Characterization Of Microparticles Research Articles

The Behavior and Dispersion Characteristics of Microparticles under Reservoir Flipping

The Behavior and Dispersion Characteristics of Microparticles under Reservoir Flipping

Chemical properties of peat micro particles modified asphalt.

This study investigated the chemical properties of peat microparticles modified asphalt (Pt.M.A.). The originality of the study resides in the examination of the chemical characteristics of peat microparticles (Pt.) modified asphalt (Pt. M.A.) utilising FTIR, SEM, SFE, and XRD methodologies. This encompasses Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), surface free energy (SFE), and X-ray diffraction (XRD). Initially, FTIR examined the functional groups of both unaltered and altered asphalt binders. The SEM images reveal improved compatibility, showcasing superior diffusion of the modifier across the asphalt. A further critical factor is that improved adhesion properties, according to the SFE study, indicate that modified binders generally offer more SFE compared to unmodified binders. The XRD measurements revealed a semi-crystalline structure in the Pt. modifier and an amorphous structure in the basal asphalt binder. The integration of Pt. into the asphalt cement resulted in modifications to the phases of both constituents, culminating in the emergence of a new semi-crystalline phase inside the modified asphalt binder. These data suggest that peat microparticles (Pt.) can improve the efficacy of asphalt binders by enhancing compatibility, adhesion, and resistance to ageing.

Development, characterization, and comparison of chitosan microparticles as a carrier system for black bean protein hydrolysates with antioxidant capacity.

Peptides in black bean protein hydrolysates (BPHs) exert antioxidant capacity. However, peptides are prone to degradation during processing and digestion. Chitosan (Ch) can protect them and provide a delayed release. This work develops and compares two drying methods producing porous structured Ch microparticles (MPs) as carriers for antioxidant BPH. Ch gels were obtained by ionic gelation and dried by supercritical CO2 solvent displacement or fast-freeze-drying methods. The resulting aerogels and fast-freeze-dried MPs were structurally characterized, and their swelling and release profiles were obtained at pH 1.2 and 7.4. The antioxidant capacity of systems was determined by 2,2'-azino-bis(3-ethyl-benzthiazoline-6-sulphonic acid) (ABTS) and superoxide radical assays. The results showed BPH-Ch best complexation conditions occurring at a pH of 4.5 and a 4:1 BPH/Ch ratio. The particle size of the complex was 1047.6nm, and the entrapment efficiency and loading capacity were 28.2% and 54.3%, respectively. At pH 1.2 and 7.4, the release rate of BPH was lower in aerogel than in fast-freeze-dried MPs. Besides, entrapment BPH in Ch significantly reduced the ABTS antioxidant activity IC50 from 35.1µM Trolox equivalents (TE)/mg to 250.7 and 406.2µM TE/mg for Ch fast-freeze-dried and aerogels, respectively. Superoxide radical inhibition IC50 ranged from 74.6 to 92.9mM ascorbic acid equivalents/mg in the different samples. BPH-loaded aerogels presented lower specific surface area (94.7 vs. 138.6m2/g, p<0.05) and higher average pore size (26.4 vs. 19.8nm) than Ch aerogels. Ch aerogel is a promising carrier for delaying the release of common bean antioxidant peptides useful for developing functional foods. PRACTICAL APPLICATION: This novel system could act as an ingredient to incorporate antioxidant compounds in different formats to develop delayed-release nutraceuticals and functional foods, such as bakery, dairy products, or beverages. Along, antioxidant peptide-loaded aerogels could be used as a slow-release system for compounds acting as natural preserving antioxidants for food applications such as raw meat products or high-fat foods.

