Super-assembled periodic mesoporous organosilica membranes with hierarchical channels for efficient glutathione sensing.

Bioinspired nanochannel-based sensors have elicited significant interest because of their excellent sensing performance, and robust mechanical and tunable chemical properties. However, the existing designs face limitations due to material constraints, which hamper broader application possibilities. Herein, a heteromembrane system composed of a periodic mesoporous organosilica (PMO) layer with three-dimensional (3D) network nanochannels is constructed for glutathione (GSH) detection. The unique hierarchical pore architecture provides a large surface area, abundant reaction sites and plentiful interconnected pathways for rapid ionic transport, contributing to efficient and sensitive detection. Moreover, the thioether groups in nanochannels can be selectively cleaved by GSH to generate hydrophilic thiol groups. Benefiting from the increased hydrophilic surface, the proposed sensor achieves efficient GSH detection with a detection limit of 1.2 µM by monitoring the transmembrane ionic current and shows good recovery ranges in fetal bovine serum sample detection. This work paves an avenue for designing and fabricating nanofluidic sensing systems for practical and biosensing applications.

Liquid harvesting and transport on multiscaled curvatures.

Various creatures, such as spider silk and cacti, have harnessed their surface structures to collect fog for survival. These surfaces typically stay dry and have a large contact hysteresis enabling them to move a condensed water droplet, resulting in an intermittent transport state and a relatively reduced speed. In contrast to these creatures, here we demonstrate that Nepenthes alata offers a remarkably integrated system on its peristome surface to harvest water continuously in a humid environment. Multicurvature structures are equipped on the peristome to collect and transport water continuously in three steps: nucleation of droplets on the ratchet teeth, self-pumping of water collection that steadily increases by the concavity, and transport of the acquired water to overflow the whole arch channel of the peristome. The water-wetted peristome surface can further enhance the water transport speed by ∼300 times. The biomimetic design expands the application fields in water and organic fogs gathering to the evaporation tower, laboratory, kitchen, and chemical industry.

Selenium-modified calcium phosphate cement can accelerate bone regeneration of osteoporotic bone defect.

OBJECTIVE: The purpose is to observe whether local administration with selenium (Se) can enhance the efficacy of calcium phosphate cement (CPC) in the treatment of osteoporotic bone defects. METHODS: Thirty ovariectomized (OVX) rats with two defects were generated and randomly allocated into the following graft study groups: (1) OVX group (n = 10), (2) CPC group (n = 10); and (3) Se-CPC group (n = 10). Then, these selenium-modified calcium phosphate cement (Se-CPC) scaffolds were implanted into the femoral epiphysis bone defect model of OVX rats for 12 weeks. Micro-CT, history, western blot and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis were used to observe the therapeutic effect and to explore the possible mechanism. RESULT: Micro-CT and histological analysis evaluation showed that the Se-CPC group presented the strongest effect on bone regeneration and bone mineralization when compared with the CPC group and the OVX group. Protein expressions showed that the oxidative stress protein expressions, such as SOD2 and GPX1 of the Se-CPC group, are significantly higher than those of the OVX group and the CPC group, while Se-CPC remarkably reduced the expression of CAT. RT-qPCR analysis showed that the Se-CPC group displayed more OPG than the OVX and CPC groups (p < 0.05), while Se-CPC exhibited less RANKL than the OVX and CPC groups (p < 0.05). CONCLUSION: Our current study demonstrated that Se-CPC is a scheme for rapid repair of femoral condylar defects, and these effects may be achieved by inhibiting local oxidative stress and through OPG/RANKL signaling pathway.

Local administration of aspirin with ß-tricalcium phosphate/poly-lactic-co-glycolic acid (ß-TCP/PLGA) could enhance osteoporotic bone regeneration.

Composite materials ß-tricalcium phosphate (ß-TCP) and poly-lactic-co-glycolic acid (PLGA) have achieved stable bone regeneration without cell transplantation in previous studies. Recent research shows that aspirin (ASP) has great potential in promoting bone regeneration. The objective of the present study was to incorporate PLGA into ß-TCP combined with a lower single-dose local administration of ASP to enhance its in vivo biodegradation and bone tissue growth. After the creation of a rodent critical-sized femoral metaphyseal bone defect, PLGA -modified ß-TCP (TP) was prepared by mixing sieved granules of ß-TCP and PLGA (50:50, v/v) for medical use, then TP with dripped 50 µg/0.1 ml and 100 µg/0.1 ml aspirin solution was implanted into the defect of OVX rats until death at 8 weeks. The defected area in distal femurs of rats was harvested for evaluation by histology, micro-CT, biomechanics and real time RT-PCR. The results of our study show that a single-dose local administration of ASP combined with the local usage of TP can increase the healing of defects in OVX rats. Single-dose local administration of aspirin can improve the transcription of genes involved in the regulation of bone formation and vascularization in the defect area, and inhibits osteoclast activity. Furthermore, treatments with a higher single-dose local administration of ASP and TP showed a stronger effect on accelerating the local bone formation than while using a lower dose of ASP. The results from our study demonstrate that the combination of a single-dose local administration of ASP and ß-TCP/PLGA had an additive effect on local bone formation in osteoporosis rats, and bone regeneration by PLGA/ß-TCP/ASP occured in a dose-dependent manner.

