NIR-responsive molybdenum (Mo)-based nanoclusters enhance ROS scavenging for osteoarthritis therapy

Hydrogel-mediated delivery of baicalein for the effective therapy of MRSA-infected diabetic wounds by immune response and moderate photothermal effects

Persistent bacterial infections and the imbalance in immune regulation induced by oxidative stress present a significant challenge in diabetic wound healing. In this study, we developed a novel dual-network hydrogel system composed of chitosan/polyacrylic acid (PEC) and polyoxometalate PMo12 (PMo12-PEC) loaded with baicalein (BA), designated as PMo12-BA-PEC, for the treatment of methicillin-resistant Staphylococcus aureus (MRSA)-infected diabetic wounds. The hydrogel demonstrated enhanced mechanical strength and elasticity, facilitating effective wound adherence and accommodating tissue movement. Upon 808 nm near-infrared (NIR) light irradiation, the photothermal properties of PMo12 enabled controlled low-temperature hyperthermia and accelerated BA release. Remarkably, the hydrogel achieved an antibacterial efficacy of 99.45% ± 0.12% against MRSA following 5 minutes of NIR exposure while exhibiting potent antioxidant and anti-inflammatory capabilities to scavenge reactive oxygen species and mitigate inflammatory responses. Comprehensive evaluation revealed that the PMo12-BA-PEC hydrogel significantly promoted angiogenesis, enhanced collagen deposition, inhibited bacterial growth, and modulated immune regulation, thereby accelerating the wound healing process in diabetic rat models. These findings suggest that the PMo12-BA-PEC hydrogel represents a promising biomaterial platform for clinical management of diabetic wounds and potential treatment of oxidative stress-related disorders.

A supramolecular assembly strategy for the treatment of rheumatoid arthritis with ultrasound-augmented inflammatory microenvironment reprograming

As regulators and promotors of joint erosion, pro-inflammatory M1-like macrophages play pivotal roles in the pathogenesis of rheumatoid arthritis (RA). Here, we develop a supramolecular self-assembly (PCSN@MTX) of molybdenum (Mo) based polyoxometalate (POM), β-cyclodextrin (β-CD), and methotrexate (MTX), in which the MTX is loaded by host-guest interaction. PCSN@MTX shows inhibition of synovial M1-like macrophages polarization to alleviate RA. PCSN@MTX has demonstrated ultrasound (US) augmented catalytic behavior in consuming ROS and generating oxygen (O2) with accelerated conversion of Mo5+ to Mo6+ in the POM. In the collagen-induced arthritis mouse model, after systemical administration, the pH-responsive PCSN@MTX shows enhanced accumulation in the acidic joints by in-situ self-assembly. The host-guest complexation between MTX and β-CD is broken via US, achieving an on-demand burst release of MTX. The released MTX and ROS-scavenging synergistically facilitate the M1-to-M2 macrophage phenotype switching, which effectively alleviates RA disease progress under US irradiation. This study provides a paradigm for RA therapy with a promising US-augmented strategy.

Photoacoustic Imaging in Inflammatory Orthopedic Diseases: Progress toward Precise Diagnostics and Predictive Regulation

With the intensification of aging issues, inflammatory orthopedic diseases almost occur in the majority of elderly people, which is becoming increasingly severe. Photoacoustic imaging (PAI) is a non-invasive visualization technique for a clear diagnosis of the inflammation areas through detecting acoustic signals generated by the laser irradiation. The combination of "light input" and "acoustic output" provides unprecedented scalability as well as high penetration depth and resolution. This new imaging technology can also present more anatomical information and feedback status of inflammatory activity for the orthopedic diseases. Especially in inflammation imaging, this technology can effectively supplement current clinical imaging methods in diagnosis, staging, and monitoring of pathophysiological processes. With the rapid development of these new technologies, the goals of precise diagnosis, predictive regulation, and ultimately personalized treatment strategies are becoming increasingly realistic. Herein, this article introduces various orthopedic inflammations and related imaging technology applications. It covers the types of PA nanoprobes and their research progress in orthopedic inflammation, as well as the potential applications of PAI in various aspects. The review also discusses the recent researches and emerging translational applications of PAI in orthopedic inflammation, as well as the prospects and future development challenges of clinical transformation.

