Aluminosilicate Nanoparticles Research Articles

A Metal-Phenolic Network-Enabled Nanoadjuvant to Modulate Immune Responses.

The presence of hierarchical suppressive pathways in the immune system combined with poor delivery efficiencies of adjuvants and antigens to antigen-presenting cells are major challenges in developing advanced vaccines. The present study reports a nanoadjuvant constructed using aluminosilicate nanoparticles (as particle templates), incorporating cytosine-phosphate-guanosine (CpG) oligonucleotides and small-interfering RNA (siRNA) to counteract immune suppression in antigen-presenting cells. Furthermore, the application of a metal-phenolic network (MPN) coating, which can endow the nanoparticles with protective and bioadhesive properties, is assessed with regard to the stability and immune function of the resulting nanoadjuvant in vitro and in vivo. Combining the adjuvanticity of aluminum and CpG with RNA interference and MPN coating results in a nanoadjuvant that exhibits greater accumulation in lymph nodes and elicits improved maturation of dendritic cells in comparison to a formulation without siRNA or MPN, and with no observable organ toxicity. The incorporation of a model antigen, ovalbumin, within the MPN coating demonstrates the capacity of MPNs to load functional biomolecules as well as the ability of the nanoadjuvant to trigger enhanced antigen-specific responses. The present template-assisted fabrication strategy for engineering nanoadjuvants holds promise in the design of delivery systems for disease prevention, as well as therapeutics.

Multivariate regression analysis of factors regulating the formation of synthetic aluminosilicate nanoparticles.

Interest is growing in nanoparticles made of earth abundant materials, like alumino(silicate) minerals. Their applications are expanding to include catalysis, carbon sequestration reactions, and medical applications. It remains unclear, however, what factors control their formation and abundance during laboratory synthesis or on a larger industrial scale. This work investigates the complex system of physicochemical conditions that influence the formation of nanosized alumino(silicate) minerals. Samples were synthesized and analyzed by powder X-ray diffraction, in situ and ex situ small angle X-ray scattering, and transmission electron microscopy. Regression analyses combined with linear combination fitting of powder diffraction patterns was used to model the influence of different synthesis conditions including concentration, hydrolysis ratio and rate, and Al : Si elemental ratio on the particle size of the initial precipitate and on the phase abundances of the final products. These models show that hydrolysis ratio has the strongest control on the overall phase composition, while the starting reagent concentration also plays a vital role. For imogolite nanotubes, we determine that increasing concentration, and relatively high or low hydrolysis limit nanotube production. A strong relationship is also observed between the distribution of nanostructured phases and the size of precursor particles. The confidences were >99% for all linear regression models and explained up to 85% of the data variance in the case of imogolite. Additionally, the models consistently predict resulting data from other experimental studies. These results demonstrate the use of an approach to understand complex chemical systems with competing influences and provide insight into the formation of several nanosized alumino(silicate) phases.

Hemolytic Activity and Cytotoxicity of Synthetic Nanoclays with Montmorillonite Structure for Medical Applications.

The factors influencing the appearance of toxicity in samples of synthetic montmorillonite with a systematically changing chemical composition Nax(Al, Mg)2-3Si4O10(OH)2 nH2O, which are potentially important for their use in medicine as drug carriers, targeted drug delivery systems, entero- and hemosorbents have been studied. Samples synthesized under hydrothermal conditions had the morphology of nanolayers self-organized into the nanosponge structures. The effect of the aluminum content, particle sizes, porosity, and ζ-potential of the samples on their toxicity was studied. The cytotoxic effect of the samples on eukaryotic cells Ea. hy 926 was determined using the MTT assay. The hemolytic activity of the samples in the wide concentration range in relation to human erythrocytes was also estimated. It has been established that the toxicity of aluminosilicate nanoparticles can be significantly reduced by correctly selecting their synthesis conditions and chemical composition, which opens up the opportunities for their use in medicine.

