Treatment study of distal femur for parathyroid hormone (1–34) and β-tricalcium phosphate on bone formation in critical size defects in rats

Abstract

The objective of this study was to evaluate local bone formation following systemic administration of parathyroid hormone (1-34), a surgically implanted synthetic β-tricalcium phosphate bone biomaterial serving as a matrix to support new bone formation. Twelve weeks after bilateral ovariectomy, all rats underwent bone defect in the distal femurs, and β-tricalcium phosphate was implanted into critical sized defects. After defect operation, all animals were randomly divided into four groups and received following subcutaneous injections until death at four and eight weeks: sham rats (group ST); sham rats + parathyroid hormone, 30 µg/kg, three times a week (group SPT); OVX rats (group OT); and OVX rats + parathyroid hormone (group OPT). The distal femurs of rats were harvested for evaluation. The treatment group demonstrating the highest levels of new bone formation was the defects treated with parathyroid hormone as assessed by micro-computed tomography, biomechanical strength, and histological analysis for sham rats. Furthermore, parathyroid hormone showed a stronger effect on accelerating the degradation of β-tricalcium phosphate. Osteoporosis can limit the function of parathyroid hormone and/or β-tricalcium phosphate. The results from our study demonstrate that combination of parathyroid hormone and β-tricalcium phosphate brings better effect to bone tissue repair in non-osteoporosis and/or osteoporosis status.

Local administration with silymarin could increase osseointegration of hydroxyapatite-coated titanium implants in ovariectomized rats

“…32 Several previous studies have investigated the influence of osteoporosis on bone healing using OVX rats as an experimental model; this is a well-studied method that simulates the changes in postmenopausal women, and needs an average of three months for the osteopenic condition to onset. 30,33–35 As expected, OVX resulted in a significant decrease in the femoral metaphysic BMD after three months. Femoral metaphysis was chosen as the implant site because in OVX rats, cancellous bone mass in the metaphyseal region of long bones is rapidly reduced and it is large enough in rats to allow implantation, which indicated that this was a suitable condition as a model of osteoporosis.…”

Intermittent administration of human parathyroid hormone (1–34) increases fixation of strontium-doped hydroxyapatite coating titanium implants via electrochemical deposition in ovariectomized rat femur

“…In the experiments conducted, OVX rat was used as an animal model. 22,23 In 3-month-old rats, the effect of OVX on their skeletons was manifested in 12 weeks or less, and the characteristics of the bone loss are mostly similar to those in an aged rat model. Also, in the present experiment, a remarkable decrease in trabecular bone volume was histologically noted in the distal femur of rats at 12 weeks after OVX, which indicated that this was a suitable condition as a model of osteoporosis.…”

“…Forty-five rats were subject to bilateral ovariectomization (OVX), and the surgical procedures were reported in our previous studies. 22,23 Twelve weeks after bilateral ovariectomy ( N = 45) or Sham operation ( N = 5), 5 OVX rats were randomly selected and the 5 sham-operated ones were euthanized. The distal femurs were harvested for bone mineral density (BMD), micro-computed tomography (micro-CT), and histological evaluation to confirm the establishment of osteoporosis.…”

The effect of depression on fracture healing and osteoblast differentiation in rats

“…Once the successful establishment of the depression model was confirmed by behavior evaluation, 10 rats from each group was collected to establish the femur defect model according to procedures as previously described. 8 Briefly, each rat was given a general anesthetic through an intravenous administration of chloral hydrate (10%, 5.0–7.5 mL/kg). Then, a 1.5 cm incision was made to expose the genu after shaving and disinfection.…”