In Vitro and in Vivo Mechanism of Bone Tumor Inhibition by Selenium-Doped Bone Mineral Nanoparticles

Overview of biodegradable materials for bone repair and osteosarcoma treatment: From bulk to scaffolds

Osteosarcoma, the most common type of malignant bone tumor that affects growing bones in teenagers and children, has become a significant challenge for medical science. The combination of chemotherapy and surgery has been the standard treatment strategy for decades. However, concerns about tumor recurrence and the toxic effects of the drugs continue to drive materials scientists to develop multifunctional scaffolds that can simultaneously support bone regeneration and prevent tumor recurrence. Emergent multifunctional scaffolds have the potential to foster essential and dynamic cellular communication, which can directly target, signal, stimulate, and enhance the body's natural bone repair response. This review emphasizes the mechanisms involved and highlights various technologies and manufacturing processes that align with the capability of these scaffolds to effectively promote bone repair, especially in the presence of osteosarcoma. Additionally, the review summarizes the current state of knowledge regarding scaffolds based on magnesium (Mg), zinc (Zn), and iron (Fe), as well as the antitumor properties of their corrosion products. The review also discusses the therapeutic potential of Mg-, Zn-, and Fe-based materials in inhibiting osteosarcoma cell proliferation. The article elaborates on the main research challenges and prospects of biodegradable materials for bone repair and osteosarcoma treatment.

Paclitaxel-Ang-2-functionalized bionic mesoporous selenium nanoparticles for targeted therapy of glioma

Glioma, the most prevalent primary intracranial tumor, presents significant clinical treatment challenges due to its high invasiveness and therapeutic resistance. Therefore, the development of a targeted therapeutic agent that is both highly effective and low in toxicity is crucial. In this research, we aimed to design a bionic mesoporous selenium nanoparticle (ACMLMSeP) functionalized with paclitaxel and Ang-2 for nasal administration as a targeted treatment approach for glioma. Nasal administration facilitates direct delivery of drugs to the brain through the olfactory nerve, thereby circumventing the protective mechanisms of the blood-brain barrier. Mesoporous selenium (MSe) significantly enhances the loading capacity for insoluble drugs while improving their water solubility. The functionalization of MSe enables slow drug release and facilitates targeted drug accumulation. Moreover, accumulated nano-selenium promotes reactive oxygen species (ROS) production, induces autophagy, and synergizes with drugs to accelerate apoptosis in tumor cells. Analysis using Transmission Electron Microscopy (TEM) images and Dynamic Light Scattering (DLS) indicated that ACMLMSe has an average particle size of roughly 135 nm. Results from in vitro release assessments indicated that the ACMLMSeP sustained the release of the drug, reaching a total release rate of 74.96 ± 2.34 % within 24 h. Cellular uptake studies and in vivo imaging showed the strong targeting capabilities of the ACMLMSeP nanoparticles. Furthermore, the results obtained from the MTT assays, flow cytometry analysis, immunofluorescence staining, and in vivo antitumor evaluations collectively revealed that ACMLMSeP effectively inhibited proliferation while promoting apoptosis in C6 cells. In summary, these experimental findings clearly suggest that ACMLMSeP may serve as a promising biomimetic nanosystem for the targeted treatment of brain glioma.

A 10-year bibliometric analysis in the field of osteosarcoma treatment from 2014 to 2023

OBJECTIVE

This paper aims to explore the research hot spot and development trend in osteosarcoma treatment using a bibliometric method based upon Web of Science Core Collection (WoSCC) platform over the last decade.

METHODS

The literature related to osteosarcoma and cure which were published from January 2014 to December 2023 were retrieved from the database of WoSCC and made an overall analysis for the papers published including number of articles, distribution of countries and institutions, author information, and keywords, with the CiteSpace 6.2.R5.

RESULTS

A total of 3131 papers were retrieved, including 2601 articles and 530 reviews, and the number of papers published has been increasing year by year in the last decade. There were 415 countries and 10,719 research institutions participating into the study. China's output of literature was the highest relying on its 1490 papers published, followed by The United States (548 papers). Shanghai Jiaotong university had the largest number of papers published (121 papers) and Central South University ranked second (82 papers). A total of 16,816 authors participated in the study. The number of the paper published by Massimo Serra of the Rizzoli Orthopaedics Institute was the largest (27 papers), followed by Dominique Heymann of the University of Sheffield (20 papers). The visualization analysis of keywords by CiteSpace software showed that the drug resistance, drug delivery, tumor tissue engineering and gene expression have become hotspots in the field of osteosarcoma treatment. Drug resistance significantly limits the effectiveness of current cancer treatments. Drug delivery technology not only enhances the targeting and efficacy of drugs but also helps to overcome drug resistance. The stem cells, targeted therapy, and tumor microenvironment represent the new research trends. In particular, the tumor microenvironment plays a key role in tumor development, progression, and drug resistance, and it offers numerous potential therapeutic targets.

CONCLUSION

Our investigation has identified key research foci and hotspots in osteosarcoma treatment, including drug resistance mechanisms, innovations in drug delivery technology, stem cell development, tumor microenvironment analysis, the development of novel therapies, and the clinical translation of tumor tissue engineering.

ROS-mediated Therapeutics Combined with Metal-based Porphyrin Nanoparticles and their Applications in Tumor Treatment

High concentrations of reactive oxygen species (ROS) can disrupt cell structure and induce apoptosis and necrosis of tumor cells. Photodynamic therapy (PDT) and chemodynamic therapy (CDT) are two cancer treatments mediated by reactive oxygen species. Oxygen molecules (O2) are one of the indispensable factors in PDT and hypoxic tumor sites limit its application. However, another ROS-mediated method, CDT, can generate •OH and O2in situ by Fenton reaction or Fenton-like reaction. Synergistic PDT/CDT therapy is a strategy to overcome the limitations of tumor microenvironment therapy. In this review, PDT and CDT therapies are briefly introduced, with an emphasis on metal-basrd porphyrin nanoparticles constructed in different ways for PDT/CDT dual-mode therapy. By introducing the history and latest design schemes of the treatment model, it provides ideas for researchers engaged in ROS-mediated cancer therapies.

Study on porous coral scaffolds containing a hydroxyapatite layer doped with selenium and their properties

The repair of bone defects caused by osteosarcoma is still a significant clinical issue, and new scaffolds need to be developed to solve this problem. The ocean is a treasure trove for developing new biomedical materials, and coral is widely thought to be suitable as a scaffold for bone implant materials due to its porous structure and mechanical properties. Selenium is known for its antioxidant and antitumor effects, inducing tumor cell cycle arrest. In this study, we hydrothermally transformed corals to grow a hydroxyapatite layer on the scaffold surface (CHAp) and combined it with selenium to obtain selenium-doped scaffolds (Se-CHAp) without affecting the porous structure of the coral. The research successfully validates their biocompatibility and the antitumor efficacy against 143B osteosarcoma cells. The results indicate that the Se-CHAp scaffolds yielded an obvious inhibitory effect on the proliferation of osteosarcoma cells, highlighting that they have huge prospects for application in biomedical technology.

Calcium Phosphate Loaded with Curcumin Prodrug and Selenium Is Bifunctional in Osteosarcoma Treatments

Although SeO32- ions have been loaded onto calcium phosphate to treat a wide range of cancers, the quest to promote bone tissue regeneration is still ongoing. Curcumin (cur), an herbal extraction, can selectively inhibit tumor cells and promote osteogenesis. In this study, SeO32- ions were co-precipitated in biomimetic calcium phosphate (Se@BioCaP), and modified curcumin prodrug (mcur) was adsorbed on diverse Se@BioCaP surfaces (mcur-Se@BioCaP-Ads). Co-precipitation yielded Se@BioCaP with a significantly higher Se content and exhibited a tailorable micro-/nanostructure. The favorable pH-responsive release of Se and mcur from mcur-Se@BioCaP-Ads showed a synergistic anticancer efficiency in OS cells, enhancing OS cell inhibition more than a single dose of them, which might be associated with ROS production in OS cells. In addition, increased alkaline phosphatase activity and calcium nodule formation in MC3T3-E1 pre-osteoblasts were also verified. These results suggest this novel mcur-Se@BioCaP-Ads has promising and widespread potential in OS treatments.

