Hydrogen Gas from Inflammation Treatment to Cancer Therapy

The Landscape of Smart Biomaterial-Based Hydrogen Therapy

Hydrogen (H2) therapy is an emerging, novel, and safe therapeutic modality that uses molecular hydrogen for effective treatment. However, the impact of H2 therapy is limited because hydrogen molecules predominantly depend on the systemic administration of H2 gas, which cannot accumulate at the lesion site with high concentration, thus leading to limited targeting and utilization. Biomaterials are developed to specifically deliver H2 and control its release. In this review, the development process, stimuli-responsive release strategies, and potential therapeutic mechanisms of biomaterial-based H2 therapy are summarized. H2 therapy. Specifically, the produced H2 from biomaterials not only can scavenge free radicals, such as reactive oxygen species (ROS) and lipid peroxidation (LPO), but also can inhibit the danger factors of initiating diseases, including pro-inflammatory cytokines, adenosine triphosphate (ATP), and heat shock protein (HSP). In addition, the released H2 can further act as signal molecules to regulate key pathways for disease treatment. The current opportunities and challenges of H2-based therapy are discussed, and the future research directions of biomaterial-based H2 therapy for clinical applications are emphasized.

Harnessing Metal-Organic Frameworks for NIR-II Light-Driven Multiphoton Photocatalytic Water Splitting in Hydrogen Therapy

The construction of near-infrared (NIR) light-activated hydrogen-producing materials that enable the controlled generation and high-concentration release of hydrogen molecules in deep tumor tissues and enhance the effects of hydrogen therapy holds significant scientific importance. To address the key technical challenge of low-efficiency oxidation-reduction reactions for narrow-bandgap photocatalytic materials, this work proposes an innovative approach for the controllable fabrication of multiphoton photocatalytic materials to overcome the limitations imposed by traditional near-infrared photocatalysts with "narrow-bandgap" constraints. Herein, an NIR-responsive multiphoton photocatalyst, ZrTc-Co, is developed by utilizing a post-synthetic coordination modification strategy to introduce hydrogenation active site CoII into a multiphoton responsive MOF (ZrTc). The results reveal that with the introduction of the CoII site, electron-hole recombination can be efficiently suppressed, thus promoting the efficiency of hydrogen evolution reaction. In addition, the integration of CoII can effectively enhance charge transfer and improve static hyperpolarizability, which endows ZrTc-Co with excellent multiphoton absorption. Moreover, hyaluronic acid modification endows ZrTc-Co with cancer cell-specific targeting characteristics, laying the foundation for tumor-specific elimination. Collectively, the proposed findings present a strategy for constructing NIR-II light-mediated hydrogen therapeutic agents for deep tumor elimination.

Gas Therapy: Generating, Delivery, and Biomedical Applications

Oxygen (O2), nitric oxide (NO), carbon monoxide (CO), hydrogen sulfide (H2S), and hydrogen (H2) with direct effects, and carbon dioxide (CO2) with complementary effects on the condition of various diseases are known as therapeutic gases. The targeted delivery and in situ generation of these therapeutic gases with controllable release at the site of disease has attracted attention to avoid the risk of gas poisoning and improve their performance in treating various diseases such as cancer therapy, cardiovascular therapy, bone tissue engineering, and wound healing. Stimuli-responsive gas-generating sources and delivery systems based on biomaterials that enable on-demand and controllable release are promising approaches for precise gas therapy. This work highlights current advances in the design and development of new approaches and systems to generate and deliver therapeutic gases at the site of disease with on-demand release behavior. The performance of the delivered gases in various biomedical applications is then discussed.

Magnesium implants with alternating magnetic field-enhanced hydrogen release and proton depletion for anti-infection treatment and tissue repair