Single-dose local administration of parathyroid hormone (1-34, PTH) with ß-tricalcium phosphate/collagen (ß-TCP/COL) enhances bone defect healing in ovariectomized rats.

Parathyroid hormone (1-34, PTH) combined ß-tricalcium phosphate (ß-TCP) achieves stable bone regeneration without cell transplantation in previous studies. Recently, with the development of tissue engineering slow release technology, PTH used locally to promote bone defect healing become possible. This study by virtue of collagen with a combination of drugs and has a slow release properties, and investigated bone regeneration by ß-TCP/collagen (ß-TCP/COL) with the single local administration of PTH. After the creation of a rodent critical-sized femoral metaphyseal bone defect, ß-TCP/COL was prepared by mixing sieved granules of ß-TCP and atelocollagen for medical use, then ß-TCP/COL with dripped PTH solution (1.0 µg) was implanted into the defect of OVX rats until death at 4 and 8 weeks. The defected area in distal femurs of rats was harvested for evaluation by histology, micro-CT, and biomechanics. The results of our study show that single-dose local administration of PTH combined local usage of ß-TCP/COL can increase the healing of defects in OVX rats. Furthermore, treatments with single-dose local administration of PTH and ß-TCP/COL showed a stronger effect on accelerating the local bone formation than ß-TCP/COL used alone. The results from our study demonstrate that combination of single-dose local administration of PTH and ß-TCP/COL had an additive effect on local bone formation in osteoporosis rats.

The effects of combined human parathyroid hormone (1-34) and simvastatin treatment on the interface of hydroxyapatite-coated titanium rods implanted into osteopenic rats femurs.

The effect of human parathyroid hormone 1-34 (PTH) and simvastatin (SIM) alone could promote bone healing in osteoporotic implant fixation, but there are no reports about the combined use of PTH and SIM for promotion of bone healing around implant in osteoporotic settings. This study aims to investigate effects of PTH + SIM on implant stabilization in osteopenic rats. Fourteen weeks after chronically fed a low protein diet, osteopenic rats randomly received implants. Subsequently, the animals were randomly divided into four groups: Control, SIM, PTH and PTH + SIM. Then all rats from groups PTH, SIM and PTH + SIM received PTH (40 µg/kg, three times a week), SIM (25 mg/kg, daily), or both for 12 weeks. The results of our study indicated that all treatments promoted bone healing around implant compared to Control, but PTH + SIM treatment showed significantly stronger effects than PTH or SIM alone in histological, micro-CT, and biomechanical tests. The results indicated additive effects of PTH and SIM on implant fixation in osteoporotic rats.

Orthodontic force/torque modeling and experiment of Kitchon root-controlled auxiliary archwire.

The incidence of oral malocclusion is increasing and is seriously damaging the oral health of human beings. The Kitchon root-controlled auxiliary archwire is an individualized orthodontic arch. It is used clinically for the treatment of tooth-lingual tilt/root-lip tilt phenomenon of the central incisors. However, the bending parameters of the Kitchon root-controlled auxiliary archwire used in different patients are based on the clinical experience of the dentists. Therefore, this orthodontic treatment has a high risk and unpredictability. In this paper, the loading performance and orthodontic process of Kitchon root-controlled auxiliary archwire are analyzed. And the prediction model of support resistance and correction torque are established. The bending parameters of the Kitchon root-controlled auxiliary archwire, as well as the effect of the bending parameters on the support resistance and the correction torque, are all quantified. And the prediction models for the support resistance and the correction torque are calculated separately. The correlation coefficients of calculated data and experimental data are ξT1 > .97 and ξA1 > .96, respectively; the correlation coefficients of simulated data and experimental data are ξT2 > .96 and ξA2 > .96, respectively. The accuracy and reliability of the established prediction models are verified. It provides an effective theoretical guide for dentists to safely and efficiently perform root-controlled rotation orthodontic treatment on patients' central incisors.