A biodegradable Fe-0.6Se alloy with superior strength and effective antibacterial and antitumor capabilities for orthopedic applications

Iron-selenium (Fe-Se) alloys have potential as attractive biodegradable bone-implant materials, given the antitumor properties of Se in cancer prevention and therapy. However, the fabrication of Fe-Se alloys is challenging due to the volatility of elemental Se and the significantly different melting points of Se and Fe. In this study, we successfully fabricated Fe-xSe (x = 0.2, 0.4, 0.6, 0.8, and 1 wt.%) alloys using suction casting, with FeSe compounds as the Se source. The microstructures, tensile properties, corrosion behavior, biocompatibility, antibacterial ability, and antitumor properties of the Fe-Se alloys were evaluated. The microstructures of the Fe-Se alloys were composed of α-Fe and FeSe phases. Among the Fe-Se alloys, Fe-0.6Se showed the best combination of tensile properties, with a yield strength of 1096.5 ± 7.2 MPa, an ultimate tensile strength of 1271.6 ± 6.3 MPa, and a fracture strain of 15.6 ± 3.3 %, and a degradation rate of 56.9 ± 0.4 μm/year. Moreover, the Fe-0.6Se alloy showed superb antibacterial ability against S. aureus, antitumor activity against 143B osteosarcoma cells, and osteogenicity and biocompatibility toward pre-osteoblast MC3T3-E1 cells. In summary, adding 0.2-1.0 wt.% Se to Fe does not affect the growth of healthy cells but effectively inhibits the growth and reproduction of tumor cells, and the Fe-0.6Se alloy is promising for orthopedic applications owing to its unique combination of mechanical and biofunctional properties. STATEMENT OF SIGNIFICANCE: This work reports on Fe-xSe (x = 0.2, 0.4, 0.6, 0.8, and 1 wt.%) alloys fabricated using suction casting. The microstructures of the Fe-Se alloys were composed of α-Fe and FeSe phases. Among the Fe-Se alloys, the Fe-0.6Se showed the best combination of tensile properties, with a yield strength of 1058.6 ± 3.9 MPa, an ultimate tensile strength of 1134.1 ± 2.9 MPa, and a fracture strain of 16.8 ± 1.5 %, and a degradation rate of 56.9 ± 0.4 μm/year. Moreover, the Fe-0.6Se alloy showed superb antibacterial ability against S. aureus, antitumor activity against 143B osteosarcoma cells, and significant osteogenic ability and biocompatibility toward pre-osteoblast MC3T3-E1 cells. In summary, the Fe-0.6Se alloy is promising for orthopedic applications owing to its unique combination of mechanical and biofunctional properties.

Se-incorporated polycaprolactone spherical polyhedron enhanced vitamin B2 loading and prolonged release for potential application in proliferative skin disorders

Development of novel drug vehicles for vitamin B2 (VitB2) delivery is very important for designing controllable release system to improve epidermal growth and bone metabolism. In this work, selenium (Se)-incorporated polycaprolactone (PCL) spherical polyhedrons are successfully synthesized via a single emulsion solvent evaporation method which is utilized to load VitB2 to fabricate cell-responsive Se-PCL@VitB2 delivery systems. Their physicochemical properties are characterized by DLS, SEM, XRD, FTIR, and TGA-DSC. The release kinetics of VitB2 or Se from the samples are investigated in PBS solution (pH = 2.0, 5.0, 7.4, 8.0 and 12.0). The cytocompatibilities are also evaluated with normal BMSC and epidermal HaCat cells. Results exhibit that Se-PCL@VitB2 particles presents spherical polyhedral morphology (approximately (3.25 ± 0.46) μm), negative surface charge (-(54.03 ± 2.94) mV), reduced crystallinity and good degradability. Stability experiments imply that both VitB2 and Se might be uniformly dispersed in PCL matrix. And the incorporation of Se facilely promotes the loading of VitB2. The encapsulation efficiency and loading capacity are (98.42 ± 1.06)% and (76.25 ± 1.27) for Se-PCL@VitB2 sample. Importantly, it exhibits more prolonged release of both VitB2 and Se in neutral PBS solution (pH = 7.4) than other pH conditions. Presumably, the electrostatic interaction between Se, VitB2 and PCL contribute to its release mode. Cell experiments show that Se-PCL@VitB2 presents strong cytotoxicity to HaCat cells mainly due to the cytotoxic effect of Se anions and PCL degradation products. However, it exhibits weak inhibitory effect on BMSC cells. These note that the synthesized Se-PCL@VitB2 particles can be promising drug vehicles for potential application in epidermal proliferative disorders.

Extracellular Matrix-Surrogate Advanced Functional Composite Biomaterials for Tissue Repair and Regeneration

Native tissues, comprising multiple cell types and extracellular matrix components, are inherently composites. Mimicking the intricate structure, functionality, and dynamic properties of native composite tissues represents a significant frontier in biomaterials science and tissue engineering research. Biomimetic composite biomaterials combine the benefits of different components, such as polymers, ceramics, metals, and biomolecules, to create tissue-template materials that closely simulate the structure and functionality of native tissues. While the design of composite biomaterials and their in vitro testing are frequently reviewed, there is a considerable gap in whole animal studies that provides insight into the progress toward clinical translation. Herein, we provide an insightful critical review of advanced composite biomaterials applicable in several tissues. The incorporation of bioactive cues and signaling molecules into composite biomaterials to mimic the native microenvironment is discussed. Strategies for the spatiotemporal release of growth factors, cytokines, and extracellular matrix proteins are elucidated, highlighting their role in guiding cellular behavior, promoting tissue regeneration, and modulating immune responses. Advanced composite biomaterials design challenges, such as achieving optimal mechanical properties, improving long-term stability, and integrating multifunctionality into composite biomaterials and future directions, are discussed. We believe that this manuscript provides the reader with a timely perspective on composite biomaterials.

Oxidative stress modulating nanomaterials and their biochemical roles in nanomedicine

Many pathological conditions are predominantly associated with oxidative stress, arising from reactive oxygen species (ROS); therefore, the modulation of redox activities has been a key strategy to restore normal tissue functions. Current approaches involve establishing a favorable cellular redox environment through the administration of therapeutic drugs and redox-active nanomaterials (RANs). In particular, RANs not only provide a stable and reliable means of therapeutic delivery but also possess the capacity to finely tune various interconnected components, including radicals, enzymes, proteins, transcription factors, and metabolites. Here, we discuss the roles that engineered RANs play in a spectrum of pathological conditions, such as cancer, neurodegenerative diseases, infections, and inflammation. We visualize the dual functions of RANs as both generator and scavenger of ROS, emphasizing their profound impact on diverse cellular functions. The focus of this review is solely on inorganic redox-active nanomaterials (inorganic RANs). Additionally, we deliberate on the challenges associated with current RANs-based approaches and propose potential research directions for their future clinical translation.

Facile fabrication of linezolid/strontium coated hydroxyapatite/graphene oxide nanocomposite for osteoporotic bone defect

Hydroxyapatite (HAp) coatings currently have limited therapeutic applications because they lack anti-infection, osteoinductivity, and poor mechanical characteristics. On the titanium substrate, electrochemical deposition (ECD) was used to construct the strontium (Sr)-featuring hydroxyapatite (HAp)/graphene oxides (GO)/linezolid (LZ) nanomaterial coated with antibacterial and drug delivery properties. The newly fabricated nanomaterials were confirmed by X-ray diffraction analysis (XRD), Fourier-transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) analysis and morphological features were examined by scanning electron microscope (SEM) analysis. The results reveal multiple nucleation sites for SrHAp/GO/LZ composite coatings due to oxygen-comprising moieties on the 2D surface of GO. It was shown to be favorable for osteoblast proliferation and differentiation. The elastic modulus and hardness of LZ nanocomposite with SrHAp/GO/LZ coatings were increased by 67 % and 121 %, respectively. An initial 5 h burst of LZ release from the SrHAp/GO/LZ coating was followed by 14 h of gradual release, owing to LZ's physical and chemical adsorption. The SrHAp/GO/LZ coating effectively inhibited both S. epidermidis and S. aureus, and the inhibition lasted for three days, as demonstrated by the inhibition zone and colony count assays. When MG-63 cells are coated with SrHAp/GO/LZ composite coating, their adhesion, proliferation, and differentiation greatly improve when coated with pure titanium. A novel surface engineering nanomaterial for treating and preventing osteoporotic bone defects, SrHAp/GO/LZ, was shown to have high mechanical characteristics, superior antibacterial abilities, and osteoinductivity.

