Biomechanical, structural and biological characterisation of a new silk fibroin scaffold for meniscal repair

Abstract

Meniscal injury is typically treated surgically via partial meniscectomy, which has been shown to cause cartilage degeneration in the long-term. Consequently, research has focused on meniscal prevention and replacement. However, none of the materials or implants developed for meniscal replacement have yet achieved widespread acceptance or demonstrated conclusive chondroprotective efficacy.A redesigned silk fibroin scaffold, which already displayed promising results regarding biocompatibility and cartilage protection in a previous study, was characterised in terms of its biomechanical, structural and biological functionality to serve as a potential material for permanent partial meniscal replacement. Therefore, different quasi-static but also dynamic compression tests were performed. However, the determined compressive stiffness (0.56 ± 0.31 MPa and 0.30 ± 0.12 MPa in relaxation and creep configuration, respectively) was higher in comparison to the native meniscal tissue, which could potentially disturb permanent integration into the host tissue. Nevertheless, µ-CT analysis met the postulated requirements for partial meniscal replacement materials in terms of the microstructural parameters, like mean pore size (215.6 ± 10.9 µm) and total porosity (80.1 ± 4.3%). Additionally, the biocompatibility was reconfirmed during cell culture experiments. The current study provides comprehensive mechanical and biological data for the characterisation of this potential replacement material. Although some further optimisation of the silk fibroin scaffold may be advantageous, the silk fibroin scaffold showed sufficient biomechanical competence to support loads already in the early postoperative phase.

Meniscal Replacement With a Silk Fibroin Scaffold Reduces Contact Stresses in the Human Knee

“…However, meniscotibial peak contact pressure was about twice as high compared with the intact condition. The reason might be that under an applied load of only 200 N, most of the load was transferred through the scaffold, probably due to its previously demonstrated high stiffness . This effect was not present under high loads of 2,000 N, when the implant was more compressed and consequently loading was more pronounced on the tibiofemoral cartilage in areas close to the joint midline.…”

“…Silk fibroin implants (FibroFix™; Orthox Ltd.) were manufactured from Bombyx mori silkworm silk as described previously . In brief, silk fibroin fibers were dissolved in lithium bromide and processed into a porous matrix.…”

“…A silk fibroin scaffold (FibroFix™; Orthox Ltd., Abingdon, UK) was previously developed and investigated in several in vitro and in vivo studies . The in vivo performance of the first generation of silk fibroin scaffolds was evaluated in a partial meniscal defect in the ovine model .…”

Parathyroid hormone (1-34) promotes the effects of 3D printed scaffold-seeded bone marrow mesenchymal stem cells on meniscus regeneration

“…Second, BMSCs often undergo terminal differentiation during chondrogenesis, which hampers the regenerative e cacy of tissue engineering [12,13]; this limitation needs to be addressed when using BMSCs as seed cells for meniscus tissue engineering. Furthermore, although tissueengineered meniscus transplantation can promote the recovery of knee joint function, it also causes different degrees of damage to knee cartilage and subchondral bone [14,15].…”

Degradation Behavior of Silk Fibroin Biomaterials - A Review

“…Various forms of materials made of fibroin and sericin such as films, hydrogels, particles, and fibers [19][20][21] have been developed through several methods such as electrospinning [22], Electron-beam lithography [23,24], printing [25][26][27][28], and photolithography [29,30]. The latter method is the most interesting for compatible biomechanics [31][32][33][34][35].…”