Shubin Andrew D, Felong Timothy J, Graunke Dean, Ovitt Catherine E, Benoit Danielle S W
1Department of Biomedical Engineering, University of Rochester, Rochester, New York.
2Center for Oral Biology, University of Rochester, Rochester, New York.
Tissue Eng Part A. 2015 Jun;21(11-12):1733-51. doi: 10.1089/ten.TEA.2014.0674. Epub 2015 Apr 17.
More than 40,000 patients are diagnosed with head and neck cancers annually in the United States with the vast majority receiving radiation therapy. Salivary glands are irreparably damaged by radiation therapy resulting in xerostomia, which severely affects patient quality of life. Cell-based therapies have shown some promise in mouse models of radiation-induced xerostomia, but they suffer from insufficient and inconsistent gland regeneration and accompanying secretory function. To aid in the development of regenerative therapies, poly(ethylene glycol) hydrogels were investigated for the encapsulation of primary submandibular gland (SMG) cells for tissue engineering applications. Different methods of hydrogel formation and cell preparation were examined to identify cytocompatible encapsulation conditions for SMG cells. Cell viability was much higher after thiol-ene polymerizations compared with conventional methacrylate polymerizations due to reduced membrane peroxidation and intracellular reactive oxygen species formation. In addition, the formation of multicellular microspheres before encapsulation maximized cell-cell contacts and increased viability of SMG cells over 14-day culture periods. Thiol-ene hydrogel-encapsulated microspheres also promoted SMG proliferation. Lineage tracing was employed to determine the cellular composition of hydrogel-encapsulated microspheres using markers for acinar (Mist1) and duct (Keratin5) cells. Our findings indicate that both acinar and duct cell phenotypes are present throughout the 14 day culture period. However, the acinar:duct cell ratios are reduced over time, likely due to duct cell proliferation. Altogether, permissive encapsulation methods for primary SMG cells have been identified that promote cell viability, proliferation, and maintenance of differentiated salivary gland cell phenotypes, which allows for translation of this approach for salivary gland tissue engineering applications.
在美国,每年有超过4万名患者被诊断患有头颈癌,绝大多数患者接受放射治疗。放射治疗会对唾液腺造成不可修复的损伤,导致口干症,严重影响患者的生活质量。基于细胞的疗法在辐射诱导的口干症小鼠模型中显示出了一些前景,但它们存在腺体再生不足且不一致以及伴随的分泌功能问题。为了辅助再生疗法的开发,研究了聚乙二醇水凝胶用于包裹下颌下腺(SMG)原代细胞以用于组织工程应用。研究了不同的水凝胶形成方法和细胞制备方法,以确定SMG细胞的细胞相容性包裹条件。与传统的甲基丙烯酸酯聚合相比,硫醇-烯聚合后细胞活力更高,这是由于膜过氧化和细胞内活性氧生成减少。此外,在包裹前形成多细胞微球可使细胞间接触最大化,并在14天的培养期内提高SMG细胞的活力。硫醇-烯水凝胶包裹的微球也促进了SMG的增殖。采用谱系追踪法,使用腺泡(Mist1)和导管(角蛋白5)细胞的标记物来确定水凝胶包裹微球的细胞组成。我们的研究结果表明,在整个14天的培养期内,腺泡和导管细胞表型均存在。然而,随着时间的推移,腺泡:导管细胞比例降低,可能是由于导管细胞增殖。总之,已经确定了用于原代SMG细胞的允许性包裹方法,这些方法可促进细胞活力、增殖以及维持分化的唾液腺细胞表型,这使得这种方法能够转化用于唾液腺组织工程应用。