Microenvironment-Responsive Hydrogels Comprising Engineering Zeolitic Imidazolate Framework-8-Anchored Parathyroid Hormone-Related Peptide-1 for Osteoarthritis Therapy

Intra-articular drug injections are effective for osteoarthritis (OA), but challenges such as the complex microenvironment and rapid drug diffusion require frequent injections. Herein, we propose a biofunctional hydrogel-based strategy for prolonged drug delivery and microenvironment remodeling. We propose a strategy to functionalize zeolitic imidazolate framework-8 with tannic acid (TA-ZIF), anchor PTH-related peptide-1 (PTHrP-1) within this framework (TA-ZIF@P1) and incorporate a phenylboronic acid-modified gelatin-based hydrogel (GP hydrogel) drug delivery system (GP@TA-ZIF@P1, GPTP hydrogel) with responsive release properties that respond to the pathological microenvironments of OA. The GPTP hydrogel facilitated controlled, sustained release of PTHrP-1 via dynamic boronic esters, with in vitro and in vivo studies showing continuous release for over 28 days. It not only promotes chondrocyte proliferation but also exhibits significant cytoprotective effects under hyperactive ROS and IL-1β-induced conditions. Notably, transcriptome sequencing confirms that the GPTP hydrogel facilitates both chondrocyte proliferation and chondrogenesis under inflammatory conditions by deactivating Wnt/β-Catenin signaling pathways and enhancing the PI3K/AKT signaling pathway. Additionally, the GPTP hydrogel delays the catabolic metabolism of cartilage explants from mice in inflammatory environments. In a surgical model of mouse OA, we show that the intra-articular injection of GPTP hydrogels reduced periarticular bone remodeling and promoted the production of glycosaminoglycans while offering chondroprotection against cartilage degeneration. To sum up, this pioneering research on PTHrP-1 as a treatment for OA, combined with the GPTP hydrogel system, offers valuable insights and a paradigm for the controlled and sustained release of PTHrP-1, representing a significant advancement in OA treatment strategies.

Polyoxometalate-based injectable coacervate inhibits HCC metastasis after incomplete radiofrequency ablation via scavenging ROS

BACKGROUND

Incomplete radiofrequency ablation (iRFA) stimulates residual hepatocellular carcinoma (HCC) metastasis, leading to a poor prognosis for patients. Therefore, it is imperative to develop an effective therapeutic strategy to prevent iRFA-induced HCC metastasis.

RESULTS

Our study revealed that iRFA induced an abnormal increase in ROS levels within residual HCC, which enhanced tumor cell invasiveness and promoted macrophage M2 polarization, ultimately facilitating HCC metastasis. Molybdenum-based polyoxometalate (POM) is an excellent ROS-scavenging nanocluster, but its size is too small to be easily cleared by the kidneys, limiting its effectiveness in scavenging iRFA-induced ROS. To overcome this limitation, we synthesized an injectable POM-loaded coacervate delivery system named POM@Coa, which can sustainably scavenge iRFA-induced ROS by slowly releasing POM. POM@Coa markedly reduced HCC invasiveness, reversed macrophage polarization from M2 to M1, and promoted the infiltration and activation of CD8+ T cells, ultimately inhibiting HCC metastasis. Importantly, POM@Coa showed superior therapeutic efficacy to free POM in the absence of systemic toxicity.

CONCLUSIONS

POM@Coa exhibits the potential to decrease HCC invasiveness and activate anti-tumor immunity, opening up new avenues for the safe and effective treatment and prevention of HCC metastasis when combined with RFA.

