Molecular Recognition between Anticancer Drug, Regorafenib and Human Serum Albumin: Interaction Revisited

The wet-lab techniques (fluorimetry and spectrophotometry), along with computational techniques (molecular docking and molecular dynamics (MD) simulation), were applied to re-examine the association of an anticancer drug, regorafenib (REG) with human serum albumin (HSA). The REG-induced protein fluorescence quenching was characterized as static quenching based on a decrement in the KSV (Stern-Volmer constant) with increasing temperature and hyperchromic effect in the absorption spectra. The REG–HSA complex (Ka = 0.63 – 1.17 × 105 M–1) was stabilized by hydrophobic and van der Waals interactions in combination with hydrogen bonds, as revealed by thermodynamic data (ΔrS° = +17.17 J mol–1 K–1 and ΔrH° = –23.00 kJ mol–1), and further supported by molecular docking assessment. Microenvironmental fluctuations around HSA fluorophores and better protein stability against thermal stress were evident due to REG-HSA complexation. Accessibility of both Sudlow\u27s Sites I and II but priority for Site I of the protein for REG was inferred by the competitive ligand displacement and molecular docking assessments. MD simulation results supported the stability of the complex

In-situ Development of Highly Photocatalytic Multifunctional Nanocomposites by Ultrasonic Acoustic Method

Cotton-titania nanocomposites with multifunctional properties were synthesized through ultrasonic acoustic method (UAM). Ultrasonic irradiations were used as a potential tool to develop cotton-titania (CT) nanocomposites at low temperature in the presence of titanium tetrachloride and isopropanol. The synthesized samples were characterized by XRD, SEM, EDX and ICP-OES methods. Functional properties i.e. Ultraviolet protection factor (UPF), self-cleaning, washing durability, antimicrobial and tensile strength of the CT nanocomposites were evaluated by different methods. Central composite design and response surface methodology were employed to evaluate the effects of selected variables on responses. The results confirm the simultaneous formation and incorporation of anatase TiO2 with average crystallite size of 4 nm on cotton fabric with excellent photocatalytic properties. The sustained self-cleaning efficiency of CT nanocomposites even after 30 home launderings indicates their excellent washing durability. Significant effects were obtained during statistical analysis for selected variables on the formation and incorporation of TiO2 nanoparticles (NPs) on cotton and photocatalytic properties of the CT nanocomposites