Tranexamic acid for haemostasis and beyond: does dose matter?

Spatiotemporally Controlled Release of Etamsylate from Bioinspired Peptide-Functionalized Nanoparticles Arrests Bleeding Rapidly and Improves Clot Stability in a Rabbit Internal Hemorrhage Model

Achieving rapid clotting and clot stability are important unmet goals of clinical management of noncompressible hemorrhage. This study reports the development of a spatiotemporally controlled release system of an antihemorrhagic drug, etamsylate, in the management of internal hemorrhage. Gly-Arg-Gly-Asp-Ser (GRGDS) peptide-functionalized chitosan nanoparticles, with high affinity to bind with the GPIIa/IIIb receptor of activated platelets, were loaded with the drug etamsylate (etamsylate-loaded GRGDS peptide-functionalized chitosan nanoparticles; EGCSNP). Peptide conjugation was confirmed by LCMS, and the delivery system was characterized by DLS, SEM, XRD, and FTIR. In vitro study exhibited 90% drug release till 48 h fitting into the Weibull model. Plasma recalcification time and prothrombin time tests of GRGDS-functionalized nanoparticles proved that clot formation was 1.5 times faster than nonfunctionalized chitosan nanoparticles. The whole blood clotting time was increased by 2.5 times over clot formed under nonfunctionalized chitosan nanoparticles. Furthermore, the application of rheometric analysis revealed a 1.2 times stiffer clot over chitosan nanoparticles. In an in vivo liver laceration rabbit model, EGCSNP spatially localized at the internal injury site within 5 min of intravenous administration, and no rebleeding was recorded up to 3 h. The animals survived for 3 weeks after the injury, indicating the strong potential of the system for the management of noncompressible hemorrhage.

Tranexamic Acid Use in the Surgical Arena: A Narrative Review

INTRODUCTION

Tranexamic acid (TXA) is a potent antifibrinolytic drug that inhibits the activation of plasmin by plasminogen. While not a new medication, TXA has quickly gained traction across a variety of surgical subspecialties to prevent and treat bleeding. Knowledge on the use of this drug is essential for the modern surgeon to continue to provide excellent care to their patients.

METHODS

A comprehensive review of the PubMed database was conducted of articles published within the last 10 y (2014-2024) relating to TXA and its use in various surgical subspecialties. Seminal studies regarding the use of TXA older than 10 y were included from the author's archives.

RESULTS

Indications for TXA are not limited to trauma alone, and TXA is utilized across a variety of surgical subspecialties from neurosurgery to hepatic surgery to control hemorrhage. Overall, TXA is well tolerated with common dose-dependent adverse effects, including headache, nasal symptoms, dizziness, nausea, diarrhea, and fatigue. More severe adverse events are rare and easily mitigated by not exceeding a dose of 50 mg/kg.

CONCLUSIONS

The administration of TXA as an adjunct to treat trauma saves lives. The ability of TXA to induce seizures is dose dependent with identifiable risk factors, making this serious adverse effect predictable. As for the potential for TXA to cause thrombotic events, uncertainty remains. If this association is proven to be real, the risk will likely be small, since the use of TXA is still advantageous in most situations because of its efficacy for a more common concern, bleeding.

Unravelling the Antifibrinolytic Mechanism of Action of the 1,2,3-Triazole Derivatives

A new family of antifibrinolytic drugs has been recently discovered, combining a triazole moiety, an oxadiazolone, and a terminal amine. Two of the molecules of this family have shown activity that is greater than or similar to that of tranexamic acid (TXA), the current antifibrinolytic gold standard, which has been associated with several side effects and whose use is limited in patients with renal impairment. The aim of this work was to thoroughly examine the mechanism of action of the two ideal candidates of the 1,2,3-triazole family and compare them with TXA, to identify an antifibrinolytic alternative active at lower dosages. Specifically, the antifibrinolytic activity of the two compounds (1 and 5) and TXA was assessed in fibrinolytic isolated systems and in whole blood. Results revealed that despite having an activity pathway comparable to that of TXA, both compounds showed greater activity in blood. These differences could be attributed to a more stable ligand-target binding to the pocket of plasminogen for compounds 1 and 5, as suggested by molecular dynamic simulations. This work presents further evidence of the antifibrinolytic activity of the two best candidates of the 1,2,3-triazole family and paves the way for incorporating these molecules as new antifibrinolytic therapies.

A systematic review and meta-analysis of systematic and topical tranexamic acid administration in aesthetic plastic surgery

INTRODUCTION

Tranexamic acid has been widely used in plastic surgery. However, its efficacy has yet to be fully established. This meta-analysis aimed to determine its effectiveness in aesthetic plastic surgery.

METHODS

Following PRISMA guidelines, we conducted a meta-analysis of prospective randomised clinical trials that compared the effects of topical or systematic administration of tranexamic acid versus the control group in aesthetic plastic surgeries. The study was registered on the International Register of Systematic Reviews (PROSPERO) and is available online ( www.crd.york.uk/prospero , CRD42023492585).