Metal ion-crosslinking multifunctional hydrogel microspheres with inflammatory immune regulation for cartilage regeneration

Introduction

Osteoarthritis (OA) is a degenerative disease of the joints characterized by cartilage degradation and synovial inflammation. Due to the complex pathogenesis of OA, multifaceted therapies that modulate inflammatory and immune microenvironmental disturbances while promoting cartilage regeneration are key to control the progression of OA.

Methods

Herein, a multifunctional nanoparticle (DIC/Mg-PDA NPs) was constructed successfully by the metal chelation effect between Mg2+ and catecholamine bond from dopamine, followed by the amidation with diclofenac (DIC), which was then prepared into an injectable hydrogel microsphere (DIC/Mg-PDA@HM) with immune-regulating and cartilage-repairing abilities through microfluidic technology for the treatment of osteoarthritis.

Results and discussion

The sustained release of Mg2+ from the composite hydrogel microspheres achieved inflammatory immune regulation by converting macrophages from M1 to M2 and promoted cartilage regeneration through the differentiation of BMSCs. Moreover, the enhanced release of DIC and polydopamine (PDA) effectively downregulated inflammatory factors, and finally achieved OA therapy. In addition, in vivo MRI and tissue section staining of OA model proved the significant efficacy of the hydrogel microspheres on OA. In conclusion, these novel hydrogel microspheres demonstrated a promising prospect for multidisciplinary repairing of OA.

Engineering Stimuli-Responsive Materials for Precision Medicine

Over the past decade, precision medicine has garnered increasing attention, making significant strides in discovering new therapeutic drugs and mechanisms, resulting in notable achievements in symptom alleviation, pain reduction, and extended survival rates. However, the limited target specificity of primary drugs and inter-individual differences have often necessitated high-dosage strategies, leading to challenges such as restricted deep tissue penetration rates and systemic side effects. Material science advancements present a promising avenue for these issues. By leveraging the distinct internal features of diseased regions and the application of specific external stimuli, responsive materials can be tailored to achieve targeted delivery, controllable release, and specific biochemical reactions. This review aims to highlight the latest advancements in stimuli-responsive materials and their potential in precision medicine. Initially, we introduce disease-related internal stimuli and capable external stimuli, elucidating the reaction principles of responsive functional groups. Subsequently, we provide a detailed analysis of representative pre-clinical achievements of stimuli responsive materials across various clinical applications, including enhancements in the treatment of cancers, injury diseases, inflammatory diseases, infection diseases, and high-throughput microfluidic biosensors. Finally, we discuss some clinical challenges, such as off-target effects, long-term impacts of nano-materials, potential ethical concerns, and offer insights into future perspectives of stimuli-responsive materials.

Controlled Stimulus-Responsive Delivery Systems for Osteoarthritis Treatment

Osteoarthritis (OA), a common and disabling degenerative joint disease, affects millions of people worldwide and imposes a considerable burden on patients and society due to its high prevalence and economic costs. The pathogenesis of OA is closely related to the progressive degradation of articular cartilage and the accompany inflammation; however, articular cartilage itself cannot heal and modulate the inflammation due to the lack of nerves, blood vessels, and lymph-vessels. Therefore, reliable and effective methods to treat OA remain highly desired. Local administration of drugs or bioactive materials by intra-articular injection of the delivery system represents a promising approach to treat OA, especially considering the prolonged joint retention, cartilage or chondrocytes targeting, and stimuli-responsive release to achieve precision OA therapy. This article summarizes and discusses the advances in the currently used delivery systems (nanoparticle, hydrogel, liposome, and microsphere) and then focuses on their applications in OA treatment from the perspective of endogenous stimulus (redox reactions, pH, enzymes, and temperature) and exogenous stimulus (near-infrared, magnetic, and ultrasound)-responsive release. Finally, the challenges and potential future directions for the development of nano-delivery systems are summarized.

