Initiation efficiency and cytotoxicity of novel water-soluble two-photon photoinitiators for direct 3D microfabrication of hydrogels
作者:Zhiquan Li、Jan Torgersen、Aliasghar Ajami、Severin Mühleder、Xiaohua Qin、Wolfgang Husinsky、Wolfgang Holnthoner、Aleksandr Ovsianikov、Jürgen Stampfl、Robert Liska
DOI:10.1039/c3ra42918k
日期:——
The lack of efficient water-soluble two-photon absorption (TPA) photoinitiators has been a critical obstruction for three dimensional hydrogel microfabrications with high water load by two-photon induced polymerization (TPIP). In this paper, a series of cyclic benzylidene ketone-based two-photon initiators, containing carboxylic acid sodium salts to improve water solubility, were synthesized via classical aldol condensation reactions. The cytotoxicity of cyclopentanone-based photoinitiators is as low as that of the well-known biocompatible photoinitiator Irgacure 2959 as assessed in the dark with MG63 cell line. In z-scan measurement, the TPA cross sections of the investigated initiators are only moderate in water, while the TPA values for hydrophobic analogues measured in chloroform were much higher. All novel initiators exhibited broad processing windows in TPIP tests using hydrophilic photopolymers with up to 50 wt% of water. Impressively, microfabrication of hydrogels with excellent precision was possible at a writing speed as high as 100 mm s−1.
高效水溶性双光子吸收(TPA)光引发剂的缺乏,成为了通过双光子诱导聚合(TPIP)进行高水负载三维水凝胶微制造的一个关键障碍。本文合成了一系列基于环状苯亚甲酮的双光子引发剂,这些引发剂含有羧酸钠盐,以提高水溶性,合成过程采用经典的醛醇缩合反应。与著名的生物相容性光引发剂Irgacure 2959相比,环戊酮基光引发剂的细胞毒性在黑暗中与MG63细胞系的评估结果显示相当低。在z扫描测量中,所研究引发剂在水中的TPA截面仅为中等,而在氯仿中测得的疏水性类似物的TPA值则高得多。所有新型引发剂在使用水分含量高达50 wt%的亲水性光聚合物进行TPIP测试时,表现出宽广的加工窗口。令人印象深刻的是,以高达100 mm s−1的写入速度,水凝胶的微制造实现了卓越的精度。