Biomimetic matrix fabricated by LMP-1 gene-transduced MC3T3-E1 cells for bone regeneration

Biofabrication. 2017 Nov 14;9(4):045010. doi: 10.1088/1758-5090/aa8dd1.

Abstract

Bone healing is regulated by multiple microenvironmental signals provided by the extracellular matrix (ECM). This study aimed to mimic the native osteoinductive microenvironment by developing an ECM using gene-transduced cells. The LIM mineralization protein-1 (LMP-1) gene was transferred to murine pre-osteoblast cells (MC3T3-E1) using lentiviral vectors. Western blotting assay indicated that the MC3T3-E1 cells expressed an increased level of bone morphologic protein-2, -4 and -7 (BMP-2, -4 and -7) after LMP-1 gene transduction. The transduced cells were then seeded into calcined bovine bone scaffolds and cultured for 7, 14, and 21 days to construct ECMs on the scaffolds. The ECM-scaffold composites were then decellularized using the freeze-drying method. Scaffolds without ECM deposition were used as controls. The composites and controls were implanted into critical-sized bone defects created in the distal femurs of New Zealand rabbits. Twelve weeks after the surgery, both microcomputed tomography and histologic results indicated that the 7-day-cell-modified ECM-scaffold composites induced bone regeneration with significantly larger volume, trabecular thickness and connectivity than the controls. However, the 14- and 21-day-cell-modified ECM-scaffold composites triggered sustained inflammation response even at 12 weeks after the surgery and showed less bone ingrowth and integration than their 7-day-cell-modified counterparts. In conclusion, these results highlight the viable gene transfer techniques for manipulating cells in a constructed microenvironment of ECM for bone regeneration. However, the unresolved inflammation relating to the duration of ECM modification needs to be considered.

MeSH terms

  • Animals
  • Base Sequence
  • Biomimetic Materials / chemistry*
  • Bone Morphogenetic Proteins / metabolism
  • Bone Regeneration / physiology*
  • Bone and Bones / diagnostic imaging
  • Bone and Bones / pathology
  • Bone and Bones / physiology*
  • Cattle
  • Cell Differentiation
  • Cell Line
  • Extracellular Matrix / metabolism
  • Genetic Vectors / genetics
  • Genetic Vectors / metabolism
  • LIM Domain Proteins / genetics
  • LIM Domain Proteins / metabolism*
  • Mice
  • Osteoblasts / cytology
  • Osteoblasts / metabolism
  • Prostheses and Implants
  • Rabbits
  • Tissue Engineering
  • Tissue Scaffolds / chemistry
  • X-Ray Microtomography

Substances

  • Bone Morphogenetic Proteins
  • LIM Domain Proteins