Interactive effects between water temperature, microparticle compositions, and fiber types on the marine keystone species Americamysis bahia.

Recently, there has been an increasing emphasis on examining the ecotoxicological effects of anthropogenic microparticles (MPs), especially microplastic particles, and related issues. Nevertheless, a notable deficiency exists in our understanding of the consequences on marine organisms, specifically in relation to microfibers and the combined influence of MPs and temperature. In this investigation, mysid shrimp (Americamysis bahia), an important species and prey item in estuarine and marine food webs, were subjected to four separate experimental trials involving fibers (cotton, nylon, polyester, hemp; 3 particles/ml; approximately 200 µm in length) or fragments (low-density Polyethylene: LDPE, polylactic acid: PLA, and their leachates; 5, 50, 200, 500 particles/ml; 1-20 µm). To consider the effects in the context of climate change, three different temperatures (22, 25, and 28 °C) were examined. Organismal growth and swimming behavior were measured following exposure to fragments and microfibers, and reactive oxygen species and particle uptake were investigated after microfiber exposure. To simulate the physical characteristics of MP exposure, such as microfibers obstructing the gills, we also assessed the post-fiber-exposure swimming behavior in an oxygen-depleted environment. Data revealed negligible fragment, but fiber exposure effects on growth. PLA leachate triggered higher activity at 25 °C and 28 °C; LDPE exposures led to decreased activity at 28 °C. Cotton exposures led to fewer behavioral differences compared to controls than other fiber types. The exposure to hemp fibers resulted in significant ROS increases at 28 °C. Microfibers were predominantly located within the gastric and upper gastrointestinal tract, suggesting extended periods of residence and the potential for obstructive phenomena over the longer term. The combination of increasing water temperatures, microplastic influx, and oxidative stress has the potential to pose risks to all components of marine and aquatic food webs.

Polymer Backpack-loaded Tissue Infiltrating Monocytes for Treating Cancer.

Adoptive cell therapies are dramatically altering the treatment landscape of cancer. However, treatment of solid tumors remains a major unmet need, in part due to limited adoptive cell infiltration into the tumor and in part due to the immunosuppressive tumor microenvironment. The heterogeneity of tumors and presence of non-responders also calls for development of antigen-independent therapeutic approaches. Myeloid cells offer such an opportunity, given their large presence in the immunosuppressive tumor microenvironment, such as in triple negative breast cancer. However, their therapeutic utility is hindered by their phenotypic plasticity. Here, we leverage the impressive trafficking ability of adoptively transferred monocytes into the immunosuppressive 4T1 tumor to develop an anti-tumor therapy. To control monocyte differentiation in the tumor microenvironment, we developed surface-adherent "backpacks" stably modified with IFNγ to stimulate macrophage plasticity into a pro-inflammatory, anti-tumor phenotype, a strategy we refer to as Ornate Polymer-backpacks on Tissue Infiltrating Monocytes (OPTIMs). Treatment with OPTIMs substantially reduced tumor burden in a mouse 4T1 model and significant increased survival. Cytokine and immune cell profiling revealed that OPTIMs remodeled the tumor microenvironment into a pro-inflammatory state. This article is protected by copyright. All rights reserved.

Fish Burgers Fortified with Microencapsulated Sacha Inchi Oil: Effects on Technological and Sensory Properties.

The long-chain omega-3 fatty acids alpha linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) have proven health benefits, but it is not common to find them together in a processed food product. This could lead to healthier and more functional food products, which may have positive implications for consumer health and well-being. This work aimed to fortify a model burger manufactured with fillets of an Amazonian fish (boquichico, Prochilodus nigricans) by adding microencapsulated sacha inchi oil (Plukenetia volubilis, rich in ALA) (MSIO) produced by spray-drying. MSIO was incorporated into the burgers at different levels (0, 3, 4, 5, and 6%). The burgers were characterized by their proximal composition, cooking losses, texture profile, lipid oxidation, sensory profile, overall liking, and fatty acid profile. The results showed that adding MSIO up to concentrations of 5% or 6% increased the instrumental hardness, chewiness, and lipid oxidation in the burgers. However, fortifying the burgers with 3% MSIO was possible without affecting the burgers' sensory properties and overall liking. Regarding the fatty acid profile, the burgers with 3% MSIO had a higher content of polyunsaturated fatty acids, with the ALA, EPA, and DHA types of fatty acids. Therefore, we recommend using this fortification concentration, but future studies should be carried out to improve the oxidative stability of MSIO and the burgers.

