Nanoparticle Suspensions Research Articles

Numerical simulation of unsteady blood based Carreau nanofluid flow in an inclined porous saturated artery having overlapping stenosis with electro-osmosis

The present paper focuses on the computational modeling of the unsteady non-Newtonian electro-magnetohydrodynamic flow of nano-blood through the inclined and tapered saturated porous artery with overlapping stenosis. The Carreau fluid model is adopted to simulate the non-Newtonian behavior of the blood. This study also uses a modified form of Darcy’s law applied to the Carreau model. Blood is doped with a suspension of homogeneous biocompatible nanoparticles of different shapes. In addition, a combination of a magnetic field and an electric field has also been taken into account. The significance of this work rests in the ability to enhance comprehension of the complicated behavior of hemodynamic flow when exposed to external fields and porous media with the addition of nanoparticles, which has substantial implications for the regulation and treatment of cardiovascular diseases. The finite-difference method is used to obtain the solution of the resulting equations. The simulations are applicable to targeted magnetic therapy for stenotic artery disease and the delivery of nanomedicines.

Potential-Modulated Surface-Enhanced Raman Spectroscopy of Tolmetin at Gold Nanoparticle Film Functionalized Polarizable Liquid-Liquid Interfaces.

An aqueous colloidal suspension of gold nanoparticles (AuNPs) may be condensed into a thin fractal film at the polarizable liquid-liquid interface formed between two immiscible electrolyte solutions upon injection of millimolar concentrations of sodium chloride to the aqueous phase. By adjusting the interfacial polarization conditions (negative, intermediate, and positive open-circuit potentials), the morphology of the film is modified, resulting in unique surface plasmon properties of the film, which enable in situ surface-enhanced Raman spectroscopy (SERS). Intense SERS signals are observed at the polarizable liquid-liquid interface when micromolar concentrations of tolmetin, a nonsteroidal anti-inflammatory drug, are entrapped in the AuNP fractal film. The change in the signal intensity, averaged over multiple spectra, with respect to the concentration of tolmetin, depends on the polarization conditions and suggests the presence of chemical-induced damping effects on the surface plasmons of the gold film.

Optical tweezers for probing the interactions of ZnO and Ag nanoparticles with E. coli.

The antibacterial effect of nanoparticles is mainly studied on the ensembles of the bacteria. In contrast, the optical tweezer technique allows the investigation of similar effects on individual bacterium. E. coli is a self-propelled micro-swimmer and ATP-driven active microorganism. In this work, an optical tweezer is employed to examine the mechanical properties of E. coli incubated with ZnO and Ag nanoparticles (NP) in the growth medium. ZnO and Ag NP with a concentration of 10µg/ml were dispersed in growth medium during active log-growth phase of E. coli. This E. coli-NP incubation is further continued for 12h. The E. coli after incubation for 2h, 6h and 12h were separately studied by the optical tweezer for their mechanical property. The IR laser (λ = 975 nm; power = 100mW) was used for trapping the individual cells and estimated trapping force, trapping stiffness and corner frequency. The optical trapping force on E. coli incubated in nanoparticle suspension shows linear decreases with incubation time. This work brings the importance of optical trapping force measurement in probing the antibacterial stress due to nanoparticles on the individual bacterium.

Abstract PO2-23-06: Clinical study of stained region lymph node biopsy (SrLNB) in axillary surgery after neoadjuvant systemic therapy in patients with axillary lymph node positive breast cancer