Seasonal variation in characteristics of wear microparticles of high density (> 1.8 g cm−3) produced on road

Wear microparticles are produced on roads by traffic, and they can be transferred to rivers and seas settling as sediments. The sedimentation rate increases with increasing particle density and size. In this study, the types and amounts of high-density wear microparticles (HDWPs, >1.8 g cm−3) in road dust were investigated. The HDWPs ranging from 106 to 1000 μm were classified into eight categories depending on the color, shape, and physical property: mineral particles (MPs), asphalt pavement wear particles (APWPs), glass particles (GPs), glass beads (GBs), tire-road wear particles (TRWPs), plant-related particles (PRPs), road paint wear particles (RPWPs), and plastic particles (PPs). The HDWPs in road dust were the most abundant in winter (94.0–95.6 wt%), while being the lowest in spring (82.7–90.7 wt%). MPs accounted for over 50 wt% of the HDWPs; however, TRWPs were not found in HDWPs larger than 200 μm. The HDWPs produced by the abrasion of roads, including asphalt pavements and marking paint, exceeded 90 wt%. The non-crosslinked organic components in the HDWPs were removed by chloroform treatment. The chloroform-soluble components in the HDWPs were much more present in winter than in other seasons. Swelling TRWPs with chloroform released mineral particles on the surface.

TCT-938 Identification and Characterization of Microparticles and Microorganisms in Blood Clots of STEMI Patients: A Comparative Study of Rescue and Primary Angioplasty

TCT-938 Identification and Characterization of Microparticles and Microorganisms in Blood Clots of STEMI Patients: A Comparative Study of Rescue and Primary Angioplasty

3D inkjet printing of hybrid electroactive ink based on molecularly imprinted polymers for lipopolysaccharides detection

A hybrid electroactive ink based on molecularly imprinted polymer (MIP) hollow microparticles, zinc oxide nanoparticles (ZnO NPs) and conductive carbon paste (CP) is reported herein for the first time. The MIP/ZnO NPs/CP and corresponding non-imprinted NIP/ZnONPs/CP modified inks were screen-printed on plastic substrates via 3D inkjet technology to cover around 40 working screen-printed carbon electrodes (SPCE) pieces in a single batch. The custom-made electrochemical MIP/ZnONPs/CP@SPCE sensor was designed for the detection of bacterial endotoxins, i.e., lipopolysaccharides (LPS), derived from Pseudomonas aeruginosa. Hollow MIP silica microparticles with specific properties for 3D printing application, in terms of granulation and morphology, were synthesized via sol-gel method using tetraethyl orthosilicate and (3-aminopropyl) triethoxysilane as monomers. Following the structural and morphological characterization of microparticles, the evaluation of template rebinding indicated a clear specificity of MIPs for LPS compared to the NIPs. Hybrid MIP/ZnONPs/CP and NIP/ZnONPs/CP inks were characterized using morphological and structural methods, which confirmed a viscosity of 25.000 mPa.s, a granulation of <20 µm, and a solid powder content of <27 %, as well as a homogenous incorporation of MIP particles and ZnONPs in the conductive CP. Finally, the electrochemical evaluation of the modified MIP/ZnONPs/CP@SPCE sensor revealed a good sensitivity to LPS molecules in PBS at pH 7.4, in the linear working range 1 - 100 µM, where a 0.058 µM limit of detection (LOD) and a response time less than or equal to 1 min were determined. The selectivity of the MIP/ZnONPs/CP@SPCE sensor towards LPS from Salmonella enterica and Escherichia coli was also assessed, highlighting a clear difference between these structural resembling species.

Characterization and ecotoxicity of microparticles from polyurethane foam and Luffa cylindrica in Daphnia magna and Artemia salina

Characterization and ecotoxicity of microparticles from polyurethane foam and Luffa cylindrica in Daphnia magna and Artemia salina

IRON-BASED SPIKY MICROSPHERES SYNTHESIZED USING OXALATE VIA ONE-STEP HYDROTHERMAL PROCESS — PRESENCE OF HUMBOLDTINE

In this study, novel iron-based spiky microparticles (approximately 1–2[Formula: see text][Formula: see text]m in diameter) were synthesized using iron oxalate precursors using a straightforward one-step hydrothermal reaction. The microparticles’ morphological, mineralogical and chemical properties were investigated using scanning electron microscopy (SEM), X-ray diffractometry (XRD), Raman spectroscopy and UV-Vis spectroscopy. The physico-chemical characteristics of spiky microparticles were also compared with cubic iron microparticles synthesized using standalone iron as well as with the addition of glycine. XRD and Raman analyses identified substantial presence of humboldtine, a type of ferrous oxalate dehydrate mineral, in the resultant yellowish solid hydrothermal product. The mechanism involving reactions of species in the hydrothermal process was described herein. The results described in this study afford vital insights into the design of iron oxalate-based microparticles synthesis processes.

