Osteoarthritis (OA) is a common joint disorder with a significant economic and healthcare impact. The knee joint is composed of cartilage and the adjoining bone, a synovial capsule, the infrapatellar fat pad (IPFP), and other connective tissues such as tendons and ligaments. Adipose tissue has recently been highlighted as a major contributor to OA through strong inflammation mediating effects. In this study, methacrylated gelatin (GelMA) constructs seeded with adipose tissue-derived mesenchymal stem cells (ASCs) and cultured in a 3D printed bioreactor were investigated for use in microphysiological systems to model adipose tissue in the knee joint. Four patient-derived ASC populations were seeded at a density of 20 million cells/mL in GelMA. Live/Dead and boron-dipyrromethene/4′,6-diamidino-2-phenylindole (BODIPY/DAPI) staining of cells within the constructs demonstrated robust cell viability after 28 days in a growth (control) medium, and robust cell viability and lipid accumulation in adipogenic differentiation medium. qPCR gene expression analysis and protein analysis demonstrated an upregulated expression of key adipogenesis-associated genes. Overall, these data indicate that ASCs retain their adipogenic potential when seeded within GelMA hydrogels and cultured within perfusion bioreactors, and thus can be used in a 3D organ-on-a-chip system to study the role of the IPFP in the pathobiology of the knee OA.

There is a growing need for workers with STEM-aligned training in the modern global economy, but a paucity of workers to fill these positions. One important contributor to this issue is low student persistence in STEM. Nontraditional science courses that utilize more active-participation and learning are attractive as tools to increase student persistence and engender more interest in STEM. Herein is described the content and implementation of the undergraduate chemistry-based service-learning course, Chemistry 1898: Service Learning, that was offered in Spring 2019 at Tulane University. The goal of the course was to increase self-efficacy in chemistry and sustain undergraduate interest in STEM. The course also serves to increase STEM interest in the New Orleans public-school students. Chemistry 1898 features a well-rounded curriculum and diverse activities. The enrolled undergraduate students were not only taught chemistry concepts (general chemistry and supramolecular chemistry) but also asked to present the chemical concepts using attentiongrabbing demonstrations to public-school students in the New Orleans area. In addition, the course covered multiple nonscience topics, including the pedagogy of service-learning, background on the New Orleans publicschool system, and a guide for how to work with the community. The course also involved student reflection activities/surveys and interfaced with the Tulane Center for Public Service. Preliminary qualitative results from a set of anonymous pre-and poststudent surveys indicated that the undergraduate students gained self-efficacy in the general chemistry concepts covered in the course. Although the course did not have an effect on the career choices of the undergraduate students, the majority of the students were already very interested in a STEM career. Further, some students mentioned gaining a benefit in public speaking skills, and some considered the possibility of teaching and working with children in the future.

Osteoarthritis (OA) is a degenerative joint disease resulting in limited mobility and severe disability. Type II diabetes mellitus (T2D) is a weight-independent risk factor for OA, but a link between the two diseases has not been elucidated. Adipose stem cells (ASCs) isolated from the infrapatellar fat pad (IPFP) may be a viable regenerative cell for OA treatment. This study analyzed the expression profiles of inflammatory and adipokine-related genes in IPFP-ASCs of non-diabetic (Non-T2D), pre-diabetic (Pre-T2D), and T2D donors. Pre-T2D ASCs exhibited a substantial decrease in levels of mesenchymal markers CD90 and CD105 with no change in adipogenic differentiation compared to Non-T2D and T2D IPFP-ASCs. In addition, Cyclooxygenase-2 (COX-2), Forkhead box G1 (FOXG1) expression and prostaglandin E2 (PGE2) secretion were significantly increased in Pre-T2D IPFP-ASCs upon stimulation by interleukin-1 beta (IL-1β). Interestingly, M1 macrophages exhibited a significant reduction in expression of pro-inflammatory markers TNFα and IL-6 when co-cultured with Pre-T2D IPFP-ASCs. These data suggest that the heightened systemic inflammation associated with untreated T2D may prime the IPFP-ASCs to exhibit enhanced anti-inflammatory characteristics via suppressing the IL-6/COX-2 signaling pathway. In addition, the elevated production of PGE2 by the Pre-T2D IPFP-ASCs may also suggest the contribution of pre-diabetic conditions to the onset and progression of OA.