Pharmacology of bisphosphonates

Bisphosphonates Trigger Anti-Ageing Effects Across Multiple Cell Types and Protect Against Senescence

Bisphosphonates (BPs) have been the major class of medicines used to treat disorders of excessive bone loss for over five decades. Recently it has been recognized that BPs may also have additional significant beneficial extra-skeletal effects. These include a reduction of all-cause mortality and of conditions commonly linked to ageing, such as cancer and cardiovascular disease. Here we show that bisphosphonates co-localize with lysosomal and endosomal organelles in non-skeletal cells and stimulate cell growth at low doses. In vivo spatial transcriptomic analysis revealed differentially expressed senescence markers in multiple organs of aged BP-treated mice, and a shift in cellular composition toward those of young counterparts. Similarly, a 5000-plex plasma proteome analysis from osteopenic patients before and after BP-treatment showed significant alterations in ∼400 proteins including GTPase regulators and markers of senescence, autophagy, apoptosis, and inflammatory responses. Furthermore, treatment with BPs protected against the onset of senescence in vitro . Proteome-wide target deconvolution using 2D thermal profiling revealed novel BP-binding targets (PHB2, ASAH1), and combined with RNA- and ATAC-seq of BP-treated cells and patient data, suggests downstream regulation of the MEF2A transcription factor within the heart. Collectively, these results indicate how BPs may beneficially modify the human plasma proteome, and directly impact multiple non-skeletal cell types through previously unidentified proteins, thereby influencing a range of pathways related to senescence and ageing.

Periprosthetic osteolysis: Mechanisms and potential treatment strategies

Periprosthetic osteolysis is a common bone-related disorder that often occurs after total hip arthroplasty. The implants can cause damage to bone and bone-related cells due to mechanical stress and micromotions, resulting in the generation of a large number of wear particles. These wear particles trigger inflammation and oxidative stress in the surrounding tissues, disrupting the delicate balance maintained by osteoblasts and osteoclasts, ultimately leading to bone loss around the implant. Clinical investigations have demonstrated that Epimedium prenylflavonoids, miR-19a-3p, stem cell-derived exosomes, and certain non-PPO category pharmaceuticals have regulatory effects on bone homeostasis through distinct molecular pathways. Notably, this phenomenon reflects inherent biological rationality rather than stochastic occurrence. Extensive research has revealed that multiple natural compounds, non-coding RNAs, exosomes, and non-PPO therapeutics not only exert modulatory influences on critical pathophysiological processes including inflammatory cascades, oxidative stress responses, and tissue regeneration mechanisms, but also effectively regulate bone-related cellular functions to inhibit PPO progression. Therefore, this review comprehensively and systematically summarizes the main pathogenic mechanisms of periprosthetic osteolysis. Furthermore, it delves deeper into the research progress on the applications of currently reported natural products, ncRNAs, exosomes, and non-PPO medications in the treatment of periprosthetic osteolysis. Based on this, we hope that this paper can provide new perspectives and references for the future development of drugs targeting periprosthetic osteolysis.

[Influencing fracture healing by specific osteoporosis medications]

BACKGROUND

Osteoporosis is a widespread disease defined by a reduction in bone mass and structure, thereby increasing the risk of fragility fractures. Treatment typically involves specific medications, which either inhibit bone resorption (antiresorptive) or stimulate bone formation (anabolic) and may potentially influence the healing of osteoporotic fractures. On the other hand, metabolic disorders, immune system dysfunctions or circulatory problems can impair fracture healing. Therefore, the targeted use of osteoporosis medications could be a strategy to promote the healing of impaired fractures.

OBJECTIVE

The aim of this study is to provide a current overview of the effects of osteoporosis medications approved in Germany on fracture healing. The focus is on the potential influence of these medications in the context of osteoporosis treatment. Additionally, the current state of research is examined to explore to what extent the targeted use of these medications could improve fracture healing.

MATERIAL AND METHODS

A literature search was conducted in the PubMed database using topic-specific keywords. Preclinical studies, clinical trials, review articles and meta-analyses were considered to present the current scientific knowledge with clinical relevance.

RESULTS

Preclinical and clinical studies suggest that specific osteoporosis medications do not have a clinically relevant negative impact on the healing of fragility fractures. Osteoanabolic substances even tend to have a positive effect on fracture healing in both normal and impaired healing processes; however, the available studies are limited and none of the medications have been approved for this specific use.

DISCUSSION

Osteoporosis medications with antiresorptive or osteoanabolic effects are primarily used to treat osteoporosis, especially after fragility fractures, to reduce the risk of further fractures. There is no clinically relevant impairment of fracture healing due to these medications. Further studies would be required to obtain approval for these medications specifically to improve fracture healing.

The Microbiological Background of Medication-Related Osteonecrosis of the Jaw (MRONJ): Clinical Evidence Based on Traditional Culture and Molecular Biological Detection Methods

Background: Medication-related osteonecrosis of the jaw (MRONJ) is a common adverse event following antiresorptive treatment, leading to chronic inflammation and exposed, necrotic bone surfaces in the jawbone. There is an increasing recognition of the role of compositional changes in the colonizing members of the oral microbiota implicated in triggering and/or maintaining MRONJ. The aim of our study was to characterize the culturable and non-culturable microbiota-with particular focus on Actinomyces spp. and Actinomyces-like organisms (ALOs)-from surgically removed bone samples of MRONJ patients and healthy control subjects. Methods: n = 35 patients (median age: 70 years) in various stages of MRONJ, with a history of receiving oral or intravenous antiresorptive treatment were included in the study. The controls (n = 35; median age: 35 years) consisted of otherwise healthy individuals undergoing tooth extraction. Traditional, quantitative, aerobic, and anaerobic culture, and Actinomyces-specific PCR was performed for all bone samples from patients and controls, while microbiome analyses-based on 16S rRNA sequencing-were carried out in 5-5 randomly selected samples. Mann-Whitney U test, Wilcoxon rank sum test (alpha diversity), and PERMANOVA analysis (beta diversity) were performed. Results: In MRONJ samples, 185 anaerobic isolates, corresponding to 65 different species were identified (vs. 72 isolates, corresponding to 27 different species in the control group). The detection of Actinomyces spp. and ALOs was more common in MRONJ bone samples, based on traditional culture (65.7% vs. 17.1%; p < 0.001) and PCR (82.9% vs. 37.1%; p < 0.001), respectively. The isolation of Fusobacterium spp. (22 vs. 7; p = 0.001), Prevotella spp. (22 vs. 6; p = 0.034), and Gram-positive anaerobic cocci (GPAC) (30 vs. 9; p = 0.016) was significantly more common in MRONJ patient samples. The microbiota of the controls' bone samples were characterized by a considerable dominance of Streptococcus spp. and Veillonella spp, while the bacterial abundance rates were substantially more heterogeneous in MRONJ bone samples. Notable differences were not observed among the samples related to the abundance of Actinomyces in the bone microbiota. Conclusions: According to the "infection hypothesis", alterations in the oral microbiome-with Actinomyces and ALOs being the most relevant-may play a key role in the development, aggravation, and progression of MRONJ. The timely detection of Actinomyces in necrotic bone is crucial, as it has important therapeutic implications.

Current and emerging bone resorption inhibitors for the treatment of osteoporosis

INTRODUCTION

Osteoporosis is a metabolic skeletal disease characterized by low bone mass and strength, and increased risk for fragility fractures. It is a major health issue in aging populations, due to fracture-associated increased disability and mortality. Antiresorptive treatments are first line choices in most of the cases.

AREAS COVERED

Bone homeostasis is complicated, and multiple factors can compromise skeletal health. Bone turnover is a continuous process regulated by the coupled activities of bone cells that preserves skeletal strength and integrity. Imbalance between bone resorption and formation leads to bone loss and increased susceptibility to fractures. Antiresorptives prevent bone loss and reduce fracture risk, by targeting osteoclastogenesis and osteoclast function and survival. Their major drawback is the coupling of osteoclast and osteoblast activity, due to which any reduction in bone resorption is followed by suppression of bone formation.

EXPERT OPINION

During the last couple of decades significant progress has been made in understanding of the genetic and molecular basis of osteoporosis. Critical pathways and key molecules that mediate regulation of bone resorption have been identified. These factors may underpin novel therapeutic avenues for osteoporosis, but their potential for translation into clinical applications is yet to be tested.

Repurposing the familiar: Future treatment options against chronic kidney disease

OBJECTIVES

Chronic kidney disease (CKD) is a serious health issue with rising morbidity and mortality rates. Despite advances in understanding its pathophysiology, effective therapeutic options are limited, necessitating innovative treatment approaches. Also, current frontline treatments that are available against CKD are not uniformly effective and often come with significant side effects. Therefore, identifying new therapeutic targets or improving existing treatments for CKD is crucial. Drug repurposing is a promising strategy in the drug discovery process that involves screening existing approved drugs for new therapeutic applications.

KEY FINDINGS

This review discusses the pharmacological mechanisms and clinical evidence that support the efficacy of these repurposed drugs. Various drugs classes such as inodilators, endothelin-1 type A (ET-1A) receptor antagonists, bisphosphonates, mineralocorticoid receptor (MR) antagonists, DNA demethylating agents, nuclear factor erythroid 2-related factor 2 (NRF2) activators, P2X7 inhibitors, autophagy modulators, hypoxia-inducible factor-prolyl hydroxylase inhibitors (HIF-PHI) are discussed that could remarkably contribute against CKD.

