Release Of Microparticles Research Articles

Novel formulations in the treatment of glaucoma

AbstractNeuroprotective therapy in glaucoma is gaining a lot of interest to be used alone or simultaneously with the control of intraocular pressure (IOP). Neuronal degeneration process occurs through different pathways. For this reason, effective neuroprotection of retinal ganglion cells (RGC) and other retinal cells in glaucoma must be performed according to different targets. Recently, there is special interest in designing treatments able to include a combination of active agents in the same formulation.Treatments destined to lower IOP, in which the target is the anterior segment of the eye are administered topically. By the contrary, neuroprotective therapies require the administration of the active substances close to the retinal tissues as well as their maintenance during long term. Since the last decades the development of intraocular drug delivery systems (IDDS) has emerged as therapeutic tools to provide therapeutic concentrations inside the eye during long term, thus reducing the number of injections. Among the controlled release devices, implants (>1 mm) and microparticles (1–1000 μm), are capable of releasing the active substance during long time. Furthermore, if they are prepared with biodegradable polymers, they have the advantage of disappearing from the site of administration after releasing the drug. There are currently two biodegradable implants in the clinical practice to avoid frequent administrations. One of them is loaded with dexamethasone (Ozurdex®) for intravitreal injection and Durysta™ administered in the anterior chamber. Both devices are prepared from the biopolymers derived from the lactic and glycolic acid poly‐(lactic‐co‐glycolic) acid, named as PLGA. The final products of this biodegradable biomaterial result well tolerated and they are finally eliminated from the body.Despite the advantages of the commercialized biodegradable implants, they did not allow personalized therapy and microparticles (mainly PLGA microspheres) are under investigation as therapeutic platforms for intraocular purposes(1). One of their main advantages is that they can be administered as a suspension in the vitreous using small gauge needles (30‐32G). Another interesting advantage of microspheres is that, by being able to easily modify the amount of microparticles to be administered, they become very useful tools for personalized therapies.Microspheres allow to incorporate several drugs in the same device providing a simultaneous delivery of the active substances, resulting of special interest in multifactorial diseases(2). Furthermore, the amount of injected polymer in the co‐loaded device resulted lower compared to single‐loaded systems.Acknowledgements‐Grant: PID2020‐113281RB‐C21 funded by MCIN/AEI/ 10.13039/501100011033, Research Group UCM 920415 “Innovation, Therapy and Pharmaceutical Development in Ophthalmology (InnOftal)” and the ISCII‐FEDER RETICS (OFTARED) (RD16/0008/0004 and RD16/0008/0009).

Giving green grass jelly for mda (malondialdehyde) level in pregnant women with hypertension

<p align="center"><strong><em> </em></strong></p><p><strong><em>Background:</em></strong><em> Hypertension is a disease that often occurs during pregnancy. Many factors influence the occurrence of hypertension, one of which is oxidative stress. Oxidative stress has an important role in the pathogenesis of hypertension in pregnancy and may be a pathway that can lead to tissue damage. Oxidative stress can stimulate the release of cytokines, antiangiogenic, microparticles and other important molecules in hypertension. Oxidative stress is caused by an imbalance of prooxidants and antioxidants. So we need antioxidants that can suppress oxidative stress in pregnant women with hypertension. Green grass jelly contains alkaloids and flavonoids. Where flavonoids can act as antioxidants and anti-inflammatory. Flavonoids can reduce arterial stiffness making Reactive Oxygen Species (ROS) decrease so that fat peroxide decreases and is followed by decreased oxidative stress, then endothelial function will increase and vasodilation occurs. Malondialdehyde (MDA) is an aldehyde marker compound that is important to see lipid peroxidation and oxidative damage caused by Reactive Oxygen Species (ROS).</em></p><p><strong><em>Objectives:</em></strong><em> To prove that giving green grass jelly has an effect on reducing oxidative stress in pregnant women.</em></p><p><strong><em>Methods</em></strong><em>: This study used a quasy experiment with a pretest and posttest control design. A sample of 30 was divided into 2 groups. The group with green grass jelly intervention was 15 people who were given green grass jelly as much as 150 grams per day for 14 days. The second group as many as 15 people as the control group.</em></p><p><strong><em>Results:</em></strong><em> The green grass jelly intervention group had a significant difference with p-value <0.05. For malondialdehyde results in the control group there was no change in p-value > 0.05. The mean decrease in malondialdehyde levels in the control group was 0.0560 nmol/ml while the average decrease in malondialdehyde in the intervention group was 1.3133 nmol/ml.</em></p><strong><em>Conclusions:</em></strong><em> Green grass jelly is effective and significant for reducing malondialdehyde levels in pregnant women with mild hypertension.</em>

Bioadhesive Perivascular Microparticle-Gel Drug Delivery System for Intimal Hyperplasia Prevention: In Vitro Evaluation and Preliminary Biocompatibility Assessment.

