Platelet secretion: From haemostasis to wound healing and beyond

Metabolic crosstalk between platelets and cancer: Mechanisms, functions, and therapeutic potential

Platelets, traditionally regarded as passive mediators of hemostasis, are now recognized as pivotal regulators in the tumor microenvironment, establishing metabolic feedback loops with tumor and immune cells. Tumor-derived signals trigger platelet activation, which induces rapid metabolic reprogramming, particularly glycolysis, to support activation-dependent functions such as granule secretion, morphological changes, and aggregation. Beyond self-regulation, platelets influence the metabolic processes of adjacent cells. Through direct mitochondrial transfer, platelets reprogram tumor and immune cells, promoting oxidative phosphorylation. Additionally, platelet-derived cytokines, granules, and extracellular vesicles drive metabolic alterations in immune cells, fostering suppressive phenotypes that facilitate tumor progression. This review examines three critical aspects: (1) the distinctive metabolic features of platelets, particularly under tumor-induced activation; (2) the metabolic crosstalk between activated platelets and other cellular components; and (3) the therapeutic potential of targeting platelet metabolism to disrupt tumor-promoting networks. By elucidating platelet metabolism, this review highlights its essential role in tumor biology and its therapeutic implications.

Novel tissue biomarker candidates to predict both deep venous thrombosis and healing outcome after Achilles tendon rupture

Deep venous thrombosis (DVT) and poor long-term patient outcomes frequently occur in patients with Achilles tendon rupture (ATR). Biomarkers for DVT and their possible relationship to long-term healing outcomes remain unexplored. To identify DVT biomarkers from proteomic profiles during the inflammatory and proliferative healing stages and assess their associations with one-year healing outcomes after surgical repair of ATR. A cohort of 53 patients undergoing standardized ATR repair from previous clinical trials was investigated. Intraoperative inflammatory-stage tendon biopsies were obtained from 40 patients, and tendon microdialysates from 28 patients were collected two weeks later during the proliferative stage. Liquid chromatography-tandem mass spectrometry proteomic profiles were linked to DVT status at two weeks post-surgery using ultrasonography screening and to patient-reported outcomes at one-year post-surgery. Six candidate DVT biomarkers were identified from tendon biopsies, whereof four (ABI3BP, IGKV2-40/IGKV2D-40, PCYOX1, STIP1) were associated with one-year healing outcomes. In tendon microdialysates, 43 candidate DVT biomarkers were identified, but none were associated with healing outcomes. Bioinformatic analysis revealed pathways related to heat shock response, platelet signaling, collagen and extracellular matrix metabolism, and immunoglobulins. The results support shared inflammatory-stage protein pathways in regulating venous thrombosis and reported healing outcomes, where elements of individual hypoxic tolerance and platelet signaling emerge as potential key links.

Cardiovascular disease and thrombosis: Intersections with the immune system, inflammation, and the coagulation system

The coagulation and immune system, both essential physiological systems in the human body, are intricately interconnected and play a critical role in determining the overall health of patients. These systems collaborate via various shared regulatory pathways, such as the Tissue Factor (TF) Pathway. Immunological cells that express TF and generate pro-inflammatory cytokines have the ability to affect coagulation. Conversely, coagulation factors and processes have a reciprocal effect on immunological responses by stimulating immune cells and regulating their functions. These interconnected pathways play a role in both preserving well-being and contributing to a range of pathological disorders. The close relationship between blood clotting and inflammation in the development of vascular disease has become a central focus of clinical study. This research specifically examines the crucial elements of this interaction within the contexts of cardiovascular disease and acute coronary syndrome. Tissue factor, the primary trigger of the extrinsic coagulation pathway, has a crucial function by inducing a proinflammatory reaction through the activation of coagulation factors. This, in turn, initiates coagulation and subsequent cellular signalling pathways. Protease-activated receptors establish the molecular connection between coagulation and inflammation by interacting with activated clotting factors II, X, and VII. Thrombosis, a condition characterised by the formation of blood clots, is the most dreaded consequence of cardiovascular disorders and a leading cause of death globally. Consequently, it poses a significant challenge to healthcare systems. Antithrombotic treatments efficiently target platelets and the coagulation cascade, but they come with the inherent danger of causing bleeding. Furthermore, antithrombotics are unable to fully eliminate thrombotic events, highlighting a treatment deficiency caused by a third mechanism that has not yet been sufficiently addressed, namely inflammation. Understanding these connections may aid in the development of novel approaches to mitigate the harmful mutual exacerbation of inflammation and coagulation. Gaining a comprehensive understanding of the intricate interaction among these systems is crucial for the management of diseases and the creation of efficacious remedies. Through the examination of these prevalent regulatory systems, we can discover novel therapeutic approaches that specifically target these complex illnesses. This paper provides a thorough examination of the reciprocal relationship between the coagulation and immune systems, emphasising its importance in maintaining health and understanding disease processes. This review examines the interplay between inflammation and thrombosis and its role in the development of thrombotic disorders.

Exploring effects of platelet contractility on the kinetics, thermodynamics, and mechanisms of fibrin clot contraction

Mechanisms of blood clot contraction - platelet-driven fibrin network remodeling, are not fully understood. We developed a detailed computational ClotDynaMo model of fibrin network with activated platelets, whose clot contraction rate for normal 450,000/µl human platelets depends on serum viscosity η, platelet filopodia length l, and weakly depends on filopodia traction force f and filopodia extension-retraction speed v. Final clot volume is independent of η, but depends on v, f and l. Analysis of ClotDynaMo output revealed a 2.24 TJ/mol clot contraction free energy change, with ~67% entropy and ~33% internal energy changes. The results illuminate the "optimal contraction principle" that maximizes volume change while minimizing energy cost. An 8-chain continuum model of polymer elasticity containing platelet forces, captures clot contractility as a function of platelet count, η and l. The ClotDynaMo and continuum models can be extended to include red blood cells, variable platelet properties, and mechanics of fibrin network.

Chinese herbal medicine-inspired construction of multi-component hydrogels with antibacterial and wound-healing-promoting functions

Chinese herbal medicine (CHM) has offered a great treasure and source of inspiration for developing innovative medicinal materials and therapy. In this work, inspired by the macroscopic compatibility of Puerariae Lobatae Radix and Gypsum Ustum in CHM, the puerarin (PUE) and CaSO4 (Ca) as the main constituents, respectively, from the two herbs are co-assembled into two-component molecular hydrogels. Such two-component gels exhibited enhanced mechanical properties compared with the single-component PUE gel due to the introduction of crosslinking hydrogen bonds between PUE and Ca. Importantly, the two-component gels show good biocompatibility and antibacterial and antioxidant properties. Moreover, in vivo wound healing experiments on an E. coli-infected mouse model together with the histological and immunological analyses were conducted, revealing that the two-component gels possessed good wound-healing-promoting functions. Our research shows how the medication practice of CHM can contribute to the development of novel bio-soft materials. It is anticipated that more herbal medicine-inspired medicinal materials will be built and tailored for specific bio-applications.

Deciphering Platelets: Are They Cells or an Evolved Form of Extracellular Vesicles?

Platelets are abundant in blood, where they maintain the integrity of the vasculature. Megakaryocytes, the cells responsible for platelet genesis, produce membrane protrusions from which as many as 5000 anucleate platelets can be released into the bloodstream. Platelets lack genomic DNA but contain different molecules, such as RNA, as well as organelles transmitted from the parent megakaryocyte. There is no consensus in the scientific community on whether platelets are cells or not: for example, they are sometimes called cells, small cells, anucleated cells, cell fragments, or megakaryocyte fragments. Extracellular vesicles are particles delimited by a lipid bilayer that are released from cells but cannot replicate on their own. Like platelets, extracellular vesicles lack a nucleus and carry components from their donor cell. Herein, we will explore various viewpoints suggesting that platelets may be cells, albeit not conventional cells, or may be a previously unrecognized type of extracellular vesicle. Beyond a mere debate over terminology, this perspective seeks to help properly define and classify platelets, aiming for better integration into the concept of either cells or extracellular vesicles. This will foster a clearer understanding and drive advances in platelet research.

