Speaker
Description
3D bioprinting has emerged as a promising technology in tissue engineering and regenerative medicine. Collagen, given its natural abundance in the extracellular matrix and excellent biocompatibility, serves as an ideal biomaterial for the preparation of printable bioinks. This study explores the optimization of collagen bioink properties as well as cultivation strategies and microvascular simulation to enhance the functionality of bioprinted constructs. We focused on improving cell viability, morphology, and metabolic activity within bioprinted collagen structures by optimizing the neutralization protocol of highly concentrated collagen hydrogels (up to 50 mg/mL), which included two successive neutralization steps using a 2× concentrated culture medium and NaOH for precise pH adjustment [1]. This process was supported by a semi-automated, custom-built mixing system featuring colorimetric pH estimation, ensuring high consistency and reproducibility in bioink preparation, and printed using a custom bioprinter utilizing syringe-based extrusion. Alongside, we investigated the impact of active media perfusion during cultivation. Compared to static culture, active perfusion significantly improved cell viability and metabolic activity within highly concentrated collagen constructs [2]. The dynamic perfusion environment enhanced nutrient and gas delivery and waste removal, which supported the development of more viable, structurally robust, and functional bioprinted tissues. To further support cell proliferation and tissue maturation in thick (>1.5 mm) samples, we developed a novel microchannel fabrication strategy, since achieving a high proliferation rate in thick constructs remains a challenge. By printing highly concentrated collagen bioink directly onto a horizontal array of thin needles, we generated continuous, organized microchannels throughout the constructs. These structures significantly expanded the diffusion surface area, which improved cell viability in thicker samples. Overall, the integration of optimized bioink preparation, active media perfusion, and precise microchannel engineering offers a strategy for enhancing the viability, structural integrity, and functionality of thick, bioprinted collagen-based constructs. These advancements hold significant promise for future cardiovascular applications, potentially revolutionizing treatments and therapies in this field.
This research was funded by the Ministry of Health of the Czech Republic grant No. NW24-08-00064 and NW24J-02-00061 and by the Grant Agency of the Czech Technical University in Prague (grant No. SGS25/183/OHK4/3T/17).
[1] Matejkova, J.; Kanokova, D.; Supova, M.; Matejka, R. A New Method for the Production of High-Concentration Collagen Bioinks with Semiautonomic Preparation. Gels 2024, 10, 66.
[2] Kanokova, D.; Matejka, R.; Zaloudkova, M.; Zigmond, J.; Supova, M.; Matejkova, J. Active Media Perfusion in Bioprinted Highly Concentrated Collagen Bioink Enhances the Viability of Cell Culture and Substrate Remodeling. Gels 2024, 10, 316.
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