Intimal hyperplasia (IH) is an undesirable pathology occurring after peripheral or coronary bypass surgery. It involves the proliferation and migration of vascular smooth muscle cells, leading to a reduction in the diameter of the vascular lumen, which can lead to stenosis and graft failure. Topically applied atorvastatin (ATV) has been shown to slow down this process. To be effective, the drug delivery system should remain at the perivascular site for 5-8 weeks, corresponding to the progression of IH, and be capable of releasing an initial dose of the drug followed by a sustained release. Ideally, bioadhesion would anchor the gel to the application site. To meet these needs, we encapsulated ATV in a 2-component system: a hyaluronic acid-dopamine bioadhesive gel for rapid release and biodegradable microparticles for sustained release. The system was characterized by scanning electron microscopy, rheology, bioadhesion on porcine arteries, and a release profile. The rheological properties were adequate for perivascular application, and we demonstrated superior bioadhesion and cohesion compared to the control HA formulations. The release profile showed a burst, generated by free ATV, followed by sustained release over 8 weeks. A preliminary evaluation of subcutaneous biocompatibility in rats showed good tolerance of the gel. These results offer new perspectives on the perivascular application towards an effective solution for the prevention of IH.

Pathophysiological mechanisms of thrombosis in acute and long COVID-19.

COVID-19 patients have a high incidence of thrombosis, and thromboembolic complications are associated with severe COVID-19 and high mortality. COVID-19 disease is associated with a hyper-inflammatory response (cytokine storm) mediated by the immune system. However, the role of the inflammatory response in thrombosis remains incompletely understood. In this review, we investigate the crosstalk between inflammation and thrombosis in the context of COVID-19, focusing on the contributions of inflammation to the pathogenesis of thrombosis, and propose combined use of anti-inflammatory and anticoagulant therapeutics. Under inflammatory conditions, the interactions between neutrophils and platelets, platelet activation, monocyte tissue factor expression, microparticle release, and phosphatidylserine (PS) externalization as well as complement activation are collectively involved in immune-thrombosis. Inflammation results in the activation and apoptosis of blood cells, leading to microparticle release and PS externalization on blood cells and microparticles, which significantly enhances the catalytic efficiency of the tenase and prothrombinase complexes, and promotes thrombin-mediated fibrin generation and local blood clot formation. Given the risk of thrombosis in the COVID-19, the importance of antithrombotic therapies has been generally recognized, but certain deficiencies and treatment gaps in remain. Antiplatelet drugs are not in combination with anticoagulant treatments, thus fail to dampen platelet procoagulant activity. Current treatments also do not propose an optimal time for anticoagulation. The efficacy of anticoagulant treatments depends on the time of therapy initiation. The best time for antithrombotic therapy is as early as possible after diagnosis, ideally in the early stage of the disease. We also elaborate on the possible mechanisms of long COVID thromboembolic complications, including persistent inflammation, endothelial injury and dysfunction, and coagulation abnormalities. The above-mentioned contents provide therapeutic strategies for COVID-19 patients and further improve patient outcomes.

