Department of Bioengineering, University of Colorado Denver | Anschutz Medical Campus, Aurora, CO, United States of America.
Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, United States of America.
Biofabrication. 2022 Dec 19;15(1). doi: 10.1088/1758-5090/aca8cf.
Pulmonary arterial hypertension (PAH) is a progressive disease of the lung vasculature, characterized by elevated pulmonary blood pressure, remodeling of the pulmonary arteries, and ultimately right ventricular failure. Therapeutic interventions for PAH are limited in part by the lack ofscreening platforms that accurately reproduce dynamic arterial wall mechanical properties. Here we present a 3D-bioprinted model of the pulmonary arterial adventitia comprised of a phototunable poly(ethylene glycol) alpha methacrylate (PEG-αMA)-based hydrogel and primary human pulmonary artery adventitia fibroblasts (HPAAFs). This unique biomaterial emulates PAH pathogenesisthrough a two-step polymerization reaction. First, PEG-αMA macromer was crosslinked off-stoichiometry by 3D bioprinting an acidic bioink solution into a basic gelatin support bath initiating a base-catalyzed thiol-ene reaction with synthetic and biodegradable crosslinkers. Then, matrix stiffening was induced by photoinitiated homopolymerization of unreacted αMA end groups. A design of experiments approach produced a hydrogel platform that exhibited an initial elastic modulus () within the range of healthy pulmonary arterial tissue (= 4.7 ± 0.09 kPa) that was stiffened to the pathologic range of hypertensive tissue (= 12.8 ± 0.47 kPa) and supported cellular proliferation over time. A higher percentage of HPAAFs cultured in stiffened hydrogels expressed the fibrotic marker alpha-smooth muscle actin than cells in soft hydrogels (88 ± 2% versus 65 ± 4%). Likewise, a greater percentage of HPAAFs were positive for the proliferation marker 5-ethynyl-2'-deoxyuridine (EdU) in stiffened models (66 ± 6%) compared to soft (39 ± 6%). These results demonstrate that 3D-bioprinted, phototunable models of pulmonary artery adventitia are a tool that enable investigation of fibrotic pathogenesis.
肺动脉高压（PAH）是一种肺部血管的进行性疾病，其特征是肺动脉血压升高、肺动脉重塑，最终导致右心衰竭。PAH 的治疗干预在一定程度上受到缺乏能够准确再现动态动脉壁力学特性的筛选平台的限制。在这里，我们提出了一种由可光调控的聚乙二醇甲基丙烯酸酯（PEG-αMA）基水凝胶和原代人肺动脉外膜成纤维细胞（HPAAFs）组成的肺动脉外膜的 3D 生物打印模型。这种独特的生物材料通过两步聚合反应来模拟 PAH 发病机制。首先，PEG-αMA 大分子单体通过 3D 打印将酸性生物墨水溶液交联到碱性明胶支撑浴中，引发与合成和可生物降解的交联剂的碱催化硫醇-烯反应。然后，通过未反应的αMA 端基的光引发均聚合诱导基质变硬。通过实验设计方法生产的水凝胶平台具有初始弹性模量（），其范围在健康肺动脉组织范围内（= 4.7 ± 0.09 kPa），可变硬至高血压组织的病理范围（= 12.8 ± 0.47 kPa），并随时间支持细胞增殖。在变硬的水凝胶中培养的 HPAAFs 表达纤维标记物α-平滑肌肌动蛋白的比例高于在软水凝胶中的细胞（88 ± 2%比 65 ± 4%）。同样，在变硬的模型中，增殖标记物 5-乙炔基-2'-脱氧尿苷（EdU）呈阳性的 HPAAFs 的比例（66 ± 6%）高于软模型（39 ± 6%）。这些结果表明，3D 生物打印的可光调控肺动脉外膜模型是一种研究纤维化发病机制的工具。
