PERSPECTIVE: Cryopreservation of cell-populated bioengineered constructs - a roadmap for challenges, strategies, and translation

The advancement of cell-populated bioengineered constructs (BECs) has created an ever-increasing demand for effective cryopreservation strategies that guarantee long-term storage without compromising structural integrity or biological function. By allowing constructs to be stored until required, cryopreservation helps align tissue construct unrestricted availability with patient needs and enables regenerative treatments to be initiated on demand. Through the prism of biomaterial properties, this review delves into the historical development and recent progress in the in toto (whole cell-biomaterial construct) cryopreservation of engineered artificial tissues. Particular emphasis is placed on elastic fibrous matrices, alginate-based solid and core-shell constructs, and bulk 3D micro and macroporous scaffolds, complemented by practical examples from the authors’ own research. Beyond these aspects, the review explores methods for recording freezing patterns within cell-free BECs to better characterize thermal events and establish reproducible frameworks with minimal construct-to-construct variability. Finally, this work surveys key regulatory considerations and translational barriers that must be overcome to achieve Good Manufacturing Practice (GMP)-compliant, clinically viable cryopreservation protocols for cell-populated BECs.