Enhancing osteoblast proliferation and bone regeneration by poly (amino acid)/selenium-doped hydroxyapatite

Among various biomaterials employed for bone repair, composites with good biocompatibility and osteogenic ability had received increasing attention from biomedical applications. In this study, we doped selenium (Se) into hydroxyapatite (Se-HA) by the precipitation method, and prepared different amounts of Se-HA-loaded poly (amino acid)/Se-HA (PAA/Se-HA) composites (0, 10 wt%, 20 wt%, 30 wt%) byin-situmelting polycondensation. The physical and chemical properties of PAA/Se-HA composites were characterized by x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and their mechanical properties. XRD and FT-IR results showed that PAA/Se-HA composites contained characteristic peaks of PAA and Se-HA with amide linkage and HA structures. DSC and TGA results specified the PAA/Se-HA30 composite crystallization, melting, and maximum weight loss temperatures at 203.33 °C, 162.54 °C, and 468.92 °C, respectively, which implied good thermal stability. SEM results showed that Se-HA was uniformly dispersed in PAA. The mechanical properties of PAA/Se-HA30 composites included bending, compressive, and yield strengths at 83.07 ± 0.57, 106.56 ± 0.46, and 99.17 ± 1.11 MPa, respectively. The cellular responses of PAA/Se-HA compositesin vitrowere studied using bone marrow mesenchymal stem cells (BMSCs) by cell counting kit-8 assay, and results showed that PAA/Se-HA30 composites significantly promoted the proliferation of BMSCs at the concentration of 2 mg ml-1. The alkaline phosphatase activity (ALP) and alizarin red staining results showed that the introduction of Se-HA into PAA enhanced ALP activity and formation of calcium nodule. Western blotting and Real-time polymerase chain reaction results showed that the introduction of Se-HA into PAA could promoted the expression of osteogenic-related proteins and mRNA (integrin-binding sialoprotein, osteopontin, runt-related transcription factor 2 and Osterix) in BMSCs. A muscle defect at the back and a bone defect at the femoral condyle of New Zealand white rabbits were introduced for evaluating the enhancement of bone regeneration of PAA and PAA/Se-HA30 composites. The implantation of muscle tissue revealed good biocompatibility of PAA and PAA/Se-HA30 composites. The implantation of bone defect showed that PAA/Se-HA30 composites enhanced bone formation at the defect site (8 weeks), exhibiting good bone conductivity. Therefore, the PAA-based composite was a promising candidate material for bone tissue regeneration.

Recent advances and biomedical application of 3D printed nanocellulose-based adhesive hydrogels: A review

Nanocellulose-based tissue adhesives show promise for achieving rapid hemostasis and effective wound healing. Conventional methods, such as sutures and staples, have limitations, prompting the exploration of bioadhesives for direct wound adhesion and minimal tissue damage. Nanocellulose, a hydrolysis product of cellulose, exhibits superior biocompatibility and multifunctional properties, gaining interest as a base material for bioadhesive development. This study explores the potential of nanocellulose-based adhesives for hemostasis and wound healing using 3D printing techniques. Nanocellulose enables the creation of biodegradable adhesives with minimal adverse effects and opens avenues for advanced wound healing and complex tissue regeneration, such as skin, blood vessels, lungs, cartilage, and muscle. This study reviews recent trends in various nanocellulose-based 3D printed hydrogel patches for tissue engineering applications. The review also introduces various types of nanocellulose and their synthesis, surface modification, and bioadhesive fabrication techniques via 3D printing for smart wound healing.

Nanoselenium attenuates renal ischemia-reperfusion injury in rats

Using selenium (Se) nanoparticles has received attention in recent years because of their therapeutic benefits due to their anticancer, antioxidant, anti-inflammatory, and anti-diabetic effects. This research was conducted to evaluate the possible protective impact of nano-Se on renal unilateral ischemia/reperfusion injury (uIRI) in adult male Wistar rats. Using clamping of the left renal pedicle within 45 min uIRI was induced. The animals were randomly divided into nine groups of control, nano-Se (0.25, 0.5, and 1 mg/kg bw/day) alone, uIRI control, and uIRI rats administrated with nano-Se. At 30 days after treatment, the animals were sacrificed to be assessed biochemically and histopathologically. Nano-Se in uIRI groups have significantly decreased serum creatinine, urea levels, renal histological damage, and increased antioxidant status. Also, our findings demonstrated that the administration of nano-Se caused a significant decrease in the immunoreactivity level of the epidermal growth factor (EGF) and EGFR expression (EGF receptor) in the renal tissue of the uIRI rats. Therefore, nano-Se possesses renoprotective effects, and this effect might be attributable to its antioxidant and free radical scavenger effects. These renoprotective effects may depend on the decreased EGF immunoreactivity level and EGFR expression in the kidney tissue and improve the structure of the kidney tissue. Thus, our research provided biochemical and histological data supporting the potential clinical use of nano-Se for the treatment of certain kidney disorders.

Chitosan/NH2-MIL-125 (Ti) scaffold loaded with doxorubicin for postoperative bone tumor clearance and osteogenesis: An in vitro study

Surgical resection remains the primary treatment modality for bone tumors. However, it is prone to local bone defects and tumor recurrence. Therefore, there is an urgent need for multifunctional biomaterials that combine tumor treatment and bone repair after bone tumor surgery. Herein, a chitosan composite scaffold (CS/DOX@Ti-MOF) was designed for both tumor therapy and bone repair. Among them, the amino-functionalized Ti-based metal-organic framework (NH2-MIL-125 (Ti), Ti-MOF) has a high specific surface area of 1116 m2/g and excellent biocompatibility, and promotes osteogenic differentiation. The doxorubicin (DOX) loading capacity of Ti-MOF was 322 ± 21 mg/g, and DOX@Ti-MOF has perfect antitumor activity. Furthermore, the incorporation of DOX@Ti-MOF improved the physical and mechanical properties of the composite scaffolds, making the scaffold surface rough and favorable for cells to attach. CS/DOX@Ti-MOF retains the unique properties of each component. It responds to the release of DOX in the tumor microenvironment to remove residual tumor cells, followed by providing a site for cell attachment, proliferation, and differentiation. This promotes bone repair and achieves the sequential treatment of postoperative bone tumors. Overall, CS/DOX@Ti-MOF may be a promising substitute for postoperative bone tumor clearance and bone defect repair. It also provides a possible strategy for postoperative bone tumor treatment.

The effect of graphene and graphene oxide induced reactive oxygen species on polycaprolactone scaffolds for bone cancer applications

Bone cancer remains a critical healthcare problem. Among current clinical treatments, tumour resection is the most common strategy. It is usually effective but may present several limitations such as multiple operations, long hospital time, and the potential recurrence caused by the incomplete removal of cancer cells. To address these limitations, three-dimensional (3D) scaffolds fabricated through additive manufacturing have been researched for both bone cancer treatment and post-treatment rehabilitation. Polycaprolactone (PCL)-based scaffolds play an important role in bone regeneration, serving as a physical substrate to fill the defect site, recruiting cells, and promoting cell proliferation and differentiation, ultimately leading to the regeneration of the bone tissue without multiple surgical applications. Multiple advanced materials have been incorporated during the fabrication process to improve certain functions and/or modulate biological performances. Graphene-based nanomaterials, particularly graphene (G) and graphene oxide (GO), have been investigated both in vitro and in vivo, significantly improving the scaffold's physical, chemical, and biological properties, which strongly depend on the material type and concentration. A unique targeted inhibition effect on cancer cells was also discovered. However, limited research has been conducted on utilising graphene-based nanomaterials for both bone regeneration and bone cancer treatment, and there is no systematic study into the material- and dose-dependent effects, as well as the working mechanism on 3D scaffolds to realise these functions. This paper addresses these limitations by designing and fabricating PCL-based scaffolds containing different concentrations of G and GO and assessing their biological behaviour correlating it to the reactive oxygen species (ROS) release level. Results suggest that the ROS release from the scaffolds is a dominant mechanism that affects the biological behaviour of the scaffolds. ROS release also contributes to the inhibition effect on bone cancer due to healthy cells and cancer cells responding differently to ROS, and the osteogenesis results also present a certain correlation with ROS. These observations revealed a new route for realising bone cancer treatment and subsequent new bone regeneration, using a single dual-functional 3D scaffold.

