Bioinspired Collagen/κ-Carrageenan 3D Matrix for <i>In Vitro</i> Modeling of Vascular Calcification

Pathological calcification of soft tissue, particularly in vascular structures, is a hallmark of several cardiovascular diseases and significantly contributes to vascular stiffening and dysfunction. Despite sharing similarities with physiological ossification, the mechanisms driving the transdifferentiation of mouse vascular smooth muscle cells (MOVAS) into osteochondroblast-like phenotypes remain poorly understood. This transdifferentiation plays a critical role in the initiation and progression of pathological calcification. In this study, we developed a bioinspired 3D scaffold, composed of type I collagen (Col) and κ-carrageenan (κ-Carr), designed to mimic key aspects of the vascular extracellular matrix (ECM). This novel scaffold provides a physiologically relevant platform to study soft tissue calcification under osteogenic conditions. We demonstrated that this 3D system supports MOVAS cell adhesion, spreading, and transdifferentiation into a mineralizing phenotype in a controlled manner, as evidenced by the overexpression of osteogenic markers (TNAP and RUNX2), increased alkaline phosphatase activity, and controlled calcium phosphate deposition. Spectroscopic and thermogravimetric analyses revealed the formation of carbonated apatite minerals and a calcium-deficient apatite structure, indicative of controlled mineral deposition within the organic matrix. The incorporation of κ-carrageenan enhanced the calcification process, underscoring the importance of biochemical cues in directing the MOVAS phenotype changes. This scaffold system effectively replicates the spatial organization and physicochemical cues of the vascular ECM, providing a unique and innovative model to study pathological calcification processes. Moreover, this approach holds significant potential for developing regenerative biomaterials and therapeutic strategies aimed at preventing vascular calcification, opening new avenues for clinical applications and therapeutic interventions in cardiovascular disease.