Modulating the Effect of ß-Sitosterol Conjugated with Magnetic Nanocarriers to Inhibit EGFR and Met Receptor Cross Talk.

The cross-talk between the EGFR (Epidermal Growth Factor Receptor) and MET (Hepatocyte Growth Factor Receptor) poses a significant challenge in the field of molecular signaling. Their intricate interplay leads to dysregulation and contributes to cancer progression and therapeutic resistance. ß-Sitosterol (BS), a plant sterol with promising anticancer properties, shows increased research on its potential as a chemopreventive agent. However, significant modifications are required to deliver BS in cancer cells due to its lower efficacy. The present work aims to design a carrier-mediated delivery system specifically targeting cancer cells with EGFR and MET receptor cross-talk. Surface modification of BS was performed with superparamagnetic iron oxide nanoparticles (SPIONs), polyethylene glycol (PEG), and poly(N-isopropylacrylamide) (PNIPAM) to enhance the delivery of BS at the target site. BS was conjugated with SPIONs (BS-S), PNIPAM (BS-SP), PEG, and PNIPAM (BS-SPP) polymers, respectively, and the conjugated complexes were characterized. Results showed an increase in size, stability, and monodispersity in the following order, BS-S, BS-SP, and BS-SPP. The drug encapsulation efficiency was observed to be highest in BS-SPP (82.5%), compared to BS-S (61%) and BS-SP (74.9%). Sustained drug release was achieved in both BS-SP (82.6%) and BS-SPP (83%). The IC 50 value of BS, BS-S, BS-SP, and BS-SPP towards MCF 7 was 242 µg/mL,197 µg/mL, 168 µg/mL, and 149 µg/mL, HEPG2 was 274 µg/mL, 261 µg/mL, 233 µg/mL and 207 µg/mL and NCIH 460 was 191 µg/mL, 185 µg/mL, 175 and 164 µg/mL, indicating highest inhibition towards NCIH 460 cells. Our results conclude that ß-sitosterol conjugated with SPION, PEG, and PNIPAM could be a potential targeted therapy in inhibiting EGFR and MET receptor-expressing cancer cells.

Toxicological evaluation of biosynthesised hematite nanoparticles in vivo.

In recent years, nanomaterials have been widely used in consumer products. High reactivity of metallic nanoparticles and its bioaccumulation in biological systems are the main causes of concern over their safety to human health and environment. The available information related to the safety of several nanomaterials is insufficient. Hematite nanoparticles are proposed for various applications. Ecotoxicological studies of hematite nanoparticles are very limited. In the present study, biosynthesised hematite nanoparticles using Bacillus cereus were evaluated for its acute oral toxicity in mice following OECD guidelines. A dose of 2 g/kg/p.o was administered to Swiss albino mice through gastric oral feeding tube and observed for 14 days. After two weeks blood samples were collected and subjected for evaluation of haematological parameters and biochemical analysis. There was no mortality and toxic signs of animals till the end of observational period. The animals were sacrificed and organs like liver and kidneys were isolated to study the histopathological changes. The results of the study revealed that there was no drastic change in parameters except slight change in bilirubin in the hematite nanoparticle treated mice. Biosynthesised hematite nanoparticles were assayed for toxicity in Artemia salina. Cysts treated with higher concentrations of hematite nanoparticles showed small sized nauplii. Biosynthesised hematite nanoparticles were found to be non-toxic to A. salina nauplii in lower concentrations.

3D structure prediction of VAPC1 and identification of dual natural inhibitors for VPAC1 and EGFR.

Vasoactive intestinal polypeptide receptor 1 (VPAC1) and epidermal growth factor receptor (EGFR) are associated with signal transduction pathways relevant to neuroblastoma, cancer of breast, prostate and lungs. In order to identify appropriate ligand analogues for simultaneous inhibition of EGFR and VPAC1, in-silico homology modelling of VPAC1 and its characterization by molecular interaction studies have been undertaken. Homology modelling was performed with the Swiss Model and validation of the predicted 3D structure was carried out using PROCHECK and RAMPAGE. Ramachandran's plot of the predicted structure from this two software revealed that 92% and 94% of the residues were in the most favoured region, respectively. Compounds screened from Naturally Occurring Plant-based Anti-Cancerous Compound-Activity-Target (NPACT) database having strong interactions with EGFR were further checked for ADMET properties. Molecular interaction studies revealed four compounds namely Fisetin, Genistein, Tectorigenin, and Tephrosin docked with VPAC1 having respective binding energies of -7.1, -6.98, -6.9 and - 6.61 kcal/mol. Fisetin and Genistein with a rotatable bond and lower molecular weight increased their drug-likeness than the others. Therefore, simultaneous inhibition of VPAC1 and EGFR, in turn, might inhibit the progression of breast carcinoma. The results obtained were further substantiated by comparing them with positive and negative controls. Quercetin was used as positive control, and strong binding energy of -7.54 kcal/mol with EGFR is in accordance with experimental evidence. 3-O-cis-p coumaroyl alphitolic acid was used as negative control, where docking was not possible in absence of binding with either EGFR or VIPR1.

