Muscle extracellular matrix scaffold is a multipotent environment

Abstract

The multipotency of scaffolds is a new concept. Skeletal muscle acellular scaffolds (MAS) implanted at the interface of Tibialis Anterior/tibial bone and masseter muscle/mandible bone in a murine model were colonized by muscle cells near the host muscle and by bone-cartilaginous tissues near the host bone, thus highlighting the importance of the environment in directing cell homing and differentiation. These results unveil the multipotency of MAS and point to the potential of this new technique as a valuable tool in musculo-skeletal tissue regeneration.

Keywords: ECM scaffold; bone; cartilage; skeletal muscle; tissue engineering.

Figure 1

Macroscopic and histological evaluation of scaffold transplantation between Tibialis Anterior (TA) muscle and tibia bone 21 days after transplantation. a) Mechanical detachment of TA muscle from tibia bone before the implant. b) The graft 21 days after transplantation. c) Tibia bone after graft removal 21 days after transplantation. d) Untreated tibia bone after TA removal. e) Hematoxylin and eosin staining (H&E) for whole graft reconstruction shows infiltration by mononucleated cells in the graft and the presence of regenerating myofibers at the edge between the muscle and the graft. The inset represents a micrograph at higher magnification/resolution obtained with a 40x lens. Scale bar = 50 μm. f) Alizarin red staining for whole graft reconstruction highlights the presence of calcified areas in the graft. g) and h) Toluidine blue and Alcian staining, respectively, for whole graft reconstruction demonstrate cartilage formation in the graft. Since the images are derived from serial sections, the rectangles indicate corresponding areas in the graft. The insets represent a micrograph at higher magnification/resolution obtained with a 20x lens. Scale bar = 100 μm.

Figure 2

Macroscopic and histological evaluation of scaffold transplantation between masseter (M) and mandible bone (MB) 21 days after transplantation. a) Mechanical detachment of masseter muscle from mandible bone before the implant. b) External surface appearance 21 days after transplantation. c) The graft 21 days after transplantation and d) the collected graft. e) H&E staining for whole graft reconstruction shows the area of the graft infiltrated by mononucleated cells and the presence of regenerating myofibers at the edge between the muscle and the graft. The inset represents a micrograph at higher magnification/resolution obtained with a 40x lens. Scale bar = 50 μm f) The same area stained with Alizarin red highlights the presence of calcified areas in the graft. g) and h) Toluidine blue and Alcian staining, respectively, for whole graft reconstruction show cartilage formation in the same area of the graft. Since the images are derived from serial sections, the rectangles indicate corresponding areas in the graft. The insets represent a micrograph at higher magnification/resolution obtained with a 20x lens. Scale bar = 100 μm.