Size Of Microbeads Research Articles

Precisely controlled electrostatically sprayed sodium alginate/carboxymethyl chitosan hydrogel microbeads as super-adsorbent for adsorption of cationic dye.

In this pioneering study, electrostatic spraying (ES) technology with high voltages is proposed to reduce the size of hydrogel microbeads further, aiming to enhance the adsorption rate of cationic methylene blue (MB) dye. The increased voltages, ranging from 0.0 to 13.0 kV, further decreased the size of electrostatically sprayed hydrogel microbeads crosslinked by hydrogen bonds between sodium alginate (SA) and carboxymethyl chitosan (CMCS) in hydrochloric acid. The size of SA/CMCS hydrogel microbeads was successfully reduced from 2000 ± 121 μm (SC-2000) to 400 ± 15 μm (SC-400). Notably, SC-400 exhibits the highest maximum adsorption capacity (qm) and rate constant (k2) at 840.3 mg/g and 0.0598 g/mg/min, respectively, at pH 9.0 and a temperature of 25 °C in the absence of ionic compounds, which is three times higher than that of SC-2000, due to their high specific surface area and pore volume. Through a series of adsorption studies and characterization analyses, SA/CMCS hydrogel microbeads displayed heterogeneous adsorption behaviors towards MB dye through electrostatic interactions between the deprotonated carboxylic groups and cationic MB molecules, where MB adsorption efficiency could be significantly influenced by pH and ionic strength. These findings suggest that ES technology is effective in synthesizing smaller SA/CMCS hydrogel microbeads with enhanced MB removal rates and stable adsorption capacities and their applications could be further explored for removing other organic dyes and toxic metals in subsequent research studies.

Microbeads in exfoliating products: occurrence, abundance, and potential for water contamination in Ho Chi Minh City, Vietnam

Microbeads in exfoliating products are a significant source of microplastics entering aquatic ecosystems. This study characterized microbeads in popular facial scrub and body scrub products from Ho Chi Minh City, Vietnam, to quantify abundances and estimate emissions. A selection of facial scrub and body scrub cleansers were collected from local markets and analyzed to quantify microbead properties including the size, color, mass, and abundance of microbeads in the exfoliating cleansers. Results revealed a wide range of microbead sizes (66–1012 μm) and different shapes and colors within and between products. Most contained heterogenous particles of white, green, blue, red, brown, and black spherical microbeads. The range of microbead abundance was 236–942 particles per gram of product. Annual microbead emissions from the use of these products in Ho Chi Minh City were estimated based on population and usage data. The total annual emission of microbeads from facial and body scrubs in Ho Chi Minh City amounted to 1.3 billion microbeads. On a per capita basis, this equaled 880 microbeads per person annually discharged into the local water environment. According to the study, a preliminary calculation indicated that approximately 2640 microbeads were released per year per female student in Ho Chi Minh City. By providing an initial ssessment of microbead pollution arising specifically from personal care items in Vietnam, this study raises awareness of microplastics introduction into Asian coastal zones via cosmetic products. The baseline data establishes a foundation for further investigations. This represents an important step in quantifying and addressing an emerging microplastic source in the region.

Fabrication of porous poly(L-lactide-co-ε-caprolactone) micropowder for microbubble effect and ultrasound-mediated drug delivery.

Biodegradable elastic poly(L-lactide-co-ε-caprolactone) (PLCL) copolymer (50:50, lactide:caprolactone molar ratio) was synthesized and porous PLCL micropowders was fabricated by a simple method involving rapid cooling of 0.1, 0.5, and 1% (wt/vol) PLCL/dioxane spray into liquid nitrogen. The physicochemical properties of the porous PLCL micropowders were examined by measuring their pore size, pore morphology, and microbead size using a scanning electron microscopy (SEM) and dye and temozolomide (TMZ)-release testing under ultrasound. Human U-87MG, glioblastoma (GBM) cell culture tests were performed to evaluate cell cytotoxicity by released drug from PLCL micropowders. In this study, the porous PLCL micropowders prepared from 1 wt%/vol% PLCL solutions showed a highly porous structure, satisfactory mechanical properties, and optimal drug release efficiency compared with those produced from 0.1 or 0.5 wt%/vol% solutions. The results of the accumulated release test with the results of the absorbance of the dye initially applied, it was confirmed that more than 80% of the added dye was trapped inside the micropowder, and clearly GBM cytotoxicity effect could be observed by the released TMZ. The drug release system using micropowders and ultrasound can be applied as a drug supply system for various diseases such as brain tumors with low drug permeability.

