Heat and mass transfer on MHD rotating Casson Blood-CNTs nanofluid flow in porous channel for biomedical applications

Rotating flow in a channel is a key mechanism in various biomedical applications, including rotating atherectomy, artificial hearts, and hemodialysis systems. While most studies focus on experimental and surgical applications, theoretical investigations on rotating blood flow incorporating carbon nanotubes (CNTs) remain largely unexplored. The channel configuration is considered as effectively represents the cross-section of blood vessels. CNTs nanofluids exhibit superior heat transfer properties compared to conventional fluids and other nanoparticle-based nanofluids, making them highly advantageous for medical applications such as targeted drug delivery and thermal therapies. This study examines the effects of suspending single-wall and multi-wall carbon nanotubes (SWCNTs and MWCNTs) in human blood, modeled as a Casson nanofluid, on the unsteady magnetohydrodynamic (MHD) flow in a rotating channel across a porous medium. The problem is formulated using a set of dimensional partial differential equations (PDEs) under suitable initial and boundary conditions, which are then nondimensionalized using relevant dimensionless variables. The resultant equations are further tackled analytically using the Laplace transform method, yielding closed form of velocity, temperature, and concentration solutions. The results indicate that increasing rotation reduces primary velocity while enhancing secondary velocity, which are essential in preventing vascular diseases. A higher CNTs volume fraction boosts both velocity components, facilitating faster drug transport. The presence of CNTs also improves heat transfer efficiency, with SWCNTs demonstrating a 42.66 % Nusselt number increase at the moving plate and 390.28 % at the stationary plate, outperforming MWCNTs. These findings highlight the potential of CNT-blood nanofluids in medical applications requiring efficient thermal regulation, offering insights into optimizing heat and mass transfer in biomedical devices.

Impact of gold and silver nanoparticles injected in blood with viscous dissipation

A nano-blood model is developed to study the flow of gold- and silver-infused blood through a porous, stenotic artery under Newtonian assumptions. Wall curvature, convective heating, wall motion, and viscous dissipation are considered. Darcy's model simulates porous resistance, and the Tiwari-Das model captures nanoparticle effects. Governing equations are reduced via similarity transformations and solved using MATLAB's bvp4c solver. Validation against existing studies is provided. Results show gold-blood nanofluid achieves higher velocities than silver-blood. Increasing the Biot number enhances cooling at the arterial wall. Detailed graphs and 3D contour plots illustrate the effects on temperature, velocity, skin friction, and Nusselt number.

Shape Matters: Impact of Mesoporous Silica Nanoparticle Morphology on Anti-Tumor Efficacy

A nanoparticle's shape is a critical determinant of its biological interactions and therapeutic effectiveness. This study investigates the influence of shape on the performance of mesoporous silica nanoparticles (MSNs) in anticancer therapy. MSNs with spherical, rod-like, and hexagonal-plate-like shapes were synthesized, with particle sizes of around 240 nm, and their other surface properties were characterized. The drug loading capacities of the three shapes were controlled to be 47.46%, 49.41%, and 46.65%, respectively. The effects of shape on the release behaviors, cellular uptake mechanisms, and pharmacological behaviors of MSNs were systematically investigated. Through a series of in vitro studies using 4T1 cells and in vivo evaluations in 4T1 tumor-bearing mice, the release kinetics, cellular behaviors, pharmacological effects, circulation profiles, and therapeutic efficacy of MSNs were comprehensively assessed. Notably, hexagonal-plate-shaped MSNs loaded with PTX exhibited a prolonged circulation time (t1/2 = 13.59 ± 0.96 h), which was approximately 1.3 times that of spherical MSNs (t1/2 = 10.16 ± 0.38 h) and 1.5 times that of rod-shaped MSNs (t1/2 = 8.76 ± 1.37 h). This research underscores the significance of nanoparticles' shapes in dictating their biological interactions and therapeutic outcomes, providing valuable insights for the rational design of targeted drug delivery systems in cancer therapy.

Unsteady natural convection flow of blood Casson nanofluid (Au) in a cylinder: nano-cryosurgery applications

Nano-cryosurgery is one of the effective ways to treat cancerous cells with minimum harm to healthy adjacent cells. Clinical experimental research consumes time and cost. Thus, developing a mathematical simulation model is useful for time and cost-saving, especially in designing the experiment. Investigating the Casson nanofluid's unsteady flow in an artery with the convective effect is the goal of the current investigation. The nanofluid is considered to flow in the blood arteries. Therefore, the slip velocity effect is concerned. Blood is a base fluid with gold (Au) nanoparticles dispersed in the base fluid. The resultant governing equations are solved by utilising the Laplace transform regarding the time and the finite Hankel transform regarding the radial coordinate. The resulting analytical answers for velocity and temperature are then displayed and visually described. It is found that the temperature enhancement occurred by arising nanoparticles volume fraction and time parameter. The blood velocity increases as the slip velocity, time parameter, thermal Grashof number, and nanoparticles volume fraction increase. Whereas the velocity decreases with the Casson parameter. Thus, by adding Au nanoparticles, the tissue thermal conductivity enhanced which has the consequence of freezing the tissue in nano-cryosurgery treatment significantly.

Computational simulation of rheological blood flow containing hybrid nanoparticles in an inclined catheterized artery with stenotic, aneurysmal and slip effects

Influenced by nano-drug delivery applications, the present article considers the collective effects of hybrid biocompatible metallic nanoparticles (Silver and Copper), a stenosis and an aneurysm on the unsteady blood flow characteristics in a catheterized tapered inclined artery. The non-Newtonian Carreau fluid model is deployed to represent the hemorheological characteristics in the arterial region. A modified Tiwari-Das volume fraction model is adopted for nanoscale effects. The permeability of the arterial wall and the inclination of the diseased artery are taken into account. The nanoparticles are also considered to have various shapes (bricks, cylinders, platelets, blades) and therefore the influence of different shape parameters is discussed. The conservation equations for mass, linear momentum and energy are normalized by employing suitable non-dimensional variables. The transformed equations with associated boundary conditions are solved numerically using the FTCS method. Key hemodynamic characteristics i.e. velocity, temperature, flow rate, wall shear stress (WSS) in stenotic and aneurysm region for a particular critical height of the stenosis, are computed. Hybrid nanoparticles (Ag-Cu/Blood) accelerate the axial flow and increase temperatures significantly compared with unitary nanoparticles (Ag/blood), at both the stenosis and aneurysm segments. Axial velocity, temperature and flow rate are all enhanced with greater nanoparticle shape factor. Axial velocity, temperature, wall shear stress and flow rate magnitudes are always comparatively higher at the aneurysm region compared with the stenotic segment. The simulations provide novel insights into the performance of different nanoparticle geometries and also rheological behaviour in realistic nano-pharmaco-dynamic transport and percutaneous coronary intervention (PCI).