In silico fatigue performance of molars restored with full crowns under alternating cyclic loadings.

OBJECTIVE: In this study, a preclinical approach was used to analyze and directly compare the fatigue performance (fatigue life and damage percentage) and maximum principal stresses (Max. Ps) of prepared models treated with different materials and geometric parameters. METHODS: Four groups of preparative parameters (crown width, crown length, degree of polymerization and material) were selected, each with five variables. An alternating cyclic occlusal load with an amplitude of 300 N was applied to the ball part along the longitudinal axis. The fatigue properties of the preparations and Max.Ps were analyzed. RESULTS: A shoulder width of 0.8 mm, a shoulder height offset of 0.2 mm, a degree of polymerization of 5°, and a crown material of ZC resulted in the smallest percentage of damage. In contrast, the effect of different modulus of elasticity (MOE) on Max.Ps was not significant (p = 0.609). CONCLUSION: The results suggest that the selection of larger modulus of elasticity MOE and larger Poisson's ratio material's, preparation of larger shoulder widths within safety, reasonable increase in crown length, and selection of larger degree of polymerization are favorable methods to protect the preparation.

Stress intensity factor of a cracked molar restored with different materials and designs: A 3D-FEA.

OBJECTIVE: This work used 3D finite element analysis (FEA) to analyze and directly compare the stress intensity factor (SIF) and stress distribution at the crack tip of identical cracked tooth models restored with different materials and crown parameters. METHODS: A 3D model of the cracked tooth was generated. Then, we applied 25 restorative models, including three parameters (shoulder height, width, and degree of polymerization), five restorative materials (GC, IPS, LU, ZC, VE), and two combinations of types of cement (RMGIC and GIC). An occlusal load of 800N was applied to the spherical part along the longitudinal axis. The stress distribution of the preparation and the SIF of the crack tip was analyzed. RESULTS: The crack tip SIF was minimal for a shoulder height offset of 0.8 mm (P = 0.032), a shoulder width of 0.6 mm (P = 0.045), a crown material of ZC (P < 2e-16), and a cement material of RMGIC (P < 0.05), respectively. In contrast, the effect of different polymerization degrees on SIF was insignificant (P = 0.95). CONCLUSION: Our results suggest that the selection of a larger modulus of elasticity (MOE) material for the crown, the preparation of a smaller shoulder width within a safe range, a reasonable increase in the crown length, and the selection of adhesive materials with high fracture toughness are favorable methods to prevent further crack extension.

Local administration with tauroursodeoxycholic acid could improve osseointegration of hydroxyapatite-coated titanium implants in ovariectomized rats.

Despite advances in the pathogenesis of Tauroursodeoxycholic acid (TUDCA) on bone, the understanding of the effects and mechanisms of bone osseointegration in TUDCA-associated Hydroxyapatite (HA)-coated titanium implants remains poor. Therefore, the present work was aimed to evaluate the effect of local administration with TUDCA on HA-coated titanium implants osseointegration in ovariectomized(OVX) rats and further investigation of the possible mechanism. Twelve weeks after bilateral ovariectomy, all animals were randomly divided into three groups: sham operation(Sham) group, OVX group and TUDCA group, and all the rats from Sham group and OVX group received HA implants and animals belonging to group TUDCA received TUDCA-HA implants until death at 12 weeks. The bilateral femurs of rats were harvested for evaluation. TUDCA increased new bone formation around the surface of titanium rods and push-out force other than group OVX. Histology, Micro-CT and biochemical analysis results showed systemic TUDCA showed positive effects than OVX group on bone formation in osteopenic rats, with beneficial effect on via activation OPG/RANKL pathway and BMP-2/Smad1 pathway and microarchitecture as well as by reducing protein expression of TNF-α and IFN-γ. The present study suggests that local use of TUDCA may bring benefits to the osseointegration of HA-coated titanium implants in patients with osteoporosis, and this effect may be related to the inhibition of inflammatory reaction and promotion of osteogenesis.

Aspirin modified strontium-doped ß-tricalcium phosphate can accelerate the healing of femoral metaphyseal defects in ovariectomized rats.

