Effect of bisphosphonate on bone microstructure, mechanical strength in osteoporotic rats by ovariectomy.

BACKGROUND: Bisphosphonate (BP) can treat osteoporosis and prevent osteoporotic fractures in clinical. However, the effect of BP on microstructure and mechanical properties of cortical and trabecular bone has been taken little attention, separately. METHODS: In this study, BP was used to intervene in ovariectomized female SD rats. The femoral micro-CT images were used to measure the structural parameters and reconstruct the 3D models in volume of interest. The structural parameters of cortical and trabecular bone were measured, and the mechanical properties were predicted using micro-finite element analysis. RESULTS: There was almost no significant difference in the morphological structure parameters and mechanical properties of cortical bone between normal, ovariectomized (sham-OVX) and BP intervention groups. However, BP could significantly improve bone volume fraction (BV/TV) and trabecular separation (Tb.SP) in inter-femoral condyles (IT) (sham-OVX vs. BP, p < 0.001), and had no significant effect on BV/TV in medial and lateral femoral condyles (MT, LT). Similarly, BPs could significantly affect the effective modulus in IT (sham-OVX vs. BP, p < 0.001), and had no significant difference in MT and LT. In addition, the structural parameters and effective modulus showed a good linear correlation. CONCLUSION: In a short time, the effects of BP intervention and osteoporosis on cortical bone were not obvious. The effects of BP on trabecular bone in non-main weight-bearing area (IT) were valuable, while for osteoporosis, the main weight-bearing area (MT, LT) may improve the structural quality and mechanical strength of trabecular bone through exercise compensation.

Examining the Impact of Acute Binge Alcohol Consumption on Trabecular Morphometry and Tensile Strength in Adolescent Sprague Dawley Rat Mandibles / Análisis del Impacto del Consumo Excesivo de Alcohol en la Morfometría Trabecular y la Resistencia a la Tracción en Mandíbulas de Ratas Adolescentes Sprague Dawley

SUMMARY: Underage drinking has become a major public concern having a negative impact on the growth and development of the skeleton. Peak bone mass is attained during adolescence hence the aim of the study was to investigate the effect of acute binge alcohol consumption on trabecular morphometry and tensile strength of the adolescent mandible in the Sprague Dawley (SD) rat. The study comprised of 24 SD rats, aged 7 weeks, placed into either the alcohol-exposed [n=12 (6 males and 6 female)] or pair-fed control group [n=12 (6 male and 6 female)]. The treatment of the groups was as follows; the alcohol exposed group and the pair-fed control were administered a single daily dose of 3 g/kg of 20 % alcohol 3 days a week (alternate days) for 7 days and a caloric equivalent dose of maltose dextrin via oral gavage, respectively. The animals were terminated on day 7 via pentobarbital injection. The mandibles were harvested and scanned using a Nikon XTH 255L 3D-microCT scanner (Nikon Metrology, Leuven, Belgium), and biomechanical tests were done using a Shimadzu universal tensile strength testing machine (China). Following scanning and reconstruction, the trabecular morphometry was assessed using Volume Graphics Studio® software. A 3-point bending test was used to evaluate the tensile strength of the bone. Findings from our study showed changes in some trabecular parameters in the female alcohol-exposed group, while the male groups remained unaffected. No changes in tensile strength were seen when comparing male pair-fed control and alcohol-exposed groups and when comparing female pair-fed control and alcohol-exposed groups. Trabecular and tensile strength differences were observed between the sexes when comparing male pair-fed control and alcohol-exposed groups to female pair-fed control and alcohol-exposed groups. These findings do suggest that acute binge alcohol consumption has detrimental effects on the bone micro-architecture in female alcohol-exposed rats and that differences are seen between the sexes.