The role of hyperbaric oxygen therapy in the treatment of diabetic foot ulcers - A literature review

Diabetic Foot Ulcers (DFUs) are chronic foot wounds, in a person with diabetes, which are associated with peripheral arterial insufficiency and/or peripheral neuropathy of the lower limb. Recent UK audit figures report that approximately 50-60 % of DFUs remain unhealed after 12 weeks. Previous research has suggested that ischaemia plays a key role in the pathophysiology of many chronic wounds, including DFUs. For this reason, hyperbaric oxygen therapy (HOT) has been investigated. The study aimed to investigate 1) Current understanding of the physiology of normal wound healing and the pathological mechanisms that occur in DFUs to interrupt these processes; 2) Effectiveness of current DFU treatment approaches; 3) Effectiveness from clinical trials and meta-analyses for any demonstrated therapeutic benefits of HOT in the treatment of DFUs, 4) Patient selection criteria for HOT, and patients who stand to benefit most from treatment. The review found that wound healing is a complex process, involving many cells and signalling molecules, and it remains incompletely understood. However, current evidence suggests that hyperglycaemia, hypoxia, chronic inflammation (due to infection, immune-cell dysfunction or other causes), peripheral neuropathy, and macro- and micro-vascular dysfunction may all adversely affect DFU healing. The review found that current NICE guidelines do not approve HOT therapy in the UK for DFU's, despite encouraging clinical research findings. HOT shows theoretical promise and has been successfully used in the treatment of individual DFUs for several decades. Despite this, there remains a lack of strong clinical evidence of benefits to encourage HOT's wider use. The review found that there were four important patient selection criteria for HOT treatment, including glycaemic control, possible contraindications and complications associated with treatment, ulcer severity and resistance to first and second line treatments. The review concluded that further high-quality clinical research is needed to improve the evidence base.

Analysis of Ferric Protoporphyrin IX Effects on Human Platelets: Hematin Is a More Potent Agonist than Hemin

Hemolysis during severe diseases (malaria, hemorrhagic stroke, sickle cell disease, etc.) and blood transfusion induces the release of free hemoglobin, which degrades to highly reactive and toxic compounds-hemin and hematin. Oxidized heme derivatives induce platelet activation, aggregation, and degranulation, leading to prothrombotic and inflammatory events. In the present study, we showed that hematin is a more potent agonist of platelet activation than hemin, and using several methods, including the original laser diffraction method, flow cytometry, and confocal microscopy, we demonstrated that hematin at low doses induces platelet activation and aggregation without reducing cell viability and affecting calcium efflux. On the contrary, hematin at high concentrations triggered phosphatidylserine exposure, severe loss of platelet viability, and calcium dysregulation, which was not inhibited by cGMP/PKG and cAMP/PKA pathways. Additionally, we showed that albumin could initiate disaggregation processes in hematin-activated platelets.

P2Y12 receptor-independent antiplatelet mechanism of cryptotanshinone: Network pharmacology and experimental validation of multi-target signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Cryptotanshinone serves as the principal bioactive constituent of Salvia miltiorrhiza Bunge, possesses a wide range of pharmacological activities. Salvia miltiorrhiza Bunge, a long-standing therapeutic agent in traditional Chinese medicine (TCM) practice, is renowned for its efficacy in enhancing blood circulation and alleviating blood stasis and infarction, thereby treating cardiovascular and cerebrovascular diseases.

AIM OF THE STUDY

Platelet activation, when excessive or aberrant, poses a significant risk, catalyzing the onset of various thrombotic disorders. Thus, this investigation is meticulously designed to assess the antiplatelet pharmacological activity of cryptotanshinone, delving into its mechanisms of action that operate independently of the P2Y12 receptor.

MATERIALS AND METHODS

We employed a combination of isolated human platelet functional analysis, network pharmacology, molecular docking, and animal experiments to explore the P2Y12 receptor-independent antiplatelet targets and the biological mechanisms by which cryptotanshinone improves thrombosis.

RESULTS

Utilizing the ADP-hydrolyzing enzyme apyrase, we isolated the direct effects of cryptotanshinone on platelet function. The findings reveal that cryptotanshinone can effectively inhibit platelet activation in a manner that is independent of the P2Y12 receptor, all the while maintaining normal tail bleeding times in murine models and not exacerbating mesenteric thrombosis. These effects appear to be mediated through intricate signaling pathways, including PI3K-AKT, MAPK, and STAT3.

CONCLUSION

This study compellingly confirms the capacity of cryptotanshinone to suppress platelet function independently of the P2Y12 receptor, establishing a robust theoretical foundation for innovative strategies in thrombosis prevention.

miRNAs and their multifaceted role in cutaneous wound healing

The dynamic, complex process of cutaneous wound healing is required to restore skin integrity following an injury. This intricate process consists of four sequential and overlapping phases: hemostasis, inflammation, proliferation, and remodeling. Hemostasis immediately begins to function in response to vascular injury, forming a clot that stops the bleeding. To fight infection and remove debris, immune cells are enlisted during the inflammatory phase. Angiogenesis, re-epithelialization, and the creation of new tissue are all components of proliferation, whereas tissue maturation and scarring are the outcomes of remodeling. Chronic wounds, like those found in diabetic ulcers, frequently stay in a state of chronic inflammation because they are unable to go through these stages in a coordinated manner. The important regulatory roles that microRNAs (miRNAs) play in both normal and pathological wound healing have been highlighted by recent investigations. The miRNAs, small non-coding RNAs, modulate gene expression post-transcriptionally, profoundly impacting cellular functions. During the inflammatory phase, miRNAs control pro- and anti-inflammatory cytokines, as well as the activity of immune cells such as neutrophils and macrophages. Additionally, miRNAs are essential components of signaling networks related to inflammation, such as the toll-like receptor (TLR), nuclear factor kappa B (NF-kB), and Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathways. Some miRNAs have been discovered to either increase or alleviate inflammatory reactions, indicating their potential as therapeutic targets. Other miRNAs aid in angiogenesis by promoting the development of new blood vessels, which are essential for providing oxygen and nutrients to the healing tissue. They also affect keratinocyte migration and proliferation during the re-epithelialization phase, which involves growing new epithelial cells over the lesion. Another function of miRNAs is that they control the deposition of extracellular matrix (ECM) and the creation of scars during the remodeling phase. The abnormal expression of miRNAs in chronic wounds has led to the exploration of miRNA-based treatments. With a focus on resistant instances such as diabetic wounds, these therapeutic techniques seek to improve wound healing results by correcting the dysregulated miRNA expression.

Platelet endocytosis and α-granule cargo packaging are essential for normal skin wound healing

The high prevalence of chronic wounds, i.e., 2.5-3% of the US population, causes a large social and financial burden. Physiological wound healing is a multi-step process that involves different cell types and growth factors. Platelet-rich plasma or platelet-derived factors have been used to accelerate wound repair, but their use has been controversial with mixed results. Thus, a detailed functional understanding of platelet functions in wound healing beyond hemostasis is needed. This study investigated the importance of platelet α-granule cargo packaging and endocytosis in a dorsal full-thickness excisional skin wound model using mice with defects in α-granule cargo packaging (Nbeal2 -/- mice) and endocytosis (platelet-specific Arf6 -/- and VAMP2/3 Δ mice). We found that proper kinetic and morphological healing of dorsal skin wounds in mice requires both de novo as well as endocytosed platelet α-granule cargo. Histological and morphometric analyses of cross-sectional wound sections illustrated that mice with defects in α-granule cargo packaging or platelet endocytosis had delayed (epi)dermal regeneration in both earlier and advanced healing. This was reflected by reductions in wound collagen and muscle/keratin content, delayed scab formation and/or resolution, re-epithelialization, and cell migration and proliferation. Molecular profiling analysis of wound extracts showed that the impact of platelet function extends beyond hemostasis to the inflammation, proliferation, and tissue remodeling phases via altered expression of several bioactive molecules, including IL-1β, VEGF, MMP-9, and TIMP-1. These findings provide a basis for advances in clinical wound care through a better understanding of key mechanistic processes and cellular interactions in (patho)physiological wound healing.

Key points

De novo and endocytosed platelet α-granule cargo support physiological skin wound healing Platelet function in wound healing extends to the inflammation, proliferation, and tissue remodeling phases.