Anionic Methacrylate Copolymer Microparticles for the Delivery of Myo-Inositol Produced by Spray-Drying: In Vitro and In Vivo Bioavailability.

In this study, a new micro delivery system based on an anionic methacrylate copolymer, able to improve the biological response of myo-inositol by daily oral administration, was manufactured by spray-drying. It has an ideal dose form for oral administration, with an experimental drug loading (DL)% of 14% and a regulated particle size of less than 15 µm. The new formulation features an improvement on traditional formulations used as a chronic therapy for the treatment of polycystic ovary syndrome. The microparticles' release profile was studied and ex vivo porcine intestinal mucosa permeation experiments were performed to predict potential improvements in oral absorption. Batch n. 3, with the higher Eudragit/MI weight ratio (ratio = 6), showed the best-modified release profiles of the active ingredient, ensuring the lowest myo-inositol loss in an acidic environment. The in vivo evaluation of the myo-inositol micro delivery system was carried out in a rat animal model to demonstrate that the bioavailability of myo-inositol was increased when compared to the administration of the same dosage of the pure active ingredient. The AUC and Cmax of the loaded active molecule in the micro delivery system was improved by a minimum of 1.5 times when compared with the pure substance, administered with same dosage and route. Finally, the increase of myo-inositol levels in the ovary follicles was assessed to confirm that a daily administration of the new formulation improves myo-inositol concentration at the site of action, resulting in an improvement of about 1.25 times for the single administration and 1.66 times after 7 days of repeated administration when compared to pure MI.

Stabilizing interactions of casein microparticles after a thermal post-treatment.

Casein microparticles from milk are important carrier materials for bioactive substances with stability and swelling properties that can be influenced by heat treatment. Microparticles produced by depletion flocculation and film drying remain stable in acidic media but swell and disintegrate under slightly alkaline conditions. Heat treatment after formation can stabilize the microparticles via a disulfide bridge network and newly formed hydrophobic contacts. Temperatures >60 °C are required so that denatured whey protein initiate formation of disulfide bridges via thiol exchange reactions. The particles then swell in a two-step process and exhibit an overshooting effect. If formation of disulphide bridges is prevented during heat treatment by adding N-methylmaleimide, overshooting swelling disappears and microparticles continue to expand instead. The analysis with parallel system dynamics models is based on the swelling of uncross-linked caseins, which is limited by the expansion capacity of cross-linked caseins.

Nanofunctionalized Microparticles for Glucose Delivery in Three-Dimensional Cell Assemblies.

Three-dimensional (3D) cell assemblies, such as multicellular spheroids, can be powerful biological tools to closely mimic the complexity of cell-cell and cell-matrix interactions in a native-like microenvironment. However, potential applications of large spheroids are limited by the insufficient diffusion of oxygen and nutrients through the spheroids and, thus, result in the formation of a necrotic core. To overcome this drawback, we present a new strategy based on nanoparticle-coated microparticles. In this study, microparticles function as synthetic centers to regulate the diffusion of small molecules, such as oxygen and nutrients, within human mesenchymal stem cell (hMSC) spheroids. The nanoparticle coating on the microparticle surface acts as a nutrient reservoir to release glucose locally within the spheroids. We first coated the surface of the poly(lactic-co-glycolic acid) (PLGA) microparticles with mesoporous silica nanoparticles (MSNs) based on electrostatic interactions and then formed cell-nanofunctionalized microparticle spheroids. Next, we investigated the stability of the MSN coating on the microparticles' surface during 14 days of incubation in cell culture medium at 37 °C. Then, we evaluated the influence of MSN-coated PLGA microparticles on spheroid aggregation and cell viability. Our results showed the formation of homogeneous spheroids with good cell viability. As a proof of concept, fluorescently labeled glucose (2-NBD glucose) was loaded into the MSNs at different concentrations, and the release behavior was monitored. For cell culture studies, glucose was loaded into the MSNs coated onto the PLGA microparticles to sustain local nutrient release within the hMSC spheroids. In vitro results demonstrated that the local delivery of glucose from MSNs enhanced the cell viability in spheroids during a short-term hypoxic culture. Taken together, the newly developed nanofunctionalized microparticle-based delivery system may offer a versatile platform for local delivery of small molecules within 3D cellular assemblies and, thus, improve cell viability in spheroids.