El consumo de alcohol entre menores de edad se ha convertido en una importante preocupación pública que tiene un impacto negativo en el crecimiento y desarrollo del esqueleto. La masa ósea máxima se alcanza durante la adolescencia, por lo que el objetivo del estudio fue investigar el efecto del consumo excesivo de alcohol en forma aguda sobre la morfometría trabecular y la resistencia a la tracción de la mandíbula en ratas adolescente Sprague Dawley (SD). El estudio estuvo compuesto por 24 ratas, de 7 semanas de edad, colocadas en el grupo control expuesto al alcohol [n=12 (6 machos y 6 hembras)] y alimentado en parejas [n=12 (6 machos y 6 hembras)]. El tratamiento de los grupos fue el siguiente; al grupo expuesto al alcohol y al control alimentado en parejas se les administró una dosis única diaria de 3 g/kg de alcohol al 20 % 3 días a la semana (días alternos) durante 7 días y una dosis equivalente calórica de maltosa dextrina mediante sonda oral, respectivamente. Los animales fueron sacrificados el día 7 mediante inyección de pentobarbital. Las mandíbulas se recolectaron y se escanearon utilizando un escáner 3D-microCT Nikon XTH 255L (Nikon Metrology, Lovaina, Bélgica), y las pruebas biomecánicas se realizaron utilizando una máquina de prueba de resistencia a la tracción universal Shimadzu (China). Después del escaneo y la reconstrucción, la morfometría trabecular se evaluó utilizando el software Volume Graphics Studio®. Se utilizó una prueba de flexión de 3 puntos para evaluar la resistencia a la tracción del hueso. Los hallazgos de nuestro estudio mostraron cambios en algunos parámetros trabeculares en el grupo de hembras expuestas al alcohol, mientras que los grupos de machos no se vieron afectados. No se observaron cambios en la resistencia a la tracción al comparar los grupos control de machos alimentados en parejas y los grupos expuestos al alcohol y al comparar los grupos control de las hembras alimentadas en parejas y los grupos expuestos al alcohol. Se observaron diferencias trabeculares y de resistencia a la tracción entre los sexos al comparar los grupos control de los machos alimentados en parejas y expuestos al alcohol con los grupos de control de hembras alimentadas en parejas y expuestas al alcohol. Estos hallazgos sugieren que el consumo excesivo de alcohol tiene efectos perjudiciales sobre la microarquitectura ósea en ratas hembras expuestas al alcohol y que se observan diferencias entre los sexos.

Effects of daily teriparatide, weekly high-dose teriparatide, or bisphosphonate on cortical and trabecular bone of vertebra and proximal femur in postmenopausal women with fragility fracture: Sub-analysis by quantitative computed tomography from the TERABIT study.

PURPOSE: The effects of daily teriparatide (D-PTH, 20 µg/day), weekly high-dose teriparatide (W-PTH, 56.5 µg/week), or bisphosphonate (BP) on the vertebra and proximal femur were investigated using quantitative computed tomography (QCT). METHODS: A total of 131 postmenopausal women with a history of fragility fractures were randomized to receive D-PTH, W-PTH, or bisphosphonate (oral alendronate or risedronate). QCT were evaluated at baseline and after 18 months of treatment. RESULTS: A total of 86 participants were evaluated by QCT (Spine: D-PTH: 25, W-PTH: 21, BP: 29. Hip: PTH: 22, W-PTH: 21, BP: 32. Dropout rate: 30.5 %). QCT of the vertebra showed that D-PTH, W-PTH, and BP increased total vBMD (+34.8 %, +18.2 %, +11.1 %), trabecular vBMD (+50.8 %, +20.8 %, +12.2 %), and marginal vBMD (+20.0 %, +14.0 %, +11.5 %). The increase in trabecular vBMD was greater in the D-PTH group than in the W-PTH and BP groups. QCT of the proximal femur showed that D-PTH, W-PTH, and BP increased total vBMD (+2.8 %, +3.6 %, +3.2 %) and trabecular vBMD (+7.7 %, +5.1 %, +3.4 %), while only W-PTH and BP significantly increased cortical vBMD (-0.1 %, +1.5 %, +1.6 %). Although there was no significant increase in cortical vBMD in the D-PTH group, cortical bone volume (BV) increased in all three treatment groups (+2.1 %, +3.6 %, +3.1 %). CONCLUSIONS: D-PTH had a strong effect on trabecular bone of vertebra. Although D-PTH did not increase cortical BMD of proximal femur, it increased cortical BV. W-PTH had a moderate effect on trabecular bone of vertebra, while it increased both cortical BMD and BV of proximal femur. Although BP had a limited effect on trabecular bone of vertebra compared to teriparatide, it increased both cortical BMD and BV of proximal femur.

Dissolving magnesium hydroxide implants enhance mainly cancellous bone formation whereas degrading RS66 implants lead to prominent periosteal bone formation in rabbits.