Antibody Functionalization of Ultrasmall Fluorescent Core–Shell Aluminosilicate Nanoparticle Probes for Advanced Intracellular Labeling and Optical Super Resolution Microscopy

Fluorescent labeling of cellular substructures is commonly performed using antibody–organic dye conjugates. Organic dyes do not exhibit ideal optical properties in terms of brightness and photostability, however, in particular when it comes to advanced optical super-resolution microscopy (SRM) applications. Here, we demonstrate the efficient conjugation of widely available secondary antibodies and cationic species to ultrasmall (sub-10 nm) fluorescent silica core─poly(ethylene glycol) shell (core–shell) aluminosilicate nanoparticles (aC′ dots) encapsulating different color dyes for specific targeting and high-quality fluorescence imaging of structures of the cytoskeleton (tubulin and actin) and nucleus, respectively. We show that the different color aC′ dots provide enhanced brightness and photostability relative to their parent dyes. As recently discovered, we further demonstrate that they exhibit photo-induced blinking with low ON–OFF duty cycles enabling optical SRM, for example, in the form of stochastic optical reconstruction microscopy (STORM), without the need for complex imaging setups or cocktails. After carefully optimizing Ab–aC′ dot conjugation as well as cell structure labeling protocols in fixed and permeabilized HeLa and MDA-MB-231 cells, we demonstrate three-color STORM and exemplify improved resolution compared to standard antibody–dye conjugates. This work paves the way to next-generation multifunctional optical probes based on ultrasmall silica nanoparticle platforms for advanced applications in bioimaging, nanomedicine, and beyond.

Control of carbonation mechanism in Portland cement paste using synthetic carbon-capture aluminosilicates

In this research, synthetic aluminosilicate nanoparticles in the form of engineered synthetic aluminosilicates (ESA) were added to a cement paste to create a more controlled environment for carbonation and subsequent hydration reactions. To date, early-age CO2 curing of Portland cement pastes has been shown to reduce the later-age performance due to the decalcification of hydration products and starvation of water by early-age carbonation. However, in this study, it was demonstrated that it is possible to control the carbonation and subsequent hydration reactions through the addition of ESA. Two types of synthetic aluminosilicates were synthesised using organosilanes, tetraethoxysilane (TEOS), and functionalised organosilane, 3-aminopropyltriethoxysilane (APTES). The two aluminosilicates behaved slightly differently, confirming the possibility of altering the carbonation and subsequent hydration reactions. The research demonstrates that tailored nanoparticles enhance carbonate formation by preventing decalcification of the hydration product. The ESA took part in pozzolanic reactions which resulted in no starvation of water on carbonation and led to improved performance at a later age when compared to the samples without ESA. Furthermore, decalcification of portlandite was not observed on the addition of ESA. The carbonation reaction mechanisms on the addition of these ESAs were postulated, and the possibility of increase in carbon uptake without affecting the mechanical performance at later ages were shown.

Physicochemical Characteristics and Growth Mechanisms of the Aluminosilicate Nanoparticles for Synthesis of Clinoptilolite

AbstractIn order to understand the growth behaviors of the aluminosilicate species in the initial hydrothermal process and thereafter synthesis of clinoptilolites with high purity, the physicochemical characteristics of the aluminosilicate nanoparticles were elucidated by small angle X‐ray scattering (SAXS) and X‐ray diffraction (XRD) patterns, scanning electron microscopy (SEM) images, Ultra‐Violet Raman (UV‐Raman) and Fourier transform infrared (FT‐IR) spectra. The results demonstrated that the aluminosilicate nanoparticles presented the first decreased surface fractal (Ds) values and then an increased Ds values in the initial reaction time of before 120 h. After that, the fractal transformations from Ds to mass fractal (Dm) occurred with the extensions of reaction time (120–144 h), but the decreased Dm values appeared after 144 h. Therefore, their growth mechanisms from uniform dispersions to aggregation, and even assembly were proposed.

Particles Morphology Impact on Cytotoxicity, Hemolytic Activity and Sorption Properties of Porous Aluminosilicates of Kaolinite Group