NIR-responsive nano-holed titanium alloy surfaces: a photothermally activated antimicrobial biointerface

Among external stimuli-responsive therapy approaches, those using near infrared (NIR) light irradiation have attracted significant attention to treat bone-related diseases and bone tissue regeneration. Therefore, the development of metallic biomaterials sensitive to NIR stimuli is an important area of research in orthopaedics. In this study, we have generated in situ prism-shaped silver nanoparticles (p-AgNPs) in a biomorphic nano-holed TiO2 coating on a Ti6Al4V alloy (a-Ti6Al4V). Insertion of p-AgNPs does not disturb the periodically arranged sub-wavelength-sized unit cell on the a-Ti6Al4V dielectric structure, while they exacerbate its peculiar optical response, which results in a higher NIR reflectivity and high efficiency of NIR photothermal energy conversion suitable to bacterial annihilation. Together, these results open a promising path toward strategic bone therapeutic procedures, providing novel insights into precision medicine.

Injectable and NIR-responsive CDN-POM hydrogels for combined non-inflammatory photo-immunotherapy

Similar to clinically applied thermal ablation techniques, the cellular necrosis that occurs during photothermal tumor therapy (PTT) can induce inflammatory response, severely compromising the therapeutic efficacy and clinical translation of the PTT. Inspired by the remarkable ROS-scavenging activity and high photothermal efficiency of molybdenum-based polyoxometalate (POM) and the immunostimulatory effect of cyclic dinucleotides (CDNs), a NIR-responsive and injectable DNA-mediated hybrid hydrogel (CDN-POM) has been developed. The hydrogels have superior photothermal efficiency (43.41%) to POM, impressive anti-inflammatory capability and prolonged intratumoral CDN-releasing behavior, thus enabling synergistic anti-tumor therapeutic outcomes. Meanwhile, local treatment induced by CDN-POM hydrogels displays minimal side effects on normal tissue. Taking advantage of the high phototherapeutic effect, ROS-scavenging activity and sustained CDN release of CDN-POM hydrogels, a novel combined approach that integrates photothermal therapy and immunotherapy of breast tumor is successfully pioneered.

Polyoxometalate inhibition of SOX2-mediated tamoxifen resistance in breast cancer

BACKGROUND

Increased cancer stem cell (CSC) content and SOX2 overexpression are common features in the development of resistance to therapy in hormone-dependent breast cancer, which remains an important clinical challenge. SOX2 has potential as biomarker of resistance to treatment and as therapeutic target, but targeting transcription factors is also challenging. Here, we examine the potential inhibitory effect of different polyoxometalate (POM) derivatives on SOX2 transcription factor in tamoxifen-resistant breast cancer cells.

METHODS

Various POM derivatives were synthesised and characterised by infrared spectra, powder X-ray diffraction pattern and nuclear magnetic resonance spectroscopy. Estrogen receptor (ER) positive breast cancer cells, and their counterparts, which have developed resistance to the hormone therapy tamoxifen, were treated with POMs and their consequences assessed by gel retardation and chromatin immunoprecipitation to determine SOX2 binding to DNA. Effects on proliferation, migration, invasion and tumorigenicity were monitored and quantified using microscopy, clone formation, transwell, wound healing assays, flow cytometry and in vivo chick chorioallantoic membrane (CAM) models. Generation of lentiviral stable gene silencing and gene knock-out using CRISPR-Cas9 genome editing were applied to validate the inhibitory effects of the selected POM. Cancer stem cell subpopulations were quantified by mammosphere formation assays, ALDEFLUOR activity and CD44/CD24 stainings. Flow cytometry and western blotting were used to measure reactive oxygen species (ROS) and apoptosis.

RESULTS

POMs blocked in vitro binding activity of endogenous SOX2. [P2W18O62]6- (PW) Wells-Dawson-type anion was the most effective at inhibiting proliferation in various cell line models of tamoxifen resistance. 10 µM PW also reduced cancer cell migration and invasion, as well as SNAI2 expression levels. Treatment of tamoxifen-resistant cells with PW impaired tumour formation by reducing CSC content, in a SOX2-dependent manner, which led to stem cell depletion in vivo. Mechanistically, PW induced formation of reactive oxygen species (ROS) and inhibited Bcl-2, leading to the death of tamoxifen-resistant cells. PW-treated tamoxifen-resistant cells showed restored sensitivity to tamoxifen.