Bone fractures often require internal fixation using plates or screws. Normally, these devices are made of permanent metals like titanium providing necessary strength and biocompatibility. However, they can also cause long-term complications and may require removal. An interesting alternative are biocompatible degradable devices, which provide sufficient initial strength and then degrade gradually. Among other materials, biodegradable magnesium alloys have been developed for craniofacial and orthopaedic applications. Previously, we tested implants made of magnesium hydroxide and RS66, a strong and ductile ZK60-based alloy, with respect to biocompatibility and degradation behaviour. Here, we compare the effects of dissolving magnesium hydroxide and RS66 cylinders on bone regeneration and bone growth in rabbit condyles using microtomographical and histological analysis. Both magnesium hydroxide and RS66 induced a considerable osteoblastic activity leading to distinct but different spatio-temporal patterns of cancellous and periosteal bone growth. Dissolving RS66 implants induced a prominent periosteal bone formation on the medial surface of the original condyle whereas dissolving magnesium hydroxide implants enhance mainly cancellous bone formation. Especially periosteal bone formation was completed after 6 and 8 weeks, respectively. The observed bone promoting functions are in line with previous reports of magnesium stimulating cancellous and periosteal bone growth and possible underlying signalling mechanisms are discussed. STATEMENT OF SIGNIFICANCE: Biodegradable magnesium based implants are promising candidates for use in orthopedic and traumatic surgery. Although these implants are in the scientific focus for a long time, comparatively little is known about the interactions between degrading magnesium and the biological environment. In this work, we investigated the effects of two degrading cylindrical magnesium implants (MgOH2 and RS66) both on bone regeneration and on bone growth. Both MgOH2 and RS66 induce remarkable osteoblastic activities, however with different spatio-temporal patterns regarding cancellous and periosteal bone growth. We hypothesize that degradation products do not diffuse directionless away, but are transported by the restored blood flow in specific spatial patterns which is also dependent on the used surgical technique.

Direct-Acting Oral Anticoagulant/Vitamin K Antagonists: Do They Affect the Trabecular and Cortical Structure of the Mandible?

BACKGROUND: This study aimed to evaluate the mandibular bone structure of patients using oral anticoagulants (OACs) vitamin K antagonist drugs (warfarin) and other OACs including direct oral anticoagulants [(DOACs) apixaban, rivaroxaban, dabigatran, edoxaban]. Analyses were based upon the fractal dimension (FD), the panoramic mandibular index (PMI) and the Klemetti index (KI), which is also known as the mandibular cortical index (MCI). METHODOLOGY: Ninety participants were divided into three groups: group 1: 30 systemically healthy individuals who had not used any anticoagulants before, group 2: 30 individuals using warfarin, and group 3: 30 individuals using DOACs. FD was used to analyze trabecular bone architecture in the condyle, angle, and two sites in the alveolar bone. PMI was used to evaluate the quantity of cortical bone and KI was used to evaluate the cortical bone quality. RESULTS: There was no difference between the groups regarding FD analysis and KI; however, a difference was found between groups 1, 2, and 3 in the PMI (P≤ 0.001). The PMI in group 1 was higher than in groups 2 and 3. CONCLUSION: Mandibular radiomorphometric indices can be used on panoramic radiographs to evaluate the quantity of mandibular cortical bone in patients using oral anticoagulants.

The Effects of Acute Binge Alcohol Consumption on the Trabecular Morphometry and Tensile Strength of Adolescent Sprague Dawley Rat Femora

SUMMARY: Excessive alcohol consumption adversely affects bone metabolism, thus resulting in reduced bone length, density, and strength. Moreover, these deficits in bone density and strength are likely to increase the risk of fragility fractures and the early onset of osteoporosis. While excessive alcohol consumption is an established risk factor for osteoporotic fractures, there remains a dearth of information in literature about bone effects of binge alcohol consumption in adolescents. Therefore, our study aimed to examine the effects of acute binge alcohol consumption on the adolescent bone micro-architecture and tensile strength. Twelve male Sprague Dawley rats aged 7 weeks were randomly placed in 2 groups: alcohol (n =6), receiving alcohol (3g/kg) and pair-fed control (n = 6), receiving an isocaloric equivalent of maltose dextrin via oral gavage for 3 days in one week (on alternative days). The femora were dissected and scanned using a Micro-Focus X-ray Computed Tomography (3D-µCT). Following reconstruction, trabecular morphometry was assessed in both the proximal and distal epiphysis, using a Volume Graphics Studio® software. A three-point bending test was employed to examine the effect of alcohol on the tensile strength of the bone. Results showed trabeculae parameters to be affected in the distal epiphysis of the femur, while in the proximal epiphysis it remained unaffected. Tensile strength parameters were also not affected by the consumption of alcohol. These findings may suggest that acute binge alcohol consumption has detrimental effects on the bone micro-architecture specific to the distal epiphysis.