A comparative study of the properties of aluminosilicates of the kaolinite (Al2Si2O5(OH)4∙nH2O) group with different particles morphology has been carried out. Under conditions of directed hydrothermal synthesis, kaolinite nanoparticles with spherical, sponge, and platy morphologies were obtained. Raw nanotubular halloysite was used as particles with tubular morphology. The samples were studied by X-ray diffraction, SEM, solid-state NMR, low-temperature nitrogen adsorption, and the dependence of the zeta potential of the samples on the pH of the medium was defined. The sorption capacity with respect to cationic dye methylene blue in aqueous solutions was studied. It was found that sorption capacity depends on particles morphology and decreases in the series spheres-sponges-tubes-plates. The Langmuir, Freundlich, and Temkin models describe experimental methylene blue adsorption isotherms on aluminosilicates of the kaolinite subgroup with different particles morphology. To process the kinetic data, pseudo-first order and pseudo-second order were used. For the first time, studies of the dependence of hemolytic activity and cytotoxicity of aluminosilicate nanoparticles on their morphology were carried out. It was found that aluminosilicate nanosponges and spherical particles are not toxic to human erythrocytes and do not cause their destruction at sample concentrations from 0.1 to 1 mg/g. Based on the results of the MTT test, the concentration value that causes 50% inhibition of cell population growth (IC50, mg/mL) was calculated. For nanotubes, this value turned out to be the smallest—0.33 mg/mL. For samples with platy, spherical and nanosponge morphology, the IC50 values were 1.55, 2.68, and 4.69 mg/mL, respectively.

Modification of Thin Film Composite PVA/PAN Membranes for Pervaporation Using Aluminosilicate Nanoparticles.

The effect of the modification of the polyvinyl alcohol (PVA) selective layer of thin film composite (TFC) membranes by aluminosilicate (Al2O3·SiO2) nanoparticles on the structure and pervaporation performance was studied. For the first time, PVA-Al2O3·SiO2/polyacrylonitrile (PAN) thin film nanocomposite (TFN) membranes for pervaporation separation of ethanol/water mixture were developed via the formation of the selective layer in dynamic mode. Selective layers of PVA/PAN and PVA-Al2O3·SiO2/PAN membranes were formed via filtration of PVA aqueous solutions or PVA-Al2O3·SiO2 aqueous dispersions through the ultrafiltration PAN membrane for 10 min at 0.3 MPa in dead-end mode. Average particle size and zeta potential of aluminosilicate nanoparticles in PVA aqueous solution were analyzed using the dynamic light scattering technique. Structure and surface properties of membranes were studied using scanning electron microscopy (SEM), atomic force microscopy (AFM) and water contact angle measurements. Membrane performance was investigated in pervaporation dehydration of ethanol/water mixtures in the broad concentration range. It was found that flux of TFN membranes decreased with addition of Al2O3·SiO2 nanoparticles into the selective layer due to the increase in selective layer thickness. However, ethanol/water separation factor of TFN membranes was found to be significantly higher compared to the reference TFC membrane in the whole range of studied ethanol/water feed mixtures with different concentrations, which is attributed to the increase in membrane hydrophilicity. It was found that developed PVA-Al2O3·SiO2/PAN TFN membranes were more stable in the dehydration of ethanol in the whole range of investigated concentrations as well as at different temperatures of the feed mixtures (25 °C, 35 °C, 50 °C) compared to the reference membrane which is due to the additional cross-linking of the selective layer by formation hydrogen and donor-acceptor bonds between aluminosilicate nanoparticles and PVA macromolecules.

Smart polymeric nanocomposite based on protonated aluminosilicate, curcumin, and chitosan for mesalamine drug delivery as an anti-inflammatory nanocarrier

Due to the importance of the colon-specific disease, its treatment with reduced side effects has become fascinating over the last decades. The aim of this study was the synthesis of the nanocomposite based on the protonated aluminum-modified mesoporous silica nanoparticles (H/Al-MSN) and curcumin possesses mesalamine to develop its efficacy and eliminating side effects for enhancing permeability in intestinal tissues. Here, different amounts of mesalamine were loaded and studied under accurate analysis in order to evaluate release quality. The aluminosilicate nanoparticles are encapsulated by the combination of curcumin as an herbal product and also chitosan as a natural biopolymer with the advantages of non-toxicity, biocompatibility, biodegradability, and non-allergenic. The release of mesalamine from the nanocomposite was investigated in different pH included acidic, neutral, and alkaline media. The results showed that the release of mesalamine is dependent on acidity. A colonic drug delivery system was designed based on the release time and pH sensitivity. The drug release was studied at pH 5.5, 7, and 8 a different region of the gastrointestinal tract was simulated. The results showed that the trend of mesalamine release is higher at pH 8 with high efficacy performance of more than 90% at room temperature for about 90 h.