The effects of changes in thrombocyte indices, on-on-pump time on prognosis in open heart surgery

Extracorporeal perfusion systems utilized in open-heart surgeries with cardiopulmonary bypass can affect multiple body systems. The primary adverse effects of Extracorporeal Perfusion Systems (EPS) on the hematological system include postoperative bleeding and coagulation issues. The aim of this study is to evaluate the effects of on-pump time and cross-clamp duration on total platelet count (PLT) and platelet indices in open-heart surgeries performed using cardiopulmonary bypass. This evaluation is achieved by comparing PLT, mean platelet volume (MPV), platelet distribution width (PDW), and plateletcrit (PCT) before and after surgery. For this study, the laboratory results of a total of 392 patients who underwent open-heart surgery with cardiopulmonary bypass at the Department of Cardiovascular Surgery, Istanbul University Cerrahpaşa Institute of Cardiology, between 2017 and 2018 were retrospectively analyzed. The stepwise multiple linear regression model, in which postoperative PLT was the dependent variable and other parameters were independent variables, revealed that the main determinants of the significant change in postoperative PLT were the duration of device use, along with preoperative PLT and PDW. Our results indicate that on-pump time, along with preoperative PLT and PDW values, is the primary determinants of changes in PLT and PCT in open-heart surgeries with cardiopulmonary bypass. Considering the patient's preoperative platelet count and PDW values in such surgeries may be useful in preventing postoperative adverse events.

Human platelet lysate: a potential therapeutic for intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a major public health challenge worldwide, and is associated with elevated rates of mortality, disability, and morbidity, especially in low- and middle-income nations. However, our knowledge of the detailed molecular processes involved in ICH remains insufficient, particularly those involved in the secondary injury stage, resulting in a lack of effective treatments for ICH. Human platelet lysates (HPL) are abundant in bioactive factors, and numerous studies have demonstrated their beneficial effects on neurological diseases, including their anti-neuroinflammatory ability, anti-oxidant effects, maintenance of blood-brain barrier integrity, and promotion of neurogenesis. In this review, we thoroughly explore the potential of HPL for treating ICH from three critical perspectives: the rationale for selecting HPL as a treatment for ICH, the mechanisms through which HPL contributes to ICH management, and the additional measures necessary for HPL as a treatment for ICH. We elucidate the role of platelets in ICH pathophysiology and highlight the limitations of the current treatment options and advancements in preclinical research on the application of HPL in neurological disorders. Furthermore, historical developments and preparation methods of HPL in the field of biomedicine are discussed. Additionally, we summarize the bioactive molecules present in HPL and their potential therapeutic effects in ICH. Finally, we outline the issues that must be addressed regarding utilizing HPL as a treatment modality for ICH.

The biological role and future therapeutic uses of nitric oxide in extracorporeal membrane oxygenation, a narrative review

BACKGROUND

Nitric oxide (NO) is a gas naturally produced by the human body that plays an important physiological role. Specifically, it binds guanylyl cyclase to induce smooth muscle relaxation. NO's other protective functions have been well documented, particularly its protective endothelial functions, effects on decreasing pulmonary vascular resistance, antiplatelet, and anticoagulation properties. The use of nitric oxide donors as vasodilators has been known since 1876. Inhaled nitric oxide has been used as a pulmonary vasodilator and to improve ventilation perfusion matching since the 1990s. It is currently approved by the United States Food and Drug Administration for neonates with hypoxic respiratory failure, however, it is used off-label for acute respiratory distress syndrome, acute bronchiolitis, and COVID-19.

PURPOSE

In this article we review the currently understood biological action and therapeutic uses of NO through nitric oxide donors such as inhaled nitric oxide. We will then explore recent studies describing use of NO in cardiopulmonary bypass and extracorporeal membrane oxygenation and speculate on NO's future uses.

Oxymatrine, a novel TLR2 agonist, promotes megakaryopoiesis and thrombopoiesis through the STING/NF-κB pathway

Radiation-induced thrombocytopenia (RIT) faces a perplexing challenge in the clinical treatment of cancer patients, and current therapeutic approaches are inadequate in the clinical settings. In this research, oxymatrine, a new molecule capable of healing RIT was screened out, and the underlying regulatory mechanism associated with magakaryocyte (MK) differentiation and thrombopoiesis was demonstrated. The capacity of oxymatrine to induce MK differentiation was verified in K-562 and Meg-01 cells in vitro. The ability to induce thrombopoiesis was subsequently demonstrated in Tg (cd41:enhanced green fluorescent protein (eGFP)) zebrafish and RIT model mice. In addition, we carried out network pharmacological prediction, drug affinity responsive target stability assay (DARTS) and cellular thermal shift assay (CETSA) analyses to explore the potential targets of oxymatrine. Moreover, the pathway underlying the effects of oxymatrine was determined by Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, Western blot (WB), and immunofluorescence. Oxymatrine markedly promoted MK differentiation and maturation in vitro. Moreover, oxymatrine induced thrombopoiesis in Tg (cd41:eGFP) zebrafish and accelerated thrombopoiesis and platelet function recovery in RIT model mice. Mechanistically, oxymatrine directly binds to toll-like receptor 2 (TLR2) and further regulates the downstream pathway stimulator of interferon genes (STING)/nuclear factor-kappaB (NF-κB), which can be blocked by C29 and C-176, which are specific inhibitors of TLR2 and STING, respectively. Taken together, we demonstrated that oxymatrine, a novel TLR2 agonist, plays a critical role in accelerating MK differentiation and thrombopoiesis via the STING/NF-κB axis, suggesting that oxymatrine is a promising candidate for RIT therapy.

Genetic engineering of megakaryocytes from blood progenitor cells using messenger RNA lipid nanoparticles

BACKGROUND

Platelets are an essential component of hemorrhage control and management, and engineering platelets to express therapeutic proteins could expand their use as a cell therapy. Genetically engineered platelets can be achieved by modifying the platelet precursor cells, megakaryocytes (MKs). Current strategies include transfecting MK progenitors ex vivo with viral vectors harboring lineage-driven transgenes and inducing the production of in vitro modified platelets. The use of viruses, however, poses challenges in clinical implementation, and no methods currently exist to genetically modify MKs with nonviral techniques. Lipid nanoparticles (LNPs) are a nonviral delivery system that could enable a facile strategy to modify MKs with a variety of nucleic acid payloads.

OBJECTIVES

To investigate whether LNPs can transfect cultured hematopoietic stem/progenitor cell-derived MKs to express exogenous proteins and induce functional changes.

METHODS

MK and MK progenitors differentiated from cord blood-derived hematopoietic stem/progenitor cells were treated with LNP formulations containing messenger RNA and resembling the clinically approved LNP formulations. Transfection efficiency was assessed through flow cytometry by expression of enhanced green fluorescent protein. Functional changes to the MKs were assessed through rotational thromboelastometry by expression of exogenous coagulation factor (F)VII, a representative physiologically relevant protein.

RESULTS

LNPs enabled transfection efficiencies of 99% in MKs and did not impair MK maturation, viability, and morphology. MKs engineered to express exogenous FVII decreased clotting time in FVII-deficient plasma following clot initiation.

CONCLUSION

This approach provides an easy-to-use modular platform to genetically modify MK and MK progenitors, which can be potentially extended to producing genetically modified cultured platelets.

α-Synuclein Deletion Impairs Platelet Function: A Role for SNARE Complex Assembly

Granule secretion is an essential platelet function that contributes not only to haemostasis but also to wound healing, inflammation, and atherosclerosis. Granule secretion from platelets is facilitated, at least in part, by Soluble N-ethylmaleimide-Sensitive Factor (NSF) Attachment Protein Receptor (SNARE) complex-mediated granule fusion. Although α-synuclein is a protein known to modulate the assembly of the SNARE complex in other cells, its role in platelet function remains poorly understood. In this study, we provide evidence that α-synuclein is critical for haemostasis using α-synuclein-deficient (-/-) mice. The genetic deletion of α-synuclein resulted in impaired platelet aggregation, secretion, and adhesion in vitro. In vivo haemostasis models showed that α-synuclein-/- mice had prolonged bleeding times and activated partial thromboplastin times (aPTTs). Mechanistically, platelet activation induced α-synuclein serine (ser) 129 phosphorylation and re-localisation to the platelet membrane, accompanied by an increased association with VAMP 8, syntaxin 4, and syntaxin 11. This phosphorylation was calcium (Ca2+)- and RhoA/ROCK-dependent and was inhibited by prostacyclin (PGI2). Our data suggest that α-synuclein regulates platelet secretion by facilitating SNARE complex formation.

