Improvement of osteoblast adhesion, viability, and mineralization by restoring the cell cytoskeleton after bisphosphonate discontinuation in vitro.

OBJECTIVE: Bisphosphonates are prescribed to treat excessive bone resorption in patients with osteoporosis. However, its use is associated with potential adverse effects such as medication-related osteonecrosis of the jaw, prompting the introduction of the drug holiday concept in patients prior to dentoalveolar surgery. Furthermore, bisphosphonate discontinuation has been studied in vivo, in humans, and in animal models. However, it is not known whether this approach could affect bone cells in vitro. Therefore, the objective of this study was to investigate the potential effects of bisphosphonate discontinuation on pre-osteoblast and osteoblast activities in vitro. METHODOLOGY: Pre-osteoblasts (MC3T3) and osteoblasts were treated with bisphosphonate (alendronate) at concentrations of 1, 5, and 10 µM. Alendronate was then withdrawn at different time points. The negative control consisted of untreated cells (0 µM), while the positive control consisted of cells incubated with alendronate throughout the experiment. Cell viability, cell adhesion, cell cytoskeleton, mineralization, and gene expressions were investigated. RESULTS: Pre-osteoblasts and osteoblasts showed a decrease in cell viability after treatment with 5-10 µM alendronate for 4 days or longer. Two days of alendronate discontinuation significantly increased cell viability compared with the positive control. However, these levels did not reach those of the negative control. Bone nodule formation was reduced by alendronate. Discontinuation of alendronate regained bone nodule formation. Longer periods of discontinuation were more effective in restoring nodule formation than shorter periods. Addition of alendronate resulted in an increase in the percentage of dead cells, which, in turn, decreased when alendronate was discontinued. Alendronate affected the cell cytoskeleton by disassembling actin stress fibers. Cell adhesion and cell morphological parameters were also affected by alendronate. Discontinuation of alendronate restored cell adhesion and these parameters. Overall, the highest improvement after alendronate discontinuation was seen at 10 µM. However, alendronate treatment and discontinuation did not affect osteoblast gene expression. CONCLUSION: Discontinuation of alendronate helps to reverse the negative effects of the drug on cell viability, cell adhesion, and mineralization by restoring the cell cytoskeleton. Our data suggest the benefits of drug holiday and/or intermittent strategies for alendronate administration at the cellular level.

Farnesyl Diphosphate Synthase Gene Associated with Loss of Bone Mass Density and Alendronate Treatment Failure in Patients with Primary Osteoporosis.

Aminobisphosphonates (NBPs) are the first-choice medication for osteoporosis (OP); NBP treatment aims at increasing bone mineral density (BMD) by inhibiting the activity of farnesyl diphosphate synthase (FDPS) enzyme in osteoclasts. Despite its efficacy, inadequate response to the drug and side effects have been reported. The A allele of the rs2297480 (A > C) SNP, found in the regulatory region of the FDPS gene, is associated with reduced gene transcription. This study evaluates the FDPS variant rs2297480 (A > C) association with OP patients' response to alendronate sodium treatment. A total of 304 OP patients and 112 controls were enrolled; patients treated with alendronate sodium for two years were classified, according to BMD variations at specific regions (lumbar spine (L1-L4), femoral neck (FN) and total hip (TH), as responders (OP-R) (n = 20) and non-responders (OP-NR) (n = 40). We observed an association of CC genotype with treatment failure (p = 0.045), followed by a BMD decrease in the regions L1-L4 (CC = -2.21% ± 2.56; p = 0.026) and TH (CC = -2.06% ± 1.84; p = 0.015) after two years of alendronate sodium treatment. Relative expression of the FDPS gene was also evaluated in OP-R and OP-NR patients. Higher expression of the FDPS gene was also observed in OP-NR group (FC = 1.84 ± 0.77; p = 0.006) when compared to OP-R. In conclusion, the influence observed of FDPS expression and the rs2897480 variant on alendronate treatment highlights the importance of a genetic approach to improve the efficacy of treatment for primary osteoporosis.

The effects of sodium alendronate on socket healing after tooth extraction: a systematic review of animal studies.

