IADR Abstract Archives
Salivary Spheroids Respond to FGFR2b Stimulation in ECM-Modified 3D Hydrogels
Objectives: Loss of salivary gland secretory acini resulting from radiation therapy in patients with head and neck cancer leads to xerostomia, which abrogates oral homeostasis and decreases the quality of life. Generation of a functional, implantable, tissue-engineered salivary gland will provide relief to these patients. Previous work has shown self-assembly of human salivary acinar-derived cells (hSACs) into functional spheroids when encapsulated in 3D hyaluronic acid (HA)-based hydrogels. To maximize surface area for efficient production and transport of saliva, a branched glandular architecture is essential. The goal of this study was to differentiate clusters of hSACs into interconnected “branched” structures by providing an ECM-rich scaffold and stimulating with FGF7/10 to promote glandular morphogenesis.
Methods: An IRB-approved protocol was used to obtain human parotid gland tissue from patients undergoing head and neck surgery. hSACs were isolated and cultured as previously described. Cells were encapsulated in 3D HA/laminin-based hydrogels. Resulting spheroids were treated with FGF7/10.
Results: hSACs seeded in 3D HA/laminin hydrogels assembled into clusters (20-40μm diameter), within 7 days. Clusters treated with FGF10 or FGF7 showed increased proliferation and phosphorylation of Erk1/2 and Akt, indicating activation of FGFR2b. FGF7 treatment increased branching within complex structures, while FGF10 treatment produced elongated morphologies FGF10 followed by FGF7 treatment generated lobular structures with extensions. Addition of heparan sulfate enhanced bioactivity of FGF10 and produced complex multi-lobular structures reminiscent of the native gland. Prolonged culture with FGF7/10 promoted lumen formation within many lobular regions.
Conclusions: hSAC clusters undergo distinct morphological changes in response to FGF7/10 in 3D ECM-modified hydrogels. These changes occur through activation of FGFR2b, which is ubiquitously expressed in these clusters. Integration of morphogenic growth factors in the correct spatiotemporal fashion can generate organized glandular units that can potentially be functional in animal models and then in patients suffering from xerostomia.
Methods: An IRB-approved protocol was used to obtain human parotid gland tissue from patients undergoing head and neck surgery. hSACs were isolated and cultured as previously described. Cells were encapsulated in 3D HA/laminin-based hydrogels. Resulting spheroids were treated with FGF7/10.
Results: hSACs seeded in 3D HA/laminin hydrogels assembled into clusters (20-40μm diameter), within 7 days. Clusters treated with FGF10 or FGF7 showed increased proliferation and phosphorylation of Erk1/2 and Akt, indicating activation of FGFR2b. FGF7 treatment increased branching within complex structures, while FGF10 treatment produced elongated morphologies FGF10 followed by FGF7 treatment generated lobular structures with extensions. Addition of heparan sulfate enhanced bioactivity of FGF10 and produced complex multi-lobular structures reminiscent of the native gland. Prolonged culture with FGF7/10 promoted lumen formation within many lobular regions.
Conclusions: hSAC clusters undergo distinct morphological changes in response to FGF7/10 in 3D ECM-modified hydrogels. These changes occur through activation of FGFR2b, which is ubiquitously expressed in these clusters. Integration of morphogenic growth factors in the correct spatiotemporal fashion can generate organized glandular units that can potentially be functional in animal models and then in patients suffering from xerostomia.