Clean, but not green: Emission assessment, forecast modelling and policy solutions for plastic microbeads from personal care products in India

Intentionally added plastic microbeads in personal care products (PCP) are an underestimated source of microplastics. These microbeads are added as fillers, to increase product volume or aesthetics and allegedly have the purpose of cleansing and exfoliation. To assess and forecast microbead emissions in India, this study analysed 45 items from four different categories of personal care products: face wash, face scrub, shower gel and body scrub available in the Indian market and determined microbead abundance, size, colour, shape and polymer composition. Also, an emission estimation and time-series-based forecast for 2030 was done using ARIMA (0,2,0) for individual categories and overall. The results indicate that 45.00 % of the products contained irregular or smooth microplastics, with Polyethylene being the dominant polymer, followed by Polypropylene, Polystyrene, Polyurethane and Polycaprolactone. A significant number of products (23.33%) contained cellulose microbeads, with ambiguity regarding their biodegradability. The identified microbeads were mainly irregular in shape and granular in texture, especially scrubs. White/transparent colour dominated the identified microbeads, followed by blue, pink, yellow, red and green. Approximately 1.34% of the total product contained plastic microbeads, with 5.04% and 0.04% being the highest and lowest percentages quantified. The average size of microbeads was found to be 640.74 μm, 452.45 μm, 556.66 μm and 606.30 μm in different categories. The overall annual emission estimation was 3.51 × 1019(highest), 2.14 × 1018(lowest) and 1.37 × 1019(average) in 2021 and forecasted to be 4.12 × 1019(highest), 2.52 × 1018(lowest) and 1.61 × 1019(average)in 2030. This exorbitantly high value is due to India's significant population, globalisation, inefficient wastewater efficiency, growing economy and disposable income. A lack of policies and adequate regulations further add to this. This study emphasises and recommends the development of stringent policies and other well-tailored mitigation measures for intentionally added microbeads in PCP in India. The study recommends some policy measures to curb this threat.

Fabrication, characterization and release behavior of α-tocopherol acetate-loaded pH-responsive polyhydroxybutyrate/cellulose acetate phthalate microbeads

Microbeads are used in personal care and cosmetic products (PCCPs) but are produced from nondegradable materials. Biodegradable polyhydroxybutyrate (PHB) has been recognized as a promising alternative material for use in PCCPs; however, utilizing PHB to encapsulate PCCPs is challenging because PCCPs need to be protected from the environment but their release needs to be permitted under specific physiological conditions. The aim of this work was to develop and evaluate pH-responsive cellulose acetate phthalate (CAP) to formulate lipophilic α-tocopherol acetate (α-TA)-loaded pH-responsive PHB/CAP microbeads. The influences of the PHB/CAP ratio and initial α-TA loading on the microbead size, surface morphology, encapsulation efficiency (%EE), loading capacity (%LC), and α-TA release profile were studied. The microbeads exhibited a spherical shape with a size of 328.7 ± 2.9 μm. The EE and LC were 86.7 ± 2.6 % and 13.5 ± 0.4 %, respectively. The release profile exhibited pH-responsive characteristics. These α-TA-loaded pH-responsive microbeads were stable with >50 % of the α-TA remaining after 90 days at 4, 25 and 45 °C in the dark. The results from the cytotoxicity assay with PSVK1 cells demonstrated that the microbeads were nontoxic. Hence, our developed formulation has the potential to be used to encapsulate oil-based drugs to formulate lipophilic substance-loaded pH-responsive microbeads.

One-step biofabrication of liquid core-GelMa shell microbeads for in situ hollow cell ball self-assembly.