The purpose was to observe whether local administration Strontium (Sr) and Aspirin (Asp) can enhance the efficacy of ß-Tricalcium phosphate(ß-TCP) in the treatment of osteoporotic bone defect. The MC3T3-E1 cells were co-cultured with ß-TCP, Sr/ß-TCP, Asp-Sr/ß-TCP scaffold and induced to osteogenesis, and the cell viability, mineralization ability were observed by MTT, Alizarin Red staining(ARS) and Western blotting(WB). Then this scaffolds were implanted into the femoral epiphysis bone defect model of ovariectomized(OVX) rats for 8 weeks. X-ray, Micro-CT, histology and Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis were used to observe the therapeutic effect and explore the possible mechanism. MTT, ARS results show that the cell mineralization and viability of Asp-Sr/ß-TCP group is significantly higher than Control group, ß-TCP group and Sr/ß-TCP group. Protein expression show that the osteogenic protein expression such as ALP、OP、RUNX-2、OC and COL-1 of Asp-Sr/ß-TCP group is significantly higher than Control group, ß-TCP group and Sr/ß-TCP group. X-ray images, Micro-CT and Histological analysis evaluation show that, group Asp-Sr/ß-TCP presented the strongest effect on bone regeneration and bone mineralization, when compared with ß-TCP group and Sr/ß-TCP group. RT-qPCR analysis show that Asp-Sr/ß-TCP, ß-TCP group and Sr/ß-TCP group showed increased BMP2, Smad1, OPG than the OVX group(p < 0.05), while Asp-Sr/ß-TCP exhibited decreased TNF-α、IFN-γ and RANKL than the OVX group(p < 0.05). Our current study demonstrated that Asp-Sr/ ß-TCP is a scheme for rapid repair of femoral condylar defects, and these effects may be achieved by inhibiting local inflammation and through BMP-2/Smad1 and OPG/RANKL signaling pathway.

Quality consistency evaluation on four origins of Cicadae Periostracum by ultra-performance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry analysis.

Cicadae Periostracum, which is derived from the slough of Cicadidae insects, is a commonly used crude drug in traditional Chinese medicine (TCM). As specified in Chinese Pharmacopoeia, Cryptotympana atrata (CA) is the only official species of this crude drug. However, the slough of other three species, i.e., Auritibicen flammatus (AF), Cryptotympana mandrina (CM) and Platypleura kaempferi (PK), have been also used as the origins of Cicadae Periostracum in Chinese herbal market, although whether the quality of these four origins is consistent or not is still unknown. In present study, ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS/MS) was employed to qualitatively and quantitatively compare the chemical profiles of the four origins. Totally, 34 N-acetyldopamine polymers were identified from the four origins, including 4 N-acetyldopamine dimers, 11 N-acetyldopamine trimers, 10 N-acetyldopamine tetramers, and 9 N-acetyldopamine pentamers. AF, CM and PK had similar chemical profiles with that of CA. The contents and compositional ratio of the four types of polymers in CA, AF and CM were consistent with each other, but significantly lower or different in PK. All these results suggested that AF and CM might be considered as the potential resources of Cicadae Periostracum concerning their consistent holistic quality, whereas whether PK could be used as potential origin of Cicadae Periostracum or not need further evaluation for their different compositional ratios and contents of the four types of N-acetyldopamine polymers. This is the first study on chemical profiling and comparison of N-acetyldopamine polymers in four origins of Cicadae Periostracum, which is beneficial for potential resources utilization and quality standard improvement of Cicadae Periostracum.

[Analysis of hidden blood loss and its risk factors in the treatment of osteoporotic vertebral compression fractures with PVP].

OBJECTIVE: To investigate the influencing factors of hidden blood loss (HBL) during the treatment of percutaneous vertebroplasty (PVP). METHODS: The clinical data of 125 patients with osteoporotic vertebral compression fractures (OVCFs) treated with percutaneous vertebroplasty from March 2016 to December 2017 were retrospectively analyzed. All patients underwent X rays of the AP and lateral lumbar spine, double oblique, and dynamic positions. Lumbar spine CT, MRI, and dual energy X ray bone densitometer (DXA) were used to confirm the diagnosis. There were 55 males and 70 females, 10 cases of thoracic vertebrae, 89 cases of thoracolumbar vertebrae, 26 cases of lumbar vertebrae, 87 cases with single segment, 29 cases with double segment,and 9 cases with 3 segments. The vertebral compression height ratios of 67 patients were less than 1 / 3, and the ratios for 41 patients were from 1 / 3 to 2 / 3,for 17 patients were more than 2 / 3. Blood routine examination were performed before and 3 days after surgery to analyze hidden blood loss and to explore its risk factors. RESULTS: The average hidden blood loss was (317±156) ml in 125 patients. Multiple linear regression analysis revealed a history of diabetes(P=0.011),surgical segments(P=0.036),number of segments (P<0.001),vertebral height loss rate (P=0.002),vertebral height recovery rate (P<0.001) and bone cement leakage rate (P=0.003) were positively correlated with hidden blood loss. Moreover,it was found that the blood loss was higher in those with higher vertebral height loss rate than in those with lower vertebral height loss rate, and the blood loss was higher in those with good vertebral height recovery than those with poor vertebral height recovery. Additionally,the cement leakage was also an important factor in increasing hidden blood loss. However,there was no significant correlation between bone mineral density(P=0.814) or history of hypertension(P=0.055) and hidden blood loss. CONCLUSION: Patients with OVCFs have a large amount of hidden blood loss after PVP treatment, which needs attention. At the same time, the history of diabetes, surgical segments, number of segments, bone cement leakage rate, vertebral height loss rate and vertebral height recovery rate are the risk factors for hidden blood loss.