Persistent neuroinflammation and functional deficits in a murine model of decompression sickness.

We hypothesized that early intra-CNS responses in a murine model of decompression sickness (DCS) would be reflected by changes in the microparticles (MPs) that exit the brain via the glymphatic system, and due to systemic responses the MPs would cause inflammatory changes lasting for many days leading to functional neurological deficits. Elevations on the order of 3-fold of blood-borne inflammatory MPs, neutrophil activation, glymphatic flow and neuroinflammation in cerebral cortex and hippocampus were found in mice at 12 days after exposure to 760 kPa of air for 2 hours. Mice also exhibited a significant decline in memory and locomotor activity, as assessed by novel object recognition and rotarod testing. Similar inflammatory changes in blood, neuroinflammation and functional impairments were initiated in naïve mice by injection of filamentous (F-) actin-positiveMPs, but not F-actin-negative MPs,obtained from decompressed mice. We conclude that high pressure/decompression stress establishes a systemic inflammatory process that results in prolonged neuroinflammation and functional impairments in the mouse decompression model.

An in vitro model for postoperative cranial nerve dysfunction and a proposed method of rehabilitation with N-acetylcysteine microparticles.

PURPOSE: When operating near cranial motor nerves, transient postoperative weakness of target muscles lasting weeks to months is often observed. As nerves are typically intact at a procedure's completion, paresis is hypothesized to result from a combination of neurapraxia and axonotmesis. As both neurapraxia and axonotmesis involve Schwann cell injury and require remyelination, we developed an in vitro RSC96 Schwann cell model of injury using hydrogen peroxide (H2O2) to induce oxidative stress and investigated the efficacy of candidate therapeutic agents to promote RSC96 viability. As a first step in developing a long-term local administration strategy, the most promising of these agents was incorporated into sustained-release microparticles and investigated for bioactivity using this assay. METHODS: The concentration of H2O2 which reduced viability by 50% was determined to establish a standard for inducing oxidative stress in RSC96 cultures. Fresh cultures were then co-dosed with H2O2 and the potential therapeutics melatonin, N-acetylcysteine, resveratrol, and 4-aminopyridine. Schwann cell viability was evaluated and the most efficacious agent, N-acetylcysteine, was encapsulated into microparticles. Eluted samples of N-acetylcysteine from microparticles was evaluated for retained bioactivity. RESULTS: 100 µM N-acetylcysteine improved the viability of Schwann cells dosed with H2O2. 100 µM Microparticle-eluted N-acetylcysteine also enhanced Schwann cell viability. CONCLUSION: We developed a Schwann cell culture model of iatrogenic nerve injury and used this to identify N-acetylcysteine as an agent to promote recovery. N-acetylcysteine was packaged into microparticles and demonstrated promise as a locally administrable agent to reduce oxidative stress in Schwann cells.

"Invisible" radioactive cesium atoms revealed: Pollucite inclusion in cesium-rich microparticles (CsMPs) from the Fukushima Daiichi Nuclear Power Plant.

