Binary Colloids Research Articles

Abstract 7494: Pan-cancer analysis of circulating tumor organoid drug sensitivity revealed differential distribution of viability dependence among cancer hallmark modules

Abstract Background: Patient-derived organoids represent an opportunity into deciphering human cancer biology at the personal-level resolution. Phenotyping living cell properties, such as drug sensitivity, complements deep sequencing to improve the prediction of cancer treatment response and holds promises for functional precision medicine. Modern cancer therapeutics target genetic alterations in modular networks, also known as cancer hallmarks, which drive biological essentialities for cancer progression. However, it remains elusive the relative robustness of each module among the naturally occurring solid tumors. Methods: In order to explore this issue, we analyzed a drug sensitivity database of a collection of circulating tumor cells-derived organoids (CDO) from 532 patients with advanced/metastatic solid tumors to 15 chemicals. In this collection, each CDO was derived from 20 ml peripheral blood on a binary colloid crystal cell culture system over 4 weeks. CDO were tested for survival fraction at the Cmax of the designated chemicals. Cell viability was measured with ATP abundance normalized to vehicle controls. For each chemical tested, the probability density function (PDF) of drug sensitivity was fitted to log normal distribution and goodness of fit was analyzed with Kolmogorov Smirnov test with the significance cut-off set to 0.05. The targeted biological pathway of each chemical was mapped to canonical human pathways in the Gene Ontology and KEGG databases. Strength of the specific evolution conserved module (ECM) was evaluated with the published analysis using clustering by inferred models of evolution (CLIME) algorithm. Results: There were 25 types of tumors in the database. The top 3 tumor types were soft-tissue sarcoma, breast cancers, central nervous system tumor. The average number in each tumor type was 21. The PDF of commonly known chemotherapeutic agents, such as gemcitabine, doxorubicin, docetaxel followed log normal distribution. In contrast, the PDF of commonly known biological targeted agents such as everolimus, cabozantinib or enzalutamide do not. For chemicals whose PDF followed a log normal distribution, the biological pathways that were affected tend to have a higher strength of ECM value. Conclusions: Our early analysis revealed the feasibility to quantitatively estimate the robustness of biological pathways in the cancer hallmark modules with a CDO bank. The biological implication of deviation from classical log normal distribution for biologically targeted agents warrants further investigation. Citation Format: Yihsuan Chen, Shih-Pei Wu, Yin-Ju Chen, Long-Sheng Lu. Pan-cancer analysis of circulating tumor organoid drug sensitivity revealed differential distribution of viability dependence among cancer hallmark modules [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7494.

Stability of binary colloidal mixtures of Au noble metal and ZnS semiconductor nanoparticles

Controlling the stability of colloidal nanoparticles in multicomponent systems, i.e., mixtures of colloids, is of vital importance for product formulations and separation processes of nanoparticles. However, very few studies are currently found in literature regarding the generation of binary colloids by mixing of colloidal nanoparticles, particularly small nanoparticles (< 20 nm). In this study, we report on the development of a stable binary colloid made of nanoparticles of different sizes and compositions. As a model system for this study, we mixed aqueous dispersions of gold nanoparticles (Au NPs) and ZnS quantum dots (QDs). We investigated the stability of Au NPs with three different surface ligands after mixing them with ZnS QDs, both before and after functionalization of the Au NPs with bis(p-sulfonatophenyl) phenylphosphine (BSPP). We used UV–visible spectroscopy as the primary method to monitor stability of nanoparticles in the binary mixture over time. We found out that the released thioglycerol and acetate from the surface of ZnS QDs to the binary mixture induces agglomeration in Au NPs. The surface chemistry and the purification process of Au NPs after their synthesis and surface treatment were identified as key parameters to regulate the stability in the mixture. Thus, we successfully achieved a stable mixture of BSPP-functionalized Au NPs with ZnS QDs as a model of a stable binary mixture. We believe that this study is important to stimulate research directed towards real-world multicomponent formulations including their characterization and the understanding of surface interactions.

Rigidity-Induced Controlled Aggregation of Binary Colloids.