CONCLUSIONS

Together, these observations highlight the potential use of PW as a SOX2 inhibitor and the therapeutic relevance of targeting SOX2 to treat tamoxifen-resistant breast cancer.

Impact of nanosilver surface electronic distributions on serum protein interactions and hemocompatibility

The translation of silver-based nanotechnology 'from bench to bedside' requires a deep understanding of the molecular aspects of its biological action, which remains controversial at low concentrations and non-spherical morphologies. Here, we present a hemocompatibility approach based on the effect of the distinctive electronic charge distribution in silver nanoparticles (nanosilver) on blood components. According to spectroscopic, volumetric, microscopic, dynamic light scattering measurements, pro-coagulant activity tests, and cellular inspection, we determine that at extremely low nanosilver concentrations (0.125-2.5μg ml-1), there is a relevant interaction effect on the serum albumin and red blood cells (RBCs). This explanation has its origin in the surface charge distribution of nanosilver particles and their electron-mediated energy transfer mechanism. Prism-shaped nanoparticles, with anisotropic charge distributions, act at the surface level, generating a compaction of the native protein molecule. In contrast, the spherical nanosilver particle, by exhibiting isotropic surface charge, generates a polar environment comparable to the solvent. Both morphologies induce aggregation at NPs/bovine serum albumin ≈ 0.044 molar ratio values without altering the coagulation cascade tests; however, the spherical-shaped nanosilver exerts a negative impact on RBCs. Overall, our results suggest that the electron distributions of nanosilver particles, even at extremely low concentrations, are a critical factor influencing the molecular structure of blood proteins' and RBCs' membranes. Isotropic forms of nanosilver should be considered with caution, as they are not always the least harmful.

The common link between sleep apnea syndrome and osteoarthritis: a literature review

Patients with Osteoarthritis (OA) often also suffer from Sleep Apnea Syndrome (SAS), and many scholars have started to notice this link, although the relationship between the two is still unclear. In this review, we aim to summarize the current literature on these two diseases, integrate evidence of the OA and OSA connection, explore and discuss their potential common mechanisms, and thus identify effective treatment methods for patients with both OA and SAS. Some shared characteristics of the two conditions have been identified, notably aging and obesity as mutual risk factors. Both diseases are associated with various biological processes or molecular pathways, including mitochondrial dysfunction, reactive oxygen species production, the NF-kB pathway, HIF, IL-6, and IL-8. SAS serves as a risk factor for OA, and conversely, OA may influence the progression of SAS. The effects of OA on SAS are underreported in the literature and require more investigation. To effectively manage these patients, timely intervention for SAS is necessary while treating OA, with weight reduction being a primary requirement, alongside combined treatments such as Continuous positive airway pressure (CPAP) and medications. Additionally, numerous studies in drug development are now aimed at inhibiting or clearing certain molecular pathways, including ROS, NF-KB, IL-6, and IL-8. Improving mitochondrial function might represent a viable new strategy, with further research into mitochondrial updates or transplants being essential.

Multifunctional Molybdenum-Based Nanoclusters Engineered Gelatin Methacryloyl as In Situ Photo-Cross-Linkable Hybrid Hydrogel Dressings for Enhanced Wound Healing

