Tissue-engineered constructs based on SPCL scaffolds cultured with goat marrow cells: functionality in femoral defects

Abstract

This study aims to assess the in vivo performance of cell-scaffold constructs composed of goat marrow stromal cells (GBMCs) and SPCL (a blend of starch with polycaprolactone) fibre mesh scaffolds at different stages of development, using an autologous model. GBMCs from iliac crests were seeded onto SPCL scaffolds and in vitro cultured for 1 and 7 days in osteogenic medium. After 1 and 7 days, the constructs were characterized for proliferation and initial osteoblastic expression by alkaline phosphatase (ALP) activity. Scanning electron microscopy analysis was performed to investigate cellular morphology and adhesion to SPCL scaffolds. Non-critical defects (diameter 6 mm, depth 3 mm) were drilled in the posterior femurs of four adult goats from which bone marrow and serum had been collected previously. Drill defects alone and defects filled with scaffolds without cells were used as controls. After implantation, intravital fluorescence markers, xylenol orange, calcein green and tetracycline, were injected subcutaneously after 2, 4 and 6 weeks, respectively, for bone formation and mineralization monitoring. Subsequently, samples were stained with Lévai-Laczkó for bone formation and histomorphometric analysis. GBMCs adhered and proliferated on SPCL scaffolds and an initial differentiation into pre-osteoblasts was detected by an increasing level of ALP activity with the culture time. In vivo experiments indicated that bone neoformation occurred in all femoral defects. The results obtained provided important information about the performance of SPCL-GBMC constructs in an orthotopic goat model that enabled future studies to be designed to investigate in vivo the functionality of SPCL-GBMC constructs in more complex models, viz. critical sized defects, and to evaluate the influence of in vitro cultured autologous cells in the healing and bone regenerative process.

Assessing the repair of critical size bone defects performed in a goat tibia model using tissue-engineered constructs cultured in a bidirectional flow perfusion bioreactor

“…In higher strain environments, cellular differentiation favors osteoclasis and chondrogenesis or fibrogenisis. 18 This was not visualized in other study group animals (control six weeks and static six weeks), which can probably be explained by the short time of the weight-bearing of the limb, since during the first two weeks a limb immobilization by a modified RobertJones bandage was applied in the operated limb (of the all animals). However, the stress was not observed in the groups static 12 weeks and bioreactor 12 weeks, due to the mechanical support provided by the SPCL constructs, that supported the load together with the bone fixation device(plate and screw), since the device was loaded with the purpose of compressing the stacked GBMSCs-SPCL constructs.…”

Cell Engineering by the Internalization of Bioinstructive Micelles for Enhanced Bone Regeneration

“…The orthotopic location in vivo is expected to provide more accurate outcomes concerning the influence or local effects of implanted cells or cell scaffold constructs where they were initially designed to be functional [40]. The ulna defect is appropriate for in vivo tests as it does not require further internal or external fixation, which might influence the outcome of the experiment.…”

Undifferentiated human adipose‐derived stromal/stem cells loaded onto wet‐spun starch–polycaprolactone scaffolds enhance bone regeneration: Nude mice calvarial defect in vivo study

“…Although the defects were not completely bridged, new bone was present in the center of the defect, with large areas of matrix and connective tissue formation, confirmed by Masson’s Trichrome staining and representative micro-CT scanning, particularly in SPCL + ASCs explants. Most of the similar studies reported in literature, use stem cells that are pre-differentiated into the osteogenic lineage prior to implantation 22,50–53 . This study demonstrates that non-differentiated ASCs enhance the process of bone regeneration when used in tissue engineering strategies.…”