SUMMARY

The review critically examines the potential for repurposing well-established drugs to slow the progression of CKD and enhance patient outcomes. This review emphasizes the importance of a multidisciplinary approach in advancing the field of drug repurposing, ultimately paving the way for innovative and effective therapies for patients suffering from CKD.

Concomitant medication effects on patients with lung cancer taking immune checkpoint inhibitors a review

In the past decade, a variety of immune checkpoint inhibitors (ICIs) are currently approved for lung cancer in the world. As a new therapeutic approach, ICIs have shown significant clinical benefits in the first-line or second-line treatment for advanced lung cancer, improving the survival and quality of life of patients. Patients need to take multiple drugs in the meantime due to their own disease or side effects during treatment. In view of drug interactions, concomitant medications have a positive or negative impact on the prognosis of lung cancer patients. In this review, we reviewed the effects of multiple drugs on the prognosis of patients with lung cancer taking ICIs. Several studies indicate that antibiotics, proton pump inhibitors (PPIs), corticosteroids, and opioid analgesics can decrease the efficacy of ICIs. Aspirin and bone-targeting drugs can enhance the efficacy of ICIs and improve the survival rate. The effects of metformin (MET), renin-angiotensin-aldosterone system inhibitors (RASI), nonsteroidal anti-inflammatory drug (NSAIDS) (except aspirin), and statins on ICIs are controversial. Future research should further explore the effects of these concomitant medications on ICIs and develop personalized prescriptions based on the specific needs of patients.

Magnesium Nanocomposite Hydrogel Reverses the Pathologies to Enhance Mandible Regeneration

The healing of bone defects after debridement in medication-related osteonecrosis of the jaw (MRONJ) is a challenging medical condition with impaired angiogenesis, susceptible infection, and pro-inflammatory responses. Magnesium (Mg) nanocomposite hydrogel is developed to specifically tackle multiple factors involved in MRONJ. Mg-oxide nanoparticles tune the gelation kinetics in the reaction between N-hydroxysuccinimide-functionalized hyperbranched poly (ethylene glycol) and proteins. This reaction allows an enhanced mechanical property after instant solidification and, more importantly, also stable gelation in challenging environments such as wet and hemorrhagic conditions. The synthesized hydrogel guides mandible regeneration in MRONJ rats by triggering the formation of type H vessels, activating Osterix+ osteoprogenitor cells, and generating anti-inflammatory microenvironments. Additionally, this approach demonstrates its ability to suppress infection by inhibiting specific pathogens while strengthening stress tolerance in the affected alveolar bone. Furthermore, the enhanced osteogenic properties and feasibility of implantation of the hydrogel are validated in mandible defect and iliac crest defect created in minipigs, respectively. Collectively, this study offers an injectable and innovative bone substitute to enhance mandible defect healing by tackling multiple detrimental pathologies.

An insight into recent developments in imidazole based heterocyclic compounds as anticancer agents: Synthesis, SARs, and mechanism of actions

Among all non-communicable diseases, cancer is ranked as the second most common cause of death and is rising constantly. While cancer treatments mainly include radiation therapy, chemotherapy, and surgery; chemotherapy is considered the most commonly employed and effective treatment. Most of the chemotherapeutic agents are azoles based compounds and imidazole is one such insightful azole. The anticancer properties of imidazole-based compounds have been thoroughly explored in recent years and all monosubstituted, disubstituted, trisubstituted, and tetrasubstituted imidazoles have been explored for their anticancer activities. Along with these compounds, other imidazole-based compounds like 1,3-dihydro-2H-imidazole-2-thiones, imidazolones, and poly imidazole compounds have also been explored for their anticancer activities. The activities of these compounds are heavily influenced by their structural resemblance to combretastatin 4A and ABI (2-aryl-4-benzoyl-imidazole). The lead compounds were highly active on breast, gastric, colon, ovarian, cervical, bone marrow, melanoma, prostate, lung, leukemic, neuroblastoma, liver, Ehrlich, melanoma, and pancreatic cancers. The targets of these leads like tubulin, heme oxygenases, VEGF, tyrosine kinases, EGFR, and others have also been explored. The exploration of the anticancer potential of substituted imidazole compounds is the main topic of this review including synthesis, SAR, and mechanism.

Peri-operative zoledronic acid attenuates peri-prosthetic osteolysis in a rat model of cemented knee replacement

Progressive osteolysis can occur at the cement-bone interface of joint replacements and the associated loss of fixation can lead to clinical loosening. We previously developed a rat hemiarthroplasty model that exhibited progressive loss of fixation with the development of cement-bone gaps under the tibial tray that mimicked patterns found in human arthroplasty retrievals. Here we explored the ability of a bisphosphonate (zoledronic acid, ZA) to attenuate cement-bone osteolysis and maintain implant stability. Sprague-Dawley rats (n = 59) received a poly(methylmethacrylate) cemented tibial component and were followed for up to 12 weeks. Treatment groups included peri-operative administration of ZA (ZA group), administration of ZA at 6 weeks postop (late ZA group), or vehicle (Veh group). There was a 60% reduction in the rate of cement-bone gap formation for the ZA group (0.15 mm3/week) compared to Veh group (0.38 mm3/week, p = 0.016). Late ZA prevented further progression of gap formation but did not reverse bone loss to the level achieved in the ZA group. Micromotion from five times body weight toggle loading was positively correlated with cement-bone gap volume (p = 0.009) and negatively correlated with the amount of cement in the metaphysis (p = 0.005). Reduced new bone formation and enduring nonviable bone in the epiphysis for the ZA group were found. This suggests that low bone turnover in the epiphysis may suppress the early catabolic response due to implantation, thereby maintaining better fixation in the epiphysis. This preclinical model presents compelling supporting data documenting improved maintenance of the cement-bone fixation with the use of peri-operative bisphosphonates.

Harnessing curcumin and nanotechnology for enhanced treatment of breast cancer bone metastasis

Breast cancer (BC) bone metastasis poses a significant clinical challenge due to its impact on patient prognosis and quality of life. Curcumin (CUR), a natural polyphenol compound found in turmeric, has shown potential in cancer therapy due to its anti-inflammatory, antioxidant, and anticancer properties. However, its metabolic instability and hydrophobicity have hindered its clinical applications, leading to a short plasma half-life, poor absorption, and low bioavailability. To enhance the drug-like properties of CUR, nanotechnology-based delivery strategies have been employed, utilizing polymeric, lipidic, and inorganic nanoparticles (NPs). These approaches have effectively overcome CUR's inherent limitations by enhancing its stability and cellular bioavailability both in vitro and in vivo. Moreover, targeting molecules with high selectivity towards bone metastasized breast cancer cells can be used for site specific delivery of curcumin. Alendronate (ALN), a bone-seeking bisphosphonate, is one such moiety with high selectivity towards bone and thus can be effectively used for targeted delivery of curcumin loaded nanocarriers. This review will detail the process of bone metastasis in BC, elucidate the mechanism of action of CUR, and assess the efficacy of nanotechnology-based strategies for CUR delivery. Specifically, it will focus on how these strategies enhance CUR's stability and improve targeted delivery approaches in the treatment of BC bone metastasis.

Therapeutic effect of bloodletting on bone deterioration induced by hypobaric hypoxia in young rats

OBJECTIVES

High-altitude regions, comprising hypoxic condition, are associated with different altitude-induced pathologies, including a reduction in bone density. Elucidating the mechanisms underlying bone degradation in such environments and developing targeted interventions and therapeutics is important. Bloodletting therapy has promising clinical applications, but its effects on the skeletal system and bone homeostasis are not well understood. The aim of this study was to investigate the effects of a hypobaric hypoxia environment on specific femoral morphological and structural properties, including the bone volume, cortical thickness, and trabecular microarchitecture, in juvenile Sprague-Dawley (SD) rats, and to explore the potential modulating effects of a bloodletting intervention on these parameters.

METHODS

Male SD rats, 6 weeks of age, were subjected to a simulated hypobaric hypoxia environment, replicating a 5000-m altitude, for 12 weeks. For the bloodletting intervention group, rats were subjected to a weekly 500 μL tail vein blood withdrawal. Micro-CT technology, hematoxylin and eosin staining, and tartrate-resistant acid phosphatase staining were employed to comprehensively assess the femoral microstructure, tissue architecture, and cellular morphology. Additionally, immunofluorescence analysis was conducted to quantify the expression of key proteins, and transcriptome analysis was performed to identify differentially expressed genes.

RESULTS

Exposing rats to hypobaric hypoxia led to a significant reduction in the bone mineral content, trabecular bone number, and cortical bone thickness, suggesting a deterioration of bone microstructure. Additionally, the hypoxic environment upregulated the expression of RANKL and HIF-1α, while downregulating RUNX2 expression. Notably, although bloodletting intervention did not significantly reverse these bone structural changes, transcriptome analysis revealed its regulatory influence on the expression of key genes, particularly Mmp2, Fosl2, and URS0000B2A65A, which are implicated in pathways governing the hypoxic response, osteoclast differentiation, and PI3K-Akt signaling.

