Search Results (136)

Background/Objectives: Bone-targeted drug delivery systems hold great promise for treating skeletal diseases, yet the optimal strategy for functionalizing lipid nanoparticles (LNPs) with bone-homing ligands remains insufficiently explored. Herein, we compared two alendronate sodium (Alen) modification approaches (pre-conjugation and post-conjugation) for constructing bone-targeted LNPs capable of delivering mRNA to skeletal tissues. Methods: LNPs were fabricated via microfluidic mixing, and the 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-polyethylene glycol-alendronate conjugate (DSPE-PEG-Alen) required for the pre-conjugation method was synthesized. The bone-targeting ability of LNPs prepared by the two Alen modification strategies was evaluated using an in vitro hydroxyapatite (HAP) binding assay. Furthermore, the physicochemical properties, bone-targeting performance, mRNA delivery efficiency, and biosafety of the LNPs prepared by the post-conjugation method were assessed through cellular uptake, in vivo imaging, and other methods. Results: Hydroxyapatite binding assays revealed that the post-conjugation strategy afforded significantly superior bone affinity compared to the pre-conjugation approach. In addition, ex vivo bone fragment binding experiments further confirmed that the bone-targeting LNPs prepared by the post-conjugation method exhibited stronger bone-binding capability compared to unmodified LNPs. The optimized Alen-LNPs demonstrated efficient cellular uptake and functional mRNA translation in bone marrow mesenchymal stem cells with negligible cytotoxicity. In vivo studies in mice confirmed the preferential accumulation of Alen-LNPs in bone tissues, with successful green fluorescent protein (GFP) mRNA translation detected in bone tissue sections. Histopathological analysis confirmed the biosafety of the formulation. Conclusions: This study establishes the post-conjugation strategy as the superior approach for Alen functionalization of LNPs, providing a robust and reproducible platform for bone-targeted mRNA therapeutics. Full article

Background/Objectives: The limited targeting efficiency and systemic toxicity of conventional medicine present significant challenges in the treatment of skeletal disorders, such as bone tuberculosis. To address these limitations, we developed a bone-targeting nanomicelle delivery system functionalized with alendronate (ALN), designated ALN-PLGA-mPEG@RPT, to improve the targeted delivery and therapeutic efficacy of rifapentine (RPT) in bone tissue. Methods: The ALN-PLGA-mPEG blank micelles, prepared in accordance with our research group’s optimized protocol, were loaded with RPT and subjected to systematic formulation optimization. The resulting nanomicellar system was comprehensively characterized in terms of its physicochemical properties, including particle size and polydispersity index (PDI). Additionally, drug-loading capacity, encapsulation efficiency, and in vitro release curve were evaluated. Bone-targeting efficacy was assessed using in vivo imaging techniques, while biodistribution and safety profiles were determined through in vivo distribution studies and histopathological examination. Results: The optimized ALN-PLGA-mPEG@RPT nanomicelles exhibited a mean particle size of 101.90 ± 4.17 nm, and a PDI of 0.242 ± 0.021. The formulation achieved a drug loading of 16.74 ± 0.51% with an encapsulation efficiency of 50.27 ± 1.91%. In vitro release studies confirmed a sustained-release profile, with only 25% of RPT released within 12 h. In vivo imaging revealed significantly enhanced bone-targeting capability in the ALN-modified group, showing a 1.93-fold higher drug accumulation in bone tissue compared to blood. Histopathological analysis indicated no observable pathological alterations in major organs. Conclusions: The ALN-PLGA-mPEG@RPT nanomicelle system exhibits favorable bone-targeting efficiency, sustained-release properties, and biocompatibility, representing a promising strategy for the precise treatment of bone tuberculosis and other skeletal diseases. Full article

