Assessing Bioactivity and Biointegration of Engineered Salivary Tissue Constructs in a Preclinical Unilateral Fractionated Irradiated Rat Model

Pernick, K.; Amorim, J.; da Silva Barros, C. C.; Vesela, I.; Lian, M.-J.; Nahass, S.; Geremias, T. C.; Swegal, W.; Farach, A. M.; Harrington, D.; Wu, D.; Farach-Carson, M. C.; Lombaert, I. M. A.

doi:10.64898/2026.05.11.724009

bioRxiv · 10.64898/2026.05.11.724009

Assessing Bioactivity and Biointegration of Engineered Salivary Tissue Constructs in a Preclinical Unilateral Fractionated Irradiated Rat Model

Pernick, K.·Amorim, J.·da Silva Barros, C. C.·Vesela, I.·Lian, M.-J.·Nahass, S.·Geremias, T. C.·Swegal, W.·Farach, A. M.·Harrington, D.·Wu, D.·Farach-Carson, M. C.·Lombaert, I. M. A.

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Abstract

Human salivary stem/progenitor cell (hS/PC)-loaded hyaluronic acid (HA)-based hydrogels, termed 3D-salivary tissue constructs (3D-ST), hold great promise for restoring salivary gland function post-radiation injury. Here, we developed a next-generation 3D-ST using heparin-modified HA and bioactive peptide-modified hydrogels. This new formulation enables controlled pre-loading and localized presentation of heparin-binding growth factors prior to surgical implantation, providing opportunities to enhance in vivo hS/PC bioactivity. To model clinically relevant radiation injury, we established an athymic rat model subjected to computed tomography (CT)-guided fractionated radiation, resulting in hallmark features of radiation-induced salivary dysfunction. Over 60-days post-irradiation, glands exhibited progressive loss of acini, increased fibrosis, and disruption of endothelial, neuronal, and myoepithelial compartments. Within this injured environment, a surgical pocket was created to precisely implant 3D-STs to assess graft performance. Fluorescent labeling of the 3D-STs enabled longitudinal tracking post-implantation. Over 14 days, implanted 3D-STs remained structurally stable within irradiated glands, and hS/PCs remained viable without evidence of local inflammatory responses. Compared to non-injured glands, the irradiated microenvironment suppressed hS/PC proliferation and phenotype, indicating alterations in the irradiated local tissue negatively impact hS/PC bioactivity. In addition, host neurovascular migration into the 3D-ST was majorly restricted in irradiated glands, providing new opportunities to enhance biointegration. Overall, this work establishes a reproducible preclinical framework for assessing hydrogel biocompatibility and stability, cell bioactivity, and host-graft biointegration prior to scale up into preclinical large animal models. This study has successfully established a tractable approach for improving 3D-ST formulations to enhance hS/PC expansion, differentiation, and biointegration following implantation into radiation-injured beds.

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Pernick, K., Amorim, J., da Silva Barros, C. C., Vesela, I., Lian, M.-J., Nahass, S., Geremias, T. C., Swegal, W., Farach, A. M., Harrington, D., Wu, D., Farach-Carson, M. C., Lombaert, I. M. A.. 2026-05-14. Assessing Bioactivity and Biointegration of Engineered Salivary Tissue Constructs in a Preclinical Unilateral Fractionated Irradiated Rat Model. https://doi.org/10.64898/2026.05.11.724009

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