Membrane Bending Enhances Sulfatide Mediated Sickle Mature Erythrocyte Adhesion

Introduction: Abnormal red blood cell (RBC) adhesion due to polymerization of sickle hemoglobin (HbS) is central to the pathophysiology of SCD. Early erythrocytes (reticulocytes), expanded in number due to sustained stress erythropoiesis stimulated by anemia and hypoxia, are more adhesive to vascular endothelial proteins and surfaces than are mature erythrocytes. However, mature erythrocytes typically constitute >80% of all RBCs in SCD, and the relative contribution made by erythrocytes vs. reticulocytes to acute and chronic vasculopathy is not well understood. We hypothesized that sphingomyelinase (SMase) activity that is upregulated by accumulated bending energy leads to elevated membrane sulfatide availability and thus hypoxic mature erythrocyte adhesion under hypoxia. Methods: We probed the adhesion of RBCs obtained from SCD patients (#NCT02824471) stained with acridine orange under various physiological conditions in microchannels that were coated with laminin. Then we analyzed the morphology of single sickle reticulocytes and mature erythrocytes to estimate the membrane bending energy. Results and Discussion: We found that mature erythrocyte adhesion to laminin in controlled microfluidic experiments is significantly greater under hypoxia than under normoxia (1856±481 vs. 78±23, mean±SEM), while sickle reticulocyte adhesion, high to begin with, does not change (1281 ±299 vs. 1258±328, mean±SEM). Furthermore, we show that among the adherent RBCs, mature erythrocytes have greater elongation and accumulated membrane bending energy compared to reticulocytes under hypoxia (Figure 1A). Accumulated membrane bending is known to elicit SMase, and laminin establishes highly specific bonds with sulfatides which are downstream of the SMase. These results suggest that SMase is likely elicited particularly in sickle mature erythrocytes, which become highly adhesive with deoxygenation. This is likely due to loss of membrane surface area with RBC maturation, which may be excessive in SCD due to membrane vesiculation and microparticle release. To elucidate the roles of SMase and sulfatide in the adhesion of mature erythrocytes, we repeated the adhesion experiments with SMase and anti-sulfatide incubation. We found that SMase increases the hypoxia-enhanced adhesion of mature erythrocytes and the anti-sulfatide antibody inhibits the enhanced adhesion of mature erythrocytes seen under hypoxia (Figure 1B). Collectively, these data demonstrate the effect of accumulated membrane damage on the abnormal adhesion of sickle mature erythrocytes. Conclusions: Patient-to-patient variability in hypoxia enhanced mature erythrocyte adhesion suggests a role in modulating clinical comorbidities and or genetic polymorphisms relevant to red cell health and hypoxic regulation. These results also implicate the lipid components of the plasma membrane in the pathophysiology of RBC dysfunction in SCD. Therefore, sulfatide and the components of its pathway, such as SMase, could be explored as potential therapeutic targets to inhibit sickle erythrocyte adhesion in SCD. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Autoimmune Hemolytic Anemia and Increased Stroke Risk in the United States: A Population-Based Study

Introduction Autoimmune hemolytic anemia (AIHA) is a clinically heterogeneous collection of disorders characterized by the presence of autoantibodies against the patient's erythrocytes. AHIA has been associated with an increased risk of thromboembolic events, including stroke. A recent nationwide cohort study from Denmark and France showed an increased risk of ischemic stroke compared to the general population. However, no extensive studies have been done in the United States (US); hence, we conducted a study of stroke and AIHA in the US population. Methods This is a retrospective study from 1999 to 2022. We analyzed data from a nationwide commercial database (Explorys, IBM) that aggregates records from 26 healthcare systems spread over 50 states with almost 80 million patients. It is a cloud-based platform in which participating institutions provide de-identified data from electronic health records. Pooled data is then standardized and normalized. Explorys uses Systemized Nomenclature of Medicine - Clinical Terms (SNOMED CT) coding for medical diagnosis. We identified adult patients (over 18 years old) with the diagnosis of AIHA. Patients with stroke were identified with the following SNOMED-CT diagnosis "cerebrovascular accidents''. In addition, we obtained information on risk factors for stroke, including sex, age over 65 years, and comorbidities known to be a risk factor, including hypertension, atrial fibrillation, diabetes mellitus, hyperlipidemia, smoking, and obesity.Multivariable logistic regression adjusting for all covariates was created to test for stroke. Results were presented as odds ratio (OR) with a corresponding 95% confidence interval (CI). All tests were two-sided, and a p-value ≤ 0.01 was considered statistically significant. Results An adult population of 69,339,860 were included. AHIA was diagnosed in 12,800 patients (less than 1 per 100,000) and stroke was diagnosed in 238,860 (0.34%). AIHA population characteristics were; females 7,720 (60%), age over 65 years 7,510 (59%), stroke 260 (2%), hypertension 8,260 (65%), hyperlipidemia 6,580 (51%), diabetes mellitus 4,030 (31%), obesity 3,080 (24%), atrial fibrillation 2,650 (21%), and smoking 1,080 (14%). Baseline characteristics are shown in table 1. Statically significant OR of covariates tested is as follows; hypertension OR 9.35 (95% CI 9.22-9.49), AHIA OR 2.75 (95% CI 2.49 - 3.01), atrial fibrillation OR 2.59 (95% CI 2.57 - 2.62), diabetes mellitus 2.44 (95% CI 2.42, 2.47), hyperlipidemia OR 1.96 (95% CI 1.94, 1.98), smoking OR 1.5 (95% CI 1.94, 1.98), age over 65 years OR 1.19 (95% CI 1.18, 1.20), and male OR 0.85 (95% CI 0.84, 0.85). Multivariable logistic regression of factors associated with stroke is shown in table 2. Discussion and conclusion This is the largest population-based study analyzing the association between AIHA and stroke, and we included the most relevant confounding risk factors in our analysis. As expected, the strongest risk factor associated with stroke was hypertension. What was surprising was that AIHA followed it as the second strongest risk factor, which exceeded atrial fibrillation as a risk factor. Limitations of the retrospective design of the study are numerous. They include lack of patient-level data, the subtype of stroke, the subtype of AIHA, the severity of AIHA, temporality, medications used, and their implications on stroke risk, and inaccuracies in coding. A potential explanation for increased thrombosis includes depletion of nitric oxide as a consequence of intravascular hemolysis with resultant enhanced platelet adhesions, and another possible mechanism is the release of procoagulant microparticles during hemolysis. While there is an ongoing trial looking into long-term apixaban in the primary prevention of venous thromboembolism in AIHA (NCT05089227), no active study is looking into minimizing stroke risk. Prospective studies to affirm association, risk stratifies patients, and ultimately test the utility of prophylactic anticoagulation are most needed. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Recombinant protein diannexin prevents preeclampsia-like symptoms in a pregnant mouse model via reducing the release of microparticles.