Abstract Background The probability of axillary lymph node converting from positive to negative after neoadjuvant systemic therapy (NST) for breast cancer patients is approximately 40%. A variety of axillary lymph node biopsy surgeries based on sentinel lymph node biopsy (SLNB) can help to omit axillary lymph node dissection (ALND). The common disadvantages, however, are mainly the restrictions, such as the need for strict regulation of the use of radiotracers, the high number of retrieved lymph nodes required, and the need to purchase ancillary equipment. The more restrictions there are, the more they limit the spread and availability of the technique and, more importantly, reduce the number of patients who will benefit. In fact, for patients with metastatic lymph nodes, the sentinel lymph nodes must be included in the lymph nodes that have metastasized. If these metastatic lymph nodes can be accurately marked and precisely retrieved after NST, it is possible to assess whether the axillary lymph nodes are converted from positive to negative without the need for SLNB. Materials and methods Breast cancer patients with pathologically confirmed axillary lymph node metastases who were receiving NST were recruited for this study. Before NST, carbon nanoparticles suspension injections were injected into the cortex of the pathologically confirmed metastatic lymph node to stain the region where the metastatic lymph node was located. The lymph nodes in the stained region were retrieved by stained region lymph node biopsy (SrLNB) during the axillary surgery, followed by ALND, without the use of SLNB. Finally, the identification rate and false-negative rate (FNR) of SrLNB were statistically analyzed according to pathology data. Results A total of 159 patients were successfully enrolled in this study between September 24, 2020 and December 2, 2022, with an axillary pCR rate of 40.9% (65/159). The identification rate of SrLNB was 100% (159/159), with an overall FNR of 5.3% (5/94). Subgroup analysis revealed that in the subgroups of 1, 2, 3 and ≥4 SrLN, the FNR was 0%, 0%, 0% and 8.9% (5/56), respectively, whereas in the cN1, cN2 and cN3 subgroups the FNR was 7.7% (3/39), 2.6% (1/38) and 5.9% (1/17), respectively. The FNR indexes were within the safety threshold of 10% in all subgroups. Conclusion SrLNB has a high identification rate and a low FNR and is useful for screening patients with positive to negative axillary lymph nodes for omitting ALND. srLNB requires only the use of an affordable and radiation-free carbon nanoparticles suspension injection for marking, making the whole technique simpler and easier to disseminate. The data from this study also suggest that SLNB may not be mandatory for axillary biopsy in patients with positive axillary lymph nodes undergoing NST. Table 1. General characteristics of enrolled patients. Table 2. Analysis of factors affecting axillary pCR rates. Table 3. Analysis for the FNR of SrLNB. Citation Format: Jue Wang, Rui Chen, Cuiying Li, Hailing Zha, Qiannan Zhu, Lifeng Huang, Xiaoming Zha. Clinical study of stained region lymph node biopsy (SrLNB) in axillary surgery after neoadjuvant systemic therapy in patients with axillary lymph node positive breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-23-06.

Engagement of modified heat and mass fluxes on thermally radiated boundary layer flow past over a stretched sheet via OHAM analysis

This work investigates advanced heat transfer mechanisms in boundary-layer flow of nanofluids over a stretchable sheet. The comprehensive model integrates radiation effects, Brownian motion, thermophoresis, Cattaneo-Christov heat flux and Magnetohydrodynamics (MHD). Nanofluids, composed of a base fluid with suspended nanoparticles, exhibit distinct thermophysical properties crucial for influencing heat and mass transfer dynamics. Through rigorous numerical analysis, key parameters such as nanoparticle volume fraction, stretching sheet velocity, Cattaneo-Christov parameter, radiation parameter, and magnetic field strength are examined. The findings reveal intricate interactions among these parameters, providing a thorough understanding of their combined impact on temperature and velocity characteristics inside the boundary layer. This research contributes significantly to fundamental knowledge in nanofluid dynamics and provides practical insights for optimizing heat transfer processes and fluid behavior over-stretching surfaces, especially in the context of advanced heat transfer mechanisms. The implications extend across diverse engineering disciplines and materials science, offering valuable guidance for designing and improving processes involving nanofluid flows over-stretching sheets. With respect to the magnetic field parameter, the fluid velocity exhibits a decreasing attitude.The temperature function enhances with higher R\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal{R}$$\\end{document} values but diminishes with increasing Pr\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\mathcal{P}\\mathcalligra{r}$$\\end{document} values.

