Complex Bone Diseases Research Articles

Improving Biological Performance of 3D-Printed Scaffolds with Garlic-Extract Nanoemulsions.

Complex bone diseases such as osteomyelitis, osteosarcoma, and osteoporosis often cause critical-size bone defects that the body cannot self-repair and require an advanced bone graft material to repair. We have fabricated 3D-printed tricalcium phosphate bone scaffolds functionalized with garlic extract (GE). GE was encapsulated in a nanoemulsion (GE-NE) to enhance bioavailability and stability. GE-NE showed ∼73% drug encapsulation efficiency, with an average particle size of 158 nm and a zeta potential of -14.2 mV. Release of GE-NEs from the scaffold displayed a controlled and biphasic release profile at both acidic and physiological mediums. Results from the osteosarcoma study show that GE-NE demonstrated ∼88% reduction in cancer cell growth while exhibiting no cytotoxicity toward bone-forming cells. Interaction for the functionalized scaffold with Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa showed a substantial reduction in bacteria growth by more than 90% compared to the unfunctionalized scaffold. These findings demonstrate the potential of GE-NEs-treated porous scaffolds to treat bone-related diseases, particularly for non-load bearing applications.

Bioactive nanocomposite hydrogel enhances postoperative immunotherapy and bone reconstruction for osteosarcoma treatment

Osteosarcoma, a malignant bone tumor often characterized by high hedgehog signaling activity, residual tumor cells, and substantial bone defects, poses significant challenges to both treatment response and postsurgical recovery. Here, we developed a nanocomposite hydrogel for the sustained co-delivery of bioactive magnesium ions, anti-PD-L1 antibody (αPD-L1), and hedgehog pathway antagonist vismodegib, to eradicate residual tumor cells while promoting bone regeneration post-surgery. In a mouse model of tibia osteosarcoma, this hydrogel-mediated combination therapy led to remarkable tumor growth inhibition and hence increased animal survival by enhancing the activity of tumor-suppressed CD8+ T cells. Meanwhile, the implanted hydrogel improved the microenvironment of osteogenesis through long-term sustained release of Mg2+, facilitating bone defect repair by upregulating the expression of osteogenic genes. After 21 days, the expression levels of ALP, COL1, RUNX2, and BGLAP in the Vis-αPD-L1-Gel group were approximately 4.1, 5.1, 5.5, and 3.4 times higher than those of the control, respectively. We believe that this hydrogel-based combination therapy offers a potentially valuable strategy for treating osteosarcoma and addressing the tumor-related complex bone diseases.

A tetrahedral DNA nanostructure-mediated miRNA inhibitor delivery system: Type H vessel-related bone healing during distraction osteogenesis

The clinical treatment of critical bone defects presents a great challenge, and distraction osteogenesis (DO) emerges as a highly effective strategy. However, prolonged consolidation periods resultant complications limit its clinical applicability. MicroRNA (miR) therapeutic strategies, with a notable focus on miR-205, demonstrate significant potential during DO. Nevertheless, the limited cellular uptake and facile biodegradation of miRNA constrain its applications. To address these challenges, we introduce tetrahedral DNA nanostructure (TDN), an innovative nanomaterial, engineered as gene carriers. TDN delivers the miR-205 inhibitor (TDN@miR205) to synthesize the novel nanoparticles that support bone healing for the first time. TDN@miR205 enhances the osteogenic potential of bone marrow-derived mesenchymal stem cells (BMSCs), whereas TDN alone is ineffective. Further exploration reveals TDN-modulated angiogenesis-osteogenesis communication, establishing a crucial intercellular regulatory mechanism. Notably, TDN@miR205 expedites bone formation by promoting type H vessels-related angiogenesis, secreting SLIT3 to inhibit osteoclasts, inducing SDF1 homing of BMSCs, then upregulating osteogenic genes and proteins via the TGF-β/BMP pathway, facilitating early bony ossification both in vitro and in vivo. In conclusion, TDN@miR205, the multifunctional nanoparticle-mediated vascular bone regeneration significantly contributes to ossification in DO and establishes this platform as a promising and versatile strategy for addressing DO and other complex bone diseases.

Organoid extracellular vesicle-based therapeutic strategies for bone therapy.