Implant-related osteomyelitis is a formidable hurdle in the clinical setting and is characterized by inflammation, infection, and consequential bone destruction. Therefore, effective reactive oxygen species (ROS) scavenging, bacterial killing, and subsequent bone tissue repair are urgently needed for the treatment of difficult-to-heal osteomyelitis. Herein, we utilized the eddy-thermal effect of magnesium (Mg) implants under an alternating magnetic field (AMF) for the controlled release of H2 gas and ions (OH- and Mg2+) for the treatment of osteomyelitis. H2 released by Mg rods under AMFs effectively scavenged cytotoxic ROS, exhibiting anti-inflammatory effects and consequently disrupting the environment of bacterial infections. In addition, the OH- hindered the energy metabolism of bacteria by effectively neutralizing protons within the microenvironment. Moreover, H2 impaired the permeability of bacterial membranes and expedited the damage induced by OH-. This synergistic AMF-induced H2 and proton depletion treatment approach not only killed both gram-negative and gram-positive bacteria but also effectively treated bacterial infections (abscesses and osteomyelitis). Moreover, Mg2+ released from the Mg rods enhanced and accelerated the process of bone osteogenesis. Overall, our work cleverly exploited the eddy-thermal effect and chemical activity of Mg implants under AMFs, aiming to eliminate the inflammatory environment and combat bacterial infections by the simultaneous release of H2, OH-, and Mg2+, thereby facilitating tissue regeneration. This therapeutic strategy achieved multiple benefits in one, thus presenting a promising avenue for clinical application.

Delivering Microrobots in the Musculoskeletal System

Disorders of the musculoskeletal system are the major contributors to the global burden of disease and current treatments show limited efficacy. Patients often suffer chronic pain and might eventually have to undergo end-stage surgery. Therefore, future treatments should focus on early detection and intervention of regional lesions. Microrobots have been gradually used in organisms due to their advantages of intelligent, precise and minimally invasive targeted delivery. Through the combination of control and imaging systems, microrobots with good biosafety can be delivered to the desired area for treatment. In the musculoskeletal system, microrobots are mainly utilized to transport stem cells/drugs or to remove hazardous substances from the body. Compared to traditional biomaterial and tissue engineering strategies, active motion improves the efficiency and penetration of local targeting of cells/drugs. This review discusses the frontier applications of microrobotic systems in different tissues of the musculoskeletal system. We summarize the challenges and barriers that hinder clinical translation by evaluating the characteristics of different microrobots and finally point out the future direction of microrobots in the musculoskeletal system.

Deep Red Light Driven Hydrogen Evolution by Heterojunction Polymer Dots for Diabetic Wound Healing

We describe small heterojunction polymer dots (Pdots) with deep-red light catalyzed H2 generation for diabetic skin wound healing. The Pdots with donor/acceptor heterojunctions showed remarkably enhanced photocatalytic activity as compared to the donor or acceptor nanoparticles alone. We encapsulate the Pdots and ascorbic acid into liposomes to form Lipo-Pdots nanoreactors, which selectively scavenge ⋅OH radicals in live cells and tissues under 650 nm light illumination. The antioxidant capacity of the heterojunction Pdots is ~10 times higher than that of the single-component Pdots described previously. Under a total light dose of 360 J/cm2, the Lipo-Pdots nanoreactors effectively scavenged ⋅OH radicals and suppressed the expression of pro-inflammatory cytokines in skin tissues, thereby accelerating the healing of skin wounds in diabetic mice. This study provides a feasible solution for safe and effective treatment of diabetic foot ulcers.

Endogenous Melanin and Hydrogen-Based Specific Activated Theranostics Nanoagents: A Novel Multi-Treatment Paradigm for Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a systemic autoimmune disorder characterized by excessive proliferation of rheumatoid arthritis synovial fibroblasts (RASFs) and accumulation of inflammatory cytokines. Exploring the suppression of RASFs and modulation of the RA microenvironment is considered a comprehensive strategy for RA. In this work, specifically activated nanoagents (MAHI NGs) based on the hypoxic and weakly acidic RA microenvironment are developed to achieve a second near-infrared fluorescence (NIR-II FL)/photoacoustic (PA) dual-model imaging-guided multi-treatment. Due to optimal size, the MAHI NGs passively accumulate in the diseased joint region and undergo rapid responsive degradation, precisely releasing functionalized components: endogenous melanin-nanoparticles (MNPs), hydrogen gas (H2), and indocyanine green (ICG). The released MNPs play a crucial role in ablating RASFs within the RA microenvironment through photothermal therapy (PTT) guided by accurate PA imaging. However, the regional hyperthermia generated by PTT may exacerbate reactive oxygen species (ROS) production and inflammatory response following cell lysis. Remarkably, under the acidic microenvironment, the controlled release of H2 exhibits precise synergistic antioxidant and anti-inflammatory effects with MNPs. Moreover, the ICG, the second near-infrared dye currently approved for clinical use, possesses excellent NIR-II FL imaging properties that facilitate the diagnosis of deep tissue diseases and provide the right time-point for PTT.