Simple two-step synthesis of Ag/ZnO nanoparticles with enhanced photocatalytic response

This study presents a simple two-step synthesis method for the fabrication of Ag/ZnO nanocomposites to improve the photocatalytic response of ZnO. The synthesis involves ZnO nanoparticles that were fabricated from the thermal decomposition of commercial zinc acetate. In order to produce Ag/ZnO nanoparticles in a simple two-step process, ZnO nanoparticles were mixed with Ag nanoparticle suspensions previously obtained by the laser ablation of solids in liquids technique at three different fluences. Structural characterization of ZnO powders revealed the presence of single phase wurtzite ZnO nanoparticles with crystal sizes of 20 nm. On the other hand, XRD patterns for a composite sample revealed the presence of signals associated to both ZnO and Ag suggesting that silver nanoparticles were attached to the ZnO particles surface. Optical characterization of the ZnO powders, carried out by UV–vis spectroscopy, showed a strong absorption band centered at 380 nm, which is associated to excitonic transitions in ZnO nanoparticles, whilst absorption measurements of silver nanoparticles colloids revealed the presence of a strong band centered near 412 nm. This band shifts to shorter wavelengths with increasing fluence from 2.6 to 6.2 J cm−2, indicating changes in nanoparticles size. Photocatalytic degradation tests of methylene blue under UV irradiation were carried out using pure ZnO, Ag colloids and Ag/ZnO nanoparticles. After the first 30 min of irradiation, it was observed that the silver nanoparticles reached degradation percentages of 16, 22 and 29% for samples synthesized at 2.6, 4.2 and 6.2 J cm−2, respectively. Meanwhile the ZnO sample reached a value of 13% after 30 min. Regarding the Ag/ZnO composite sample, the percentage of degradation after 30 min was 36%, demonstrating a considerable enhanced photocatalytic activity as compared to ZnO. After 24 h irradiation, Ag/ZnO degraded 95% of the methylene blue solution. It was observed that decorating ZnO with laser produced silver nanoparticles accelerates the photocatalytic response of ZnO by enhancing the activity at short times.

Self‐assembled nanoparticles based on pullulan‐g‐poly(Z‐L‐lysine) for controlled drug delivery: Synthesis, characterization and preliminary studies on the encapsulation of indomethacin

AbstractNovel biocompatible systems suitable for the controlled release of active ingredients are under the spotlight within the last few years. The present investigation focuses on the preparation of nanoparticles (NPs) based on the amphiphilic copolymer pullulan‐graft‐poly(Z‐L‐lysine) bearing different amounts of lysine (10, 20, and 30 wt%), and on the evaluation of their ensuing viability to encapsulate the hydrophobic nonsteroidal anti‐inflammatory drug indomethacin (INDO). The copolymers are synthesized by ring‐opening polymerization, characterized by NMR and FTIR, and their critical aggregation concentration is determined by fluorescence. The NPs are prepared with and without INDO using different copolymer/solvent ratios and INDO/copolymer ratios. The hydrodynamic diameter and polydispersity of the NP suspensions are monitored by dynamic light scattering for 30 days. Their sizes vary between 208 and 338 nm, and some reach the micrometric range (19–73 μm). INDO‐free NPs are identified as spherical‐shaped by atomic force microscopy. Two formulations are tested in terms of encapsulation efficiency (EE = 43%–89%), and the drug crystallinity (DC = 7%–27%) which is determined by differential scanning calorimetry, indicating a reduction with respect to pristine INDO. The results suggest that the copolymers prepared herewith have potential to be applied as carriers for new drug delivery systems of class II drugs.

Investigation of the processes of additional oil displacement by nanosuspension silicon oxide from a model core

The use of nanosuspensions during reservoir flooding is an alternative to chemical methods for enhancing oil recovery. In this work, the effectiveness of using nanosuspensions as a post-displacement agent after the base agent (water) was shown. Filtration tests for additional oil displacement from model rock samples were carried out. Suspensions of nanoparticles were used for post-displacement. The mass concentration of spherical silicon oxide nanoparticles (SiO2) varied from 0.01 to 0.25%wt, and their size varied from 10 to 35 nm. The permeability of the model core was 50 mD. An experimental measurement of the interfacial tension and the contact angle of wettability was performed. It is shown that with an increase in the concentration of nanoparticles, the interfacial tension of the “oil — suspension” decreases. It has been established that at a fixed concentration of nanoparticles (0.1%), with an increase in the size of nanoparticles, the interfacial tension decreases. It was revealed that when using suspensions, the contact angle of rock wetting with oil changes significantly. As a result of filtration tests, dependences of the oil displacement efficiency on the concentration and size of nanoparticles were obtained. It has been shown that additional volume of oil can be recovered after filtering nanosuspensions.