Serotonin-functionalized starch-based hemostatic sponges enhance platelet activation in the management of non-compressible hemorrhage

Massive hemorrhage poses a serious threat to human health and even life. Access to rapid and potent hemostatic materials is crucial for lowering mortality rates. Starch-based materials exhibit good biocompatibility and are extensively utilized in hemostatic. However, existing starch-based hemostatic products suffer from limited hemostatic efficacy. Serotonin, an indoleamine naturally occurring in the human body, is recognized for its potent platelet-activating properties. Therefore, this study focused on enhancing the procoagulant activity of starch by incorporating serotonin into the starch backbone via esterification and amidation reactions, yielding a novel serotonin-loaded starch-based hemostatic sponge (SLS sponge). The SLS sponges featured exceptional porosity (≥80 %) and water absorption capacity (≥2000 %), which rapidly initiated the coagulation cascade reaction, promoted the adhesion and aggregation of red blood cells and platelets, and intensified platelet activation. This multifaceted approach synergistically enhanced hemostasis via both active and passive coagulation mechanisms. Notably, the SLS sponges adhered firmly to the wound surfaces without pressure. Compared with gelatin sponges, the SLS sponges significantly reduced blood loss by approximately 40.5 % and shortened the time to achieve hemostasis by approximately 28.9 %. These findings indicate that the newly developed SLS sponges are a promising active hemostatic material, particularly effective in managing non-compressible hemorrhages.

Platelet interaction and performance of antibacterial bioinspired nanostructures passivated with human plasma

The ever-increasing ageing of the world population is demanding superior orthopedic devices. Issues such as implant infection, poor osseointegration, or chronic inflammation remain problematic to the lifespan and long-term efficacy of implants. Fabrication of materials with bioinspired nanostructures is one emerging antibacterial strategy to prevent implant infection, however their interactions with blood components, and whether they retain their bactericidal properties in an environment displaying a complex protein corona, remains largely unexplored. In the present study, titanium alloy, commercially pure and plasma-sprayed titania were hydrothermally etched, passivated with human native plasma to develop a protein corona, and then incubated with either Staphylococcus aureus, Pseudomonas aeruginosa or human platelets. Surface analysis was first used to characterize the topography, chemical composition or crystallinity of each material. Fluorescence staining and SEM were performed to evaluate the nanostructure bactericidal properties, as well as to study platelet attachment and morphology. Composition of platelet supernatant was studied using ELISA and flow cytometry. Overall, our study showed that the bioinspired nanostructured surfaces displayed both impressive antibacterial properties in a complex environment, and a superior blood biocompatibility profile in terms of platelet activation (particularly for titanium alloy). Additionally, the amount of pro-inflammatory cytokines released by platelets was found to be no different to that found in native plasma (background levels) and, in some cases, presented a more pro-healing profile with an increased secretion of factors such as TGF-β, PDGF-BB or BMP-2. The nanostructured surfaces performed equally, or better, than hydroxyapatite-coated titanium which is one of the current gold standards in orthopedics. Although further in vivo studies are required to validate these results, such bioinspired nanostructured surfaces certainly show promise to be safely applied to medical device surfaces used in orthopedics and other areas.

Recent advances in coaxial electrospun nanofibers for wound healing

The skin is the body's primary immune barrier, defending it against pathogenic invasion. Skin injuries impose a significant physiological burden on patients, making effective wound management essential. Dressings are commonly employed in wound care, and electrospun nanofiber dressings are a research hotspot owing to their ease of fabrication, cost-effectiveness, and structural similarity to the extracellular matrix. Coaxial electrospinning offers considerable advantages in drug delivery, fiber structure transformation, and enhanced interaction with the host. These attributes make coaxial electrospun materials promising candidates for precision and personalized wound dressings in medical treatments. This review provides a comprehensive overview of wound healing and its influencing factors. It also outlines coaxial electrospinning's production principles and benefits in wound dressings. Guided by the factors affecting wound healing, coaxial electrospun nanofiber dressings have different application modalities. Furthermore, we discuss the current limitations and future directions for enhancing the current coaxial electrospun dressing technologies.

Genetic engineering of transfusable platelets with mRNA-lipid nanoparticles is compatible with blood banking practices

ABSTRACT

Platelets contribute to a variety of physiological processes, including inflammation, sepsis, and cancer. However, because of their primary role in hemostasis, platelet transfusions are largely restricted to managing thrombocytopenia and bleeding. One way to expand the utility of platelet transfusions would be to genetically engineer donor platelets with new or enhanced functions. We have previously shown that lipid nanoparticles containing mRNA (mRNA-LNP) can be used to genetically modify authentic platelets in a nonclinical crystalloid solution. Currently, platelets collected for transfusion are stored in plasma or in plasma supplemented with platelet additive solution (PAS) at supraphysiological concentrations at room temperature, or at 4°C if intended for use in acute hemorrhage. Here, we describe a new plasma-optimized mRNA-LNP for transfecting platelets directly in plasma and plasma supplemented with PAS that is scalable to physiological and supraphysiological platelet concentrations. Transfecting platelets in clinical solutions with mRNA-LNP does not affect aspects of in vitro physiology, and transfected platelets are storable. The compatibility of this transfection system with current clinical practices could enable future mRNA-LNP-based platelet products and cell therapies.

Impact of 6-hydroxydopamine on agonist-induced human platelet functional parameters: An explanation for platelet impairment in Parkinson's disease

Parkinson's disease (PD) is the second-most prevalent neurodegenerative disease worldwide, which worsens with advancing age. It is a common movement disorder and is often associated with several vascular diseases with decreased stroke frequency. Circulating platelets substantially regulate vascular complications, including stroke, and share striking similarities with PD neurons. Although structural alterations in platelets are well-documented in PD, their functional parameters remain unclear. This study aimed to investigate the functional abnormalities in platelets associated with PD by evaluating key functional aspects such as adhesion, activation, secretion, aggregation, and clot retraction. To achieve this, we treated human blood platelets with 6-hydroxydopamine or 6-OHDA, that selectively destroys dopaminergic neurons, thereby creating an in vitro experimental model that closely resembles the pathogenic environment in PD, and examine its impact on platelet functions. In our study, platelet adhesion was assessed and further evaluated by a microplate reader, activation and secretion by a flow cytometer, aggregation by aggregometer, and clot retraction by Sonoclot. Phase-contrast and confocal microscopic studies further verified the results from the above experiments. Our findings showed that 6-OHDA treatment significantly inhibited thrombin (a platelet agonist)-induced functions, including adhesion, activation, aggregation, secretion, and clot retraction in human-washed platelets. In summary, this research provides pioneering evidence that 6-OHDA induces abnormal platelet functions, shedding light on the previously unexplored processes by which 6-OHDA affects platelet activity.

Instant clot forming and antibacterial wound dressings: Achieving hemostasis in trauma injuries with S-nitroso-N-acetylpenicillamine-tranexamic acid-propolis formulation

Wound infection and excessive blood loss are the two major challenges associated with trauma injuries that account for 10% of annual deaths in the United States. Nitric oxide (NO) is a gasotransmitter cell signaling molecule that plays a crucial role in the natural wound healing process due to its antibacterial, anti-inflammatory, cell proliferation, and tissue remodeling abilities. Tranexamic acid (TXA), a prothrombotic agent, has been used topically and systemically to control blood loss in reported cases of epistaxis and combat-related trauma injuries. Its properties could be incorporated in wound dressings to induce immediate clot formation, which is a key factor in controlling excessive blood loss. This study introduces a novel, instant clot-forming NO-releasing dressing, and fabricated using a strategic bi-layer configuration. The layer adjacent to the wound was designed with TXA suspended on a resinous bed of propolis, which is a natural bioadhesive possessing antibacterial and anti-inflammatory properties. The base layer, located furthest away from the wound, has an NO donor, S-nitroso-N-acetylpenicillamine (SNAP), embedded in a polymeric bed of Carbosil®, a copolymer of polycarbonate urethane and silicone. Propolis was integrated with a uniform layer of TXA in variable concentrations: 2.5, 5.0, and 7.5 vol % of propolis. This design of the TXA-SNAP-propolis (T-SP) wound dressing allows TXA to form a more stable clot by preventing the lysis of fibrin. The lactate dehydrogenase-based platelet adhesion assay showed an increase in fibrin activation with 7.5% T-SP as compared with control within the first 15 min of its application. A scanning electron microscope (SEM) confirmed the presence of a dense fibrin network stabilizing the clot for fabricated dressing. The antibacterial activity of NO and propolis resulted in a 98.9 ± 1% and 99.4 ± 1% reduction in the colony-forming unit of Staphylococcus aureus and multidrug-resistant Acinetobacter baumannii, respectively, which puts forward the fabricated dressing as an emergency first aid for traumatic injuries, preventing excessive blood loss and soil-borne infections.

