Bioxolography Using Diphenyliodonium Chloride and N‐Vinylpyrrolidone Enables Rapid High‐Resolution Volumetric 3D Printing of Spatially Encoded Living Matter

Light‐based volumetric bioprinting enables fabrication of cubic centimeter‐sized living materials with micrometer resolution in minutes. Xolography is a light sheet‐based volumetric printing technology that offers unprecedented volumetric generation rates and print resolutions for hard plastics. However, the limited solubility and reactivity of current dual‐color photoinitiators (DCPIs) in aqueous media have hindered their application for high‐resolution bioprinting of living matter. Here, we present a novel three‐component formulation that drastically improves photoreactivity and thereby enables high‐resolution, rapid, and cytocompatible Xolographic biofabrication of intricately architected yet mechanically robust living materials. To achieve this, various relevant additives are systematically explored, which revealed that diphenyliodonium chloride and N‐vinylpyrrolidone strongly enhance D‐mediated photoreactivity, as confirmed by dual‐color photo‐rheology. This enables Xolographic bioprinting of gelatin methacryloyl‐based bioresins, producing >1 cm3 constructs at ≈20 µm positive and 125 µm negative resolution within minutes. Multimaterial printing, molecular patterning, and grayscale‐mediated mechanical patterning are explored to programmably create intricate, biomimetic, and concentration‐controlled architectures. We demonstrate the Bioxolographic printing of various cell types, showing excellent cell viability, compatibility with long‐term culture, and ability for nascent protein deposition. These results position Bioxolography as a transformative platform for rapid, scalable, high‐resolution fabrication of functional living materials with encoded chemical and mechanical properties.