Hydrogen Therapy Reverses Cancer-Associated Fibroblasts Phenotypes and Remodels Stromal Microenvironment to Stimulate Systematic Anti-Tumor Immunity

Tumor microenvironment (TME) plays an important role in the tumor progression. Among TME components, cancer-associated fibroblasts (CAFs) show multiple tumor-promoting effects and can induce tumor immune evasion and drug-resistance. Regulating CAFs can be a potential strategy to augment systemic anti-tumor immunity. Here, the study observes that hydrogen treatment can alleviate intracellular reactive oxygen species of CAFs and reshape CAFs' tumor-promoting and immune-suppressive phenotypes. Accordingly, a controllable and TME-responsive hydrogen therapy based on a CaCO3 nanoparticles-coated magnesium system (Mg-CaCO3) is developed. The hydrogen therapy by Mg-CaCO3 can not only directly kill tumor cells, but also inhibit pro-tumor and immune suppressive factors in CAFs, and thus augment immune activities of CD4+ T cells. As implanted in situ, Mg-CaCO3 can significantly suppress tumor growth, turn the "cold" primary tumor into "hot", and stimulate systematic anti-tumor immunity, which is confirmed by the bilateral tumor transplantation models of "cold tumor" (4T1 cells) and "hot tumor" (MC38 cells). This hydrogen therapy system reverses immune suppressive phenotypes of CAFs, thus providing a systematic anti-tumor immune stimulating strategy by remodeling tumor stromal microenvironment.

Cryomicroneedle delivery of nanogold-engineered Rhodospirillum rubrum for photochemical transformation and tumor optical biotherapy

Tumor metabolite regulation is intricately linked to cancer progression. Because lactate is a characteristic metabolite of the tumor microenvironment (TME), it supports tumor progression and drives immunosuppression. In this study, we presented a strategy for antitumor therapy by developing a nanogold-engineered Rhodospirillum rubrum (R.r-Au) that consumed lactate and produced hydrogen for optical biotherapy. We leveraged a cryogenic micromolding approach to construct a transdermal therapeutic cryomicroneedles (CryoMNs) patch integrated with R.r-Au to efficiently deliver living bacterial drugs. Our long-term storage studies revealed that the viability of R.r-Au in CryoMNs remained above 90%. We found that the CryoMNs patch was mechanically strong and could be inserted into mouse skin. In addition, it rapidly dissolved after administering bacterial drugs and did not produce by-products. Under laser irradiation, R.r-Au effectively enhanced electron transfer through Au NPs actuation into the photosynthetic system of R. rubrum and enlarged lactate consumption and hydrogen production, thus leading to an improved tumor immune activation. Our study demonstrated the potential of CryoMNs-R.r-Au patch as a minimally invasive in situ delivery approach for living bacterial drugs. This research opens up new avenues for nanoengineering bacteria to transform tumor metabolites into effective substances for tumor optical biotherapy.

Optical Fiber-Enabled In Situ Photocatalytic Hydrogen Generation for Infiltrating Tumor Therapy in Brain

In addition to repressing proliferation, inhibiting the infiltration of tumor cells is an important strategy to improve the treatment of malignant tumors. Herein, a photocatalyst (pCNMC@Pt) is designed by sequentially assembling manganese dioxide, chlorin e6, and platinum (Pt) nanoparticles onto protonated graphitic carbon nitride. With the help of a Z-scheme structure and near-infrared (NIR) photosensitizer, pCNMC@Pt is capable of responding to NIR light to generate large amounts of hydrogen (H2). Taking lactic acid in the tumor microenvironment as a sacrificial reagent, H2 therapy initiated by the NIR photocatalyst remarkably impedes the growth of glioblastoma (GBM). More importantly, it is found that H2 can suppress the stemness of glioma stem cells, curbing both proliferation and infiltration of GBM. Furthermore, since pCNMC@Pt and light source are precisely co-localized through a self-built loading and illumination system, GBM in mouse brains can be efficiently treated, providing an alternative gas therapy approach to cure infiltrating tumors.

