3D Bioprinting of Brown Adipose Tissue

Recent advances in biotechnology have opened up intriguing possibilities in the field of 3D bioprinting, especially in the area of regenerative medicine. One particularly exciting prospect is the 3D bioprinting of brown adipose tissue (BAT). This specialized fatty tissue plays a crucial role in thermogenesis, or heat production, by converting stored energy from lipids. Primarily found in human infants, hibernating animals, and some adults who require additional heat sources, BAT diminishes significantly as humans age. This essay explores the potential of 3D bioprinting BAT for therapeutic applications, particularly in aiding fat loss and providing warmth in cold climates.

Significance of Brown Adipose Tissue

Brown adipose tissue is vital for thermoregulation in neonates due to their higher head-to-body ratio, limited capacity for shivering, and slower physiological responses to cold. In adults, BAT offers additional benefits, such as facilitating fat loss. The tissue is metabolically active, consuming lipids to generate heat, making it a promising target for scientists and companies interested in the lucrative fat loss market.

In children, BAT is essential for maintaining body temperature, a critical function given their inability to retain heat as effectively as adults. The presence of BAT in infants helps mitigate heat loss predominantly through their heads. However, as humans mature, BAT levels significantly decrease, diminishing its role in thermogenesis. Despite this reduction, research indicates that BAT in adults still contributes to energy expenditure, making it a potential ally in combating obesity.

3D Bioprinting: The Methodology

The goal of bioprinting BAT is to create a biological and safe method for fat reduction in adults. This involves designing a highly vascularized tissue structure, given BAT's need for a rich blood supply to facilitate nutrient exchange, waste removal, and heat distribution. The bioprint must incorporate capillaries, ensuring no BAT is more than 200 micrometers away from a capillary to maintain adequate vascularization.

To achieve this, two primary design strategies are considered: incorporating pores or creating blood vessels using a sacrificial bioink. Recent studies suggest that a more solid 3D print increases cell viability, contrary to expectations. Therefore, a thin, oval, or spherical bioprint is proposed, mimicking the anatomical structure of adult BAT while simplifying vascularization and implantation.

Choosing the Right 3D Printer

Among the various 3D bioprinting methods, extrusion printers are favored for their gentle handling of cells. These printers extrude materials using pneumatics, pistons, or screws, avoiding the cell damage associated with droplet or laser-based printers. The extrusion method allows for the use of larger tips, minimizing shear forces that could rupture cells.

Additionally, the printer must support multiple bioinks. This dual-tip capability enables the integration of cells and hydrogels to form BAT, alongside a sacrificial bioink like Pluronic for vascularization. Pluronic undergoes reverse gelation, facilitating vascular creation by liquefying and evacuating post-printing.

Materials and Cell Culture

The choice of hydrogels is crucial in maintaining cell viability. A combination of hyaluronic acid and gelatin provides an optimal environment, supporting cell adhesion, differentiation, migration, and proliferation. These hydrogels are compatible with extrusion printing and require post-print crosslinking, typically achieved through photo-crosslinking. This process enhances the structural integrity of the print and improves cell viability.

BAT consists of both brown and white adipose tissues, necessitating the inclusion of both cell types in the bioprint. Adipocytes, the progenitors of these cells, are cultured and differentiated before incorporation into the hydrogel matrix. Following printing, the bioprint is transplanted into areas with high fat content to promote localized fat loss.

Post-Printing Evaluation

Assessing the functionality of 3D-bioprinted BAT is crucial. Fat loss in targeted areas is a primary indicator of success, but a more precise method involves live-dead cell assays. This technique uses fluorescent dyes to differentiate between viable and non-viable cells, ensuring the print's effectiveness in vivo.

In conclusion, the 3D bioprinting of brown adipose tissue holds significant promise as a solution for fat loss and thermoregulation. By leveraging advanced printing techniques and materials, researchers aim to create a viable BAT implant that addresses the needs of individuals seeking weight loss or enhanced thermal regulation. This innovative approach not only advances our understanding of tissue engineering but also offers a potentially transformative tool in the fight against obesity.

Did you like this example?

351

18