A Biologic and Physical Characterization of an Injectable Amniotic Membrane Designed for Treating Diabetic Foot Ulcers

INTRODUCTION

Globally, the health and quality of life of millions of people are negatively affected by diabetic foot ulcers (DFUs). To treat these chronic wounds, a novel injectable drug for closing DFUs composed of micronized amniotic membrane was developed. This new therapeutic drug for wound repair expands on traditional allograft therapies by allowing extracellular matrix proteins, growth factors, and cytokines to reach wound anatomies in DFUs that are difficult to treat. The aim of this study was to evaluate the components of the injectable drug.

METHODS

Liquid chromatography with tandem mass spectrometry and a Quantibody® human cytokine array were conducted to identify and characterize growth factors and proteins known to contribute to wound healing. In addition, hyaluronic acid was quantified and compared between the injectable and human amniotic fluid using a hyaluronan enzyme-linked immunosorbent assay. Cell proliferation, migration, angiogenesis, and viability were evaluated to assess the performance of the novel injectable in vitro. The rheometric properties of the product were evaluated by assessing it pre- and post-injection through a 22-gauge needle to measure the viscosity using a shear- and temperature-dependent viscosity protocol.

RESULTS

Liquid chromatography with tandem mass spectrometry and Quantibody® human cytokine array revealed growth factors and proteins imperative for wound healing. The quantified hyaluronic acid was compared between the injectable and human amniotic fluid, resulting in a statistically significant difference, with higher protein concentrations found in the injectable. In vitro qualitative and quantitative analysis confirmed an increase in cell viability, proliferation, and migration when treated with the drug. An evaluation of the rheometric properties of the injectable drug after passing through a 22-gauge cannula presented no alterations to the biologic drug.

CONCLUSIONS

Collectively, these data present the potential of a novel injectable drug for the treatment of DFUs.

Exosome-based cell therapy for diabetic foot ulcers: Present and prospect

Diabetic foot ulcers (DFUs) represent a serious complication of diabetes with high incidence, requiring intensive treatment, prolonged hospitalization, and high costs. It poses a severe threat to the patient's life, resulting in substantial burdens on patient and healthcare system. However, the therapy of DFUs remains challenging. Therefore, exploring cell-free therapies for DFUs is both critical and urgent. Exosomes, as crucial mediators of intercellular communication, have been demonstrated potentially effective in anti-inflammation, angiogenesis, cell proliferation and migration, and collagen deposition. These functions have been proven beneficial in all stages of diabetic wound healing. This review aims to summarize the role and mechanisms of exosomes from diverse cellular sources in diabetic wound healing research. In addition, we elaborate on the challenges for clinical application, discuss the advantages of membrane vesicles as exosome mimics in wound healing, and present the therapeutic potential of exosomes and their mimetic vesicles for future clinical applications.

Polyphenols in wound healing: unlocking prospects with clinical applications

Wound healing is a multifaceted, complex process that factors like aging, metabolic diseases, and infections may influence. The potentiality of polyphenols, natural compounds, has shown anti-inflammatory and antimicrobial properties in promoting wound healing and their potential applications in wound management. The studies reviewed indicate that polyphenols have multiple mechanisms that promote wound healing. This involves enhancing antioxidant defenses, reducing oxidative stress, modulating inflammatory responses, improving healing times, reducing infection rates, and enhancing tissue regeneration in clinical trials and in vivo and in vitro studies. Polyphenols have been proven to be effective in managing hard-to-heal wounds, especially in diabetic and elderly populations. Polyphenols have shown significant benefits in promoting angiogenesis and stimulating collagen synthesis. Polyphenol treatment has been demonstrated to have therapeutic effects in wound healing and chronic wound management. Their ability to regulate key healing processes makes them suitable for new wound care products and treatments. Future research should enhance formulations and delivery methods to optimize polyphenols' bioavailability and therapeutic efficacy in wound management approaches.

Investigation of Tannic Acid Crosslinked PVA/PEI-Based Hydrogels as Potential Wound Dressings with Self-Healing and High Antibacterial Properties

This study developed hydrogels containing different ratios of TA using polyvinyl alcohol (PVA) and polyethyleneimine (PEI) polymers crosslinked with tannic acid (TA) for the treatment of burn wounds. Various tests, such as scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), swelling, moisture retention, contact angle, tensile strength, the scratch test, antibacterial activity and the in vitro drug-release test, were applied to characterize the developed hydrogels. Additionally, the hydrogels were examined for cytotoxic properties and cell viability with the WST-1 test. TA improved both the self-healing properties of the hydrogels and showed antibacterial activity, while the added gentamicin (GEN) further increased the antibacterial activities of the hydrogels. The hydrogels exhibited good hydrophilic properties and high swelling capacity, moisture retention, and excellent antibacterial activity, especially to S. aureus. In addition, the swelling and drug-release kinetics of hydrogels were investigated, and while swelling of hydrogels obeyed the pseudo-second-order modeling, the drug release occurred in a diffusion-controlled manner according to the Higuchi and Korsmeyer-Peppas models. These results show that PVA/PEI-based hydrogels have promising potential for wound dressings with increased mechanical strength, swelling, moisture retention, self-healing, and antibacterial properties.

The Well-Forgotten Old: Platelet-Rich Plasma in Modern Anti-Aging Therapy

Currently, approaches to personalized medicine are actively developing. For example, the use of platelet-rich plasma (PRP) is actively growing every year. As a result of activation, platelets release a wide range of growth factors, cytokines, chemokines, and angiogenic factors, after which these molecules regulate chemotaxis, inflammation, and vasomotor function and play a crucial role in restoring the integrity of damaged vascular walls, angiogenesis, and tissue regeneration. Due to these characteristics, PRP has a wide potential in regenerative medicine and gerontology. PRP products are actively used not only in esthetic medicine but also to stimulate tissue regeneration and relieve chronic inflammation. PRP therapy has a number of advantages, but the controversial results of clinical studies, a lack of standardization of the sample preparation of the material, and insufficient objective data on the evaluation of efficacy do not allow us to unambiguously look at the use of PRP for therapeutic purposes. In this review, we will examine the current clinical efficacy of PRP-based products and analyze the contribution of PRP in the therapy of diseases associated with aging.

Immunity and Coagulation in COVID-19

Discovered in late 2019, the SARS-CoV-2 coronavirus has caused the largest pandemic of the 21st century, claiming more than seven million lives. In most cases, the COVID-19 disease caused by the SARS-CoV-2 virus is relatively mild and affects only the upper respiratory tract; it most often manifests itself with fever, chills, cough, and sore throat, but also has less-common mild symptoms. In most cases, patients do not require hospitalization, and fully recover. However, in some cases, infection with the SARS-CoV-2 virus leads to the development of a severe form of COVID-19, which is characterized by the development of life-threatening complications affecting not only the lungs, but also other organs and systems. In particular, various forms of thrombotic complications are common among patients with a severe form of COVID-19. The mechanisms for the development of thrombotic complications in COVID-19 remain unclear. Accumulated data indicate that the pathogenesis of severe COVID-19 is based on disruptions in the functioning of various innate immune systems. The key role in the primary response to a viral infection is assigned to two systems. These are the pattern recognition receptors, primarily members of the toll-like receptor (TLR) family, and the complement system. Both systems are the first to engage in the fight against the virus and launch a whole range of mechanisms aimed at its rapid elimination. Normally, their joint activity leads to the destruction of the pathogen and recovery. However, disruptions in the functioning of these innate immune systems in COVID-19 can cause the development of an excessive inflammatory response that is dangerous for the body. In turn, excessive inflammation entails activation of and damage to the vascular endothelium, as well as the development of the hypercoagulable state observed in patients seriously ill with COVID-19. Activation of the endothelium and hypercoagulation lead to the development of thrombosis and, as a result, damage to organs and tissues. Immune-mediated thrombotic complications are termed "immunothrombosis". In this review, we discuss in detail the features of immunothrombosis associated with SARS-CoV-2 infection and its potential underlying mechanisms.

A Systematic Review on Biochemical Perspectives on Natural Products in Wound Healing: Exploring Phytochemicals in Tissue Repair and Scar Prevention

Wound healing is a critical process in tissue repair following injury, and traditional herbal therapies have long been utilized to facilitate this process. This review delves into the mechanistic understanding of the significant contribution of pharmacologically demonstrated natural products in wound healing. Natural products, often perceived as complex yet safely consumed compared to synthetic chemicals, play a crucial role in enhancing the wound-healing process. Drawing upon a comprehensive search strategy utilizing databases such as PubMed, Scopus, Web of Science, and Google Scholar, this review synthesizes evidence on the role of natural products in wound healing. While the exact pharmacological mechanisms of secondary metabolites in wound healing remain to be fully elucidated, compounds from alkaloids, phenols, terpenes, and other sources are explored here to delineate their specific roles in wound repair. Each phytochemical group exerts distinct actions in tissue repair, with some displaying multifaceted roles in various pathways, potentially enhancing their therapeutic value, supported by reported safety profiles. Additionally, these compounds exhibit promise in the prevention of keloids and scars. Their potential alongside economic feasibility may propel them towards pharmaceutical product development. Several isolated compounds, including chlorogenic acid, thymol, and eugenol from natural sources, are undergoing investigation in clinical trials, with many reaching advanced stages. This review provides mechanistic insights into the significant role of pharmacologically demonstrated natural products in wound healing processes.