Development and characterization of spray-drying microparticles loaded with chestnut shells extract: New insights for oral mucositis therapy

Chestnut shells (CS) are fruit by-products with a high content of (poly)phenols that may play a key role in the oral mucositis (OM) pathogenesis. OM is an inflammatory condition and a common side effect of oncological treatments, being characterized by painful ulceration, difficulty in swallowing and speaking, and an increased risk of infection that can compromise the primary treatment outcome. Natural antioxidants have emerged as an interesting approach to the prevention and treatment of OM by inhibiting the redox imbalance responsible for its development. To overcome the instability and poor water solubility of (poly)phenols, CS extract was encapsulated by spray-drying. The results attested the successful microencapsulation with a product yield of 44%, a total phenolic content of 9.73 mg GAE/g, an antioxidant activity of 91.76 μmol FSE/g and an antiradical ability of 7.83 mg TE/g. FTIR results showed successful encapsulation. The CS-loaded microparticles revealed a median size of 1.95 μm (Dv50), a moisture content of 4.33% and a swelling capacity of 98.16%. The thermal properties of the extract were preserved, while rheological studies evidenced the microparticles pseudoplastic behavior. The microparticles safety was demonstrated through experiments on oral epithelial cell lines, where no adverse effects were observed at concentrations up to 1 mg/mL. Additionally, the (poly)phenols permeation, such as vanillin, succinic acid, protocatechuic acid, pyrocatechol, and 4-hydroxybenzoic acid, was confirmed by LC-HRMS using an in vitro buccal model. This study demonstrated the potential application of CS-loaded microparticles for the prevention/treatment of OM.

Characterization of HDPE microparticles in sludge aerobic digestion and their influence on the process

The occurrence of microplastics (MPs) in wastewater has been studied in the last years. The high efficiency of their removal from wastewater is linked to their transfer to the sludge. In this work, the effect of high-density polyethylene (HDPE) on aerobic digestion was evaluated and these MPs were monitored, characterizing them by three different techniques. Two parallel batch digesters were monitored. AD-Control (meaning Aerobic Digester) operated as a reference, with no external HDPE particles, whereas these polymeric fragments were introduced to the second aerobic digester (AD-HDPE) using ring pulls as microplastic support. FTIR, Raman spectroscopies and fluorescence analysis of these microparticles showed some relevant results that should be highlighted. Higher fluorescence appeared after 7 days in the digester. It coincided with an increase of active volatile suspended solids (AVSS) in the AD-HDPE, which means that an increase of the microbial activity took place. Despite the presence of HDPE particles in the sludge, the digester performance was not compromised. Besides, the HDPE particles did not affect the microbial diversity (Shannon index) of the bacterial community at the end of the experiment compared to the bacterial community of the aerobic digester control tank. Based on the analysis of the relative abundances of microbial taxa, it was concluded that HDPE had selective effects on sludge microbial community, increasing the relative abundance of Bacteroridota phylum.

Study on the procoagulant characteristics of microparticles in acute myocardial infarction