Preeclampsia (PE) is characterized by placenta-mediated pregnancy complication. The only effective treatment for PE is the delivery of the placenta. However, this treatment may cause preterm birth and neonatal death. Therefore, preventing PE is needed. The mechanism of PE involves abnormal placentation, which leads to the release of anti-angiogenic and inflammatory mediators into maternal circulation. These mediators contribute to systemic vascular dysfunction, inflammatory responses, and excessive thrombin generation. Microparticles (MPs) are reportedly involved in PE by promoting the thromboinflammatory response. This study describes a strategy to prevent PE by reducing MP release using the recombinant protein, diannexin. Results showed that the patients with PE had elevated MP number and procoagulant activity and increased NLRP3 inflammasome activation. Additionally, diannexin remarkably reduced the release of MPs from activated cells by binding to phosphatidylserine exposed on the surface of activated cells. Moreover, in vivo results showed that diannexin could prevent PE-like symptoms by decreasing MPs and NLRP3 inflammasome activation in pregnant mice. Furthermore, diannexin effectively inhibited trophoblast cell activation and NLRP3 inflammasome activation in vitro. These findings suggested that diannexin inhibited MP release and might be an effective therapeutic strategy for preventing PE.

A comparative study of PLGA microparticle properties loaded with micronized, nanosized or dissolved drug

The objective of this study was to compare properties of poly(lactide-co-glycolide) (PLGA) microparticles loaded with dexamethasone or hydrocortisone in the micronized, nanosized or dissolved state. Dexamethasone and hydrocortisone were nanosized by wet bead milling. The microparticles were prepared by a solvent extraction/evaporation method and were characterized by particle size, encapsulation efficiency, drug solid-state, morphology, in vitro release and dynamic microparticle diameter changes during release. The micronized and nanosized drugs were still in crystalline form after encapsulation into PLGA microparticles with encapsulation efficiencies greater than 85 %. Encapsulating dissolved drugs resulted in lower encapsulation efficiencies (32 to 63 %) and the dissolved drug recrystallized within the PLGA matrix at a higher actual drug loading of 30 %. The order in drug release depended on the physical state of the encapsulated drug and was in the order of dissolved > nanosized > micronized drug. Interestingly, quasi-linear release profiles were obtained with 10 % nanosized dexamethasone in PLGA 502H and 503H microparticles. In conclusion, encapsulating dispersed and, in particular, nanosized drug into PLGA microparticles is a promising tool to increase the encapsulation efficiency, to maintain a stable drug solid-state and to achieve a more continuous release profile.

Platelet-Derived Extracellular Vesicles Stimulate Migration through Partial Remodelling of the Ca2+ Handling Machinery in MDA-MB-231 Breast Cancer Cells.