There are many instances of hollow-structure morphogenesis in the development of tissues. Thus, the fabrication of hollow structures in a simple, high-throughput and homogeneous manner with proper natural biomaterial combination is valuable for developmental studies and tissue engineering, while it is a significant challenge in biofabrication field. We present a novel method for the fabrication of a hollow cell module using a coaxial co-flow capillary microfluidic device. Sacrificial gelatin laden with cells in the inner layer and GelMa in the outer layer are used via a coaxial co-flow capillary microfluidic device to produce homogenous micro-beads. The overall and core sizes of core-shell microbeads were well controlled. When using human vein vascular endothelial cells to demonstrate how cells line the inner surface of core-shell beads, as the core liquifies, a hollow cell ball with asymmetric features is fabricated. After release from the GelMa shell, individual cell balls are obtained and deformed cell balls can self-recover. This platform paves way for complex hollow tissue modeling in vitro, and further modulation of matrix stiffness, curvature and biochemical composition to mimic in vivo microenvironments.

Microbeads in personal care products sold in Pakistan: extraction, quantification, characterization, and buoyancy analysis.

Microbeads used in personal care products (PCPs) as an exfoliating agent or as a sorbent phase for delivering active ingredients are the most common sources of microplastics. The release of these plastic microbeads into aquatic environments has raised significant concerns due to their direct availability for ingestion by organisms upon entering the recipientwaters. In this study, twelve personal care products (PCPs; 5 face washes and 7 scrubs) were analyzed for microbead content, size, polymer type, and buoyant behavior. Among the face washes, the highest microbead content (i.e., 11 ± 1.2 mg/g) was found in Neutrogena (NS), while the lowest was found in Nivea (NI) with 0.33 ± 0 mg/g. In case of scrubs, Cool and Cool (CL) contained a higher concentration of microbeads (i.e., 57.08±14.15 mg/g) and a lower concentration was found in Yong Chin (YC) (i.e., 10.5±1.5 mg/g). The sizes of microbeads ranged from 3.14 ± 0 to 747 ± 313 μm, and most of the isolated microbeads showed negative buoyant behavior in both freshwater and seawater. The FTIR spectra showed that the microbeads were mainly composed of ethyl-vinyl acetate (66.66%), high-density polyethylene (16.66%), polyethylene terephthalate (8.3%), and nitrile (8.3%). The presence of plastic microbeads in PCPs highlights the need to regulate their use as an exfoliating agent and to raise public awareness to prevent the discharge of these persistent and potentially harmful elements into the environment.

SAN-including PVDF membranes with improved permeability for hypersaline water desalination using DCMD process

Styrene-acrylonitrile (SAN) was added to polyvinylidene fluoride (PVDF)/N-methyl-2 pyrrolidone (NMP) system to fabricate SAN-modified PVDF membranes using non-solvent induced phase separation (NIPS). By increasing the SAN concentration in casting solution, number of microbeads started to grow. However, by further increasing the amount of SAN, size of microbeads was also increased. Surface hydrophobicity of neat ethanol-induced composite membrane was increased from 139.2 ± 1 to 148.7° ±1, since SAN polymer incorporation bestowed another texture to whole structure. Different salty feed solutions, i.e., 35 and 105 g/L, were used as feed by direct contact membrane distillation (DCMD) process. Permeate flux and salt rejection were high enough with stable permeation using 35 g/L feed solution. Neat and well-modified PVDF/SAN membranes were then applied for hypersaline DCMD test. During 38 h desalination test using SAN-modified membrane, permeate flux and salt rejection of 29.74 ± 1 kg/m2 h and >99.9 % were achieved, respectively. Also, due to multi-textured structure, permeate flux enhancement and better scaling resistance were observed using SAN/PVDF membrane. A sufficient way was proposed to improve desalination performance using a straightforward fabrication process.

An impedance flow cytometry with integrated dual microneedle for electrical properties characterization of single cell

Electrical characteristics of living cells have been proven to reveal important details about their internal structure, charge distribution and composition changes in the cell membrane, as well as the extracellular context. An impedance flow cytometry is a common approach to determine the electrical properties of a cell, having the advantage of label-free and high throughput. However, the current techniques are complex and costly for the fabrication process. For that reason, we introduce an integrated dual microneedle-microchannel for single-cell detection and electrical properties extraction. The dual microneedles utilized a commercially available tungsten needle coated with parylene. When a single cell flows through the parallel-facing electrode configuration of the dual microneedle, the electrical impedance at multiple frequencies is measured. The impedance measurement demonstrated the differential of normal red blood cells (RBCs) with three different sizes of microbeads at low and high frequencies, 100 kHz and 2 MHz, respectively. An electrical equivalent circuit model (ECM) was used to determine the unique membrane capacitance of individual cells. The proposed technique demonstrated that the specific membrane capacitance of an RBC is 9.42 mF/m−2, with the regression coefficients, at 0.9895. As a result, this device may potentially be used in developing countries for low-cost single-cell screening and detection.