Upconverting nanoparticles, which transform low-energy infrared radiation into high-energy visible or UV light, show great potential in today’s technology. High-quality upconversion colloid (UCC) consisting of lanthanide-based nanoparticles with a diameter of ~10 nm was obtained using a combination of two processes: high-temperature coprecipitation and hydrothermal treatment in an autoclave. The UCC was then PEGylated with PEG-alendronate (PEG-Ale) to facilitate its dispersion in aqueous cell culture media intended for in vitro cell uptake assays. The surface modification of the nanoparticles increased both the colloidal stability in water and the upconversion emission by mitigating surface quenching. UCC@Ale-PEG was characterized by transmission and scanning electron microscopy, dynamic light scattering, and fluorescence microscopy detecting upconversion photoluminescence emission. The results of an in vitro assay revealed that this new generation of UCC can be internalized by various cell types, including epithelial cells and macrophages, upon several hours of exposure, suggesting broad application potential of this type of UCC in biomedicine, bioengineering, and environmental sciences. Full article

Atypical femoral fractures (AFFs) are rare but increasingly recognised complications associated with prolonged bisphosphonate therapy. We present the imaging findings of a 64-year-old postmenopausal woman who developed bilateral femoral shaft stress injuries following long-term (4 years) alendronate use. Magnetic resonance imaging demonstrated Grade 3 stress injuries consistent with early incomplete atypical femoral fractures, with lateral cortical involvement and surrounding marrow oedema that preceded fracture completion. Radiographs confirmed an atypical transverse fracture pattern with lateral cortical beaking and minimal comminution. This case highlights the diagnostic value of MRI in detecting early stress-related changes prior to fracture completion, particularly in patients receiving antiresorptive therapy who present with prodromal thigh pain. Recognition of these imaging features is essential for early diagnosis, appropriate modification of osteoporosis treatment, and timely surgical intervention. Full article

Background/Objectives: Hydroxyapatite (HAp)-based implants and HAp–titanium (HApTi) composites are widely used in orthopedic and dental applications, but their long-term success is limited by peri-implant bone loss. Local delivery of osteoactive molecules from implant surfaces may enhance osseointegration and reduce periprosthetic osteolysis. This study combined in silico modeling and experimental assays to compare calcium fructoborate (CaFb), sodium alendronate, and calcium alendronate as functionalization agents for HAp and HApTi implants. Methods: Molecular docking (AutoDock 4.2.6) and 100 ns molecular dynamics (MD) simulations (AMBER14 force field, SPC water model) were performed to characterize ligand–substrate interactions and to calculate binding free energies (ΔG_binding) and root mean square deviation (RMSD) values for ligand–HAp/HApTi complexes. HAp and HApTi discs obtained by powder metallurgy were subsequently functionalized by surface adsorption with CaFb or alendronate salts. The amount of adsorbed ligand was determined gravimetrically, and in vitro release profiles were quantified by HPTLC–MS for CaFb and by HPLC after FMOC derivatization for alendronates. Results: CaFb–HAp and CaFb–HApTi complexes showed the lowest binding free energies (−1.31 and −1.63 kcal/mol, respectively), indicating spontaneous and stable interactions. For HAp-based complexes, the mean ligand RMSD values over 100 ns were 0.27 ± 0.17 nm for sodium alendronate, 0.72 ± 0.28 nm for calcium alendronate (range 0.35–1.10 nm), and 0.21 ± 0.19 nm for CaFb (range 0.15–0.40 nm). For HApTi-based complexes, the corresponding RMSD values were 0.30 ± 0.15 nm for sodium alendronate, 0.72 ± 0.38 nm for calcium alendronate and 0.26 ± 0.14 nm for CaFb. These distributions indicate that CaFb and sodium alendronate maintain relatively stable binding poses, whereas calcium alendronate shows larger conformational fluctuations, consistent with its less favorable binding energies. Experimentally, CaFb exhibited the greatest chemisorbed amount and percentage on both HAp and HApTi, followed by sodium and calcium alendronate. HApTi supported higher loadings than HAp for all ligands. Release studies demonstrated a pronounced burst and rapid plateau for both alendronate salts, whereas CaFb displayed a slower initial release followed by a prolonged, quasi-linear liberation over 14 days. Conclusions: The convergence between in silico and adsorption–release data highlights CaFb as the most promising candidate among the tested ligands for long-term functionalization of HAp and HApTi surfaces. Its stronger and more stable binding, higher loading capacity and more sustained release profile suggest that CaFb-coated HApTi implants may provide a favorable basis for future in vitro and in vivo studies aimed at improving osseointegration and mitigating periprosthetic osteolysis, although direct evidence for osteolysis prevention was not obtained in the present work. Full article