To investigate the characteristic of circulating microparticle in patients with acute myocardial infarction (AMI) and its possible mechanism of promoting coagulation. A prospective case-control study was conducted. The patients with coronary heart disease admitted to the second department of cardiology in Harbin First Hospital from June to November 2023 were enrolled, and they were grouped according to whether the patients occurred AMI or not. On the day of admission, disseminated intravascular coagulation (DIC) score was calculated. At the same time, fasting venous blood was collected, and the levels of D-dimer, fibrin degradation product (FDP) and the activities of major coagulation factors were detected. The level of circulating microparticle was determined by microparticle trapping method. The microparticle carrying tissue factor (TF+MP) level was detected by tissue factor (TF) dependent F Xa production assay. Spearman correlation method was used to analyze the correlation among the indicators. A total of 52 patients with coronary heart disease were enrolled, including 26 patients in AMI group and 26 patients in non-AMI group. There was no significant difference in gender, age, body mass index (BMI), underlying diseases, smoking history, and pre-admission treatment of patients between the two groups, indicating that the baseline data of the two groups were balanced and comparable. Compared with the non-AMI group, the DIC score and D-dimer, FDP levels in the AMI group were significantly increased [DIC score: 3 (3, 4) vs. 3 (2, 3), D-dimer (mg/L): 8.80 (6.84, 15.66) vs. 2.13 (1.64, 3.86), FDP (mg/L): 30.13 (19.30, 52.54) vs. 20.00 (13.51, 28.37), all P < 0.01], indicating that the degree of coagulation activation in AMI patients was more severe. The consumption of major coagulation factors in the coagulation pathway in the AMI group was heavier than that in the non-AMI group [F II: 59.45% (49.65%, 71.25%) vs. 63.65% (49.98%, 73.22%), F V: 96.95% (73.50%, 112.78%) vs. 105.05% (73.48%, 131.48%), F VII: 42.30% (36.98%, 51.98%) vs. 53.40% (46.58%, 69.88%), F X: 60.90% (48.22%, 80.82%) vs. 73.50% (56.80%, 85.98%), F XI: 82.45% (62.90%, 99.10%) vs. 92.40% (73.90%, 114.25%), F XII: 29.90% (12.42%, 42.38%) vs. 34.65% (16.32%, 48.20%), all P < 0.05]. The circulating TF+MP level in the AMI group was significantly higher than that in the non-AMI group [nmol/L: 0.13 (0.06, 0.20) vs. 0.08 (0.04, 0.15), P < 0.05]. There was no significant difference in the level of circulating microparticle between AMI group and non-AMI group [nmol/L: 1.24 (0.71, 3.77) vs. 1.35 (0.73, 2.14), P > 0.05]. Correlation analysis showed that circulating TF+MP level in the patients with coronary heart disease was significantly positively correlated with coagulation indicator DIC score (r = 0.307, P = 0.027), D-dimer (r = 0.696, P < 0.001) and FDP (r = 0.582, P < 0.001), and there was a strong negative correlation with exogenous pathway factor F VII (r = -0.521, P < 0.001) and common pathway factor F X (r = -0.332, P = 0.016). The circulating TF+MP level in AMI patients was significantly higher than that in the non-AMI patients. TF+MP may play an important role in activating the extrinsic coagulation pathway, exacerbating coagulation factor consumption, and promoting clot formation during AMI occurrence.

Interaction of Serum and Plasma Proteins with Polyelectrolyte Microparticles with Core/Shell and Shell-Only Structures.

Polyelectrolyte microparticles (MPs) synthesized on calcium carbonate cores are considered a promising basis for new drug delivery systems. It is known that microparticles entering a physiological environment absorb proteins on their surface, which can change the properties of the microparticles and alter their functional activity. This study aimed to compare the compositions of the adsorbed protein layer formed on microparticles with the core/shell and shell structures obtained by layer-by-layer deposition. The difference in the microparticle structure was associated with changes in their surface topography and ζ-potential. These microparticles were incubated with human serum or plasma at 37°C for 24 h. The adsorbed proteins were eluted and analyzed by means of SDS-PAGE. The protein composition of the eluates was determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS); a total of 357 proteins were identified, and 183 of them were detected in all samples. Our results demonstrate that the relative abundance of proteins of different functional groups (immunoglobulins, complement proteins, and apolipoproteins) varied depending on the structure and surface characteristics of the polyelectrolyte microparticles and the incubation medium. Our findings expand the understanding of the influence of the physicochemical properties of the microparticles on their interaction with proteins, which can help to improve the design of microparticles for drug delivery.

Synthesis and Characterisation of Core-Shell Microparticles Formed by Ni-Mn-Co Oxides.

