Laser micro‐ablation of fibrocartilage tissue: Effects of tissue processing on porosity modification and mechanics

Abstract

The temporomandibular joint disk (TMJd) is an extremely dense and avascular fibrocartilaginous extracellular matrix (ECM) resulting in a limited regenerative capacity. The use of decellularized TMJd as a biocompatible scaffold to guide tissue regeneration is restricted by innate subcellular porosity of the ECM that hinders cellular infiltration and regenerative events. Incorporation of an artificial microporosity through laser micro-ablation (LMA) can alleviate these cell and diffusion based limitations. In this study, LMA was performed either before or after decellularization to assess to effect of surfactant treatment on porosity modification as well as the resultant mechanical and physical scaffold properties. Under convective flow or agitation schemes, pristine and laser ablated disks were decellularized using either low (0.1% w/v) or high (1% w/v) concentrations of sodium dodecyl sulfate (SDS). Results show that lower concentrations of SDS minimized collagen degradation and tissue swelling while retaining its capacity to solubilize cellular content. Regardless of processing scheme, laser ablated channels incorporated after SDS treatment were relatively smaller and more uniform than those incorporated before SDS treatment, indicating an altered laser interaction with surfactant treated tissues. Smaller channels correlated with less disruption of native biomechanical properties indicating surfactant pre-treatment is an important consideration when using LMA to produce artificial porosity in ex vivo derived tissues. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1858-1868, 2018.

Decellularized extracellular matrix scaffolds: Recent trends and emerging strategies in tissue engineering

“…Second, after perfusion, the intact and intricate vascular network, the vital construction of the whole organ, is maintained, including portal vein, artery inflow, and venous outflow, which is essential for the transportation of nutrition and oxygen within organs/tissues [ 5 , 57 , 58 ]. However, perfusion requires additional hardware and complex setup for flow control, such as an infusion/withdrawal syringe pump and pressure transducer [ [59] , [60] , [61] ].…”

“…As an optimal physical way to decellularize, the utilization of immersion and agitation owns plenty of advantages. First, using dynamic immersion and agitation can attain a more homogeneous detergent exposure than static decellularization, and achieve a better decellularization effect with less exposure time to aggressive decellularization agents [ 60 , 66 ]. Second, this method does not significantly affect the ECM surface structure, collagen structure and integrity, mechanical strength, and GAG content [ 56 , [66] , [67] , [68] , [69] ].…”

“…The concentration of SDS plays a critical role in the decellularization process. The higher concentration of SDS results in lower remained DNA content and reduced mechanical strength in the dECM scaffolds, while the lower concentration of SDS leads to more retention of collagen, less denaturation of ECM proteins and increased cytotoxic effects with more cellular remnants [ 29 , 60 , 61 , 65 , 103 ]. However, due to interrupting protein-protein interactions, ionic detergents have a harmful impact on ECM structures and bioactive components [ 48 , 51 , 61 , 103 , 104 ].…”

Tissue Engineering for the Temporomandibular Joint

“…Thus, the natural motion of the TMJ would not be possible using this method. Porcine TMJ discs were decellularized and subsequently made porous by laser-ablation to increase hydraulic conductivity [107,108] . The goal of the microporation was to improve cell adhesion to the scaffold and increase cell density throughout the core of the scaffold.…”

Biological Treatments for Temporomandibular Joint Disc Disorders: Strategies in Tissue Engineering

“…Laser micro ablation was also evaluated to understand whether it should be performed before or after decellularization. It was concluded that it should be done afterward, since it presents smaller and more uniform holes, being related to a lesser alteration of the biomechanical properties [121].…”