Osteoporosis is a systemic skeletal disease that severely impairs the health of the elderly population. The interaction between the receptor activator of the NF-κB ligand (RANKL) and its receptor RANK is critical for osteoclast differentiation and function. Therefore, targeting the RANKL/RANK interaction represents a promising strategy for osteoporosis. In this study, we employed a newly established yeast two-hybrid system based on RANKL/RANK interaction and identified IMB-R38, a novel benzamide compound that dose-dependently blocked RANKL/RANK interaction by inhibiting the growth of AH109 cells harboring pAD-RANKL/pBD-RANK plasmids in quadruple-dropout medium. IMB-R38 significantly suppressed osteoclast differentiation, disrupted F-actin ring formation, and downregulated the expression of osteoclast-specific genes, including NFATc1 and MMP9 in RANKL-induced RAW264.7 macrophages. IMB-R38 also promoted osteoblast differentiation by upregulating the expression of osteogenic genes. Importantly, in a dexamethasone (DXM)-induced osteoporotic zebrafish model, IMB-R38 significantly increased bone mineralization, with anti-osteoporosis efficacy superior to that of alendronate sodium (Alen). RT-qPCR assays showed that IMB-R38 significantly upregulated the mRNA expression of osteogenesis genes (Bmp2, Runx2a, Runx2b, Sp7, Alp, and Oc) while markedly downregulating that of the osteoclastogenesis genes (Mmp9, Mmp13, and Mmp2) compared with the DXM group. Mechanistically, an SPR assay confirmed that IMB-R38 directly binds with RANK but not RANKL to disrupt RANKL/RANK interaction. Furthermore, Asp168 of RANK was identified as a key amino acid that mediates both RANKL interaction and IMB-R38 binding. The inhibition of RANKL/RANK by IMB-R38 suppressed JNK phosphorylation and, consequently, osteoclast differentiation and function. Collectively, our findings identify IMB-R38 as a novel RANKL/RANK inhibitor with therapeutic potential for osteoporosis through its regulation of bone metabolism. Full article

Objectives: This study aimed to evaluate dentists’ knowledge in Split-Dalmatia County regarding bisphosphonates and their oral side effects. Methods: An anonymous, 20-item questionnaire assessing demographics, knowledge of indications, mechanisms of action, and complications of bisphosphonates was electronically distributed via email to dentists in Split-Dalmatia County between March and April 2025. Descriptive statistical analysis was performed, and the results are presented as absolute numbers and percentages. The Chi-square test was used to compare proportions between groups, with a significance level set at p < 0.05. Results: A total of 172 dentists from Split-Dalmatia County participated (response rate was 71.36%). The mean total knowledge score was 7.3 ± 1.4 out of 9 items. The results indicated that most respondents correctly answered questions about indications for bisphosphonate use (95.9%), mechanism of action (93.6%), and the most common complication—osteonecrosis of the jaw (92.4%). The lowest correct response rate (38.4%) was for procedures before invasive dental treatments. Only 18.6% of participants answered all nine knowledge questions correctly. No significant differences in knowledge were found based on gender, age, year of graduation, or educational level. Nearly all dentists (95.3%) expressed interest in further education on this topic. Conclusions: Although dentists demonstrated satisfactory general knowledge regarding bisphosphonates, important gaps remain, particularly in practical application, including recommendations for managing patients on bisphosphonates undergoing invasive dental procedures. Given the rising use of bisphosphonates and the potential severity of their side effects, additional education is warranted to enhance prevention, promote early detection, and ensure appropriate clinical management of related complications. Full article