Mesoporous sodium four-coordinate aluminosilicate nanoparticles modulate dendritic cell pyroptosis and activate innate and adaptive immunity.

Pyroptosis is a programmed cell death widely studied in cancer cells for tumour inhibition, but rarely in dendritic cell (DC) activation for vaccine development. Here, we report the synthesis of sodium stabilized mesoporous aluminosilicate nanoparticles as DC pyroptosis modulators and antigen carriers. By surface modification of sodium-stabilized four-coordinate aluminium species on dendritic mesoporous silica nanoparticles, the resultant Na-IVAl-DMSN significantly activated DC through caspase-1 dependent pyroptosis via pH responsive intracellular ion exchange. The released proinflammatory cellular contents further mediated DC hyperactivation with prolonged cytokine release. In vivo studies showed that Na-IVAl-DMSN induced enhanced cellular immunity mediated by natural killer (NK) cells, cytotoxic T cells, and memory T cells as well as humoral immune response. Our results provide a new principle for the design of next-generation nanoadjuvants for vaccine applications.

Condensation and growth of amorphous aluminosilicate nanoparticles via an aggregation process.

The precipitation of zeolite nanoparticles involves the initial formation of metastable precursors, such as amorphous entities, that crystallize through non-classical pathways. Here, using reactive force field-based simulations, we reveal how aluminosilicate oligomers grow concomitantly to the decondensation of silicate entities during the initial step of the reaction. Aluminate clusters first form in the solution, thus violating the Loewenstein rule in the first instant of the reaction, which is then followed by their connection with silicate oligomers at the terminal silanol groups before reorganization to finally diffuse within the silicate oligomers to form stable amorphous aluminosilicate nanoparticles that do obey the Loewenstein rule. Our results clearly indicate that aluminate does not serve as the nucleation center for the growth of aluminosilicates in a nucleation-like process but rather proceeds via an aggregation process. The coexistence of aluminosilicate oligomers and small silicate entities induces a phase separation that promotes the precipitation of zeolites with aging.

Aluminosilicate nanoparticles decorated by copper hexacyanoferrate as a good electrocatalyst for non-enzymatic hydrogen peroxide sensing

In this work, porous amorphous aluminosilicates nanoparticles (PAS NPs) have been synthesized by the sol-gel method. The crystals particle sizes of PAS NPs were about 90 nm by SEM. Carbon paste modified PAS NPs/Cu (CPE/PAS NPs/Cu) was placed into a potassium hexacyanoferrate solution by continuous cycling of the potential for deposition of copper hexacyanoferrate (CuHCF) at the surface of CPE/PAS NPs/Cu. The cyclic voltammograms of CPE/PAS NPs/CuHCF show two pairs (Fe(CN)6 3−/Fe(CN)6 4− and Cu2+/Cu+) of redox couples due to the system. The total surface coverage of immobilized CuHCF was calculated at about 1.65 × 10−7 mol cm−2. Finally, this modified electrode responded to the different concentrations of hydrogen peroxide. The linear range and limit of detection (LOD) were 0.8–1.8 × 102 μmol L−1 and 0.65 μmol L−1, respectively. The fabrication of this electrode is easy and it is simple and low-cost. The stability, reproducibility, and repeatability of this modified electrode are acceptable.

Aluminosilicate Nanosponges: Synthesis, Properties, and Application Prospects.

A simple one-step method is presented for fabricating inorganic nanosponges with a kaolinite [Al2Si2O5(OH)4] structure. The nanosponges were synthesized by the hydrothermal treatment of aluminosilicate gels in an acidic medium (pH = 2.6) at 220 °C without using organic cross-linking agents, such as cyclodextrin or polymers. The formation of the nanosponge morphology was confirmed by scanning electron microscopy, and the assignment of the synthesized aluminosilicates to the kaolinite group was confirmed by X-ray diffraction and infrared spectroscopy. The effect of the synthesis conditions, in particular, the nature (HCl, HF, NaOH, and H2O) and pH of the reaction medium (2.6, 7, and 12), as well as the duration of the synthesis (3, 6, and 12 days), on the morphology of aluminosilicates of the kaolinite group was studied. The sorption capacity of aluminosilicate nanosponges with respect to cationic (e.g., methylene blue) and anionic (e.g., azorubine) dyes in aqueous solutions was studied. The pH sensitivity of the surface ζ potential of the synthesized nanosponges was demonstrated. The dependence of the hemolytic activity (the ability to destroy erythrocytes) of aluminosilicate nanoparticles on the particle morphology (platy, spherical, and nanosponge) has been identified for the first time. Aluminosilicate nanosponges were not found to exhibit hemolytic activity. The prospects of using aluminosilicate nanosponges to prepare innovative functional materials for ecology and medicine applications, in particular, as matrices for drug delivery systems, were identified.