The influence of suspension and deposition on pool boiling heat transfer of nanofluids: Experiment and engineering model study

Currently, the majority of research indicates that nanofluids have superior heat transfer capabilities. On the impact of nanofluids on the boiling heat transfer, there is debate. It is still challenging to predict the boiling heat transfer of nanofluids. Based on bubble behavior, the impact of nanoparticles on boiling heat transfer is investigated in this paper. Furthermore, a comparison is made between the percentages of deposited and suspended nanoparticles that influence on boiling heat transfer. According to the findings, deposited nanoparticles improve wettability whereas suspended nanoparticles diminish it. The number of active nucleate sites and the frequency of bubble detachment increase as a result of the influence of suspended and deposited nanoparticles, whereas the diameter of the bubble decreases. This is similar to the trend of the effect of deposited nanoparticles on bubble behavior. Based on the effect of nanoparticles on wettability, predictive models for boiling heat transfer and bubble behavior were proposed, with a range of mass concentrations between 0.001 % and 0.005 % and heat flux between 60 and 130 kW/m2. Less than 30 % was found to be the error between the experimental data and the predictive equations. It was discovered that the influence of deposited nanoparticles on boiling heat transfer was usually dominant, according to the predictions made by theoretical models.

Suppression of cracking in drying colloidal suspensions with chain-like particles.

The prevention of drying-induced cracking is crucial in maintaining the mechanical integrity and functionality of colloidal deposits and coatings. Despite exploring various approaches, controlling drying-induced cracking remains a subject of great scientific interest and practical importance. By introducing chain-like particles composed of the same material and with comparable size into commonly used colloidal suspensions of spherical silica nanoparticles, we can significantly reduce the cracks formed in dried particle deposits and achieve a fivefold increase in the critical cracking thickness of colloidal silica coatings. The mechanism underlying the crack suppression is attributed to the increased porosity and pore sizes in dried particle deposits containing chain-like particle, which essentially leads to reduction in internal stresses developed during the drying process. Meanwhile, the nanoindentation measurements reveal that colloidal deposits with chain-like particles exhibit a smaller reduction in hardness compared to those reported using other cracking suppression approaches. This work demonstrates a promising technique for preparing colloidal coatings with enhanced crack resistance while maintaining desirable mechanical properties.

Experimental studies on the effect of Al2O3 + water nanofluid concentrations on dimensionless heat transfer parameters in a cleanroom air handling unit

Nanofluid, a colloidal suspension of nonmetallic or metallic nanoparticles into conventional base fluid and used for heat transfer characteristics enhancement for many industrial applications. Cleanrooms are essential at various industries for controlling airborne contamination and environmental parameters. In this article, heat transfer properties of nanofluid (Al2O3 + water) at various nanoparticle concentrations (1%, 2%, and 3%) on a prototype cleanroom air handling chiller unit was investigated experimentally in laminar flow zone. Thermal conductivity ratio, Nusselt number, Peclet number, and pressure drop were obtained for above nanoparticle concentrations. Experimental investigations indicate the heat transfer properties improvement in a prototype cleanroom air handling chiller unit by using nanoparticle at base fluid. Experimental investigation on varying Al2O3 + water nanofluid concentrations in a cleanroom air handling chiller unit heat exchanger revealed a notable increase in heat transfer by reducing nanoparticle size from 50 to 10 nm and increasing concentration from 1% to 3% volume, resulting in a 17.70% rise in thermal conductivity ratio and a significant 9.23% increase in Nusselt number at higher Peclet numbers. However, this improvement in heat transfer was accompanied by a substantial 72.5% increase in pressure drops, particularly with increased Reynolds number and particle concentration. Manipulating nanoparticle characteristics resulted in substantial improvements in Nusselt number across a wide range of Reynolds numbers, with smaller particle sizes and higher volume concentrations yielding more significant heat transfer improvements. The novelty of this research lies in its investigation of the influence of variable Al2O3 + water nanofluid concentrations, encompassing different nanoparticle sizes, and volume concentrations, on dimensionless heat transfer parameters within a cleanroom air handling unit, offering valuable insights into optimizing heat transfer efficiency in a controlled and critical environment, addressing a significant research gap in the field.