CONCLUSION

This study highlights the detrimental effect of hypobaric hypoxia on the bone microstructure of juvenile rats and underscores the therapeutic potential of bloodletting to ameliorate this condition. Additionally, our study on the regulatory mechanisms mediating the effects of bloodletting on gene expression offers new perspectives on bone alterations. It suggests promising avenues for the development of novel preventative measures and targeted therapies to address the challenges posed by related bone disorders.

Pamidronate for pain in adult chronic nonbacterial osteitis: protocol of a randomized, double-blind, placebo-controlled trial

Chronic nonbacterial osteitis (CNO) is a rare auto-inflammatory bone disease affecting children and adults. Adult CNO is characterized by painful bone lesions, primarily of the anterior chest wall. There is no approved therapy for adult CNO. Current off-label treatments include intravenous bisphosphonates, which have been shown to alleviate pain through decreasing bone turnover. However, no adequately powered randomized controlled trials (RCTs) have been conducted. This double-blind, placebo-controlled RCT investigates the efficacy of intravenous pamidronate to decrease bone pain in adult CNO patients. Recruiting at the Dutch national referral center for CNO, adult patients with persistent bone pain despite non-steroidal anti-inflammatory drugs, or optionally other standard-of-care treatments are randomized to receive two courses of intravenous pamidronate (at 0 and 3 mo, 30 mg daily, on 3 consecutive d) or placebo. From 6 mo onwards, all patients receive open-label pamidronate for another two courses. The primary outcome is change in score for maximum pain from 0 to 6 mo. Secondary outcomes include change in quantitative intralesional bone turnover as measured on sodium-fluoride positron emission computed tomography ([18F]NaF-PET/CT), inflammation markers, shoulder function, general health, quality of life, fatigue, physical, and work activity. The pamidronate for pain in adult chronic nonbacterial osteitis trial addresses the need for evidence-based treatments in adult CNO. Results will directly impact daily clinical practice, either validating the use of intravenous pamidronate in CNO at the dose used in this trial or prompting the search for alternative regimens or agents. This trial was registered in EudraCT (reference 2020-001068-27) and the Dutch Trial Register (reference NL68020.058.20).

Bisphosphonate Liposomes for Cobalt and Strontium Decorporation?

ABSTRACT

During a nuclear/radiological incident or an accident involving internal intakes with radioactive cobalt or strontium, the recommended treatments, consisting of the administration of diethylenetriaminepentaacetic acid for 60 Co and calcium gluconate for 90 Sr, are of low specificity, and their effectiveness can be enhanced. In this manuscript, a liposomal formulation was developed to deliver potential chelating agents to the main retention organs of both radionuclides. A bisphosphonate, etidronate, has been selected as a possible candidate due to its satisfying decorporation activity for uranium, bone tropism, and potential affinity with cobalt. Pre-clinical studies have been carried out on rats using radionuclide contamination and treatment administration by the intravenous route. The effectiveness of free or liposomal etidronate was evaluated, with an administration at 30 min, 48 h post-contamination with 60 Co. Regarding 85 Sr, a more extended experiment with etidronate liposomes was performed over 6 d. The results were compared to those performed with reference treatments, diethylenetriaminepentaacetic acid for cobalt and calcium gluconate for strontium. Unexpected results were found for the reference treatments that were significantly less effective than previously reported or showed no effectiveness. Free etidronate revealed no significant efficacy after 48 h, but the liposomal form suggested an interaction with radionuclides, not sufficient to change the biokinetics. This study emphasizes the need for early treatment administration and further research to provide a more effective medical countermeasure.

[Osteoporosis-Definition, risk assessment, diagnosis, prevention and treatment (update 2024) : Guidelines of the Austrian Society for Bone and Mineral Research]

BACKGROUND

Austria is among the countries with the highest incidence and prevalence of osteoporotic fractures worldwide. Guidelines for the prevention and management of osteoporosis were first published in 2010 under the auspices of the then Federation of Austrian Social Security Institutions and updated in 2017. The present comprehensively updated guidelines of the Austrian Society for Bone and Mineral Research are aimed at physicians of all specialties as well as decision makers and institutions in the Austrian healthcare system. The aim of these guidelines is to strengthen and improve the quality of medical care of patients with osteoporosis and osteoporotic fractures in Austria.

METHODS

These evidence-based recommendations were compiled taking randomized controlled trials, systematic reviews and meta-analyses as well as European and international reference guidelines published before 1 June 2023 into consideration. The grading of recommendations used ("conditional" and "strong") are based on the strength of the evidence. The evidence levels used mutual conversions of SIGN (1++ to 3) to NOGG criteria (Ia to IV).

RESULTS

The guidelines include all aspects associated with osteoporosis and osteoporotic fractures, such as secondary causes, prevention, diagnosis, estimation of the 10-year fracture risk using FRAX®, determination of Austria-specific FRAX®-based intervention thresholds, drug-based and non-drug-based treatment options and treatment monitoring. Recommendations for the office-based setting and decision makers and institutions in the Austrian healthcare system consider structured care models and options for osteoporosis-specific screening.

CONCLUSION

The guidelines present comprehensive, evidence-based information and instructions for the treatment of osteoporosis. It is expected that the quality of medical care for patients with this clinical picture will be substantially improved at all levels of the Austrian healthcare system.

Atypical Periprosthetic Femoral Fracture Might be Considered a Distinct Subtype of Atypical Femoral Fracture: A Retrospective Study

OBJECTIVE

The exact relationship among atypical periprosthetic femoral fractures (APFFs), typical periprosthetic femoral fractures (PFFs), and atypical femur fractures (AFFs) remains unclear. This study aimed to investigate the prevalence of APFFs among PFFs and to identify the clinical characteristics, management, and prognosis that distinguish APFFs from typical PFFs and AFFs to further determine the relationship among these three fracture types.

METHODS

In this retrospective study, we reviewed the clinical data of 117 consecutive patients who had PFFs after hip arthroplasty between January 2012 and December 2022 and further classified them into an APFF group and a typical PFF group according to the revised ASBMR diagnostic criteria for AFF. Moreover, patients who had subtrochanteric or femoral shaft fractures in the same period and met the diagnostic criteria for AFF were recruited and classified into the AFF group. Demographic information, minor features of AFF, comorbidities, history of medication usage, management, and complications were collected and compared among patients with typical PFFs, APFFs, and AFFs.

RESULTS

Eleven PFFs were identified as APFFs, and the prevalence of APFFs among PFFs was 9.4%. Significant differences were found in generalized increase in cortical thickness (p = 0.019), prodromal symptoms (p < 0.001), and the incidence of bilateral fractures (p = 0.010) among the groups, where the incidences of these minor features in the APFF group and the AFF group were higher than those in the typical PFF group. Of note, the duration of fracture healing of APFFs was significantly longer than that of typical PFFs and AFFs (p < 0.001 and p = 0.004, respectively). In addition, the APFF group and the AFF group had higher proportions of patients with rheumatoid arthritis (p = 0.004 and p = 0.027, respectively), bisphosphonate (BP) usage (p = 0.026 and p < 0.001, respectively), and longer duration of BP usage (p = 0.003 and p = 0.007, respectively) than the typical PFF group. Furthermore, significant differences were found in management (p < 0.001) and complication rate (p = 0.020) among the groups, and the rate of complications in the APFF group and the AFF group was higher than that in the typical PFF group.

CONCLUSIONS

APFFs not only fulfilled the mandatory and major diagnostic criteria for AFF but also had many clinical characteristics, management and prognosis distinguishing them from typical PFFs but resembling AFFs; hence, the diagnostic criteria for AFF might be revised to incorporate APFF as a distinct subtype of the condition.

Amitotic Cell Division, Malignancy, and Resistance to Anticancer Agents: A Tribute to Drs. Walen and Rajaraman

Cell division is crucial for the survival of living organisms. Human cells undergo three types of cell division: mitosis, meiosis, and amitosis. The former two types occur in somatic cells and germ cells, respectively. Amitosis involves nuclear budding and occurs in cells that exhibit abnormal nuclear morphology (e.g., polyploidy) with increased cell size. In the early 2000s, Kirsten Walen and Rengaswami Rajaraman and his associates independently reported that polyploid human cells are capable of producing progeny via amitotic cell division, and that a subset of emerging daughter cells proliferate rapidly, exhibit stem cell-like properties, and can contribute to tumorigenesis. Polyploid cells that arise in solid tumors/tumor-derived cell lines are referred to as polyploid giant cancer cells (PGCCs) and are known to contribute to therapy resistance and disease recurrence following anticancer treatment. This commentary provides an update on some of these intriguing discoveries as a tribute to Drs. Walen and Rajaraman.

Influence of the use of bisphosphonates on the development of postextraction sequelae: Scoping review with mapping evidence of in vivo studies

OBJECTIVE

To map the current scientific landscape regarding the association/causality of medication-related osteonecrosis of the jaw (MRONJ) after tooth extraction under bisphosphonate (BF) therapy to identify knowledge gaps and guide future research.

DATA

This review used the PCC strategy (P = Patient; C = Concept; C = Context).

