Construction of self-adaptive biomaterials surface with high blood compatibility

. The physiological extracellular matrix (ECM) exhibits self-adaptive and self-regulation merits in establishment, separation and maintenance of differentiated tissues and organs. The ECM is three-dimensional, non-cellular structure that is mainly composed of collagens, proteoglycans, glycoproteins, and smaller amounts of other proteins. Biomedical implant mimicking the physiological extracellular matrix (ECM) is a new strategy to modulate the cell microenvironment to improve implant integrity and longevity. Inspired by ECM, we constructed a bio-mimic ECM with a dual-layer nano-architecture on the implant surface to render the surface adaptive to inflammatory stimuli and remodelable possessing long-term anti-inflammatory and anti-thrombotic capability. The inner layer consisted of PCL-PEG-PCL/Au–heparin electrospun fibers encapsulated with indomethacin while the outer layer was composed of polyvinyl alcohol (PVA) and ROS-responsive polymer fibers (PBA). In response to acute inflammation after vascular injury, the outer layer reduced ROS rapidly by PBA degradation for inflammation suppression. The degraded outer layer facilitated inner layer reconstruction with enhanced hemocompatibility through the H-bond between PVA and PCL-PEG-PCL. Moreover, chronic inflammation was effectively depressed with the sustained release of indomethacin from the inner layer. The substantial enhancement of the functional integrity of implants and reduction of thrombotic and inflammatory complications with the self-adaptive ECM were demonstrated both in vitro and in vivo. Our work paves a new way to develop long-term antithrombotic and anti-inflammatory implants with self-adaption and self-regulation properties

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