Background: Platelets can support cancer progression via the release of microparticles and microvesicles that enhance the migratory behaviour of recipient cancer cells. We recently showed that platelet-derived extracellular vesicles (PEVs) stimulate migration and invasiveness in highly metastatic MDA-MB-231 cells by stimulating the phosphorylation of p38 MAPK and the myosin light chain 2 (MLC2). Herein, we assessed whether the pro-migratory effect of PEVs involves the remodelling of the Ca2+ handling machinery, which drives MDA-MB-231 cell motility. Methods: PEVs were isolated from human blood platelets, and Fura-2/AM Ca2+ imaging, RT-qPCR, and immunoblotting were exploited to assess their effect on intracellular Ca2+ dynamics and Ca2+-dependent migratory processes in MDA-MB-231 cells. Results: Pretreating MDA-MB-231 cells with PEVs for 24 h caused an increase in Ca2+ release from the endoplasmic reticulum (ER) due to the up-regulation of SERCA2B and InsP3R1/InsP3R2 mRNAs and proteins. The consequent enhancement of ER Ca2+ depletion led to a significant increase in store-operated Ca2+ entry. The larger Ca2+ mobilization from the ER was required to potentiate serum-induced migration by recruiting p38 MAPK and MLC2. Conclusions: PEVs stimulate migration in the highly metastatic MDA-MB-231 breast cancer cell line by inducing a partial remodelling of the Ca2+ handling machinery.

Revealing the role of supernatant and granular sludge fractions on granular anaerobic membrane bioreactor fouling

In order to design efficient fouling mitigation strategies in granular anaerobic membrane bioreactors (G-AnMBR), foulant characteristics and their role have to be thoroughly investigated. Raw mixed liquor of G-AnMBR was split by sieving into granules and supernatant fractions at 0.125 mm. Then, the fouling potential and reversibility of the different samples (granules, supernatant and raw mixed liquor) were assessed by measuring critical fluxes and through filtration tests. Various hydrodynamic conditions, i.e. gas sparging and recirculation, were applied to evaluate the impact of shear stress on fouling propensity. Results revealed that the supernatant fraction, composed of fine compounds and micro-particles, had a strong fouling potential, whilst the granule fraction led to minor fouling filtration resistance. Three-dimensional excitation emission fluorescence spectroscopy emphasised the prominent role of colloidal proteins in G-AnMBR membrane fouling. During the filtration test of raw mixed liquor, the fouling propensity of the micro-particles was lowered, since the structural cake layer was modified. Gas sparging allowed for the mitigation of cake formation, but excess of shear forces may lead to granule break-up and more irreversible fouling. Liquid recirculation led to a higher filtration resistance, but almost all the membrane permeability was recovered by physical cleaning. A short filtration cycle without gas sparging followed by a short period of relaxation and gas sparging could be a suitable fouling mitigation method. In this way, release of micro-particles from granule break-up could be limited, the cake build-up would be mostly reversible by physical cleaning, and the energy demand of gas sparging would be greatly reduced, thereby improving the energy neutrality of the G-AnMBR biotechnology.

Nimbolide loaded sustained release microparticles as single-dose formulations for effective management of arthritis

At present, sustained-release formulations have gained immense interest in drug development for improving the pharmacokinetic and pharmacodynamic properties of drugs. Nimbolide (NMB), one of the active constituents of the Neem tree (Azadirachta indica), has been studied for its anti-carcinogenic, anti-fibrotic, and anti-inflammatory properties, but it has poor pharmacokinetic issues. This study aims for preparing an intra-articularly injectable NMB-PLGA microparticle formulation (NMB MPs) that releases NMB in a sustained fashion once localized in joints for the treatment of arthritis. The formulation was characterized by scanning electron microscope, infrared spectroscopy, and in vitro drug release profiles. The MPs were spherical as evidenced by microscopic images with a mean diameter of 9.17 ± 2.75 μm. With the drug loading of 28% of NMB, the entrapment efficiency was 71.22 ± 3.53%. The formulated MPs could extend the drug release up to 62.25 ± 6.58%in 33 days in the in vitro conditions. The in vivo therapeutic effect of NMB MPs (single dose) was investigated in comparison to NMB free drug (weekly doses) in the rat model of Complete Freund's Adjuvant (CFA) induced arthritis. The anti-arthritic activity was evaluated based on knee swelling, X-ray analysis of knee joints, histopathology scoring, and expression of various essential proteins. The observed superior protective effects can be attributed to the sustained release of NMB from NMB MPs that facilitated the maintenance of therapeutic drug levels. In conclusion, NMB MPs can be a useful injectable delivery system for enhancing therapeutic efficiency in treating joint diseases.

