We present a handheld skin printer that enables the in situ formation of biomaterial and skin tissue sheets of different homogeneous and architected compositions. When manually positioned above a target surface, the compact instrument (weight <0.8 kg) conformally deposits a biomaterial or tissue sheet from a microfluidic cartridge. Consistent sheet formation is achieved by coordinating the flow rates at which bioink and cross-linker solution are delivered, with the speed at which a pair of rollers actively translate the cartridge along the surface. We demonstrate compatibility with dermal and epidermal cells embedded in ionically cross-linkable biomaterials (e.g., alginate), and enzymatically cross-linkable proteins (e.g., fibrin), as well as their mixtures with collagen type I and hyaluronic acid. Upon rapid crosslinking, biomaterial and skin cell-laden sheets of consistent thickness, width and composition were obtained. Sheets deposited onto horizontal, agarose-coated surfaces were used for physical and in vitro characterization. Proof-of-principle demonstrations for the in situ formation of biomaterial sheets in murine and porcine excisional wound models illustrate the capacity of depositing onto inclined and compliant wound surfaces that are subject to respiratory motion. We expect the presented work will enable the in situ delivery of a wide range of different cells, biomaterials, and tissue adhesives, as well as the in situ fabrication of spatially organized biomaterials, tissues, and biohybrid structures.

中文翻译：

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手持式皮肤打印机：原位形成平面生物材料和组织†

我们推出了一款手持式皮肤打印机，能够原位形成不同均匀和结构化成分的生物材料和皮肤组织片。当手动定位在目标表面上方时，紧凑型仪器（重量<0.8 kg）从微流体盒中保形地沉积生物材料或组织片。通过协调生物墨水和交联剂溶液的输送流速以及一对辊沿表面主动平移墨盒的速度，可以实现一致的片材形成。我们证明了与嵌入离子交联生物材料（例如藻酸盐）和酶交联蛋白质（例如纤维蛋白）中的真皮和表皮细胞以及它们与I型胶原和透明质酸的混合物的相容性。快速交联后，获得了厚度、宽度和成分一致的生物材料和充满皮肤细胞的片材。沉积在水平的琼脂糖涂层表面上的片材用于物理和体外表征。在鼠和猪切除伤口模型中原位形成生物材料片的原理验证演示说明了沉积到受呼吸运动影响的倾斜和顺应伤口表面的能力。我们期望所提出的工作将能够原位输送各种不同的细胞、生物材料和组织粘合剂，以及空间组织的生物材料、组织和生物混合结构的原位制造。