El consumo excesivo de alcohol afecta negativamente al metabolismo óseo, lo que resulta en una reducción de la longitud, densidad y resistencia de los huesos. Además, es probable que estos déficits en la densidad y la fuerza ósea aumenten el riesgo de fracturas por fragilidad y la aparición temprana de osteoporosis. Si bien el consumo excesivo de alcohol es un factor de riesgo establecido para las fracturas osteoporóticas, existe escasa información en la literatura sobre los efectos óseos del consumo excesivo de alcohol en adolescentes. Por lo tanto, nuestro estudio tuvo como objetivo examinar los efectos del consumo excesivo de alcohol en la microarquitectura ósea y la resistencia a la tracción e n ratas adolescentes. Doce ratas macho Sprague Dawley de 7 semanas de edad se colocaron aleatoriamente en 2 grupos: alcohol (n = 6), que recibieron alcohol (3 g/kg) y control (n = 6), que recibieron un equivalente isocalórico de maltosa dextrina mediante sonda oral, durante 3 días en una semana (en días alternos). Los fémures se diseccionaron y escanearon mediante una tomografía computarizada de rayos X con microenfoque (3D-mCT). Después de la reconstrucción, se evaluó la morfometría trabecular tanto en la epífisis proximal como en la distal, utilizando un software Volume Graphics Studio®. Se empleó una prueba de flexión de tres puntos para examinar el efecto del alcohol sobre la resistencia a la tracción del hueso. Los resultados mostraron que los parámetros de las trabéculas se vieron afectados en la epífisis distal del fémur, mientras que en la epífisis proximal no se observaron afectados. Los parámetros de resistencia a la tracción tampoco se vieron afectados por el consumo de alcohol. Estos hallazgos pueden sugerir que el consumo excesivo de alcohol tiene efectos perjudiciales sobre la microarquitectura ósea específica de la epífisis distal del hueso.

Bone quality affects stability of orthodontic miniscrews.

The objective of this study was to evaluate the effect of bone-miniscrew contact percentage (BMC%) and bone quality and quantity on orthodontic miniscrew stability and the maximum insertion torque value (ITV). Orthodontic miniscrews of five different dimensions and several bovine iliac bone specimens were used in the evaluation. Miniscrews of each dimension group were inserted into 20 positions in bovine iliac bone specimens. The experiment was divided into three parts: (1) Bone quality and quantity were evaluated using cone-beam computed tomography (CBCT) and microcomputed tomography. (2) The 3D BMC% was calculated. (3) The ITVs during miniscrew insertion were recorded to evaluate the stability of the orthodontic miniscrews. The results indicated that longer and thicker miniscrews enabled higher ITVs. CBCT was used to accurately measure cortical bone thickness (r = 0.939, P < 0.05) and to predict the bone volume fraction of cancellous bone (r = 0.752, P < 0.05). BMC% was significantly influenced by miniscrew length. The contribution of cortical bone thickness to the ITV is greater than that of cancellous bone structure, and the contribution of cortical bone thickness to BMC% is greater than that of cancellous bone structure. Finally, the higher is BMC%, the greater is the ITV. This study concludes that use of CBCT may predict the mechanical stability of orthodontic miniscrews.

Effect of Acetazolamide and Zoledronate on Simulated High Altitude-Induced Bone Loss.

Exposure to hypobaric hypoxia at high altitude puts mountaineers at risk of acute mountain sickness. The carbonic anhydrase inhibitor acetazolamide is used to accelerate acclimatization, when it is not feasible to make a controlled and slow ascend. Studies in rodents have suggested that exposure to hypobaric hypoxia deteriorates bone integrity and reduces bone strength. The study investigated the effect of treatment with acetazolamide and the bisphosphonate, zoledronate, on the skeletal effects of exposure to hypobaric hypoxia. Eighty 16-week-old female RjOrl : SWISS mice were divided into five groups: 1. Baseline; 2. Normobaric; 3. Hypobaric hypoxia; 4. Hypobaric hypoxia + acetazolamide, and 5. Hypobaric hypoxia + zoledronate. Acetazolamide was administered in the drinking water (62 mg/kg/day) for four weeks, and zoledronate (100 µg/kg) was administered as a single subcutaneous injection at study start. Exposure to hypobaric hypoxia significantly increased lung wet weight and decreased femoral cortical thickness. Trabecular bone was spared from the detrimental effects of hypobaric hypoxia, although a trend towards reduced bone volume fraction was found at the L4 vertebral body. Treatment with acetazolamide did not have any negative skeletal effects, but could not mitigate the altitude-induced bone loss. Zoledronate was able to prevent the altitude-induced reduction in cortical thickness. In conclusion, simulated high altitude affected primarily cortical bone, whereas trabecular bone was spared. Only treatment with zoledronate prevented the altitude-induced cortical bone loss. The study provides preclinical support for future studies of zoledronate as a potential pharmacological countermeasure for altitude-related bone loss.

Diosmin, a citrus fruit-derived phlebotonic bioflavonoid protects rats from chronic kidney disease-induced loss of bone mass and strength without deteriorating the renal function.