Dissecting the roles of dynamin and clathrin in platelet pinocytosis

Platelets endocytose many molecules from their environment. However, this process of pinocytosis in platelets is poorly understood. Key endocytic regulators such as dynamin, clathrin, CDC42 and Arf6 are expressed in platelets but their roles in pinocytosis is not known. Stimulated platelets form two subpopulations of pro-aggregatory and procoagulant platelets. The effect of stimulation on pinocytosis is also poorly understood. In this study, washed human platelets were treated with a range of endocytosis inhibitors and stimulated using different activators. The rate of pinocytosis was assessed using pHrodo green, a pH-sensitive 10 kDa dextran. In unstimulated platelets, pHrodo fluorescence increased over time and accumulated as intracellular puncta indicating constituently active pinocytosis. Stimulated platelets (both pro-aggregatory and procoagulant) had an elevated pinocytosis rate compared to unstimulated platelets. Dynamin inhibition blocked pinocytosis in unstimulated, pro-aggregatory and procoagulant platelets indicating that most platelet pinocytosis is dynamin dependent. Although pinocytosis was clathrin-independent in unstimulated and procoagulant populations, clathrin partially contributed to pinocytosis in pro-aggregatory platelets.

Insight into hemostatic performance and mechanism of natural mixed-dimensional Attapulgite clay

Clay minerals have attracted wide attention as biomedical materials due to the unique crystal structure, abundant morphology and good biocompatibility. However, the relevant studies on the abundant natural mixed clay deposits were scarcely reported. Herein, the hemostatic performance of natural mixed-dimensional attapulgite clay (MDAPT) composed of one-dimensional attapulgite and multiple two-dimensional clay were systematically investigated based on the structural evolution using oxalic acid for different time. The results of hemostatic evaluation showed that MDAPT leached by oxalic acid with 1 h presented the shortest clotting time (134 ± 12.17 s), a 15.09 % and 41.74 % reduction of relative hemoglobin absorbance at 180 s and 120 s when compared with the control group, respectively, and an increase of 19.45 % of the blood clotting index in vitro, as well as MDAPT obtained the shortest bleeding time (158.5 ± 6.9 s), nearly 66 % and 31 % reduction blood loss as compared to the blank group and the YNBY group in vivo. This improvement was primarily ascribed to the synergistic effect of lamellar non-expandable illite, and nano rod-like attapulgite. Furthermore, the rapid hemostasis of MDAPT was also due to the joint effect of superhydrophobic property toward blood, minimizing blood loss, surface negative charge, metal ions from MDAPT structural skeleton, promoting an average increase of 21 % for platelet activation. The results suggested that MDAPT could be served as a promising efficient inorganic hemostatic materials, which provided a feasible strategy to realize the high-valued utilization of natural mixed clay resources.

Quantitative protein mass spectrometry for multiplex measurement of coagulation and fibrinolytic proteins towards clinical application: What, why and how?

Plasma proteins involved in coagulation and fibrinolysis are essential to hemostasis. Consequently, their circulating levels and functionality are critical in bleeding and thrombosis development. Well-established laboratory tests to assess these are available; however, said tests do not allow high multiplicity, require large volumes of plasma and are often costly. A novel technology to quantify plasma proteins is quantitative protein mass spectrometry (QPMS). Aided by stable isotope-labeled internal standards a large number of proteins can be quantified in one single analytical run requiring <30 μL of plasma. This provides an opportunity to improve insight in the etiology and prognosis of bleeding and thrombotic disorders, in which the balance between different proteins plays a crucial role. This manuscript aims to give an overview of the QPMS potential applications in thrombosis and hemostasis research (quantifying the 38 proteins assigned to coagulation and fibrinolysis by the KEGG database), but also to explore the potential and hurdles if designed for clinical practice. Advantages and limitations of QPMS are described and strategies for improved analysis are proposed, using as an example the test requirements for antithrombin. Application of this technology in the future could represent a step towards individualized patient care.

Evidence for platelet-derived transforming growth factor β1 as an early inducer of liver regeneration after hepatectomy in mice

Platelets play a crucial role in tissue regeneration, and their involvement in liver regeneration is well-established. However, the specific contribution of platelet-derived Transforming Growth Factor Beta 1 (TGFβ1) to liver regeneration remains unexplored. This study investigated the role of platelet-derived TGFβ1 in initiating liver regeneration following 2/3 liver resection. Using platelet-specific TGFβ1 knockout (Plt.TGFβ1 KO) mice and wild-type littermates (Plt.TGFβ1 WT) as controls, the study assessed circulating levels and hepatic gene expression of TGFβ1, Platelet Factor 4 (PF4), and Thrombopoietin (TPO) at early time points post-hepatectomy (post-PHx). Hepatocyte proliferation was quantified through Ki67 staining and PCNA expression in total liver lysates at various intervals, and phosphohistone-H3 (PHH3) staining was employed to mark mitotic cells. Circulating levels of hepatic mitogens, Hepatocyte Growth Factor (HGF), and Interleukin-6 (IL6) were also assessed. Results revealed that platelet-TGFβ1 deficiency significantly reduced total plasma TGFβ1 levels at 5 h post-PHx in Plt.TGFβ1 KO mice compared to controls. While circulating PF4 levels, liver platelet recruitment and activation appeared normal at early time points, Plt.TGFβ1 KO mice showed more stable circulating platelet numbers with higher numbers at 48 h post-PHx. Notably, hepatocyte proliferation was significantly reduced in Plt.TGFβ1 KO mice. The results show that a lack of TGFβ1 in platelets leads to an unbalanced expression of IL6 in the liver and to strongly increased HGF levels 48 h after liver resection, and yet liver regeneration remains reduced. The study identifies platelet-TGFβ1 as a regulator of hepatocyte proliferation and platelet homeostasis in the early stages of liver regeneration.

A study of scarless wound healing through programmed inflammation, proliferation and maturation using a redox balancing nanogel

In the study, we have shown the efficacy of an indigenously developed redox balancing chitosan gel with impregnated citrate capped Mn3O4 nanoparticles (nanogel). Application of the nanogel on a wound of preclinical mice model shows role of various signaling molecules and growth factors, and involvement of reactive oxygen species (ROS) at every stage, namely hemostasis, inflammation, and proliferation leading to complete maturation for the scarless wound healing. While in vitro characterization of nanogel using SEM, EDAX, and optical spectroscopy reveals pH regulated redox buffering capacity, in vivo preclinical studies on Swiss albino involving IL-12, IFN-γ, and α-SMA signaling molecules and detailed histopathological investigation and angiogenesis on every stage elucidate role of redox buffering for the complete wound healing process.

Platelets in Thrombosis and Atherosclerosis: A Double-Edged Sword

This review focuses on the dual role of platelets in atherosclerosis and thrombosis, exploring their involvement in inflammation, angiogenesis, and plaque formation, as well as their hemostatic and prothrombotic functions. Beyond their thrombotic functions, platelets engage in complex interactions with diverse cell types, influencing disease resolution and progression. The contribution of platelet degranulation helps in the formation of atheromatous plaque, whereas the reciprocal interaction with monocytes adds complexity. Alterations in platelet membrane receptors and signaling cascades contribute to advanced atherosclerosis, culminating in atherothrombotic events. Understanding these multifaceted roles of platelets will lead to the development of targeted antiplatelet strategies for effective cardiovascular disease prevention and treatment. Understanding platelet functions in atherosclerosis and atherothrombosis at different stages of disease will be critical for designing targeted treatments and medications to prevent or cure the disease Through this understanding, platelets can be targeted at specific times in the atherosclerosis process, possibly preventing the development of atherothrombosis.

