La fibrogenesis imperfecta ossium (FIO) è un disordine osteosclerotico raro e progressivo, coinvolgente l’intero scheletro, ad esito fatale, che colpisce gli adulti nelle decadi centrali della vita. Osservata per la prima volta nel 1938, venne successivamente descritta nel 1950 su base isto-patologica ma ricevette il suo acronimo solo nel 1966 e, da allora, ne sono stati descritti 29 casi. Sino dai primi due pazienti, emersero fratture spontanee e osteoide immaturo, che sostituiva il tessuto osseo a partire dall’endostio corticale sino al midollo rosso, in assenza di mineralizzazione come in corso di osteomalacia ma presenza di fibrille argirofile/aureofile, irregolari e prive di birifrangenza tipica del collagene. Data l’incertezza sull’eziopatogenesi, la malattia è stata trattata con differenti molecole ad azione osteoanabolica quali vitamina D, fluoruro di sodio, testosterone e GH ricombinante, ad oggi considerato il più promettente, mentre risultati trascurabili sono stati raggiunti con farmaci antiriassorbitivi (calcitonina, bisfosfonati). Risposte a glucocorticoidi e agenti alchilanti suggeriscono la presenza di una componente osteoimmunomodulatoria, rendendo la FIO un modello naturale per indagare il ruolo delle differenti fasi del rimodellamento osseo nel raggiungimento di una massa minerale efficiente e il tipo di terapie necessarie a questo obiettivo.

Intracellular drug therapies are based on the use of nanocarriers that can successfully penetrate cell barriers and release therapeutic payloads directly inside the cell environment. In this context, hydroxyapatite (HA) nanoparticles provide a particularly promising platform owing to their inherent biocompatibility, bioactivity, and drug-binding capability. This work hence examines anisotropic HA nanorods (NRs), synthesized using hydrothermal methods, with a particular focus on Mg-to-Ca ion substitution, aiming to increase the bioactivity and improve the interaction with therapeutics, specifically targeting intracellular sustained release. Our findings indicate that increasing the extent of Mg doping in apatite NRs induces enhanced cell compatibility and interaction with primary human bone marrow-derived mesenchymal stem cells. Moreover, the doping with Mg2+ enhances the NRs capacity to link and release doxorubicin, a widely used antitumor drug, in human osteosarcoma cells. The enhanced functionality is attributed to the Mg2+-induced structural disorder at the NR surface, which reduces the crystallinity and increases the number of reactive surface sites. As a result, Mg2+ doping has emerged as a promising strategy for optimizing the functional performance of apatite-based nanocarriers, highlighting their potential applications in nanomedicine and precision medicine.

Renal cell (RCC) and breast carcinoma (BC) frequently develop lytic bone metastases (BM) that are usually treated with systemic and locoregional therapies. Surgery plays a crucial role when pathological fractures or lesions involve a load-bearing bone and consists in the removal of tumor area followed by replacement with implant or prosthesis. In the present study, a proof of concept of novel locoregional therapies for BM patients was evaluated, consisting in the functionalization of biomorphic apatitic scaffolds with proved intrinsic regenerative properties with Everolimus and an anti-RANKL antibody, selected as relevant anticancer and anti-resorptive biomolecules, respectively. Upon confirmation of the biocompatibility of unloaded scaffolds with healthy bone cells, the effective antitumoral activity of released EVE on BC cell lines (MCF-7 and MDA-MB-231) and RCC cell line (Caki-2) was demonstrated. The inhibitory effects of drugs on osteoclast differentiation were validated using peripheral blood mononuclear cells (PBMCs). Preclinical validation was performed on monocultures and cocultures of cancer and bone cells sharing the same culture medium. In silico analyses were exploited to predict cancer cell behavior on medicated scaffolds providing complementary insights while reducing the need for extensive wet-lab experimentation. Finally, as a preliminary proof of translational relevance, the medicated scaffolds were tested with RCC patient-derived explants.