Engineering Modular, Oxygen-Generating Microbeads for the In Situ Mitigation of Cellular Hypoxia.

Insufficient oxygenation is a key obstacle in the design of clinically scalable tissue-engineered grafts. In this work, an oxygen-generating composite material, termed OxySite, is created through the encapsulation of calcium peroxide (CaO2 ) within polydimethylsiloxane and formulated into microbeads for ease in tissue integration. Key material parameters of reactant loading, porogen addition, microbead size, and an outer rate-limiting layer are modulated to characterize oxygen generation kinetics and their suitability for cellular applications. In silico models are developed to predict the local impact of different OxySite microbead formulations on oxygen availability within an idealized cellular implant. Promising OxySite microbead variants are subsequently coencapsulated with murine β-cells within macroencapsulation devices, resulting in improved cellular metabolic activity and function under hypoxic conditions when compared to controls. Additionally, the coinjection of optimized OxySite microbeads with murine pancreatic islets within a confined transplant site demonstrates ease of integration and improved primary cell function. These works highlight the broad translatability delivered by this new oxygen-generating biomaterial format, whereby the modularity of the material provides customization of the oxygen source to the specific needs of the cellular implant.

Formulation Development and Evaluation of Sustained Release Ranolazine Microbeads using Natural Polymer

The goal of this study was to develop sustained-release microbeads containing Ranolazine. The Ranolazine was selected on the basis of its short half-life i.e., 1.5 h and used in treatment of Angina pectoris. The fundamental goal of this research is to increase duration of drug release. Ranolazine was encapsulated with natural polymers such as Hygrophila auriculata seed mucilage by an ionotropic gelation technique. The formulation batches were optimized with a 32 factorial design and physicochemical characteristics were also evaluated. The particle size of microbeads, entrapment efficiency of drug, surface morphology, In-vitro release of drug was investigated.
 The in-vitro studies of optimized microbeads formulation batch (B2) containing 100:600 ratio of Hygrophila auriculata seed mucilage and sodium alginate exhibited as a sustained release of Ranolazine up to 12 h and. The mucoadhesion potential was found to be 97± 1% up 12 h. In our perspective, the current ER pellet formulation might be the most feasible alternative to traditional pain management formulas.
 All the trial’s batches were shown to be suitable in extended release of a short elimination half-life medication with enhanced bioavailability, implying that it is useful for oral drug delivery.
 Keywords: Design of experiment, Extrusion-spheronization, Ionic gelation, Microbeads, Ranolazine,

One-step immunoassay based on filtration for detection of food poisoning-related bacteria

A one-step immunoassay based on filtration was presented, which used microbeads for target analyte detection and filters with appropriate pore sizes to distinguish the complexity of target analyte and microbeads. For effective bacterial detection, the microbead size and the filter's pore size must be optimized. The optimal concentrations of the enzyme (urease) and antibody were determined at the maximum absorbance change, that is, the maximum pH change. The pH change was measured using a field-effect transistor (FET). The correlation between pH change and threshold voltage was estimated to be 21.7 mV/pH, and the correlation between pH change and the source-drain current was estimated to be −379 nA/pH. For the one-step immunoassay, antibodies against target bacteria were isolated from horse serum by filtration, and these antibodies were estimated to have a sufficiently high specificity to overcome cross-reactivity among five types of food poisoning-related bacteria: Escherichia coli O157, Salmonella typhimurium, Listeria monocytogenes, Bacillus cereus, and Staphylococcus aureus. Finally, the FET-based one-step immunoassay was demonstrated for five types of food poisoning-related bacteria in human serum.