Kidney Disease Improving Global Outcomes (KDIGO) 2017 Clinical Practice Guideline has recommended treatment decisions for patients with chronic kidney disease (CKD) with osteoporosis and/or high risk of fracture. Bisphosphonates, the first-line anti-osteoporosis drugs have the concern of worsening kidney functions. Moreover, despite impaired bone formation in CKD patients, teriparatide, the formation-stimulating drug is not recommended. Thus, there is an urgent need for safe and effective treatment of osteoporosis in CKD patients. Here, in CKD rats, we tested the osteoprotective effect of diosmin, a citrus-derived bioflavonoid used as a phlebotonic in chronic venous insufficiency and has a renoprotective effect. CKD was developed by 5/6th nephrectomy and diosmin at the human equivalent dose (100 mg kg-1) did not advance renal failure but reduced blood pressure to the level of sham control. Fibroblast growth factor-23 and parathyroid hormone were increased in CKD and diosmin suppressed both. CKD reduced bone mass and deteriorated the microarchitecture of trabecular bones, and diosmin maintained both to control levels. Bone formation and strength were impaired in the CKD and diosmin maintained these levels to control levels. Nanoindentation of bone showed that diosmin significantly increased tissue hardness over the control. Diosmetin, the metabolic surrogate of diosmin had comparable pharmacokinetic profiles between the control and CKD groups. Furthermore, diosmetin (50 mg kg-1) protected against CKD-induced bone loss. These data suggest that diosmin and its metabolic surrogate, diosmetin protect against CKD-induced osteopenia. Since diosmin has no renal adverse effect and protected bone mass and strength in CKD rats, we propose assessing its anti-osteoporosis effect in CKD patients.

Ethanolic extract of Pyrrosia lingua (Thunb.) Farw. ameliorates OVX-induced bone loss and RANKL-induced osteoclastogenesis.

Pyrrosia lingua (Thunb.) Farw is a common plant that has been widely used as a traditional herbal medicine in China and Korea to treat patients suffering from pain, vaginal bleeding and urolithiasis. However, the pharmacological effects of P. lingua on bone remain unknown. We investigated the anti-osteoporotic effects of an ethanolic extract of P. lingua (EEPL). We found that EEPL suppressed osteoclast differentiation by directly acting on osteoclast precursor cells. EEPL suppressed the expression of receptor activator of nuclear factor-κB ligand (RANKL)-induced nuclear factor of activated T cells 1, a major transcription factor for osteoclastogenesis, by inhibiting RANKL-induced expression of aryl hydrocarbon receptor/c-Fos, and activation of nuclear factor-κB and mitogen-activated protein kinases. Moreover, administration of EEPL inhibited trabecular bone loss and weight gain in ovariectomized mice. Furthermore, we identified phytochemicals in EEPL that are known to exert anti-osteoclastogenic or anti-osteoporotic effects using ultra-high-performance liquid chromatography-tandem mass-spectrometry analysis. Overall, the results of this study suggest that EEPL is effective therapeutic candidate that can be used to prevent or treat postmenopausal osteoporosis.

The Long-Term Effects of Growth Hormone Replacement on Bone Mineral Density and Trabecular Bone Score: Results of the 10-Year Prospective Follow-up.

There are only few studies concerning about long-term effect of growth hormone (GH) replacement therapy on bone mineral density and bone microstructure. To assess effect of GH replacement therapy on bone mineral density (BMD) and trabecular bone score (TBS) in adult GH deficient (AGHD) subjects over period of 10 years. From 2005 to 2018, a prospective study of AGHD patients was conducted in national referral center for treatment of GHD. All patients received subcutaneous recombinant human GH in an IGF 1-normalizing regimen once a day. Lumbar spine (L-spine) and total hip (TH) BMD using Hologic densitometers were measured at baseline and every two years during treatment with rhGH. TBS was derived from L1-L4 DXA using iNsight® software (Medimaps, France) at each time point. Periods of measurement were baseline, year 2; 4; 6; 8 and 10. In total, 63 patients (38 males, 25 females, mean age 25.1±16 years) were included in the study. After 10 years of GH treatment, IGF-1 significantly increased (~35 %), with greatest increase at year 2. During 10-year follow-up, L-spine BMD increased approximately of 7 % (NS). TH BMD increase of 11 % during follow-up (p=0.0003). The greatest increment of BMD was achieved at year 6 on both sites, L-spine (+6 %) and TH BMD (+13 %) (p<0.05). There was no significant change of TBS during whole follow-up. In this study, sustaining positive effect of GH replacement therapy on bone density in subjects with adult GH deficiency over 10 years of follow-up was observed. The study did not show effect on TBS, as indirect measure of trabecular bone microarchitecture.

