Tampere University of Technology, Department of Biomedical Engineering, PO Box 692, 33101 Tampere, Finland.
Biofabrication. 2011 Dec;3(4):045002. doi: 10.1088/1758-5082/3/4/045002. Epub 2011 Sep 9.
This study reports the pico- and femtosecond laser-induced photocrosslinking of protein microstructures. The capabilities of a picosecond Nd:YAG laser to promote multiphoton excited crosslinking of proteins were evaluated by fabricating 2D and 3D microstructures of avidin, bovine serum albumin (BSA) and biotinylated bovine serum albumin (bBSA). The multiphoton absorption-induced photocrosslinking of proteins was demonstrated here for the first time with a non-toxic biomolecule flavin mononucleotide (FMN) as the photosensitizer. Sub-micrometer and micrometer scale structures were fabricated from several different compositions of protein and photosensitizer by varying the average laser power and scanning speed in order to determine the optimal process parameters for efficient photocrosslinking. In addition, the retention of ligand-binding ability of the crosslinked protein structures was shown by fluorescence imaging of immobilized biotin or streptavidin conjugated fluorescence labels. The surface topography and the resolution of the protein patterns fabricated with the Nd:YAG laser were compared to the results obtained with a femtosecond Ti:Sapphire laser. Quite similar grain characteristics and comparable feature sizes were achieved with both laser sources, which demonstrates the utility of the low-cost Nd:YAG microlaser for direct laser writing of protein microstructures.
本研究报告了皮秒和飞秒激光诱导的蛋白质微结构光交联。通过制备亲和素、牛血清白蛋白（BSA）和生物素化牛血清白蛋白（bBSA）的 2D 和 3D 微结构，评估了皮秒 Nd：YAG 激光促进多光子激发交联蛋白质的能力。本文首次以无毒生物分子黄素单核苷酸（FMN）作为光增感剂，证明了蛋白质的多光子吸收诱导光交联。通过改变平均激光功率和扫描速度，从几种不同的蛋白质和光增感剂组成中制造出亚微米和微米级结构，以确定有效光交联的最佳工艺参数。此外，通过固定化生物素或链霉亲和素结合荧光标记的荧光成像，显示了交联蛋白质结构保留配体结合能力。将 Nd：YAG 激光制造的蛋白质图案的表面形貌和分辨率与飞秒钛宝石激光的结果进行了比较。两种激光源都实现了相当相似的晶粒特性和可比的特征尺寸，这证明了低成本 Nd：YAG 微激光器在蛋白质微结构的直接激光写入中的实用性。