Here, we report the proof-of-concept for controlled aggregation in a binary colloidal system. The binary systems are studied by varying bond flexibility of only one species, while the other species' bonds remain fully flexible. By establishing the underlying relation between gelation and bond rigidity, we demonstrate how the interplay among bond flexibility, critical concentration, and packing volume fraction influenced the aggregation kinetics. Our result shows that rigidity in bonds increases the critical concentration for gels to be formed in the binary mixture. Furthermore, the average number of bonded neighbor analyses reveal the influence of bond rigidity both above and below critical concentrations and show that variation in bond flexibility in only one species alters the kinetics of aggregation of both species. This finding improves our understanding of colloidal aggregation in soft and biological systems.

Structural Color Mixing in Microcapsules through Exclusive Crystallization of Binary and Ternary Colloids.

Colloidal crystals are designed as photonic microparticles for various applications. However, conventional microparticles generally have only one stopband from a single lattice constant, which restricts the range of colors and optical codes available. Here, photonic microcapsules are created that contain two or three distinct crystalline grains, resulting in dual or triple stopbands that offer a wider range of colors through structural color mixing. To produce distinct colloidal crystallites from binary or ternary colloidal mixtures, the interparticle interaction is manipulated using depletion forces in double-emulsion droplets. Aqueous dispersions of binary or ternary colloidal mixtures in the innermost droplet are gently concentrated in the presence of a depletant and salt by imposing hypertonic conditions. Different-sized particles crystallize into their own crystals rather than forming random glassy alloys to minimize free energy. The average size of the crystalline grains can be adjusted with osmotic pressure, and the relative ratio of distinct grains can be controlled with the mixing ratio of particles. The resulting microcapsules with small grains and high surface coverage are almost optically isotropic and exhibit highly-saturated mixed structural colors and multiple reflectance peaks. The mixed color and reflectance spectrum are controllable with the selection of particle sizes and mixing ratios.

Nanocomposite of binary colloids in effective CO2 utilization in porous media for enhanced oil production and wettability alteration

Carbon dioxide injection is a renowned enhanced oil recovery method, where the inclusion of a novel material is appreciated via mobility control of injected CO2 during flow through porous and permeable oil reservoirs. Therefore, the combination of nanoparticles and their associated additives is recommended for foam flooding schemes. Thus, this study reports the use of nanocomposites of SiO2 (0.1 – 2 wt%) and TiO2 (0.1 wt%) in promoting CO2 utilization in oil recovery projects. The assessment of a foam emulsion is a crucial and interesting task to understand the basic fundamental of three-phase interactions viz., Crude oil (oil phase), nanocomposites (aqueous phase), and CO2 (gas phase) in the context of foam-emulsion, and was examined via microscopic and rheological characterization. CO2 foam showed temperature tolerance capability and a shear-thinning viscoelastic nature due to the inclusion of nanocomposites. Furthermore, wettability alteration was understood via contact angle measurements between CO2 and nanocomposite. Interestingly, the contact angle was reduced to 39° after the inclusion of 0.1 wt% TiO2 and CO2 in the system. Finally, nanocomposite stabilized CO2 foam demonstrated a total cumulative oil recovery of 78 % at (40 °C), higher than the cumulative oil recovery (70 %) associated with nanocomposite without CO2. The results of this study suggest that CO2 utilization for oil recovery can be enhanced by developing its viscous foam, stabilized by a nanocomposite of SiO2 and TiO2 nanoparticles.

Treatment response prediction with circulating tumor cell-derived organoids for soft tissue sarcoma.

