biostudies-literatureUnknown15(1)Davis-Hall DRose Community FoundationNational Cancer Institute of the NIHNHLBI NIH HHSNCI NIH HHSLudeman Family Center for Women’s Health Research at the University of Colorado Anschutz Medical CampusU.S. ArmyColorado Pulmonary Vascular Disease Research AwardGraduate Research Fellowship ProgramNational Heart, Lung, and Blood Institute of the National Institutes of HealthNational Science FoundationPulmonary 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 of<i>in vitro</i>screening 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 pathogenesis<i>in vitro</i>through 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 (<i>E</i>) within the range of healthy pulmonary arterial tissue (<i>E</i>= 4.7 ± 0.09 kPa) that was stiffened to the pathologic range of hypertensive tissue (<i>E</i>= 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<i>in vitro</i>.Biofabricationhttps://www.ebi.ac.uk/biostudies/studies/S-EPMC9933849biostudies-literature3D-bioprinted, phototunable hydrogel models for studying adventitial fibroblast activation in pulmonary arterial hypertension.PMC9933849DGE 1841052T32 HL072738F31 HL1511221941401K25 HL148386R21 CA252172R01 HL153096W81XWH-20-1-0037R01 HL080396Magin CMThomas EPena BDavis-Hall Dfalse3D-bioprinted, phototunable hydrogel models for studying adventitial fibroblast activation in pulmonary arterial hypertension.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 of<i>in vitro</i>screening 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 pathogenesis<i>in vitro</i>through 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 (<i>E</i>) within the range of healthy pulmonary arterial tissue (<i>E</i>= 4.7 ± 0.09 kPa) that was stiffened to the pathologic range of hypertensive tissue (<i>E</i>= 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<i>in vitro</i>.2022-01-01T00:00:00Z2022 Dec2025-04-04T03:00:04.708Z2025-04-04T03:00:04.708ZS-EPMC99338493653372810.1088/1758-5090/aca8cf