Understanding radioactive Cs contamination has been a central issue at Fukushima Daiichi and other nuclear legacy sites; however, atomic-scale characterization of radioactive Cs in environmental samples has never been achieved. Here we report, for the first time, the direct imaging of radioactive Cs atoms using high-resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). In Cs-rich microparticles collected from Japan, we document inclusions that contain 27 - 36 wt% of Cs (reported as Cs2O) in a zeolite: pollucite. The compositions of three pollucite inclusions are (Cs1.86K0.11Rb0.19Ba0.22)2.4(Fe0.85Zn0.84X0.31)2.0Si4.1O12, (Cs1.19K0.05Rb0.19Ba0.22)1.7(Fe0.66Zn0.32X0.41)1.4Si4.6O12, and (Cs1.27K0.21Rb0.29Ba0.15)1.9(Fe0.60Zn0.32X0.69)1.6Si4.4O12 (X includes other cations). HAADF-STEM imaging of pollucite, viewed along the [111] zone axis, revealed an array of Cs atoms, which is consistent with a simulated image using the multi-slice method. The occurrence of pollucite indicates that locally enriched Cs reacted with siliceous substances during the Fukushima meltdowns, presumably through volatilization and condensation. Beta radiation doses from the incorporated Cs are estimated to reach 106 - 107 Gy, which is more than three orders of magnitude less than typical amorphization dose of zeolite. The atomic-resolution imaging of radioactive Cs is an important advance for better understanding the fate of radioactive Cs inside and outside of nuclear reactors damaged by meltdown events.

Poly(malic acid)-budesonide nanoconjugates embedded in microparticles for lung administration.

To improve the therapeutic activity of inhaled glucocorticoids and reduce potential side effects, we designed a formulation combining the advantages of nanoparticles, which have an enhanced uptake by alveolar cells, allow targeted delivery and sustained drug release, as well as limited drug systemic passage, with those of microparticles, which display good alveolar deposition. Herein, a polymer-drug conjugate, poly(malic acid)-budesonide (PMAB), was first synthesized with either 11, 20, 33, or 43 mol% budesonide (drug:polymer from 1:8 to 3:4), the drug creating hydrophobic domains. The obtained conjugates self-assemble into nanoconjugates in water, yielding excellent drug loading of up to 73 wt%, with 80-100 nm diameters. In vitro assays showed that budesonide could be steadily released from the nanoconjugates, and the anti-inflammatory activity was preserved, as evidenced by reduced cytokine production in LPS-activated RAW 264.7 macrophages. Nanoconjugates were then embedded into microparticles through spray-drying with L-leucine, forming nano-embedded microparticles (NEMs). NEMs were produced with an aerodynamic diameter close to 1 µm and a density below 0.1 g.cm-3, indicative of a high alveolar deposition. NEMs spray-dried with the less hydrophobic nanoconjugates, PMAB 1:4, were readily dissolved in simulated lung fluid and were chosen for in vivo experiments to study pharmacokinetics in healthy rats. As it was released in vivo from NEMs, sustained distribution of budesonide was obtained for 48 h in lung tissue, cells, and lining fluid. With high loading rates, modulable release kinetics, and low cytotoxicity, these nanoconjugates delivered by NEMs are promising for the more efficient treatment of pulmonary inflammatory diseases.

Adverse effects of microparticles on transfusion of stored red blood cell concentrates.

BACKGROUND: Systemic and pulmonary coagulopathy and inflammation are important characteristics of transfusion-related acute lung injury (TRALI). Whether microparticles that accumulate in transfused red blood cell concentrates (RBCs) have proinflammatory and procoagulant potential and contribute to adverse reactions of RBC transfusions is unclear. AIM: To investigate the ability of microparticles in stored RBCs to promote thrombin generation and induce human pulmonary microvascular endothelial cell (HMVEC) activation and damage. METHODS: The number and size of microparticles were determined by flow cytometric and nanoparticle tracking analyses, respectively. Thrombin generation and the intrinsic coagulation pathway were assayed by a calibrated automated thrombogram and by measuring activated partial thromboplastin time (aPTT), respectively. The expression of ICAM-1 and the release of cytokines by endothelial cells were detected by flow cytometric analyses. HMVEC damage was assessed by incubating lipopolysaccharide-activated endothelial cells with MP-primed polymorphonuclear neutrophils (PMNs). RESULTS: The size of the microparticles in the RBC supernatant was approximately 100-300 nm. Microparticles promoted thrombin generation in a dose-dependent manner and the aPTT was shortened. Depleting microparticles from the supernatant of RBCs stored for 35 days by either filtration or centrifugation significantly decreased the promotion of thrombin generation. The expression of ICAM-1 on HMVECs was increased significantly by incubation with isolated microparticles. Furthermore, microparticles induced the release of interleukin-6 (IL-6) and interleukin-8 (IL-8) from HMVECs. Microparticles induced lipopolysaccharide-activated HMVEC damage by priming PMNs, but this effect was prevented by inhibiting the PMNs respiratory burst with apocynin. CONCLUSION: Microparticles in stored RBCs promote thrombin generation, HMVEC activation and damage which may be involved in TRALI development.