SOURCES

The MEDLINE/PubMed, Scopus, Web of Science/Clarivate Analytics, and gray literature databases were used.

STUDY SELECTION

Searches were conducted by two independent reviewers until April 2024. Studies involving prior BF use and tooth extraction in humans or animals were included. Among the 176 studies, 73 (41.4 %) were in animals, and 103 (58.5 %) were in humans. Brazil led in animal studies (n = 14; 19.1 %), while Italy led in human studies (n = 14; 13.6 %). Zoledronic acid was the most cited BF (79.4 % in animals; 34.9 % in humans), with intravenous administration being most frequent (38.3 % in animals; 35.9 % in humans). The mandible was the main extraction site (n = 36 in animals; n = 41 in humans). In 91.7 % of the animal studies, sequelae compatible with osteonecrosis signs and symptoms were observed, with bone necrosis being most common (n = 39; 53.4 %). In humans, 93.2 % of studies presented 239 sequelae, with bone necrosis (n = 53; 22.1 %) being the most cited. The main location of sequelae was the mandible (n = 36 in animals; n = 41 in humans).

CONCLUSIONS

Animal studies highlighted bone exposure, notably using murine models, with a significant Brazilian contribution. In human studies, bone necrosis was the main sequela of MRONJ, which has been reported by researchers in the Italy.

CLINICAL SIGNIFICANCE

These findings underscore the importance of careful consideration and monitoring of patients who have a history of bisphosphonate use and who are undergoing tooth extraction, highlighting the potential risk of MRONJ.

The Role of Cone Beam Computed Tomography (CBCT) in the Diagnosis and Clinical Management of Medication-Related Osteonecrosis of the Jaw (MRONJ)

Medication-related osteonecrosis of the jaw (MRONJ) is a debilitating condition associated with antiresorptive and antiangiogenic medications that are frequently used in treating osteoporosis and cancers. With the ability to produce high-resolution images with a lower radiation dose, cone beam computed tomography (CBCT) is an emerging technology in maxillofacial imaging that offers several advantages in evaluating MRONJ. This review aims to summarise the radiological features of MRONJ as observed via CBCT and highlight its advantages over two-dimensional plain films in assessing MRONJ. CBCT has the capability to detect early MRONJ lesions, characterise the extent and nature of lesions, distinguish MRONJ from other osseous pathologies, and assist in treatment planning. By leveraging the advantages of CBCT, clinicians can enhance their understanding of MRONJ, improve decision making, and ultimately optimize patient care.

Does the use of bisphosphonates during pregnancy affect fetal outcomes? A systematic review

PURPOSE

This systematic review aimed to determine the effects of maternal exposure to bisphosphonates (BPs) during pregnancy on neonatal outcomes. It aimed to disclosfe the impact of BPs on neonates and identify aspects that require further investigation.

METHODS

A comprehensive search of PubMed, Science Direct, LILACS, EMBASE, and Web of Science was conducted until August 2022, with no time restrictions. The selection criteria included studies published in English that evaluated pregnant women who were exposed to BPs.

RESULTS

From an initial pool of 2169 studies, 13 met the inclusion criteria for this systematic review. These studies collectively included 106 women (108 pregnancies) who were exposed to BPs either before orduring pregnancy. A summary of the key characteristics of the selected studies and the risk of bias assessment are provided. Exposure to BPs occurs at various stages of pregnancy, with different indications for BP treatment. The most frequently reported neonatal outcomes were spontaneous abortion, congenital malformations, hypocalcemia, preterm birth, and low birth weight.

CONCLUSION

Although previous reports have linked BPs before or during pregnancy with adverse neonatal outcomes, these associations should be interpreted with caution. Given the complexity of these findings, further research is necessary to provide more definitive insights to guide clinical decisions regarding the use of BPs in pregnant women.

Potential Targeting Mechanisms for Bone-Directed Therapies

Bone development is characterized by complex regulation mechanisms, including signal transduction and transcription factor-related pathways, glycobiological processes, cellular interactions, transportation mechanisms, and, importantly, chemical formation resulting from hydroxyapatite. Any abnormal regulation in the bone development processes causes skeletal system-related problems. To some extent, the avascularity of cartilage and bone makes drug delivery more challenging than that of soft tissues. Recent studies have implemented many novel bone-targeting approaches to overcome drawbacks. However, none of these strategies fully corrects skeletal dysfunction, particularly in growth plate-related ones. Although direct recombinant enzymes (e.g., Vimizim for Morquio, Cerezyme for Gaucher, Elaprase for Hunter, Mepsevii for Sly diseases) or hormone infusions (estrogen for osteoporosis and osteoarthritis), traditional gene delivery (e.g., direct infusion of viral or non-viral vectors with no modifications on capsid, envelope, or nanoparticles), and cell therapy strategies (healthy bone marrow or hematopoietic stem cell transplantation) partially improve bone lesions, novel delivery methods must be addressed regarding target specificity, less immunogenicity, and duration in circulation. In addition to improvements in bone delivery, potential regulation of bone development mechanisms involving receptor-regulated pathways has also been utilized. Targeted drug delivery using organic and inorganic compounds is a promising approach in mostly preclinical settings and future clinical translation. This review comprehensively summarizes the current bone-targeting strategies based on bone structure and remodeling concepts while emphasizing potential approaches for future bone-targeting systems.

Clinical challenges and considerations in pharmacotherapy of osteoporosis due to menopause

INTRODUCTION

Osteoporosis is a chronic systemic skeletal disorder characterized by compromised bone strength and an increased risk of fracture, with a high prevalence worldwide. It is associated with a negative quality of life and an increased morbidity and mortality. Postmenopausal women are more prone to develop osteoporosis, and many of them will suffer at least one fragility fracture along their lifetime.

AREAS COVERED

This review starts by summarizing the pathogenesis of postmenopausal osteoporosis (PMO), with focus on the estrogen deficiency-associated bone loss. It continues with the current PMO diagnostic and fracture risk prediction tools, and it finally addresses management of PMO. All the efficacy and safety profiles of the current and future osteoporosis medications are reviewed. Furthermore, strategies to optimize the long-term disease management are discussed. For this review, only publications in English language were selected. References were extracted from PubMed, Embase, and Medline.

EXPERT OPINION

PMO disease management is far from being ideal. Educational and communication programs with the goal of improving disease knowledge and awareness, as well as reducing the health-care gap, should be implemented. In addition, most effective sequential prevention and treatment strategies should be initiated from the early menopause.

Initiation of Bisphosphonates Prior to Total Joint Arthroplasty Does Not Lower Periprosthetic Fracture Risk

BACKGROUND

Many patients are diagnosed with osteoporosis shortly prior to scheduling total joint arthroplasty (TJA). The purpose of this study was to determine if initiation of bisphosphonates prior to TJA decreased the risks of periprosthetic fractures (PPFx).

METHODS

A national database was used to identify all patients diagnosed with osteoporosis prior to primary TJA. Patients who had osteoporosis without preoperative bisphosphonate use were designated as our control group. Patients on preoperative bisphosphonates were stratified based on duration and timing of bisphosphonate use: long-term preoperative users (initiation 3 to 5 years preoperatively), intermediate-term preoperative users (initiation 1 to 3 years preoperatively), and short-term preoperative users (initiation 0 to 1 year preoperatively). Rates of PPFx at 90-day and 2-year follow-up were compared between groups.

RESULTS

In patients undergoing primary total hip arthroplasty, there was no difference in PPFx rate between our control group and preoperative bisphosphonate users of all durations at 90-day (P = .12) and 2-year follow-up (P = .22). In patients undergoing primary total knee arthroplasty, there was no difference in PPFx rate between our control group and preoperative bisphosphonate users of all durations at 90-day (P = .76) and 2-year follow-up (P = .39).

CONCLUSIONS

In patients undergoing primary TJA, preoperative bisphosphonate users did not have a decreased PPFx rate compared to our control group at 90-day and 2-year follow-up. Our findings suggest that preoperative bisphosphonate use, regardless of the duration of treatment, does not confer protective benefits against PPFx in patients undergoing TJA.

LEVEL OF EVIDENCE

Prognostic Level III.

Cholesterol nanoarchaeosomes for alendronate targeted delivery as an anti-endothelial dysfunction agent

Sodium alendronate (ALN) is a very hydrosoluble and poorly permeable molecule used as an antiresorptive agent and with vascular anticalcifying capacity. Loaded into targeted nanovesicles, its anti-inflammatory activity may be amplified towards extra-osseous and noncalcified target cells, such as severely irritated vascular endothelium. Here cytotoxicity, mitochondrial membrane potential, ATP content, and membrane fluidity of human endothelial venous cells (HUVECs) were determined after endocytosis of ALN-loaded nanoarchaeosomes (nanoARC-Chol(ALN), made of polar lipids from Halorubrum tebenquichense: cholesterol 7:3 w/w, 166 ± 5 nm, 0.16 ± 0.02 PDI, -40.8 ± 5.4 mV potential, 84.7 ± 21 µg/mg ALN/total lipids, TL). The effect of nanoARC-Chol(ALN) was further assessed on severely inflamed HUVECs. To that aim, HUVECs were grown on a porous barrier on top of a basal compartment seeded either with macrophages or human foam cells. One lighter and one more pronounced inflammatory context was modelled by adding lipopolysaccharide (LPS) to the apical or the apical and basal compartments. The endocytosis of nanoARC-Chol(ALN), was observed to partly reduce the endothelial-mesenchymal transition of HUVECs. Besides, while 10 mg/mL dexamethasone, 7.6 mM free ALN and ALN-loaded liposomes failed, 50 μg/mL TL + 2.5 μg/mL ALN (i.e., nanoARC-Chol(ALN)) reduced the IL-6 and IL-8 levels by, respectively, 75% and 65% in the mild and by, respectively, 60% and 40% in the pronounced inflammation model. This is the first report showing that the endocytosis of nanoARC-Chol(ALN) by HUVECs magnifies the anti-inflammatory activity of ALN even under conditions of intense irritation, not only surpassing that of free ALN but also that of dexamethasone.