e23521 Background: Pharmacologic treatment for soft tissue sarcoma (STS) remains challenging. There is a lack to predict treatment responses to chemotherapy or targeted therapy to oncologic drivers. We hypothesize that circulating tumor cells may enrich cancer initiating cells and represent a window to probe personalized drug treatment response. In this study, we test if drug sensitivity profile of short-term culture of tumor organoids derived from circulating tumor cells (CTCs) correlates to clinical treatment response. Methods: From April 2019 to December 2020, 50 patients with biopsy-confirmed STS, who had either recurrent or metastatic tumors, were enrolled in a prospective observational study in Taipei Medical University Hospital. The median age of the patients was 47, and the top 3 diagnoses were leiomyosarcoma, aggressive fibromatosis and rhabdomyosarcoma. 74% of patients had metastatic diseases at the time of blood collection. Fifty-five blood samples were collected and processed for CTC organoid culture and drug sensitivity analysis (EVASelect, CancerFree Biotech, Taipei, Taiwan), which involves culturing nucleated blood cells on a binary colloid crystal-coated surface. Clinical response was evaluated using RECIST criteria 3 months after blood collection. The relationship between CTC viability and clinical response was analyzed using a contingency table and Chi-square analysis. Results: The success rate of CTC expansion was 87.2% (48/55), as defined by ATP abundance higher than 3000 U2OS cells after 18 days of culture. Clinical information from 32 of the 50 cases was eligible for analysis, and the results showed that CTC viability at a 70% cutoff correlated with clinical disease control at 3 months after blood collection. The odds ratio, sensitivity, specificity, and diagnostic accuracy were 12 (p = 0.036), 92.3%, 50%, and 79%, respectively. A demonstration of the interaction between this research and the Molecular Tumor Board (MTB) in the Taipei Medical University Healthcare System is presented through a case study of metastatic angiosarcoma and its correlation. Conclusions: The study highlights the potential of using CTC drug sensitivity as a biomarker for precision medicine in STS, despite limitations such as small sample size, short follow-up, and disease and treatment heterogeneity. Advancements in gene-based precision medicine have been made in the past decade, but only a small number of STS patients have seen benefits from it. This emphasizes the need for further research to thoroughly evaluate the potential of CTC drug sensitivity as a predictive biomarker in clinical practice. Key words: soft tissue sarcoma; circulating tumor cells; liquid biopsy; predictive biomarker; precision medicine.

High density deposits of binary colloids

Colloids are essential materials for modern inkjet printing and coating technology. For printing and coating, it is desirable to have a high density of colloids with uniformity. Binary colloids, which consist of different size colloidal particles, have the potential to achieve high coating density and uniformity from size effects. We report a strategy to attain high-density deposits of binary colloids with uniform, crack-free, and symmetric deposits through droplet evaporation on micropillar arrays. We modify surfaces of micropillar arrays with plasma treatment to control their surface energy and investigate how binary colloidal fluids turn into well-controlled deposits during evaporation with X-ray microscopic and tomographic characterizations. We attribute temporary surface energy modification of micropillar arrays to the well-controlled high-density final deposits. This simple, low-cost, and scalable strategy would provide a viable way to get high-quality, high-density deposits of colloids for various applications.

Adsorption Races of Binary Colloids with Different Softness at the Air/Water Interface of Sessile Droplets (Adv. Mater. Interfaces 28/2022)

Adsorption Races of Binary Colloids The surface modification of colloidal particles by soft hydrogels provides a means to control the adsorption behavior at the air/water interface of sessile droplets. Especially binary mixtures of such particles exhibit unique adsorption behavior that manifests in adsorption races to the interface, resulting in the micro-pattern formation of binary particles as well as in a suppression of the coffee-ring effect. This is reported by Daisuke Suzuki and co-workers in article number 2200879.

Adsorption Races of Binary Colloids with Different Softness at the Air/Water Interface of Sessile Droplets

AbstractAlthough methods to suppress macroscopic nonuniform structures, e.g., due to the coffee‐ring effect, have been established, the formation of specific patterns during the evaporation of water from sessile droplets that contain colloidal particles remains challenging. In this study, it is discovered that the surface modification of colloidal particles by soft hydrogels provides a means to control the adsorption kinetics on the air/water interface. Especially binary mixtures of such core/shell colloids exhibit unique adsorption behavior that manifests in adsorption races to the interface, resulting in the formation of patterns of binary colloidal particles as well as in a suppression of the coffee‐ring effect. These results can be expected to be beneficial for applications such as inkjet coating, where the required micro‐patterns are controlled via the evaporation of solvents.

Self-Organization of Binary Colloidal Mixtures via Diffusiophoresis.