The aim of this systematic review was to answer the following question: "Does alendronate, a nitrogen-containing bisphosphonate, improve or impair alveolar socket healing after tooth extraction in animal models"? To this end, a systematic review of the literature was carried out in PubMed, Scopus, LILACS, Web of Science, as well as in the gray literature up to May 2023. Preclinical studies that evaluated alveolar healing after tooth extraction and the intake of sodium alendronate compared with placebo were included. Two investigators were responsible for screening the articles independently, extracting the data, and assessing their quality through the SYRCLE's RoB tool for randomized trials in animal studies. The study selection process, study characteristics, risk of bias in studies, impact of alendronate on bone healing, and certainty of evidence were described in text and table formats. Methodological differences among the studies were restricted to the synthesis methods. The synthesis of qualitative results followed the Synthesis Without Meta-analysis (SWiM) reporting guideline. From the 19 included studies, five were considered to have low risk, three were of unclear risk, and eleven presented a high risk of bias. The studies were considered heterogeneous regarding alendronate posology, including its dosage and route of administration. Furthermore, a variety of animal species, different age ranges, diverse teeth extracted, and exposure or not to ovariectomy contributed to the lack of parity of the selected studies. Our results indicated that alendronate monotherapy negatively affects the early phase of wound healing after tooth extraction in preclinical studies, suggesting that the bone resorption process after tooth extraction in animals treated with alendronate might impair the bone healing process of the extraction socket. In conclusion, alendronate administration restrains bone resorption, thereby delaying alveolar socket healing . Future studies should be conducted to validate these findings and to better understand the effects of alendronate therapy on oral tissues.

Rodents as an animal model for studying tooth extraction-related medication-related osteonecrosis of the jaw: assessment of outcomes.

OBJECTIVE: To assess the outcomes of several rodent animal models for studying tooth extraction-related medication-related osteonecrosis of the jaw (MRONJ). DESIGN: After a search of the databases, 2004 articles were located, and 118 corroborated the inclusion factors (in vivo studies in rodents evaluating tooth extraction as a risk factor for the development of MRONJ). RESULTS: Numerous studies attempting to establish an optimal protocol to induce MRONJ were found. Zoledronic acid (ZA) was the most used drug, followed by alendronate (ALN). Even when ZA did not lead to the development of MRONJ, its effect compromised the homeostasis of the bone and soft tissue. The association of other risk factors (dexamethasone, diabetes, and tooth-related inflammatory dental disease) besides tooth extraction also played a role in the development of MRONJ. In addition, studies demonstrated a relationship between cumulative dose and MRONJ. CONCLUSIONS: Both ZA and ALN can lead to MRONJ in rodents when equivalent human doses (in osteoporosis or cancer treatment) are used. Local oral risk factors and tooth-related inflammatory dental disease increase the incidence of MRONJ in a tooth extraction-related rodent model.

Long-term consequences of osteoporosis therapy with bisphosphonates.

Bisphosphonates (BPs) are medications widely used in clinical practice to treat osteoporosis and reduce fragility fractures. Its beneficial effects on bone tissue have been consolidated in the literature for the last decades. They have a high affinity for bone hydroxyapatite crystals, and most bisphosphonates remain on the bone surface for a long period of time. Benefits of long-term use of BPs: Large and important trials (Fracture Intervention Trial Long-term Extension and Health Outcomes and Reduced Incidence with Zoledronic acid Once Yearly-Pivotal Fracture Trial) with extended use of alendronate (up to 10 years) and zoledronate (up to 6 years) evidenced significant gain of bone mineral density (BMD) and vertebral fracture risk reduction. Risks of long-term use of BPs: The extended use of antiresorptive therapy has drawn attention to two extremely rare, although severe, adverse events. That is, atypical femoral fracture and medication-related osteonecrosis of the jaw are more common in patients with high cumulative doses and longer duration of therapy. BPs have demonstrated safety and effectiveness throughout the years and evidenced increased BMD and reduced fracture risks, resulting in reduced morbimortality, and improved quality of life. These benefits overweight the risks of rare adverse events.

A Case Report of Oral Bisphosphonate Treatment for Osteoporosis Leading to Atypical Femoral Fracture and Pathologic Mandibular Fracture.

BACKGROUND Bisphosphonates inhibit bone resorption in patients with postmenopausal osteoporosis and reduce osteoporotic fracture incidence. Medication-related osteonecrosis of the jaws (MRONJ) and atypical femoral fractures (AFF) are both rare but serious adverse effects of anti-resorptive drugs (ARD) such as bisphosphonates. The most advanced form of MRONJ is termed stage 3 and can lead to severe local sequelae like pathologic mandibular fractures (PMF). This study reports a case of MRONJ-related PMF and AFF with osteomyelitis secondary to bisphosphonate treatment for osteoporosis. CASE REPORT A 63-year-old white woman was diagnosed with PMF related to MRONJ stage 3 during treatment of an AFF with osteomyelitis. She had been treated for postmenopausal osteoporosis with 70 mg of alendronate weekly for 2 years. The PMF was treated by stable internal fixation combined with debridement and sequestrectomy, but further debridement was required and 2 mandibular implants were then removed. Postoperative recovery was uneventful and the mandibular infection was controlled after the second surgery. Three weeks later, she was discharged from the hospital, instructed to discontinue the use of alendronate, and referred for 30 sessions of hyperbaric oxygen therapy. At the 3-year follow-up, the PMF was completely healed without signs of mandibular infection or bone exposure. CONCLUSIONS This report raises awareness of both MRONJ and AFF as possible adverse effects of short-term bisphosphonate therapy for postmenopausal osteoporosis, and highlights the importance of dental and orthopedic follow-ups. It is crucial to emphasize the need for early diagnosis and treatment to prevent MRONJ progression to PMF.

