PKCα Induced the Generation of Extracellular Vesicles in Activated Platelets to Promote Breast Cancer Metastasis.

Platelet extracellular vesicles (PEVs) play an important role in tumor development. However, the mechanisms underlying their biogenesis have not been fully elucidated. Protein kinase Cα (PKCα) is an important regulator of platelet activation, but the effect of PKCα on EV generation is unclear. We used small-particle flow cytometry and found that the number of PEVs was increased in patients with breast cancer compared to those with benign breast disease. This was accompanied by increased levels of activated PKCα in breast cancer platelets. Treating platelets with the PKCα agonist phorbol 12-myristate 13-acetate (PMA) increased the phosphorylation PKCα and induced PEV production, while the PKCα inhibitor GÖ6976 showed the opposite effects. Notably, incubating platelets from patients with benign tumors with the culture supernatant of MDA-MB-231 cells induced PKCα phosphorylation in the platelets. Mass spectrometry and coimmunoprecipitation assays showed that Dynamin 2 (DNM2), a member of the guanosine-triphosphate-binding protein family, might cooperate with activated PKCα to regulate PEV production by breast cancer platelets. Similar results were observed in a mouse model of lung metastasis. In addition, PEVs were engulfed by breast cancer cells and promoted cancer cell migration and invasion via miR-1297 delivery. These findings suggested that PKCα cooperates with DNM2 to induce PEV generation, and PEV release might triggered by factors in the breast cancer environment.

Streptococcus pneumoniae extracellular vesicles aggravate alveolar epithelial barrier disruption via autophagic degradation of OCLN (occludin).

Streptococcus pneumoniae (S. pneumoniae) represents a major human bacterial pathogen leading to high morbidity and mortality in children and the elderly. Recent research emphasizes the role of extracellular vesicles (EVs) in bacterial pathogenicity. However, the contribution of S. pneumoniae EVs (pEVs) to host-microbe interactions has remained unclear. Here, we observed that S. pneumoniae infections in mice led to severe lung injuries and alveolar epithelial barrier (AEB) dysfunction. Infections of S. pneumoniae reduced the protein expression of tight junction protein OCLN (occludin) and activated macroautophagy/autophagy in lung tissues of mice and A549 cells. Mechanically, S. pneumoniae induced autophagosomal degradation of OCLN leading to AEB impairment in the A549 monolayer. S. pneumoniae released the pEVs that could be internalized by alveolar epithelial cells. Through proteomics, we profiled the cargo proteins inside pEVs and found that these pEVs contained many virulence factors, among which we identified a eukaryotic-like serine-threonine kinase protein StkP. The internalized StkP could induce the phosphorylation of BECN1 (beclin 1) at Ser93 and Ser96 sites, initiating autophagy and resulting in autophagy-dependent OCLN degradation and AEB dysfunction. Finally, the deletion of stkP in S. pneumoniae completely protected infected mice from death, significantly alleviated OCLN degradation in vivo, and largely abolished the AEB disruption caused by pEVs in vitro. Overall, our results suggested that pEVs played a crucial role in the spread of S. pneumoniae virulence factors. The cargo protein StkP in pEVs could communicate with host target proteins and even hijack the BECN1 autophagy initiation pathway, contributing to AEB disruption and bacterial pathogenicity.Abbreviations: AEB: alveolarepithelial barrier; AECs: alveolar epithelial cells; ATG16L1: autophagy related 16 like 1; ATP:adenosine 5'-triphosphate; BafA1: bafilomycin A1; BBB: blood-brain barrier; CFU: colony-forming unit; co-IP: co-immunoprecipitation; CQ:chloroquine; CTRL: control; DiO: 3,3'-dioctadecylox-acarbocyanineperchlorate; DOX: doxycycline; DTT: dithiothreitol; ECIS: electricalcell-substrate impedance sensing; eGFP: enhanced green fluorescentprotein; ermR: erythromycin-resistance expression cassette; Ery: erythromycin; eSTKs: eukaryotic-like serine-threoninekinases; EVs: extracellular vesicles; HA: hemagglutinin; H&E: hematoxylin and eosin; HsLC3B: human LC3B; hpi: hours post-infection; IP: immunoprecipitation; KD: knockdown; KO: knockout; LAMP1: lysosomal associated membrane protein 1; LC/MS: liquid chromatography-mass spectrometry; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MVs: membranevesicles; NC:negative control; NETs:neutrophil extracellular traps; OD: optical density; OMVs: outer membrane vesicles; PBS: phosphate-buffered saline; pEVs: S.pneumoniaeextracellular vesicles; protK: proteinase K; Rapa: rapamycin; RNAi: RNA interference; S.aureus: Staphylococcusaureus; SNF:supernatant fluid; sgRNA: single guide RNA; S.pneumoniae: Streptococcuspneumoniae; S.suis: Streptococcussuis; TEER: trans-epithelium electrical resistance; moi: multiplicity ofinfection; TEM:transmission electron microscope; TJproteins: tight junction proteins; TJP1/ZO-1: tight junction protein1; TSA: tryptic soy agar; WB: western blot; WT: wild-type.

