IADR Abstract Archives
Engineered Salivary Gland Tissue Chips
Objectives: Salivary gland dysfunction is a consequence of off-target radiation due to head and neck cancer treatments, Sjogren’s syndrome, and associated with a variety of commonly-prescribed drugs. Progress in gland dysfunction mechanistic understanding and development of new therapeutic strategies for salivary gland are hampered by the lack of in vitro models, as salivary gland cells (SGCs) rapidly (in <1 day) lose critical secretory function in vitro. The goal of this work is to engineer functional human salivary gland tissue chips for high-throughput drug screening.
Methods: To develop functional salivary gland tissues, we are synergizing two technologies: hydrogels and microbubble array (MBs). Hydrogel-encapsulated SGCs exhibit long-term survival and form polarized structures expressing Mist1, a secretory marker. Although these data are promising, Mist1 expression is reduced compared to native glands. Macroscale hydrogels preclude high-throughput use which is enabled using modular MB array technology platform. MBs are micron-scale spherical cavities molded in polydimethylsiloxane. MBs have the advantage of length scales and curvatures similar to gland acinar units to promote cell-cell contact and concentration autocrine-paracrine factors to enhance tissue function.
Results: Modifications to standard SGC isolation approaches significantly improves secretory function of tissues. Isolation of acinar-intercalated-ductal (AIDUC) tissues using mild tissue processing maintains ~10x Mist1 gene expression versus standard isolation protocols. Culture within MB and gel-MB significantly improves acinar gene expression. Mist1 is increased 2-4x and 20-40x in MB and gel-MB, respectively, and NKCC1 1.2-1.5x and 5-10x compared to AIDUCs cultured in tissue culture plates over 14 days. We have also shown that calcium signaling is maintained for >14 days in both murine and human SGCs cultured in gel-MB. Human SGCs adopt morphologies similar to murine SGCs when cultured in macrogels. Immunofluorescence staining suggests self-assembly recapitulates native gland structure.
Conclusions: Altogether, salivary gland tissue chips are being developed for drug screening to promote and/or protect salivary gland function.
Methods: To develop functional salivary gland tissues, we are synergizing two technologies: hydrogels and microbubble array (MBs). Hydrogel-encapsulated SGCs exhibit long-term survival and form polarized structures expressing Mist1, a secretory marker. Although these data are promising, Mist1 expression is reduced compared to native glands. Macroscale hydrogels preclude high-throughput use which is enabled using modular MB array technology platform. MBs are micron-scale spherical cavities molded in polydimethylsiloxane. MBs have the advantage of length scales and curvatures similar to gland acinar units to promote cell-cell contact and concentration autocrine-paracrine factors to enhance tissue function.
Results: Modifications to standard SGC isolation approaches significantly improves secretory function of tissues. Isolation of acinar-intercalated-ductal (AIDUC) tissues using mild tissue processing maintains ~10x Mist1 gene expression versus standard isolation protocols. Culture within MB and gel-MB significantly improves acinar gene expression. Mist1 is increased 2-4x and 20-40x in MB and gel-MB, respectively, and NKCC1 1.2-1.5x and 5-10x compared to AIDUCs cultured in tissue culture plates over 14 days. We have also shown that calcium signaling is maintained for >14 days in both murine and human SGCs cultured in gel-MB. Human SGCs adopt morphologies similar to murine SGCs when cultured in macrogels. Immunofluorescence staining suggests self-assembly recapitulates native gland structure.
Conclusions: Altogether, salivary gland tissue chips are being developed for drug screening to promote and/or protect salivary gland function.