Photodynamic therapy (PDT) is a highly selective, clinically approved, minimally invasive technique that effectively eliminates cancer cells. Its effectiveness is limited by poor light penetration into tissue and the hydrophobic nature of photosensitizers, highlighting the need for new approaches to treatment. Here, a theranostic upconversion nanoplatform, consisting of a NaYF₄:Yb,Er,Tm,Fe core and a NaHoF₄ shell codoped with Yb, Nd, Gd and Tb ions, was designed to enhance PDT outcomes by integrating multi-wavelength upconversion luminescence, T₂-weighted magnetic resonance imaging (MRI) and PDT. The synthesized core–shell upconversion nanoparticles (CS-UCNPs) were coated with new verteporfin (VP)-conjugated alendronate-terminated poly(N,N-dimethylacrylamide-co-2-aminoethyl acrylate) [Ale-P(DMA-AEA)] grafted with poly(ethylene glycol) (PEG). Under 980 nm NIR irradiation, CS-UCNP@Ale-P(DMA-AEA)-PEG-VP nanoparticles generated reactive oxygen species (ROS) due to the efficient energy transfer between CS-UCNPs and VP. In a pilot preclinical study, intratumoral administration of nanoparticle conjugates to mice, followed by exposure to NIR light, induced necrosis of pancreatic tumor and suppressed its growth. Full article

Cystic echinococcosis (CE) is an endemic zoonotic disease caused by Echinococcus granulosus, which forms cysts in ungulates’ intermediate hosts. Humans are accidental hosts, and CE affects more than one million people worldwide. Imaging remains the diagnostic gold standard, outperforming serological methods. This study presents an in silico analysis of two glyceraldehyde-3-phosphate dehydrogenase (GAPDH) isoenzymes from E. granulosus (EgGAPDH), isolated from a parasite cell line (EGPE). EgGAPDHs were recognized by sera from CE patients, identified through LC-MS/MS and PCR of metacestodes from cattle liver. One isoenzyme is intracellular (IC) (UniProt: W6UJ19), and the other is extracellular (EC) (UniProt: W6V1T8). GAPDH is involved in host–parasite interactions and metabolic processes. We characterized the physicochemical properties; linear epitopes (LEPs); and amino acid domains of EgGAPDH, its hosts, and other parasites. W6UJ19 emerged as the most promising isoenzyme as a marker of infection. Molecular dynamics simulations of isoenzymes, performed in the presence or absence of two bisphosphonates (BPs), revealed how drug binding alters conformational epitopes (CEPs) and suggested that W6UJ19 is more responsive to BP modulation. Binding affinity analysis using the MMPBSA method revealed that etidronate (EHDP) binds EgGAPDH with greater affinity than phosphate (Pi) and alendronate (AL), in the following order: EHDP > Pi > AL. Full article

Post-traumatic osteoarthritis (PTOA) is a distinct form of knee osteoarthritis characterized by accelerated joint degeneration following injury. It poses unique challenges in post-menopausal women due to hormonal changes and altered bone metabolism that create complex pathophysiological environments. This retrospective cohort study compared the effectiveness of different anti-osteoporotic medications in preventing total knee replacement (TKR) in 6155 postmenopausal women with PTOA treated between 2011 and 2021. We compared raloxifene and denosumab, with alendronate serving as the reference group. The primary outcome was TKR occurrence. Cox proportional hazards regression and inverse probability of treatment weighting (IPTW) were performed to estimate hazard ratios, with Kaplan–Meier survival analysis for time-to-event assessment. Participants’ mean (SD) age was 69.4 (10.0) years. Given the retrospective nature and typical delayed presentation of PTOA symptoms, cohort entry was defined as the concurrent diagnosis of PTOA and osteoporosis requiring anti-resorptive therapy. Over a mean follow-up of 5.47 years, 26 patients (0.42%) underwent TKR. Raloxifene was associated with a significantly reduced TKR risk compared to alendronate (IPTW-HR 0.81, 95% CI 0.67–0.99, p = 0.040), representing a 19% relative risk reduction. Kaplan–Meier analysis demonstrated raloxifene maintained the lowest cumulative TKR incidence compared to alendronate and denosumab over time, particularly beyond 5 years. These findings suggest that raloxifene may offer superior joint protection compared with alendronate and denosumab in postmenopausal women with PTOA, supporting its potential as a disease-modifying therapeutic option for this vulnerable population. Full article