With the rapid development of population ageing, bone-related diseases seriously affecting the life of the elderly. Over the past few years, organoids, cell clusters with specific functions and structures that are self-induced from stem cells after three-dimensional culture in vitro, have been widely used for bone therapy. Moreover, organoid extracellular vesicles (OEVs) have emerging as promising cell-free nanocarriers due to their vigoroso physiological effects, significant biological functions, stable loading capacity, and great biocompatibility. In this review, we first provide a comprehensive overview of biogenesis, internalisation, isolation, and characterisation of OEVs. We then comprehensively highlight the differences between OEVs and traditional EVs. Subsequently, we present the applications of natural OEVs in disease treatment. We also summarise the engineering modifications of OEVs, including engineering parental cells and engineering OEVs after isolation. Moreover, we provide an outlook on the potential of natural and engineered OEVs in bone-related diseases. Finally, we critically discuss the advantages and challenges of OEVs in the treatment of bone diseases. We believe that a comprehensive discussion of OEVs will provide more innovative and efficient solutions for complex bone diseases.

How Efficient are Alendronate-Nano/Biomaterial Combinations for Anti-Osteoporosis Therapy? An Evidence-Based Review of the Literature.

Osteoporosis is defined as a systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture. Because of the systemic nature of osteoporosis, the associated escalation in fracture risk affects virtually all skeletal sites. The problem is serious since it is estimated that more than 23 million men and women are at high risk of osteoporotic-like breakages in the European Union. Alendronate (ALN) is the most commonly prescribed oral nitrogen-containing bisphosphonate (BP) for the prevention and the therapy of osteoporosis. This is also one of the most intensely studied drugs in this field. However, ALN is characterized by restricted oral absorption and bioavailability and simultaneously its administration has serious side-effects (jaw osteonecrosis, irritation of the gastrointestinal system, nausea, musculoskeletal pain, and cardiovascular risks). Therefore, delivery systems enabling controlled release and local action of this drug are of great interest, being widely researched and presented in the literature. In this review, we discuss the current trends in the design of various types of alendronate carriers. Our paper is focused on the most recent developments in the field of nano/biomaterials-based systems for ALN delivery, including nano/microformulations, synthetic/natural polymeric and inorganic materials, hydrogel-based materials, scaffolds, coated-like structures, as well as organic-inorganic hybrids. Topics related to the treatment of complex bone diseases including osteoporosis have been covered in several more general reviews; however, the systems for this particular drug have not yet been discussed in detail.

The role of metabolites under the influence of genes and lifestyles in bone density changes.

PurposeOsteoporosis is a complex bone disease influenced by numerous factors. Previous studies have found that some metabolites are related to bone mineral density (BMD). However, the associations between metabolites and BMD under the influence of genes and lifestyle have not been fully investigated.MethodsWe analyzed the effect of metabolites on BMD under the synergistic effect of genes and lifestyle, using the data of 797 participants aged 55–65 years from the Taizhou Imaging Study. The cumulative sum method was used to calculate the polygenic risk score of SNPs, and the healthful plant-based diet index was used to summarize food intake. The effect of metabolites on BMD changes under the influence of genes and lifestyle was analyzed through interaction analysis and mediation analysis.ResultsNineteen metabolites were found significantly different in the osteoporosis, osteopenia, and normal BMD groups. We found two high-density lipoprotein (HDL) subfractions were positively associated with osteopenia, and six very-low-density lipoprotein subfractions were negatively associated with osteopenia or osteoporosis, after adjusting for lifestyles and genetic factors. Tea drinking habits, alcohol consumption, smoking, and polygenic risk score changed BMD by affecting metabolites.ConclusionWith the increased level of HDL subfractions, the risk of bone loss in the population will increase; the risk of bone loss decreases with the increased level of very-low-density lipoprotein subfractions. Genetic factors and lifestyles can modify the effects of metabolites on BMD. Our results show evidence for the precise prevention of osteoporosis.