The Influence of Prenatal Fumonisin Exposure on Bone Properties, as well as OPG and RANKL Expression and Immunolocalization, in Newborn Offspring Is Sex and Dose Dependent.

The current study examined the effects of exposure of pregnant dams to fumonisins (FBs; FB1 and FB2), from the seventh day of pregnancy to parturition, on offspring bone metabolism and properties. The rats were randomly divided into three groups intoxicated with FBs at either 0, 60, or 90 mg/kg b.w. Body weight and bone length were affected by fumonisin exposure, irrespective of sex or dose, while the negative and harmful effects of maternal FBs' exposure on bone mechanical resistance were sex and dose dependent. The immunolocalization of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-Β ligand (RANKL), in bone and articular cartilage, indicated that the observed bone effects resulted from the FB-induced alterations in bone metabolism, which were confirmed by the changes observed in the Western blot expression of OPG and RANKL. It was concluded that the negative effects of prenatal FB exposure on the general growth and morphometry of the offspring bones, as a result of the altered expression of proteins responsible for bone metabolism, were dose and sex dependent.

Trabecular Bone Parameters, TIMP-2, MMP-8, MMP-13, VEGF Expression and Immunolocalization in Bone and Cartilage in Newborn Offspring Prenatally Exposed to Fumonisins.

Fumonisins are protein serine/threonine phosphatase inhibitors and potent inhibitors of sphingosine N-acyltransferase (ceramide synthase) disrupting de novo sphingolipid biosynthesis. The experiment was conducted to evaluate the effects of fumonisins (FB) exposure from the 7th day of pregnancy to parturition on offspring bone development. The rats were randomly allocated to either a control group (n = 6), not treated with FBs, or to one of the two groups intoxicated with FBs (either at 60 mg FB/kg b.w. or at 90 mg FB/kg b.w. Numerous negative, offspring sex-dependent effects of maternal FB exposure were observed with regards to the histomorphometry of trabecular bone. These effects were due to FB-inducted alterations in bone metabolism, as indicated by changes in the expression of selected proteins involved in bone development: tissue inhibitor of metalloproteinases 2 (TIMP-2), matrix metalloproteinase 8 (MMP-8), matrix metalloproteinase 13 (MMP-13), and vascular endothelial growth factor (VEGF). The immunolocalization of MMPs and TIMP-2 was performed in trabecular and compact bone, as well as articular and growth plate cartilages. Based on the results, it can be concluded that the exposure of pregnant dams to FB negatively affected the expression of certain proteins responsible for bone matrix degradation in newborns prenatally exposed to FB in a dose- and sex-dependent manner.

Additive Manufacturing of Caffeic Acid-Inspired Mineral Trioxide Aggregate/Poly-ε-Caprolactone Scaffold for Regulating Vascular Induction and Osteogenic Regeneration of Dental Pulp Stem Cells.

Mineral trioxide aggregate (MTA) is a common biomaterial used in endodontics regeneration due to its antibacterial properties, good biocompatibility and high bioactivity. Surface modification technology allows us to endow biomaterials with the necessary biological targets for activation of specific downstream functions such as promoting angiogenesis and osteogenesis. In this study, we used caffeic acid (CA)-coated MTA/polycaprolactone (PCL) composites and fabricated 3D scaffolds to evaluate the influence on the physicochemical and biological aspects of CA-coated MTA scaffolds. As seen from the results, modification of CA does not change the original structural characteristics of MTA, thus allowing us to retain the properties of MTA. CA-coated MTA scaffolds were shown to have 25% to 55% higher results than bare scaffold. In addition, CA-coated MTA scaffolds were able to significantly adsorb more vascular endothelial growth factors (p < 0.05) secreted from human dental pulp stem cells (hDPSCs). More importantly, CA-coated MTA scaffolds not only promoted the adhesion and proliferation behaviors of hDPSCs, but also enhanced angiogenesis and osteogenesis. Finally, CA-coated MTA scaffolds led to enhanced subsequent in vivo bone regeneration of the femur of rabbits, which was confirmed using micro-computed tomography and histological staining. Taken together, CA can be used as a potently functional bioactive coating for various scaffolds in bone tissue engineering and other biomedical applications in the future.

Tributyltin protects against ovariectomy-induced trabecular bone loss in C57BL/6J mice with an attenuated effect in high fat fed mice.