The potential impact of nano- and microplastics on human health: Understanding human health risks.

Plastics are used all over the world. Unfortunately, due to limited biodegradation, plastics cause a significant level of environmental pollution. The smallest recognized to date are termed nanoplastics (1 nm [nm] up to 1 µm [µm]) and microplastics (1 µm-5 mm). These nano- and microplastics can enter the human body through the respiratory system via inhalation, the digestive tract via consumption of contaminated food and water, or penetration through the skin via cosmetics and clothes contact. Bioaccumulation of plastics in the human body can potentially lead to a range of health issues, including respiratory disorders like lung cancer, asthma and hypersensitivity pneumonitis, neurological symptoms such as fatigue and dizziness, inflammatory bowel disease and even disturbances in gut microbiota. Most studies to date have confirmed that nano- and microplastics can induce apoptosis in cells and have genotoxic and cytotoxic effects. Understanding the cellular and molecular mechanisms of plastics' actions may help extrapolate the risks to humans. The article provides a comprehensive review of articles in databases regarding the impact of nano- and microplastics on human health. The review included retrospective studies and case reports of people exposed to nanoplastics and microplastics. This research highlights the need for further research to fully understand the extent of the impact of plastics on human health.

Recent developments in the fabrication of food microparticles and nanoparticles using microfluidic systems.

Microfluidics is revolutionizing the production of microparticles and nanoparticles, offering precise control over dimensions and internal structure. This technology facilitates the creation of colloidal delivery systems capable of encapsulating and releasing nutraceuticals. Nutraceuticals, often derived from food-grade ingredients, can be used for developing functional foods. This review focuses on the principles and applications of microfluidic systems in crafting colloidal delivery systems for nutraceuticals. It explores the foundational principles behind the development of microfluidic devices for nutraceutical encapsulation and delivery. Additionally, it examines the prospects and challenges with using microfluidics for functional food development. Microfluidic systems can be employed to form emulsions, liposomes, microgels and microspheres, by manipulating minute volumes of fluids flowing within microchannels. This versatility can enhance the dispersibility, stability, and bioavailability of nutraceuticals. However, challenges as scaling up production, fabrication complexity, and microchannel clogging hinder the widespread application of microfluidic technologies. In conclusion, this review highlights the potential role of microfluidics in design and fabrication of nutraceutical delivery systems. At present, this technology is most suitable for exploring the role of specific delivery system features (such as particle size, composition and morphology) on the stability and bioavailability of nutraceuticals, rather than for large-scale production of nutraceutical delivery systems.

Tailored Yolk-Shell Design to Silicon Microparticles via Scalable and Template-Free Synthesis for Superior Lithium Storage.

Micrometer-sized Si particles are beneficial to practical lithium-ion batteries in regard to low cost and high volumetric energy density in comparison with nanostructured Si anodes. However, both the issues of electrical contact loss and overgrowth of solid electrolyte interface for microscale Si induced by colossal volume change still remain to be addressed. Herein, a scalable and template-free method is introduced to fabricate yolk-shell structured Si anode from commercially available Si microparticles. The void is created via a one-step alkali etching process with the remaining silicon core as the yolk, and a double-walled shell is formed from simultaneous in situ growth of the conformal native oxide layer and subsequent carbon coating. In this configuration, the well-defined void spaces allow the Si core to expand without compromising structural integrity, while the double-walled shell acts as a static capsule to confine silicon fragments despite likely particle fracture. Therefore, electrical connectivity is maintained on both the particle and electrode level during deep galvanostatic cycling, and the solid-electrolyte interface is stabilized on the shell surface. Owing to the benefits of tailored design, excellent cycling stability (capacity retention of 95% after 100 cycles) and high coulombic efficiency (99.5%) are realized in a practical full-cell demonstration.