Liposomes and Other Nanocarriers for the Treatment of Acne Vulgaris: Improved Therapeutic Efficacy and Skin Tolerability.

Acne vulgaris is a common dermatologic disorder that affects approximately 85% of teenagers, which significantly impacts the quality of life in adolescents. It is a chronic disease of the sebaceous follicles that is multifactorial in etiology. Topical treatment is the first choice for mild and moderate acne, while systemic therapy is reserved for severe and certain moderate cases. Topical treatments include retinoids (e.g., tretinoin and adapalene), antibiotics (e.g., clindamycine), and other agents (e.g., benzoyl peroxide and azelaic acid), often applied in combination. The mechanisms of action include antimicrobial, anti-inflammatory, and keratolytic activities, as well as sebum secretion reduction, and the normalization of follicular keratinization. However, these topical agents commonly induce side effects, such as dryness, burning, stinging, peeling, redness, erythema, and photosensitivity. Therefore, there is a need to reduce the side effects of anti-acne drugs, while maintaining or enhancing their therapeutic effectiveness. This article aims to comprehensively outline nanotechnology strategies, particularly the use of phospholipid-based nanocarriers like liposomes and related vesicles, to enhance therapeutic efficacy, skin tolerability, and patient compliance in the treatment of acne vulgaris. In addition, novel active ingredients encapsulated in vesicles beyond those recommended in official guidelines are discussed.

Enhanced diabetic wound healing using platelet-derived extracellular vesicles and reduced graphene oxide in polymer-coordinated hydrogels.

Impaired wound healing is a significant complication of diabetes. Platelet-derived extracellular vesicles (pEVs), rich in growth factors and cytokines, show promise as a powerful biotherapy to modulate cellular proliferation, angiogenesis, immunomodulation, and inflammation. For practical home-based wound therapy, however, pEVs should be incorporated into wound bandages with careful attention to delivery strategies. In this work, a gelatin-alginate hydrogel (GelAlg) loaded with reduced graphene oxide (rGO) was fabricated, and its potential as a diabetic wound dressing was investigated. The GelAlg@rGO-pEV gel exhibited excellent mechanical stability and biocompatibility in vitro, with promising macrophage polarization and reactive oxygen species (ROS)-scavenging capability. In vitro cell migration experiments were complemented by in vivo investigations using a streptozotocin-induced diabetic rat wound model. When exposed to near-infrared light at 2 W cm- 2, the GelAlg@rGO-pEV hydrogel effectively decreased the expression of inflammatory biomarkers, regulated immune response, promoted angiogenesis, and enhanced diabetic wound healing. Interestingly, the GelAlg@rGO-pEV hydrogel also increased the expression of heat shock proteins involved in cellular protective pathways. These findings suggest that the engineered GelAlg@rGO-pEV hydrogel has the potential to serve as a wound dressing that can modulate immune responses, inflammation, angiogenesis, and follicle regeneration in diabetic wounds, potentially leading to accelerated healing of chronic wounds.

Platelet-derived extracellular vesicles promote endothelial dysfunction in sepsis by enhancing neutrophil extracellular traps.

