Photothermal Ablation Blotting for Capillary-Scale Microvasculature Engineering.

Reconstruction of functional microvascular networks, particularly at the capillary scale, remains a critical bottleneck for the integration of tissue-engineered grafts with host tissues. Here, we report a photothermal ablation blotting (PAB) strategy for engineering perfusable, robust, and hierarchically branched microvascular network within a hydrogel matrix. This approach leverages bioresorbable photothermal fibers (PTF) that act as a sculpting template, enabling multiple diameters of controlled microchannel formation upon sequential near-infrared (NIR) and UV activation while simultaneously enhancing the mechanical toughness of the hydrogel via fiber reinforcement. The resulting photothermal microchannel hydrogel (PMH) supports efficient perfusion and cellular infiltration in vitro, and facilitates vascular integration and tissue remodeling in vivo through both rat subcutaneous and myocardial infarction (MI) models. This PAB platform offers a scalable and adaptable method for capillary-scale microvasculature engineering, with broad applicability across regenerative medicine and soft tissue reconstruction.