Nanoparticles for the Treatment of Oral Biofilms: Current State, Mechanisms, Influencing Factors, and Prospects.

Due to their excellent size, designability, and outstanding targeted antibacterial effects, nanoparticles have become a potential option for controlling oral biofilm-related infections. However, the formation of an oral biofilm is a dynamic process, and factors affecting the performance of antibiofilm treatments are complex. As such, when examining the existing literature on the antibiofilm effects of nanoparticles, attention should be paid to the specific mechanisms of action at different stages of oral biofilm formation, as well as relevant influencing factors, in order to achieve an objective and comprehensive evaluation. This review is intended to detail the antibacterial mechanisms of nanoparticles during the four stages of the formation of oral biofilms: 1) acquired film formation; 2) bacterial adhesion; 3) early biofilm development; and 4) biofilm maturation. In addition, factors influencing the antibiofilm properties of nanoparticles are summarized from the aspects of nanoparticles themselves, biofilm models, and host factors. The limitations of current research and possible trends for future research are also discussed. In summary, nanoparticles are a promising antioral biofilm strategy. It is hoped that this review can serve as a reference and inspire ideas for further research on the application of nanoparticles for effectively targeting and treating oral biofilms.

Analysis of the volatile compounds in Ligusticum chuanxiong Hort. using HS-SPME-GC-MS.

A headspace solid-phase microextraction (HS-SPME) method followed by gas chromatography-mass spectrometry (GC-MS) is described for the analysis of volatile compounds in the dry rhizome of Ligusticum chuanxiong Hort. Three types of SPME fibers including PDMS, PDMS-DVB and DVB-CAR-PDMS were investigated and the best extraction was achieved with the mixed fiber DVB-CAR-PDMS. Parameters for HS-SPME in terms of temperature and time, sample amount and particle size, and desorption time were also investigated. A polar capillary column was used for the chromatographic separation. As a result, 73 compounds were determined and identified by the HS-SPME-GC-MS method with at least 20 more compounds than those in the methods available. Comparison was made between HS-SPME-GC-MS and steam distillation (SD)-GC-MS methods. Using much less sample amount, shorter extraction time and simpler procedure, HS-SPME method can achieve similar results with those by SD. In conclusion, the present method is simple, rapid and effective and can be used for the analysis of volatile compounds in medicinal plants.

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.

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.

A comparative study of strontium-substituted hydroxyapatite coating on implant's osseointegration for 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. Strontium (Sr) promotes osteoblast proliferation and inhibits osteoclast proliferation and positively affects bone regeneration. The aim of this study was to confirm the effects of strontium-substituted hydroxyapatite (Sr-HA) coating via electrochemical deposition on implant's osseointegration 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 5 % Sr-HA; group 10 % Sr-HA; and group 20 % Sr-HA. Afterward, all rats from groups HA, 5 % Sr-HA, 10 % Sr-HA, and 20 % Sr-HA received implants with hydroxyapatite coating containing 0, 5, 10, and 20 % Sr. 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 20 % Sr-HA showed the strongest effects on new bone formation and biomechanical strength. Additionally, these are significant differences in bone formation and push-out force was observed between groups 5 % Sr-HA and 10 % Sr-HA. This finding suggests that Sr-HA coating can improve implant osseointegration, and the 20 % Sr coating exhibited the best properties for implant osseointegration among the tested coatings in osteoporosis rats.

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.

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

The objective of this study was to evaluate local bone formation following systemic administration of parathyroid hormone (1-34), a surgically implanted synthetic ß-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 ß-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 ß-tricalcium phosphate. Osteoporosis can limit the function of parathyroid hormone and/or ß-tricalcium phosphate. The results from our study demonstrate that combination of parathyroid hormone and ß-tricalcium phosphate brings better effect to bone tissue repair in non-osteoporosis and/or osteoporosis status.