3D-printed tri-element-doped hydroxyapatite/ polycaprolactone composite scaffolds with antibacterial potential for osteosarcoma therapy and bone regeneration

The resection of malignant osteosarcoma often results in large segmental bone defects, and the residual cells can facilitate recurrence. Consequently, the treatment of osteosarcoma is a major challenge in clinical practice. The ideal goal of treatment for osteosarcoma is to eliminate it thoroughly, and repair the resultant bone defects as well as avoid bacterial infections. Herein, we fabricated a selenium/strontium/zinc-doped hydroxyapatite (Se/Sr/Zn-HA) powder by hydrothermal method, and then employed it with polycaprolactone (PCL) as ink to construct composite scaffolds through 3D printing, and finally introduced them in bone defect repair induced by malignant osteosarcoma. The resultant composite scaffolds integrated multiple functions involving anti-tumor, osteogenic, and antibacterial potentials, mainly attributed to the anti-tumor effects of SeO32-, osteogenic effects of Sr2+ and Zn2+, and antibacterial effects of SeO32- and Zn2+. In vitro studies confirmed that Se/Sr/Zn-HA leaching solution could induce apoptosis of osteosarcoma cells, differentiation of MSCs, and proliferation of MC3T3-E1 while showing excellent antibacterial properties. In vivo tests demonstrated that Se/Sr/Zn-HA could significantly suppress tumors after 8 days of injection, and the Se/Sr/Zn-HA-PCLs scaffold repaired femoral defects effectively after 3 months of implantation. Summarily, the Se/Sr/Zn-HA-PCLs composite scaffolds developed in this study were effective for tumor treatment, bone defect repair, and post-operative anti-infection, which provided a great potential to be a facile therapeutic material for osteosarcoma resection.

New strategies for evaluating imidacloprid-induced biological consequences targeted to Eisenia fetida species and the corresponding mechanisms of its toxicity

Imidacloprid (IMI), a neonicotinoid insecticide, has a wide variety of applications in both agriculture and horticulture. As a result of it massive and repeated use, its traces remained in soil pose severe damage to soil invertebrates, particularly earthworms. Limited information is available regarding the underlying mechanisms of IMI toxicity toward earthworms at the molecular, transcriptional, and cellular levels. Here, Eisenia fetida coelomocytes and key defensive proteins were selected as targeted receptors to explore the toxic mechanisms of oxidative stress-mediated cytotoxicity, genotoxicity, and antioxidant responses induced by IMI stress and the molecular mechanisms underlying the binding of IMI and superoxide dismutase (SOD)/catalase (CAT). Results showed that IMI exposure destroyed the cell membrane integrity of earthworm cells, causing cell damage and cytotoxicity. The intracellular levels of ROS, including ·O2- and H2O2 were induced by IMI exposure, thereby triggering oxidative stress and damage. Moreover, IMI exposure attenuated the antioxidative stress responses (reduced antioxidant capacity and CAT/SOD activities) and caused deleterious effects (enhanced DNA damage, lipid peroxidation (LPO), and protein carbonylation (PCO)) through ROS-mediated oxidative stress pathway. Aberrant gene expression associated with oxidative stress and defense regulation, including CAT, CRT, MT, SOD, GST, and Hsp70 were induced after IMI exposure. Concentration-dependent conformational and structural alterations of CAT/SOD were observed when IMI binding. Also, direct binding of IMI resulted in significant inhibition of CAT/SOD activities in vitro. Molecular simulation showed that IMI preferred to bind to CAT active center through its direct binding with the key residue Tyr 357, while IMI bound more easily to the connecting cavity of two subunits away from SOD active center. In addition, hydrogen bonds and hydrophobic force are the main driving force of IMI binding with CAT/SOD. These findings have implications for comprehensive evaluation of IMI toxicity to soil eco-safety and offer novel strategies to elucidate the toxic mechanisms and pathways of IMI stress.

IOX1 epigenetically enhanced photothermal therapy of 3D-printing silicene scaffolds against osteosarcoma with favorable bone regeneration

Osteosarcoma (OS) is the third most common malignancy in adolescence. Currently, the treatments of OS confront great obstacles of tumor recurrence and critical bone defects after surgery, severely affecting the survival rates and living qualities of patients. Hence, it is urged to develop distinct biomaterials with both efficient tumor therapeutic and osteogenic functions. Although photothermal therapy (PTT) has aroused expanding interest, characterizing negligible invasiveness and high spatiotemporal adjustment, few studies discussed its drawbacks, such as thermal injury to adjacent normal tissue and exceeded laser power density, implying that focusing on sensitizing OS to PTT instead of simply elevating the laser power density may be a fresh way to enhance the PTT efficacy and attenuate the side/adverse effects. Herein, we successfully constructed 3D-printing silicene bioactive glass scaffolds with preferable PTT efficacy at the second near-infrared (NIR-II) biowindow and outstanding osteogenic biofunctions owing to the release of bioactive elements during degradation. Impressively, a histone demethylase inhibitor, IOX1, was introduced before PTT to sensitize OS to thermal therapy and minimize the side/adverse effects. This work offered a distinctive paradigm for optimizing the PTT efficacy of osteogenic scaffolds against OS with epigenetic modulation agents.

Aspect ratio-dependent dual-regulation of the tumor immune microenvironment against osteosarcoma by hydroxyapatite nanoparticles

Accumulating studies demonstrated that hydroxyapatite nanoparticles (HANPs) showed a selective anti-tumor effect, making them a good candidate for osteosarcoma (OS) treatment. However, the capacity of HANPs with different aspect ratios to regulate tumor immune microenvironment (TIM) was scarcely reported before. To explore it, the three HANPs with aspect ratios from 1.86 to 6.25 were prepared by wet chemical method. After a 24 or 72 h-exposure of OS UMR106 cells or macrophages to the nanoparticles, the tumor cells exhibited immunogenic cell death (ICD) indicated by the increased production of calreticulin (CRT), adenosine triphosphate (ATP) and high mobility group box 1 (HMGB1), and macrophages were activated with the release of pro-inflammatory cytokines. Next, the beneficial crosstalk between tumor cells and macrophages generated in the presence of HANPs for improved anti-tumor immunity activation. In the OS-bearing cognate rat model, HANPs inhibited OS growth, which was positively correlated with CRT and HMGB1 expression, and macrophage polarization in the tumor tissues. Additionally, HANPs promoted CD8+ T cell infiltration into the tumor and systemic dendritic cell maturation. Particularly, HANPs bearing the highest aspect ratio exhibited the strongest immunomodulatory and anti-tumor function. This study suggested the potential of HANPs to be a safe and effective drug-free nanomaterial to control the TIM for OS therapy. STATEMENT OF SIGNIFICANCE: Emerging studies demonstrated that hydroxyapatite nanoparticles (HANPs) inhibited tumor cell proliferation and tumor growth. However, the underlying anti-tumor mechanism still remains unclear, and the capacity of HANPs without any other additive to regulate tumor immune microenvironment (TIM) was scarcely reported before. Herein, we demonstrated that HANPs, in an aspect ratio-dependent manner, showed the potential to delay the growth of osteosarcoma (OS) and to regulate TIM by promoting the invasion of CD8+ T cells and F4/80+ macrophages, and inducing immunogenic cell death (ICD) in tumors. This work revealed the new molecular mechanism for HANPs against OS, and suggested HANPs might be a novel ICD inducer for OS treatment.

Functional anti-bone tumor biomaterial scaffold: construction and application

Bone tumors, including primary bone tumors and bone metastases, have been plagued by poor prognosis for decades. Although most tumor tissue is removed, clinicians are still confronted with the dilemma of eliminating residual cancer cells and regenerating defective bone tissue after surgery. Therefore, functional biomaterial scaffolds are considered to be the ideal candidates to bridge defective tissues and restrain cancer recurrence. Through functionalized structural modifications or coupled therapeutic agents, they provide sufficient mechanical strength and osteoinductive effects while eliminating cancer cells. Numerous novel approaches such as photodynamic, photothermal, drug-conjugated, and immune adjuvant-assisted therapies have exhibited remarkable efficacy against tumors while exhibiting low immunogenicity. This review summarizes the progress of research on biomaterial scaffolds based on different functionalization strategies in bone tumors. We also discuss the feasibility and advantages of the combined application of multiple functionalization strategies. Finally, potential obstacles to the clinical translation of anti-tumor bone bioscaffolds are highlighted. This review will provide valuable references for future advanced biomaterial scaffold design and clinical bone tumor therapy.

