Fibrinogen 5.5mg/square cm / Thrombin 2units/square cm sealant matrix 4.8cm x 9.5cm

BackgroundFibrin is a biocompatible, angiogenic biomaterial widely used in soft tissue engineering, with outcomes influenced by scaffold formulation and design.AimThis systematic review evaluates how fibrin scaffold composition and design affect angiogenesis in in vitro and in vivo soft tissue models.MethodsPubMed, Scopus, and OVID were searched on 28/Oct/2024. A two-step screening process by three independent researchers identified original studies on fibrin scaffolds assessing endothelial formation and/or migration. Studies without experimental data or focused solely on grafts were excluded. Data on scaffold composition, manufactured objects, cell-embedding strategies, angiogenic outcomes, and a subset of muscle-specific studies were narratively synthesised. Risk of bias (RoB) and study quality were assessed using SYRCLE's RoB tool and a modified CAMARADES checklist.Results & discussionThe 81 studies highlight the impact of scaffold composition on angiogenic outcomes, with human-derived fibrinogen and pre-embedding cells consistently supporting successful outcomes. While tube and network formation outcomes typically aligned, endothelial migration exhibited different patterns. Thrombin often contributed positively, but crosslinker effects were less clear. Muscle-focused studies mainly used hydrogels and often included non-endothelial cells.ConclusionsFibrin scaffolds are highly relevant for soft tissue engineering, with outcomes influenced by formulation, fibrinogen source, and cell embedding. However, experimental design variability and lack of standardised reporting hinder reproducibility and clinical translation. To support future research, a minimum information checklist was created to promote consistent reporting, while aggregated success rates across design parameters could guide scaffold design.Registration & fundingPROSPERO [CRD42025612994] and OSF [10.17605/osf.io/nvfdj]. No funding body was directly involved.

Abstract licence: CC BY

Postpartum hemorrhage (PPH) remains the leading cause of preventable maternal mortality despite standard interventions. Recent fibrinogen trials failed to improve outcomes, prompting interest in coagulation factor XIII (FXIII). FXIII functions as "molecular cement," cross-linking fibrin and stabilizing clots. During pregnancy, FXIII activity decreases 20%-30%, with further depletion during PPH. Observational studies show low antepartum FXIII predicts bleeding risk, while ex vivo supplementation restores clot firmness. The SWIFT trial (NCT06481995) represents the first randomized controlled trial evaluating early FXIII supplementation in PPH. Although implementation challenges are significant (diagnostic accessibility, thrombotic monitoring, supply constraints), even modest hemostatic improvements could substantially reduce maternal mortality.

Abstract licence: CC BY