Mechanisms and applications of the regenerative capacity of platelets-based therapy in knee osteoarthritis

Osteoarthritis (OA) is the most prevalent joint disease in the elderly population and its substantial morbidity and disability impose a heavy economic burden on patients and society. Knee osteoarthritis (KOA) is the most common subtype of OA, which is characterized by damage to progressive articular cartilage, synovitis, and subchondral bone sclerosis. Most current treatments for OA are palliative, primarily aim at symptom management, and do not prevent the progression of the disease or restore degraded cartilage. The activation of α-granules in platelets releases various growth factors that are involved in multiple stages of tissue repair, suggesting potential for disease modification. In recent years, platelet-based therapies, such as platelet-rich plasma, platelet-rich fibrin, and platelet lysates, have emerged as promising regenerative treatments for KOA, but their related effects and mechanisms are still unclear. Therefore, this review aims to summarize the biological characteristics and functions of platelets, classify the products of platelet-based therapy and related preparation methods. Moreover, we summarize the basic research of platelet-based regeneration strategies for KOA and discuss the cellular effects and molecular mechanisms. Further, we describe the general clinical application of platelet-based therapy in the treatment of KOA and the results of the meta-analysis of randomized controlled trials.

Inhibiting the P2Y12 Receptor in Megakaryocytes and Platelets Suppresses Interferon-Associated Responses

The authors investigated the impact of antiplatelet therapy on the megakaryocyte (MK) and platelet transcriptome. RNA-sequencing was performed on MKs treated with aspirin or P2Y12 inhibitor, platelets from healthy volunteers receiving aspirin or P2Y12 inhibition, and platelets from patients with systemic lupus erythematosus (SLE). P2Y12 inhibition reduced gene expression and inflammatory pathways in MKs and platelets. In SLE, the interferon (IFN) pathway was elevated. In vitro experiments demonstrated the role of P2Y12 inhibition in reducing IFNα-induced platelet-leukocyte interactions and IFN signaling pathways. These results suggest that P2Y12 inhibition may have therapeutic potential for proinflammatory and autoimmune conditions like SLE.

Platelets at the intersection of inflammation and coagulation in the APC-mediated response to myocardial ischemia/reperfusion injury

Thromboinflammation is a complex pathology associated with inflammation and coagulation. In cases of cardiovascular disease, in particular ischemia-reperfusion injury, thromboinflammation is a common complication. Increased understanding of thromboinflammation depends on an improved concept of the mechanisms of cells and proteins at the axis of coagulation and inflammation. Among these elements are activated protein C and platelets. This review summarizes the complex interactions of activated protein C and platelets regulating thromboinflammation in cardiovascular disease. By unraveling the pathways of platelets and APC in the inflammatory and coagulation cascades, this review summarizes the role of these vital mediators in the development and perpetuation of heart disease and the thromboinflammation-driven complications of cardiovascular disease. Furthermore, this review emphasizes the significance of the counteracting effects of platelets and APC and their combined role in disease states.

Advancements and Challenges of Nanostructured Lipid Carriers for Wound Healing Applications

The current treatments for wound healing still exhibit drawbacks due to limited availability at the action sites, susceptibility to degradation, and immediate drug release, all of which are detrimental in chronic conditions. Nano-modification strategies, offering various advantages that can enhance the physicochemical properties of drugs, have been employed in efforts to maximize the efficacy of wound healing medications. Nowadays, nanostructured lipid carriers (NLCs) provide drug delivery capabilities that can safeguard active compounds from environmental influences and enable controlled release profiles. Consequently, NLCs are considered an alternative therapy to address the challenges encountered in wound treatment. This review delves into the application of NLCs in drug delivery for wound healing, encompassing discussions on their composition, preparation methods, and their impact on treatment effectiveness. The modification of drugs into the NLC model can be facilitated using relatively straightforward technologies such as pressure-based processes, emulsification techniques, solvent utilization methods, or phase inversion. Moreover, NLC production with minimal material compositions can accommodate both single and combination drug delivery. Through in vitro, in vivo, and clinical studies, it has been substantiated that NLCs can enhance the therapeutic potential of various drug types in wound healing treatments. NLCs enhance efficacy by reducing the active substance particle size, increasing solubility and bioavailability, and prolonging drug release, ensuring sustained dosage at the wound site for chronic wounds. In summary, NLCs represent an effective nanocarrier system for optimizing the bioavailability of active pharmacological ingredients in the context of wound healing.

Cellular and molecular mechanisms of skin wound healing

Wound healing is a complex process that involves the coordinated actions of many different tissues and cell lineages. It requires tight orchestration of cell migration, proliferation, matrix deposition and remodelling, alongside inflammation and angiogenesis. Whereas small skin wounds heal in days, larger injuries resulting from trauma, acute illness or major surgery can take several weeks to heal, generally leaving behind a fibrotic scar that can impact tissue function. Development of therapeutics to prevent scarring and successfully repair chronic wounds requires a fuller knowledge of the cellular and molecular mechanisms driving wound healing. In this Review, we discuss the current understanding of the different phases of wound healing, from clot formation through re-epithelialization, angiogenesis and subsequent scar deposition. We highlight the contribution of different cell types to skin repair, with emphasis on how both innate and adaptive immune cells in the wound inflammatory response influence classically studied wound cell lineages, including keratinocytes, fibroblasts and endothelial cells, but also some of the less-studied cell lineages such as adipocytes, melanocytes and cutaneous nerves. Finally, we discuss newer approaches and research directions that have the potential to further our understanding of the mechanisms underpinning tissue repair.

Revitalizing female fertility: platelet-rich plasma - hype or hope?

Platelet-rich plasma (PRP) has gained popularity as an experimental tool in regenerative medicine, with potential applications in reproductive medicine. This review will assess the existing literature on the role of PRP in female fertility enhancement, focusing on ovarian rejuvenation and increased endometrial thickness. PRP is being explored as a treatment for recurrent implantation failure, primary ovarian insufficiency and poor ovarian response. While the influence of PRP on endometrial thickness and implantation success is postulated, its effectiveness remains the subject of debate due to protocol variability and unclear patient selection criteria. This narrative review includes 36 articles published before December 2022, and highlights the lack of comprehensive molecular studies examining the impact of PRP on reproductive capacity. This review underscores the importance of standardizing PRP preparation protocols in reproductive medicine. However, challenges persist, and there is a need for well-planned randomized controlled trials and a deeper understanding of the patient population that would gain the greatest benefit from PRP treatment. Clarifying these aspects is crucial to improve outcomes for low-prognosis patients undergoing assisted reproductive technology.

Unleashing the biomimetic targeting potential of platelet-derived nanocarriers on atherosclerosis

Atherosclerosis, the primary mechanism underlying the development of many cardiovascular illnesses, continues to be one of the leading causes of mortality worldwide. Platelet (PLT), which are essential for maintaining body homeostasis, have been strongly linked to the onset of atherosclerosis at various stages due to their inherent tendency to bind to atherosclerotic lesions and show an affinity for plaques. Therefore, mimicking PLT's innate adhesive features may be necessary to effectively target plaques. PLT-derived nanocarriers have emerged as a promising biomimetic targeting strategy for treating atherosclerosis due to their numerous advantages. These advantages include excellent biocompatibility, minimal macrophage phagocytosis, prolonged circulation time, targeting capability for impaired vascular sites, and suitability as carriers for anti-atherosclerotic drugs. Herein, we discuss the role of PLT in atherogenesis and propose the design of nanocarriers based on PLT-membrane coating and PLT-derived vesicles. These nanocarriers can target multiple biological elements relevant to plaque development. The review also emphasizes the current challenges and future research directions for the effective utilization of PLT-derived nanocarriers in treating atherosclerosis.

Icaritin Sensitizes Thrombin- and TxA2-Induced Platelet Activation and Promotes Hemostasis via Enhancing PLCγ2-PKC Signaling Pathways

BACKGROUND

 Vascular injury results in uncontrollable hemorrhage in hemorrhagic diseases and excessive antithrombotic therapy. Safe and efficient hemostatic agents which can be orally administered are urgently needed. Platelets play indispensable roles in hemostasis, but there is no drug exerting hemostatic effects through enhancing platelet function.

METHODS

 The regulatory effects of icaritin, a natural compound isolated from Herba Epimedii, on the dense granule release, thromboxane A2 (TxA2) synthesis, α-granule release, activation of integrin αIIbβ3, and aggregation of platelets induced by multiple agonists were investigated. The effects of icaritin on tail vein bleeding times of warfarin-treated mice were also evaluated. Furthermore, we investigated the underlying mechanisms by which icaritin exerted its pharmacological effects.