The interplay of rheumatoid arthritis and osteoporosis: exploring the pathogenesis and pharmacological approaches

Rheumatoid arthritis (RA) and osteoporosis are two chronic disorders that are often seen together. RA is an autoimmune disorder that causes pain and inflammation in the joints, while osteoporosis is a disorder in which the bones become weak and fragile. Risk factors for bone loss in RA include disease activity, longer disease duration, erosive disease, autoantibody positivity, and joint damage leading to impaired physical activity. Recent research has shown that there is a complex interplay between immune cells, cytokines, and bone remodeling processes in both RA and osteoporosis. The bone remodeling process is regulated by cytokines and immune system signaling pathways, with osteoclasts activated through the RANK/RANKL/OPG pathway and the Wnt/DKK1/sclerostin pathway. Understanding these mechanisms can aid in developing targeted therapies for treatment of osteoporosis in RA patients. Current pharmacological approaches include anti-osteoporotic drugs such as bisphosphonates, denosumab, teriparatide, abaloparatide, raloxifene, and romosozumab. Conventional disease-modifying antirheumatic drugs such as methotrexate and biologicals including TNF inhibitors, IL-6 inhibitors, rituximab, and abatacept lower disease activity in RA and can improve bone metabolism by reducing inflammation but have limited impact on bone mineral density. This review will shed light on the relationship between osteoporosis and rheumatoid arthritis as well as the various factors that influence the onset of osteoporosis in RA patients. We also explore several treatment approaches to effectively managing osteoporosis in RA patients.

Clodronate disodium does not produce measurable effects on bone metabolism in an exercising, juvenile, large animal model

Bisphosphonates are commonly used to treat and prevent bone loss, but their effects in active, juvenile populations are unknown. This study examined the effects of intramuscular clodronate disodium (CLO) on bone turnover, serum bone biomarkers (SBB), bone mineral density (BMD), bone microstructure, biomechanical testing (BT), and cartilage glycosaminoglycan content (GAG) over 165 days. Forty juvenile sheep (253 ± 6 days of age) were divided into four groups: Control (saline), T0 (0.6 mg/kg CLO on day 0), T84 (0.6 mg/kg CLO on day 84), and T0+84 (0.6 mg/kg CLO on days 0 and 84). Sheep were exercised 4 days/week and underwent physical and lameness examinations every 14 days. Blood samples were collected for SBB every 28 days. Microstructure and BMD were calculated from tuber coxae (TC) biopsies (days 84 and 165) and bone healing was assessed by examining the prior biopsy site. BT and GAG were evaluated postmortem. Data, except lameness data, were analyzed using a mixed-effects model; lameness data were analyzed as ordinal data using a cumulative logistic model. CLO did not have any measurable effects on the skeleton of sheep. SBB showed changes over time (p ≤ 0.03), with increases in bone formation and decreases in some bone resorption markers. TC biopsies showed increasing bone volume fraction, trabecular spacing and thickness, and reduced trabecular number on day 165 versus day 84 (p ≤ 0.04). These changes may be attributed to exercise or growth. The absence of a treatment effect may be explained by the lower CLO dose used in large animals compared to humans. Further research is needed to examine whether low doses of bisphosphonates may be used in active juvenile populations for analgesia without evidence of bone changes.

Sclerotic bone: a sign of bone reaction in patients with medication related osteonecrosis of the jaw

Medication-related osteonecrosis of the jaw (MRONJ) is a serious adverse reaction associated with antiresorptive drugs such as bisphosphonates and denosumab. When dealing with advanced and/or multiple MRONJ lesions undergoing surgical therapy, the extent of surgery is often a topic of discussion. The aim of this study was to identify the differences in bone density in and around the MRONJ lesion before and after surgical treatment to evaluate the needed surgical extend of the modelling osteotomy. In this retrospective study 26 patients with MRONJ lesions that were surgically treated in our department were observed. Length, width and bone density were measured in panoramic radiograph pre and postoperatively with the Imaging processing software Sidexis and ImageJ (Fiji). The necrotic area, the surrounding sclerotic area as well as the healthy contralateral side were observed. Measurements were performed by two independent observers. Pearson correlation was calculated to determine the interobserver variability. Bone density was significantly reduced in the necrotic bone area compared to the healthy unaffected contralateral reference side. The sclerotic bone area surrounding the necrosis showed increased bone density compared to the contralateral unaffected reference side. The density of the sclerotic bone area was increased in the previously affected MRONJ area in the postoperative panoramic radiograph. The pre and postoperative density showed no significant correlation to healing behaviour. The focus of the modelling osteotomy in surgical treatment of mature MRONJ lesions should be predominantly on the parts that appear necrotic and less dense in the panoramic radiograph as sclerotic areas might be an expression of bone reaction.

The novel cytotoxic polybisphosphonate osteodex decreases bone resorption by enhancing cell death of mature osteoclasts without affecting osteoclastogenesis of RANKL-stimulated mouse bone marrow macrophages

It has previously been demonstrated that the polybisphosphonate osteodex (ODX) inhibits bone resorption in organ-cultured mouse calvarial bone. In this study, we further investigate the effects by ODX on osteoclast differentiation, formation, and function in several different bone organ and cell cultures. Zoledronic acid (ZOL) was used for comparison. In retinoid-stimulated mouse calvarial organ cultures, ODX and ZOL significantly reduced the numbers of periosteal osteoclasts without affecting Tnfsf11 or Tnfrsf11b mRNA expression. ODX and ZOL also drastically reduced the numbers of osteoclasts in cell cultures isolated from the calvarial bone and in vitamin D3-stimulated mouse crude bone marrow cell cultures. These data suggest that ODX can inhibit osteoclast formation by inhibiting the differentiation of osteoclast progenitor cells or by directly targeting mature osteoclasts. We therefore assessed if osteoclast formation in purified bone marrow macrophage cultures stimulated by RANKL was inhibited by ODX and ZOL and found that the initial formation of mature osteoclasts was not affected, but that the bisphosphonates enhanced cell death of mature osteoclasts. In agreement with these findings, ODX and ZOL did not affect the mRNA expression of the osteoclastic genes Acp5 and Ctsk and the osteoclastogenic transcription factor Nfatc1. When bone marrow macrophages were incubated on bone slices, ODX and ZOL inhibited RANKL-stimulated bone resorption. In conclusion, ODX does not inhibit osteoclast formation but inhibits osteoclastic bone resorption by decreasing osteoclast numbers through enhanced cell death of mature osteoclasts.

Theranostic Agent Targeting Bone Metastasis: A Novel [68Ga]Ga/[177Lu]Lu-DOTA-HBED-bisphosphonate

Bone metastasis in cancer patients is a major disease advancement for various types of cancer. Previously, [68Ga]Ga-HBED-CC-bisphosphonate ([68Ga]Ga-P15-041) showed excellent bone uptake and efficient detection of bone metastasis in patients. To accommodate different α- or β--emitting metals for radionuclide therapy, a novel DOTA-HBED-CC-bisphosphonate (P15-073, 1) was prepared and the corresponding [68Ga]Ga-1 and [177Lu]Lu-1 were successfully synthesized in high yields and purity. Gallium-68 conjugation to HBED-CC at room temperature and lutetium-177 conjugation to DOTA at 95 °C were verified in model compounds through secondary mass confirmation. These bisphosphonates, [68Ga]Ga-1 and [177Lu]Lu-1, displayed high binding affinity to hydroxyapatite in vitro. After an iv injection, it showed excellent uptake in the spine of normal mice, and micro-PET/CT imaging of nude mice model of bone metastasis showed high bone uptake in tumor tissue. The results indicated that [68Ga]Ga/[177Lu]Lu-1 holds promise as a theranostic radioligand agent for managing cancer bone metastases.

Efficacy of Osteoporosis Medications in Patients with Type 2 Diabetes

PURPOSE OF THE REVIEW

The purpose of the review is to summarise the current scientific evidence on the efficacy of osteoporosis medications in patients with type 2 diabetes.

