Hydrogels for 3D-printed breast scaffolds on esthetic, functional, and oncological safety: A review

Breast volume loss after cancer surgery severely affects patients' physical and psychological well-being, while traditional reconstruction methods such as prosthetic implantation and autologous tissue transfer are limited by complications, donor-site morbidity, and poor long-term stability. To address these issues, this review summarizes recent advances in hydrogel-based 3D-printed scaffolds for breast reconstruction. The review focuses on the use of different 3D bioprinting techniques in scaffold manufacture and compares natural and synthetic hydrogels in terms of biocompatibility, mechanical properties, and biodegradability. It also involves core design principles for scaffolds to meet the unique anatomical and functional requirements of the breast, including tunable softness, promotion of vascularization, and tissue integration. Furthermore, recent applications of hydrogel-based 3D printing in adipose tissue regeneration and nipple-areola complex reconstruction are discussed in detail. The findings indicate that natural hydrogels provide advantages in cell viability and differentiation due to their biocompatibility, while synthetic hydrogels offer tunability and structural stability for long-term support. Combining the two materials can enhance reconstruction outcomes. It further addresses challenges and prospective directions in 3D printing hydrogels in breast reconstruction, paving the way for innovative research to material selection and printing strategies, enhancing patient care, and improving quality of life.