Laser direct write (LDW) is a promising three-dimensional (3D) printing technology for creating proteinaceous microstructures in which the proteins retain their original function, enabling the manufacture of complex biomimetic 3D microenvironments and versatile enhancement of medical microdevices. A photoactivator has commonly been used to date in the laser direct write of proteins to enhance the cross-linking process. However, incomplete conversion results in photoactivator molecules remaining trapped inside the protein microstructure, causing their gradual leaching and subsequent undesirable effect on biological applications. Here, we demonstrate the 3D fabrication of microstructures made of pure serum albumin protein using photoactivator-free fabrication, confirmed by Raman data. For the first time, acid-catalyzed hydrolysis of the created structures provides evidence that chemical cross-links are induced by exposure to femtosecond laser irradiation. The diversity of the biomaterial protein available for the precursors for LDW offers capability of the fabrication of complex biomimetic 3D microenvironments and biochip applications.

中文翻译：

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飞秒激光多光子交联技术对纯蛋白质微结构的三维印刷

激光直写（LDW）是一种有前途的三维（3D）打印技术，可用于创建蛋白质的微结构，使蛋白质保留其原始功能，从而能够制造复杂的仿生3D微环境并提高医疗微设备的通用性。迄今为止，光活化剂已普遍用于蛋白质的激光直接写入中，以增强交联过程。然而，不完全的转化导致光活化剂分子残留在蛋白质微结构内，导致它们逐渐浸出并随后对生物学应用产生不良影响。在这里，我们演示了使用无光活化剂制造的纯血清白蛋白制成的微结构的3D制造，已通过拉曼数据证实。首次，酸催化产生的结构的水解作用提供了证据，证明通过暴露于飞秒激光辐照会诱导化学交联。可用于LDW前体的生物材料蛋白质的多样性为制造复杂的仿生3D微环境和生物芯片应用提供了能力。