RECENT FINDINGS

Type 2 diabetes (T2D) is a growing global epidemic. The highest prevalence is observed in the elderly, the same population affected by osteoporosis. Despite normal or even increased bone mineral density and low bone turnover, T2D is associated with an increased risk of fractures in most skeletal sites. These findings raised concerns over the efficacy of anti-osteoporosis drugs in this population. There is no randomised controlled trial designed specifically for people with T2D. However, observational studies and post-hoc analyses of randomised controlled trials have provided valuable insights into the effects of various anti-osteoporosis treatments in this population. Overall, most anti-osteoporosis drugs seem to have similar efficacy and safety profiles for people with and without type 2 diabetes. However, continued research and long-term safety data are needed to optimise treatment strategies and improve bone health outcomes in this population. The current evidence suggests that most anti-osteoporosis drugs exhibit comparable efficacy in people with and without T2D.

Unexpected chronic lymphocytic leukemia B cell activation by bisphosphonates

Chronic lymphocytic leukemia (CLL) is a disease of the elderly, often presenting comorbidities like osteoporosis and requiring, in a relevant proportion of cases, treatment with bisphosphonates (BPs). This class of drugs was shown in preclinical investigations to also possess anticancer properties. We started an in vitro study of the effects of BPs on CLL B cells activated by microenvironment-mimicking stimuli and observed that, depending on drug concentration, hormetic effects were induced on the leukemic cells. Higher doses induced cytotoxicity whereas at lower concentrations, more likely occurring in vivo, the drugs generated a protective effect from spontaneous and chemotherapy-induced apoptosis, and augmented CLL B cell activation/proliferation. This CLL-activation effect promoted by the BPs was associated with markers of poor CLL prognosis and required the presence of bystander stromal cells. Functional experiments suggested that this phenomenon involves the release of soluble factors and is increased by cellular contact between stroma and CLL B cells. Since CLL patients often present comorbidities such as osteoporosis and considering the diverse outcomes in both CLL disease progression and CLL response to treatment among patients, illustrating this phenomenon holds potential significance in driving additional investigations.

Plant-derived natural medicines for the management of osteoporosis: A comprehensive review of clinical trials

Background

Osteoporosis is a chronic and systemic skeletal disease that is defined by low bone mineral density (BMD) along with an increase in bone fragility and susceptibility to fracture. This study aimed to overview clinical evidence on the use of herbal medicine for management of osteoporosis.

Methods

Electronic databases including Pubmed, Medline, Cochrane library, and Scopus were searched until November 2022 for any clinical studies on the efficacy and/or safety of plant-derived medicines in the management of osteoporosis.

Results

The search yielded 57 results: 19 on single herbs, 16 on multi-component herbal preparations, and 22 on plant-derived secondary metabolites. Risk of fracture, bone alkaline phosphatase, BMD, and specific bone biomarkers are investigated outcomes in these studies. Medicinal plants including Acanthopanax senticosus, Actaea racemosa, Allium cepa, Asparagus racemosus, Camellia sinensis, Cissus quadrangularis, Cornus mas, Nigella sativa, Olea europaea, Opuntia ficus-indica, Pinus pinaster, Trifolium pretense and phytochemicals including isoflavones, ginsenoside, Epimedium prenyl flavonoids, tocotrienols are among plant-derived medicines clinically investigated on osteoporosis. It seems that multi-component herbal preparations were more effective than single-component ones; because of the synergistic effects of their constituents. The investigated herbal medicines demonstrated their promising results in osteoporosis via targeting different pathways in bone metabolism, including balancing osteoblasts and osteoclasts, anti-inflammatory, immunomodulatory, antioxidant, and estrogen-like functions.

Conclusion

It seems that plant-derived medicines have beneficial effects on bone and may manage osteoporosis by affecting different targets and pathways involved in osteoporosis; However, Future studies are needed to confirm the effectiveness and safety of these preparations.

Osteoporosis treatment and pain relief: A scoping review

BACKGROUND AND OBJECTIVE

Anti-osteoporosis (OP) drugs have been suggested to contribute to pain reduction during OP management. This scoping review aimed at mapping the literature on pain relief with anti-OP drugs in OP treatment.

DATABASES AND DATA TREATMENT

Medline, Pubmed and Cochrane databases were searched by two reviewers with keywords combinations. Randomized controlled and real-life English studies, pain as an endpoint, antiosteoporosis drugs were inclusion criteria. Case reports, surveys, comment letters, conference abstracts, animal studies and grey literature were excluded. Predetermined data were extracted by two reviewers and disagreement solved through discussion.

RESULTS

A total of 130 articles were identified, 31 publications were included, 12 randomized clinical trials and 19 observational studies. Pain reduction was assessed by different tools: Visual Analogue Scale, Verbal Rating Scale, Facial Scale or as a domain of quality of life questionnaires including Short form 8, 36, mini-OP, Japanese OP, Qualeffo, Roland Morris Disability questionnaires. Collective data show that anti-OP drugs may display an analgesic effect that may be linked to the local mode of action of drugs on bone and consecutive modulation of pain sensitization. The methodology of the studies showed a heterogeneity of endpoints, comparators, statistical approaches and follow-up duration.

CONCLUSION

Considering the limitations of the literature, there is a need for more rigorous trials and larger real-life studies taking into account the recommendations published for research in rheumatology and in pain medicine. The identification of responders, patient subtypes, and of analgesic-effect doses would allow optimization and individualization for pain relief in patients with OP.

SIGNIFICANCE STATEMENT

This scoping review shows that anti-OP drugs may improve pain and quality of life of patients with OP. The heterogeneity in design, choice of endpoints, methodology, comparators and follow-up duration of included randomized clinical trials and real-life studies does not allow so far to identify a predominant antiosteoporosis drug or an optimal dosage for pain relief. These gaps need to be addressed and warrant further research in the future for optimizing pain improvement in the course of OP drug treatment.

Role of Actinomyces spp. and related organisms in the development of medication-related osteonecrosis of the jaw (MRONJ): Clinical evidence based on a case series

Medication-related osteonecrosis of the jaw (MRONJ) is an increasingly common consequence of antiresorptive treatment, which often leads to the development of necrotic exposed bone surfaces with inflammatory processes affecting the jawbone. Although the development of MRONJ is often associated with the inflammatory response or infections caused by the colonizing members of the oral microbiota, the exact pathogenesis of MRONJ is still not fully understood. In the present paper, we aimed to provide additional, microbiological culture-supported evidence, supporting the "infection hypothesis" that Actinomyces spp. and related organisms may play an important pathogenic role in the development of MRONJ and the resulting bone necrosis. In our case series, all patients presented with similar underlying conditions and anamnestic data, and have received antiresorptive medications (bisphosphonates or a RANK ligand (RANKL) inhibitor) to prevent the occurrence or progression of bone metastases, secondary to prostate cancer. Nevertheless, a few years into antiresorptive drug therapy, varying stages of MRONJ was identified in the mentioned patients. In all three cases, quantitative microbiological culture of the necrotic bone samples yielded a complex microbiota, dominated by Actinomyces and Schaalia spp. with high colony counts. Additionally, our followed-up case series document the treatment of these patients with a combination of surgical intervention and long-term antibiotic therapy, where favourable clinical responses were seen is all cases. If the "infection hypothesis" is valid, it may have significant consequences in the preventative and therapeutic strategies associated with this disease.

Theoretical insights and implications of pH-dependent drug delivery systems using silica and carbon nanotube

In this paper we have studied the density functional theory of four drugs ibuprofen, alendronate, Sulfasalazine and paracetamol with quartz, propylamine, trimethylamine functionalized quartz and carboxyl modified carbon nanotube. The attractive and repulsive interaction energies between drugs and quartz is obtained at various pH values. The attractive and repulsive energies are well correlated with experimental drug loading and releasing behavior by mesoporous silica nanoparticles. Further, a theoretical model is developed that accounts the electrostatic interaction between silica and drug and the model can predict the drug loading and releasing behavior by silica nanoparticles at various pH values. Sulfasalazine can be taken orally and loaded with trimethyl ammonium functionalized mesoporous silica nanoparticles, which keeps the drug in tact with the carrier in the acidic environment of the stomach and releases it into the neutral or basic medium of the small intestine. Alendronate may be loaded and released from propylamine functionalized mesoporous silica nanoparticles in the ranges of 1-5 and > 8, respectively. Ibuprofen is absorbed in an acidic environment and released in basic conditions for carboxyl modified carbon nanotube. The loading and releasing pH ranges for paracetamol in trimethylammonium functionalized mesoporous silica nanoparticles are 4-8 and >8, respectively. We also convert the pH-dependent variant of the diffusion-controlled Higuchi equation. We have changed the original Higuchi equation to produce the pH-dependent variation by incorporating the Nernst-Planck equation into Flick's first law. The updated equation could be used to forecast when medication particles with varying release times will emerge from a nanoparticles matrix.

Potential application of anti-osteoporotic therapy to relieve sarcopenia in the elderly

Sarcopenia is a progressive and systemic skeletal muscle disorder associated with aging that usually occurs with age in the elderly. Sarcopenia currently lacks effective pharmacological treatment modalities. Multiple pharmacological intervention modalities are available for osteoporosis, a comprehensive disease characterized by decreased systemic bone mass, degradation of bone microarchitecture, and increased bone fragility. Several recent studies have shown an extremely strong correlation between sarcopenia and osteoporosis, leading to the concept of "osteosarcopenia". Therefore, it is possible to alleviate sarcopenia simultaneously by improving osteoporosis.