Alendronate induces skeletal alterations in the chicken embryonic development model.

Alendronate, a nitrogen-containing bisphosphonate, has reported long-term clinical success in the management of distinct bone-related conditions, particularly in the modulation of post-menopausal osteoporosis. Nonetheless, whether the inhibitory activity over osteoclastic cells' functionality is widely acknowledged, contradictory evidence arises from the assessment of alendronate activity over osteoblastic populations. This may be of particular relevance in situations in which bone formation exceeds bone resorption, with further emphasis on embryonic development, since alendronate can cross the placental barrier and alendronate-based therapies are being extended into women of reproductive age. Accordingly, the present study aims to assess the effects of alendronate, at distinct concentrations (1.5E-10M to 1.5E-7M) on bone tissue development, within a translational animal model - the embryonic chicken development model. Embryos, at the beginning of osteogenesis (day 7) were exposed to different alendronate concentrations for 4 days. Embryos were following characterized for skeletal development by histomorphometric analysis upon histochemical staining, microtomographic analysis, and gene expression assessment of genes related to osteoclastogenic/osteoclastic and osteoblastogenic/osteogenic differentiation, as well as to the immuno-inflammatory activation. The findings revealed that exposure to alendronate had a dose-dependent impact on skeletal growth and mineralization. This effect was evidenced by diminished bone volume and reduced bone surface parameters, with the 1.5E-7M concentration leading to a remarkable reduction of over 50%. Additionally, a decreased osteoclastogenic/osteoclastic gene expression was verified, associated with a diminished osteoblastogenic/osteogenic program - within the 30-50% range for 1.5E-7 M, supporting the diminished bone formation process. An increased inflammatory activation may contribute, at least in part, to the attained outcomes. Overall present findings suggest a negative influence of alendronate on the embryonic bone development process in a dose-dependent manner, highlighting the potential risk of alendronate use during embryonic development.

Sodium alendronate is an effective adjunctive therapy for treating periodontitis in male rats treated with anticancer chemotherapy.

OBJECTIVES: To assess sodium alendronate as a local adjunctive therapy for treating experimental periodontitis in male rats treated with chemotherapy. DESIGN: One-hundred-eighty male rats were randomly divided into two groups (n = 90) based on the systemic treatments: PSS, physiological saline solution; and 5-Fluorouracil, and then, subdivided into three subgroups (n = 30): NT, no treatment; scaling and root planing; and sodium alendronate. Treatments were performed 7 days after induction of experimental periodontitis. Specimens were collected at 14, 22, and 37 days after induction. Alveolar bone level, percentage of bone in the furcation, percentage of non-vital bone in the furcation, histopathologic features, and immunolabeling pattern for tartrate-resistant acid phosphatase (TRAP) and osteocalcin (OCN) were evaluated. RESULTS: The lowest amount of alveolar bone and highest amount of non-vital bone was found in group 5-Fluorouracil when no treatment was performed. In animals receiving 5-Flurouracil and subjected to periodontal treatment, adjunctive sodium alendronate resulted in higher percentage of bone in the furcation and higher alveolar bone loss, when compared with scaling and root planing alone. Better structural and cellularity patterns were found in the periodontal tissues when sodium alendronate was used, regardless of systemic treatment. Higher TRAP-expression was found when no treatment was performed. Sodium alendronate didn't affect the immunolabeling pattern of osteocalcin in the presence of 5-Fluorouracil. CONCLUSION: Adjunctive therapy with local sodium alendronate prevented alveolar bone loss and improved the histopathological features of the periodontal tissues following scaling and root planing in male rats with experimental periodontitis receiving anticancer chemotherapy with 5-Fluorouracil.