Non-Microplastic Microbeads From Sago Liquid Waste With The Addition Of Chitosan as Antibacterial Function: A Review

Plastic has many advantages due to flexibility, unaffordable, transparent, and toughness. Plastics can size into small sizes (microplastics) or large sizes (macroplastics). Microbeads are granules of plastic or fiber that can often be utilized in many personal care products with sizes below 1 mm. These size of microbeads affect to environmental. Microbeads cannot be filtered by the sewage treatment system resulting microbeads go through to end up in water bodies and become a dangerous pollutant. Therefore any efforts must be conducted to replace the use of plastics microbeads. The microbeads can be prepared from with organic materials having easily degradation with stand the same functions. One of the ways can be accomplished through preparation of bacterial cellulose from sago waste since liquid waste can be used to produce bacterial cellulose. Bacterial cellulose is highly potential to be developed into microbeads as it has advantages of high purity, good tissue structure, high degradation ability, mechanical strength, and easy degradability. The utilization of sago liquid waste is very beneficial because it can reduce environmental pollution and production costs. Additionally, antibacterial properties in microbeads can introduce chitosan, eucalyptus filtrate, celery leaf extract, basil, and cinnamon. The use of chitosan as an additive in the preparation of microbeads will reduce the rate of water adsorption, improve mechanical properties, and reduce the moisture in the microbeads that would promote the ability of microbeads to against bacteria.

Highly efficient microencapsulation of phytonutrients by fractioned cellulose using biopolymer complexation technology.

A poorly water soluble polar and non-polar bioactive complexes encapsulated in a nanocellulose-based polymeric network are the focus of this research. Ascorbic acid, resveratrol, holy basil extract, pomegranate extract, and niacin are all microencapsulated bioactive complexes that make up Zetalife®, a nutritional ingredient. It uses an interpenetrating polymeric network (IPN) with more dispersed nanocellulose and phospholipids to increase Zetalife® s bioavailability. Field Emission Scanning Electron Microscopic (FESEM) images were used in studying the morphology of encapsulated bioactive molecules. The average microbead size was determined to be 244.2nm. After each month of storage, the sample's microbial content was measured to assess stability. In vitro release followed a first-order kinetic model with high R2.

PREPARATION AND EVALUATION OF GELLAN GUM-LINSEED GUM BLEND MICROBEADS FOR SUSTAINED RELEASE OF ACECLOFENAC

Objective: The objective of the current investigation was to design aceclofenac encapsulated microbeads using gellan gum and linseed gum blends following ionotropic gelation by trivalent Al3+-ions as cross-linking agent. Methods: Various formulation parameters like polymer-polymer blend (gellan gum and linseed gum), proportion and concentration of aluminium chloride (i.e., cross-linker) were considered for preparation of different formulations. In vitro aceclofenac release from these microbeads was performed in 0.1 N HCl (pH 1.2) for a preliminary 2 h, and after this period, it was continued in phosphate buffer (pH 7.4) for the next 6 h (a total of 8 h). Results: These gellan gum-linseed gum microbeads of aceclofenac exhibited drug encapsulation efficiency of 27.70 ± 0.42 to 74.27±2.57 % and average sizes of gellan gum-linseed gum microbeads were ranged 739.57 ± 22.70 to 968.07 ± 42.24 µm. The release of drug (in vitro) from these gellan gum-linseed gum microbeads of aceclofenac demonstrated a sustained pattern of drug-releasing (over 8 h). Conclusion: These gellan gum-linseed gum microbeads can be used as an effectual option of polymeric carrier matrices for sustained release.

Co‐extrusion and extrusion microencapsulation: Effect on microencapsulation efficiency, survivability through gastrointestinal digestion and storage

