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Investigating the application of innovative antimicrobial surface coatings on medical devices is an important field of research. Many of these coatings have significant drawbacks, including biocompatibility, coating stability and the inability to effectively combat multiple drug-resistant bacteria. In this research, we developed an antibiofilm surface coating for medical catheters using biosynthesized silver nanoparticles (b-Cs-AgNPs) developed using leaves extract of Calliandra surinamensis. Various characterization techniques were employed to thoroughly characterize the synthesized b-Cs-AgNPs and c-AgNPs. b-Cs-AgNPs were compatible with human normal kidney cells and chicken embryos. It did not trigger any skin inflammatory response in in vivo rat model. b-Cs-AgNPs demonstrated potent zone of inhibition of 19.09 mm when subjected to the disc diffusion method in E. coli confirming strong antibacterial property. Different anti-bacterial assays including liquid growth curve, colony counting assay, biofilm formation assay supported the potent antimicrobial efficacy of b-Cs-AgNPs alone and when coated to medical grade catheters. Mechanistic studies reveal the presence of ferulic acid, that was important for the synthesis of b-AgNPs along with enhanced antibacterial effects of b-Cs-AgNPs compared to c-AgNPs, supported by molecular docking analysis. These results together demonstrated the effective role b-Cs-AgNPs in combating infections and mitigating biofilm formations, highlighting their need for further study in the field of biomedical applications.

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The present study considers the mathematical modelling of unsteady non-Newtonian hydro-magnetic nano-hemodynamics through a rigid cylindrical artery featuring two different stenoses (composite and irregular). The Ostwald-De Waele power-law fluid model is adopted to simulate the non-Newtonian characteristics of blood. Inspired by drug delivery applications for cardiovascular treatments, blood is considered doped with a homogenous suspension of biocompatible nanoparticles. The arterial vessel exhibits the permeability effect (lateral influx/efflux), and an external magnetic field is also applied in the radial direction to the flow. A combination of the Buongiorno and Tiwari-Das nanoscale models is adopted. The strongly nonlinear nature of the governing equations requires a robust numerical method, and therefore the finite difference technique is deployed to solve the resulting equations. Validation of solutions for the pure blood case (absence of nanoparticles) is included. Comprehensive solutions are presented for shear-thickening (n = 1.5) and shear-thinning (n = 0.5) blood flow for the effects of crucial nanoscale thermophysical, solutal parameters, and hydrodynamic parameters. Comparison of profiles (velocity, temperature, wall shear stress, and flow rate) is also made for composite and irregular stenosis. Colour visualization of streamline plots is included for pure blood and nano mediated blood both with and without applied magnetic field. The inclusion of nanoparticles (Cu/blood) within blood increases the axial velocity of blood. By applying external magnetic field in the radial direction, axial velocity is significantly damped whereas much less dramatic alterations are computed in blood temperature and concentration profiles. The simulations are relevant to the diffusion of nano-drugs in magnetic targeted treatment of stenosed arterial diseases.

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The present study considers the mathematical modeling of unsteady non-Newtonian hydro-magnetic nano-hemodynamics through a rigid cylindrical artery featuring two different stenoses (composite and irregular). The Ostwald-De Waele power-law fluid model is adopted to simulate the non-Newtonian characteristics of blood. Inspired by drug delivery applications for cardiovascular treatments, blood is considered doped with a homogenous suspension of biocompatible nanoparticles. The arterial vessel exhibits the permeability effect (lateral influx/efflux), and an external magnetic field is also applied in the radial direction to the flow. A combination of the Buongiorno and Tiwari-Das nanoscale models is adopted. The strongly nonlinear nature of the governing equations requires a robust numerical method, and therefore the finite difference technique is deployed to solve the resulting equations. Validation of solutions for the pure blood case (absence of nanoparticles) is included. Comprehensive solutions are presented for shear-thickening (n = 1.5) and shear-thinning (n = 0.5) blood flow for the effects of crucial nanoscale thermophysical, solutal parameters, and hydrodynamic parameters. Comparison of profiles (velocity, temperature, wall shear stress, and flow rate) is also made for composite and irregular stenosis. Colour visualization of streamline plots is included for pure blood and nano mediated blood both with and without applied magnetic field. The inclusion of nanoparticles (Cu/blood) within blood increases the axial velocity of blood. By applying external magnetic field in the radial direction, axial velocity is significantly damped whereas much less dramatic alterations are computed in blood temperature and concentration profiles. The simulations are relevant to the diffusion of nano-drugs in magnetic targeted treatment of stenosed arterial diseases.

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OBJECTIVE: The objective of the present work was to formulate and to characterize controlled release matrix tablets of losartan potassium in order to improve bioavailability and to minimize the frequency of administration and increase the patient compliance. MATERIALS AND METHODS: Losartan potassium controlled release matrix tablets were prepared by direct compression technique by the use of different natural, synthetic and semisynthetic polymers such as gum copal, gum acacia, hydroxypropyl methyl cellulose K100 (HPMC K100), eudragit RL 100 and carboxy methyl ethyl cellulose (CMEC) individually and also in combination. Studies were carried out to study the influence of type of polymer on drug release rate. All the formulations were subjected to physiochemical characterization such as weight variation, hardness, thickness, friability, drug content, and swelling index. In vitro dissolution studies were carried out simulated gastric fluid (pH 1.2) for first 2 h and followed by simulated intestinal fluid (pH 6.8) up to 24 h, and obtained dissolution data were fitted to in vitro release kinetic equations in order to know the order of kinetics and mechanism of drug release. RESULTS AND DISCUSSION: Results of physiochemical characterization of losartan potassium matrix tablets were within acceptable limits. Formulation containing HPMC K100 and CMEC achieved the desired drug release profile up to 24 h followed zero order kinetics, release pattern dominated by Korsmeyer - Peppas model and mechanism of drug release by nonfickian diffusion. The good correlation obtained from Hixson-Crowell model indicates that changes in surface area of the tablet also influences the drug release. CONCLUSION: Based on the results, losartan potassium controlled release matrix tablets prepared by employing HPMC K100 and CMEC can attain the desired drug release up to 24 h, which results in maintaining steady state concentration and improving bioavailability.