Histological Evaluation of the Effect of Alendronate on the Maxillary Bone of Wistar Rats Combined with Orthodontic Movement of Intense Force / Evaluación Histológica del Efecto del Alendronate en el Hueso Maxilar de Ratas Wistar Combinado con Movimiento de Ortodoncia de Fuerzas Intensas

SUMMARY: To evaluate the histological adverse effects of alendronate administered systemically and topically in combination with orthodontic movement by intense force. Thirty-six 24-week-old female Wistar rats, ovariectomized, were used and divided into three groups (n = 12/group): control, locally treated with saline (0.07 ml/kg/week) (group 1) and experimental, treated with alendronic acid systemically (0.07 mg/kg/week) (group 2) and locally (7 mg/kg/week) (group 3). At 14 days, an orthodontic anchor was installed in the right first molar, and a force of 144 cN was applied for 28 days. The samples were processed for histological evaluation. Descriptive statistics, Shapiro-Wilk tests, one-way ANOVA with Bonferroni correction, one-way repeated measures ANOVA and chi-square tests were performed. All tests were statistically significant at p <0.05. The adverse events found in all groups were inflammation and osteoclastic activity. In the bisphosphonate-treated groups, there were statistically significant differences (p = 0.005) in the osteoclastic activity between the two hemiarcates. All rats in group 2 presented paralytic ileus. Compared to local administration, systemic treatment with alendronic acid produces more adverse effects, such as inflammation, fibrinoid necrosis, and osteoclastic activity. During the application of intense forces, it was not possible to show that there is necrosis associated with bisphosphonates.

Evaluar los efectos adversos histológicos del alendronato administrado sistémica y tópicamente en combinación con movimientos ortodóncicos de fuerza intensa. Treinta y seis ratas Wistar hembras de 24 semanas de edad, ovariectomizadas, fueron utilizadas y divididas en tres grupos (n = 12/grupo): control, tratado localmente con solución salina (0,07 ml/kg/semana) (grupo 1) y experimental, tratados con ácido alendrónico por vía sistémica (0,07 mg/kg/semana) (grupo 2) y local (7 mg/kg/semana) (grupo 3). A los 14 días se instaló un anclaje de ortodoncia en el primer molar derecho y se aplicó una fuerza de 144 cN durante 28 días. Las muestras fueron procesadas para evaluación histológica. Se realizó estadística descriptiva, pruebas de Shapiro-Wilk, ANOVA de una vía con corrección de Bonferroni, ANOVA de medidas repetidas de una vía y pruebas de chi-cuadrado. Todas las pruebas fueron estadísticamente significativas con un p <0,05. Los eventos adversos encontrados en todos los grupos fueron inflamación y actividad osteoclástica. En los grupos tratados con bisfosfonatos hubo diferencias estadísticamente significativas (p = 0,005) en la actividad osteoclástica entre los dos hemiarcados. Todas las ratas del grupo 2 presentaron íleo paralítico. En comparación con la administración local, el tratamiento sistémico con ácido alendrónico produce más efectos adversos, como inflamación, necrosis fibrinoide y actividad osteoclástica. Durante la aplicación de fuerzas intensas, no fue posible demostrar que existe necrosis asociada con los bisfosfonatos.

Effects of red and infrared laser on post extraction socket repair in rats subjected to alendronate therapy.

This study evaluated the effect of photobiomodulation therapy (PBMT) with a red or infrared laser on the repair of post extraction sockets in rats administered alendronate (ALN). Forty male rats were randomly allocated into four groups: Control Group (CTR): subcutaneous administration of saline solution throughout the experimental period; Alendronate Group (ALN): subcutaneous administration of alendronate during the entire experimental period; Alendronate/Red Laser Group (ALN/RL): administration of ALN and irradiation with a GaAlAs laser (λ 660 nm); and Alendronate/Infrared Laser Group (ALN/IRL): administration of ALN and irradiation with a GaAlAs laser (λ 830 nm). The first lower molars were extracted 60 days after the beginning of the administration of the drugs. The PBMT was applied after tooth extraction (7 sessions with intervals of 48 hours between sessions). Thirty days after tooth extraction, the animals were euthanized. Micro-CT and histometric analysis were performed to assess the bone healing and soft tissue repair of the tooth socket. The ALN group presented with more bone than the CTR; however, most of this bone was necrotic. ALN does not affect the bone microarchitecture. On the other hand, PBMT with IRL enhances the bone density due to the increase in the number and reduction in the spacing of the trabeculae. The amount of vital bone and connective tissue matrix was higher in the ALN/RL and ALN/IRL groups than in the ALN and CTR groups. PBMT enhanced the healing of the post extraction sockets in rats subjected to ALN administration. Furthermore, IRL improved the new bone microarchitecture.

Influence of the Osteogenomic Profile in Response to Alendronate Therapy in Postmenopausal Women with Osteoporosis: A Retrospective Cohort Study.