Electrocardiogram Changes Following Intravenous Bisphosphonate Infusion: A Systematic Review and Meta-Analysis

Bisphosphonates are first-line treatments for several bone and mineral disorders. Studies have reported an increased incidence of serious atrial fibrillation in patients receiving bisphosphonates; however, uncertainty remains as to whether electrical disturbances are precipitated by bisphosphonates. We aimed to review the literature for studies reporting electrocardiogram (ECG) findings in patients receiving intravenous bisphosphonates for any indication. We searched MEDLINE and EMBASE from inception until January 14, 2023, for studies reporting ECG parameters after intravenous bisphosphonate infusion. We excluded studies that only reported atrial fibrillation. Study quality was assessed using the Newcastle-Ottawa scale. Continuous data were meta-analyzed if reported in at least two studies. Random-effects models were fitted and reported as standardized mean difference (SMD) with 95% confidence intervals (95% CIs). We found 1083 unique records, of which 11 met our inclusion and exclusion criteria. Studies had a low to low/moderate risk of bias. Six prospective cohort studies were included in the meta-analysis. Five studies used zoledronic acid, whereas one study used pamidronate. Most studies (n = 4) were conducted in postmenopausal women with osteoporosis, one study was conducted in patients with bone metastases, and one study in children with osteoporosis secondary to cerebral palsy. Study populations ranged from n = 15 to n = 116. Heart rate-corrected QT (QTc) was significantly longer post-infusion (SMD = 0.46 ms [95% CI 0.80 to 0.11]; n = 67 patients, k = 2 studies, τ2  = 0). There were no differences in heart rate, P wave (maximum), P wave (minimum), P wave dispersion, PR interval, QRS duration, QTc, QTc (maximum), QTc (minimum), and QTc dispersion. The correlation between pre- and post-infusion QTc was not significant (p = 0.93). Overall, there is a weak association between intravenous bisphosphonate infusion and a QTc interval prolongation. However, there is insufficient evidence to support an association between intravenous bisphosphonate and any ECG variable changes, which may precipitate atrial fibrillation. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Bisphosphonates and osteonecrosis of the jaws: Clinical and forensic aspects

OBJECTIVE

This manuscript aims to provide a comprehensive review of the current knowledge in the pathophysiology, diagnosis, prevention, and other relevant clinical and forensic aspects of a potentially severe complication known as medication-related osteonecrosis of the jaw (MRONJ) while synthesizing state-of-the-art information on bisphosphonates and introducing a possible differential diagnosis.

DESIGN

An extensive search was conducted in PubMed (U.S. National Library of Medicine) without a time or language constraint, focusing on the epidemiology, pathophysiology, risk factors, site specificity, signs and symptoms, differential diagnosis, prevention, and forensic aspects of MRONJ. All types of original articles, reviews, case reports, short communications, opinion articles, guidelines, and letters to editors were considered to produce a complete review on this subject.

RESULTS

MRONJ prevention relies on a multidisciplinary approach and is critical since truly effective treatments are lacking. This therapeutic challenge is partly due to uncertainty regarding this condition's pathophysiology. Differential diagnosis of osteonecrosis of the jaws associated with krokodil abuse, one of the most dangerous and homemade psychoactive illicit substances, should be considered.

CONCLUSIONS

Further research into the etiology and site specificity of MRONJ is encouraged, aiming to develop novel treatment prospects. Indeed, comprehending this would allow for increased efficacy and therapeutic options while emphasizing the importance of prevention. In addition, we advocate for greater consensus among the various societies regarding MRONJ's treatment and management.

Association Between CTSK Gene Polymorphisms and Response to Alendronate Treatment in Postmenopausal Chinese Women with Low Bone Mineral Density

Purpose

The aim of this study was to explore the association between CTSK polymorphisms and the response to alendronate treatment in postmenopausal Chinese women with low bone mineral density.

Patients and Methods

In this study, 460 postmenopausal women from Shanghai were included. All of them were treated with weekly oral alendronate 70 mg, daily calcium 600 mg and vitamin D 125 IU for a year. Four tag single nucleotide polymorphisms (SNPs) in CTSK gene were genotyped. Bone mineral densities of lumbar spine (L1-L4), femoral neck and total hip were measured at baseline and after 12 months of treatment, respectively.

Results

After 1-year of treatment, there was no significant differences in BMI between baseline and follow-up. After alendronate treatment, the BMD of L1-4, femoral neck and total hip all increased significantly (all P < 0.001), with average increases of 4.33 ± 6.42%, 1.85 ± 4.20%, and 2.36 ± 3.79%, respectively. There was no significant difference in BMD at L1-L4, the femoral neck and total hip between different genotype groups at baseline (P>0.05). After 1-year treatment with alendronate, rs12746973 and rs10847 were associated with the % change of BMD at L1-L4 (P=0.038) and % change of BMD at femoral neck (P=0.038), respectively. Furthermore, rs10847 was associated with BMD response at femoral neck (P=0.013). However, the associations were not significant after Bonferroni correction.

Conclusion

We concluded that the common variations of CTSK gene were potentially associated with the therapeutic response to alendronate treatment in Chinese women with low bone mineral density. However, further validation is needed.

Evidence of bisphosphonate-conjugated sitafloxacin eradication of established methicillin-resistant S. aureus infection with osseointegration in murine models of implant-associated osteomyelitis

Eradication of MRSA osteomyelitis requires elimination of distinct biofilms. To overcome this, we developed bisphosphonate-conjugated sitafloxacin (BCS, BV600072) and hydroxybisphosphonate-conjugate sitafloxacin (HBCS, BV63072), which achieve "target-and-release" drug delivery proximal to the bone infection and have prophylactic efficacy against MRSA static biofilm in vitro and in vivo. Here we evaluated their therapeutic efficacy in a murine 1-stage exchange femoral plate model with bioluminescent MRSA (USA300LAC::lux). Osteomyelitis was confirmed by CFU on the explants and longitudinal bioluminescent imaging (BLI) after debridement and implant exchange surgery on day 7, and mice were randomized into seven groups: 1) Baseline (harvested at day 7, no treatment); 2) HPBP (bisphosphonate control for BCS) + vancomycin; 3) HPHBP (hydroxybisphosphonate control for HBCS) + vancomycin; 4) vancomycin; 5) sitafloxacin; 6) BCS + vancomycin; and 7) HBCS + vancomycin. BLI confirmed infection persisted in all groups except for mice treated with BCS or HBCS + vancomycin. Radiology revealed catastrophic femur fractures in all groups except mice treated with BCS or HBCS + vancomycin, which also displayed decreases in peri-implant bone loss, osteoclast numbers, and biofilm. To confirm this, we assessed the efficacy of vancomycin, sitafloxacin, and HBCS monotherapy in a transtibial implant model. The results showed complete lack of vancomycin efficacy while all mice treated with HBCS had evidence of infection control, and some had evidence of osseous integrated septic implants, suggestive of biofilm eradication. Taken together these studies demonstrate that HBCS adjuvant with standard of care debridement and vancomycin therapy has the potential to eradicate MRSA osteomyelitis.

Osteoimmunology of Spondyloarthritis

The mechanisms underlying the development of bone damage in the context of spondyloarthritis (SpA) are not completely understood. To date, a considerable amount of evidence indicates that several developmental pathways are crucially involved in osteoimmunology. The present review explores the biological mechanisms underlying the relationship between inflammatory dysregulation, structural progression, and osteoporosis in this diverse family of conditions. We summarize the current knowledge of bone biology and balance and the foundations of bone regulation, including bone morphogenetic protein, the Wnt pathway, and Hedgehog signaling, as well as the role of cytokines in the development of bone damage in SpA. Other areas surveyed include the pathobiology of bone damage and systemic bone loss (osteoporosis) in SpA and the effects of pharmacological treatment on focal bone damage. Lastly, we present data relative to a survey of bone metabolic assessment in SpA from Italian bone specialist rheumatology centers. The results confirm that most of the attention to bone health is given to postmenopausal subjects and that the aspect of metabolic bone health may still be underrepresented. In our opinion, it may be the time for a call to action to increase the interest in and focus on the diagnosis and management of SpA.

Assessment Results of Dental Students' Knowledge about Bisphosphonates and Bisphosphonate-Related Osteonecrosis of the Jaw

Objectives

The aim of this cross-sectional study is to evaluate Lithuanian fourth- and fifth-year dental students' knowledge about bisphosphonates and bisphosphonate-related osteonecrosis of the jaw.

Material and Methods

The anonymous survey using a questionnaire was conducted from February to March 2022. The survey was sent to 173 students at Lithuanian University of Health Sciences (LSMU) and 107 of them were completed. It consisted of student data, questions about the main properties of bisphosphonates, bisphosphonate-related osteonecrosis of the jaw (BRONJ), and the necessity of additional studies for students. Chi-square test and Cramér's V coefficient were used for the analysis of variables.

Results

Most of the fifth-year students knew the main properties of bisphosphonates and what diseases they are used to treat. Twenty fifth-year students (33.9%) knew the accurate definition of BRONJ, while only 11 fourth-year students (22.9%) chose the same correct answer. Statistically significant (P < 0.05) data were found about the knowledge of main properties of bisphosphonates. The vast majority of fourth- and fifth-year students (39 [81.3%] and 45 [76.3%]), agreed that the University should provide more information about bisphosphonates.

