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International Journal of Bioprinting Bioprinting hearing loss treatment

central auditory pathways, leading to difficulties in biomaterials, but high shear stress during extrusion may
sound perception or nerve signal transmission. Mixed cause cell damage and death. 14,15 Jetting-based bioprinting
hearing loss combines characteristics of both conductive dispenses small droplets of bioink onto a substrate in
and sensorineural impairments, posing a multifaceted a non-contact manner, offering high resolution and
treatment dilemma. precision; however, controlling droplet impacts velocity,
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Timely identification and intervention are imperative and volume is essential for maintaining high cell viability.
for successful hearing loss management. Effective Vat photopolymerization-based bioprinting, also
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treatments for conductive hearing loss may include the known as stereolithography, uses light to selectively cure
use of anti-inflammatory drugs, correction of ear canal photosensitive bioink in a vat through a layer-by-layer
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malformations, removal of lesions within the ear canal, fashion. While this method achieves high resolution and
tympanic membrane repair, and reconstruction of the complex geometries, the photopolymerization process may
ossicular chain, among other interventions. In cases lead to cytotoxicity, and studies have noted its impact on
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of sudden sensorineural hearing loss, drug therapy can the mechanical properties of fabricated tissue scaffolds. 12
effectively restore auditory function, regardless of the extent The essential steps in 3D bioprinting encompass
of the loss. Furthermore, the utilization of hearing aids or the visualization and generation of the tissue model,
cochlear implants in conjunction with speech perception the selection of suitable biomaterials and cells, and the
training has been associated with the maintenance and construction of the tissue structure. These processes rely
enhancement of residual hearing. Effective treatments for on the utilization of computer-aided design programs,
severe hearing loss caused by various serious conditions which play a critical role in converting intricate biological
remain elusive. Conditions such as long-term traumatic tissue models into digital representations, guiding the
hearing loss, hereditary hearing loss, presbycusis, and bioprinting procedure with accuracy. The bioink utilized
idiopathic sudden sensorineural hearing loss are often consists of diverse cells, biomaterials, and bioactive
considered irreversible and do not typically respond to molecules, while the bioprinter, crucial for the reliability
conventional medical therapies. 5 and excellence of the results. The influence of printing on
Bioprinting, also referred to as three-dimensional cell viability is a critical aspect to consider in bioprinting.
(3D) bioprinting, is a prominent tissue engineering High shear stress during extrusion-based bioprinting can
method that has emerged as a sophisticated form of lead to cell damage and death. 14,15 Similarly, in jetting-
additive biomanufacturing derived from conventional 3D based bioprinting, the impact of droplets on the substrate
printing. This innovative technology has the capability to can cause mechanical stress on the cells, affecting their
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create cells, tissues, and organs with intricate structures viability. In vat photopolymerization-based bioprinting,
and functions, without relying on natural regeneration the photopolymerization process can cause cytotoxicity,
processes. The swift progress of 3D printing has resulted affecting cell behavior. 11,17 Possible strategies for improving
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in notable advancements in regenerative medicine, offering cell vitality include the following: firstly, the formulation
potential solutions for repairing or substituting damaged of bioinks and printing parameters such as temperature,
tissues that necessitate meticulous control during the pressure, and printing speed can be optimized to
regeneration process. In recent years, this methodology enhance the cells’ survival environment and vitality. 18–20
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has proven to be groundbreaking for individuals who Polyvinylpyrrolidone (PVP)-based bioinks have been
have experienced enduring injuries or sustained long- shown to improve cell viability and homogeneity during
term irreversible impairments. Furthermore, bioprinting jetting-based bioprinting. 20,21 Secondly, the growth and
methodologies are now employed in pharmaceutical differentiation capabilities of cells can be enhanced by
screening and the creation of tailored treatments or altering the composition and structure of hydrogels, such
precision medicine. These advancements have the potential as by adding nutrients and growth factors, or by creating
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to enhance drug development and the efficacy of precision a microenvironment more conducive to cell growth.
medicine approaches. 9,10 Finally, cell vitality and function can be improved by
introducing macromolecular crowding to simulate the
According to American Society for Testing and natural environment of cells in the body. Research dating
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Materials (ASTM) standards, bioprinting techniques back to 2013 documented the successful production
can be broadly classified into three categories: extrusion- of various systemic organs, including hearts, articular
based, jetting-based, and vat photopolymerization-based cartilage, livers, and ears (see Figure 1), through the
methods. 11–13 Extrusion-based bioprinting continuously utilization of 3D bioprinting technology. 24–26
deposits bioink, a mixture of cells and biomaterials,
through a nozzle by applying mechanical pressure. This In light of the pivotal significance of bioprinting
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method supports high cell density and a wide range of technology, this paper aims to investigate its novel
Volume 10 Issue 4 (2024) 105 doi: 10.36922/ijb.3497