Three-dimensional (3D) printing of decellularized extracellular matrix (ECM) has been achieved to ensure real physiological environments for tissue engineering. However, the limited source, biocompatibility, and biosafety of decellularized ECM are deficiencies in its large clinical use. Autogenous ECM is biocompatible, bioactive, and biosafe, making it an optimal choice for future clinical applications of 3D printing. Here, we developed a multi-level customized 3D printing (MLC-3DP) strategy applying autogenous bone matrix (Auto-BM). This MLC-3DP includes shape specificity (shape), material specificity (Auto-BM), and cell specificity (autogenous cells) for true patient-specific repairs. Auto-BM (skull flaps) is readily accessible for specific patients after craniectomy, providing sufficient autogenous materials for MLC-3DP. Under mild conditions of this strategy, human-scale 3D printed samples can be fabricated using bioactive micron-sized Auto-BM particles. Multi-level customized autogenous bones (MLC-Auto-Bones) are finally obtained by combining autogenous bone marrow-derived mesenchymal stem cells (Auto-BMSCs). With autogenous materials and cells, MLC-Auto-Bones are inherently biocompatible and biosafe, providing good bioactivity for osteogenesis. In this implant, Auto-BMSCs can spontaneously differentiate into osteoblasts in vitro without additional osteogenic factors. In critical-sized skull defect models in vivo (3 months), implants integrate tightly to the defects' margin, facilitate mineralization, and generate vascularized mature bone. This work provides not only feasibility for patient-specific implants for skull defects, but also potential patient-specific solutions for other similar clinical requirements.

中文翻译：

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用于颅骨组织工程中自体植入物的多层定制3D打印。

已实现脱细胞细胞外基质（ECM）的三维（3D）打印，以确保组织工程的真实生理环境。但是，脱细胞ECM的来源，生物相容性和生物安全性有限，在其大量临床应用中是不足的。自体ECM具有生物相容性，生物活性和生物安全性，使其成为3D打印未来临床应用的最佳选择。在这里，我们使用自体骨基质（Auto-BM）开发了多层次的定制3D打印（MLC-3DP）策略。该MLC-3DP包括形状特异性（形状），材料特异性（Auto-BM）和细胞特异性（自体细胞），可进行真正的患者特异性修复。颅骨切除术后，特定患者容易获得Auto-BM（颅骨皮瓣），为MLC-3DP提供了充足的自体材料。在此策略的温和条件下，可以使用具有生物活性的微米尺寸的Auto-BM颗粒来制造人规模的3D打印样品。通过结合自体骨髓来源的间充质干细胞（Auto-BMSCs），最终获得了多级定制的自体骨骼（MLC-Auto-Bones）。MLC-Auto-Bones具有自体材料和细胞，具有内在的生物相容性和生物安全性，可为成骨提供良好的生物活性。在这种植入物中，Auto-BMSCs可以在体外自发分化为成骨细胞，而无需其他成骨因子。在体内关键尺寸的颅骨缺损模型（3个月）中，植入物紧密整合到缺损的边缘，促进矿化并生成血管化的成熟骨骼。这项工作不仅为特定患者的颅骨缺损植入物提供了可行性，