The Effect of Hormonal Treatment on Selected Sperm Quality Parameters and Sex Steroids in Tropical Cyprinid Bala Shark Balantiocheilos melanopterus

Hormone treatments are routinely employed with bala shark Balantiocheilos melanopterus male broodstock to stimulate the production of high-quality sperm. In the current trial, three spermiation-inducing treatments were evaluated: 20 μg/kg body weight (BW) recombinant hCG; 20 μg/kg BW [D-Ala6, Pro9, NEt]- gonadotropin-releasing hormone (GnRHa) with 20 mg/kg BW metoclopramide; and poly(lactic-co-glycolic acid) (PLGA) microparticles with slow release of 10 μg/kg BW GnRHa. A 0.9% saline AS negative control was also included. Administration of the GnRHa through the form of slow release of PLGA microparticles 24 h after treatment resulted in a significantly higher sperm volume, motility percentage, and total sperm count compared to the control. Injection of GnRHa with metoclopramide induced sperm parameters that did not differ from the control, with the exception of motility percentage. The lowest potency to induce spermiation in bala sharks was in the treatment with recombinant hCG. Both PLGA microparticles and GnRHa with metoclopramide significantly increased blood plasma concentrations of testosterone and 11-ketotestosterone compared to the control. The PLGA microparticle system with continuous release of 10 μg/kg BW GnRHa was the most effective treatment in inducing spermiation in bala sharks.

Incidence of Venous Thromboembolism in Multiple Myeloma Patients across Different Regimens: Role of Procoagulant Microparticles and Cytokine Release.

Introduction: Multiple myeloma (MM) is characterized by a high prevalence of thrombotic complications. Microvesicles (MVs) are small membrane vesicles released from activated cells, and they may potentially contribute to thrombosis. Methods: We have evaluated the plasma levels of MVs and cytokines (IL-10, IL-17, and TGF-β in MM and Watch and Wait Smoldering MM (WWSMM) from patients and related them to thrombotic complications. The secondary aim was to assess the impact of ongoing therapy on MV and on cytokine levels. Result: 92 MM and 31 WWSMM were enrolled, and 14 (12%) experienced a thrombotic episode. Using univariate analysis, TGF-β and MV were significantly higher in patients with thrombotic events (p = 0.012; p = 0.008, respectively). Utilizing a Cox proportional hazard model, we confirmed this difference (TGF-β p = 0.003; Odds ratio 0.001, 95% CI 0–0.003 and MV p = 0.001; Odds ratio 0.003, 95% CI 0.001–0.005). Active treatment management displayed higher levels of MV (p < 0.001) and lower levels of glomerular filtration-rate (p < 0.001), IL-17 (p < 0.001) as compared to the WWSMM group. The TGF-β values of immunomodulatory derivatives patients were lower in the WWSMM (p < 0.001) and Dexamethasone/Bortezomib subgroup (p < 0.001). Conclusion: The increased levels of MVs in active regimens add insight into the mechanisms of hypercoagulation in MM. In addition, a role for cytokine-related thrombosis is also suggested.

TMEM16F mediated phosphatidylserine exposure and microparticle release on erythrocyte contribute to hypercoagulable state in hyperuricemia

The link between hyperuricemia (HUA) and the risk of venous thromboembolism (VTE) has been well established. However, the mechanisms of thrombus generation and the effect of HUA on procoagulant activity (PCA) of erythrocytes remain unclear no matter in uremia or hyperuricemia. Here, phosphatidylserine (PS) exposure, microparticles (MPs) release, cytosolic Ca2+, TMEM16F expression, reactive oxygen species (ROS) and lipid peroxidation of erythrocyte were detected by flow cytometer. PCA was assessed by coagulation time, purified coagulation complex and fibrin production assays. The fibrin formation was observed by scanning electron microscopy (SEM). We found that PS exposure, MPs generation, TMEM16F expression and consequent PCA of erythrocyte in HUA patients significantly increased compared to those in healthy volunteers. Furthermore, high UA induced PS exposure, and MPs release of erythrocyte in concentration and time-dependent manners in vitro, which enhanced the PCA of erythrocyte and was inhibited by lactadherin, a PS inhibitor. Additionally, using SEM, we also observed compact fibrin clots with highly-branched networks and thin fibers supported by red blood cells (RBCs) and RBC-derived MPs (RMPs). Importantly, we demonstrated UA enhanced the production of ROS and lipid peroxidation and reduced the generation of glutathione (GSH) of erythrocyte, which enhanced TMEM16F activity and followed PS externalization and RMPs formation. Collectively, these results suggest that Ca2+-dependent TMEM16F activation may be responsible for UA-induced PS exposure and MPs release of RBC, which thereby contribute to the prothrombotic risk in HUA.

