Use of an intramedullary in vivo model to study bone formation and maintenance in ceramic porous domains

Abstract

Tissue ingrowth, differentiation, and osteogenesis in a porous bioinert bioceramic were studied using an intramedullary model. Pure alumina tubes (1.3 mm outer diameter, 0.6 mm inner diameter, 15 mm length) were implanted in the femoral medullary canal of young female rats for 4, 6, 8, 12, and 16 weeks. Tissues present within each tube were characterized by histology and quantified by histomorphometry. A tissue front consisting of undifferentiated mesenchymal cells, fibrovascular tissue, osteoid, woven bone, and marrow penetrated the tube from both ends. Behind the front, woven bone remodeled to produce a thin layer of lamellar bone that lined the tube walls the entire distance to the tube ends and enclosed a marrow-filled lumen. The front was considered to represent the differentiation cascade from mesenchymal cells to fibrovascular tissue to osteoid to woven bone and marrow to lamellar bone and marrow. The fronts advanced into the tube with time such that, by 16 weeks, they were close to meeting or had met. In several instances, the tube was completely lined with a thin layer of mature lamellar bone continuous between the two ends and enclosing marrow. This configuration was considered to be the final equilibrium of tissues within the tube.

The Effect of Bioceramic Surface Chemistry on Osteogenic Cell and Healing Bone

“…Furthermore, chemical composition in Alumina tubes surgically inserted into femoral canals of rats significantly changed the osteogenic affinity index when doped with Cr (lower) or Si (higher) and enhanced osteogenesis and osseous maturation when doped with Mn and Ca alumina tubes at 12 weeks [11].…”

Effect of silicon doping on bone formation within alumina porous domains

“…1 Tissue ingrowth and differentiation within cylindrical tubes (15-mm length, 1.3-mm outer diameter, 0.6-mm internal diameter) of pure alumina implanted in the medullary canal of rats were quantified by histological and histomorphometric analyses as a function of time for up to 16 weeks. This model was used to evaluate the effect of doping alumina with Ca, Cr, or Mn on bone formation within the tube structure.…”

Preparation of β-Tricalcium Phosphate Containing Silica by CO₂-Laser-Irradiation

“…Doping with some metal ions such as Sr, Co or Ni to ceramics plays an important role in the initiation of bone formation [2][3]. In addition, doping with Ca, Cr, Mn and Zn elements are essential to normal growth and metabolism of skeletal tissue in vertebrates [4][5][6][7]. It was postulated that their incorporation into the bioinert alumina ceramics influences the tissue response at the boneceramic interface.…”