BACKGROUND: Postmenopausal osteoporosis is a multifactorial disease. Genetic factors play an essential role in contributing to bone mineral density (BMD) variability, which ranges from 60 to 85%. Alendronate is used as the first line of pharmacological treatment for osteoporosis; however, some patients do not respond adequately to therapy with alendronate. AIM: The aim of this work was to investigate the influence of combinations of potential risk alleles (genetic profiles) associated with response to anti-osteoporotic treatment in postmenopausal women with primary osteoporosis. METHODS: A total of 82 postmenopausal women with primary osteoporosis receiving alendronate (70 mg administered orally per week) for one year were observed. The bone mineral density (BMD; g/cm2) of the femoral neck and lumbar spine was measured. According to BMD change, patients were divided into two groups: responders and non-responders to alendronate therapy. Polymorphic variants in CYP19, ESR1, IL-6, PTHR1, TGFß, OPG and RANKL genes were determined and profiles were generated from the combination of risk alleles. RESULTS: A total of 56 subjects were responders to alendronate and 26 subjects were non-responders. Carriers of the G-C-G-C profile (constructed from rs700518, rs1800795, rs2073618 and rs3102735) were predisposed to response to alendronate treatment (p = 0.001). CONCLUSIONS: Our findings highlight the importance of the identified profiles for the pharmacogenetics of alendronate therapy in osteoporosis.

Vascular response to stress: Protective action of the bisphosphonate alendronate.

BACKGROUND: Since several additional actions of bone bisphosphonates have been proposed, we studied the effect of the bisphosphonate alendronate (ALN) on the vascular response to environmental stress. METHODS: Primary cultures of endothelial cells (EC) and vascular smooth muscle cells (VSMC) exposed to strained conditions were employed for experimental evaluation. After ALN treatment, cell migration, proliferation, and angiogenesis assays were performed. The participation of signal transduction pathways in the biochemical action of ALN was also assessed. RESULTS: In VSMC cultures, ALN counteracted the stimulation of cellular migration elicited by the proinflammatory agent lipopolysaccharide (LPS) or by high levels of calcium and phosphorus (osteogenic medium). Indeed, ALN reduced the increase of VSMC proliferation evoked by the stressors. When LPS and osteogenic medium were added simultaneously, the enhancement of cell proliferation dropped to control values in the presence of ALN. The mechanism of action of ALN involved the participation of nitric oxide synthase, mitogen-activated protein kinase (MAPK), and protein kinase C (PKC) signaling pathways. The study revealed that ALN exhibits a proangiogenic action. On EC, ALN enhanced vascular endothelial growth factor (VEGF) synthesis, and induced capillary-like tube formation in a VEGF-dependent manner. The presence of vascular stress conditions (LPS or osteogenic medium) did not modify the proangiogenic action elicited by ALN. CONCLUSION: The findings presented suggest an extra-bone biological action of ALN, which could contribute to the maintenance of vascular homeostasis avoiding cellular damage elicited by environmental stress.

Effect of resistance training combined with ß-glucan ingestion on bone of ovariectomized mice.

OBJECTIVE: This study aimed to evaluate the effects of resistance training (RT) combined with prebiotic ß-glucan (BG) ingestion (Saccharomyces cerevisiae) in ovariectomized (OVX) mice. METHODS: Forty-eight mice were divided into six treatments: SHAM group and five OVX groups treated with saline (SAL), alendronate (ALE) (0.1 mg/kg), BG (62.5 mg/kg), RT (climbing a ladder with load) and the combination of BG + RT. All treatments were performed three times per week for 8 weeks starting 38 days after ovariectomy. RESULTS: OVX effectiveness was confirmed by a reduction in uterus mass (p < 0.05). Femur weight was higher in the SHAM group, followed by the ALE and RT groups with intermediate values and the BG + RT, BG and SAL groups with the lowest values (p < 0.05). The bone mineral density (BMDDEXA) results were higher for the SHAM and RT groups compared to the other groups (p < 0.05). RT provided similar bone mass and resistance to fracture to ALE and SHAM. We found a similar number of osteocytes in the RT and SHAM groups, which was significantly higher than that found in animals receiving BG (p < 0.05). The BG + RT combination increased calcium bone concentration. CONCLUSION: RT promoted benefits on bone health in the OVX model, which were not complemented by the consumption of BG.