Multitarget-Based Virtual Screening for Identification of Herbal Substances toward Potential Osteoclastic Targets

Osteoporosis is a complex bone disease indicating porous bone with low bone mass density and fragility. Cathepsin K, V-ATPase, and αVβ3 integrin are exhibited as novel targets for osteoporosis treatment. Our preliminary study uses a state-of-the-art method, including target-based virtual screening and clustering methods to determine promising candidates with multitarget properties. Phytochemicals with osteoprotective properties from the literature are used to elucidate the molecular interactions toward three targets. The binding scores of compounds are normalized and rescored. The K-means and hierarchical clustering methods are applied to filter and define the promising compounds, and the silhouette analysis is supposed to validate the clustering method. We explore 108 herbal compounds by virtual screening and the cluster approach, and find that rutin, sagittatoside A, icariin, and kaempferitrin showed strong binding affinities against Cathepsin K, V-ATPase, and αVβ3 integrin. Dockings of candidates toward three targets also provide the protein-ligand interactions and crucial amino acids for binding. Our study provides a straightforward and less time-consuming approach to exploring the new multitarget candidates for further investigations, using a combination of in silico methods.

Genomic Medicine: Lessons Learned From Monogenic and Complex Bone Disorders.

Current genetic studies of monogenic and complex bone diseases have broadened our understanding of disease pathophysiology, highlighting the need for medical interventions and treatments tailored to the characteristics of patients. As genomic research progresses, novel insights into the molecular mechanisms are starting to provide support to clinical decision-making; now offering ample opportunities for disease screening, diagnosis, prognosis and treatment. Drug targets holding mechanisms with genetic support are more likely to be successful. Therefore, implementing genetic information to the drug development process and a molecular redefinition of skeletal disease can help overcoming current shortcomings in pharmaceutical research, including failed attempts and appalling costs. This review summarizes the achievements of genetic studies in the bone field and their application to clinical care, illustrating the imminent advent of the genomic medicine era.

Bone microarchitecture in patients undergoing parathyroidectomy for management of secondary hyperparathyroidism

BackgroundSecondary hyperparathyroidism (SHPT) in patients with chronic kidney disease (CKD) leads to complex bone disease, affecting both trabecular and cortical bone, and increased fracture risk. Optimal assessment of bone in patients with CKD is yet to be determined. High-resolution magnetic resonance imaging (MRI) can provide three-dimensional assessment of bone microarchitecture, as well as determination of mechanical strength with finite element analysis (FEA). MethodsWe conducted a single-centre, cross-sectional study to determine bone microarchitecture with MRI in CKD patients with SHPT undergoing parathyroidectomy. Within two weeks of surgery, MRI was performed at the distal tibia and biochemical markers of SHPT (parathyroid hormone [PTH] and alkaline phosphatase [ALP]) were collected. Trabecular and cortical topological parameters as well as bone mechanical competence using FEA were assessed. Correlation of MRI findings of bone was made with biochemical markers. ResultsTwenty patients with CKD (15 male, 5 female) underwent MRI at the time of parathyroidectomy (16 on dialysis, 3 with functioning kidney transplant, one pre-dialysis with CKD stage 5). Median PTH at the time of surgery was 138.5 pmol/L [39.6–186.7 pmol/L]. MRI parameters in patients were consistent with trabecular deterioration, with erosion index (EI) 1.01 ± 0.3, and trabecular bone volume (BV/TV) 10.8 ± 2.9%, as well as poor trabecular network integrity with surface-to-curve ratio (S/C) 5.4 ± 2.3. There was also evidence of reduced cortical thickness, with CTh 2.698 ± 0.630 mm, and FEA demonstrated overall poor bone mechanical strength with mean elastic modulus of 2.07 ± 0.44. ConclusionPatients with severe SHPT requiring parathyroidectomy have evidence of significant changes in bone microarchitecture with trabecular deterioration, low trabecular and cortical bone volume, and reduced mechanical competence of bone.

Mesoporous Silica Nanoparticles for the Treatment of Complex Bone Diseases: Bone Cancer, Bone Infection and Osteoporosis.