Enhancing thermal performance in enclosures filled with nanofluids subjected to sinusoidal heating: a numerical study

ABSTRACT This study conducts a comprehensive numerical investigation into enhancing thermal transfer within square enclosures filled with water-based oxide nanoparticle suspensions, subjected to central sinusoidal heating. Further flow configuration, influenced by an inclined magnetic field, is designed with a focus on enhancing thermal efficiency for engineering applications. Key innovations include the application of sinusoidal heating elements to enhance thermal performance significantly. Computational analysis supported by finite element analysis, quantifies the impact of these parameters on flow dynamics and thermal transmission, presenting a substantial advance in the understanding of nanofluid-filled enclosure thermal management. The study reveals that the undulation of the heating element plays a crucial role in the heat transfer rate, with improvements observed as undulation increases. The introduction of magnetic fields further controls flow distribution and buoyancy effects, as demonstrated by our findings that an increase in the Rayleigh number correlates with enhanced convection, dominating the cavity's thermal dynamics. Additionally, the report outlines the conditions under which the Nusselt number increases, indicating enhanced thermal performance. These insights are pivotal for designing optimized heat transfer systems and energy-efficient applications, setting a new benchmark for thermal management strategies in practical engineering contexts.

Thermohydrodynamics of Bödewadt hybrid-nanofluid flow in a horizontal magnetic field

Since disks, rotating or stationary, are integral in many thermal systems, such as rotating heat exchangers, thermoelectric coolers, solar energy systems, and geothermal plants, this study scrutinizes the thermohydrodynamics of rotating hybrid nanofluid flow over a stretchable disk at rest. Further, the shape of the nanoparticles and the choice of base fluid substantially impact the enhancement of the heat transfer rate in various such thermal systems. Therefore, the present investigation considers engineered colloids made of four distinct (sphere, cylinder, column, lamina) titania and copper nanoparticle shapes in two different base fluids: water and engine-oil. The problem is formulated mathematically in an externally applied horizontal magnetic field and incorporating a non-Fourier heat flux model in the presence of solar radiation. Analogous to the case of the conventional vertical magnetic field, a similarity solution is also possible when magnetic forces act horizontally, both towards and opposite to the direction of rotation. Thus, the governing partial differential equations (PDEs) are first reduced to a set of highly non-linear and coupled ordinary differential equations (ODEs) via similarity transformations. These resulting set of ODEs are then solved numerically using a rapid and efficient spectral quasilinearization method (SQLM). Obtained results show that lamina-shaped TiO2−Cu/ engine-oil hybrid-nanofluid is a better choice than the other shapes of nanoparticle suspension in water. The horizontally applied magnetic field exhibits a stronger influence on the flow and heat transfer characteristics when compared to a vertical magnetic field. Additionally increasing the thermal relaxation parameter αt from 0.1 to 0.35, the Nusselt number boost by 24.44%, 23.41%, 22.54%, and 17.93% for sphere, cylinder, column, and lamina nanoparticles of TiO2−Cu/water hybrid nanofluid. In the case of TiO2−Cu/engine-oil hybrid-nanofluid augmenting αt from 0.1 to 0.35, the Nusselt number rise by 23.95%, 22.83%, 21.82%, and 15.89% for sphere, cylinder, column, and lamina nanoparticles. Based on their increasing NS and Be values, the various shapes follow the sequence: lamina ¡ column ¡ cylinder ¡ sphere. Furthermore, entropy generation can be optimized through the augmentation of solar radiation factors QSR, δ, along with the reduction of the magnetic interaction parameter M, and by a proper selection of nanoparticle’s shape. Interestingly, dual solutions are observed for the case of a shrinking disk, i.e., for S<0, and a linear temporal stability analysis reveals that only one of these two branches, namely the first solution branch, is stable and the second branch unstable.