BACKGROUND: The role of platelet-derived extracellular vesicles (PEVs) in the development of sepsis was investigated in this study. METHODS: After collection of blood samples from sepsis patients and normal volunteers, the extracellular vesicles (EVs) were separated, followed by the isolation of PEVs from the blood of rats. Next, a sepsis rat model was constructed by cecal ligation and puncture (CLP), and rats received tail vein injection of PEVs to explore the role of PEVs in sepsis. Subsequently, nanoparticle tracking analysis (NTA) and transmission electron microscopy (TEM) were adopted to determine the diameter of EVs and observe the morphology of PEVs, respectively; flow cytometry to detect the percentage of CD41-and CD61-positive EVs in isolated EVs; and ELISA to assess neutrophil extracellular trap (NET) formation, endothelial function injury-related markers in clinical samples or rat blood and serum inflammatory factor level. RESULTS: Compared with normal volunteers, the percentage of CD41- and CD61-positive EVs and the number of EVs were significantly elevated in sepsis patients. Moreover, sepsis patients also presented notably increased histone H3, myeloperoxidase (MPO), angiopoietin-2 and endocan levels in the blood, and such increase was positively correlated with the number of EVs. Also, animal experiments demonstrated that PEVs significantly promoted NET formation, mainly manifested as up-regulation of histone H3, high mobility group protein B1 (HMGB1), and MPO; promoted endothelial dysfunction (up-regulation of angiopoietin-2, endocan, and syndecan-1); and stimulated inflammatory response (up-regulation of interleukin (IL) -1ß, IL-6, tumor necrosis factor (TNF)-α, and monocyte chemoattractant protein (MCP) -1) in the blood of sepsis rats. CONCLUSION: PEVs aggravate endothelial function injury and inflammatory response in sepsis by promoting NET formation.

Shedding Light on the Cell Biology of Platelet-Derived Extracellular Vesicles and Their Biomedical Applications.

EVs are membranous subcellular structures originating from various cells, including platelets which consist of biomolecules that can modify the target cell's pathophysiological functions including inflammation, cell communication, coagulation, and metastasis. EVs, which are known to allow the transmission of a wide range of molecules between cells, are gaining popularity in the fields of subcellular treatment, regenerative medicine, and drug delivery. PEVs are the most abundant EVs in circulation, being produced by platelet activation, and are considered to have a significant role in coagulation. PEV cargo is extremely diverse, containing lipids, proteins, nucleic acids, and organelles depending on the condition that induced their release and can regulate a wide range of biological activities. PEVs, unlike platelets, can overcome tissue barriers, allowing platelet-derived contents to be transferred to target cells and organs that platelets cannot reach. Their isolation, characterization, and therapeutic efficacy, on the other hand, are poorly understood. This review summarizes the technical elements of PEV isolation and characterization methods as well as the pathophysiological role of PEVs, including therapeutic potential and translational possibility in diverse disciplines.

A double-edged sword of platelet-derived extracellular vesicles in tissues, injury or repair: The current research overview.

Extracellular vesicles (EVs) are vesicular bodies with a double-layered membrane structure that are detached from the cell membrane or secreted by the cells. EVs secreted by platelets account for the main part in the blood circulation, which account for about 30% or even more. Many types of cells are regulated by PEVs, including endothelial cells, leukocytes, smooth muscle cells, etc. Nevertheless, despite the growing interest in the study of extracellular vesicles, there are still only a few studies on the role of PEVs. Therefore, this overview mainly focuses on one method of isolation and the functions of PEVs in tissues found so far, including promoting tissue repair and mediating tissue damage, which can be used for researchers to continue to explore the role of PEVs in other fields.

Advanced application of stimuli-responsive drug delivery system for inflammatory arthritis treatment.

Inflammatory arthritis is a major cause of disability in the elderly. This condition causes joint pain, loss of function, and deterioration of quality of life, mainly due to osteoarthritis (OA) and rheumatoid arthritis (RA). Currently, available treatment options for inflammatory arthritis include anti-inflammatory medications administered via oral, topical, or intra-articular routes, surgery, and physical rehabilitation. Novel alternative approaches to managing inflammatory arthritis, so far, remain the grand challenge owing to catastrophic financial burden and insignificant therapeutic benefit. In the view of non-targeted systemic cytotoxicity and limited bioavailability of drug therapies, a major concern is to establish stimuli-responsive drug delivery systems using nanomaterials with on-off switching potential for biomedical applications. This review summarizes the advanced applications of triggerable nanomaterials dependent on various internal stimuli (including reduction-oxidation (redox), pH, and enzymes) and external stimuli (including temperature, ultrasound (US), magnetic, photo, voltage, and mechanical friction). The review also explores the progress and challenges with the use of stimuli-responsive nanomaterials to manage inflammatory arthritis based on pathological changes, including cartilage degeneration, synovitis, and subchondral bone destruction. Exposure to appropriate stimuli induced by such histopathological alterations can trigger the release of therapeutic medications, imperative in the joint-targeted treatment of inflammatory arthritis.