Denosumabe e teriparatida para o tratamento indivíduos com osteoporose grave e falha terapêutica aos medicamentos disponíveis no Sistema Único de Saúde / Denosumab and teriparatide for the treatment of individuals with severe osteoporosis and therapeutic failure to the drugs available in the Unified Health System

INTRODUÇÃO: A osteoporose, doença que aumenta da fragilidade óssea e suscetibilidade à fratura, afeta cerca de 200 milhões de pessoas no mundo. No geral, a prevalência de osteoporose em estudos brasileiros varia de 6% a 33% dependendo da população e outras variáveis avaliadas. Entre os indivíduos com osteoporose, aqueles que apresentaram fratura osteoporótica têm duas vezes o risco para nova fratura. Para evitar novas fraturas, o tratamento preconizado deve incluir estratégias medicamentosas e não medicamentosas. Entre as medicamentosas, suplementação de cálcio e colecalciferol, alendronato, risedronato, pamidronato, raloxifeno, calcitonina e estrógenos conjugados são opções disponíveis no Protocolo Clínico de Diretrizes Terapêuticas (PCDT) de Osteoporose do Sistema Único de Saúde (SUS). Apesar da disponibilidade de tratamentos, estima-se que 25% dos pacientes continuam a apresentar falha terapêutica aos tratamentos disponíveis. Nesse contexto, as diretrizes clínicas nacionais e internacionais de sociedade médicas, recomendam o uso de denosumabe ou teriparatida a pacientes com osteoporose grave e falha terapêutica aos medicamentos disponíveis no SUS (alendronato, pamidronato, raloxifeno e risedronato). Entretanto, há incerteza se os benefícios identificados para população em tratamento de primeira linha, principal população incluída nos estudos, são sustentados em população com osteoporose grave e falha terapêutica em vigência de tratamento; e se a escolha, por estas opções terapêuticas, pode valer a pena e ser viável economicamente para o SUS. Assim, o objetivo do presente relatório é analisar as evidências científicas sobre eficácia, efetividade, segurança, bem como evidências econômicas do denosumabe e da teriparatida para o tratamento de pacientes com osteoporose grave com falha terapêutica aos medicamentos disponíveis no SUS (alendronato, pamidronato, raloxifeno e risedronato). TECNOLOGIAS: Denosumabe (Prolia®) e teriparatida (Fortéo®). PERGUNTA: Os medicamentos denosumabe e

Histomorphometry of Bone Microarchitecture in Rats Treated with Vitamin D and Bisphosphonate in the Management of Osteoporosis / Histomorfometria da microarquitetura óssea em ratas tratadas com vitamina D e bisfosfonato no manejo da osteoporose

Abstract Objective To verify how the combined administration of alendronate (ALN) and vitamin D3 (VD) acts on the bone microarchitecture in rats with glucocorticoid-induced osteoporosis. Methods The experiment used 32 90-day-old female Wistar rats weighing between 300 and 400g. The induction of osteoporosis consisted of intramuscular administration of dexamethasone at a dose of 7.5 mg/kg of body weight once a week for 5 weeks, except for the animals in the control group. The animals were separated into the following groups: G1 (control group without osteoporosis), G2 (control group with osteoporosis without treatment), G3 (group with osteoporosis treated with ALN 0.2 mg/kg), G4 (group with osteoporosis treated with VD 10,000UI/500μL), and G5 (group with osteoporosis treated with ALN þ VD). The right femurs of the rats were fixed in 10% buffered formaldehyde, decalcified, and processed for inclusion in paraffin. Histological sections were stained with hematoxylin-eosin for histomorphometric analysis. Cortical thickness and medullary cavity were measured in cross-sections. Results There was a statistical difference (p< 0.05) between groups G3 and G5 compared with the positive control group (G2), both related to the measurement of cortical thickness and to the total diameter of the bone. In the evaluation of the spinal area, only the G3 group has shown to be statistically different from the G2 group. Conclusion Concomitant treatment with daily ALN and weekly VD is effective in preventing glucocorticoid-induced bone loss. However, there was no difference between the therapy tested and treatment with ALN alone.

Resumo Objetivo Verificar como a administração conjunta de alendronato de sódio (ALN) e vitamina D3 (VD) atua na microarquitetura óssea em ratas com osteoporose induzida por glicocorticoide. Métodos O experimento utilizou 32 ratas da linhagem Wistar, com peso médio de 300 a 400g, com 90 dias de vida. A indução da osteoporose consistiu na administração de dexametasona na dose de 7,5 mg/kg de peso corporal, por via intramuscular, 1 vez por semana durante 5 semanas, à exceção dos animais do grupo controle. Os animais foram distribuídos nos seguintes grupos: G1 (grupo controle sem osteoporose), G2 (grupo controle com osteoporose sem tratamento), G3 (grupo com osteoporose tratado com ALN 0,2 mg/kg), G4 (grupo com osteoporose tratado com VD 10.000UI/500μL) e G5 (grupo com osteoporose tratado com ALN þ VD). Os fêmures direitos das ratas foram fixados em formol a 10% tamponado, descalcificados e processados para inclusão em parafina. Os cortes histológicos foram corados com hematoxilina-eosina para análise histomorfométrica. A espessura cortical e a cavidade medular foram medidas em cortes transversais. Resultados Houve diferença estatística (p< 0,05) entre os grupos G3 e G5 em relação ao grupo controle positivo (G2), tanto em relação à medida da espessura cortical quanto em relação ao diâmetro total do osso. Na avaliação da área medular, apenas o grupo G3 se mostrou estatisticamente diferente do grupo G2. Conclusão O tratamento concomitante com ALN diário e VD semanal é eficaz para prevenir a perda óssea induzida por glicocorticoide. No entanto, não houve diferença entre esta terapia testada e o tratamento apenas com o ALN.

