Immunohistochemical evaluation after Sr-enriched biphasic ceramic implantation in rabbits femoral neck: comparison of seven different bone conditions

J Mater Sci Mater Med. 2018 Jul 20;29(8):119. doi: 10.1007/s10856-018-6124-7.

Abstract

Strontium (Sr) has shown effectiveness for stimulating bone remodeling. Nevertheless, the exact therapeutic values are not established yet. Authors hypothesized that local application of Sr-enriched ceramics would enhance bone remodeling in constant osteoporosis of rabbits' femoral neck bone. Seven different bone conditions were analyzed: ten healthy rabbits composed a control group, while other twenty underwent ovariectomy and were divided into three groups. Bone defect was filled with hydroxyapatite 30% (HAP) and tricalcium phosphate 70% (TCP) granules in 7 rabbits, 5% of Sr-enriched HAP/TCP granules in 7, but sham defect was left unfilled in 6 rabbits. Bone samples were obtained from operated and non-operated legs 12 weeks after surgery and analyzed by histomorphometry and immunohistochemistry (IMH). Mean trabecular bone area in control group was 0.393 mm2, in HAP/TCP - 0.226 mm2, in HAP/TCP/Sr - 0.234 mm2 and after sham surgery - 0.242 mm2. IMH revealed that HAP/TCP/Sr induced most noticeable increase of nuclear factor kappa beta 105 (NFkB 105), osteoprotegerin (OPG), osteocalcin (OC), bone morphogenetic protein 2/4 (BMP 2/4), collagen type 1α (COL-1α), interleukin 1 (IL-1) with comparison to intact leg; NFkB 105 and OPG rather than pure HAP/TCP or sham bone. We concluded that Sr-enriched biomaterials induce higher potential to improve bone regeneration than pure bioceramics in constant osteoporosis of femoral neck bone. Further studies on bigger osteoporotic animals using Sr-substituted orthopedic implants for femoral neck fixation should be performed to confirm valuable role in local treatment of osteoporotic femoral neck fractures in humans.

MeSH terms

  • Animals
  • Biocompatible Materials / chemistry
  • Bone Regeneration / drug effects*
  • Bone Remodeling
  • Bone Substitutes / chemistry*
  • Calcium Phosphates / chemistry
  • Ceramics / chemistry*
  • Durapatite / chemistry
  • Female
  • Femur / chemistry*
  • Femur Head / pathology
  • Immunohistochemistry
  • Inflammation
  • Osteoporosis / therapy*
  • Osteoprotegerin / chemistry
  • Rabbits
  • Strontium / chemistry*

Substances

  • Biocompatible Materials
  • Bone Substitutes
  • Calcium Phosphates
  • Osteoprotegerin
  • Durapatite
  • tricalcium phosphate
  • Strontium