. The fabricated (S/BPE and S/BPE/TiO2) films exhibited visually perceptible colour changes in the pH range between 1 and 12. Consequently these films could be used as intelligent pH indicators for monitoring the freshness of prawn seafood samples. During the storage of prawn food samples for 6 days, the color of the film changed from light pink to green which is a clear indication of spoilage of food material.

Novel core-shell dextran hybrid nanosystem for anti-viral drug delivery.

Zidovudine (AZT) is an antiviral drug extensively used for combating the global pandemic- HIV/AIDS. However, its uses are overshadowed by its short half -life, poor aqueous solubility and inability to cross physiological barriers. This study highlights a nanosystem consisting of dextran and stearic acid for AZT delivery. This hybrid nanoparticle was prepared by double emulsion solvent evaporation method. The morphological analysis of the prepared nanoparticles was carried out by transmission electron microscopy (TEM) and structural analysis through FTIR spectroscopy. Haemolysis, blood cell aggregation and cytotoxicity evaluations were also performed. These biological evaluations indicated that the nanoparticles were compatible and fluorescence microscopy studies demonstrated increased cellular internalization of drug loaded hybrid nanoparticles when compared with free drug molecules. The experimental outcomes indicate that the prepared nanoparticles are highly biocompatible haemocompatible and effective in getting internalized into cells of neural origin. These results highlight the feasibility and efficacy of the hybrid nanoparticles for effective delivery of zidovudine.

Electrospun polylactic acid-chitosan composite: a bio-based alternative for inorganic composites for advanced application.

Fabricating novel materials for biomedical applications mostly require the use of biodegradable materials. In this work biodegradable materials like polylactic acid (PLA) and chitosan (CHS) were used for designing electrospun mats. This work reports the physical and chemical characterization of the PLA-CHS composite, prepared by the electrospinning technique using a mixed solvent system. The addition of chitosan into PLA, offered decrease in fiber diameter in the composites with uniformity in the distribution of fibers with an optimum at 0.4wt% CHS. The fiber formation and the reduction in fiber diameter were confirmed by the SEM micrograph. The inverse gas chromatography and contact angle measurements supported the increase of hydrophobicity of the composite membrane with increase of filler concentration. The weak interaction between PLA and chitosan was confirmed by Fourier transform infrared spectroscopy and thermal analysis. The stability of the composite was established by zeta potential measurements. Cytotoxicity studies of the membranes were also carried out and found that up to 0.6% CHS the composite material was noncytotoxic. The current findings are very important for the design and development of new materials based on polylactic acid-chitosan composites for environmental and biomedical applications.

Gelatin modified lipid nanoparticles for anti- viral drug delivery.

The major challenges to clinical application of zidovudine are its moderate aqueous solubility and relative short half-life and serious side effects due to frequent administrations. We investigated the preparation of zidovudine-loaded nanoparticles based on lipids which were further modified with the polymer gelatin. Formulation and stability of the modified nanoparticles were analysed from the physico-chemical characterizations. The interactions of nanoparticles with blood components were tested by haemolysis and aggregation studies. The drug content and entrapment efficiencies were assessed by UV analysis. The effect of nanoparticles on protein adsorption was assessed by native polyacrylamide gel electrophoresis (PAGE). In vitro release studies showed a sustained release profile of zidovudine. In vitro cytotoxicity and cellular uptake of the zidovudine-loaded nanoparticles were performed in MCF-7 and neuro 2a brain cells. The enhanced cellular internalization of drug loaded modified nanoparticles in both the cell lines were revealed by fluorescence microscopy. Hence the present study focuses on the feasibility of zidovudine-loaded polymer modified lipid nanoparticles as carriers for safe and efficient HIV/AIDS therapy.

Novel dendritic structure of alginate hybrid nanoparticles for effective anti-viral drug delivery.

Lipid-polymer hybrid nanoparticles have recently gathered much attention as nanoplatforms for drug delivery applications due to their unique structural properties. In this study zidovudine (AZT) loaded hybrid nanoparticles of alginate (ALG) and stearic acid- poly ethylene glycol (SA-PEG) were synthesized. The structural characterization of drug loaded hybrid nanoparticles were studied using FT-IR spectroscopy, DLS and TEM analysis. These hybrid nanoparticles showed dendritic morphology and it can be used as an efficient carrier for zidovudine. In this drug loaded hybrid system of Alginate -Stearicacid/Poly (ethyleneglycol) Nanoparticles (ASNPs), AZT and alginate form the core wherein SA-PEG forms the external shell. We observed a dendritic morphology with internal voids and channels formed by the core molecule and the external shell forms the closed pack surface groups. The optimized formulation achieved a sub micron size of 407.67±19.18nm with drug encapsulation of 83.18±1.22%, and surface potential of -42.53mV, and has significant stability for six months. Haemolysis and aggregation studies revealed that there were no lysis and aggregation in WBC, RBC and platelets. In-vitro cytotoxicity and cellular uptake of the nanoparticles in Glioma, Neuro2a and Hela cells showed that ASNPs are non toxic. The results indicate that the synthesized hybrid nanoparticles represent a potential carrier for zidovudine, thus possibly increasing zidovudine's efficiency as an anti-HIV drug.

Evaluation of in-vitro cytotoxicity and cellular uptake efficiency of zidovudine-loaded solid lipid nanoparticles modified with Aloe Vera in glioma cells.

Zidovudine loaded solid lipid nanoparticles of stearic acid modified with Aloe Vera (AV) have been prepared via simple emulsion solvent evaporation method which showed excellent stability at room temperature and refrigerated condition. The nanoparticles were examined by Fourier transform infrared spectroscopy (FT-IR), which revealed the overlap of the AV absorption peak with the absorption peak of modified stearic acid nanoparticles. The inclusion of AV to stearic acid decreased the crystallinity and improved the hydrophilicity of lipid nanoparticles and thereby improved the drug loading efficacy of lipid nanoparticles. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) imaging revealed that, the average particle size of unmodified (bare) nanoparticles was 45.66±12.22nm and modified solid lipid nanoparticles showed an average size of 265.61±80.44nm. Solid lipid nanoparticles with well-defined morphology were tested in vitro for their possible application in drug delivery. Cell culture studies using C6 glioma cells on the nanoparticles showed enhanced growth and proliferation of cells without exhibiting any toxicity. In addition, normal cell morphology and improved uptake were observed by fluorescence microscopy images of rhodamine labeled modified solid lipid nanoparticles compared with unmodified nanoparticles. The cellular uptake study suggested that these nanoparticles could be a promising drug delivery system to enhance the uptake of antiviral drug by brain cells and it could be a suitable drug carrier system for the treatment of HIV.

Nanocelluloses from jute fibers and their nanocomposites with natural rubber: Preparation and characterization.

Nanocellulose fibers having an average diameter of 50nm were isolated from raw jute fibers by steam explosion process. The isolation of nanocellulose from jute fibers by this extraction process is proved by SEM, XRD, FTIR, birefringence and TEM characterizations. This nanocellulose was used as the reinforcing agent in natural rubber (NR) latex along with crosslinking agents to prepare crosslinked nanocomposite films. The effects of nanocellulose loading on the morphology and mechanics of the nanocomposites have been carefully analyzed. Significant improvements in the Young's modulus and tensile strength of the nanocomposite were observed because of the reinforcing ability of the nanocellulose in the rubber matrix. A mechanism is suggested for the formation of the Zn-cellulose complex. The three-dimensional network of cellulose nanofibers (cellulose/cellulose network and Zn/cellulose network) in the NR matrix plays a major role in improving the properties of the crosslinked nanocomposites.