Vienna University of Technology, Institute of Materials Science and Engineering, Favoritenstrasse 9-11, 1040 Vienna, Austria.
J Biomed Opt. 2012 Oct;17(10):105008. doi: 10.1117/1.JBO.17.10.105008.
Hydrogels are polymeric materials with water contents similar to that of soft tissues. Due to their biomimetic properties, they have been extensively used in various biomedical applications including cell encapsulation for tissue engineering. The utilization of photopolymers provides a possibility for the temporal and spatial controlling of hydrogel cross-links. We produced three-dimensional (3-D) hydrogel scaffolds by means of the two-photon polymerization (2PP) technique. Using a highly efficient water-soluble initiator, photopolymers with up to 80 wt.% water were processed with high precision and reproducibility at a writing speed of 10 mm/s. The biocompatibility of the applied materials was verified using Caenorhabditis elegans as living test organisms. Furthermore, these living organisms were successfully embedded within a 200×200×35 μm³ hydrogel scaffold. As most biologic tissues exhibit a window of transparency at the wavelength of the applied femtosecond laser, it is suggested that 2PP is promising for an in situ approach. Our results demonstrate the feasibility of and potential for bio-fabricating 3-D tissue constructs in the micrometre-range via near-infrared lasers in direct contact with a living organism.
水凝胶是具有类似于软组织含水量的高分子材料。由于其仿生特性，它们已被广泛应用于各种生物医学应用中，包括组织工程中的细胞封装。光聚合物的利用为水凝胶交联的时空控制提供了可能性。我们通过双光子聚合（2PP）技术制备了三维（3-D）水凝胶支架。使用高效水溶性引发剂，以 10mm/s 的写入速度，可以高精度和可重复地处理高达 80wt.%水的光聚合物。通过使用秀丽隐杆线虫作为活体测试生物，验证了所应用材料的生物相容性。此外，这些活体生物成功地嵌入了 200×200×35μm³的水凝胶支架中。由于大多数生物组织在应用飞秒激光的波长处具有透明窗口，因此建议 2PP 具有用于原位方法的潜力。我们的结果证明了通过近红外激光与活体直接接触，在微尺度范围内通过生物制造 3-D 组织构建体的可行性和潜力。
