99mTc-Methylene diphosphonate （99mTc-MDP） is widely used in clinical settings to detect bone abnormalities. However, the mechanism of 99mTc-MDP uptake in bone is not well elucidated. In this study, we utilized a mou...99mTc-Methylene diphosphonate （99mTc-MDP） is widely used in clinical settings to detect bone abnormalities. However, the mechanism of 99mTc-MDP uptake in bone is not well elucidated. In this study, we utilized a mouse tibia injury model, single-photon emission computed tomography （gamma scintigraphy or SPECT）, ex vivo micro-computed tomography, and histology to monitor 99mTc-MDP uptake in injury sites during skeletal healing. In an ex vivo culture system, calvarial cells were differentiated into osteoblasts with osteogenic medium, pulsed with 99mTc-MDP at different time points, and quantitated for 99mTc-MDP uptake with a gamma counter. We demonstrated that 99mTc-MDP uptake in the injury sites corresponded to osteoblast generation in those sites throughout the healing process. The 99mTc-MDP uptake within the injury sites peaked on day 7 post-injury, while the injury sites were occupied by mature osteoblasts also starting from day 7. ~mTc-MDP uptake started to decrease 14 days post-surgery, when we observed the highest level of bony tissue in the injury sites. We also found that 99mTc-MDP uptake was associated with osteoblast maturation and mineralization in vitro. This study provides direct and biological evidence for 99mTc-MDP uptake in osteoblasts during bone healing in vivo and in vitro.展开更多
Rat calvarial osteoblasts were treated with lanthanum chloride（LaCl3） to explore its effect on the mineral crystalline phase during the process of osteoblast calcification in uitro.The results confirmed that La was ...Rat calvarial osteoblasts were treated with lanthanum chloride（LaCl3） to explore its effect on the mineral crystalline phase during the process of osteoblast calcification in uitro.The results confirmed that La was readily deposited in the mineral component of the matrix.Employing high-resolution transmission electron microscopy and Fourier transform infrared microspectroscopy techniques,we demonstrated that features comparable to dicalcium phosphate dihydrate（DCPD） and octacalcium phosphate,and hydroxyapatite（HAP） were detected in the mineral phases in uitro.Particularly,LaCl3 treatment retarded conversion from DCPD-like phase into HAP during mineralization.In addition,La was introduced in DCPD powder during wet chemical synthesis.When compared with that of La-free DCPD,the dissolution rate of La-incorporated DCPD was lower,thereby leading to a delayed DCPD-to-HAP phase transformation.Thus,it can be concluded that LaCl3 treatment influences the kinetics of inorganic phase transition by decreasing the dissolution rate of DCPD.展开更多
Introduction Mechanotransduction has demonstrated potentials for tissue adaptation in vivo and in vitro. It is well documented that ultrasound,as a mechanical signal,can produce a wide variety of biological effects in...Introduction Mechanotransduction has demonstrated potentials for tissue adaptation in vivo and in vitro. It is well documented that ultrasound,as a mechanical signal,can produce a wide variety of biological effects in vitro and in vivo [1]. As an example,展开更多
基金supported by the Van Andel Research Instituteby a grant to BOW from the NIH/NIAMS (AR053293)
文摘99mTc-Methylene diphosphonate （99mTc-MDP） is widely used in clinical settings to detect bone abnormalities. However, the mechanism of 99mTc-MDP uptake in bone is not well elucidated. In this study, we utilized a mouse tibia injury model, single-photon emission computed tomography （gamma scintigraphy or SPECT）, ex vivo micro-computed tomography, and histology to monitor 99mTc-MDP uptake in injury sites during skeletal healing. In an ex vivo culture system, calvarial cells were differentiated into osteoblasts with osteogenic medium, pulsed with 99mTc-MDP at different time points, and quantitated for 99mTc-MDP uptake with a gamma counter. We demonstrated that 99mTc-MDP uptake in the injury sites corresponded to osteoblast generation in those sites throughout the healing process. The 99mTc-MDP uptake within the injury sites peaked on day 7 post-injury, while the injury sites were occupied by mature osteoblasts also starting from day 7. ~mTc-MDP uptake started to decrease 14 days post-surgery, when we observed the highest level of bony tissue in the injury sites. We also found that 99mTc-MDP uptake was associated with osteoblast maturation and mineralization in vitro. This study provides direct and biological evidence for 99mTc-MDP uptake in osteoblasts during bone healing in vivo and in vitro.
基金supported by the National Natural Science Foundation of China(No.21101008)
文摘Rat calvarial osteoblasts were treated with lanthanum chloride（LaCl3） to explore its effect on the mineral crystalline phase during the process of osteoblast calcification in uitro.The results confirmed that La was readily deposited in the mineral component of the matrix.Employing high-resolution transmission electron microscopy and Fourier transform infrared microspectroscopy techniques,we demonstrated that features comparable to dicalcium phosphate dihydrate（DCPD） and octacalcium phosphate,and hydroxyapatite（HAP） were detected in the mineral phases in uitro.Particularly,LaCl3 treatment retarded conversion from DCPD-like phase into HAP during mineralization.In addition,La was introduced in DCPD powder during wet chemical synthesis.When compared with that of La-free DCPD,the dissolution rate of La-incorporated DCPD was lower,thereby leading to a delayed DCPD-to-HAP phase transformation.Thus,it can be concluded that LaCl3 treatment influences the kinetics of inorganic phase transition by decreasing the dissolution rate of DCPD.
基金supported by the NIH (R01 AR52379 & R01 AR49286),U S Army Medical Research and NSBRI
文摘Introduction Mechanotransduction has demonstrated potentials for tissue adaptation in vivo and in vitro. It is well documented that ultrasound,as a mechanical signal,can produce a wide variety of biological effects in vitro and in vivo [1]. As an example,