Skin injuries and wounds present significant clinical challenges, necessitating the development of advanced wound dressings for efficient wound healing and tissue regeneration. In this context, the advancement of hydrogels capable of counteracting the adverse effects arising from undesirable reactive oxygen species (ROS) is of significant importance. This study introduces a hybrid hydrogel with rapid photocuring and excellent conformability, tailored to ameliorate the hostile microenvironment of damaged skin tissues. The hybrid hydrogel, composed of photoresponsive Gelatin Methacryloyl (GelMA) and Molybdenum-based nanoclusters (MNC), exhibits physicochemical characteristics conductive to skin regeneration. In vitro studies demonstrated the cytocompatibility and ROS-responsive behavior of the MNC/GelMA hybrid hydrogels, confirming their ability to promote human dermal fibroblasts (HDF) functions. The incorporation of MNC into GelMA not only enhances HDF adhesion, proliferation, and migration but also shields against oxidative damage induced by hydrogen peroxide (H2O2). Notably, in vivo evaluation in murine full-thickness skin defects revealed that the application of hybrid hydrogel dressings led to reduced inflammation, accelerated wound closure, and enhanced collagen deposition in comparison to control groups. Significantly, this study introduced a convenient approach to develop in situ ROS-scavenging hydrogel dressings to accelerate the wound healing process without the need for exogenous cytokines or medications. We consider that the nanoengineering approach proposed herein offers potential possibilities for the development of therapeutic hydrogel dressings addressing various skin-related conditions.

Functional Nanomaterials for the Treatment of Osteoarthritis

Osteoarthritis (OA) is the most common degenerative joint disease, affecting more than 595 million people worldwide. Nanomaterials possess superior physicochemical properties and can influence pathological processes due to their unique structural features, such as size, surface interface, and photoelectromagnetic thermal effects. Unlike traditional OA treatments, which suffer from short half-life, low stability, poor bioavailability, and high systemic toxicity, nanotherapeutic strategies for OA offer longer half-life, enhanced targeting, improved bioavailability, and reduced systemic toxicity. These advantages effectively address the limitations of traditional therapies. This review aims to inspire researchers to develop more multifunctional nanomaterials and promote their practical application in OA treatment.

Recent Advances in Nanomedicine for Ocular Fundus Neovascularization Disease Management

As an indispensable part of the human sensory system, visual acuity may be impaired and even develop into irreversible blindness due to various ocular pathologies. Among ocular diseases, fundus neovascularization diseases (FNDs) are prominent etiologies of visual impairment worldwide. Intravitreal injection of anti-vascular endothelial growth factor drugs remains the primary therapy but is hurdled by common complications and incomplete potency. To renovate the current therapeutic modalities, nanomedicine emerged as the times required, which is endowed with advanced capabilities, able to fulfill the effective ocular fundus drug delivery and achieve precise drug release control, thus further improving the therapeutic effect. This review provides a comprehensive summary of advances in nanomedicine for FND management from state-of-the-art studies. First, the current therapeutic modalities for FNDs are thoroughly introduced, focusing on the key challenges of ocular fundus drug delivery. Second, nanocarriers are comprehensively reviewed for ocular posterior drug delivery based on the nanostructures: polymer-based nanocarriers, lipid-based nanocarriers, and inorganic nanoparticles. Thirdly, the characteristics of the fundus microenvironment, their pathological changes during FNDs, and corresponding strategies for constructing smart nanocarriers are elaborated. Furthermore, the challenges and prospects of nanomedicine for FND management are thoroughly discussed.

Research progress on nanotechnology of traditional Chinese medicine to enhance the therapeutic effect of osteoarthritis

Osteoarthritis (OA) is a prevalent chronic condition that primarily impacts the articular cartilage and surrounding bone tissue, resulting in joint inflammation and structural deterioration. The etiology of OA is multifaceted and intricately linked to the oxidative stress response of joint tissue. Oxidative stress (OS) in OA leads to the creation of reactive oxygen species (ROS) and other oxidizing agents, resulting in detrimental effects on chondrocytes. This oxidative damage diminishes the flexibility and robustness of cartilage, thereby expediting the progression of joint deterioration. Therefore, the antioxidant effect is crucial in the treatment of OA. Currently, a considerable number of components found in traditional Chinese medicine (TCM) have been scientifically demonstrated to exhibit remarkable antioxidant and anti-inflammatory properties. Nevertheless, the utilization of this program is considerably constrained as a result of intrinsic deficiencies, notably stability concerns. The successful amalgamation of TCM components with nanotechnology has properly tackled these concerns and enhanced the efficacy of therapeutic results. The objective of this study is to delineate the antioxidant characteristics of nano-TCM and assess the current inventory of literature pertaining to the application of nano-TCM in the treatment of OA. In conclusion, this paper will now turn to the constraints and potential avenues for the advancement of nano-TCM within the realm of OA therapy.

