Platelet‐like particles reduce coagulopathy‐related and neuroinflammatory pathologies post‐experimental traumatic brain injury

Abstract Coagulopathy may occur following traumatic brain injury (TBI), thereby negatively affecting patient outcomes. Here, we investigate the use of platelet‐like particles (PLPs), poly(N‐isopropylacrylamide‐ co ‐acrylic‐acid) microgels conjugated with a fibrin‐specific antibody, to improve hemostasis post‐TBI. The objective of this study was to diminish coagulopathy in a mouse TBI model (controlled cortical impact) via PLP treatment, and subsequently decrease blood–brain barrier (BBB) permeability and neuroinflammation. Following an acute intravenous injection of PLPs post‐TBI, we analyzed BBB permeability, ex vivo coagulation parameters, and neuroinflammation at 24 hr and 7 days post‐TBI. Both PLP‐treatment and control particle‐treatment had significantly decreased BBB permeability and improved clot structure 24 hr post‐injury. Additionally, no significant change in tissue sparing was observed between 24 hr and 7 days for PLP‐treated cohorts compared to that observed in untreated cohorts. Only PLP‐treatment resulted in significant reduction of astrocyte expression at 7 days and percent difference from 24 hr to 7 days. Finally, PLP‐treatment significantly reduced the percent difference from 24 hr to 7 days in microglia/macrophage density compared to the untreated control. These results suggest that PLP‐treatment addressed acute hypocoagulation and decreased BBB permeability followed by decreased neuroinflammation and fold‐change tissue loss by 7 days post‐injury. These promising results indicate that PLPs could be a potential therapeutic modality for TBI.