Catalytic activity of the colloids and chemotactic response to gradients of the chemicals in the solution leads to effective interaction between catalytic colloids. In this paper, we simulate mixtures of active and passive colloids via a Brownian dynamics algorithm. These particles interact via phoretic interactions, which are determined by two independent parameters, surface activity and surface mobility. We find rich dynamic structures by tuning passive colloids’ surface mobility, size, and area fractions, which include schools of active colloids with exclusion zone, yolk/shell cluster, and stable active–passive alloys to motile clusters. Dynamical cluster can also be formed due to the nonreciprocity of the phoretic interaction. Increasing the size ratio of passive colloids to active colloids favors the phase separation of active and passive colloids, resulting in yolk/shell structure. Increasing the area fraction of active colloids tends to transfer from dynamical clusters into stable alloys. The simulated binary active colloid systems exhibit intriguing nonequilibrium phenomena that mimic the dynamic organizations of active/passive systems.

Self-assembly and percolation in two dimensional binary magnetic colloids.

We study the self-assembly of branching-chain networks and crystals in a binary colloidal system with tunable interactions. The particle positions are extracted from microscopy images and order parameters are extracted by image processing and statistical analysis. With these, we construct phase diagrams with respect to particle density, ratio and interaction. In order to draw a more complete picture, we complement the experiments with computer simulations. We establish a region in the phase diagram, where bead ratios and interactions are symmetric, promoting percolated structures.

Depletion Induced Demixing and Crystallization in Binary Colloids Subjected to an External Potential Barrier.

Depletion interaction plays an important role in determining the structural and dynamical properties of binary colloidal mixtures. We have investigated the effect of the attractive depletion interaction between an external potential barrier and larger species in the binary mixture on the phase behavior of a binary colloidal mixture using canonical-isokinetic ensemble molecular dynamics simulations. The demixing of the binary mixture due to this depletion interaction increases as the volume fraction increases, and a pure phase of larger particles forms in the region of the potential barrier. The local density of this pure phase is high enough that a face centered cubic crystalline domain is formed at this region. This crystalline phase diffuses perpendicular to the external potential barrier, indicating that moving crystals can be obtained in an equilibrium system. The temperature dependence of diffusivity of larger particles is non-Arrhenius and changes from sub-Arrhenius to super-Arrhenius as the volume fraction increases. This crossover from sub-Arrhenius to super-Arrhenius diffusion coincides with the crystalline formation near the potential barrier.

Particle dynamics in drying colloidal solution using discrete particle method

We study particle dynamics in drying colloidal solutions using the numerical simulation with discrete particle method. Simulations of two different systems were conducted; the drying dynamics of monodispersed and binary mixture of colloidal solution, and compared with those from the previous studies. In the monodispersed colloidal solution, the time evolution of particle concentration profile for varying Péclet number was simulated with the same initial particle concentration. In the binary colloidal solution, when the particle size ratio is 3, three different stratification modes were observed varying Péclet number and initial particle concentration. By comparison, our method was in a good agreement with the existing methods. Additionally, because of the mesh-based Eulerian approach in our model, other various multi-physical phenomena, such as effect of thermal Marangoni or chemical reaction, can be included in an easy way. From the results, we expect that this work can provide a physical insight for predicting the quality of colloidal drying in a complicated situation.

Translation-rotation decoupling of tracers reflects medium-range crystalline order in two-dimensional colloid glasses.

The dynamic heterogeneity and the translation-rotation decoupling are the dynamic signatures of glasses and supercooled liquids. Whether and how the dynamic heterogeneity would relate to the local structure of glasses has been a puzzle for decades. In this work we perform molecular dynamics simulations for tracers in both two-dimensional polydisperse colloids (2DPC) and two-dimensional binary colloids (2DBC). In 2DPC glasses, hexatic local structures develop at low enough temperatures and grow quickly along with the dynamic correlation length of the 2DPC, which is well known as the medium-range crystalline order (MRCO). In 2DBC glasses, on the other hand, any explicit local structure has not been reported to grow significantly with the dynamic correlation length at low temperatures. We introduce two different types of tracers into colloidal systems: A diamond tracer that resembles the MRCO of 2DPC glasses and a square tracer that is dissimilar to any local structure of glasses. The translation-rotation decoupling of the diamond tracer in 2DPC glasses is much more significant than that of the square tracer in the same 2DPC glasses. On the other hand, such a tracer shape-dependence of the decoupling is not observed in 2DBC glasses where the local hexatic structure does not develop significantly. We introduce a shape-dependency parameter of the decoupling and find that the shape-dependency parameter grows along with the dynamic correlation length in 2DPC glasses but not in 2DBC glasses. This illustrates that the dynamic heterogeneity and the translation-rotation decoupling of tracers could reveal the local structure that develops in glasses.

