Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
Disruptive Technology Laboratory, Massachusetts Eye and Ear and Schepens Eye Research Institute, Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
Acta Biomater. 2022 Jan 15;138:218-227. doi: 10.1016/j.actbio.2021.10.033. Epub 2021 Oct 28.
When ionizing irradiation interacts with a media, it can form reactive species that can react with the constituents of the system, leading to eradication of bioburden and sterilization of the tissue. Understanding the media's properties such as polarity is important to control and direct those reactive species to perform desired reactions. Using ethanol as a polarity modifier of water, we herein generated a series of media with varying relative polarities for electron beam (E-beam) irradiation of cornea at 25 kGy and studied how the irradiation media's polarity impacts properties of the cornea. After irradiation of corneal tissues, mechanical (tensile strength and modulus, elongation at break, and compression modulus), chemical, optical, structural, degradation, and biological properties of the corneal tissues were evaluated. Our study showed that irradiation in lower relative polarity media improved structural properties of the tissues yet reduced optical transmission; higher relative polarity reduced structural and optical properties of the cornea; and intermediate relative polarity (ethanol concentrations = 20-30% (v/v)) improved the structural properties, without compromising optical characteristics. Regardless of media polarity, irradiation did not negatively impact the biocompatibility of the corneal tissue. Our data shows that the absorbed ethanol can be flushed from the irradiated cornea to levels that are nontoxic to corneal and retinal cells. These findings suggest that the relative polarity of the irradiation media can be tuned to generate sterilized tissues, including corneal grafts, with engineered properties that are required for specific biomedical applications. STATEMENT OF SIGNIFICANCE: Extending the shelf-life of corneal tissue can improve general accessibility of cornea grafts for transplantation. Irradiation of donor corneas with E-beam is an emerging technology to sterilize the corneal tissues and enable their long-term storage at room temperature. Despite recent applications in clinical medicine, little is known about the effect of irradiation and preservation media's characteristics, such as polarity on the properties of irradiated corneas. Here, we have showed that the polarity of the media can be a valuable tool to change and control the properties of the irradiated tissue for transplantation.
当电离辐射与介质相互作用时，它可以形成活性物质，这些活性物质可以与系统的成分发生反应，从而消灭生物负荷并对组织进行灭菌。了解介质的性质，如极性，对于控制和引导这些活性物质进行所需的反应非常重要。我们使用乙醇作为水的极性调节剂，在此为角膜的电子束（E 射线）辐照生成了一系列具有不同相对极性的介质，研究了辐照介质的极性如何影响角膜的性质。在辐照角膜组织后，评估了角膜组织的机械（拉伸强度和模量、断裂伸长率和压缩模量）、化学、光学、结构、降解和生物学性质。我们的研究表明，在相对较低极性的介质中进行辐照可以改善组织的结构性质，但会降低光学透过率；较高的相对极性会降低角膜的结构和光学性质；而中间相对极性（乙醇浓度为 20-30%（v/v））则可以改善结构性质，而不会影响光学特性。无论介质的极性如何，辐照都不会对角膜组织的生物相容性产生负面影响。我们的数据表明，辐照后从角膜中冲洗出的吸收乙醇可以达到对角膜和视网膜细胞无毒的水平。这些发现表明，辐照介质的相对极性可以进行调整，以产生具有特定生物医学应用所需工程特性的已灭菌组织，包括角膜移植物。
延长角膜组织的保质期可以提高角膜移植物的普遍可及性，使其更容易用于移植。用电子束辐照供体角膜是一种新兴的技术，可以对角膜组织进行灭菌，并使其在室温下长期储存。尽管最近在临床医学中有应用，但对于辐照和保存介质的特性（如极性）对辐照角膜性质的影响知之甚少。在这里，我们表明，介质的极性可以成为改变和控制移植用辐照组织性质的有用工具。