Bone diseases, such as bone cancer, bone infection and osteoporosis, constitute a major issue for modern societies as a consequence of their progressive ageing. Even though these pathologies can be currently treated in the clinic, some of those treatments present drawbacks that may lead to severe complications. For instance, chemotherapy lacks great tumor tissue selectivity, affecting healthy and diseased tissues. In addition, the inappropriate use of antimicrobials is leading to the appearance of drug-resistant bacteria and persistent biofilms, rendering current antibiotics useless. Furthermore, current antiosteoporotic treatments present many side effects as a consequence of their poor bioavailability and the need to use higher doses. In view of the existing evidence, the encapsulation and selective delivery to the diseased tissues of the different therapeutic compounds seem highly convenient. In this sense, silica-based mesoporous nanoparticles offer great loading capacity within their pores, the possibility of modifying the surface to target the particles to the malignant areas and great biocompatibility. This manuscript is intended to be a comprehensive review of the available literature on complex bone diseases treated with silica-based mesoporous nanoparticles—the further development of which and eventual translation into the clinic could bring significant benefits for our future society.

Osteoimmunology and the influence of pro-inflammatory cytokines on osteoclasts

Bone and immune system are functionally interconnected. Immune and bone cells derive from same progenitors in the bone marrow, they share a common microenvironment and are being influenced by similar mediators. The evidence on increased bone resorption associated with inappropriate activation of T cells such as during inflammation, is well established. However, the molecular mechanisms beyond this clinical observation have begun to be intensively studied with the advancement of osteoimmunology. Now days, we have firm evidence on the influence of numerous proinflammatory cytokines on bone cells, with the majority of data focused on osteoclasts, the bone resorbing cells. It has been shown that some proinflammatory cytokines could possess osteoclastogenic and/or anti-osteoclastogenic properties and can target osteoclasts directly or via receptor activator of nuclear factor κB (RANK)/RANK ligand(RANKL)/osteoprotegerin (OPG) system. Several studies have reported opposing data regarding (anti)osteoclastogenic properties of these cytokines.Therefore, the first part of this review is summarizing current evidence on the influence of pro-inflammatory cytokines on osteoclasts and thus on bone resorption. In the second part, the evidence on the role of pro-inflammatory cytokines in osteoporosis and osteoarthritis is reviewed to show that unravelling the mechanisms beyond such complex bone diseases, is almost impossible without considering skeletal and immune systems as an indivisible integrated system.

Modelling the anabolic response of bone using a cell population model

To maintain bone mass during bone remodelling, coupling is required between bone resorption and bone formation. This coordination is achieved by a network of autocrine and paracrine signalling molecules between cells of the osteoclastic lineage and cells of the osteoblastic lineage. Mathematical modelling of signalling between cells of both lineages can assist in the interpretation of experimental data, clarify signalling interactions and help develop a deeper understanding of complex bone diseases. Several mathematical models of bone cell interactions have been developed, some including rank–rankl–opgsignalling between cells and systemic parathyroid hormone pth. However, to our knowledge these models do not currently include key aspects of some more recent biological evidence for anabolic responses. In this paper, we further develop a mathematical model of bone cell interactions by Pivonka et al. (2008) to include the proliferation of precursor osteoblasts into the model. This inclusion is important to be able to account for wntsignalling, believed to play an important role in the anabolic responses of bone. We show that an increased rate of differentiation to precursor cells or an increased rate of proliferation of precursor osteoblasts themselves both result in increased bone mass. However, modelling these different processes separately enables the new model to represent recent experimental discoveries such as the role of wntsignalling in bone biology and the recruitment of osteoblast progenitor cells by transforming growth factor β. Finally, we illustrate the power of the new model's capabilities by applying the model to prostate cancer metastasis to bone. In the bone microenvironment, prostate cancer cells are believed to release some of the same signalling molecules used to coordinate bone remodelling (i.e.,wntand pthrp), enabling the cancer cells to disrupt normal signalling and coordination between bone cells. This disruption can lead to either bone gain or bone loss. We demonstrate that the new computational model developed here is capable of capturing some key observations made on the evolution of the bone mass due to metastasis of prostate cancer to the bone microenvironment.