Physicochemical change and microparticle release from disposable gloves in the aqueous environment impacted by accelerated weathering

The explosive growth of disposable gloves usage in cities around the world has posed a considerable risk to municipal solid management and disposal during the COVID-19 pandemic. The lack of the environmental awareness leads to glove waste being discarded randomly and ending up in the soil and/or the ocean ecosystem. To explore the physicochemical changes and environmental behaviors of disposable glove wastes in the aqueous environment, three kinds of glove (latex, nitrile and vinyl) were investigated. The results showed that the physicochemical characteristics of disposable gloves made of different materials were altered to different degrees by UV weathering. Nitrile gloves were more stable than latex and vinyl gloves after being exposed to weathering conditions. Although the chemical structures were not clearly demonstrated through FTIR after weathering, the SEM results showed significant microscopic changes on the surfaces of the gloves. Analysis of the leachate results showed that UV weathered gloves released leachable substances, including microparticles, organic matter, and heavy metals. Latex gloves were more likely to release microparticles and other substances into the water after UV weathering. The release of microparticles from gloves can also be impacted by sand abrasion. The appropriate strategy needs to be developed to mitigate the environmental impact caused by the discarded gloves.

Effect of lower‐leg trauma and knee arthroscopy on procoagulant phospholipid‐dependent activity

BackgroundLower‐leg injury and knee arthroscopy are both associated with venous thromboembolism (VTE). The mechanism of VTE in both situations is unknown, including the role of procoagulant microparticles. This may provide useful information for individualizing thromboprophylactic treatment in both patient groups. ObjectiveWe aimed to study the effect of (1) lower‐leg trauma and (2) knee arthroscopy on procoagulant phospholipid‐dependent (PPL) activity plasma levels. MethodsPOT‐(K)CAST trial participants who did not develop VTE were randomly selected for the current study. Plasma was collected shortly after lower‐leg trauma or before and after knee arthroscopy. For aim 1, samples of 67 patients with lower‐leg injury were compared with control samples (preoperative samples of 74 patients undergoing arthroscopy). Linear regression was used to obtain mean ratios (natural logarithm retransformed data), adjusted for age, sex, body mass index, infections, and comorbidities. For aim 2, pre‐ and postoperative samples of 49 patients undergoing arthroscopy were compared using paired t tests. PPL activity was measured using modified activated factor X–dependent PPL clotting assay. ResultsFor aim 1, PPL activity levels were almost threefold higher in patients with lower‐leg injury compared with controls, that is, mean ratio, 2.82 (95% confidence interval [CI], 1.98‐4.03). For aim 2, postoperative PPL activity levels did not change significantly, that is, mean change, −0.72 mU/mL (95% CI, −2.03 to 0.59). ConclusionLower‐leg trauma was associated with increased plasma levels of PPL activity, in contrast to knee arthroscopy. Lower‐leg trauma triggers the release of procoagulant microparticles.

Clustering Transition in Thermo‐Responsive Micropillars

Clustering of high‐aspect‐ratio micropillars is a common phenomenon in nature, and has been utilized to build complex and large‐scale microarchitectures. To induce the clustering, the micropillars should be prepared to be metastable, so that they cluster under perturbation, such as the drying of water. Consequently, once micropillars cluster, they cannot de‐cluster spontaneously. This article shows that the micropillars of thermo‐responsive hydrogels can cluster and de‐cluster spontaneously and reversibly by changing the temperature. This behavior is called clustering transition. When the temperature is low, the micropillars swell and become soft. When the temperature is high, the micropillars de‐swell and become stiff. This phase transition alters the lowest energy state of the system, resulting in a reversible clustering transition. To demonstrate, high‐aspect‐ratio micropillars of poly(N‐isopropylacrylamide‐co‐acrylamide) hydrogels are fabricated through a soft‐molding technique. The micropillars show the clustering transition, and the behavior is studied using a thermodynamic model. By controlling the temperature, the micropillars grip and release microparticles on‐demand.

Injectable Extracellular Matrix Microparticles Promote Heart Regeneration in Mice with Post-ischemic Heart Injury.