Calcium-phosphate (CaP) scaffolds are widely regarded as the gold standard in orthopedics due to their biomimetic properties. However, next-generation bone substitutes should be multifunctional, promoting bone regeneration while simultaneously preventing post-surgical infections. This study investigates the interplay between physico-chemical properties, surface structure/-texture and hydrophilicity in modulating bacterial adhesion on two CaP-based scaffolds: a biomorphic non-sintered scaffold (GB) and a sintered MgSr-CaP ceramic scaffold. Surface morphology and topography were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM), while ionic release profiles were quantified by inductively coupled plasma optical emission spectroscopy (ICP-OES) and related to the surface activity. A computer-vision-based approach using Haralick texture descriptors was applied to quantitatively analyze surface features. Antibacterial performance was evaluated against Staphylococcus aureus (including MRSA), Escherichia coli, and Pseudomonas aeruginosa by quantifying colony-forming units (CFUs) after 6 h and by SEM and time-lapse confocal imaging. The GB scaffold significantly reduced bacterial adhesion compared with MgSr-CaP scaffold. Pearson correlation analysis further demonstrated that Haralick-derived texture features are strong predictors of bacterial attachment behavior. These findings highlight the potential of biomorphic fabrication strategies combined with advanced surface texture analysis to guide the design of next-generation infection-resistant orthopedic biomaterials.

Small interfering RNAs (siRNAs) are particularly attractive among the frontier drugs due to their high specificity of action, activity on disease-inducing genes, and small molecular weight, thus being one of the most studied agents for gene therapy. However, siRNAs are prone to fast enzymatic degradation in the bloodstream, as well as other limitations that challenge their clinical translation. Nanoparticle (NP) delivery of siRNA has been proposed as a potential solution, overcoming their intrinsic limitations. In this regard, the siRNA delivery by magnetic nanoparticles is of particular interest because, being susceptible to external magnetic fields, it may be guided remotely, maximizing transfection efficiency and minimizing side effects. In addition, magnetic NPs would also allow a theranostic combination of drug delivery, magnetic resonance imaging, and hyperthermia. In this work we have studied the uptake of a model therapeutic siRNA by iron-doped hydroxyapatite nanoparticles (FeHA NPs), which are known to have excellent biocompatibility and magnetic susceptibility. We discovered that FeHA NPs stabilized by citrate (Cit-FeHA NPs) uptake siRNA by adsorption quickly and with high efficiency (ca. 90%) without altering nanoparticles physicochemical properties or colloidal stability. SiRNA-loaded Cit-FeHA NPs are able to slowly release their payload, with a sustained release of 45 days without siRNA degradation. Our work is therefore the preliminary validation of the suitability of FeHA NPs for magnetically guided delivery of therapeutic siRNAs.

Bone infections are a major complication in the treatment of bone defects, often leading to chronic conditions such as osteomyelitis and prosthetic joint infections, predominantly caused by Staphylococcus aureus bacteria. Whilst antibiotics are essential to infection control, systemic administration often fails to achieve effective concentrations at the infection site, increasing the risk of toxicity and antimicrobial resistance. In this study we propose a hybrid, scaffold obtained by a bio-inspired mineralization process (HS), designed to support bone healing and enabling localized antibiotic delivery. The HS consist of nanocrystalline magnesium-doped apatite nanocrystals heterogeneously nucleated on self-assembling collagen fibrils, mimicking natural bone mineralization processes. The scaffold is subsequently tested for its ability to modulate the release of vancomycin, gentamicin, and tobramycin and evaluate their efficacy in inhibiting Staphylococcus aureus growth by agar diffusion test. Antibiotic loading using clinically applicable methods and tracking their release over time was inspected and the experimental data was analysed using pseudo-first and pseudo-second order kinetics, showing pathways related to HS chemistry, structure, and drug physicochemical properties. Compared to burst antibiotic releases observed in sintered apatite scaffold, the hybrid scaffold demonstrated a more controlled and sustained release of antibiotics. Our findings highlight how scaffold nanostructure and surface characteristics can influence drug release, with regenerative capacity and sustained local antibiotic delivery potentially improving bone repair by reducing post-surgical infections.

