A review of strategies for improving the mechanical properties of 3D bioprinted skin grafts

As the largest organ of the human body, the skin serves as a crucial protective barrier against external damage. While traditional approaches to skin injury treatment increasingly struggle to meet clinical demands, three-dimensional (3D) bioprinting has emerged as an innovative approach for tissue-engineered skin regeneration. Nevertheless, challenges persist regarding the mechanical integrity of bioprinted constructs, particularly post-printing graft shrinkage. This review systematically examines three key strategies for enhancing the mechanical properties of 3D bioprinted skin grafts: (i) Biomaterial innovation through novel material development and composite systems that substantially improve structural stability; (ii) Advanced structural design incorporating bioinspired architectures, topological optimization, and gradient configurations to achieve biomimetic mechanical performance; (iii) Post-fabrication processing techniques involving novel crosslinking methods and parameter modulation to reinforce mechanical strength. By critically analyzing these synergistic enhancement strategies, this work establishes a conceptual framework to guide future research in developing clinically viable 3D bioprinted skin substitutes with optimal biomechanical functionality.