[In vivo osteogenic evaluation of titanium implants with strontium loaded nanotubes].

Objective: To evaluate the in vivo osteogenic activity of titanium implants with strontium loaded TiO2 nanotubes (NTSr). Methods: The strontium loaded titanium nanotubes were formed on pure titanium implants through anodization and hydrothermal treatment, and the unmodified titanium (Control) and sheer TiO2 nanotubes (NT) were set to be control groups and treatment group. Inductively coupled plasma mass spectrometry (ICP-MS) was used to evaluate the Sr release at 28 days. Field emission scanning electron microscopes (FE-SEM) was used to view the micro-topography, atomic force microscope was used to exam the surface roughness, and nano-indenter was used to evaluate the hardness of three groups (n=3). Three groups of implant samples were inserted into the distal femoral metaphysis of New Zealand rabbits (n=4 at each time point). After 4 weeks and 12 weeks, samples were harvested. Micro-CT scanning, immunofluorescent and histological examinations were carried out. Results: The strontium ions could be released slowly for at least 28 days [the Sr concentration at 28 Day was (2.6±1.5) ng/ml]. NTSr coating exhibited a nanoscale tube array (the diameter was about 70 nm), and the surface roughness of implant was increased with the nanobube coating [Control (34.8±5.3) nm, NT (66.2±4.3) nm, NTSr (85.7±10.6) nm, F=37.59, P<0.001]. The surface roughness (Ra) of NT and NTSr groups was higher than the control group (P<0.05). Comparing to Control implants, NTSr implants exhibited a better osteogenic ability [the bone volume/total volume (BV/TV) value was Control (24.7±1.1)% vs. NTSr (37.7±1.9)% at 4 weeks (P<0.05), and Control (40.7±0.9)% vs. NTSr (51.9±2.1)% at 12 weeks (P<0.05)]. The fluorescent examination revealed that NTSr coating can also accelerated the generation of new bone tissue (bone tissue area% labelled by alizarin red at day 7 was Control (19.2±2.9)% vs. NT (35.4±3.7)% vs. NTSr (40.9±0.9)% (F=42.74, P<0.01). The results in the NT and NTSr group were statistically higher than that in the control group (P<0.05). Conclusions: The strontium loaded TiO2 nanotubes can enhance new bone formation around titanium implants.

[Water sorption and hygroscopic changes of five core buildup composite resins].

Objective: To evaluate water sorption and hygroscopic dimensional changes of five core buildup composite resins, and to provide references for material modification on water sorption. Methods: Five commercial core buildup materials (group A: Smart Dentin Replacement(TM); group B: NanoFil; group C: ParaCore(TM); group D: LuxaCore Z; group E: EmbraceCore(TM) Resin Cement) were fabricated to disk-shaped specimens: (15.0±0.1) mm diameter, (2.0±0.1) mm thickness (n=10). Specimens were thoroughly irradiated with curing lights. The initial mass in air was recorded, and the initial mass in deionized water was recorded. Five specimens of each group were immersed in deionized water for 28 d. They were weighed as a function of different immersion time (1, 2, 3, 4, 5, 6, 7, 14, 28 d). The mass in air was recorded, and the displayed mass in deionized water was recorded. Archimedes' principle was applied to calculate the dimensional changes. The other five specimens of each group were stored in artificial saliva and were tested by the same methods. Results: All specimens gained weight and hygroscopic changes during 28 d immersion. When stored in deionized water, the apparent mass change of group A [(10.6±0.9) µg/mm(3)] and the dimensional change of group A [(0.39±0.10)%] were the lowest, while the mass change of group E [(48.0±0.2) µg/mm(3)] and the dimensional change of group E [(3.16±0.13)%] were the highest (P<0.05). In artificial saliva, the lowest apparent mass change was found in group A [(11.8±1.0) µg/mm(3)] while the highest change was found in group E [(47.4±3.5) µg/mm(3)] (P<0.05). The lowest dimensional change was found in group C [(0.37±0.09)%] and the highest was found in group E [(3.07±0.19)%] in artificial saliva (P<0.05). Conclusions: Water sorption and dimensional changes vary in immersion fluids with different osmotic pressure. Water sorption and dimensional changes of core buildup composite resins are highly correlated with test materials in both of the deionized water and artificial saliva.

Inconsistency between manganese superoxide dismutase expression and its activity involved in the degeneration of recognition function induced by chronic aluminum overloading in mice.

Manganese (Mn) superoxide dismutase (SOD) is mainly located in mitochondrial matrix and is responsible for scavenging about 80% free radicals from oxidative and phospharylative process in mitochondria. It was reported that the insufficiency of Mn SOD expression or activity was connected to the development of neurodegenerative diseases. In this article, we investigated the time course related to the changes of Mn SOD expression and its activity from mouse brain as well as the recognition dysfunction in chronic aluminum (Al) overloading mice. Aluminum gluconate solution (equal to Al 400 mg/kg) was given to mice once a day, 6 days per week for 12 weeks via intragastric gavage. The learning and memory function, malondialdehyde (MDA) level as well as expression and activity of Mn SOD in cortex were determined. It was found that function of passive learning and memory and spatial recognition decreased, MDA level and Mn SOD expression increased during the period of chronic Al loading, but the Mn SOD activity rose from the 4th week and then decreased from the 8th week in cortex in Al overloading mice compared with the control. The results indicated that the inconsistency between Mn SOD expression and its activity might contribute to the development of recognition dysfunction induced by chronic Al overload.

Successful production of offspring after superovulation and in vitro culture of embryos from domestic ferrets (Mustela putorius furos).

In an effort to expand the use of ferrets as models for genetic disease, several experimental parameters that are required for successful genetic manipulation in this species were investigated. Optimum superovulation (19.3 +/- 0.6 oocytes and embryos per female) was achieved after injections of 100 iu equine chorionic gonadotrophin (eCG) and 150 iu human chorionic gonadotrophin (hCG). The ovulation rate achieved by the treatment was more than double that induced by mating. Mating with a male immediately after hCG treatment did not significantly alter the number of oocytes ovulated or the number of embryos present, indicating that mating is not required for superovulation in ferrets. Of embryos harvested at the one-cell stage, 64.5% and 47.1% developed into blastocysts when cultured in vitro in CZB or TCM-199 plus 10% fetal bovine serum (FBS) media, respectively. In contrast, only 17.1% of embryos cultured in vitro in NCSU-23 developed to the blastocyst stage. Both freshly retrieved and in vitro cultured embryos from cinnamon-coloured parents produced live young when transferred at the eight-cell stage into albino, pseudo-pregnant recipients. The percentage of kits delivered relative to embryos transferred was 61% for freshly retrieved embryos and 32% for embryos cultured in vitro. These results demonstrate successful embryo transfer in ferrets and provide a basis for further study of genetic modelling approaches in this species after embryo manipulation.