De novo design of a nanoregulator for the dynamic restoration of ovarian tissue in cryopreservation and transplantation

The cryopreservation and transplantation of ovarian tissue underscore its paramount importance in safeguarding reproductive capacity and ameliorating reproductive disorders. However, challenges persist in ovarian tissue cryopreservation and transplantation (OTC-T), including the risk of tissue damage and dysfunction. Consequently, there has been a compelling exploration into the realm of nanoregulators to refine and enhance these procedures. This review embarks on a meticulous examination of the intricate anatomical structure of the ovary and its microenvironment, thereby establishing a robust groundwork for the development of nanomodulators. It systematically categorizes nanoregulators and delves deeply into their functions and mechanisms, meticulously tailored for optimizing ovarian tissue cryopreservation and transplantation. Furthermore, the review imparts valuable insights into the practical applications and obstacles encountered in clinical settings associated with OTC-T. Moreover, the review advocates for the utilization of microbially derived nanomodulators as a potent therapeutic intervention in ovarian tissue cryopreservation. The progression of these approaches holds the promise of seamlessly integrating nanoregulators into OTC-T practices, thereby heralding a new era of expansive applications and auspicious prospects in this pivotal domain.

Mg alloys with antitumor and anticorrosion properties for orthopedic oncology: A review from mechanisms to application strategies

As a primary malignant bone cancer, osteosarcoma (OS) poses a great threat to human health and is still a huge challenge for clinicians. At present, surgical resection is the main treatment strategy for OS. However, surgical intervention will result in a large bone defect, and some tumor cells remaining around the excised bone tissue often lead to the recurrence and metastasis of OS. Biomedical Mg-based materials have been widely employed as orthopedic implants in bone defect reconstruction, and, especially, they can eradicate the residual OS cells due to the antitumor activities of their degradation products. Nevertheless, the fast corrosion rate of Mg alloys has greatly limited their application scope in the biomedical field, and the improvement of the corrosion resistance will impair the antitumor effects, which mainly arise from their rapid corrosion. Hence, it is vital to balance the corrosion resistance and the antitumor activities of Mg alloys. The presented review systematically discussed the potential antitumor mechanisms of three corrosion products of Mg alloys. Moreover, several strategies to simultaneously enhance the anticorrosion properties and antitumor effects of Mg alloys were also proposed.

Mesoporous carbon nanoparticles embedded with iron in hydrogen-photothermal synergistic therapy

We developed a new method to synthesize polyethylene glycol modified ultra small iron embedded in mesoporous carbon nanoparticle (C/Fe-PEG NP) for hydrogen (H2) assisted photothermal synergistic therapy. Herein, we use a simple in-situ reduction method to obtain the C/Fe NP in one-step carbonizing process, which is further modified by the biocompatible polyethylene glycol (PEG) on the surface of C/Fe NP to acquire high stability in physiological solutions. Utilizing the excellent photothermal property from the mesoporous carbon and the controllable H2 release property in the weakly acidic tumor microenvironment by the ultra-small Fe, the obtained C/Fe-PEG NPs can effective kill the cancer cells, meanwhile, protect normal cells without drugs. This selective anti-cancer mechanism of C/Fe-PEG NPs may because the produced H2 selective change the mitochondrial energy metabolism. In vivo results prove that the C/Fe-PEG NPs achieve excellent tumor ablation therapeutic effect and normal tissue protecting ability benefit from the H2-assisted photothermal therapy, promising the use of novel nanomaterials with more safety method for future cancer therapy.

Hydrogen therapy promotes macrophage polarization to the M2 subtype in radiation lung injury by inhibiting the NF-κB signalling pathway

Background

Radiotherapy has become a standard treatment for chest tumors, but a common complication of radiotherapy is radiation lung injury. Currently, there is still a lack of effective treatment for radiation lung injury.

Methods

A mouse model of radioactive lung injury (RILI) was constructed and then treated with different cycles of hydrogen inhalation. Lung function tests were performed to detect changes in lung function.HE staining was used to detect pathological changes in lung tissue. Immunofluorescence staining was used to detect the polarization of macrophages in lung tissue. Immunohistochemistry was used to detect changes in cytokine expression in lung tissues. Western Blot was used to detect the expression of proteins related to the NF-κB signalling pathway.