A facile method of generating aluminosilicate nanoparticles: Complete fragmentation of kaolinite nanoscrolls via manual grinding

Aluminosilicate nanoparticles were prepared by the complete breakdown of the tube walls of kaolinite nanoscrolls by manual grinding. Transmission electron microscopy observation of the product showed a lack of the original hollow cylindrical morphology together with the formation of nanoparticles Hysteresis over the relative pressure range of 0.50–0.95 was present in the nitrogen adsorption/desorption isotherm of kaolinite nanoscroll but not in that of ground product. These results indicate the successful formation of kaolinite nanoparticles using a simple grinding method.

Addressing Particle Compositional Heterogeneities in Super-Resolution-Enhanced Live-Cell Ratiometric pH Sensing with Ultrasmall Fluorescent Core-Shell Aluminosilicate Nanoparticles.

The interrogation of metabolic parameters like pH in live-cell experiments using optical super-resolution microscopy (SRM) remains challenging. This is due to a paucity of appropriate metabolic probes enabling live-cell SRM-based sensing. Here we introduce ultrasmall fluorescent core-shell aluminosilicate nanoparticle sensors (FAM-ATTO647N aC' dots) that covalently encapsulate a reference dye (ATTO647N) in the core and a pH-sensing moiety (FAM) in the shell. Only the reference dye exhibits optical blinking enabling live-cell stochastic optical reconstruction microscopy (STORM). Using data from cells incubated for 60 minutes with FAM-ATTO647N aC' dots, pixelated information from total internal reflection fluorescence (TIRF) microscopy-based ratiometric sensing can be combined with that from STORM-based localizations via the blinking reference dye in order to enhance the resolution of ratiometric pH sensor maps beyond the optical diffraction limit. A nearest-neighbor interpolation methodology is developed to quantitatively address particle compositional heterogeneity as determined by separate single-particle fluorescence imaging methods. When combined with STORM-based estimates of the number of particles per vesicle, vesicle size, and vesicular motion as a whole, this analysis provides detailed live-cell spatial and functional information, paving the way to a comprehensive mapping and understanding of the spatiotemporal evolution of nanoparticle processing by cells important, e.g. for applications in nanomedicine.

Ultrasmall, Bright, and Photostable Fluorescent Core-Shell Aluminosilicate Nanoparticles for Live-Cell Optical Super-Resolution Microscopy.

Stochastic optical reconstruction microscopy (STORM) is an optical super-resolution microscopy (SRM) technique that traditionally requires toxic and non-physiological imaging buffers and setups that are not conducive to live-cell studies. It is observed that ultrasmall (<10nm) fluorescent core-shell aluminosilicate nanoparticles (aC' dots) covalently encapsulating organic fluorophores enable STORM with a single excitation source and in a regular (non-toxic) imaging buffer. It is shown that fourfold coordinated aluminum is responsible for dye blinking, likely via photoinduced redox processes. It is demonstrated that this phenomenon is observed across different dye families leading to probes brighter and more photostable than the parent free dyes. Functionalization of aC' dots with antibodies allows targeted fixed cell STORM imaging. Finally, aC' dots enable live-cell STORM imaging providing quantitative measures of the size of intracellular vesicles and the number of particles per vesicle. The results suggest the emergence of a powerful ultrasmall, bright, and photostable optical SRM particle platform with characteristics relevant to clinical translation for the quantitative assessment of cellular structures and processes from live-cell imaging.

Synthesis of Spiro1,4-Dihydropyridines: A Review.

