Gaurav S. Dave

Biodegradable gelatin–ciprofloxacin–montmorillonite composite hydrogels for controlled drug release and wound dressing application

This work reports intercalation of a sparingly soluble antibiotic (ciprofloxacin) into layered nanostructure silicate, montmorillonite (MMT) and its reaction with bone derived polypeptide, gelatin that yields three-dimensional composite hydrogel. Drug intercalation results in changes in MMT layered space and drug loaded MMT and gelatin creates 3D morphology with biodegradable composite hydrogels. These changes can be correlated with electrostatic interactions between the drug, MMT and the gelatin polypeptides as confirmed by X-ray diffraction patterns, thermal, spectroscopic analyses, computational modeling and 3D morphology revealed by SEM and TEM analysis. No significant changes in structural and functional properties of drug was found after intercalation in MMT layers and composite hydrogels. In vitro drug release profiles showed controlled release up to 150h. The drug loaded composite hydrogels were tested on lung cancer cells (A549) by MTT assay. The results of in vitro cell migration and proliferation assay were promising as composite hydrogels induced wound healing progression. In vitro biodegradation was studied using proteolytic enzymes (lysozyme and protease K) at physiological conditions. This new approach of drug intercalation into the layered nanostructure silicate by ion-exchange may have significant applications in cost-effective wound dressing biomaterial with antimicrobial property.

A novel alkaline keratinase from Bacillus subtilis DP1 with potential utility in cosmetic formulation

The Bacillus subtilis DP1 was isolated from poultry farm soil at Anand district, India. The highest enzyme production (379.65U/ml) was obtained at pH 10.0, a temperature of 37°C and a growth period of 72h. The extracellular keratinase was purified by gel filtration chromatography with 27.98 purification fold. Purity was also confirmed by High-Performance Liquid Chromatography (HPLC) analysis, where a major peak having retention time of 2.5min was obtained on C18 column using photo diode array detector. Purified keratinase was stable in a broad range of pH (8-12) and temperature (20-50°C) with optimum at pH 10.0 and 37°C. The metallic ions, Ca(2+) and Mg(2+) enhance keratinase activity. Secondary structure from Circular Dichroism (CD) spectra implies that purified keratinase is largely β-pleated sheet rich protein. For preparation of dehairing cream formulation, compatibility studies of excipients were carried out. Fourier transform infrared spectroscopy (FTIR) spectra of sodium stearate, calcium carbonate and sodium lauryl sulphate shows no reactivity of functional groups and hence mixture was compatible for formulation of keratinase dehairing cream. Prepared biological depilatory was able to remove hair more efficiently compared to marketed formulations.

Isolation and partial purification of erythromycin from alkaliphilic Streptomyces werraensis isolated from Rajkot, India

An alkaliphilic actinomycete, BCI-1, was isolated from soil samples collected from Saurashtra University campus, Gujarat. Isolated strain was identified as Streptomyces werraensis based on morphological, biochemical and phylogenetic analysis. Maximum antibiotic production was obtained in media containing sucrose 2%, Yeast extract 1.5%, and NaCl 2.5% at pH 9.0 for 7 days at 30 °C. Maximum inhibitory compound was produced at pH 9 and at 30 °C. FTIR revealed imine, amine, alkane (C 000000000000 000000000000 000000000000 111111111111 000000000000 111111111111 000000000000 000000000000 000000000000 C) of aromatic ring and p-di substituted benzene, whereas HPLC analysis of partially purified compound and library search confirmed 95% peaks matches with erythromycin. Chloroform extracted isolated compound showed MIC values 1 μg/ml against Bacillus subtilis, ≤0.5 μg/ml against Staphylococcus aureus, ≤0.5 μg/ml against Escherichia coli and 2.0 μg/ml against Serretia GSD2 sp., which is more effective in comparison to ehtylacetate and methanol extracted compounds. The study holds significance as only few alkaliphilic actinomycetes have been explored for their antimicrobial potential.

A statistical approach for the enhanced production of thermostable alkaline protease showing detergent compatibility activity from Bacillus circulans

Abstract Response surface methodology (RSM) was employed to enhance the production of a thermostable alkaline protease from Bacillus circulans. Significant influences of peptone, yeast extract, and glucose on protease production were noted with a one-variable-at-a-time optimization strategy. Then, a full factorial central composite design (CCD) was applied to study the effects of glucose, peptone, and yeast extract to determine the optimal concentrations of these compounds for protease production by B. circulans under shake flask fermentation conditions. The statistical reliability and significance of the model was validated by an F-test for analysis of variance (ANOVA); enzyme production was improved significantly under optimized conditions. The enzyme was purified by ammonium sulphate fractionation, and gel filtration chromatography. Maximum enzyme activity was observed at 60°C temperature, and at pH 10. Alkaline protease from B. circulans showed excellent compatibility and stability in the presence of commercial detergents like Ariel, Surf Excel, Tide, Rin, Nirma, Wheel, and Doctor and showed excellent blood destaining effectiveness with commercial detergents.

Seaweed Pretreatment of Chickpea (Cicer arietinum) Enhances Post Harvest Preservation by Reducing Germination

The plant growth enhancer property of seaweeds has been studied in different crops. Seaweed (Sargassum wightii and Uluva lectuca) were collected from costal region of Mangrol and studied for its effect on germination and storage of chickpea. Chickpea seeds were soaked in 1% seaweed extracts for 6 h and dried at room temperature before sowing for germination in the soil. Percentage of seeds germination was less in S. wightii (67%) and U. lectuca (65%) treated seeds as compared to control. Furthermore, the treatment also prolonged germination time as compared to untreated control. Seaweed extracts effects on seeds viability upon longer storage was affected by the storage conditions. For instance, storage of seeds treated with seaweeds extracts at room temperature was more affected as compared to 4-8°C and -20°C. These results showed that seaweed extract is possible to use for increasing post harvest shelf life of chickpea without affecting its natural texture.