3D Bioprinting
3D bioprinting is a relatively new technology that holds immense promise to revolutionize medical treatments by enabling the creation of personalized implants, organs, and tissues, addressing the shortage of donor organs, eliminating the reliance on animal testing, and reducing the risk of transplant rejection. However, challenges remain, including developing biocompatible materials and optimizing the printing process to ensure cell viability. Our goal is to overcome the aforementioned challenges and explore the full potential of 3D bioprinting to fabricate customized, functional biological structures with precision, opening new horizons in healthcare and medical research. It involves the precise layer-by-layer deposition of biological materials, such as living cells and biomaterials, to create functional three-dimensional structures that mimic the complexity of native human tissues and organs.
Design and Manufacturing of Conducting and Biocompatible Hydrogel
Conducting hydrogels has gained substantial attention in bioelectronics and tissue engineering due to their exceptional electrical conductivity and compatibility with soft biological tissues. Nevertheless, the conventional methods for hydrogel fabrication, such as casting and transfer printing, are challenging to achieve high-resolution complex geometry. This constraint carries profound implications for biomedical applications where precision in biosensing and monitoring is crucial, while the natural extracellular matrix (ECM) requires nano/micro-scale precision. Furthermore, the use of surface coatings on devices can jeopardize their durability, posing challenges for sustained usage.
To address these challenges, this study developed an innovative approach for fabricating nano/microscale structures from conductive hydrogels through the Two-Photon Polymerization (TPP) process, which remained unexplored to date. In this approach, various hydrogel solutions were formulated, incorporating suitable additives, and their compatibility with TPP-based printing was assessed via rheological analysis and printing window characterization. The novel hydrogel material showcased enhanced swelling, electrical properties, and biocompatibility compared to their unmodified conductive counterparts.
To demonstrate the efficacy of the TPP process in printing the novel hydrogel material, conventional micro-scale 2D and 3D structures were fabricated. Notably, conducting microwires and micro-capacitors were printed and subsequently evaluated for their electronic, energy storage, and sensing capabilities. Furthermore, a 3D scaffold tailored for tissue regeneration was successfully printed with exceptional structural accuracy. The biocompatibility of the hydrogel was validated by culturing human induced pluripotent stem cells (hiPSCs), demonstrating that the printed scaffold fosters cell growth and proliferation. These demonstrations highlight the potential of novel materials for biomedical and tissue engineering applications.
The direct printing of exceedingly conductive hydrogels via the TPP process exceeds the constraints of traditional conductive hydrogel manufacturing techniques. This breakthrough paves the way for novel applications in micro-energy storage devices, flexible micro/nanoelectromechanical systems (MEMS), and biomedical micro-devices. Combining high-resolution direct printing with the unique properties of hydrogel material presents promising prospects for driving progress in multidisciplinary fields.