Background/Objectives: Postmenopausal osteoporosis disrupts magnesium homeostasis and hematological balance, contributing to systemic inflammation and metabolic alterations. This study aimed to assess the effects of dietary interventions—tempeh, daidzein, probiotics, and their combinations—on magnesium status and hematological ratios in a postmenopausal osteoporotic Wistar rat model. Methods: Sixty-four rats were divided into one sham group (n = 8) and seven ovariectomized (OVX) groups (n = 56), with different modified diets administered for six weeks. In addition, one of the groups received alendronate bisphosphonate as a pharmacological reference to benchmark the dietary interventions against standard anti-osteoporotic therapy. Magnesium levels in the tissues and feces, along with blood hematological ratios (neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), and triglyceride-to-glucose index (TyG)), were evaluated. Results: The results revealed that a combination of tempeh and probiotics (OTL) significantly increased magnesium levels in the feces, spleen, and hair, while reducing liver magnesium levels. Compared to the standard groups (S and O), the hematological analysis revealed that the daidzein group (OD) had the highest MLR, while the OTL group exhibited the lowest TyG index. The alendronate bisphosphonate (OB) intervention showed no significant effect on tissue magnesium levels, feces magnesium levels, or hematological ratios. Correlation analysis revealed a strong negative association between spleen magnesium levels and the PLR (r = −0.626) and a positive relationship between liver magnesium levels and TyG (r = 0.422). Conclusions: The authors of this study concludes that while ovariectomy significantly altered magnesium status and hematological ratios, the dietary combination of tempeh, daidzein, and probiotics did not demonstrate an apparent beneficial effect on magnesium status or inflammatory ratios in a postmenopausal osteoporotic rat model. However, the findings highlight interesting aspects of magnesium status and its correlations with metabolic and inflammatory parameters, warranting further investigation. Full article

This study sought to evaluate the inhibitory effect of pulsed electromagnetic field (PEMF) therapy on bone resorption in a mouse model of lipopolysaccharide (LPS)-induced osteoporosis. A total of 40 mice were divided into four groups: control, LPS, LPS + alendronate, and LPS + PEMF. Blood and spleen samples were analyzed using RT-PCR and ELISA, while calvaria and femurs were assessed by micro-computed tomography (CT) and histological analysis. Serum analysis revealed that, compared with the control group, calcium levels in the PEMF group showed no significant difference, but alkaline phosphatase (ALP) levels were significantly increased, whereas tartrate-resistant acid phosphatase (TRAP) levels were significantly decreased. Moreover, blood cytokine analysis showed reduced expression of TNF-α and IL-1β and increased expression of BMP-2 in the PEMF group. Spleen tissue analysis further demonstrated significant upregulation of IFN-γ and IL-10 expression in the PEMF group. Micro-CT confirmed that PEMF inhibited femoral bone loss and promoted bone regeneration in calvarial defects. Histological evaluation with hematoxylin and eosin and Masson–Goldner trichrome staining confirmed enhanced bone formation in both the femur and calvaria. In conclusion, PEMF effectively alleviates bone loss and promotes bone regeneration in LPS-induced osteoporosis. Furthermore, PEMF exhibits anti-osteoclastogenic activity by reducing inflammatory cytokines and enhancing IFN-γ and IL-10 expression in the spleen. Full article

Background and Objectives: Bisphosphonates (BP) like zoledronic acid (ZA) and alendronic acid (AA) are used for osteoporosis (OP) or other bone-related conditions as well as to prevent the spread of metastases and in rheumatoid arthritis treatment. However, they have been associated with an increased risk of osteonecrosis of the jaw (ONJ). This systematic review aimed to assess the incidence and risk of ONJ in osteoporotic patients treated with ZA or AA and evaluate the impact of treatment duration. Material and Methods: The systematic literature review was conducted following PRISMA guidelines. The keywords “Zoledronic acid,” “Alendronic acid,” “Osteoporosis,” and “Osteonecrosis” were searched in PubMed and ScienceDirect databases. Selection criteria included studies on humans written in English, published from 2014. The systematic review protocol was registered in the PROSPERO register under the following number: CRD42024587046. Results: A total of 7 studies with 98,717 osteoporotic patients met the criteria, showing a higher ONJ incidence with ZA than AA. Six studies linked longer BP use to increased ONJ risk, which quadrupled after 5 years of AA use. A positive correlation was found between BP use (≥3 years) and ONJ in OP patients, primarily affecting females over 60. ONJ appeared after 1 year with AA, increasing over time, while ZA-related ONJ emerged as early as 5 months with a higher overall incidence. Conclusions: ZA poses a higher ONJ risk and incidence and earlier onset than AA, occurring within 5 months versus 1 year for AA. These findings emphasize the need for careful monitoring, especially in long-term BP therapy with additional risk factors. Full article