Cooperative Electric Alignment of Colloidal Graphene Oxide Particles with Liquid Crystalline Niobate Nanosheets

Abstract Binary colloids of two morphologically different particle species cause phase separation containing liquid crystalline phases. Although electric alignment of colloidal nanosheets has been investigated for colloidal systems consisting of single nanosheet species, that of binary nanosheet colloids has scarcely been examined. We report herein the electric alignment of aqueous binary colloids composed of niobate (NB) nanosheets from K4Nb6O17 and commercially available graphene oxide (GO) platelets. The NB–GO binary colloids show multiphase coexistence involving liquid crystalline phases induced by the NB nanosheets, whereas the employed GO particles do not contribute to the liquid crystallinity. The NB nanosheets in the binary colloids are electrically aligned in parallel to an AC voltage (1 kV cm−1 peak to peak, 50 kHz) applied to the sample. When the concentration of GO in the binary colloids is low enough, the GO particles are also electrically aligned although they hardly respond to electric field in the absence of NB nanosheets. Combined optical microscopy of bright-field, polarized, and fluorescence observations demonstrates that isolated GO particles are dragged by the aligning motion of the NB nanosheets forming liquid crystalline domains. The results indicate that collective motions of colloidal nanosheets can induce participation of isolated particles.

High performance carbon dioxide foams of nanocomposites of binary colloids for effective carbon utilization in enhanced oil recovery applications

Most of conventional carbon dioxide (CO2) foams show limitations in practical applications due to several issues such as thermal stability, disintegration of bubble, dissolution of lamella, and deterioration of rheological property. However, stability of these foams can be improved by including a nanomaterial that makes them stable via Pickering stabilization. Homo-agglomeration, causing large size aggregates, is an important issue with colloidal formulations which reduces foam efficacy due to unsuccessful nanoparticle (NP) adsorption on CO2 surface. Therefore, this study reports the use of nanocomposite of binary NPs (SiO2 and TiO2) in stabilizing CO2 foams at moderate pressure (70 bar) and temperature (90 °C) conditions, to find their use in oilfield practices. CO2 foam stabilized by nanocomposites was studied for thermal stability using microscopic and rheological analysis at 70 bar/90 °C followed by UV–vis and contact angle tests to investigate colloidal interaction with CO2. TiO2 inclusion resulted into remarkable changes in the thermal stability and rheological behavior of SF foam by delaying the process of CO2 coalescence. In addition, the study suggests that TiO2 NP reduces the size of foam bubble through enhanced adsorption as demonstrated by lamella formation and that foam (STF-3, 0.5 wt% SiO2 + 0.1 wt% TiO2) showed least dependency on varying shear, pressure, and temperature conditions. Moreover, the rheological properties such as viscosity and viscoelastic nature of CO2 foams, stabilized by these nanocomposites, show potential for real field applications. Thus, the proposed study highlights the important mechanism of CO2 foam of binary NP system (nanocomposites) followed by rheological analysis of CO2 foam at real conditions, which is useful for CO2 based oil recovery applications.

Effect of Synergistic Aging on Bauxite Residue Dust Reduction Performance via the Application of Colloids, an Orthogonal Design-Based Study.

The application of polymer colloids is a promising approach for bauxite residue dust pollution control. However, due to the existence of synergistic aging, the efficiency of colloid dynamic viscosity to predict the dust control performance of bauxite residue is unclear. Previous studies were also rarely performed under synergistic aging conditions. Thus, this paper investigates the relationship between colloids’ viscosity and dust control performance under synergistic aging modes. Results illustrated that the binary colloid achieved better dust control performance than unitary colloid for their higher viscosity and penetration resistance. For both unitary and binary colloid, higher viscosity results in better crust strength. A logarithmic relationship was found for viscosity and dust erosion resistance under unitary aging. However, Only the dynamic viscosity of colloids in solid-liquid two-phase conditions, rather than dissolved in deionized water, can effectively predict the dust control performance under synergistic aging conditions.

