Abstract P2-15-06: Light-based bioprinting of vascularized fatty tissue for the development of biological breast implants
Authors: Hedemann Nina , Thomas Alexander , Tribian Nils , Kloke Lutz , Bauerschlag Dirk , van Mackelenbergh Marion 
Published: March 2023

Abstract
Although multi-modal and ablative treatment strategies for breast cancer are becoming more popular, partial or full mastectomy is still a most common intervention. While proving to be effective in curing the cancer, it leaves the patient disfigured, which can pose a considerable psychological burden. Hence, reconstructive breast surgery is continuing to increase in importance as it offers the possibility to at least partially restore the original look of the breast. Autologous adipose tissue transfer techniques, amongst them the surgical gold standard flap surgery and liposuction-based fat grafting, present natural solutions with the patient’s own tissue, but either produce a considerable secondary wound or are insufficient to address larger defects. Synthetic solutions like silicone implants on the other hand can also be used to fill large defects and only require minimal surgical intervention, but suffer from foreign body-associated complications like fibrosis. Tissue engineering biological breast implants of arbitrary size with no or minor insult to the patient’s body and excellent biocompatibility, exclusively using biomaterials and patient-specific adipose cells, could open a new chapter for breast reconstruction. Such an approach has become an intriguing possibility through the rise of powerful biofabrication technologies in the last two decades, namely three-dimensional bioprinting. Bioprinting marries additive manufacturing with biomaterials and living cells with the aim to create life-mimicking tissues and organs, and while it is mainly focused on research today, current endeavors push for application in regenerative medicine. In our work we sought to fabricate adipose tissue constructs using light-based bioprinting to investigate the potential application of such technology for future reconstructive breast surgery. The engineered tissue blocks were designed to mimic native human adipose tissue by comprising fat, connective tissue and endothelial cells. Being specifically placed by the bioprinter within extracellular matrix-like hydrogels, the cells were cultured in vitro and differentiated within the cultivation time of up to 4 weeks to form an adipose-like tissue. Live imaging showed high viability of bioprinted tissue blocks over the whole cultivation period and pronounced cellular reorganization. Confocal and histological analyses revealed a dynamic tissue maturation process with increasing proportions of differentiated adipocytes, ECM remodeling and formation of microvascular structures. In conclusion, the obtained results gave proof to the concept of engineering adipose tissue through bioprinting and could lay the groundwork for the development of all-natural biological breast implants.
Citation Format: Nina Hedemann, Alexander Thomas, Nils Tribian, Lutz Kloke, Dirk Bauerschlag, Marion van Mackelenbergh. Light-based bioprinting of vascularized fatty tissue for the development of biological breast implants [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-15-06.