Bone regeneration in oral surgery remains a challenge, due to the features of the oral environment, characterized by the presence of saliva and extensive interaction with external pathogens. Recent advances in this field highlighted that biomimetic apatites in which Ca2+ is replaced by Fe2+/Fe3+ ions are promising candidates to guide bone regeneration with on demand activation control. In this study the Fe-doped apatite nanoparticles (FeHA) were developed and compared with magnetite nanoparticles, as new magnetic bio-activator, to be embedded in apatitic injectable paste/cement. Upon self-hardening, the new injectable cement generates a mechanically competent 3D superparamagnetic scaffold, endowed with remote activation by using static magnetic fields. We investigated the alkaline phosphatase expression and activity, as well as the behaviour of cells, when seeded onto the scaffold. The results show the ability of the cement to stimulate cell colonization and differentiation and how, when magnetized, they can further boost such phenomena. The proposed devices, in association with a magnetic aligner, can represent a new approach in oral surgery, able to tune the bone remodelling on demand, when the regenerative potential is impaired by physiological conditions such as aging or chronic diseases.

Aging, diseases, or immunodeficiency’s can significantly impair the physiological regenerative process and the endogenous regenerative potential of bone tissue. Intensive research focuses on developing scaffolds that fill bone gaps while promoting cellular interaction and guiding tissue regeneration. Biomimicry is today widely acknowledged as a leading concept to develop novel approaches based on biomimetic materials to fabricate smart devices with advanced performance and multiple bio-functionalities. In the pursuit of designing smart devices for more efficient and personalized therapies, magnetic materials are eliciting growing interest due to the possibility of direct cell stimulation by magnetic fields or even for developing novel tools for the on-demand activation of implanted magnetic devices. There is a growing focus on understanding the impact of immune responses and the role of immunomodulators in the healing and regeneration of bone tissue.The relevance of biomimicry, immune and tissue responses to magnetic scaffolds and stimulation, alongside an examination of the limitations of existing bone substitutes in the market is highlighted. Biomimetic and magnetically activated scaffolds hold promise as innovative tools in addressing bone tissue diseases and promoting regeneration by effectively engaging in cellular and immunological responses.

Herein, hydroxyapatite and carbonate hydroxyapatite with calcium ions partially substituted by Mg2+ and Sr2+ ions were prepared by a wet-precipitation method and then calcined at different temperatures (from 300 degrees to 600 degrees C). The effect of ion substitution and carbonation of hydroxyapatite on the surface properties of the obtained samples was studied as a function of thermal treatment, with particular focus on surface acidity and basicity, using a multi-technique approach. Adsorption microcalorimetric-volumetric gas-solid measurements with ammonia and sulfur dioxide probes, liquid-solid acid-base titrations with phenylethylamine and benzoic acid in cyclohexane, infrared spectroscopy, thermogravimetric analysis, N2 adsorption-desorption isotherms were complementarily used. All the samples studied, both with and without carbonation, exhibited the characteristic amphoteric behavior of hydroxyapatite materials, with a slight predominance of basic sites (B) over acidic ones (A), as reflected by an A/B ratio of approximately 0.77. Microcalorimetric measurements further confirmed the amphoteric nature of the samples, showing that although acidic sites were more numerous, the basic sites exhibited greater strength compared to the acidic ones. The results show that multiple ion doping does not disrupt the typical amphoteric character of hydroxyapatites and this supports the applicability of apatites derived from food industry bio-waste.

Small interfering RNAs (siRNAs) provide strong therapeutic potential due to their efficient gene-silencing properties; however, their instability limits clinical application. Nanoparticle carriers may overcome this problem; in particular, magnetic nanoparticles show great promise as they can be directed to the target sites by external magnetic fields, thus improving delivery efficiency and reducing off-target effects. In addition, magnetic nanoparticles offer a novel nanoplatform for theranostic applications, integrating siRNA delivery with magnetic resonance imaging and magnetic hyperthermia for synergistic diagnostic and therapeutic advantages. The present work reports the development of a novel platform based on biomimetic magnetic nanoparticles made of Fe(II)/Fe(III)-doped apatite (FeHA) nucleated and grown in the presence of cherry and pomegranate leaf extracts to enhance the colloidal stability and make it suitable for nucleic acid delivery under the guidance of magnetic fields. This approach allowed the obtention of FeHA suspension with increased negative zeta potential leading to very good stability. In addition, the functionalization with natural extracts conferred antioxidant properties also favoring the maintenance of the Fe(III)/Fe(II) ratio in the apatitic structure, inducing the superparamagnetic properties. To evaluate the delivery capability of the system, a model GAPDH-targeting siRNA molecule was employed. Its interaction with the nanoplatform was characterized by assessing loading capacity and release kinetics, which were further interpreted using mathematical modeling to elucidate the underlying release mechanisms.