Structural Stabilization of Clinically Oriented Oligomeric Proteins During their Transit through Synthetic Secretory Amyloids.

Developing time-sustained drug delivery systems is a main goal in innovative medicines. Inspired by the architecture of secretory granules from the mammalian endocrine system it has generated non-toxic microscale amyloid materials through the coordination between divalent metals and poly-histidine stretches. Like their natural counterparts that keep the functionalities of the assembled protein, those synthetic structures release biologically active proteins during a slow self-disintegration process occurring in vitro and upon in vivo administration. Being these granules formed by a single pure protein species and therefore, chemically homogenous, they act as highly promising time-sustained drug delivery systems. Despite their enormous clinical potential, the nature of the clustering process and the quality of the released protein have been so far neglected issues. By using diverse polypeptide species and their protein-only oligomeric nanoscale versions as convenient models, a conformational rearrangement and a stabilization of the building blocks during their transit through the secretory granules, being the released material structurally distinguishable from the original source is proved here. This fact indicates a dynamic nature of secretory amyloids that act as conformational arrangers rather than as plain, inert protein-recruiting/protein-releasing granular depots.

Poly(D,l-lactide-co-glycolide) particles are metabolised by the gut microbiome and elevate short chain fatty acids.

The production of short chain fatty acids (SCFAs) by the colonic microbiome has numerous benefits for human health, including maintenance of epithelial barrier function, suppression of colitis, and protection against carcinogenesis. Despite the therapeutic potential, there is currently no optimal approach for elevating the colonic microbiome's synthesis of SCFAs. In this study, poly(D,l-lactide-co-glycolide) (PLGA) was investigated for this application, as it was hypothesised that the colonic microbiota would metabolise PLGA to its lactate monomers, which would promote the resident microbiota's synthesis of SCFAs. Two grades of spray dried PLGA, alongside a lactate bolus control, were screened in an advanced model of the human colon, known as the M-SHIME® system. Whilst the high molecular weight (Mw) grade of PLGA was stable in the presence of the microbiota sourced from three healthy humans, the low Mw PLGA (PLGA 2) was found to be metabolised. This microbial degradation led to sustained release of lactate over 48 h and increased concentrations of the SCFAs propionate and butyrate. Further, microbial synthesis of harmful ammonium was significantly reduced compared to untreated controls. Interestingly, both types of PLGA were found to influence the composition of the luminal and mucosal microbiota in a donor-specific manner. An in vitro model of an inflamed colonic epithelium also showed the polymer to affect the expression of pro- and anti-inflammatory markers, such as interleukins 8 and 10. The findings of this study reveal PLGA's sensitivity to enzymatic metabolism in the gut, which could be harnessed for therapeutic elevation of colonic SCFAs.

Hierarchical Polyimide Microparticles with Controllable Morphology.

Hierarchical polyimides (PIs) not only show outstanding thermal stability and high mechanical strength but also have great advantages in terms of microstructure and surface area, which makes them highly valuable in various fields such as aerospace, microelectronics, adsorption, catalysis, and energy storage. However, great challenges still remain in the synthesis of hierarchical PIs with well-defined microstructure. Herein, polyamide acid salts (PAAS) with tunable ionization degree are synthesized first via the polymerization of dianhydride and diamine monomers in deionized water with 1,2-dimethylimidazole (DMIZ). Then cationic cetyltrimethylammonium chloride (CTAC) is added to the PAAS aqueous solution to induce the formation of polyelectrolyte-surfactant complexes based on electrostatic interaction. After a typical hydrothermal reaction (HTR) procedure, hierarchical PIs with different microstructures such as urchin-like PI microparticles, flower-like PI microparticles, and lamellar PI petals can be fabricated simply by changing the additive amount of DMIZ and CTAC. The nanostructure self-assemblies of PAAS are dominated by the charges on macromolecular chains and the formation of hierarchical structures of polymers is ascribed to a geometrical selection process during crystal growth. This work provides valuable insights into the self-assembly behaviors of polyelectrolyte systems for synthesizing well-defined hierarchical polymers.

Switching Separation Migration Order by Switching Electrokinetic Regime in Electrokinetic Microsystems.