Background: We report the successful formulation of a bone-targeted vancomycin-loaded liposomal carrier. Method: The basic liposomal structure is composed of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), cholesterol, and dicetyl phosphate (DCP) in a molar ratio of 3:1:0.25, respectively. The dehydration–rehydration method was used to maximize the liposomal-encapsulation efficiency of vancomycin after the initial preparation using thin-film hydration. Results: Sodium alendronate was used as a targeting moiety and was successfully conjugated to DSPE–PEG–COOH via carbodiimide chemistry, as was confirmed using IR spectroscopy. The resulting conjugate, DSPE–PEG-alendronate, was subsequently used in the formulation of bone-targeting vancomycin-loaded liposomes. In vitro binding assays with hydroxyapatite demonstrated preferential binding of the surface-modified liposomes to hydroxyapatite crystals. Furthermore, ex vivo studies revealed that the surface-modified liposomes exhibited enhanced binding affinity to the tibial bone tissue of 4-week-old male CD1 mice, in comparison to unmodified liposomes. Conclusions: The successfully formulated surface-modified vancomycin loaded liposomes showed enhanced bone affinity with a great potential for targeting the antibiotic to infected bones. Full article

Introduction: Bone health optimization is a key component of the preoperative management of spine surgery patients, as poor bone quality increases the odds of mechanical complications. The present study aimed to achieve the following: (1) compare the relative efficacy of current osteoporosis medications in improving bone quality; (2) identify factors influencing treatment response in preoperative spine surgery patients. Methods: Patients treated at a single, multisite institution who received osteoporosis treatment were identified. Data were gathered on pre- and post-treatment lumbar spine Hounsfield Unit (HU) measurements, patient demographics, frailty scores (modified Frailty Index/mFI, risk analysis index/RAI), and pharmacologic treatment details. The primary outcome was a ≥7 point improvement in lumbar HU, and baseline and logistic regression models were utilized to identify factors associated with this improvement. Medications were grouped as anabolic (teriparatide, romosozumab) and antiresorptive (denosumab, alendronate) therapies. Results: A total of 267 patients were included (median age: 74 years; IQR [66–81]; 67.3% female), with 127 (47.6%) improving by ≥7 HU. The treatment agents used were alendronate (95), denosumab (113), romosozumab (31), and teriparatide (28). Univariable comparisons revealed significant differences across medication groups in age (p < 0.001), sex (p < 0.001), mFI (p < 0.001), RAI (p = 0.004), BMI (p < 0.001), pre-treatment HU (p = 0.022), and treatment duration (p < 0.001). The highest HU improvement rates (ΔHU ≥ 7) were observed in patients receiving the anabolic medications romosozumab (67.7%) and teriparatide (60.7%). Univariable logistic regression identified male sex (OR 0.54, p = 0.019), higher pre-treatment HU (OR 0.99, p = 0.006), and longer treatment duration (OR 0.97, p = 0.003) as factors associated with lower odds of HU improvement. Only romosozumab was associated with significantly higher odds of HU improvement relative to alendronate (OR 3.02, p = 0.012). In our multivariable analysis, male sex (OR 0.53, p = 0.028) and higher pre-treatment HU (OR 0.99, p = 0.002) remained significant predictors of HU improvement. However, medication type was not significant in the multivariable analysis. Conclusions: Our study highlights that male sex and higher pre-treatment HU were independently associated with lower odds of HU improvement, while medication type was not a significant predictor. Additionally, anabolic agents offered superior improvement relative to antiresorptive therapies. Full article