RESULTS

Eleven studies encompassing 960 patients were included for the synthesis after critical evaluation. Systematic (MD - 18.05, 95% Cl, - 22.01, - 14.09, p < 0.00001) and topical (MD - 74.93, 95% Cl, - 88.79, - 61.07, p < 0.00001) administration of tranexamic acid reduced total blood loss. Topical tranexamic acid reduced drainage output (p < 0.0006).

CONCLUSION

Tranexamic acid reduced blood loss in aesthetic plastic surgery. More strictly defined RCTs, using high-quality methodology, are needed to evaluate the advantages and disadvantages of tranexamic acid in aesthetic plastic surgery.

Plasminogen degrades α-synuclein, Tau and TDP-43 and decreases dopaminergic neurodegeneration in mouse models of Parkinson's disease

Parkinson's disease (PD) is the second most frequently diagnosed neurodegenerative disease, and it is characterized by the intracellular and extracellular accumulation of α-synuclein (α-syn) and Tau, which are major components of cytosolic protein inclusions called Lewy bodies, in the brain. Currently, there is a lack of effective methods that preventing PD progression. It has been suggested that the plasminogen activation system, which is a major extracellular proteolysis system, is involved in PD pathogenesis. We investigated the functional roles of plasminogen in vitro in an okadaic acid-induced Tau hyperphosphorylation NSC34 cell model, ex vivo using brains from normal controls and methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice, and in vivo in a widely used MPTP-induced PD mouse model and an α-syn overexpression mouse model. The in vitro, ex vivo and in vivo results showed that the administered plasminogen crossed the blood‒brain barrier (BBB), entered cells, and migrated to the nucleus, increased plasmin activity intracellularly, bound to α-syn through lysine binding sites, significantly promoted α-syn, Tau and TDP-43 clearance intracellularly and even intranuclearly in the brain, decreased dopaminergic neurodegeneration and increased the tyrosine hydroxylase levels in the substantia nigra and striatum, and improved motor function in PD mouse models. These findings indicate that plasminogen plays a wide range of pivotal protective roles in PD and therefore may be a promising drug candidate for PD treatment.

Role of factor XIII in ischemic stroke: a key molecule promoting thrombus stabilization and resistance to lysis

BACKGROUND

Active coagulation factor XIII (FXIII) catalyzing crosslinking of fibrin and other hemostatic factors plays a key role in clot stability and lysis.

OBJECTIVES

To evaluate the effect of FXIII inhibition in a mouse model of ischemic stroke (IS) and the role of activated FXIII (FXIIIa) in clot formation and lysis in patients with IS.

METHODS

A ferric chloride IS murine model was performed before and after administration of a FXIIIa inhibitor (FXIIIinh). Thromboelastometry in human and mice blood was used to evaluate thrombus stiffness and lysis with FXIIIinh. FXIIIa-dependent fibrin crosslinking and lysis with fibrinolytic drugs (tissue plasminogen activator and tenecteplase) were studied on fibrin plates and on thrombi and clotted plasma of patients with IS. Finally, circulating and thrombus FXIIIa were measured in 85 patients with IS.

RESULTS

FXIIIinh administration before stroke induction reduced infarct size, α2-antiplasmin (α2AP) crosslinking, and local microthrombosis, improving motor coordination and fibrinolysis without intracranial bleeds (24 hours). Interestingly, FXIII blockade after stroke also reduced brain damage and neurologic deficit. Thromboelastometry in human/mice blood with FXIIIinh showed delayed clot formation, reduced clot firmness, and shortened tissue plasminogen activator lysis time. FXIIIa fibrin crosslinking increased fibrin density and lysis resistance, which increased further after α2AP addition. FXIIIinh enhanced ex vivo lysis in stroke thrombi and fibrin plates. In patients with IS, thrombus FXIII and α2AP were associated with inflammatory and hemostatic components, and plasma FXIIIa correlated with thrombus α2AP and fibrin.

CONCLUSION

Our results suggest a key role of FXIIIa in thrombus stabilization, α2AP crosslinking, and lysis resistance, with a protective effect of FXIIIinh in an IS experimental model.

The Roles of Fibrinolytic Factors in Bone Destruction Caused by Inflammation

Chronic inflammatory diseases, such as rheumatoid arthritis, spondyloarthritis, systemic lupus erythematosus, Crohn's disease, periodontitis, and carcinoma metastasis frequently result in bone destruction. Pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), IL-6, and IL-17 are known to influence bone loss by promoting the differentiation and activation of osteoclasts. Fibrinolytic factors, such as plasminogen (Plg), plasmin, urokinase-type plasminogen activator (uPA), its receptor (uPAR), tissue-type plasminogen activator (tPA), α2-antiplasmin (α2AP), and plasminogen activator inhibitor-1 (PAI-1) are expressed in osteoclasts and osteoblasts and are considered essential in maintaining bone homeostasis by regulating the functions of both osteoclasts and osteoblasts. Additionally, fibrinolytic factors are associated with the regulation of inflammation and the immune system. This review explores the roles of fibrinolytic factors in bone destruction caused by inflammation.