In this work, core and core-shell microparticles formed by Ni-Mn-Co oxides with controlled composition were fabricated by an oxalate-assisted co-precipitation route, and their properties were analysed by diverse microscopy and spectroscopy techniques. The microparticles exhibit dimensions within the 2-6 μm range and mainly consist of NiO and NiMn2O4, the latter being promoted as the temperature of the treatment increases, especially in the shell region of the microparticles. Aspects such as the shell dimensions, the vibrational modes of the spinel compounds primarily observed in the shell region, the oxidation states of the cations at the surface of the microparticles, and the achievement of a Ni-rich 811 core and a Mn-rich 631 shell were thoroughly evaluated and discussed in this work.

Macroplastic and Microparticle Pollution in Beach Sediments from Urias Coastal Lagoon (Northwest Mexico).

This study investigates the occurrence and characteristics of macroplastic and polymer microparticles in the Urias coastal lagoon's beach sediments, in northwest Mexico. Coastal lagoons, productive and vulnerable ecosystems, are impacted significantly by anthropogenic activities, leadings to their pollution by various contaminants, including plastics. Our research involved sampling sediments from four sites within the lagoon that were influenced by different human activities such as fishing, aquaculture, thermoelectric power plant operations, industrial operations, and domestic wastewater discharge. Our methodology included collecting macroplastics and beach sediment samples, followed by laboratory analyses to identify the plastic debris' size, shape, color, and chemical composition. The results indicated a notable presence of macroplastic items (144), predominantly bags, styrofoam, and caps made of polyethylene (PE), polypropylene (PP), and polyethylene terephthalate (PET). The polymer microparticles were mainly fibers, with cotton and polyester as the most common polymers, suggesting a significant contribution from clothing-related waste. The dominant colors of the microparticles were blue and transparent. High densities were observed in areas with slower water exchange. Our findings highlight the urgent need for better waste management practices to mitigate plastic pollution in coastal lagoons, preserving their ecological and economic functions.

Application of Quality by Design in the Development of Hydrogen Sulfide Donor Loaded Polymeric Microparticles

Hydrogen sulfide (H2S) is a multifaceted gasotransmitter molecule which has potential applications in many pathological conditions including in lowering intraocular pressure and providing retinal neuroprotection. However, its unique physicochemical properties pose several challenges for developing its efficient and safe delivery method system. This study aims to overcome challenges related to H2S toxicity, gaseous nature, and narrow therapeutic concentrations range by developing polymeric microparticles to sustain the release of H2S for an extended period. Various formulation parameters and their interactions are quantitatively identified using Quality-by-Design (QbD) approach to optimize the microparticle-based H2S donor (HSD) delivery system. Microparticles were prepared using a solvent-evaporation coacervation process by using polycaprolactone (PCL), soy lecithin, dichloromethane, Na2S.9H2O, and silicone oil as polymer, surfactant, solvent, HSD, and dispersion medium, respectively. The microparticles were characterized for size, size distribution, entrapment efficiency, and H2S release profile. A Main Effects Screening (MES) and a Response Surface Design (RSD) model-based Box-Behnken Design (BBD) was developed to establish the relationship between critical process parameters (CPPs) and critical quality attributes (CQAs) qualitatively and quantitatively. The MES model identified polymer to drug ratio and dispersion medium quantity as significant CPPs among others, while the RSD model established their quantitative relationship. Finally, the target product performance was validated by comparing predicted and experimental outcomes. The QbD approach helped in achieving overall desired microparticle characteristics with fewer trials and provided a mathematical relationship between the CPPs and the CQAs useful for further manipulation and optimization of release profile up to at least 30 days.Graphical