The present work investigates the rheological behavior of ceramic slurries made of hydroxyapatite powders doped with magnesium and strontium ions and selected as particularly relevant for biomedical applications. The incorporation of doping ions into the apatite crystal structure is a well-known way to enhance the bioactivity of hydroxyapatite through compositional and structural changes, however, this also affects the rheological properties relevant to the fabrication of ceramic devices by forming techniques based on the manipulation of aqueous slurries. We analyzed the effect of different apatitic chemical compositions, powder content, and dispersant amount on the shear behavior and flowability of slurries, thus finding that the structural changes in hydroxyapatite induced by ion doping significantly affected the colloidal stability of the apatite powders and the viscoelasticity of the slurries. This leads to improved rheological behavior in the hydroxyapatite suspensions, which is suitable for the future development of ceramic slurries, particularly for achieving novel ceramic devices by extrusion-based techniques.

Breast cancer (BC) frequently metastasizes to bone, leading to poor patient prognosis. The infiltration of cancer cells in bone impairs its homeostasis, triggering a pathological interaction between tumors and resident cells. Preclinical models able to mimic the bone microenvironment are needed to advance translational findings on BC mechanisms and treatments. We designed strontium-doped calcium phosphate cement to be employed for culturing cancer and bone cells and developed an in vitro bone metastasis model. The platform was established step by step, starting with the monoculture of cancer cells, mature osteoblasts (OBs) differentiated from mesenchymal stem cells, and mature osteoclasts (OCs) differentiated from Peripheral Blood Mononuclear Cells. The model was implemented with the co-culture of cancer cells with OBs or OCs, or the co-culture of OBs and OCs, allowing us to discriminate the interaction between the actors of the bone metastatic niche. The biomimetic material was further challenged with bone metastasis patient-derived material, showing good versatility and biocompatibility, suggesting its potential use as bone substitute. Overall, we developed a bone-mimicking model able to reproduce reciprocal interactions between cancer and bone cells in a biomimetic environment suitable for studying the biomolecular determinants of bone metastasis and, in the future, as a drug efficacy platform.

In the orthopedics field, scientists are continuing to research scaffolds to be used as bone implants [1] capable on one side to guide and sustain the natural metabolism of cells towards tissue regrowth and on the other to confer antibacterial properties to face post-surgical infections. The aim of this study is to test the anti-adhesive efficacy of two different commercially available calcium phosphate bone substitutes. Hydroxyapatite-tricalcium phosphate bone substitutes were prepared from Rattan wood pieces following the procedure described in [2] and doped with Mg and Sr. A biphasic commercial scaffold was used as a comparison. The gamma sterilized scaffolds were characterized in terms of morphological and topographical properties [3] through scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. A texture analysis of surfaces was conducted through the Haralick computer-based approach. The anti-adhesive properties of the surfaces were investigated using planktonic cultures of bacterial strains commonly found in bone infections, specifically a gram-positive ( Staphylococcus aureus ) and a gram-negative strain ( Escherichia coli ), in a time-dependent manner. Microscopy analyses (SEM) were performed on bacterial adhesion. The analyses of surfaces in terms of texture and topography demonstrated significant differences among the scaffolds. Preliminary results on bacterial adhesion exhibited a substantial reduction in the adhesion of both bacterial strains on the wood derived scaffolds. The obtained data demonstrated a difference in roughness and texture among all the scaffolds in terms of topography and morphology. Preliminary microbiological results indicated a reduced adhesion on surfaces of wood-derived scaffolds, especially at early time points. This finding suggests a correlation between surface properties, doping ions and bacterial adhesion behavior. The reduced adhesion at early time points could slow down biofilm formation and potentially enhance the effectiveness of antimicrobial treatments. Further microbiological and in vivo studies will be conducted to confirm the anti-adhesive properties of the scaffold.