Results

Lung function test results showed that lung function decreased in the model group and improved in the treatment group.HE staining showed that inflammatory response was evident in the model group and decreased in the treatment group. Immunohistochemistry results showed that the expression of pro-inflammatory factors was significantly higher in the model group, and the expression of pro-inflammatory factors was significantly higher in the treatment group. The expression of pro-inflammatory factors in the treatment group was significantly lower than that in the model group, and the expression of anti-inflammatory factors in the treatment group was higher than that in the model group. Immunofluorescence showed that the expression of M1 subtype macrophages was up-regulated in the model group and down-regulated in the treatment group. The expression of M2 subtype macrophages was up-regulated in the treatment group relative to the model group. Western Blot showed that P-NF-κB p65/NF-κB p65 was significantly increased in the model group, and P-NF-κB p65/NF-κB p65 was decreased in the treatment group.

Conclusion

Hydrogen therapy promotes macrophage polarization from M1 to M2 subtypes by inhibiting the NF-κB signalling pathway, thereby attenuating the inflammatory response to radiation lung injury.

NIR-II Absorption/Emission Dual Function Based 2D Targeted Nanotheranostics for Tunable Hydrogenothermal Therapy

Photothermal therapy (PTT) is a promising approach for treating tumors that offers multiple advantages. Nevertheless, its practical use in clinical settings faces several limitations, such as suboptimal delivery efficiency, uneven heat distribution, and challenges in predicting optimal treatment duration. In addition, the localized hyperthermia generated by the PTT method to induce cell apoptosis can result in the production of excessive reactive oxygen species (ROS) and the release of inflammatory cytokines, which can pose a threat to the healthy tissues surrounding the tumor. To address the above challenges, this work designs an integrated H2 delivery nanoplatform for multimodal imaging H2 thermal therapy. The combination of the second near-infrared window (NIR-II) fluorescence imaging (FL) agent (CQ4T) and the photothermal and photoacoustic (PA) properties of Ti3C2 (TC) enables real-time monitoring of the tumor area and guides photothermal treatment. Simultaneously, due to the acid-responsive H2 release characteristics of the nanoplatform, H2 can be utilized for synergistic photothermal therapy to eradicate tumor cells effectively. Significantly, acting as an antioxidant and anti-inflammatory agent, Ti3C2-BSA-CQ4T-H2 (TCBCH) protects peritumoral normal cells from damage. The proposed technique utilizing H2 gas for combination therapies and multimodal imaging integration exhibits prospects for effective and secure treatment of tumors in future clinical applications.

Recent advances in the application of gasotransmitters in spinal cord injury

Spinal Cord Injury (SCI) is a condition characterized by complete or incomplete motor and sensory impairment, as well as dysfunction of the autonomic nervous system, caused by factors such as trauma, tumors, or inflammation. Current treatment methods primarily include traditional approaches like spinal canal decompression and internal fixation surgery, steroid pulse therapy, as well as newer techniques such as stem cell transplantation and brain-spinal cord interfaces. However, the above methods have limited efficacy in promoting axonal and neuronal regeneration. The challenge in medical research today lies in promoting spinal cord neuron regeneration and regulating the disrupted microenvironment of the spinal cord. Studies have shown that gas molecular therapy is increasingly used in medical research, with gasotransmitters such as hydrogen sulfide, nitric oxide, carbon monoxide, oxygen, and hydrogen exhibiting neuroprotective effects in central nervous system diseases. The gas molecular protect against neuronal death and reshape the microenvironment of spinal cord injuries by regulating oxidative, inflammatory and apoptotic processes. At present, gas therapy mainly relies on inhalation for systemic administration, which cannot effectively enrich and release gas in the spinal cord injury area, making it difficult to achieve the expected effects. With the rapid development of nanotechnology, the use of nanocarriers to achieve targeted enrichment and precise control release of gas at Sites of injury has become one of the emerging research directions in SCI. It has shown promising therapeutic effects in preclinical studies and is expected to bring new hope and opportunities for the treatment of SCI. In this review, we will briefly outline the therapeutic effects and research progress of gasotransmitters and nanogas in the treatment of SCI.

Hydrogen gas inhalation ameliorates LPS-induced BPD by inhibiting inflammation via regulating the TLR4-NFκB-IL6/NLRP3 signaling pathway in the placenta

INTRODUCTION

Hydrogen (H2) is regarded as a novel therapeutic agent against several diseases owing to its inherent biosafety. Bronchopulmonary dysplasia (BPD) has been widely considered among adverse pregnancy outcomes, without effective treatment. Placenta plays a role in defense, synthesis, and immunity, which provides a new perspective for the treatment of BPD. This study aimed to investigate if H2 reduced the placental inflammation to protect the neonatal rat against BPD damage and potential mechanisms.

