Lim Khoon S, Schon Benjamin S, Mekhileri Naveen V, Brown Gabriella C J, Chia Catherine M, Prabakar Sujay, Hooper Gary J, Woodfield Tim B F
Christchurch Regenerative Medicine and Tissue Engineering (CReaTE) Group, Department of Orthopaedics Surgery and Musculoskeletal Medicine, University of Otago Christchurch, Christchurch 8011, New Zealand.
The MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6140, New Zealand.
ACS Biomater Sci Eng. 2016 Oct 10;2(10):1752-1762. doi: 10.1021/acsbiomaterials.6b00149. Epub 2016 Aug 12.
Oxygen inhibition is a phenomenon that directly impacts the print fidelity of 3D biofabricated and photopolymerized hydrogel constructs. It typically results in the undesirable physical collapse of fabricated constructs due to impaired cross-linking, and is an issue that generally remains unreported in the literature. In this study, we describe a systematic approach to minimizing oxygen inhibition in photopolymerized gelatin-methacryloyl (Gel-MA)-based hydrogel constructs, by comparing a new visible-light initiating system, Vis + ruthenium (Ru)/sodium persulfate (SPS) to more conventionally adopted ultraviolet (UV) + Irgacure 2959 system. For both systems, increasing photoinitiator concentration and light irradiation intensity successfully reduced oxygen inhibition. However, the UV + I2959 system was detrimental to cells at both high I2959 concentrations and UV light irradiation intensities. The Vis + Ru/SPS system yielded better cell cyto-compatibility, where encapsulated cells remained >85% viable even at high Ru/SPS concentrations and visible-light irradiation intensities for up to 21 days, further highlighting the potential of this system to biofabricate cell-laden constructs with high shape fidelity, cell viability, and metabolic activity.
氧抑制是一种直接影响3D生物制造和光聚合水凝胶构建体打印保真度的现象。它通常会由于交联受损而导致制造的构建体出现不良的物理塌陷，并且这是一个在文献中普遍未被报道的问题。在本研究中，我们描述了一种系统方法，通过比较一种新的可见光引发体系（可见光+钌（Ru）/过硫酸钾（SPS））与更传统采用的紫外光（UV）+光引发剂Irgacure 2959体系，来最小化基于光聚合明胶-甲基丙烯酰基（Gel-MA）的水凝胶构建体中的氧抑制。对于这两种体系，增加光引发剂浓度和光照射强度都成功降低了氧抑制。然而，UV+I2959体系在高I2959浓度和紫外光照射强度下对细胞都有损害。可见光+Ru/SPS体系产生了更好的细胞细胞相容性，即使在高Ru/SPS浓度和可见光照射强度下长达21天，封装的细胞仍保持>85%的活力，进一步突出了该体系用于生物制造具有高形状保真度、细胞活力和代谢活性的载细胞构建体的潜力。