Nano selenium-doped TiO2 nanotube arrays on orthopedic implants for suppressing osteosarcoma growth

Osteosarcoma, the most common primary malignant bone tumor, is characterized by malignant cells producing osteoid or immature bone tissue. Most osteosarcoma patients require reconstructive surgery to restore the functional and structural integrity of the injured bone. Metal orthopedic implants are commonly used to restore the limb integrity in postoperative patients. However, conventional metal implants with a bioinert surface cannot inhibit the growth of any remaining cancer cells, resulting in a higher risk of cancer recurrence. Herein, we fabricate a selenium-doped TiO2 nanotube array (Se-doped TNA) film to modify the surface of medical pure titanium substrate, and evaluate the anti-tumor effect and biocompatibility of Se-doped TNA film. Moreover, we further explore the anti-tumor potential mechanism of Se-doped TNA film by studying the behaviors of human osteosarcoma cells in vitro. We provide a new pathway for achieving the anti-tumor function of orthopedic implants while keeping the biocompatibility, aiming to suppress the recurrence of osteosarcoma.

FePSe3 -Nanosheets-Integrated Cryogenic-3D-Printed Multifunctional Calcium Phosphate Scaffolds for Synergistic Therapy of Osteosarcoma

Clinical treatment of osteosarcoma encounters great challenges of postsurgical tumor recurrence and extensive bone defect. To develop an advanced artificial bone substitute that can achieve synergistic bone regeneration and tumor therapy for osteosarcoma treatment, a multifunctional calcium phosphate composite enabled by incorporation of bioactive FePSe3 -nanosheets within the cryogenic-3D-printed α-tricalcium phosphate scaffold (TCP-FePSe3 ) is explored. The TCP-FePSe3 scaffold exhibits remarkable tumor ablation ability due to the excellent NIR-II (1064 nm) photothermal property of FePSe3 -nanosheets. Moreover, the biodegradable TCP-FePSe3 scaffold can release selenium element to suppress tumor recurrence by activating of the caspase-dependent apoptosis pathway. In a subcutaneous tumor model, it is demonstrated that tumors can be efficiently eradicated via the combination treatment with local photothermal ablation and the antitumor effect of selenium element. Meanwhile, in a rat calvarial bone defect model, the superior angiogenesis and osteogenesis induced by TCP-FePSe3 scaffold have been observed in vivo. The TCP-FePSe3 scaffold possesses improved capability to promote the repair of bone defects via vascularized bone regeneration, which is induced by the bioactive ions of Fe, Ca, and P released during the biodegradation of the implanted scaffolds. The TCP-FePSe3 composite scaffolds fabricated by cryogenic-3D-printing illustrate a distinctive strategy to construct multifunctional platform for osteosarcoma treatment.

Multi-Anticancer Activities of Phytoestrogens in Human Osteosarcoma

Phytoestrogens are plant-derived bioactive compounds with estrogen-like properties. Their potential health benefits, especially in cancer prevention and treatment, have been a subject of considerable research in the past decade. Phytoestrogens exert their effects, at least in part, through interactions with estrogen receptors (ERs), mimicking or inhibiting the actions of natural estrogens. Recently, there has been growing interest in exploring the impact of phytoestrogens on osteosarcoma (OS), a type of bone malignancy that primarily affects children and young adults and is currently presenting limited treatment options. Considering the critical role of the estrogen/ERs axis in bone development and growth, the modulation of ERs has emerged as a highly promising approach in the treatment of OS. This review provides an extensive overview of current literature on the effects of phytoestrogens on human OS models. It delves into the multiple mechanisms through which these molecules regulate the cell cycle, apoptosis, and key pathways implicated in the growth and progression of OS, including ER signaling. Moreover, potential interactions between phytoestrogens and conventional chemotherapy agents commonly used in OS treatment will be examined. Understanding the impact of these compounds in OS holds great promise for developing novel therapeutic approaches that can augment current OS treatment modalities.

Translational Selenium Nanoparticles to Attenuate Allergic Dermatitis through Nrf2-Keap1-Driven Activation of Selenoproteins

Easy recurrence and strong treatment side effects significantly limit the clinical treatment of allergic dermatitis. The human trace element selenium (Se) plays essential roles in redox regulation through incorporation into selenoproteins in the form of 21st necessary amino acid selenocysteine, to participates in the pathogenesis and intervention of chronic inflammatory diseases. Therefore, based on the safe and elemental properties of Se, we construct a facile-synthesis strategy for antiallergic selenium nanoparticles (LET-SeNPs), and scale up the production by employing a spray drying method with lactose (Lac-LET-SeNPs) or maltodextrin (Mal-LET-SeNPs) as encapsulation agents realizing larger scale production and a longer storage time. As expected, these as-prepared LET-SeNPs could effectively activate the Nrf2-Keap1 signaling pathway to enhance the expression of antioxidative selenoprotein at mRNA and protein levels, then inhibit mast cell activation to achieve efficient antiallergic activity. Interestingly, LET-SeNPs undergo metabolism to seleno-amino acids to promote biosynthesis of selenoproteins, which could suppress ROS-induced cyclooxygenase-2 (COX-2) and MAPKs activation to suppress the release of histamine and inflammatory cytokines. Allergic mouse and Macaca fascicularis models further confirm that LET-SeNPs could increase the Se content and selenoprotein expression in the skin, decrease mast cells activation and inflammatory cells infiltration, and finally exhibit the high therapeutic effects on allergic dermatitis. Taken together, this study not only constructs facile large-scale synthesis of translational Se nanomedicine to break through the bottleneck problem of nanomaterials but also sheds light on its application in the intervention and treatment of allergies.

Hierarchically Structured Hydroxyapatite Particles Facilitate the Enhanced Integration and Selective Anti-Tumor Effects of Amphiphilic Prodrug for Osteosarcoma Therapy

Efficient delivery of cargo into target cells is a formidable challenge in modern medicine. Despite the great promise of biomimetic hydroxyapatite (HA) particles in tissue engineering, their potential applications in bone tumor therapy, particularly their structure-function relationships in cargo delivery to target cells, have not yet been well explored. In this study, biomimetic multifunctional composite microparticles (Bm-cMPs) are developed by integrating an amphiphilic prodrug of curcumin with hierarchically structured HA microspheres (Hs-hMPs). Then, the effects of the hierarchical structure of vehicles on the integration and delivery of cargo as well as the anti-osteosarcoma (OS) effect of the composite are determined. Different hierarchical structures of the vehicles strongly influence the self-assembly behavior of the prodrug. The flake-like crystals of Hs-hMPs enable the highest loading capacity and enhance the stability of the cargo. Compared to the normal cells, OS cells exhibit 3.56-times better uptake of flake-like Hs-hMPs, facilitating the selective anti-tumor effect of the prodrug. Moreover, Bm-cMPs suppress tumor growth and metastasis by promoting apoptosis and inhibiting cell proliferation and tumor vascularization. The findings shed light on the potential application of Bm-cMPs and suggest a feasible strategy for developing an effective targeted therapy platform using hierarchically structured minerals for OS treatment.

Selenium-incorporated mesoporous silica nanoparticles for osteosarcoma therapy

Selenium (Se) compounds are promising chemotherapeutics due to their ability to inhibit cancer cell activity via the generation of reactive oxygen species (ROS). However, to circumvent adverse effects on bone healthy cells, new methods are needed to allow intracellular Se delivery. Mesoporous silica nanoparticles (MSNs) are promising carriers for therapeutic ion delivery due to their biocompability, rapid uptake via endocytosis, and ability to efficiently incorporate ions within their tunable structure. With the aim of selectively inhibiting cancer cells, here we developed three types of MSNs and investigated their ability to deliver Se. Specifically, MSNs containing SeO32- loaded on the surface and in the pores (MSN-SeL), SeO32- doped in the silica matrix (Se-MSNs) and Se nanoparticles (SeNP) coated with mesoporous silica (SeNP-MSNs), were successfully synthesized. All synthesized nanoparticles were stable in neutral conditions but showed rapid Se release in the presence of glutathione (GSH) and nicotinamide adenine dinucleotide phosphate (NADPH). Furthermore, all nanoparticles were cytotoxic towards SaoS-2 cells and showed significantly lower toxicity towards healthy osteoblasts, where Se doped MSNs showed lowest toxicity towards osteoblasts. We further show that the nanoparticles could induce ROS and cell apoptosis. Here we demonstrate MSNs as promising Se delivery carriers for osteosarcoma (OS) therapy.