The preparation of medicinally promising spiro1,4-dihydropyridines accompanied by their applications in biological and pharmaceutical activities is presented. Spiro1,4-dihydropyridines were synthesized using numerous reported methods including bronested acids such as p-TSA, AcOH, nano-ranged calix[4]arene tetracarboxylic acid, sulfamic acid, PEG-OSO3H, tetramethylguanidinium triflate; lewis acids including Zn(OTf)2, FeCl3, copper, alum, aluminosilicate nanoparticles, MnFe2O4 nanoparticles, manganese ferrite nanoparticles, BF3OEt2; under alkaline conditions such as Et3N and piperidine; ionic liquids such as [KAl(SO4)2·12H2O] and [Bmim]PF6, [MIM(CH2)4SO3H][HSO4]; and other miscellaneous procedures, for example, microwave-assisted catalyst and solvent-free conditions, using iodine, PEG-400, and NaCl.

Transformation of Discrete Amorphous Aluminosilicate Nanoparticles into Nanosized Zeolites

AbstractThe effect of amorphous aluminosilicate precursor nanoparticles on the formation of nanosized zeolites with faujasite (FAU) and sodalite (SOD) type frameworks is illustrated using a new synthetic strategy to prepare nanosized zeolites with tailored particle size distribution, morphology, and structure. This two‐step synthesis procedure includes the formation of colloidal suspensions followed by separation of the amorphous precursor nanoparticles, and their subsequent transformation into nanosized crystals by treatment with alkali suspensions (NaOH) solutions only. The selective transformation of the amorphous nanoparticles into FAU and SOD nanosized crystals is studied at atomistic and microscopic levels using 29Si and 23Na nuclear magnetic resonanse (NMR) spectroscopy, X‐ray powder diffraction, and N2 physisorption, respectively. The presence of sodalite cages occluding highly mobile sodium in the amorphous nanoparticles is confirmed by 23Na‐1H D‐HMQC NMR spectroscopy. The subsequent treatment of these amorphous precursor particles with aqueous sodium hydroxide illustrates that the cations are not only charge compensators but also inorganic templates stabilizing sodalite cages during the long‐range ordering in the amorphous particles.

Cr4+ activated NIR-NIR multi-mode luminescent nanothermometer for double biological windows

Remote temperature sensing in biological media is used to monitor intracellular evolutionary process reliably, and is potentially applied in the field of diagnostics and therapeutics. Ideally, such nanothermometers should be functional in biological optical transparency windows across a wide range of broad absorption and emission bands, strong luminescence and larger Stokes shift. Here, this is achieved via using NIR-to-NIR transition metal (Cr4+)-doped aluminosilicate nanoparticles as multiparametric thermal sensing probes. They can be excited in first biological window and emitted in second biological window, allowing for large optical penetration into tissues while maintaining high-spatial resolution. We also demonstrate that the phenomena of temperature-induced population redistribution and temperature-induced spectral red-shift (maximum thermal sensitivity is 0.61% °C−1, superior to the most of the current materials), essentially allow for a multi-mode thermal sensing within a single probe towards to a very different optical response. We believe that these findings can be expanded a wide range of promising applications using transition metal-activated luminescent nanoparticles as nanothermometers in deep tissue temperature measurements of biological and biochemical.

Microstructure and Antimicrobial Properties of Bioactive Cobalt Co-Doped Copper Aluminosilicate Nanocrystallines

Eco-friendly copper aluminosilicate nanoparticles doped with cobalt nanoparticles were prepared via the sol-gel route. The samples were calcined at 800 °C to induce high crystallization, which would potentially enhance their structural, spectroscopic and antimicrobial properties. Structural and spectroscopic characterization were measured using X-ray diffraction, Field emission-scanning electron microscopy, Fourier Transformed Infrared, UV-Vis-absorbance and UV/Vis diffuse reflectance spectra. The product revealed the formation of a crystalline cubic phase of (CAS) and orthorhombic (β-Co2SiO4) phase. The antimicrobial susceptibility testing of nanocrystalline CAS, 5Co-CAS and 9Co-CAS as magnetic nanocomposites was evaluated using agar diffusion and broth dilution methods against Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa, Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, Candida albicans, and Aspergillus niger. The toxicity assays for each antiseptic were also conducted. The incorporation of cobalt ions in the silicate base material was observed to be highly cross-linked during the formation process. UV-Vis-absorbance for the samples gave a red shift and noticeable increases in the band gap with the values 1.42, 1.43, 1.52 and 1.50 eV, respectively. The results showed that 9Co-CAS was the most potent antiseptic followed by 5Co-CAS and CAS.