The significant role of Darcy–Forchhiemer with integrated hybrid nanoparticles (Graphene and TiO 2) on dusty nanofluid flow subjected to heat conduction

The thermal analysis of two-phase models that deal with the fluid and dusty phases has been considered. This study instigates the flow of a non-miscible, dusty hybrid nanofluid over a stretching cylinder with Darcy–Forchheimer permeability in the presence of thermal radiation. The mathematical model is based on the single-phase nanofluid model, which features modified thermophysical characteristics. This innovative flow model explores how important it is to enhance the concentration of dust particles in fluid dynamics. Hybrid nanoparticles are substituted for nanoparticles in a conventional case to accelerate the heat transfer rate of the fluid. Therefore, in this study, the magnetohydrodynamic flow of hybrid nanofluids and heat transfer of non-Newtonian dusty fluids with suspensions of hybrid nanoparticles have been examined. The appropriate dimensionless variables are used to convert the governing periodic model into a non-dimensional form. The finite-difference-based bvp5c algorithm is used through Matlab for numerical analysis of the set of obtained ordinary differential equations. The graphs explored the influences of relatable factors over the profiles of mass, heat, and velocity transfers. It is observed that with intensifying values of Eckert number (Ec) and Biot number (Bi), the temperature of both phases increased at a significant level, and the velocity decreased with increasing intensity of the magnetic field. The computational results of velocity, core temperature, and intensity dispersion are significant for both aspects. Furthermore, it is observed that both the fluid and dust phases exhibit declining behavior as a result of the impact of porosity, mass concentration, and magnetism on the flow stream. Moreover, it is noticed that both the dust phase temperature θ p ( η ) and fluid phase temperature θ ( η ) intensified with the high intensity of magnetic field and thermal radiation. The missile nozzles, nuclear power plants for aerospace and gaseous-core nuclear rocket systems, and the radiation are considered for evaluating heating significance.

Novel surface modification strategies for enhanced CeO2 nanoparticle dispersion and suspension stability

This work aims to modify the surface characteristics of cerium oxide (ceria, CeO2) nanoparticles using different surface modification strategies for improved CeO2 nanoparticle dispersion and suspension stability. Analysis and discussion were conducted on the two surface modification processes used by a cationic surfactant like hexadecyl cetyltrimethylammonium bromide (CTAB) and a silane agent like tetraethyl orthosilicate (TEOS). Untreated CeO2 was used as reference material. The dispersion effect of surface-modified CeO2 nanoparticles at different pHs was determined by zeta potential measurements. Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Particle size analysis (PSA), Thermogravimetric analysis (TGA), Scanning electron microscope (SEM), Brunauer–Emmett–Teller analysis (BET), and X-ray diffraction (XRD) were used to confirm the efficacy of the surface modification of CeO2 nanoparticles. First, the results obtained in this experimental work demonstrate that both advanced modifications greatly enhance the dispersion and suspension stability of surface-modified CeO2 nanoparticles in comparison with untreated CeO2 nanoparticles. Second, it is also shown that the surface-modified CeO2 nanoparticles obtained through a silanization surface process with TEOS silane agent had a better dispersion effect and dispersion stability than the surface-modified CeO2 nanoparticles obtained by surface modification with CTAB cationic surfactant. These results can help better understand how advanced surface modifications can assist the application of well-dispersed CeO2 nanoparticles in technological applications.