Platelet-derived microvesicles in cardiovascular diseases

Extracellular vesicles (EVs) are a family of particles/vesicles present in blood and body fluids, bounded by a lipid dual- layer and non-replicable. They do not contain a functional core and carry a variety of molecules important in mediating cellular communication, thereby modulating crucial cellular processes such as homeostasis, induction/attenuation of inflammation, and support of cellular repair.Their existence, initially suspected in 1946 and confirmed in 1967, led to a sudden increase in the number of scientific publications, given their potential significance in understanding the mechanisms underlying various diseases, such as cancer, cardiovascular, metabolic, neurological diseases and infectious. These researches revealed a role for EVs as promising candidate biomarkers for diagnosis, prognosis, and even therapeutic purposes.The population of platelet-derived vesicles (pEVs) is the largest among other types of circulating EVs.Cell membrane physical characteristics and biological burden define the pivotal role of platelet-derived vesicles in the pathogenesis of cardiovascular (CV) diseases.Platelet-derived EVs are, therefore, key players in mediating inflammatory and coagulation reactions involving endotheliocytes, platelets, smooth muscle cells and inflammatory cells and thus contribute to the development ofatherosclerosis and angiogenesis, dysregulation of the coronary microcirculation in contiguity with endothelial dysfunction. In addition, EVs play an essential role in tissue repair, angiogenesis, and neovascularization through intracellular signaling cascades. In fact, EVs mediate autocrine and paracrine signals that are able to rebuild the homeostatic microenvironment in the heart and vessels.This review aims to provide a brief overview of the biogenesis, characteristics of platelet micro-particles with a special focus on their involvement in cardiovascular disease, but especially on the link between thrombosis, endothelial dysfunction and inflammation.In addition, here we review early experiments, summarize key findings that propelled the field, describe the growth of an organized EV community, and discuss the current state of the field.

#2229 miR-186, a potential noninvasive diagnostic biomarker of Membranous nephropathy in urinary microparticles

Abstract Background and Aims Membranous nephropathy (MN) is one of the most common causes of nephrotic syndrome, and is associated with podocyte damage and proteinuria. Invasive biopsy is the gold-standard diagnostic method for this disease. The use of specific biomarkers, such as microparticles (MPs) originating from damaged podocytes released in a patient's urine, has been proposed as an early, noninvasive, and repetitive diagnostic method. According to the previous studies, MPs derived from podocytes are present in the urine of patients with different glomerulonephritis, such as diabetic nephropathy, lupus nephritis, renal injury in preeclampsia, and renovascular hypertensive disorders. The analysis of urinary microparticle-derived miRNAs from patients with kidney diseases can help detect diagnostic biomarkers. This study aimed to analyze podocyte damage-related miRNAs in MN, miR-30c, miR-135, and miR-18 in the urinary MP of MN patients to identify appropriate candidate biomarkers for MN Method Urine samples from 30 patients with membranous nephropathy and 16 healthy individuals were collected to extract podocyte MPs using ultracentrifugation. Characterization of these particles was determined using the specific protein marker of MPs, TSG-101, and the podocyte-specific marker Nephrin, by western blotting, and SEM was used to check the size and morphology. The expression levels of microRNAs extracted from podocyte MPs, miR-30c, miR-135, and miR-186, were also evaluated by real-time PCR. Results The evaluation of the characteristics of MPs showed that there were many particles with a size of more than 100 nm in the urine sample, and there were higher levels of the specific markers TSG-101 and Nephrin in the urine samples of MGN patients than in the control samples (P &amp;lt; 0.001). The expression level of miR-186 was compared between the three studied groups and based on the results of the expression of this miRNA in the group of membranous nephropathy patients compared to healthy people group, there was a significant increase in expression (P = 0.000) Conclusion This study showed that although the expression levels of miR-186 in podocyte MPs samples extracted from the urine of patients with MN were significantly changed compared to the studied controls, more studies should be performed to determine the diagnostic values.

Effects of hydrogen permeation on the mechanical characteristics of electroless nickel-plated free-cutting steel for application to the hydrogen valves of hydrogen fuel cell electric vehicles

Electroless nickel plating is a suitable technology for the hydrogen industry because electroless nickel can be mass-produced at a low cost. Investigating in a complex environment where hydrogen permeation and friction/wear work simultaneously is necessary to apply it to hydrogen valves for hydrogen fuel cell vehicles. In this research, the effects of hydrogen permeation on the mechanical characteristics of electroless nickel-plated free-cutting steel (SUM 24L) were investigated. Due to the inherent characteristics of electroless nickel plating, the damage (cracks and delamination of grain) and micro-particles by hydrogen permeation were clearly observed at the grain boundaries and triple junctions. In particular, the cracks grew from grain boundary toward the intergranualr. This is because the grain boundaries and triple junctions are hydrogen permeation pathways and increasing area of the hydrogen partial pressure. As a result, its surface roughness increased by a maximum of two times, and its hardness and adhesion strength decreased by hydrogen permeation. In particular, hydrogen permeation increased the friction coefficient of the electroless nickel-plated layer, and the damage caused by adhesive wear was significantly greater, increasing the wear depth by up to 5.7 times. This is believed to be due to the decreasing in wear resistance of the electroless nickel plating layer damaged by hydrogen permeation. Nevertheless, the Vickers hardness and the friction coefficient of the electroless nickel plating layer were improved by about 3 and 5.6 times, respectively, compared with those of the free-cutting steel. In particular, the electroless nickel-plated specimens with hydrogen embrittlement exhibited significantly better mechanical characteristics and wear resistance than the free-cutting steel.