AbstractProbiotic is a functional food ingredient that is commonly used in the manufacturing of fermented dairy products and vegetable‐based foods. The consumption of probiotics has been claimed to confer health benefits to the host. However, probiotic cells are sensitive to harsh environments such as extreme pH and enzymes in the gastrointestinal tract. Hence, the microencapsulation technique is often adopted to shield probiotics from the outer environment. This review introduces a more advanced extrusion technique called co‐extrusion, which has been used to microencapsulate probiotics over the last few years. Both co‐extrusion technique and extrusion technique in microencapsulating probiotics were discussed extensively in this article. Furthermore, the impact of encapsulating probiotics in contrast with unencapsulated cells was also presented. This review highlighted some of the factors that might cause low viable cell count during microencapsulation and large microbead size. Lastly, the survivability of encapsulated probiotics in gastrointestinal digestion and storage under different temperatures were evaluated and the importance of probiotic microencapsulation was also emphasized.Practical ApplicationsThe detailed information on extrusion and co‐extrusion techniques for probiotics microencapsulation is presented in this review. This information is useful for researchers and industrialists in understanding and applying both encapsulation techniques on probiotics for different purposes. Through this paper, the readers would also gain more insight into the factors affecting the viability and microbead size of the encapsulated probiotic to further optimize the extrusion and co‐extrusion encapsulation process. Furthermore, the ideal storage temperature and additional drying process for the encapsulated probiotic identified in this review would open opportunities for industrialists to produce functional probiotic products with a high viable cell count.

Preparation of Poly(Ionic Liquid) Microbeads by Evaporation‐Assisted Phase Separation

Front Cover: In article number 2100379 by Jianbo Yin and co-workers, a facile and high yield evaporation-assisted phase separation method to prepare uniform PIL microbeads is reported. No stabilizer is used and the size of microbeads can be easily controlled by initial PIL/H2O mass ratio, liquid level height, and evaporation temperature.

Preparation of Poly(Ionic Liquid) Microbeads by Evaporation‐Assisted Phase Separation

AbstractThe authors reported a simple and high‐yield evaporation‐assisted phase separation (EAPS) method to prepare poly(ionic liquid) (PIL) microbeads, in particular submicron microbeads. Irregular PIL powder or bulk is dissolved in a theta solvent composed of volatile good solvent and less volatile non‐solvent at room temperature, and then PIL microbeads are formed by evaporation of the solution at a temperature lower than the boiling point of volatile good solvent. The yield of microbeads, in particular, submicron microbeads, prepared by the EAPS method can reach 99%. The mechanism of microbead formation is studied by tracing the nucleation and growth process by the light transmittance. The key parameters to control the size and morphology of microbeads are investigated and discussed.

Preparation of glass-like carbon with micrometer-sized pores by mixing thermosetting resin with thermoplastic microbeads

Glass-like carbon (GLC) is an agranular carbon material with a pseudo-glass-like appearance on the surface and fractured face. In this study, GLCs with numerous micrometer-sized pores were prepared by mixing thermosetting resins with two sizes of thermoplastic microbeads. For these GLCs, the carbonization yields and apparent densities decreased when they were mixed with microbeads. SEM results suggested that the surfaces and fracture faces of GLCs mixed with small beads possess smaller pores compared to those prepared with large beads. The electrical resistances of GLCs with small beads heat-treated at 1000 ℃ or above were almost unchanged compared to those of the neat GLCs.

Emulsion hydrogel microbeads encapsulating extractants prepared by O/W/O double Pickering emulsions for the recovery of Cu(II) from water

In a double emulsion, the cross contamination between internal and external phase is an unavoidable problem, which limits its widely application. This work focused on the preparation of the cross contamination-free O/W/O Pickering emulsions for the fabrication of Pickering emulsion hydrogel (PEHG) microbeads encapsulating copper extractants. KH-570 was used to hydrophobically modify silica for the stabilization of O/W Pickering emulsions. Batch and fixed-bed experiments were conducted for the recovery of Cu(Ⅱ) from water using PEHG microbeads. The results showed that the formed particle-polymer networks in oil-water interface strengthen the stability of O/W Pickering emulsions. The cross contamination ratio of O/W/O Pickering emulsions was reduced to less than 3% under preset conditions. The size of PEHG microbeads was controlled by adjusting the dosage of hydrophobic silica and the optimal diameter used in extraction was 1.8–2.2 mm. The extraction capacity of copper extractants in PEHG microbeads was 86.43 mg/g, with the operation time of 80 min (D = 1.8 mm). The fixed-bed extraction experiment was completed in 250 min and the stripping rate was 97.1%. Compared to previous work, the extractants in PEHG microbeads possessed a better utilization.