Strontium ranelate improves post-extraction socket healing in rats submitted to the administration of bisphosphonates.

The aim of this study was to evaluate the effect of strontium ranelate (Sr) on post-extraction socket healing in rats submitted to the administration of bisphosphonates. Sixty rats were submitted to the tooth extraction of the first lower molar after 60 days of the daily administration of saline solution (SS) or alendronate (ALN). Then, the animals were allocated into six groups namely CTR: administration of SS during the whole experiment, ALN: administration of ALN during the whole experiment, ALN/SS: application of SS for 30 days after extraction in animals previously treated with ALN, ALN/Sr: application of Sr for 30 days after extraction in animals previously treated with ALN, ALN/S60: ALN therapy interruption 30 days before the extraction followed by the application of SS for 60 days, and ALN/Sr60: ALN therapy interruption 30 days before the tooth extraction followed by the application of Sr for 60 days. The healing of the post-extraction sockets was evaluated by microCT and histomorphometry. The use of ALN induced partial bone necrosis, inflammatory infiltration, and a delay in soft tissue healing; the use of Sr improved the connective tissue organization. Sr has subtle positive effects on the post-extraction healing in animals submitted to the administration of bisphosphonate.

Effects of Alendronate and Dexamethasone on Osteoclast Gene Expression and Bone Resorption in Mouse Marrow Cultures.

Osteoclasts are cells whose main function is the resorption of bone matrix. However, several factors, including medications, can interfere with the resorption process. Alendronate (ALN), a nitrogen-containing type of bisphosphonate, and dexamethasone (DEX), a glucocorticoid, are drugs that may affect the resorption activity. The aim of this study is to investigate the effects of ALN, and/or DEX on osteoclast gene expression and resorption activity in primary mouse marrow cultures stimulated with 1,25-dihydroxyvitamin D3, a model for the bone microenvironment. Cultures were treated only with ALN (10-5 M), DEX (10-6 M), and with a combination of both agents. Viability assays performed at days 5, 7, and 9 showed the highest number of viable cells at day 7. All the following assays were then performed at day 7 of cell culture: tartrate resistant acid phosphatase (TRAP) histochemistry, receptor activator of nuclear factor kappa B ligand (RANKL) immunofluorescence, osteoprotegerin (OPG), and RANKL gene expression by qPCR and resorption analysis by scanning electron microscopy. Treatment with ALN, DEX, and the combination of both did not promote significant changes in the number of TRAP+ cells, although larger giant cells were detected in groups treated with DEX. DEX treatment increased the gene expression of RANKL and reduced OPG. The treatment with ALN reduced the depth of the resorption pits, but their inhibitory effect was less effective when administered with DEX.

Alendronato de sódio e vitamina D na osteoporose pós-menopausa: revisão sistemática / Alendronate sodium and vitamin D in postmenopausal osteoporosis: a systematic review

Objetivo: avaliar a eficácia da utilização da terapia combinada de alendronato de sódio e vitamina D no metabolismo ósseo de mulheres em tratamento de osteoporose pós-menopausa. Métodos: trata-se de uma revisão sistemática, a qual foram pesquisados ensaios clínicos randomizados (ECR) indexados nas bases de dados BVS, ISI Web of Science, PubMed, SciELO, ScienceDirect e Scopus que comparavam a associação de alendronato sódico e vitamina D com a monoterapia de alendronato de sódio. Resultados: um total de seis ECR contemplou os critérios para serem inclusos nesse estudo, compreendendo um total de 4164 participantes e seus respectivos dados. Os estudos avaliaram diferentes domínios do metabolismo ósseo, como níveis séricos de vitamina D, paratormônio, densidade mineral óssea e marcadores de turnover ósseo. A terapia combinada produziu melhora significativa nos marcadores metabólicos ósseos. Conclusão: a terapia combinada de alendronato de sódio com vitamina D promove melhora no metabolismo ósseo de mulheres com osteoporose pós-menopausa.

