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Underrepresentation of female students and specific racial/ethnic groups persists in STEM despite decades of intervention. Evidence suggests a need to encourage interest in STEM fields at the middle-school level. Adolescent career aspirations are influenced by exposure to role models and mindsets, such as a sense of perceived personal capacity. The purpose of this study was to measure how exposure to role models and work-based microbadging affects students’ mindsets related to pursuit of STEM careers. Middle school students rated their intent to pursue a STEM career before and after completing a series of Quest-Challenge pairs featuring role models, including a biomedical engineer, in the Couragion application, along with their confidence, motivation, and enjoyment through in-app surveys. Data from students in well-represented and underrepresented STEM demographics were compared. Intent to pursue a STEM career increased after Couragion app intervention. Divided into demographic groups, increases were observed in students from underrepresented racial/ethnic groups and female students. Students reported increased confidence, motivation, and enjoyment after interacting with the app. Additionally, students reported confidence in STEM career success and motivation to apply themselves academically. This study showed increased intent, confidence, motivation, and enjoyment in middle school students related to STEM careers. The Couragion app intervention effectively improved metrics that inform students’ future academic and professional decisions. Widely implementing this type of intervention during middle school could help narrow the representation gap in STEM fields. 

Idiopathic pulmonary fibrosis (IPF) is a devastating lung disease that progressively and irreversibly alters the lung parenchyma, eventually leading to respiratory failure. The study of this disease has been historically challenging due to the myriad of complex processes that contribute to fibrogenesis and the inherent difficulty in accurately recreating the human pulmonary environment in vitro . Here, we describe a poly(ethylene glycol) PEG hydrogel-based three-dimensional model for the co-culture of primary murine pulmonary fibroblasts and alveolar epithelial cells that reproduces the micro-architecture, cell placement, and mechanical properties of healthy and fibrotic lung tissue. Co-cultured cells retained normal levels of viability up to at least three weeks and displayed differentiation patterns observed in vivo during IPF progression. Interrogation of protein and gene expression within this model showed that myofibroblast activation required both extracellular mechanical cues and the presence of alveolar epithelial cells. Differences in gene expression indicated that cellular co-culture induced TGF-β signaling and proliferative gene expression, while microenvironmental stiffness upregulated the expression of genes related to cell–ECM interactions. This biomaterial-based cell culture system serves as a significant step forward in the accurate recapitulation of human lung tissue in vitro and highlights the need to incorporate multiple factors that work together synergistically in vivo into models of lung biology of health and disease. 

Fibrotic disorders account for over one third of mortalities worldwide. Despite great efforts to study the cellular and molecular processes underlying fibrosis, there are currently few effective therapies. Dual-stage polymerization reactions are an innovative tool for recreating heterogeneous increases in extracellular matrix (ECM) modulus, a hallmark of fibrotic diseases in vivo . Here, we present a clickable decellularized ECM (dECM) crosslinker incorporated into a dynamically responsive poly(ethylene glycol)-α-methacrylate (PEGαMA) hybrid-hydrogel to recreate ECM remodeling in vitro . An off-stoichiometry thiol–ene Michael addition between PEGαMA (8-arm, 10 kg mol −1 ) and the clickable dECM resulted in hydrogels with an elastic modulus of E = 3.6 ± 0.24 kPa, approximating healthy lung tissue (1–5 kPa). Next, residual αMA groups were reacted via a photo-initiated homopolymerization to increase modulus values to fibrotic levels ( E = 13.4 ± 0.82 kPa) in situ . Hydrogels with increased elastic moduli, mimicking fibrotic ECM, induced a significant increase in the expression of myofibroblast transgenes. The proportion of primary fibroblasts from dual-reporter mouse lungs expressing collagen 1a1 and alpha-smooth muscle actin increased by approximately 60% when cultured on stiff and dynamically stiffened hybrid-hydrogels compared to soft. Likewise, fibroblasts expressed significantly increased levels of the collagen 1a1 transgene on stiff regions of spatially patterned hybrid-hydrogels compared to the soft areas. Collectively, these results indicate that hybrid-hydrogels are a new tool that can be implemented to spatiotemporally induce a phenotypic transition in primary murine fibroblasts in vitro .