Inelastic X-ray Scattering as a Probe of Terahertz Phonon Propagation in Nanoparticle Suspensions

Inelastic X-ray Scattering as a Probe of Terahertz Phonon Propagation in Nanoparticle Suspensions

Improving heat transfer through alumina-silica nanoparticles suspension: an experimental study on a single cooling plate

ABSTRACT The urge for more complicated, sophisticated electrically active heat transfer devices, has intensified nowadays thus requiring a more critical thermal management issue. The generation of higher heat flux needs to be tackled efficiently as to avoid performance deterioration to the devices. The conventional active heat transfer method alone has limitations, especially in terms of space. This paper studies the effect of Al2O3:SiO2 hybrid nanofluids with 0.5% volume concentration in water as an alternative coolant in a single cooling plate. Five different ratios of hybrid Al2O3:SiO2 nanofluids were investigated ranging from 10:90 to 50:50 (Al2O3:SiO2) mixture ratio. Two types of cooling plates were studied which were Serpentine and Distributor type cooling plates. These plates were fabricated from carbon graphite which is commonly used in a liquid-cooled Proton Exchange Membrane Fuel Cell (PEMFC). In conclusion, the R1 (10:90) Al2O3:SiO2 hybrid nanofluids were shown as the most prominent ratio in heat transfer improvement and Serpentine shows the most feasible cooling plate with higher convective heat transfer and lower pumping power than the Distributor plate.

Abstract LB024: Permeation enhancer is necessary for the optimized PRV131 mediated cisplatin intratumoral delivery

Abstract PRV131 is an effective and safe polymeric nanoparticle suspension for intratumoral cisplatin delivery. Background: Systemic administration of platinum-based chemotherapy often leads to dose-limiting toxicity, affecting quality of life. While intratumoral delivery may reduce or eliminate the systemic toxicities and adverse side effects associated with intravenous cisplatin chemotherapy, this approach is not commonly adopted, in part due to the difficulty to obtain high drug retention in the tumor and control sustained drug release. PRV131 is a highly-concentrated cisplatin polymeric nanoparticle suspension carefully designed for intratumoral administration. The goal of this study was to assess the safety and efficacy of PRV131 as a monotherapy and in combination with a checkpoint inhibitor in a well-established preclinical murine colorectal adenocarcinoma model. Experimental Methods: MC38 cells were inoculated subcutaneously into the flanks of C57BL/6J female mice and allowed to grow to an average size of 100 mm3. Mice were then randomized into 6 groups of n=10: control (saline injection), 100 µg of cisplatin solution, 400 µg of cisplatin solution, 400 µg of PRV131, 400 µg of PRV131 + 200 µg systemic anti-PD1, and 200 µg systemic anti-PD1. A single injection of PRV131 or cisplatin solution was administered directly into the tumor on Day 1. Intraperitoneal anti-PD-1 was administered on Day 1 and Day 10. Mice were then monitored for efficacy (tumor measurements) and safety (overall health, weight loss and mortality). The durability of a single PRV131 injection was also studied. Efficacy and safety were adjudicated at 28 days post treatment and treatment durability assessment extended through 60 days post inoculation. Results: Our data demonstrates that PRV131 400 µg was significantly more effective than cisplatin solution at an equivalent dose. 80% of PRV131 treated mice survived to day 60 post inoculation, and no detectable tumor was found in 60% of PRV131 treated mice 38 days post administration. The safety profile was acceptable, with no mouse lost more than 20% body weight. Notably, efficacy profile of PRV131 monotherapy did not differ substantially from the addition of anti-PD-1 to the treatment, suggesting a high translational relevance of our drug delivery platform. Conclusion: A single intratumoral injection of PRV131 is well-tolerated in C57BL/6J female mice and elicits a durable antitumor response that lasts for over 30 days, laying the groundwork for its incorporation in clinical trial setting. Citation Format: Manijeh Goldberg, Aaron Manzi, Stefanie Cantin, Peter Conway, Jonathan Shikora, Adelaide McFarland, Matt Cayer, Lillyanna Dunn, Courtney Ball, Alexander T. Pearson, Ari J. Rosenberg, Nishant Agrawal, Evgeny Izumchenko. Permeation enhancer is necessary for the optimized PRV131 mediated cisplatin intratumoral delivery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB024.

