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

Previous studies have demonstrated the effect of human parathyroid hormone (1-34) (PTH) or strontium-doped hydroxyapatite coating (Sr-HA) on osteoporotic bone implantation. However, reports about effects of PTH plus Sr-HA on bone osseointegration of titanium implants in a state of osteoporosis were limited. This study was designed to investigate the effects of intermittent administration of human parathyroid hormone (1-34) on strontium-doped hydroxyapatite coating (Sr-HA) implant fixation in ovariectomized (OVX) rats. Twelve weeks after bilateral ovariectomy, all animals were randomly divided into four groups including control group, Sr group, PTH group and PTH+Sr group. Forty OVX rats accepted implant insertion in the distal femurs, control group, and PTH group with HA implants and the Sr group and PTH+Sr group with Sr-HA implants. Animals from PTH group and PTH+Sr group then randomly received PTH (60 µg/kg, 3 times a week) until death at 12 weeks. After 12-week healing period, implants from group PTH+Sr revealed improved osseointegration compared with other treatment groups, which is manifested by the exceeding increase of bone area ratio and bone-to-implant contact, the trabecular microarchitecture and the maximal push-out force displayed by tests like histomorphometry, micro-CT, and biomechanics evaluation. These results demonstrated that PTH+ Sr-HA coatings could enhance implant osseointegration in OVX rats, and suggested the feasibility of using this method to improve implant fixation in osteoporotic bone.

Tao ZS ，Zhou WS ，Qiang Z ，Tu KK ，Huang ZL ，Xu HM ，Sun T ，Lv YX ，Cui W ，Yang L ... -  《-》

A comparative study of zinc, magnesium, strontium-incorporated hydroxyapatite-coated titanium implants for osseointegration of osteopenic rats.

Surface modification techniques have been applied to generate titanium implant surfaces that promote osseointegration for the implants in cementless arthroplasty. However, its effect is not sufficient for osteoporotic bone. Zinc (Zn), magnesium (Mg), and strontium (Sr) present a beneficial effect on bone growth, and positively affect bone regeneration. The aim of this study was to confirm the different effects of the fixation strength of Zn, Mg, Sr-substituted hydroxyapatite-coated (Zn-HA-coated, Mg-HA-coated, Sr-HA-coated) titanium implants via electrochemical deposition in the osteoporotic condition. Female Sprague-Dawley rats were used for this study. Twelve weeks after bilateral ovariectomy, all animals were randomly divided into four groups: group HA; group Zn-HA; group Mg-HA and group Sr-HA. Afterwards, all rats from groups HA, Zn-HA, Mg-HA and Sr-HA received implants with hydroxyapatite containing 0%, 10% Zn ions, 10% Mg ions, and 10% Sr ions. Implants were inserted bilaterally in all animals until death at 12 weeks. The bilateral femurs of rats were harvested for evaluation. All treatment groups increased new bone formation around the surface of titanium rods and push-out force; group Sr-HA showed the strongest effects on new bone formation and biomechanical strength. Additionally, there are significant differences in bone formation and push-out force was observed between groups Zn-HA and Mg-HA. This finding suggests that Zn, Mg, Sr-substituted hydroxyapatite coatings can improve implant osseointegration, and the 10% Sr coating exhibited the best properties for implant osseointegration among the tested coatings in osteoporosis rats.

Tao ZS ，Zhou WS ，He XW ，Liu W ，Bai BL ，Zhou Q ，Huang ZL ，Tu KK ，Li H ，Sun T ，Lv YX ，Cui W ，Yang L ... -  《-》

The effects of combined human parathyroid hormone (1-34) and simvastatin treatment on osseous integration of hydroxyapatite-coated titanium implants in the femur of ovariectomized rats.

The effect of human parathyroid hormone 1-34 (PTH) and simvastatin (SIM) alone could promote bone healing in osteoporotic osseous integration of the implant, but there are no reports about the combined use of PTH and SIM for promotion of bone healing around implant in osteoporotic settings still limited. This study aims to investigate effects of PTH+SIM on osseous integration of the implant in OVX rats. Female Sprague-Dawley rats were used for this study. Twelve weeks after bilateral ovariectomy, all animals were randomly divided into four groups: group control; group SIM; group PTH and group PTH+SIM. Afterwards, all OVX rats received hydroxyapatite (HA)-coated titanium rods (external diameter and length are 1.5mm and 20mm) in the femoral medullary canal. Subsequently, the animals from group SIM, group PTH and group PTH+SIM received human parathyroid hormone 1-34 (60μg/kg, three times a week), SIM (5mg/kg daily), or both for 12 weeks. Implants were inserted bilaterally in all animals until death at 12 weeks. The bilateral femurs of rats were harvested for evaluation. All groups increased new bone formation around the surface of titanium rods and push-out force; group PTH+SIM showed the strongest effects on new bone formation and biomechanical strength. Additionally, these are significant difference observed in bone formation and push-out force between groups SIM and PTH. This finding suggests that intermittent administration of PTH or SIM alone has an effect to increase new bone formation on the surface of HA-coated implants in the osteoporotic condition, and the additive effects of combination PTH and SIM on osseous integration of the implant in OVX rats.

Tao ZS ，Zhou WS ，Tu KK ，Huang ZL ，Zhou Q ，Sun T ，Lv YX ，Cui W ，Yang L ... -  《-》

Effects of combined human parathyroid hormone (1-34) and menaquinone-4 treatment on the interface of hydroxyapatite-coated titanium implants in the femur of osteoporotic rats.

Li H ，Zhou Q ，Bai BL ，Weng SJ ，Wu ZY ，Xie ZJ ，Feng ZH ，Cheng L ，Boodhun V ，Yang L ... -  《-》

A comparative study of strontium-substituted hydroxyapatite coating on implant's osseointegration for osteopenic rats.

Tao ZS ，Bai BL ，He XW ，Liu W ，Li H ，Zhou Q ，Sun T ，Huang ZL ，Tu KK ，Lv YX ，Cui W ，Yang L ... -  《-》