Il cromosoma 2 umano si è formato all’incirca 1 milione di anni fa, dalla fusione telomerica dei due bracci corti degli autosomi omologhi presenti nelle grandi scimmie e nel progenitore comune ad esse e a Homo sapiens. Dando origine a una struttura bicentromerica, il cromosoma 2 manifesta instabilità alla segregazione/ricombinazione del DNA, da cui deriva aumento nel rischio mutazionale. Evidenze storiche di disordini osteometabolici e di massa adiposa derivati da queste mutazioni sono rintracciabili dal primo millennio a.C. al XXI secolo, suggerendo che questo cromosoma contribuisce alla stabilità evolutiva e individuale delle masse somatiche (free fat mass e fat mass) umane, insieme ad altri autosomi, come 15, 21 e 22, che producono sindromi genetiche dismetaboliche storicamente note. Complessivamente, nell’ultimo milione di anni circa gli intervalli di locus genico 2q31-37 e 2p13-25 avrebbero assicurato il mantenimento del programma evolutivo di sviluppo corporeo in Homo sapiens, confermando che sul cromosoma 2 risiede un controllo fondamentale per la speciazione dell’Uomo moderno.

BackgroundIn an era of precision and stratified medicine, homogeneity in population-based cohorts, stringent causative entry, and pattern analysis of datasets are key elements to investigate medical treatments. Adhering to these principles, we collected in vivo and in vitro data pointing to an insulin-sensitizing/insulin-mimetic effect of myo-inositol (MYO) relevant to cell regeneration in dentistry and oral surgery. Confirmation of this possibility was obtained by in silico analysis of the relation between in vivo and in vitro results (the so-called bed-to-benchside reverse translational approach).ResultsFourteen subjects over the 266 screened were young adult, normal weight, euglycemic, sedentary males having normal appetite, free diet, with a regular three-times-a-day eating schedule, standard dental hygiene, and negligible malocclusion/enamel defects. Occlusal caries were detected by fluorescence videoscanning, whereas body composition and energy balance were estimated with plicometry, predictive equations, and handgrip. Statistically significant correlations (Pearson r coefficient) were found between the number of occlusal caries and anthropometric indexes predicting insulin resistance (IR) in relation to the abdominal/visceral fat mass, fat-free mass, muscular strength, and energy expenditure adjusted to the fat and muscle stores. This indicated a role for IR in affecting dentin reparative processes. Consistently, in vitro administration of MYO to HUVEC and Swiss NIH3T3 cells in concentrations corresponding to those administered in vivo to reduce IR resulted in statistically significant cell replication (ANOVA/Turkey tests), suggesting that MYO has the potential to counteract inhibitory effects of IR on dental vascular and stromal cells turnover. Finally, in in silico experiments, quantitative evaluation (WOE and information value) of a bioinformatic Clinical Outcome Pathway confirmed that in vitro trophic effects of MYO could be transferred in vivo with high predictability, providing robust credence of its efficacy for oral health.ConclusionOur reverse bed-to-benchside data indicate that MYO might antagonize the detrimental effects of IR on tooth decay. This provides feasibility for clinical studies on MYO as a regenerative factor in dentistry and oral surgery, including dysmetabolic/aging conditions, bone reconstruction in oral destructive/necrotic disorders, dental implants, and for empowering the efficacy of a number of tissue engineering methodologies in dentistry and oral surgery.

This review focuses on the latest advancements in magnetic hydroxyapatite (mHA) nanoparticles and their potential applications in nanomedicine and regenerative medicine. mHA nanoparticles have gained significant interest over the last few years for their great potential, offering advanced multi-therapeutic strategies because of their biocompatibility, bioactivity, and unique physicochemical features, enabling on-demand activation and control. The most relevant synthetic methods to obtain magnetic apatite-based materials, either in the form of iron-doped HA nanoparticles showing intrinsic magnetic properties or composite/hybrid compounds between HA and superparamagnetic metal oxide nanoparticles, are described as highlighting structure–property correlations. Following this, this review discusses the application of various magnetic hydroxyapatite nanomaterials in bone regeneration and nanomedicine. Finally, novel perspectives are investigated with respect to the ability of mHA nanoparticles to improve nanocarriers with homogeneous structures to promote multifunctional biological applications, such as cell stimulation and instruction, antimicrobial activity, and drug release with on-demand triggering.

