3D printing is known as a cost-effective technique that shows huge potential in fabrication of graft substitutes for bone tissue regeneration. However, the tradeoff between 3D printability, mechanical strength and bioactivity of the printed materials (i.e., inks) remains a challenge. In this work, we present a novel photocrosslinkable nanocomposite ink composed of tri-block poly (lactide-co-propylene glycol-co-lactide) dimethacrylate (P_mL_nDMA, m and n respectively represent the unit length of propylene glycol and lactide) and hydroxyethyl methacrylate (HEMA)-functionalized hydroxyapatite nanoparticles (nHAMA). The reactive HEMA-conjugated nHAMA, is designed to covalently crosslink with the surrounding polymer matrix to further increase the interfacial bonding between them. We find that the nHAMA can rapidly interact with P_mL_nDMA upon light exposure within 140 s and form an inorganic-organic co-crosslinked nanocomposite network, further enhancing the nanofiller-matrix interfacial compatibility. Notably, our nanocomposites possess significantly improved mechanical performances compared to the polymer, with compressive modulus increasing by nearly 10 times (from ⁓40 to ⁓400 MPa). Moreover, thanks to the low exothermic heat generation (<37 °C) during photocrosslinking, our nanocomposite ink enables facile encapsulation and long-term release of heat-labile biomolecules like bone morphogenic protein-2 (BMP-2). Furthermore, it demonstrates a readily tunable rheological property, wettability, degradation, and printability as a 3D bone scaffold. Together with its superior osteogenic ability both in vitro and in vivo, we envision that our nanocomposite ink holds great promise in 3D printing of bone grafts.

3D打印被认为是一种具有成本效益的技术，在制造用于骨组织再生的移植替代品方面显示出巨大的潜力。然而，在印刷材料（即油墨）的3D可印刷性，机械强度和生物活性之间进行权衡仍然是一个挑战。在这项工作中，我们提出的三嵌段聚组成的新颖光交联的纳米复合材料的油墨（丙交酯-共-丙烯乙二醇共-丙交酯）二甲基丙烯酸酯（P_米大号_ÑDMA，m和n分别表示丙二醇和丙交酯和甲基丙烯酸羟乙酯（HEMA）官能化的羟基磷灰石纳米粒子（nHAMA）的单位长度。反应性HEMA共轭nHAMA被设计为与周围的聚合物基质共价交联，以进一步增加它们之间的界面键合。我们发现nHAMA可以与P _m L _n快速相互作用DMA在140 s内曝光后形成无机-有机共交联的纳米复合材料网络，进一步增强了纳米填料-基质的界面相容性。值得注意的是，与聚合物相比，我们的纳米复合材料具有显着改善的机械性能，压缩模量提高了近10倍（从⁓40到⁓400MPa）。此外，由于在光交联过程中产生的放热低（<37°C），我们的纳米复合墨水能够轻松封装并长期释放热不稳定的生物分子，如骨形态发生蛋白2（BMP-2）。此外，它表现出易于调节的流变性质，润湿性，降解性和可印刷性，可作为3D骨支架。连同它的两个优异的成骨能力在体外和体内，我们设想我们的纳米复合材料墨水在3D植骨打印中具有广阔的前景。