Recommended Fluid Intake Should Be Tailored to the Individual

We wish to comment on two critical issues in this otherwise excellent article. Complex bone disease after renal transplantation (NTX) is not the same as steroid induced osteoporosis. Bisphosphonates after NTX should not be used in analogy to the guidelines from the umbrella organization for osteology (Dachverband Osteologie, DVO e.V.) as a general rule (use during steroid treatment >3 months or in patients with an osteoporotic fracture + T score <-1.5), because: Although bone density after NTX increases when bisphosphonates are given, this is not a good predictor for fractures after NTX, and a drop in the incidence of fractures has not been shown (1). Adynamic bone disease is the most common bone pathology in dialysis patients. It often persists after NTX. Using antiresorptive drugs in such situations seems a questionable approach (long term complications?) (2). The optimum dosage and duration of bisphosphonate use, and the best administration method, remain unclear. Current nephrology guidelines (KDOQI, Kidney Disease Outcome Quality; KDIGO, Kidney Disease Improving Global Outcomes; EBPG, European Best Practise Guidelines) do not provide a clear recommendation for the use of bisphosphonates after NTX. In an NTX patient with unsuppressed bone metabolism who is at a high risk of fractures, bisphosphonates certainly feature among the individualized treatment options. In addition to bone densitometry, however, clinical risk factors should be included in any assessment of fracture risk. The cornerstones of therapy primarily include adjusting immunosuppression, optimizing renal osteodystrophy therapy, physical activity, and preventing falls. A global recommendation for fluid intake of more than 2 liters/day should be made on an individual basis only. It is indicated in NTX patients with recurrent urinary tract infections, for example. On the other hand, reports are increasing that in patients with impaired renal function, drinking more than 2 L/d accelerates the further loss of kidney function (3). Although this has not been the subject of formal studies in the context of NTX, we think that a daily intake of 1.5–2 L is sufficient in most renal transplant patients.

Clinical and molecular variability in congenital dyserythropoietic anaemia type I

Congenital dyserythropoietic anaemia (CDA) type I is a rare, inherited disorder characterised by ineffective erythropoiesis and macrocytic anaemia. Complex bone disease has only occasionally been associated with this disease. CDA I is caused by mutations in the CDAN1 gene encoding for codanin-1. Our aim was to characterise the CDAN1 mutation in eight unrelated patients with sporadic CDA I, three of whom had complex bone disease. Six novel mutations in the CDAN1 gene were identified. In two patients, one mutation and in another, both mutations were elusive. No patient was homozygous for a null-type mutation. However, one patient with complex bone disease was homozygous for a splice-site mutation (IVS-12+5G>A). Western blotting revealed that codanin-1 synthesis was 65% less than the control. Five single nucleotide polymorphisms (SNPs) previously unreported in the literature or the SNP database were also identified. Although the absence of codanin-1 is probably lethal, the presence of 35% of the protein was compatible with life but was associated with severe clinical manifestations. However, in most patients studied, no correlation could be established between the expected levels of codanin-1 or the nature of the mutation and the severity of the clinical manifestations.

Molecular Basis of Congenital Dyserythropoietic Anemia Type I in French Patients.

Congenital dyserythropoietic anemia type I (CDA I) is an inherited disorder characterized by macrocytic anemia and occasionally also by distal bone malformations. The disease has recently been shown to be caused by mutations in the CDAN1 gene, encoding codanin-1. The aim of the study was to characterize the CDAN1 mutations in 12 French patients with CDA I. The clinical data of the 12 French patients (10 kindreds) with CDA I were reviewed. Each of the 28 CDAN1 exons was amplified and sequenced. Half of the patients had a severe disease with prominent neonatal manifestations, complex bone disease, or both. Nine disease-causing mutations were identified: 6 described previously (P1130L, P671L, F869I, R681X, R713W, S1034F) and 3 novel mutations (R687W, F52L and IVS 8 G to A). Seven were missense mutations located in exons 14 to 28. Twenty seven per cent were identified in exon 14. No patient was homozygous for null type mutations. Only in two monozygotic twin patients did we fail to uncover a mutation. Mutations P671L, F52L and R713W were found on four, two and two alleles, respectively. One of the P671L alleles carried a second mutation (R687W). In conclusion the CDAN1 gene is apparently involved in most cases of CDA I in the French patients explored. Our study supports the previous findings that homozygosity for the null type mutations may be lethal, and that CDAN1 mutations are localized mainly in exons 12–28. In the present small group of patients, no apparent phenotype-genotype correlations were observed, in particular concerning abnormalities of the bones. Analysis of a larger number of patients from different ethnic groups is required to further characterize phenotype-genotype correlation in CDA I.