Risk factors for poor bone quality include estrogen loss at menopause, a high fat diet and exposures to drugs/chemicals that activate peroxisome proliferator activated receptor gamma (PPARγ). We previously reported that the PPARγ and retinoid X receptor dual ligand, tributyltin (TBT), repressed periosteal bone formation but enhanced trabecular bone formation in vivo. Here, we examined the interaction of diet, ovariectomy (OVX) and TBT exposure on bone structure. C57BL/6J mice underwent either sham surgery or OVX at 10 weeks of age. At 12 weeks of age, they were placed on a low (10% kcal) or high (45% kcal) fat, sucrose-matched diet and treated with vehicle or TBT (1 or 5 mg/kg) for 14 weeks. OVX increased body weight gain in mice on either diet. TBT enhanced body weight gain in intact mice fed a high fat diet, but decreased weight gain in OVX mice. Elemental tin concentrations increased dose-dependently in bone. TBT had marginal effects on cortical and trabecular bone in intact mice fed either diet. OVX caused a reduction in cortical and trabecular bone, regardless of diet. In high fat fed OVX mice, TBT further reduced cortical thickness, bone area and total area. Interestingly, TBT protected against OVX-induced trabecular bone loss in low fat fed mice. The protective effect of TBT was nullified by the high fat. These results show that TBT protects against trabecular bone loss, even in the presence of a strongly resorptive environment, at an even lower level of exposure than we showed repressed homeostatic resorption.

Intrauterine alcohol exposure disturbs trabecular morphology in the Sprague Dawley rat humerus epiphysis up to 3- weeks postnatally / La exposición al alcohol intrauterino altera la morfología trabecular en la epífisis del húmero de la rata Sprague Dawley hasta 3 semanas después del nacimiento

SUMMARY: Gestational alcohol exposure inhibits neurological as well as bone growth and development both in fetal and postnatal life. Stunted stature, osteoporosis and fractures in adult life are some of the adverse effects. While the impact of intrauterine alcohol on the brain has been extensively investigated, studies on the effects on bone are relatively few. Therefore, our study aimed to examine the impact of prenatal alcohol exposure on bone microarchitecture in 3-week-old rats using Micro-focus X-Ray Computed Tomography (Micro CT). Time mated pregnant Sprague Dawley dams (13) were randomly placed into 3 groups: ethanol (n=5), saline control (n=5) and untreated control (n=3). The former 2 groups received treatment with 0.015ml/g of 25.2 % ethanol and 0.9 % saline, respectively, for the first 19 days of gestation. The untreated group received no treatment. The pups remained with their dams until termination at 21 days of age. From each dam, 2 pups were collected resulting in: ethanol (n=10), saline controls (n= 10) and untreated controls (n = 6). The humeri of the pups were dissected and scanned using a 3D-μCT scanner (Nikon XTH 225L) at 15μm resolution. Trabecular and cortical parameters were analysed using Volume Graphics Studio® software following reconstruction. Results showed a decrease in trabecular size, spaces, thickness, and volume. There was a decrease in cortical bone area in the ethanol group compared to the controls. These findings may suggest that osteoporosis and fractures seen as gestational alcohol effects may be due to compromised trabecular structure.

RESUMEN: La exposición al alcohol durante la gestación inhibe el crecimiento y desarrollo neurológico y óseo tanto en la vida fetal como posnatal. Algunos de los efectos adversos incluyen la estatura atrofiada, osteoporosis y fracturas en la vida adulta. Si bien se ha estudiado el impacto del alcohol intrauterino en el cerebro, los estudios sobre los efectos en los huesos son escasos. Por lo tanto, nuestro estudio tuvo como objetivo examinar el impacto de la exposición prenatal al alcohol en la microarquitectura ósea en ratas de 3 semanas de edad utilizando Tomografía Computarizada de Rayos X Micro-focus (Micro CT). Las hembras de Sprague Dawley preñadas con apareamiento temporal (13) se colocaron aleatoriamente en 3 grupos: etanol (n = 5), control de solución salina (n = 5) y control sin tratar (n = 3). Los primeros 2 grupos recibieron tratamiento con 0,015 ml /g de etanol al 25,2 % y solución salina al 0,9 %, respectivamente, durante los primeros 19 días de gestación. El grupo no tratado no recibió tratamiento. Las crías permanecieron con sus madres hasta la terminación a los 21 días de edad. De cada madre, se recolectaron 2 crías que dieron como resultado: etanol (n = 10), controles salinos (n = 10) y controles no tratados (n = 6). Se diseccionaron y escanearon los húmero de las crías usando un escáner 3D-μCT (Nikon XTH 225L) a una resolución de 15 μm. Los parámetros trabeculares y corticales se analizaron utilizando el software Volume Graphics Studio® después de la reconstrucción. Los resultados mostraron una disminución en el tamaño trabecular, los espacios, el grosor y el volumen. Hubo una disminución en el área del hueso cortical en el grupo de etanol en comparación con los controles. Estos hallazgos pueden sugerir que la osteoporosis y las fracturas por causa de los efectos del alcohol gestacional se pueden deber a una estructura trabecular comprometida.

