Decellularisation of human meniscus tissue using sodium dodecyl sulphate (SDS): Preserving biomechanical integrity for scaffold-based meniscal repair

Abstract

Purpose: Meniscal tears are common knee injuries and a major risk factor for secondary osteoarthritis. Recently, there has been a paradigm shift toward meniscal preservation, reflecting the meniscus's vital role. In this context, tissue engineering approaches such as the development of meniscal scaffolds have gained attention. However, to reduce the immune response and improve biocompatibility, decellularization of allografts, while preserving the histoarchitectural and meniscal properties, is essential. The current study aimed to evaluate the effectiveness of decellularization and its impact on the biomechanical properties of the human meniscus.

Methods: Twenty-one human meniscus specimens were collected between July and December 2023 during total knee arthroplasty. Preoperative MRI was performed to verify meniscal integrity. The specimens were decellularized using a sodium dodecyl sulphate (SDS) protocol and compared to native meniscus samples in terms of cell count, assessed through hematoxylin and eosin staining, and biomechanical properties, specifically Young's modulus, measured using a universal testing machine (Zwick Z010).

Results: The cell count in the decellularized menisci was 11 cells/mm² (SD = 13; 95% CI: 2-20), representing a significant reduction compared to the native meniscus samples, which had a cell count of 111 cells/mm² (SD = 42; 95% CI: 81-141; p < 0.01). Young's modulus of elasticity was 35.3 versus 36.8 MPa in the anterior region (p = 0.8), 32.6 versus 35.6 MPa in the central region (p = 0.7) and 36.5 versus 35.8 MPa in the posterior region (p = 0.9) for native versus decellularized samples, respectively.

Conclusions: This study demonstrated that the modified SDS-based decellularization protocol effectively decellularizes the human meniscus. Moreover, the decellularized tissue retained biomechanical properties comparable to those of native meniscus tissue. Tissue decellularization is a promising technique in regenerative medicine, enabling the use of scaffolds for tissue repair, particularly in applications such as meniscus transplantation following meniscectomy.

Level of evidence: Level III, controlled laboratory study.

Keywords: compressive biomechanical properties; decellularization; knee; meniscus tissue engineering; scaffolds.

Figure 1

Standardised dissected human meniscus specimen showing a medial meniscus sample on a 3D printed carrier.

Figure 2

Anatomy of medial and lateral meniscus samples before freezing with comparison of length (a), width (b) and thickness (c) in mm.

Figure 3

Dead‐live assays of medial meniscus samples validating vital cells (green) after sample collection. The green fluorescent Calcein‐AM shows intracellular esterase activity in the central meniscal regions, thus confirming the presence of vital cells. In contrast red fluorescent Ethidium‐Homodimer‐1, representing avital connective tissue, was shown in some outer soft tissue.

Figure 4

(a) Number of cells/mm² in native and decellularised human meniscus. (b) Hematoxylin and eosin (H&E) staining of a native meniscal section of a medial right meniscus with (c) the nuclei stained blue, while the extracellular matrix and cytoplasm appeared pink, allowing for the quantification of cells within the tissue sections. (d) and (e) Show decellularized sections of a medial right meniscus.