Advances in tumor nanotechnology: theragnostic implications in tumors via targeting regulated cell death

Cell death constitutes an indispensable part of the organismal balance in the human body. Generally, cell death includes regulated cell death (RCD) and accidental cell death (ACD), reflecting the intricately molecule-dependent process and the uncontrolled response, respectively. Furthermore, diverse RCD pathways correlate with multiple diseases, such as tumors and neurodegenerative diseases. Meanwhile, with the development of precision medicine, novel nano-based materials have gradually been applied in the clinical diagnosis and treatment of tumor patients. As the carrier, organic, inorganic, and biomimetic nanomaterials could facilitate the distribution, improve solubility and bioavailability, enhance biocompatibility and decrease the toxicity of drugs in the body, therefore, benefiting tumor patients with better survival outcomes and quality of life. In terms of the most studied cell death pathways, such as apoptosis, necroptosis, and pyroptosis, plenty of studies have explored specific types of nanomaterials targeting the molecules and signals in these pathways. However, no attempt was made to display diverse nanomaterials targeting different RCD pathways comprehensively. In this review, we elaborate on the potential mechanisms of RCD, including intrinsic and extrinsic apoptosis, necroptosis, ferroptosis, pyroptosis, autophagy-dependent cell death, and other cell death pathways together with corresponding nanomaterials. The thorough presentation of RCD pathways and diverse nano-based materials may provide a wider cellular and molecular landscape of tumor diagnosis and treatments.

Chemotherapy-Sensitized In Situ Vaccination for Malignant Osteosarcoma Enabled by Bioinspired Calcium Phosphonate Nanoagents

How to effectively treat malignant osteosarcoma remains clinically challenging. Programmed delivery of chemotherapeutic agents and immunostimulants may offer a universal strategy for killing osteosarcoma cells while simultaneously eliciting in situ antitumor immunity. However, targeted chemoimmunotherapy lacks a reliable delivery system. To address this issue, we herein developed a bioinspired calcium phosphonate nanoagent that was synthesized by chemical reactions between Ca²⁺ and phosphonate residue from zoledronic acid using bovine serum albumin as a scaffold. In addition, methotrexate combination with a phosphorothioate CpG immunomodulator was also loaded for pH-responsive delivery to enable synergistic chemoimmunotherapy of osteosarcoma. The calcium phosphonate nanoagents were found to effectively accumulate in osteosarcoma for nearly 1 week, which is favorable for exerting the vaccination effects in situ by maturing dendritic cells and priming CD8⁺ T cells to suppress the osteosarcoma progression and pulmonary metastasis through controlled release of the three loaded agents in the acidic tumor microenvironment. The current study may thus offer a reliable delivery platform for achieving targeted chemotherapy-induced in situ antitumor immunity.

Calcium phosphate bone cements as local drug delivery systems for bone cancer treatment

Bone cancer is usually a metastatic disease, affecting people of all ages. Its effective therapy requires a targeted drug administration locally at the cancer site so that the surrounding healthy organs and tissues stay unharmed. Upon a thorough literature search, a tremendous number of published articles are reporting on development of calcium phosphate cements (CPCs) for the treatment of a variety of diseases, such as osteoporosis, osteoarthritis, osteomyelitis, and other musculoskeletal disorders. However, just a limited number of research employs CPCs specifically for bone cancer treatment. In this review article, we study the factors influencing the local drug release from CPCs and particularly focus on bone cancer therapy. Finally, we locate the deficiencies in the literature regarding this specific topic and propose which other perspectives should be considered and discussed in future articles.

Synthetic biodegradable polymer materials in the repair of tumor-associated bone defects

The repair and reconstruction of bone defects and the inhibition of local tumor recurrence are two common problems in bone surgery. The rapid development of biomedicine, clinical medicine, and material science has promoted the research and development of synthetic degradable polymer anti-tumor bone repair materials. Compared with natural polymer materials, synthetic polymer materials have machinable mechanical properties, highly controllable degradation properties, and uniform structure, which has attracted more attention from researchers. In addition, adopting new technologies is an effective strategy for developing new bone repair materials. The application of nanotechnology, 3D printing technology, and genetic engineering technology is beneficial to modify the performance of materials. Photothermal therapy, magnetothermal therapy, and anti-tumor drug delivery may provide new directions for the research and development of anti-tumor bone repair materials. This review focuses on recent advances in synthetic biodegradable polymer bone repair materials and their antitumor properties.

Biomaterial-assisted tumor therapy: A brief review of hydroxyapatite nanoparticles and its composites used in bone tumors therapy

Malignant bone tumors can inflict significant damage to affected bones, leaving patients to contend with issues like residual tumor cells, bone defects, and bacterial infections post-surgery. However, hydroxyapatite nanoparticles (nHAp), the principal inorganic constituent of natural bone, possess numerous advantages such as high biocompatibility, bone conduction ability, and a large surface area. Moreover, nHAp's nanoscale particle size enables it to impede the growth of various tumor cells via diverse pathways. This article presents a comprehensive review of relevant literature spanning the past 2 decades concerning nHAp and bone tumors. The primary goal is to explore the mechanisms responsible for nHAp's ability to hinder tumor initiation and progression, as well as to investigate the potential of integrating other drugs and components for bone tumor diagnosis and treatment. Lastly, the article discusses future prospects for the development of hydroxyapatite materials as a promising modality for tumor therapy.

Selenium Nanoparticles Synergistically Stabilized by Starch Microgel and EGCG: Synthesis, Characterization, and Bioactivity

Selenium (Se) is a chemical element essential to human health because of its bioactive properties, including antioxidative, anticancer, and immunomodulating activities. Despite the high therapeutic potential of Se, its intrinsic properties of poor stability, a narrow therapeutic window, and low bioavailability and bioactivity have limited its clinical applications. Selenium nanoparticles (SeNPs) exhibit lower toxicity and higher bioactivity than other Se forms. Herein, we report a green method for the preparation of monodisperse SeNPs with starch microgel (SM) and epigallocatechin gallate (EGCG) through Se-O bonds and polysaccharide-polyphenol interactions (namely, SM-EGCG-SeNPs). SM-EGCG-SeNPs showed higher stability, bioactivities, and cytotoxicity than SeNPs and SM-SeNPs at the equivalent dose. SM-EGCG-SeNPs induced the apoptosis of cancer cells via the activation of several caspases and reactive oxygen species overproduction. This work proposes a facile method for the design and potentiation of structure-bioactive SeNPs via polysaccharide-polyphenol interactions.

Hydroxyapatite nanoparticles-cell interaction: New approaches to disclose the fate of membrane-bound and internalised nanoparticles

Hydroxyapatite nanoparticles are popular tools in bone regeneration, but they have also been used for gene delivery and as anticancer drugs. Understanding their mechanism of action, particularly for the latter application, is crucial to predict their toxicity. To this end, we aimed to elucidate the importance of nanoparticle membrane interactions in the cytotoxicity of MG-63 cells using two different types of nanoparticles. In addition, conventional techniques for studying nanoparticle internalisation were evaluated and compared with newer and less exploited approaches. Hydroxyapatite and magnesium-doped hydroxyapatite nanoparticles were used as suspensions or compacted as specular discs. Comparison between cells seeded on the discs and those supplemented with the nanoparticles allowed direct interaction of the cell membrane with the material to be ruled out as the main mechanism of toxicity. In addition, standard techniques such as flow cytometry were inconclusive when used to assess nanoparticles toxicity. Interestingly, the use of intracellular calcium fluorescent probes revealed the presence of a high number of calcium-rich vesicles after nanoparticle supplementation in cell culture. These structures could not be detected by transmission electron microscopy due to their liquid content. However, by using cryo-soft X-ray imaging, which was used to visualise the cellular ultrastructure without further treatment other than vitrification and to quantify the linear absorption coefficient of each organelle, it was possible to identify them as multivesicular bodies, potentially acting as calcium stores. In the study, an advanced state of degradation of the hydroxyapatite and magnesium-doped hydroxyapatite nanoparticles within MG-63 cells was observed. Overall, we demonstrate that the combination of fluorescent calcium probes together with cryo-SXT is an excellent approach to investigate intracellular calcium, especially when found in its soluble form.