Potential of metabolic engineering in bacterial nanosilver synthesis.

The widespread applications of silver nanoparticles in present days demand an industrial-scale production process. The ability of bacteria to synthesise silver nanoparticles can be exploited to overcome many shortcomings associated with conventional production processes, such as high cost and nanoparticle toxicity. However, lack of a standardised protocol and suboptimal yield remain a major obstacle for bacterial synthesis route. A potential, yet unexplored, solution to this problem could be envisioned through rewiring of the metabolic network to direct cellular resources towards the product of interest. Mathematical modelling of metabolic pathway is the key to understand and manipulate the cellular metabolism for enhanced production of desired metabolite(s). The present study provides a perspective on the scope of metabolic engineering approaches to enhance bacterial synthesis of silver nanoparticles.

Evaluation of cytotoxicity of hematite nanoparticles in bacteria and human cell lines.

Metal nanoparticles have a great impact and even change the composition of soil microbial communities. This poses the risk of their accumulation in the ecosystem, which may call on health hazard. Statistical techniques such as Plackett-Burman design, Response Surface Methodology were used for optimizing medium constituents for Bacillus cereus SVK1 and other critical variables responsible for the production of biomolecules and biosynthesis of hematite nanoparticles. The effect of hematite nanoparticles on the growth of soil bacteria were tested by agar-well diffusion method and dynamic growth curve techniques. Bacterial growth inhibition was not observed with hematite nanoparticle concentration of up to 25mg/mL. In addition, hematite nanoparticles enhanced the growth of the soil bacteria. The results show that hematite nanoparticles were non-toxic to soil bacteria indicating their scope for wide range of applications. The effective cytotoxic concentration (CTC50) of hematite nanoparticles against MCF-7, A549, Hep3B and Vero cell lines was found to be 207.58, 224.69, 193.26 and 2530µg/mL respectively. Hematite nanoparticles didn't cause lysis of red blood cells.

Optimization of process parameters for the rapid biosynthesis of hematite nanoparticles.

Hematite (α-Fe2O3) nanoparticles are widely used in various applications including gas sensors, pigments owing to its low cost, environmental friendliness, non-toxicity and high resistance to corrosion. These nanoparticles were generally synthesized by different chemical methods. In the present study, nanoparticles were synthesized rapidly without heat treatment by biosynthesis approach using culture supernatant of Bacillus cereus SVK1. The physiochemical parameters for rapid synthesis were optimized by using UV-visible spectroscopy. The time taken for hematite nanoparticle synthesis was found to increase with the increasing concentration of the precursor. This might be due to the inadequate proportion of quantity of biomolecules present in the culture supernatant to the precursor which led to delayed bioreduction. Greater quantities of culture supernatant with respect to precursor lead to rapid synthesis of hematite nanoparticles. The nucleation of the hematite nucleus happens more easily when the solution pH was less than 10. The optimum parameters identified for the rapid biosynthesis of hematite nanoparticles were pH9, 37°C (temperature) and 1mM ferric chloride as precursor. The particles were well crystallized hexagonal structured hematite nanoparticles and are predominantly (110)-oriented. The synthesized nanoparticles were found to contain predominantly iron (73.47%) and oxygen (22.58%) as evidenced by Energy Dispersive X-ray analysis. Hematite nanoparticles of 15-40nm diameters were biosynthesized in 48h under optimized conditions, compared to 21days before optimization.

Biosynthesis of hematite nanoparticles and its cytotoxic effect on HepG2 cancer cells.

Iron oxide nanoparticles were gaining significant importance in a variety of applications due to its paramagnetic properties and biocompatibility. Various chemical methods were employed for hematite nanoparticle synthesis which require special equipment or a complex production process. In this study, protein capped crystalline hexagonal hematite (α-Fe2O3) nanoparticles were synthesized by green approach using culture supernatant of a newly isolated bacterium, Bacillus cereus SVK1 at ambient conditions. The synthesized nanoparticles were characterized by electron microscopy, X-ray diffraction, UV-visible spectroscopy and Fourier transform infrared spectroscopic analysis. Nanoparticles were evaluated for its possible anticancer activity against HepG2 liver cancer cells by MTT assay. Hematite nanoparticles with an average diameter of 30.2 nm, exhibited a significant cytotoxicity toward HepG2 cells in a concentration-dependent manner (CTC50=704 ng/ml).