In vivo performance of a novel silk fibroin scaffold for partial meniscal replacement in a sheep model

Abstract

Purpose Due to the negative effects of meniscectomy, there is a need for an adequate material to replace damaged meniscal tissue. To date, no material tested has been able to replace the meniscus sufficiently. Therefore, a new silk fibroin scaffold was investigated in an in vivo sheep model.MethodsPartial meniscectomy was carried out to the medial meniscus of 28 sheep, and a scaffold was implanted in 19 menisci (3-month scaffold group, n = 9; 6-month scaffold group, n = 10). In 9 sheep, the defect remained empty (partial meniscectomy group). Sham operation was performed in 9 animals.ResultsThe silk scaffold was able to withstand the loads experienced during the implantation period. It caused no inflammatory reaction in the joint 6 months postoperatively, and there were no significant differences in cartilage degeneration between the scaffold and sham groups. The compressive properties of the scaffold approached those of meniscal tissue. However, the scaffolds were not always stably fixed in the defect, leading to gapping between implant and host tissue or to total loss of the implant in 3 of 9 cases in each scaffold group. Hence, the fixation technique needs to be improved to achieve a better integration into the host tissue, and the long-term performance of the scaffolds should be further investigated.ConclusionThese first in vivo results on a new silk fibroin scaffold provide the basis for further meniscal implant development. Whilst more data are required, there is preliminary evidence of chondroprotective properties, and the compressive properties and biocompatibility are promising.

Biomechanical characterization of a novel collagen‐hyaluronan infused 3D‐printed polymeric device for partial meniscus replacement

“…To our knowledge, this is the first partial meniscus device to successfully replicate the compressive properties of the native ovine meniscus. Others have achieved less than half of the compressive properties of the native meniscus . CMI and Actifit possess compressive properties of about 25% of ovine meniscus and 26–27% of the human meniscus …”

“…Actifit has exhibited poor survivorship, with 36.4% requiring removal in a recent clinical trial . Other researchers have attempted to develop homogenous, tissue‐engineered scaffolds composed of biologic and/or synthetic materials . However, these scaffolds are limited by their isotropic structure, which do not properly mimic the function of the anisotropic meniscus.…”

Advances in combining gene therapy with cell and tissue engineering-based approaches to enhance healing of the meniscus

“…Different types of meniscal substitutes, such as autologous tissue 81–83 , decellularized allogenic and xenogenic grafts 76,84,85 , collagen grafts 86 , permanent synthetic scaffolds 38 , silk fibroin scaffolds 87,88 , and biodegradable scaffolds based on small intestine submucosa 89 , poly-lactic acid (PLA) or poly-glycolic acid (PGA) 90,91 , have been used in experimental and clinical studies.…”

Dynamic compression of human and ovine meniscal tissue compared with a potential thermoplastic elastomer hydrogel replacement

“…Ultimately, the functionality of both the material used as a replacement or scaffold, as well as the large animal model used for in vivo testing should be considered carefully. A number of synthetic materials have been investigated for meniscal replacements . Limitations with previously reported materials include poor durability, mechanics, and biocompatibility .…”

“…A number of synthetic materials have been investigated for meniscal replacements. [23][24][25][26][27][28][29] Limitations with previously reported materials include poor durability, mechanics, and biocompatibility. [30][31][32] Degradable scaffolds have also been investigated to serve as temporary meniscal replacements but have been shown to have limited mechanical integrity and lead to cartilage damage once tested in vivo.…”