Early Bone Healing on Hydroxyapatite-Coated and Chemically-Modified Hydrophilic Implant Surfaces in an Ovine Model.

Implant topography affects early peri-implant bone healing by changing the osteoconduction rate in the surrounding biological environment. Implant surfaces have been designed to promote faster and stronger bone formation for rapid and stable prosthesis loading. Early peri-implant bone healing has been observed with a sandblasted, acid-etched implant that was chemically modified to be hydrophilic (cmSLA). The present study investigates whether early peri-implant bone healing extends to a rough surface implant with a high crystalline hydroxyapatite surface (TSV MP-1 HA). Three implants were randomly placed in porous trabecular bone within both medial femoral condyles of 10 sheep. Early peri-implant bone stability was measured at 3- and 6-weeks healing time following implant insertion. Results indicated a similar implant stability quotient between the implants at insertion and over time. The significant increase over time of reverse torque values with respect to insertion torque (p < 0.001) did not differ between the implants. However, the bone-to-implant contact of TSV MP-1 HA was significantly higher than that of cmSLA implants at 6 weeks (p < 0.01). These data validate previous findings of a hydrophilic implant surface and extend the observation of early osseointegration to a rough surface implant in porous trabecular bone.

Impact of bone-active drugs and underlying disease on bone health after lung transplantation: A longitudinal study.

INTRODUCTION: the effect of bone-active drugs on the risk of fragility fractures (Fx), bone mineral density (BMD) and trabecular bone score (TBS) changes in patients receiving lung transplantation (LTx) is largely unknown. This study assessed the bone-active drugs effect in patients undergoing LTx both with (CF) and without (nCF) cystic-fibrosis. METHODS: We evaluated incident Fx, both clinical and morphometric vertebral Fx by spinal X-ray, BMD and trabecular bone score (TBS) in 117 patients (CF=50, nCF n = 67) before and 24-months after LTx. A bone-active therapy was proposed to all LTx candidates. RESULTS: 83.8% of patients started a bone-active drug. Lumbar-spine (LS) T-score improved significantly only in treated patients (-1.4 ± 1.0 vs -2.0±1.0, p = 0.0001), whereas femur BMD and TBS remained stable in treated and not treated subjects. The rate of incident Fx was 15.3%, with no difference between treated and not treated patients. After LTx, LS T-score improved significantly only in nCF group (-1.3 ± 1.0 vs -1.8 ± 1.1, p = 0.0001), while femur remained stable in both nCF and CF groups. Patients with CF showed a significant Z-TBS increase (-3.6 ± 1.7 vs -3.0 ± 1.7, p = 0.019) and a lower Fx incidence as compared with nCF patients (4.1% vs 24.2%, p  =0.003). Incident Fx were associated with nCF diagnosis (OR 7.300, CI95% 1.385-38.461, p = 0.019) regardless of prevalent Fx, previous glucocorticoid therapy and bone-active therapy introduced at least 6 months before LTx. CONCLUSIONS: A prompt medical intervention helps in preventing BMD loss after LTx. As compared with nCF patients, CF patients show a TBS increase and a lower Fx risk after LTx.

Clinical Utility of Trabecular Bone Score (TBS) in Fracture Risk Assessment of Patients with Rheumatic Diseases Treated with Glucocorticoids.

Chronic glucocorticoid therapy is associated with osteoporosis and can cause fractures in up to 50% of patients. Increased risk of fractures in patients with glucocorticoid-induced osteoporosis does not result only from the decreased bone mineral density (BMD) but also bone microarchitecture deterioration. Trabecular bone score (TBS) is a method complementary to DXA, providing additional information about trabecular bone structure. The aim of this study was to assess the clinical utility of TBS in fracture risk assessment of patients treated with glucocorticoids. Patients with rheumatic diseases treated with glucocorticoids for at least 3 months were enrolled. All recruited patients underwent DXA with additional TBS assessment. We analyzed the frequency of osteoporosis and osteoporotic fractures and assessed factors that might be associated with the risk of osteoporotic fractures. A total of 64 patients were enrolled. TBS and TBS T-score values were significantly lower in patients with osteoporosis compared to patients without osteoporosis. Low energy fractures occurred in 19 patients. The disturbed bone microarchitecture was found in 30% of patients with fractures without osteoporosis diagnosis based on BMD. In the multivariate analysis, only TBS and age were significantly associated with the occurrence of osteoporotic fractures. TBS reflects the influence of glucocorticoid therapy on bone quality better than DXA measured BMD and provides an added value to DXA in identifying the group of patients particularly prone to fractures.