Efficacy and safety of Gutong Patch compared with NSAIDs for knee osteoarthritis: A real-world multicenter, prospective cohort study in China

The Gutong Patch (GTP) is common in clinical practice for bone diseases. This study compared the efficacy and safety of GTP and nonsteroidal anti-inflammatory drugs (NSAIDs) for KOA patients from 35 medical centers assigned to GTP, selective COX-2 inhibitor (SCI), GTP + SCI, non-selective COX-2 inhibitor (NSCI), and GTP + NSCI groups. The visual analog scale (VAS) pain score, EuroQol-VAS, EuroQol 5D-3 L, time to articular pain relief / disappearance, and joint motion recovery were the efficacy assessments. Safety assessments included contact dermatitis, gastrointestinal disorders, etc. The p-value < 0.05 was considered statistically significant. After statistical analysis, the SCI and GTP + SCI groups showed better improvement of VAS than the GTP group; the time to articular pain relief in the NSCI group was shorter than that in GTP and SCI group; the time to joint motion recovery in the GTP + NSCI group was longer than that in the SCI group. Additionally, the improvement of the quality of life in all groups was significant after treatments. While the incidence of gastrointestinal adverse events in the NSAIDs group was higher than that in the GTP and GTP + NSAIDs groups. GTP and NSAIDs are effective for KOA patients, and GTP is more suitable for KOA patients with cardiovascular and gastrointestinal comorbidities. This study was approved by the Ethics Committee at Peking Union Medical College Hospital (HS-1766) and registered in the Chinese Clinical Trial Registry (ChiCTR2100046391).

Combined Molybdenum Gelatine Methacrylate Injectable Nano-Hydrogel Effective Against Diabetic Bone Regeneration

Introduction

Bone defects in diabetes mellitus (DM) remain a major challenge for clinical treatment. Fluctuating glucose levels in DM patients lead to excessive production of reactive oxygen species (ROS), which disrupt bone repair homeostasis. Bone filler materials have been widely used in the clinical treatment of DM-related bone defects, but overall they lack efficacy in improving the bone microenvironment and inducing osteogenesis. We utilized a gelatine methacrylate (GelMA) hydrogel with excellent biological properties in combination with molybdenum (Mo)-based polyoxometalate nanoclusters (POM) to scavenge ROS and promote osteoblast proliferation and osteogenic differentiation through the slow-release effect of POM, providing a feasible strategy for the application of biologically useful bone fillers in bone regeneration.

Methods

We synthesized an injectable hydrogel by gelatine methacrylate (GelMA) and POM. The antioxidant capacity and biological properties of the synthesized GelMA/POM hydrogel were tested.

Results

In vitro, studies showed that hydrogels can inhibit excessive reactive oxygen species (ROS) and reduce oxidative stress in cells through the beneficial effects of pH-sensitive POM. Osteogenic differentiation assays showed that GelMA/POM had good osteogenic properties with upregulated expression of osteogenic genes (BMP2, RUNX2, Osterix, ALP). Furthermore, RNA-sequencing revealed that activation of the PI3K/Akt signalling pathway in MC3T3-E1 cells with GelMA/POM may be a potential mechanism to promote osteogenesis. In an in vivo study, radiological and histological analyses showed enhanced bone regeneration in diabetic mice, after the application of GelMA/POM.

Conclusion

In summary, GelMA/POM hydrogels can enhance bone regeneration by directly scavenging ROS and activating the PI3K/Akt signalling pathway.