Conclusions

The study revealed that fifth-year students demonstrated better knowledge about bisphosphonates compared to fourth-year students and this was due to a curriculum supplemented with information about this pathology. The overall findings of this research suggest that Universities need to expand their student curricula by providing more knowledge about bisphosphonates and its relation to bisphosphonate-related osteonecrosis of the jaw.

Comparison of the Effectiveness of Conservative and Surgical Treatment of Medication-Related Osteonecrosis of the Jaw: a Systematic Review

Objectives

The objective of this systematic review is to evaluate the current knowledge on the effectiveness of conservative and surgical treatment of medication-related osteonecrosis of the jaw.

Material and Methods

MEDLINE (PubMed), ScienceDirect and Cochrane Library search in combination with hand-search of relevant journals was conducted including human studies published in English between January 2017 and February 2023. Studies assessing treatment strategies for medication-related osteonecrosis of the jaw (MRONJ) were included. Quality and risk-of-bias assessment were evaluated by Joanna Briggs Institute (JBI) Risk of Bias tool.

Results

A total of 4227 articles were screened from which 9 studies (7 cohort studies and 2 randomized controlled trials) met the inclusion criteria and were included in the final data synthesis. Two studies evaluate effectiveness of conservative approaches for treating MRONJ, 5 studies evaluate surgical approaches effectiveness, and 2 studies compare between those approaches. The follow-up period ranged from 6 months to 60 months. According to bias assessment, the mean JDI score of the included studies was > 9 ("low risk of bias"). The stage of the disease, the procedure performed on the patient and the results of the treatment were presented.

Conclusions

Surgical therapy seems to be superior to conservative therapy for the management of adverse stages medication-related osteonecrosis of the jaws, while conservative treatment appears to yield good outcomes at asymptomatic patients with early stages of the disease.

The Capacity of Magnesium to Induce Osteoclast Differentiation Is Greatly Enhanced by the Presence of Zoledronate

Bisphosphonates (BPs) are successfully used to cure a number of diseases characterized by a metabolic reduction in bone density, such as Osteoporosis, or a neoplastic destruction of bone tissue, such as multiple myeloma and bone metastases. These drugs exert their therapeutic effect by causing a systemic osteoclast depletion that, in turn, is responsible for reduced bone resorption. Unfortunately, in addition to their beneficial activity, BPs can also determine a frightening side effect known as osteonecrosis of the jaw (ONJ). It is generally believed that the inability of osteoclasts to dispose of inflamed/necrotic bone represents the main physiopathological aspect of ONJ. In principle, a therapeutic strategy able to elicit a local re-activation of osteoclast production could counteract ONJ and promote the healing of its lesions. Using an experimental model of Vitamin D3-dependent osteoclastogenesis, we have previously demonstrated that Magnesium is a powerful inducer of osteoclast differentiation. Here we show that, surprisingly, this effect is greatly enhanced by the presence of Zoledronate, chosen for our study because it is the most effective and dangerous of the BPs. This finding allows us to hypothesize that Magnesium might play an important role in the topical therapy of ONJ.

Drug Delivery and Therapy Strategies for Osteoporosis Intervention

With the advent of the aging society, osteoporosis (OP) risk increases yearly. Currently, the clinical usage of anti-OP drugs is challenged by recurrent side effects and poor patient compliance, regardless of oral, intravenous, or subcutaneous administration. Properly using a drug delivery system or formulation strategy can achieve targeted drug delivery to the bone, diminish side effects, improve bioavailability, and prolong the in vivo residence time, thus effectively curing osteoporosis. This review expounds on the pathogenesis of OP and the clinical medicaments used for OP intervention, proposes the design approach for anti-OP drug delivery, emphatically discusses emerging novel anti-OP drug delivery systems, and enumerates anti-OP preparations under clinical investigation. Our findings may contribute to engineering anti-OP drug delivery and OP-targeting therapy.

Dental anomalies in individuals with osteogenesis imperfecta: a systematic review and meta-analysis of prevalence and comparative studies

BACKGROUND

Osteogenesis imperfecta (OI) is a rare genetic disorder primarily caused by mutations in the genes involved in the production of type 1 collagen. OI is also known as brittle bone disease.

OBJECTIVE

This study aims to describe the prevalence of dental anomalies (except dentinogenesis imperfecta) in individuals with OI, and compare the prevalence of dental anomalies between individuals with and without OI and between individuals with different types of OI.

SEARCH METHODS

Searches in PubMed, Web of Science, Scopus, Ovid, and gray literature were performed in October 2022.

SELECTION CRITERIA

Observational studies (with or without a comparison group) that evaluated the prevalence of dental anomalies in individuals with OI. Data collection and analysis: Data items were extracted by two authors. Quality assessment employing the Joanna Briggs Institute checklists and meta-analyses was conducted. Results were provided in prevalence values and odds ratio (OR) / 95% confidence interval (CI). Strength of evidence was determined.

RESULTS

Eighteen studies were included. Most prevalent dental anomalies in individuals with OI included pulp obliteration (46.4%), dental impaction (33.5%), dental impaction of second molars (27%), and tooth agenesis (23.9%). Individuals with OI type III/IV had 20.16-fold greater chance of exhibiting tooth discoloration in comparison with individuals with OI type I (CI: 1.10-370.98). In comparison with the group without OI, the individuals with OI had 6.90-fold greater chance of exhibiting dental impaction (CI: 1.54-31.00). High methodological quality was found in 47% of the studies. Strength of evidence was low or very low.

CONCLUSIONS

Pulp obliteration, dental impaction, and tooth agenesis were the most prevalent dental anomalies in the OI group. Individuals with OI were more likely to have dental impaction than individuals without OI. Individuals with OI type III/IV (severe-moderate) are more likely to have tooth discoloration than individuals with OI type I (mild).

Role of Cx43 on the Bone Cell Generation, Function, and Survival

The presence of gap junction intercellular communication structures in bone cells has been known since the early 1970s, further confirmed by Doty and Marotti at the structural level in the 1980-1990s. Work by Civitelli, Donahue, and others showed the expression of Cx43 at the mRNA and protein levels in all bone cell types: osteoclasts (bone resorbing cells), osteoblasts (bone forming cells), and osteocytes (mature osteoblasts embedded in the bone matrix that regulate the function of both osteoclasts and osteoblasts). While Cx45, Cx46, and Cx37 were also shown to be expressed in bone cells, most studies have focused on Cx43, the most abundant member of the connexin (Cx) family of proteins expressed in bone. The role of Cx43 has been shown to be related to the formation of gap junction intercellular channels, to unopposed hemichannels, and to channel independent functions of the molecule. Cx43 participates in the response of bone cells to pharmacological, hormonal, and mechanical stimuli, and it is involved in the skeletal phenotype with old age. Human and murine studies have shown that mutations of Cx43 lead to oculodentodigital dysplasia and craniometaphyseal dysplasia, both conditions associated with abnormalities in the skeleton. However, whereas substantial advances have been made on the skeletal role of Cx43, further research is needed to understand the basis for the effects of mutated Cx43 and potential ways to prevent the effects of these mutations on bone.

A Rare Case of Acute Calcium Pyrophosphate Deposition Disease Following Zoledronic Acid Infusion

Calcium pyrophosphate deposition (CPPD) disease of the joints is a form of arthritis that can present in a severely debilitating form of pseudogout. Although mostly idiopathic, pseudogout has been reported following bisphosphonate therapy in only nine cases to date with a pathophysiology that remains unclear. We present the case of a 59-year-old postmenopausal woman who developed the rare onset of acute polyarticular CPPD disease following zoledronic acid infusion for the treatment of osteoporosis.

Brown Tumour in Chronic Kidney Disease: Revisiting an Old Disease with a New Perspective

Osteitis fibrosa cystica (OFC) and Brown Tumours are two related but distinct types of bone lesions that result from the overactivity of osteoclasts and are most often associated with chronic kidney disease (CKD). Despite their potential consequences, these conditions are poorly understood because of their rare prevalence and variability in their clinical manifestation. Canonically, OFC and Brown Tumours are caused by secondary hyperparathyroidism in CKD. Recent literature showed that multiple factors, such as hyperactivation of the renin-angiotensin-aldosterone system and chronic inflammation, may also contribute to the occurrence of these diseases through osteoclast activation. Moreover, hotspot KRAS mutations were identified in these lesions, placing them in the spectrum of RAS-MAPK-driven neoplasms, which were until recently thought to be reactive lesions. Some risk factors contributed to the occurrence of OFC and Brown Tumours, such as age, gender, comorbidities, and certain medications. The diagnosis of OFC and Brown Tumours includes clinical symptoms involving chronic bone pain and laboratory findings of hyperparathyroidism. In radiological imaging, the X-ray and Computed tomography (CT) scan could show lytic or multi-lobular cystic alterations. Histologically, both lesions are characterized by clustered osteoclasts in a fibrotic hemorrhagic background. Based on the latest understanding of the mechanism of OFC, this review elaborates on the manifestation, diagnosis, and available therapies that can be leveraged to prevent the occurrence of OFC and Brown Tumours.