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International Journal of Bioprinting 3D bioprinting for vascular regeneration

further enhancing their regenerative potential. By combining 3D printing technology, drug-loaded nanoparticles, and
EPCs, this study demonstrated the potential of this approach in fabricating functional artificial blood vessels.

Keywords: 3D bioprinting; Tissue engineering; Nanoparticles; Artificial blood vessel; Restenosis; Endothelial progeni-
tor cells

1. Introduction most commonly used method. It typically involves the
continuous or layered deposition of bioink composed of
The human circulatory system heavily relies on an intricate living cells and support materials through a nozzle. This
network of blood vessels to ensure the transportation of technique enables the tissue-specific 3D bioprinting of
oxygen, nutrients, and crucial molecules to all organs intricate organ structures. It offers versatility, high speed,
and tissues. However, vascular pathologies, such as and excellent cell viability, making it advantageous for tissue
1,2
atherosclerosis, vascular occlusions, and congenital engineering applications. 20-22 Jetting-based bioprinting, on
malformations, present significant challenges to the the other hand, employs precise nozzle-based ejection of
integrity and functionality of these essential conduits. small droplets of bioink-containing cells and biomaterials.
Consequently, the development of innovative strategies to This method boasts high precision and resolution, allowing
replace or regenerate damaged blood vessels has become a for the creation of detailed tissue structures. It excels in
pivotal area of investigation within the field of regenerative its ability to deposit droplets with precision, making it
medicine. 3-6 suitable for mimicking complex vascular networks and
Recent advances in stem cell research have shown other intricate tissues. 23-25 Vat photopolymerization-based
great promise in tissue engineering and regenerative bioprinting relies on selectively curing liquid photopolymer
therapies. 5,7,8 Vascular endothelial stem cells, in particular, materials layer by layer using ultraviolet light. This
have emerged as a compelling candidate due to their technique is capable of achieving high-resolution, intricate
unique ability to differentiate into mature endothelial tissue structures and offers flexibility in using various
cells—the fundamental building blocks of blood vessels. 9-11 biocompatible photopolymer materials. 26-28 These 3D
Leveraging the regenerative potential of these cells presents bioprinting techniques hold promise in replicating highly
a remarkable opportunity to create artificial blood vessels detailed and complex organ structures, similar to those
that closely mimic their natural counterparts. found in the human body. They offer advantages such as
precision, high resolution, and material versatility, making
One critical aspect of tissue engineering is the
establishment of a functional vascular network within them valuable tools in the field of tissue engineering.
artificial constructs. 12,13 The presence of proper endothelial In this regard, nanoparticles (NPs) carrying
cells is crucial to maintaining vessel integrity, preventing therapeutic agents have emerged as a powerful tool. The
thrombosis, and facilitating appropriate blood flow. This NPs utilized in this study are composed of mesoporous
underscores the significance of vascular endothelial stem silica, characterized by their extremely small size and
cells, as their potential to differentiate into functional porous nature, with an average pore diameter of ~5 nm.
endothelial cells offers a viable solution to this challenge. 13-16 This porosity allows for efficient drug release in proportion
By incorporating these stem cells, it becomes feasible to to its size. 29,30 Furthermore, it is feasible to produce these
engineer blood vessels with a well-established endothelial nanoparticles at such a small size in large quantities. When
lining, thereby enhancing the overall performance and employed within a drug delivery system, the NPs gradually
durability of artificial constructs. Furthermore, to ensure release their contents when introduced into the biological
the long-term success of artificial blood vessels, it is essential system, highlighting their potential in imposing long-
to address issues such as restenosis and thrombosis. 17-19 term effects. However, a comprehensive understanding of
the biocompatibility of NPs has yet to be established. To
Tissue-engineered artificial blood vessels can closely
mimic human vascular structures. Recent research efforts address this concern, the study investigated the effects of
the NPs through in vitro and in vivo experiments.
have been extensive in replicating complex vascular
networks, akin to human blood vessels, using various three- Every drug possesses distinctive molecular structures
dimensional (3D) bioprinting techniques. Among these, and characteristics. However, when encapsulated within
extrusion-based bioprinting, jetting-based bioprinting, NPs, these drugs can be transformed into materials
and vat photopolymerization-based bioprinting are with precisely engineered properties. In this study, we
prominent methods. Extrusion-based bioprinting is the engineered NPs with the specific aim of tailoring their

Volume 10 Issue 2 (2024) 350 doi: 10.36922/ijb.1465