Ischemic heart injury causes permanent cardiomyocyte loss and fibrosis impairing cardiac function. Tissue derived biomaterials have shown promise as an injectable treatment for the post-ischemic heart. Specifically, decellularized extracellular matrix (dECM) is a protein rich suspension that forms a therapeutic hydrogel once injected and improves the heart post-injury response in rodents and pig models. Current dECM-derived biomaterials are delivered to the heart as a liquid dECM hydrogel precursor or colloidal suspension, which gels over several minutes. To increase the functionality of the dECM therapy, an injectable solid dECM microparticle formulation derived from heart tissue to control sizing and extend stability in aqueous conditions is developed. When delivered into the infarcted mouse heart, these dECM microparticles protect cardiac function promote vessel density and reduce left ventricular remodeling by sustained delivery of biomolecules. Longer retention, higher stiffness, and slower protein release of dECM microparticles are noted compared to liquid dECM hydrogel precursor. In addition, the dECM microparticle can be developed as a platform for macromolecule delivery. Together, the results suggest that dECM microparticles can be developed as a modular therapy for heart injury.

High circulating levels of CD62E+ and CD31+/Annexin V+ endothelium-derived microparticles in children with overweight/obesity: Evidence of early vascular damage

BackgroundObesity perturbs endothelium integrity, leading to endothelial activation, which predisposes the release of endothelium-derived microparticles (EMP). We measured the CD31+/annexin V+ and CD62E+ EMP levels to improve our understanding of their contribution to endothelial damage in children with overweight/obesity. Subject and methodsIn this cross-sectional study, 107 children with normal weight and 35 children with overweight/obesity were evaluated. Anthropometric measurement, blood pressure, biochemical profile was performed. Standardized flow cytometry methods were used to identify and quantify circulating CD31+/annexin V+ and CD62E+ EMP. ResultsChildren with overweight/obesity had significantly higher circulating levels of CD31+/annexin V+ (750 [600]) and CD62E+ (1400 [700]) EMP than those with normal weight (P < 0.001 for both). We found that EMP levels were positively correlated with body mass index (BMI), waist circumference, blood pressure, total cholesterol, low-density lipoprotein cholesterol (LDLc), and triglycerides. The multivariable logistic regression model revealed that the risks of having high EMP levels (> 75th percentile) were high in children with both large waist circumference and elevated LDLc level. Receiver operating characteristic (ROC) curves demonstrated that the LDLc levels showed significantly greater discrimination than waist circumference for both CD31+/annexin V+ (P = 0.031) as CD62E+ EMPs (P = 0.041). ConclusionsChildren with overweight/obesity have high circulating CD31+/annexin V+ and CD62E+ EMP levels, which may be an early sign of endothelial apoptosis and inflammatory activation in response to injury. These EMP levels were positively associated with several cardiometabolic risk factors. Our data underscore the negative influence of high-risk metabolic profiles on endothelial integrity in the early stages of childhood obesity.

Systemic effect of TiO2 micro- and nanoparticles after acute exposure in a murine model.

The surface of a biomedical implant can be a potential endogenous source of release of microparticles (MPs) and nanoparticles (NPs) into the biological environment. In addition, titanium particles from exogenous sources can enter the body through inhalation, ingestion, or dermal contact. The aim of this work was to evaluate the biological response of the lung, liver, and kidneys to acute exposure to titanium dioxide (TiO2 ). Male Wistar rats were intraperitoneally injected with a suspension of 45μm or 5 nm TiO2 particles. One month post-exposure, titanium concentration was determined spectrometrically (ICP-MS) in plasma and target organs. Blood smears and organ tissue samples were examined histopathologically, and oxidative metabolism was analyzed (superoxide anion by nitro blue tetrazolium (NBT) test; superoxide dismutase (SOD) and catalase (CAT); lipid peroxidation; paraoxonase 1). Liver (aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase) and kidney (urea, creatinine) function was evaluated using serum biochemical markers. Microchemical and histological analysis revealed the presence of particles, though no structural alterations, in TiO2 -exposed groups. NBT test showed an increase in the percentage of reactive cells and antioxidant enzyme consumption in lung samples in the 45μm and 5nm TiO2 -exposed groups. Only the 5nm particles caused a decrease in SOD and CAT activity in the liver. No changes in renal oxidative metabolism were observed in either of the TiO2 -exposed groups. Determination of serum biochemical markers and analysis of oxidative metabolism are not early bioindicators of tissue damage caused by TiO2 MPs and NPs.