# Paper-based cultures supporting tissue-like structures for biochemical studies of oxygen gradients and screening applications > **NIH NIH R35** · UNIV OF NORTH CAROLINA CHAPEL HILL · 2024 · $368,474 ## Abstract MIRA Abstract This MIRA renewal builds upon the success of our efforts to develop a readily accessible culture platform to generate tissue-like structures and quantify cellular responses in physiologically relevant environments. Oxygen is a master regulator of cellular function, responsible for systematic reprogramming under hypoxic conditions and fine-tuning as oxygen supplies decrease. The tissue environment is spatially and temporally dynamic, responding to changes in oxygen and nutrient supplies as well as localized and systemic gradients of cell- generated signaling molecules. Despite the complexity of the tissue microenvironment, laboratories have relied on monolayer cultures due to standardized procedures for setup and analysis. We recognized the need for a culture platform to study cellular responses in defined tissue-like architectures whose extracellular microenvironment could be engineered and quantified. The paper-based culture platform represents a readily adoptable platform, which is modular in design and has a low technical barrier to entry. By stacking cell-laden sheets of paper, tissues are generated on demand. Our continued efforts include technological advances and the systematic study of oxygen's role in regulating (1) Estrogen signaling pathways in mammary tissue models. (2) The post-differentiation of drug-metabolizing enzymes of hepatocytes in a sinusoid model. We showed that hypoxia alters the regulation of estrogen receptor alpha (ERa) in ER+ breast lines, decreasing transactivation but maintaining similar amounts of protein in the presence and absence of estrogen. These results are markedly different from monolayers of the same cells in hypoxia. As we continue to develop the mammary tissue model, we will include stromal components to determine how they (alone and in concert with hypoxia) alter estrogen signaling. Our goal is to use a multi-pronged approach to generate a map of the "estrome," visualizing the transcriptional, translational, and activity changes of ERa and ERb to better predict in vivo outcomes. Our characterization of HepaRG cells under representative periportal and perivenous oxygen tensions shows its importance in the post-differentiation expression and activity of drug-metabolizing enzymes and transport proteins. We will continue to develop a sinusoid model that can characterize the HepaRG cells under a full range of oxygen tensions that span the sinusoid in vivo, incorporating non-parenchymal cells known to provide morphogens that promote this process and including flowing medium to simulate the constant exchange occurring in the sinusoid. The previous funding period's biological inquiries and technological developments enable these new directions. We will continue to incorporate commonly used analysis tools while developing ways to characterize the system further while not straying from the original goal of a modular platform that is both reproducible and quickly adopted. Our biological inquiries will... ## Key facts - **NIH application ID:** 10765243 - **Project number:** 2R35GM128697-06 - **Recipient organization:** UNIV OF NORTH CAROLINA CHAPEL HILL - **Principal Investigator:** Matthew Ryen Lockett - **Activity code:** R35 (R01, R21, SBIR, etc.) - **Funding institute:** NIH - **Fiscal year:** 2024 - **Award amount:** $368,474 - **Award type:** 2 - **Project period:** 2018-07-05 → 2029-06-30 ## Primary source NIH RePORTER: https://reporter.nih.gov/project-details/10765243 ## Citation > US National Institutes of Health, RePORTER application 10765243, Paper-based cultures supporting tissue-like structures for biochemical studies of oxygen gradients and screening applications (2R35GM128697-06). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10765243. Licensed CC0. --- *[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*