Silk Mat as Bio-matrix for the Immobilization of Cholesterol Oxidase

Cholesterol oxidase (ChOx) was covalently immobilized onto the woven silk fiber (silk mat) produced by Antheraea assamensis. The immobilization was done using N-ethyl-N’-(3-dimethylaminopropyl) carbodimide and N-hydroxysuccinimide ligand chemistry. The attachment of ChOx to the silk mat was demonstrated by scanning electron microscopy and activity study. The kinetic studies of the immobilized ChOx were performed by using a biological oxygen monitor. The enzyme loading was found to be 0.046 U cm^?2 of silk mat and the enzyme loading efficiency of the silk mat was estimated to be 70%. Remarkably high storage and operational stability (t_1/2 of initial activities) corresponding to 13 months and 25 numbers of assay (for a period of 6 h), respectively, of the fabricated ChOx electrode were demonstrated.     

A New Isolate from Fusarium proliferatum (AUF-2) for Efficient Nitrilase Production

A fungal isolate from Fusarium proliferatum strain AUF-2 has been found to have a high nitrilase activity (≥1,000 U/l culture). The present work describes optimization of growth conditions and production medium to achieve maximum nitrilase production. The most effective carbon and nitrogen sources for nitrilase production were glucose and sodium nitrate, respectively. ε-Caprolactam was found to be the best inducer for maximum nitrilase production with 80 g/l wet cell biomass and 26 U/g nitrilase activity. An overall nitrilase activity of ≥2,000 U/l culture was obtained in this study, which is one of the best activities reported so far in any Fusarium strain. Chemo-profiling has shown that the strain is versatile in its ability to hydrolyze both aliphatic as well as aromatic nitriles. Efforts are being made to use the strain for biotransformation of pharmaceutical substrates.     

Design and development of bioactive α-hydroxy carboxylate group modified MnFe2O4 nanoparticle: Comparative fluorescence study,magnetism and DNA nuclease activity

Three new α-hydroxy carboxylate group functionalized MnFe₂O₄ nanoparticles (NPs) have been developed to explore the microscopic origin of ligand modified fluorescence and magnetic properties of nearly monodispersed MnFe₂O₄ NPs. The surface functionalization has been carried out with three small organic ligands (tartrate, malate, and citrate) having different number of α-hydroxy carboxylate functional group along with steric effect. Detailed study unveils that α-hydroxy carboxylate moiety of the ligands plays key role to generate intrinsic fluorescence in functionalized MnFe₂O₄ NPs through the activation of ligand to metal charge transfer transitions, associated with ligand–Mn²⁺/Fe³⁺ interactions along with d–d transition corresponding to d–orbital energy level splitting of Fe³⁺ ions on NP surface. Further, MnFe₂O₄ NPs show a maximum 140.88% increase in coercivity and 97.95% decrease in magnetization compared to its bare one upon functionalization. The ligands that induce smallest crystal field splitting of d–orbital energy level of transition metal ions are found to result in strongest ferrimagnetic activation of the NPs. Finally, our developed tartrate functionalized MnFe₂O₄ (T-MnFe₂O₄) NPs have been utilized for studying DNA binding interaction and nuclease activity for stimulating their beneficial activities toward diverse biomedical applications. The spectroscopic measurements indicate that T-MnFe₂O₄ NPs bind calf thymus DNA by intercalative mode. The ability of T-MnFe₂O₄ NPs to induce DNA cleavage was studied by gel electrophoresis technique where the complex is found to promote the cleavage of pBR322 plasmid DNA from the super coiled form I to linear coiled form II and nicked coiled form III with good efficiency.     

Role of Resveratrol in Prevention and Control of Cardiovascular Disorders and Cardiovascular Complications Related to COVID-19 Disease: Mode of Action and Approaches Explored to Increase Its Bioavailability

Resveratrol is a phytoalexin produced by many plants as a defense mechanism against stress-inducing conditions. The richest dietary sources of resveratrol are berries and grapes, their juices and wines. Good bioavailability of resveratrol is not reflected in its high biological activity in vivo because of resveratrol isomerization and its poor solubility in aqueous solutions. Proteins, cyclodextrins and nanomaterials have been explored as innovative delivery vehicles for resveratrol to overcome this limitation. Numerous in vitro and in vivo studies demonstrated beneficial effects of resveratrol in cardiovascular diseases (CVD). Main beneficial effects of resveratrol intake are cardioprotective, anti-hypertensive, vasodilatory, anti-diabetic, and improvement of lipid status. As resveratrol can alleviate the numerous factors associated with CVD, it has potential as a functional supplement to reduce COVID-19 illness severity in patients displaying poor prognosis due to cardio-vascular complications. Resveratrol was shown to mitigate the major pathways involved in the pathogenesis of SARS-CoV-2 including regulation of the renin-angiotensin system and expression of angiotensin-converting enzyme 2, stimulation of immune system and downregulation of pro-inflammatory cytokine release. Therefore, several studies already have anticipated potential implementation of resveratrol in COVID-19 treatment. Regular intake of a resveratrol rich diet, or resveratrol-based complementary medicaments, may contribute to a healthier cardio-vascular system, prevention and control of CVD, including COVID-19 disease related complications of CVD.