RESULTS

 Icaritin alone did not activate platelets, but significantly potentiated the dense granule release, α-granule release, activation of integrin αIIbβ3, and aggregation of platelets induced by thrombin and U46619. Icaritin also shortened tail vein bleeding times of mice treated with warfarin. In addition, phosphorylated proteome analysis, immunoblotting analysis, and pharmacological research revealed that icaritin sensitized the activation of phospholipase Cγ2 (PLCγ2)-protein kinase C (PKC) signaling pathways, which play important roles in platelet activation.

CONCLUSION

 Icaritin can sensitize platelet activation induced by thrombin and TxA2 through enhancing the activation of PLCγ2-PKC signaling pathways and promote hemostasis, and has potential to be developed into a novel orally deliverable therapeutic agent for hemorrhages.

Overcoming T Cell Exhaustion in Tumor Microenvironment via Immune Checkpoint Modulation with Nano-Delivery Systems for Enhanced Immunotherapy

Immune checkpoint blockade (ICB) therapy for tumors has arisen in growing interest. However, the low response rate of tumors to ICB is mainly attributed to the inhibitory infiltration of immune cells in the tumor microenvironment (TME). Despite the promising benefits of ICB, the therapeutic effects of antibodies are dependent on a high dose and long-term usage in the clinic, thereby leading to immune-related adverse effects. Accordingly, ICB combined with nano-delivery systems could be used to overcome T cell exhaustion, which reduces the side effects and the usage of antibodies with higher response rates in patients. In this review, the authors aim to overcome T cell exhaustion in TME via immune checkpoint modulation with nano-delivery systems for enhanced immunotherapy. Several strategies are summarized to combine ICB and nano-delivery systems to further enhance immunotherapy: a) expressing immune checkpoint on the surface of nano-delivery systems; b) loading immune checkpoint inhibitors into nano-delivery systems; c) loading gene-editing technology into nano-delivery systems; and d) nano-delivery systems mediated immune checkpoint modulation. Taken together, ICB combined with nano-delivery systems might be a promising strategy to overcome T cell exhaustion in TME for enhanced immunotherapy.

Platelet PD-L1 inhibits storage-induced apoptosis by sustaining activation of the AKT signalling pathway

Platelet apoptosis is irreversible under current storage conditions in blood banks. Studies have shown that programmed cell death ligand 1 (PD-L1) in tumour cells is required for neoplastic progression, tumour recurrence and metastasis by regulating apoptosis. However, whether PD-L1 is involved in storage-induced apoptosis in platelets remains poorly understood. In this study, we explored whether PD-L1 on platelets participated in the regulation of storage-induced apoptosis under blood bank conditions, as well as the underlying mechanism. Several apoptotic events in platelets from humans and PD-L1-knockout mice during storage under blood bank conditions were measured. The mechanism by which storage-induced apoptosis was regulated by platelet-intrinsic PD-L1 signalling was further investigated. Our results showed that PD-L1 in platelets progressively decreased. There was a strong negative correlation between platelet PD-L1 expression and the phosphatidylserine (PS) externalization rate and cleaved caspase-3 level and a positive correlation with anti-apoptosis protein Bcl-xl. Ex vivo, PD-L1-/- platelets stored at 22 °C showed rapid apoptosis via an intrinsic mitochondria-dependent pathway over time. Likewise, inhibiting PD-L1 signalling with BMS-1166 accelerated apoptosis by intrinsic mitochondria-dependent pathway. Coimmunoprecipitation analysis revealed that PD-L1 could bind AKT in platelets, and the binding capacity of both showed a progressive decrease with time. Finally, the decrease in PD-L1 expression levels during storage could be attributed to a complex process of progressive secretion. Therefore, platelet PD-L1 inhibits storage-induced apoptosis by sustaining activation of the AKT signalling pathway, which is expected to become a target for alleviating platelet storage lesions (PSLs) under current blood bank conditions.

Nanozyme-Incorporated Microneedles for the Treatment of Chronic Wounds

Acute wounds are converted to chronic wounds due to advanced age and diabetic complications. Nanozymes catalyze ROS production to kill bacteria without causing drug resistance, while microneedles (MNs) can break through the skin barrier to deliver drugs effectively. Nanozymes can be intergrateded into MNs delivery systems to improve painless drug delivery. It can also reduce the effective dose of drug sterilization while increasing delivery efficiency and effectively killing wounded bacteria while preventing drug resistance. This paper describes various types of metal nanozymes from previous studies and compares their mutual enhancement with nanozymes. The pooled results show that the MNs, through material innovation, are able to both penetrate the scab and deliver nanozymes and exert additional anti-inflammatory and bactericidal effects. The catalytic effect of some of the nanozymes can also accelerate the lysis of the MNs or create a cascade reaction against inflammation and infection. However, the issue of increased toxicity associated with skin penetration and clinical translation remains a challenge. This study reviews the latest published results and corresponding challenges associated with the use of MNs combined with nanozymes for the treatment of wounds, providing further information for future research.

Anticancer drugs and cardiotoxicity: the role of cardiomyocyte and non-cardiomyocyte cells

Cardiotoxicity can be defined as "chemically induced heart disease", which can occur with many different drug classes treating a range of diseases. It is the primary cause of drug attrition during pre-clinical development and withdrawal from the market. Drug induced cardiovascular toxicity can result from both functional effects with alteration of the contractile and electrical regulation in the heart and structural changes with morphological changes to cardiomyocytes and other cardiac cells. These adverse effects result in conditions such as arrhythmia or a more serious reduction in left ventricular ejection fraction (LVEF), which can lead to heart failure and death. Anticancer drugs can adversely affect cardiomyocyte function as well as cardiac fibroblasts and cardiac endothelial cells, interfering in autocrine and paracrine signalling between these cell types and ultimately altering cardiac cellular homeostasis. This review aims to highlight potential toxicity mechanisms involving cardiomyocytes and non-cardiomyocyte cells by first introducing the physiological roles of these cells within the myocardium and secondly, identifying the physiological pathways perturbed by anticancer drugs in these cells.

Evaluating the impact of type 2 diabetes mellitus on pulmonary vascular function and the development of pulmonary fibrosis

The increasing prevalence of type 2 diabetes mellitus (T2DM) is a significant worldwide health concern caused by sedentary lifestyles and unhealthy diets. Beyond glycemic control, T2DM impacts multiple organ systems, leading to various complications. While traditionally associated with cardiovascular and microvascular complications, emerging evidence indicates significant effects on pulmonary health. Pulmonary vascular dysfunction and fibrosis, characterized by alterations in vascular tone and excessive extracellular matrix deposition, are increasingly recognized in individuals with T2DM. The onset of T2DM is often preceded by prediabetes, an intermediate hyperglycemic state that is associated with increased diabetes and cardiovascular disease risk. This review explores the relationship between T2DM, pulmonary vascular dysfunction and pulmonary fibrosis, with a focus on potential links with prediabetes. Pulmonary vascular function, including the roles of nitric oxide (NO), prostacyclin (PGI2), endothelin-1 (ET-1), thromboxane A2 (TxA2) and thrombospondin-1 (THBS1), is discussed in the context of T2DM and prediabetes. Mechanisms linking T2DM to pulmonary fibrosis, such as oxidative stress, dysregulated fibrotic signaling, and chronic inflammation, are explained. The impact of prediabetes on pulmonary health, including endothelial dysfunction, oxidative stress, and dysregulated vasoactive mediators, is highlighted. Early detection and intervention during the prediabetic stage may reduce respiratory complications associated with T2DM, emphasizing the importance of management strategies targeting blood glucose regulation and vascular health. More research that looks into the mechanisms underlying pulmonary complications in T2DM and prediabetes is needed.

MXene-based composites in smart wound healing and dressings

MXenes, a class of two-dimensional materials, exhibit considerable potential in wound healing and dressing applications due to their distinctive attributes, including biocompatibility, expansive specific surface area, hydrophilicity, excellent electrical conductivity, unique mechanical properties, facile surface functionalization, and tunable band gaps. These materials serve as a foundation for the development of advanced wound healing materials, offering multifunctional nanoplatforms with theranostic capabilities. Key advantages of MXene-based materials in wound healing and dressings encompass potent antibacterial properties, hemostatic potential, pro-proliferative attributes, photothermal effects, and facilitation of cell growth. So far, different types of MXene-based materials have been introduced with improved features for wound healing and dressing applications. This review covers the recent advancements in MXene-based wound healing and dressings, with a focus on their contributions to tissue regeneration, infection control, anti-inflammation, photothermal effects, and targeted therapeutic delivery. We also discussed the constraints and prospects for the future application of these nanocomposites in the context of wound healing/dressings.