Nanomedicine for acute respiratory distress syndrome: The latest application, targeting strategy, and rational design.

Acute respiratory distress syndrome (ARDS) is characterized by the severe inflammation and destruction of the lung air-blood barrier, leading to irreversible and substantial respiratory function damage. Patients with coronavirus disease 2019 (COVID-19) have been encountered with a high risk of ARDS, underscoring the urgency for exploiting effective therapy. However, proper medications for ARDS are still lacking due to poor pharmacokinetics, non-specific side effects, inability to surmount pulmonary barrier, and inadequate management of heterogeneity. The increased lung permeability in the pathological environment of ARDS may contribute to nanoparticle-mediated passive targeting delivery. Nanomedicine has demonstrated unique advantages in solving the dilemma of ARDS drug therapy, which can address the shortcomings and limitations of traditional anti-inflammatory or antioxidant drug treatment. Through passive, active, or physicochemical targeting, nanocarriers can interact with lung epithelium/endothelium and inflammatory cells to reverse abnormal changes and restore homeostasis of the pulmonary environment, thereby showing good therapeutic activity and reduced toxicity. This article reviews the latest applications of nanomedicine in pre-clinical ARDS therapy, highlights the strategies for targeted treatment of lung inflammation, presents the innovative drug delivery systems, and provides inspiration for strengthening the therapeutic effect of nanomedicine-based treatment.

What's new in the field of phospholipid vesicular nanocarriers for skin drug delivery.

Over the last three decades, research in the field of phospholipid nanocarriers as tools to improve dermal and transdermal drug delivery has grown substantially. In particular, liposomes have been the target of studies aimed at reformulating vesicles with a greater ability to deliver drugs trans-dermally. A number of additives with varied physicochemical properties have been combined with traditional components of liposomes. These novel modification processes have produced new classes of vesicles with the potential to enhance the treatment of both dermatological disorders and systemic pathologies. Development of the first deformable and elastic phospholipid vesicles has highlighted the key role of vesicle composition in promoting release of vesicle content into and through the skin. This paper discusses the key vesicle properties and mechanisms of delivery by which newly developed phospholipid vesicles can improve percutaneous drug delivery.

Transdermal lipid vesicular delivery of iloperidone: Formulation, in vitro and in vivo evaluation.

The objective of present study was to develop and evaluate lipid vesicular transdermal system of iloperidone. Liposomes were prepared successfully using thin film hydration method. With aim of enhancing permeation, cholesterol from liposomes was replaced with transcutol to give PEVs. Liposomes and PEVs were evaluated for particle size, shape, entrapment efficiency, viscosity and release study. The vesicles were incorporated in 0.5% of Carbopol gel and evaluated. Particle size of liposomes and PEVs was found between 200-300 nm and entrapment efficiency was found 80-90%w/w. The transdermal gels were homogeneous, spreadable having acceptable pH and drug content between 90-100%.In ex vivo studies, both liposomes and PEVs showed relatively higher skin deposition and permeation of Iloperidone than the plain drug without vesicles. The in vivo pharmacokinetics studies showed relative bioavailability of the PEV loaded gel as 62% and 166% when compared to the oral drug and gel without vesicles respectively. Pharmacodynamic studies showed FRT and HRT delay responses of the transdermal gel systems were significant[p < 0.05] as compared to control at the end of 24 hs. Thus, it can be concluded that transdermal delivery system can be a promising approach for sustained delivery of Iloperidone.

Molecular arrangements and interconnected bilayer formation induced by alcohol or polyalcohol in phospholipid vesicles.

A self-assembled hybrid phospholipid vesicular system containing various penetration enhancers - ethanol, Transcutol and propylenglycol - was prepared and characterized. The effects of the different alcohol or polyalcohols structure and their concentration on the features of the assembled vesicles were evaluated using a combination of different techniques, including cryo-transmission electron microscopy, laser light scattering, differential scanning calorimetry, small- and wide-angle X-ray scattering and rheological analysis. These techniques allow explaining the structural rearrangements of the bilayer assembly due to the alcohol or polyalcohol addition. X-ray scattering studies showed that such addition at the highest concentration (20%) allowed structure modification to oligolamellar vesicles and a bilayer transition to interdigitated phase. Rheological studies confirmed the importance of alcohol or polyalcohol in the structuring dispersions probably due to a partial tilting of phosphatidylcholine acyl chains forming interdigitated and interconnected bilayer vesicles.