Nanoparticulate cell-free DNA scavenger for treating inflammatory bone loss in periodontitis

Periodontitis is a common type of inflammatory bone loss and a risk factor for systemic diseases. The pathogenesis of periodontitis involves inflammatory dysregulation, which represents a target for new therapeutic strategies to treat periodontitis. After establishing the correlation of cell-free DNA (cfDNA) level with periodontitis in patient samples, we test the hypothesis that the cfDNA-scavenging approach will benefit periodontitis treatment. We create a nanoparticulate cfDNA scavenger specific for periodontitis by coating selenium-doped hydroxyapatite nanoparticles (SeHANs) with cationic polyamidoamine dendrimers (PAMAM-G3), namely G3@SeHANs, and compare the activities of G3@SeHANs with those of soluble PAMAM-G3 polymer. Both G3@SeHANs and PAMAM-G3 inhibit periodontitis-related proinflammation in vitro by scavenging cfDNA and alleviate inflammatory bone loss in a mouse model of ligature-induced periodontitis. G3@SeHANs also regulate the mononuclear phagocyte system in a periodontitis environment, promoting the M2 over the M1 macrophage phenotype. G3@SeHANs show greater therapeutic effects than PAMAM-G3 in reducing proinflammation and alveolar bone loss in vivo. Our findings demonstrate the importance of cfDNA in periodontitis and the potential for using hydroxyapatite-based nanoparticulate cfDNA scavengers to ameliorate periodontitis.

Biogenic Selenium Nanoparticles and Their Anticancer Effects Pertaining to Probiotic Bacteria—A Review

Selenium nanoparticles (SeNPs) can be produced by biogenic, physical, and chemical processes. The physical and chemical processes have hazardous effects. However, biogenic synthesis (by microorganisms) is an eco-friendly and economical technique that is non-toxic to human and animal health. The mechanism for biogenic SeNPs from microorganisms is still not well understood. Over the past two decades, extensive research has been conducted on the nutritional and therapeutic applications of biogenic SeNPs. The research revealed that biogenic SeNPs are considered novel competitors in the pharmaceutical and food industries, as they have been shown to be virtually non-toxic when used in medical practice and as dietary supplements and release only trace amounts of Se ions when ingested. Various pathogenic and probiotic/nonpathogenic bacteria are used for the biogenic synthesis of SeNPs. However, in the case of biosynthesis by pathogenic bacteria, extraction and purification techniques are required for further useful applications of these biogenic SeNPs. This review focuses on the applications of SeNPs (derived from probiotic/nonpathogenic organisms) as promising anticancer agents. This review describes that SeNPs derived from probiotic/nonpathogenic organisms are considered safe for human consumption. These biogenic SeNPs reduce oxidative stress in the human body and have also been shown to be effective against breast, prostate, lung, liver, and colon cancers. This review provides helpful information on the safe use of biogenic SeNPs and their economic importance for dietary and therapeutic purposes, especially as anticancer agents.

Hydroxyapatite Biobased Materials for Treatment and Diagnosis of Cancer

Great advances in cancer treatment have been undertaken in the last years as a consequence of the development of new antitumoral drugs able to target cancer cells with decreasing side effects and a better understanding of the behavior of neoplastic cells during invasion and metastasis. Specifically, drug delivery systems (DDS) based on the use of hydroxyapatite nanoparticles (HAp NPs) are gaining attention and merit a comprehensive review focused on their potential applications. These are derived from the intrinsic properties of HAp (e.g., biocompatibility and biodegradability), together with the easy functionalization and easy control of porosity, crystallinity and morphology of HAp NPs. The capacity to tailor the properties of DLS based on HAp NPs has well-recognized advantages for the control of both drug loading and release. Furthermore, the functionalization of NPs allows a targeted uptake in tumoral cells while their rapid elimination by the reticuloendothelial system (RES) can be avoided. Advances in HAp NPs involve not only their use as drug nanocarriers but also their employment as nanosystems for magnetic hyperthermia therapy, gene delivery systems, adjuvants for cancer immunotherapy and nanoparticles for cell imaging.

Integrated microfluidic-SERS for exosome biomarker profiling and osteosarcoma diagnosis

Osteosarcoma is one of the most frequent primary sarcoma of bone among adolescents. Early diagnosis of osteosarcoma is the key factor to achieve high survival rate of patients. Nevertheless, traditional histological biopsy is highly invasive and associated with the risk of arousing tumor spread. Herein, we develop a method integrating microfluidics and surface-enhanced Raman spectroscopy (SERS) to isolate plasma-derived exosomes and profile multiple exosomal biomarkers for the diagnosis of osteosarcoma. The method showed highly efficient isolation of exosomes directly from human plasma and can profile exosomes based on protein biomarkers, with the detection limit down to 2 exosomes per μL. The whole assay can be performed in 5 h and only consumed 50 μL of plasma for one analysis. With the method, we analyzed the level of three protein biomarkers, i.e., CD63, vimentin (VIM) and epithelial cell adhesion molecule (EpCAM), on plasma-derived exosomes from 20 osteosarcoma patients and 20 heathy controls. Significantly higher levels of CD63, VIM and EpCAM were observed on plasma exosomes from the osteosarcoma patients compared to the healthy controls. Based on the level of the exosomal biomarkers, a classification model was built for the rapid diagnosis of osteosarcoma, with the sensitivity, specificity and accuracy of 100%, 90% and 95%, respectively. The proposed method does not require complex operations nor expensive equipment, and has great promise in clinical diagnosis of cancer as a liquid biopsy technique.

A Selective Reduction of Osteosarcoma by Mitochondrial Apoptosis Using Hydroxyapatite Nanoparticles

Background

In recent years, using hydroxyapatite nanoparticles (HANPs) for tumor therapy attracted increasing attention because HANPs were found to selectively suppress the growth of tumor cells but exhibit ignorable toxicity to normal cells.

Purpose

This study aimed to investigate the capacities of HANPs with different morphologies and particle sizes against two kinds of osteosarcoma (OS) cells, human OS 143B cells and rat OS UMR106 cells.

Methods

Six kinds of HANPs with different morphologies and particle sizes were prepared by wet chemical method. Then, the antitumor effect of these nanoparticles was characterized by means of in vitro cell experiments and in vivo tumor-bearing mice model. The underlying antitumor mechanism involving mitochondrial apoptosis was also investigated by analysis of intracellular calcium, expression of apoptosis-related genes, reactive oxygen species (ROS), and the endocytosis efficiency of the particles in tumor cells.

Results

Both in vitro cell experiments and in vivo mice model evaluation revealed the anti-OS performance of HANPs depended on the concentration, morphology, and particle size of the nanoparticles, as well as the OS cell lines. Among the six HANPs, rod-like HANPs (R-HANPs) showed the best inhibitory activity on 143B cells, while needle-like HANPs (N-HANPs) inhibited the growth of UMR106 cells most efficiently. We further demonstrated that HANPs induced mitochondrial apoptosis by selectively raising intracellular Ca²⁺ and the gene expression levels of mitochondrial apoptosis-related molecules, and depolarizing mitochondrial membrane potential in tumor cells but not in MC3T3-E1, a mouse pre-osteoblast line. Additionally, the anti-OS activity of HANPs also linked with the endocytosis efficiency of the particles in the tumor cells, and their ability to drive oxidative damage and immunogenic cell death (ICD).

Conclusion

The current study provides an effective strategy for OS therapy where the effectiveness was associated with the particle morphology and cell line.

Reactive sulfur and selenium species in the regulation of bone homeostasis

Reactive oxygen species (ROS) are important modulators of physiological signaling and play important roles in bone tissue regulation. Both reactive sulfur species (RSS) and reactive selenium species (RSeS) are involved in ROS signaling, and recent work suggests RSS and RSeS involvement in the regulation of bone homeostasis. For example, RSS can promote osteogenic differentiation and decrease osteoclast activity and differentiation, and the antioxidant activity of RSeS play crucial roles in balancing bone remodeling. Here, we outline current research progress on the application of RSS and RSeS in bone disease and regeneration. Focusing on these investigations, we highlight different methods, tools, and sources of RSS and RSeS, and we also highlight future opportunities for delivery of RSS and RSeS in biological environments relating to bone.