Aim: to evaluate the effectiveness of using the combined therapy of sodium alendronate and vitamin D on bone metabolism in women undergoing postmenopausal osteoporosis. Methods: this is a systematic review. The studies included were Randomized Controlled Trials (RCT) indexed in the BVS, ISI Web of Science, PubMed, SciELO, ScienceDirect and Scopus Databases which compared the association of sodium alendronate and vitamin D to monotherapy of sodium alendronate. Results: a total of six RCT met the criteria to be included in this study, comprising a total of 4164 participants and their respective data. The studies evaluated different domains of bone metabolism, such as serum levels of vitamin D, parathyroid hormone, bone mineral density and bone turnover markers. Combination therapy produced significant improvement in bone metabolic markers. Conclusion: combined therapy of sodium alendronate with vitamin D promotes improved bone metabolism in women with postmenopausal osteoporosis.

Alendronato de sódio tópico associado ao osso bovino liofilizado no reparo ósseo / Topical alendronate associated with lyophilized bovine bone in bone repair

Introdução: O osso bovino inorgânico é o enxerto mais utilizado na Odontologia, tendo como desvantagem longo tempo de integração ao leito receptor. Os bifosfonatos têm sido utilizados para modular a quantidade e a qualidade do osso regenerado e diminuir o tempo de integração do enxerto. Objetivo: Avaliar o efeito do bifosfonato alendronato de sódio (ALN) 0,5%, associado ou não ao osso bovino inorgânico, na reparação de defeitos ósseos. Material e método: Dois defeitos ósseos foram confeccionados na calvária de 12 coelhos, sendo a cavidade esquerda/experimental preenchida com: GI = osso bovino inorgânico (Bio-Oss®); GII = Bio-Oss® + ALN 0,5%; GIII = ALN 0,5%; e a cavidade direita por coágulo sanguíneo (controle). Os animais foram mortos aos 60 dias pós-operatórios. Por meio de análise histomorfométrica calculou-se o percentual de osso neoformado e remanescente do biomaterial em relação à área total do defeito. Resultado: Osso neoformado: GI = 38,16 ± 15,44%; GII = 55,77 ± 16,75%; GII I = 60,28 ± 11,45%. Controle = 45,11 ± 11,09%. Remanescente do enxerto: GI = 7,02 ± 5,36% e GII = 16,59 ± 9,56%. Não houve diferença quanto ao percentual de osso neoformado entre os grupos (ANOVA p = 0,15512; teste de Tukey F = 2,089). O percentual de remanescente do enxerto também foi estatisticamente semelhante entre os grupos GI e GII (teste de Tukey F = 5,019). Conclusão: O uso tópico da solução de ALN 0,5% isoladamente ou associado ao osso bovino liofilizado não alterou o percentual de neoformação óssea nem a degradação dos grânulos do enxerto.

Introduction: Inorganic bovine bone is the most used graft in dentistry, with the disadvantage of long integration time into the receptor bed. Bisphosphonates have been used to modulate the quantity and quality of regenerated bone and decrease graft integration time. Objective: To evaluate the effect of alendronate sodium bisphosphonate (ALN) 0.5%, associated or not with Inorganic bovine bone, in the repair of bone defects. Material and method Two bone defects were made in the calvaria of 12 rabbits, and the left/experimental cavity was filled with: GI = Inorganic bovine bone (Bio-Oss®); GII = Bio-Oss® + 0.5% ALN; GIII = 0.5% ALN; and the right cavity/blood clot control. The animals were killed at 60 days after surgery. Through histomorphometric analysis, the percentage of newly formed bone and remnant biomaterial relative to the total area of the defect was calculated. Result: Neoformed bone: GI = 38.16 ± 15.44%, GII = 55.77 ± 16.75%; GIII= 60.28 ± 11.45%; Control=45,11 ± 11,09%. Graft remnant: GI = 7.02 ± 5.36% and GII = 16.59 ± 9.56%. There was no difference in the percentage of newly formed bone between the groups (ANOVA p = 0.15512; Tukey's test F = 2.089). The percentage of graft remnant was also statistically similar between groups GI and GII (Tukey's test F = 5019). Conclusion: Topical use of 0.5% ALN solution alone or associated with lyophilized bovine bone did not change the percentage of bone neoformation, nor the degradation of graft granules.

Potential Alendronate Sodium drug carrier by preparation and characterization of sodium alginate cross-linked Montmorillonite

Abstract In drug therapy, it is important to provide therapeutic levels of drug to the site of action and maintain them during the treatment. This work describes the in vitro release of alendronate from sodium alginate cross-linked Montmorillonite (MMT) composite beads. Effect of crosslinking cation, concentration of montmorillonite and media on encapsulation efficiencies, and release profiles of alendronate were studied. Beads were characterized using equilibrium swelling ability study, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Energy-dispersive x-ray spectroscopy (EDX) and scanning electron microscopy (SEM). Results indicate that addition of montmorillonite increases the encapsulation efficiencies and slows down the release rates significantly.