Electrically Induced Alignment of Semiconductor Nanosheets in Niobate-Clay Binary Nanosheet Colloids toward Significantly Enhanced Photocatalysis.

Aqueous binary colloids of niobate and clay nanosheets, prepared by the exfoliation of their mother layered crystals, are unique colloidal systems characterized by the separation of niobate and clay nanosheet phases, where niobate nanosheets form liquid crystalline domains with the size of several tens of micrometers among isotropically dispersed clay nanosheets. The binary colloids show unusual photocatalytic reactions because of the spatial separation of photocatalytically active niobate and photochemically inert clay nanosheets. The present study shows structural conversion of the binary colloids with an external electric field, resulting in the onsite alignment of colloidal nanosheets to improve the photocatalytic performance of the system. The colloidal structure is reshaped by the growth of liquid crystalline domains of photocatalytic niobate nanosheets and by their electric alignment. Niobate nanosheets are assembled by the domain growth process and then aligned by AC voltage, although clay nanosheets do not respond to the electric field. Photocatalytic decomposition of the cationic rhodamine 6G dye, which is selectively adsorbed on clay nanosheets, is examined for the niobate-clay binary nanosheet colloids with or without domain growth and electric field. The fastest decomposition is observed for the electrically aligned colloid without the domain growth, whereas the sample with the domain growth and without the electric alignment shows the slowest decomposition. The results demonstrate the improvement of the photocatalytic performance by changing the colloidal structure, even though the sample composition is the same.

Phase behavior and percolation in mixed patchy colloids.

Patchy colloids can be modeled as hard spheres with directional conical association sites. A variety of physical phenomena have been discovered in the patchy colloid system due to its short range and directional interactions. In this work, we combined a cluster distribution theory with generalized Flory and Stockmayer percolation theory to investigate the interplay between phase behavior and percolation for a binary patchy colloid system. The binary patchy colloid system consists of solute molecules with spherically symmetric bonding sites and solvents with two singly bondable sites. Wertheim's first order thermodynamic perturbation theory (TPT1) has been widely applied to the patchy colloids system and it has been combined with percolation theory to study the percolation threshold. However, due to assumptions behind TPT1, it will lose accuracy for a system in which particles have multiple association sites or multiply bondable sites. A recently proposed cluster distribution theory accurately models association at sites that can form multiple bonds. In this work, we investigate the comparison among cluster distribution theory, TPT1, and Monte Carlo simulation for the bonding states of this binary system in which cluster distribution theory shows excellent agreement with Monte Carlo simulation, while TPT1 has a large deviation with the simulation. Cluster distribution theory was further combined with the Flory and Stockmayer percolation theory to investigate the interplay between phase behavior and percolation threshold. We found that the reduced density and the relative bonding strength of solvent-solvent association and solute-solvent association are key factors for the phase behavior and percolation. Percolation can form at low density and low temperature in the vapor phase of this binary system, where the star-like molecules with 12 long branches formed.

Binary Self-Assembly of Nanocolloidal Arrays using Concurrent and Sequential Spin Coating Techniques.

This paper reports the binary colloid assembly of nanospheres using spin coating techniques. Polystyrene spheres with sizes of 900 and 100 nm were assembled on top of silicon substrates utilizing a spin coater. Two different spin coating processes, namely concurrent and sequential coatings, were employed. For the concurrent spin coating, 900 and 100 nm colloidal nanospheres of latex were first mixed and then simultaneously spin coated onto the silicon substrate. On the other hand, the sequential coating process first created a monolayer of a 900 nm nanosphere array on the silicon substrate, followed by the spin coating of another layer of a 100 nm colloidal array on top of the 900 nm array. The influence of the processing parameters, including the type of surfactant, spin speed, and spin time, on the self-assembly of the binary colloidal array were explored. The empirical outcomes show that by employing the optimal processing conditions, binary colloidal arrays can be achieved by both the concurrent and sequential spin coating processes.