A composite bioink derived from lacrimal gland extracellular matrix and alginate

With the high global prevalence of dry eye disease and around 17% attributed to aqueous deficient dry eye (ADDE), there is an urgent need for therapies targeting lacrimal gland (LG) insufficiency. Advancements in in vitro LG analysis are essential for developing effective treatments that allow for efficient, ethical, and comprehensive evaluation of both cell-based therapies and pharmaceuticals. In light of the rapid progress in 3D bioprinting for tissue engineering, this study focuses on creating a composite hydrogel derived from decellularized porcine LG, combined with alginate. This combination leverages the bioactivity of the decellularized extracellular matrix (dECM) with the favorable biomechanical properties of alginate in a single bioink. Our results demonstrate that dECM supports the in vitro culture of LG cell types effectively, while alginate provides enhanced biomechanical stability. We analyzed the biomechanical and rheological properties of the bioink and printed 3D structures containing LG-derived cells, assessing cell viability both immediately post-printing and over a 7-day culture period. The LG-based bioink showed shear-thinning behavior, reduced cell sedimentation, and resilience to shear stresses comparable to pure alginate hydrogels. Additionally, we observed excellent viability of LG epithelial and mesenchymal stromal cells. This composite bioink, combining dECM and alginate, presents improved biomechanical properties while preserving biofunctionality, representing a promising platform for in vitro LG tissue engineering.