A Novel Rat Tail Needle Minimally Invasive Puncture Model Using Three-Dimensional Printing for Disk Degeneration and Progressive Osteogenesis Research.

Dongdong Xia,Ting Ge,Wenhao Hu,Jin Xiao,Meijun Yan,Junqi Liu,Xiaochuan Wu,Jun Tan,Baiwen Hu,Liang Gao,Xin Yin,Chi Zhang

doi:10.3389/fcell.2021.587399

Abstract

Many studies focused on the annulus fibrosus (AF) injury in rodent tail model for the intervertebral disk degeneration (IDD) research. However, previous studies caused tremendous injury of intervertebral disk (IVD) by penetrating whole disk. This study aimed to build a progressive IDD rodent tail model by a novel device for precise and minimally invasive puncture in AF. A precise puncture device was customized by 3D Printing Technique. 40 rodent tail IVDs were randomly grouped as follows: group A, non-puncture; group B, annulus needle puncture (ANP) for 4 week; group C, ANP for 8 week; and group D, ANP for 12 week. Pre- and post-puncture IVD height on radiographs and IVD signal intensity on T2 magnetic resonance imaging (MRI) were measured. Average bone density (ABD) on the end of coccygeal vertebrae between punctured disk was measured on the radiographs. Hematoxylin and eosin, TUNEL staining methods, immunofluorescence for cleaved-caspas3 and immunohistochemistry for aggrecan and collagen II were performed. Progressively and significantly increasing IVD height loss and degenerative grade were observed following the time points. The ABD was respectively, 81.20 ± 4.63 in group A, 83.93±3.18 in group B, 92.65 ± 4.32 in group C, 98.87 ± 6.69 in group D. In both group C and group D, there were significant differences with group A. In histology, increasing number of AF cells was noted in group B. In both group C and D, the fissures in AF were obviously observed, and a marked reduction of AF cells were also observed. In all ANP groups, there were significant decrease in number of NP cells, as well as aggrecan and collagen II contents. TUNEL assay showed cellular apoptosis were stimulated in all puncture group, especially in group D. A progressive IDD rat model could be standardly established by the micro-injury IVD puncture using a novel 3D printing device. This animal model provided a potential application for research of progressive hyperosteogeny following IDD development.

Highlights

Intervertebral disk degeneration (IDD) is a common pathophysiological condition in humans affecting the intervertebral disc (IVD), which can include height decrease, disk herniation, and vertebral osteogenesis, due to its implication in causing lower back pain (Deyo and Weinstein, 2001; Alini et al, 2008)
A new method of annulus needle puncture (ANP) rabbit model was reported to establish a reproducible animal model of disk degeneration that could be detected in slowly progressive changes by magnetic resonance imaging (MRI), radiographs, and histology (Masuda et al, 2005; Sobajima et al, 2005)
The results (Figure 2A) demonstrated that the disk width progressively narrowed over time, and no disk width changes were observed in the adjacent disk of the punctured IVDs

Summary

Introduction

Intervertebral disk degeneration (IDD) is a common pathophysiological condition in humans affecting the intervertebral disc (IVD), which can include height decrease, disk herniation, and vertebral osteogenesis, due to its implication in causing lower back pain (Deyo and Weinstein, 2001; Alini et al, 2008). A new method of annulus needle puncture (ANP) rabbit model was reported to establish a reproducible animal model of disk degeneration that could be detected in slowly progressive changes by magnetic resonance imaging (MRI), radiographs, and histology (Masuda et al, 2005; Sobajima et al, 2005). With minimal risk of damage to surrounding structures and minimal interference with normal physiological function, the rat tail discs (RTD) were more suitable and feasible for the ANP method to induce IDD (Han et al, 2008; Issy et al, 2013; Grunert et al, 2014; Liao, 2016; Cunha et al, 2017). Most of the reported studies used the 18G (diameter = 1.2 mm) or 21G (diameter = 0.8 mm) needle to puncture the RTD, which lacked the meaning of progressive degeneration research due to great injury to the IVD. There was no uniform standard for the depth of the puncture

Objectives

Results

Conclusion