Abstract LB440: PRV131 is an effective and safe polymeric nanoparticle suspension for intratumoral cisplatin delivery

Abstract Background: Systemic administration of platinum-based chemotherapy often leads to dose-limiting toxicity, affecting quality of life. While intratumoral delivery may reduce or eliminate the systemic toxicities and adverse side effects associated with intravenous cisplatin chemotherapy, this approach is not commonly adopted, in part due to the difficulty to obtain high drug retention in the tumor and control sustained drug release. PRV131 is a highly-concentrated cisplatin polymeric nanoparticle suspension carefully designed for intratumoral administration. The goal of this study was to assess the safety and efficacy of PRV131 as a monotherapy and in combination with a checkpoint inhibitor in a well-established preclinical murine colorectal adenocarcinoma model. Experimental Methods: MC38 cells were inoculated subcutaneously into the flanks of C57BL/6J female mice and allowed to grow to an average size of 100 mm3. Mice were then randomized into 6 groups of n=10: control (saline injection), 100 µg of cisplatin solution, 400 µg of cisplatin solution, 400 µg of PRV131, 400 µg of PRV131 + 200 µg systemic anti-PD1, and 200 µg systemic anti-PD1. A single injection of PRV131 or cisplatin solution was administered directly into the tumor on Day 1. Intraperitoneal anti-PD-1 was administered on Day 1 and Day 10. Mice were then monitored for efficacy (tumor measurements) and safety (overall health, weight loss and mortality). The durability of a single PRV131 injection was also studied. Efficacy and safety were adjudicated at 28 days post treatment and treatment durability assessment extended through 60 days post inoculation. Results: Our data demonstrates that PRV131 400 µg was significantly more effective than cisplatin solution at an equivalent dose. 80% of PRV131 treated mice survived to day 60 post inoculation, and no detectable tumor was found in 60% of PRV131 treated mice 38 days post administration. The safety profile was acceptable, with no mouse lost more than 20% body weight. Notably, efficacy profile of PRV131 monotherapy did not differ substantially from the addition of anti-PD-1 to the treatment, suggesting a high translational relevance of our drug delivery platform. Conclusion: A single intratumoral injection of PRV131 is well-tolerated in C57BL/6J female mice and elicits a durable antitumor response that lasts for over 30 days, laying the groundwork for its incorporation in clinical trial setting. Citation Format: Manijeh Goldberg, Aaron Manzi, Stefanie Cantin, Peter Conway, Jonathan Shikora, Adelaide McFarland, Matt Cayer, Lillyanna Dunn, Courtney Ball, Alexander T. Pearson, Ari J. Rosenberg, Nishant Agrawal, Evgeny Izumchenko. PRV131 is an effective and safe polymeric nanoparticle suspension for intratumoral cisplatin delivery [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB440.

Superparamagnetic effects in the linear magnetic response of polydisperse ensembles of nanoparticles suspended in a fluid.

Within a kinetic theory, the linear magnetic response of uniaxial single-domain particles suspended in a fluid is analyzed. The main qualitatively different types of frequency dependence of the longitudinal dynamic magnetic susceptibility of such particles are described. It is shown that superparamagnetic (related to orientation thermal fluctuations of the magnetic moment inside a particle) peculiarities of the response of a particle to a probing magnetic field are not fully determined by the ratio of anisotropy energy to thermal energy when a stationary bias field is applied. For a case where the indicated ratio is much greater than one, a simple approximate expression for the dynamic magnetic susceptibility of a particle is proposed. The developed approach is extended to polydisperse suspensions of noninteracting uniaxial nanoparticles. It is shown that polydispersity does not vanish away specific superparamagnetic features in the dynamic magnetic response of such systems. Quantitative estimates of the corresponding effects are performed in different frequency ranges of the applied field. It is demonstrated that under certain restrictions on the disperse composition of a suspension, the internal diffusion of the magnetic moment can lead to a splitting of the absorption spectrum of the system. The significant role of the bias field is revealed. In particular, it can cause an additional absorption maximum provided the particle-size distribution meets the outlined condition. Also, it enables one to assess how important it is to take into account superparamagnetism of particles: the effect of the biasing is stronger for particles with smaller anisotropy and thereby more pronounced superparamagnetic properties. A qualitative agreement of some of the inferences with the experimental data is briefly discussed.