Research progress of bone-targeted drug delivery system on metastatic bone tumors

Bone metastases are common in malignant tumors and the effect of conventional treatment is limited. How to effectively inhibit tumor bone metastasis and deliver the drug to the bone has become an urgent issue to be solved. While bone targeting drug delivery systems have obvious advantages in the treatment of bone tumors. The research on bone-targeted anti-tumor therapy has made significant progress in recent years. We introduced the related tumor pathways of bone metastases. The tumor microenvironment plays an important role in metastatic bone tumors. We introduce a drug-loading systems based on different environment-responsive nanocomposites for anti-tumor and anti-metastatic research. According to the process of bone metastases and the structure of bone tissue, we summarized the information on bone-targeting molecules. Bisphosphate has become the first choice of bone-targeted drug delivery carrier because of its affinity with hydroxyapatite in bone. Therefore, we sought to summarize the bone-targeting molecule of bisphosphate to identify the modification effect on bone-targeting. And this paper discusses the relationship between bisphosphate bone targeting molecular structure and drug delivery carriers, to provide some new ideas for the research and development of bone-targeting drug delivery carriers. Targeted therapy will make a more outstanding contribution to the treatment of tumors.

Chiral FA Conjugated CdTe/CdS Quantum Dots for Selective Cancer Ablation

Inducing apoptosis in cancer cells is considered a potential therapeutic mechanism underlying cancers. Here, chiral folic acid (FA) conjugated Cys-CdTe/CdS quantum dots (QDs) conjugated with a cancer-targeting ligand were fabricated to induce apoptosis in vivo. Ligand-induced chirality mechanism for FA-Cys-CdTe/CdS QDs was discussed, which is verified by density functional theory (DFT) simulation. Interestingly, we found that the circular dichroism (CD) signals of chiral QDs can effectively distinguish breast cancer cells from normal cells, where a sharp decrease in CD signal and absorption intensity can be seen. Notably, chiral FA-Cys-CdTe/CdS QDs showed significant apoptosis-inducing ability after the release of mitochondrial apoptotic factors. Furthermore, in vivo experiments showed that chiral FA-Cys-CdTe/CdS QDs provide an efficient cancer ablation through the apoptosis process with negligible toxicity, demonstrating their great potential utility in targeted anticancer agent for future clinic application.

Albumin-assembled copper-bismuth bimetallic sulfide bioactive nanosphere as an amplifier of oxidative stress for enhanced radio-chemodynamic combination therapy

The tumor microenvironment with overexpressed hydrogen peroxide (H2O2) and reinforced antioxidative system (glutathione, GSH) becomes a double-edged sword for the accessibility of nano-therapy. Since reactive oxygen species (ROS) are easily quenched by the developed antioxidative network, ROS-based treatments such as chemodynamic therapy (CDT) and radiotherapy (RT) for killing cancer cells are severely attenuated. To overcome such limitations, a bioactive nanosphere system is developed to regulate intracellular oxidative stress for enhanced radio-chemodynamic combination therapy by using bovine serum albumin (BSA) based bioactive nanospheres that are BSA assembled with in situ generated copper-bismuth sulfide nanodots and diallyl trisulfide (DATS). The copper-bismuth sulfide nanodots react with H2O2 to produce •OH and release Cu2+. Then, the Cu2+ further depletes GSH to generate Cu+ for more •OH generation in the way of Fenton-like reaction. Such a cascade reaction can initiate •OH generation and GSH consumption to realize CDT. The elevation of ROS triggered by the DATS from BBCD nanospheres further augments the breaking of redox balance for the increased oxidative stress in 4T1 cells. With the sensitization of increased oxidative stress and high Z element Bi, an enhanced radio-chemodynamic combination therapy is achieved. The current work provides an enhanced radio-chemodynamic combination treatment for the majority of solid tumors by using the co-assembled bioactive nanospheres as an amplifier of oxidative stress.

Bifunctional scaffolds for tumor therapy and bone regeneration: Synergistic effect and interplay between therapeutic agents and scaffold materials

Bone tumor patients often face the problems with cancer cell residues and bone defects after the operation. Therefore, researchers have developed many bifunctional scaffolds with both tumor treatment and bone repair functions. Therapeutic agents are usually combined with bioactive scaffolds to achieve the "bifunctional". However, the synergistic effect of bifunctional scaffolds on tumor therapy and bone repair, as well as the interplay between therapeutic agents and scaffold materials in bifunctional scaffolds, have not been emphasized and discussed. This review proposes a promising design scheme for bifunctional scaffolds: the synergistic effect and interplay between the therapeutic agents and scaffold materials. This review summarizes the latest research progress in bifunctional scaffolds for therapeutic applications and regeneration. In particular, it summarizes the role of tumor therapeutic agents in bone regeneration and the role of scaffold materials in tumor treatment. Finally, a perspective on the future development of bifunctional scaffolds for tumor therapy and bone regeneration is discussed.

Electrodeposition of Calcium Phosphate Coatings on Metallic Substrates for Bone Implant Applications: A Review

This review summaries more than three decades of scientific knowledge on electrodeposition of calcium phosphate coatings. This low-temperature process aims to make the surface of metallic bone implants bioactive within a physiological environment. The first part of the review describes the reaction mechanisms that lead to the synthesis of a bioactive coating. Electrodeposition occurs in three consecutive steps that involve electrochemical reactions, pH modification, and precipitation of the calcium phosphate coating. However, the process also produces undesired dihydrogen bubbles during the deposition because of the reduction of water, the solvent of the electrolyte solution. To prevent the production of large amounts of dihydrogen bubbles, the current density value is limited during deposition. To circumvent this issue, the use of pulsed current has been proposed in recent years to replace the traditional direct current. Thanks to breaking times, dihydrogen bubbles can regularly escape from the surface of the implant, and the deposition of the calcium phosphate coating is less disturbed by the accumulation of bubbles. In addition, the pulsed current has a positive impact on the chemical composition, morphology, roughness, and mechanical properties of the electrodeposited calcium phosphate coating. Finally, the review describes one of the most interesting properties of electrodeposition, i.e., the possibility of adding ionic substituents to the calcium phosphate crystal lattice to improve the biological performance of the bone implant. Several cations and anions are reviewed from the scientific literature with a description of their biological impact on the physiological environment.

Application of additively manufactured 3D scaffolds for bone cancer treatment: a review

Bone cancer is a critical health problem on a global scale, and the associated huge clinical and economic burdens are still rising. Although many clinical approaches are currently used for bone cancer treatment, these methods usually affect the normal body functions and thus present significant limitations. Meanwhile, advanced materials and additive manufacturing have opened up promising avenues for the development of new strategies targeting both bone cancer treatment and post-treatment bone regeneration. This paper presents a comprehensive review of bone cancer and its current treatment methods, particularly focusing on a number of advanced strategies such as scaffolds based on advanced functional materials, drug-loaded scaffolds, and scaffolds for photothermal/magnetothermal therapy. Finally, the main research challenges and future perspectives are elaborated.

SERS and MALDI-TOF MS based plasma exosome profiling for rapid detection of osteosarcoma

Osteosarcoma is the most frequent primary bone cancer, particularly among children and adolescents. The early diagnosis of osteosarcoma is significant for timely clinical treatment to reduce the mortality of patients. Exosomes play a significant role in intercellular communication and serve as promising biomarkers in liquid biopsy for the diagnosis and monitoring of tumors. Herein, we report the utility of surface-enhanced Raman scattering (SERS) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) for rapid identification of osteosarcoma. We firstly profiled the intrinsic SERS signals and MALDI-TOF mass fingerprints of different subgroups of extracellular vesicles (EVs) and the corresponding cells, demonstrating that the SERS signals and MALDI-TOF mass spectra of exosomes from different types of cells were more discriminative compared to those of large and medium EVs and the cells themselves. Then, we characterized plasma-derived exosomes of 15 osteosarcoma patients and 15 healthy volunteers using SERS and MALDI-TOF MS, revealing distinctive biochemical differences in the spectra. We further utilized a data fusion approach to combine the two types of spectroscopic techniques, differentiating osteosarcoma patients from healthy controls with higher precision than either technique. The results reveal that the non-invasive liquid biopsy method using SERS and MALDI-TOF MS fingerprinting of exosomes has great potential for rapid diagnosis of osteosarcoma.