Osteosarcoma (OS) cancer treatments include systemic chemotherapy and surgical resection. In the last years, novel treatment approaches have been proposed, which employ a drug-delivery system to prevent offside effects and improves treatment efficacy. Locally delivering anticancer compounds improves on high local concentrations with more efficient tumour-killing effect, reduced drugs resistance and confined systemic effects. Here, the synthesis of injectable strontium-doped calcium phosphate (SrCPC) scaffold was proposed as drug delivery system to combine bone tissue regeneration and anticancer treatment by controlled release of methotrexate (MTX) and doxorubicin (DOX), coded as SrCPC-MTX and SrCPC-DOX, respectively. The drug-loaded cements were tested in an in vitro model of human OS cell line SAOS-2, engineered OS cell line (SAOS-2-eGFP) and U2-OS. The ability of doped scaffolds to induce OS cell death and apoptosis was assessed analysing cell proliferation and Caspase-3/7 activities, respectively. To determine if OS cells grown on doped-scaffolds change their migratory ability and invasiveness, a wound-healing assay was performed. In addition, the osteogenic potential of SrCPC material was evaluated using human adipose derived-mesenchymal stem cells. Osteogenic markers such as (i) the mineral matrix deposition was analysed by alizarin red staining; (ii) the osteocalcin (OCN) protein expression was investigated by enzyme-linked immunosorbent assay test, and (iii) the osteogenic process was studied by real-time polymerase chain reaction array. The delivery system induced cell-killing cytotoxic effects and apoptosis in OS cell lines up to Day 7. SrCPC demonstrates a good cytocompatibility and it induced upregulation of osteogenic genes involved in the skeletal development pathway, together with OCN protein expression and mineral matrix deposition. The proposed approach, based on the local, sustained release of anticancer drugs from nanostructured biomimetic drug-loaded cements is promising for future therapies aiming to combine bone regeneration and anticancer local therapy.

Nanocrystalline apatites have been intensively studied for decades, not only for their well-known mimesis of bone apatite but also for applicative purposes, whether as biomaterials for skeletal repair or more recently for a variety of nanomedical applications enabled by their peculiar surface characteristics. Particularly, ion-doped apatites are of great interest because the incorporation of foreign ions in the composition of apatite (nano)crystals alters the bulk and surface properties, modifying their ability to interact with the external environment. This is clearly seen in the physiology of bone tissue, whose mineral phase, a low crystallinity apatitic phase, can dynamically exchange ions with cells, thus driving bone metabolism. Taking bone mineral as a model, the present work describes the development of Mg-doped hydroxyapatite nanoparticles, exploiting hydrothermal synthesis to achieve extents of Mg2+ doping hardly achieved before and using citrate to develop stable apatite colloidal dispersions. Morphological and physicochemical analyses, associated with in-depth investigation of ions populating the apatitic lattice and the nonapatitic surface layer, concurred to demonstrate the cooperative presence of Mg2+ and citrate ions, affecting the dynamic ion retention/release mechanisms. Achieving high Mg2+ doping rates and understanding how Mg doping translates into surface activation of apatite-based nanoparticles is expected to foster the design of novel smart and tunable devices, to adsorb and release ionic species and cargo molecules, with potential innovations in the biomedical field or even beyond, as in catalysis or for environmental remediation.

The present study focuses on tailoring the relative content of Fe 3+ and Fe 2+ ions incorporation into hydroxyapatite (HA) lattice, employing a hydrothermal approach in a closed vessel to minimize Fe 2+ oxidation and secondary phase formation. Citrate molecules are used to regulate nanoparticle formation/stability, creating a mild reducing environment, while the impact of a stronger reducing agent, hydroxylamine, is explored. Fe 3+ insertion was found to be less favoured than Fe 2+ , possibly due to charge imbalance. Iron doping significantly alters stoichiometry and crystallinity of HA, with Fe 3+ enhancing OH - depletion. Morphological analysis reveals differences among samples, as induced by the different Fe ions incorporation: particularly Fe 2+ ion incorporation is found to maintain rod -like structures, which changes upon Fe 3+ presence. Overall, this study provides insights into controlled doping of HA with iron ions, vital for developing stable, redox-responsive nanomaterials applicable in cancer therapy and other applications where surface activity plays a relevant role.