Bioprinting of live platelet-loaded nerve conduit using energy-dissipative hydrogel

Platelets show great promise for nerve repair due to their abundant release of growth factors. However, they often suffer from rapid activation-induced burst release of the cargo, making it challenging to develop long-acting platelet preparation. Here, we show a biosynthetic nerve conduit containing platelets with prolonged survival for peripheral nerve repair. This conduit was rapidly fabricated using a customized 3D printer by coating a platelet-loaded Pluronic F127 diacrylate hydrogel onto an electrospinning polycaprolactone conduit. The hydrogel can protect the platelets from stress-induced activation during deformation through its nanocolloid-based energy-dissipative centers, achieving a platelet survival rate of 34.7 % after 600 compression cycles. Platelets survived in this hydrogel for over 2 weeks, enabling the sustained release of bioactive cargo such as NGF and VEGF for more than 20 days. This conduit also had good mechanical properties, including compression and stretch resistance, to support surgical suturing and structural stability in vivo. Twelve weeks post-implantation, this conduit efficiently promoted nerve repair with functional outcomes by providing a growth factor-rich microenvironment, demonstrating potential clinical application.