Enhancing Encapsulation Efficiency of Chavir Essential Oil via Enzymatic Hydrolysis and Ultrasonication of Whey Protein Concentrate-Maltodextrin.

This study focused on the characterization of emulsions and microparticles encapsulating Chavir essential oil (EO) by application of modified whey protein concentrate-maltodextrin (WPC-MD). Different physical, chemical, morphological, thermal, and antioxidant properties and release behavior of spray-dried microparticles were assessed. Antioxidant, solubility, emulsifying, and foaming activities of modified WPC were increased compared to those of primary material. The results indicated that the particle size distribution varied depending on the type of carriers used, with the smallest particles formed by hydrolyzed WPC (HWPC). Binary blends of modified WPC-MD led to improved particle sizes. The spray-drying yield ranged from 64.1% to 85.0%, with higher yields observed for blends of MD with sonicated WPC (UWPC). Microparticles prepared from primary WPC showed irregular and wrinkled surfaces with indentations and pores, indicating a less uniform morphology. The UWPC as a wall material led to microparticles with increased small cracks and holes on their surface. However, HWPC negatively affected the integrity of the microparticles, resulting in broken particles with irregular shapes and surface cracks, indicating poor microcapsule formation. Encapsulating EO using WPC-MD increased the thermal stability of EO significantly, enhancing the degradation temperature of EO by 2 to 2.5-fold. The application of primary WPC (alone or in combination with MD) as wall materials produced particles with the lowest antioxidant properties because the EO cannot migrate to the surface of the particles. Enzymatic hydrolysis of WPC negatively impacted microparticle integrity, potentially increasing EO release. These findings underscore the crucial role of wall materials in shaping the physical, morphological, thermal, antioxidant, and release properties of spray-dried microparticles, offering valuable insights for microencapsulation techniques.

Microplastics suspended in dust from different indoor environments in Barranquilla, Colombia: Predominant microparticles?

Considering that microplastics (MPs) are classified as ubiquitous pollutants, that air quality affects human health, and that people remain indoors most of the time, the need has arisen to evaluate the exposure to MPs within the suspended dust in indoor environments. With this objective, the present study carried out passive sampling to analyze the precipitation of microparticles in some indoor residential environments (2 apartments) and workplaces (an office, a pastry shop, a gift shop, and a paint shop) in Barranquilla, Colombia. The quantification and physical characterization of microparticles were carried out under a stereomicroscope, and the chemical characterization was carried out by infrared microspectroscopy (μFTIR). The highest average concentration of MPs in the apartments was found in the air-conditioned rooms (1.1 × 104 MP/m2/day), and concerning the workplaces, the gift shop and the paint shop were the spaces with a higher proportion of MPs (6.0–6.1 × 103 MP/m2/day), with polyesters being the main synthetic polymers, but being semi-synthetic particles the predominant among the samples. Regarding its morphology, fibers were the most abundant shape (>90%), grouping mainly in the 1000–5000 μm range, while the few fragments found were mostly grouped below 50 μm. Exposure by inhalation of MPs in adults was estimated between 1.7 × 102–1.6 × 103 MP/kg/day, while by ingestion it ranged between 2.7 × 102–2.4 × 103 MPs/kg/day. On the other hand, within our research, a significant presence of non-plastic microparticles was found, which reached up to 69% in analyzed samples, corresponding mainly to cotton and cellulose, so we suggest that these should also be included in future studies that aim to estimate potential health implications from exposure to suspended micropollutants.