Page 138 - IJB-9-2

International Journal of Bioprinting Hybrid biofabrication of neurosecretory structures

1. Introduction secretory function after transplantation in mice . Yu et
[22]
al. used parathyroid tissue and adipose-derived acellular
Neuroendocrine organs play an important role in extracellular matrix bioink to print a pre-designed
maintaining the survival of the human body, regulating the polycaprolactone (PCL) grid . The results of in vivo
[23]
balance of the environment, protecting human tissue from transplantation in rats showed that parathyroid tissue could
emergency responses, and avoiding external infection . maintain its activity for 4 weeks and exhibited the function of
[1]
Major brain trauma, vascular diseases, tumors, and other secreting parathyroid hormone. Zubizarreta et al. printed a
insults can lead to loss of function of neurosecretory model of the female reproductive system in vitro through 3D
organs, which leaves patients prone to infection, hormone bioprinting . Because many endogenous and exogenous
[24]
imbalance, systemic complications, and even death due factors affect female reproductive health and fertility, its
to low hormones . Even partial removal of endocrine function is to provide hormonal support and an anatomical
[2]
organs can cause loss of endocrine function, which structure for the production of new offspring. Diao et al.
often necessitates long-term additional hormone drug established a growth hormone pituitary adenoma model
replacement therapy in affected individuals. In addition, by 3D bioprinting, which showed that pituitary adenoma
the systemic side effects caused by drugs are new factors cells presented more active cell cycle progression and had
[3]
threatening the health of patients . characteristics of proliferation and invasion of pituitary
[25]
Since the regeneration of endocrine organs remains a huge adenoma cells . However, there remains a huge demand for
challenge, biological manufacturing processes have become 3D bioprinting of neurosecretory structures with secretory
a viable option in this regard. The manufactured endocrine function for development and translational purposes.
organs not only require new biological manufacturing A single manufacturing technology often has inherent
technologies for the implementation and maintenance of defects in the manufacture of complex organs with special
better organ characteristics, but also needs to be long-term needs. However, hybrid biofabrication, which involves various
and safe in nature as well as have a stable structure and complementary biological manufacturing technologies,
effective secretory function . Recently, as a new biological avoids the defects of a single manufacturing technology and
[4]
manufacturing technology, 3D bioprinting has been gradually gives full play to their respective advantages, better realizing
translated into clinical application, which has shown great the biological manufacturing and functional reconstruction
potential in overcoming existing clinical challenges . Three- of complex organs [26,27] . Xu et al. used electrospinning of
[5]
dimensional (3D) bioprinting is based on computer-aided polycaprolactone fiber and inkjet bioprinting of rabbit
living cell biomanufacturing technology, including extrusion elastic chondrocytes suspended in fibrin-collagen hydrogel
(mechanical and pneumatic) [6,7] , jetting (inkjet, microvalve, alternately to construct a 3D structure layer-by-layer to
laser-assisted, and acoustic) [8,9] , and vat polymerization achieve a cartilage-like tissue formation, cartilage repair, and
(stereolithography, digital light processing, and two-photon regeneration in vivo . This method not only addressed the
[28]
polymerization) [10,11] . Irrespective of the type of bioprinting demand for cartilage strength, but also solved the problem of
technology, the purpose is to deposit cells, biomaterials, and matrix microenvironment for the growth of chondrocytes.
cytokines with high precision and to accurately control the Hwang et al. developed a hybrid-encapsulated islet system
spatial geometry, density, and controllable distribution of based on biological printing technology, which not only
loaded cells to realize 3D construction of a 3D-bioprinted protected the growth microenvironment of islet cells from
structure [12,13] . 3D bioprinting tissues has been reported, attack by the immune system, but also provided a suitable
including 3D-bioprinted liver tissue [14-16] , glomerulus , matrix environment to maintain the viability, proliferation,
[17]
myocardial , brain , and skeletal muscle and has been and insulin production of islet cells . Yoon et al. used
[19]
[20]
[18]
[29]
shown to maintain cell bioactivity, tissue morphological 3D-bioprinted hydrogel and electrospun flexible nanofibers
structure, and organoid function. The tissue-like structures to create 3D structures alternately, which could better achieve
produced by the organisms also showed varying degrees of shape fidelity, maintain structural accuracy, improve the
biological functions. However, there is little research in the mechanical properties of compressive strength, modulus,
field of the biological manufacture of endocrine organs in and springback limit, and even help open internal channels
3D bioprinting. Wu et al. constructed a 3D ovarian follicular for perfusion culture, ultimately generating bioprinted
microenvironment using a 3D printing system based on 3D structures to maintain stronger biological activity .
[30]
gelatin methacryloyl (GelMA) and found that follicles grew Hybrid biofabrication combined with 3D bioprinting
and ovulated successfully in scaffolds and that metaphase II and electrospinning technology avoids the problem of
oocytes were present after maturation in vitro . Bulanova insufficient structural strength of a simple hydrogel system
[21]
et al. used bioprinting technology to construct functional and could maintain structural stability and better cell activity
vascularized mouse thyroid structures in vitro and showed for a longer time. Simultaneously, hybrid biofabrication is

Volume 9 Issue 2 (2023) 130 https://doi.org/10.18063/ijb.v9i2.659