Analyte migration order is a major aspect in all migration-based analytical separations methods. Presented here is the manipulation of the migration order of microparticles in an insulator-based electrokinetic separation. Three distinct particle mixtures were studied: a binary mixture of particles with similar electrical charge and different sizes, and two tertiary mixtures of particles of distinct sizes. Each one of the particle mixtures was separated twice, the first separation was performed under low voltage (linear electrokinetic regime) and the second separation was performed under high voltage (nonlinear electrokinetic regime). Linear electrophoresis, which discriminates particles by charge, is the dominant electrokinetic effect in the linear regime; while nonlinear electrophoresis, which discriminates particles by size and shape, is the dominant electrokinetic effect in the nonlinear regime. The separation results obtained with the three particle mixtures illustrated that particle elution order can be changed by switching from the linear electrokinetic regime to the nonlinear electrokinetic regime. Also, in all cases, better separation performances in terms of separation resolution (Rs) were obtained by employing the nonlinear electrokinetic regime allowing nonlinear electrophoresis to be the discriminatory electrokinetic mechanism. These findings could be applied to analyze complex samples containing bioparticles of interest within the micron size range. This is the first report where particle elution order is altered in an iEK system.

Silica Microparticles from Sugarcane By-Products as an Encapsulation System for Retinoids Aimed at Topical Sustained Release.

The encapsulation of retinol within silica microparticles has emerged as a promising opportunity in the realm of cosmetic and pharmaceutical formulations, driven by the need to reinforce the photoprotection and oxidation stability of retinol. This work examines the process of encapsulating retinol into silica microparticles. The association efficiency, microparticle size, molecular structure, morphology, oxidation, and release profile, as well as biocompatibility and skin sensitization, were evaluated. Results showed that 0.03% of retinol and 9% of emulsifier leads to an association efficiency higher than 99% and a particle size with an average of 5.2 µm. FTIR results indicate that there is an association of retinol with the silica microparticles, and some may be on the surface. Microscopy indicates that when association happens, there is less aggregation of the particles. Oxidation occurs in two different phases, the first related to the retinol on the surface and the second to the associated retinol. In addition, a burst release of up to 3 h (30% free retinol, 17% associated retinol) was observed, as well as a sustained release of 44% of retinol up to 24 h. Encapsulation allowed an increase in the minimal skin cytotoxic concentrations of retinol from 0.04 µg/mL to 1.25 mg/mL without skin sensitization. Overall, retinol is protected when associated with silica microparticles, being safe to use in cosmetics and dermatology.

Improved hydration property of tissue adhesive/hemostatic microparticle based on hydrophobically-modified Alaska pollock gelatin.

The management of bleeding is an important aspect of endoscopic surgery to avoid excessive blood loss and minimize pain. In clinical settings, sprayable hemostatic particles are used for their easy delivery, adaptability to irregular shapes, and rapid hydration. However, conventional hemostatic particles present challenges associated with tissue adhesion. In a previous study, we reported tissue adhesive microparticles (C10-sa-MPs) derived from Alaska pollock gelatin modified with decyl groups (C10-sa-ApGltn) using secondary amines as linkages. The C10-sa-MPs adhere to soft tissues through a hydration mechanism. However, their application as a hemostatic agent was limited by their long hydration times, attributed to their high hydrophobicity. In this study, we present a new type microparticle, C10-am-MPs, synthesized by incorporating decanoyl group modifications into ApGltn (C10-am-ApGltn), using amide bonds as linkages. C10-am-MPs exhibited enhanced hydration characteristics compared to C10-sa-MPs, attributed to superior water absorption facilitated by amide bonds rather than secondary amines. Furthermore, C10-am-MPs demonstrated comparable tissue adhesion properties and underwater adhesion stability to C10-sa-MPs. Notably, C10-am-MPs exhibited accelerated blood coagulation in vitro compared to C10-sa-MPs. The application of C10-am-MPs in an in vivo rat liver hemorrhage model resulted in a hemostatic effect comparable to a commercially available hemostatic particle. These findings highlight the potential utility of C10-am-MPs as an effective hemostatic agent for endoscopic procedures and surgical interventions.