AccScience Publishing / IJB / Online First / DOI: 10.36922/ijb.5021
RESEARCH ARTICLE
Early Access

Proof of concept of using an in-house bioprinter to replicate an intervertebral disc

Emmaëlle Carrot1 Perrine de Villemagne2 Paul Humbert1 Sébastien Grastilleur1 Benoit Rosa2 Boris Halgand1 Yoan Le Guennec1 Johann Clouet1 Vianney Delplace1 Pierre Weiss1 Franck Halary3 Jean-Yves Hascoët2 Marion Fusellier1 Luciano Vidal2,4 Jérôme Guicheux1 Catherine Le Visage1*
Submitted: 10 October 2024 | Accepted: 9 December 2024 | Published: 10 December 2024
© 2024 by the Author(s). This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution 4.0 International License ( https://creativecommons.org/licenses/by/4.0/ )
Abstract

The intervertebral disc, a fibro-cartilaginous structure, contains a gelatinous core (Nucleus pulposus) surrounded by collagen fiber lamellae (Annulus fibrosus). Intervertebral disc degeneration leads to a debilitating disorder, and new treatments are currently being developed. Unfortunately, the conventional monolayer in vitro models fail to predict the clinical efficacy of novel therapies accurately. Here, we report a bioprinted construct that mimics the macroscopic and microscopic architecture of the intervertebral disc. First, a 3D model was created from a histological section of a sheep lumbar intervertebral disc. The printability of the ink, gelatin (7% w/v), alginate (0.6% w/v), and hyaluronic acid (0.2% w/v) was optimized by varying the printing pressure (70-110 kPa), printing speed (2-10 mm/s) and nozzle type (needle or tip). Nucleus Pulposus and Annulus Fibrosus cells, harvested from four-month-old lambs, were bioprinted (5 × 105 cells/mL) using an in-house extrusion bioprinter. Cell viability (Live/Dead assay), shape (actin immunostaining), distribution (confocal microscopy), and matrix synthesis (immunostaining) were evaluated after 21 days of culture. We used a parametric study to quantify and optimize the factors (pressure, printing speed, nozzle type) influencing the filament width. The 3D construct exhibited fidelity to the initial design and maintained stability in length, width, and height for 21 days. Fluorescent labeling confirmed the Nucleus Pulposus and Annulus Fibrosus cell distribution in each tissue, replicating the native intervertebral disc structure. We also evidenced cell viability and collagen type 1 synthesis. This bioprinted construct offers a promising alternative to current in vitro models, potentially enabling more relevant preclinical evaluations.

Keywords
3D bioprinting
Hydrogel
In-house extrusion bioprinter
In vitro 3D model
Gelatin
Hyaluronic acid
Alginate
Funding
This study was supported by the RFI Bioregate program of Pays de la Loire Region within the framework of the 4D-BIODIV project, the European Commission's Horizon 2020 funding program for the iPSpine project [grant number 825925], the EXCELLDISC project (ANR-19-CE18-0020-01) and the INDEED project (ANR-19-CE06-0028-02).
Conflict of interest
The authors declare they have no competing interests.
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International Journal of Bioprinting, Electronic ISSN: 2424-8002 Print ISSN: 2424-7723, Published by AccScience Publishing