METHODS

We induced neonatal BPD model by injecting lipopolysaccharide (LPS, 1 µg) into the amniotic fluid at embryonic day 16.5 as LPS group. LPS + H2 group inhaled 42% H2 gas (4 h/day) until the samples were collected. We primarily analyzed the neonatal outcomes and then compared inflammatory levels from the control group (CON), LPS group and LPS + H2 group. HE staining was performed to evaluate inflammatory levels. RNA sequencing revealed dominant differentially expressed genes. Bioinformatics analysis (GO and KEGG) of RNA-seq was applied to mine the signaling pathways involved in protective effect of H2 on the development of LPS-induced BPD. We further used qRT-PCR, Western blot and ELISA methods to verify differential expression of mRNA and proteins. Moreover, we verified the correlation between the upstream signaling pathways and the downstream targets in LPS-induced BPD model.

RESULTS

Upon administration of H2, the inflammatory infiltration degree of the LPS-induced placenta was reduced, and infiltration significantly narrowed. Hydrogen normalized LPS-induced perturbed lung development and reduced the death ratio of the fetus and neonate. RNA-seq results revealed the importance of inflammatory response biological processes and Toll-like receptor signaling pathway in protective effect of hydrogen on BPD. The over-activated upstream signals [Toll-like receptor 4 (TLR4), nuclear factor kappa-B p65 (NF-κB p65), Caspase1 (Casp1) and NLR family pyrin domain containing 3 (NLRP3) inflammasome] in LPS placenta were attenuated by H2 inhalation. The downstream targets, inflammatory cytokines/chemokines [interleukin (IL)-6, IL-18, IL-1β, C-C motif chemokine ligand 2 (CCL2) and C-X-C motif chemokine ligand 1 (CXCL1)], were decreased both in mRNA and protein levels by H2 inhalation in LPS-induced placentas to rescue them from BPD. Correlation analysis displayed a positive association of TLR4-mediated signaling pathway both proinflammatory cytokines and chemokines in placenta.

CONCLUSION

H2 inhalation ameliorates LPS-induced BPD by inhibiting excessive inflammatory cytokines and chemokines via the TLR4-NFκB-IL6/NLRP3 signaling pathway in placenta and may be a potential therapeutic strategy for BPD.

In Situ Piezoelectric-Catalytic Anti-Inflammation Promotes the Rehabilitation of Acute Spinal Cord Injury in Synergy

Relieving inflammation via scavenging toxic reactive oxygen species (ROS) during the acute phase of spinal cord injury (SCI) proves to be an effective strategy to mitigate secondary spinal cord injury and improve recovery of motor function. However, commonly used corticosteroid anti-inflammatory drugs show adverse side effects which may induce increased risk of wound infection. Fortunately, hydrogen (H2), featuring selective antioxidant performance, easy penetrability, and excellent biosafety, is being extensively investigated as a potential anti-inflammatory therapeutic gas for the treatment of SCI. In this work, by a facile in situ growth approach of gold nanoparticles (AuNPs) on the piezoelectric BaTiO3, a particulate nanocomposite with Schottky heterojunction (Au@BT) is synthesized, which can generate H2 continuously by catalyzing H+ reduction through piezoelectric catalysis. Further, theoretical calculations are employed to reveal the piezoelectric catalytic mechanism of Au@BT. Transcriptomics analysis and nontargeted large-scale metabolomic analysis reveal the deeper mechanism of the neuroprotective effect of H2 therapy. The as-prepared Au@BT nanoparticle is first explored as a flexible hydrogen gas generator for efficient SCI therapy. This study highlights a promising prospect of nanocatalytic medicine for disease treatments by catalyzing H2 generation; thus, offering a significant alternative to conventional approaches against refractory spinal cord injury.

Nanomaterials-Induced Redox Imbalance: Challenged and Opportunities for Nanomaterials in Cancer Therapy

Cancer cells typically display redox imbalance compared with normal cells due to increased metabolic rate, accumulated mitochondrial dysfunction, elevated cell signaling, and accelerated peroxisomal activities. This redox imbalance may regulate gene expression, alter protein stability, and modulate existing cellular programs, resulting in inefficient treatment modalities. Therapeutic strategies targeting intra- or extracellular redox states of cancer cells at varying state of progression may trigger programmed cell death if exceeded a certain threshold, enabling therapeutic selectivity and overcoming cancer resistance to radiotherapy and chemotherapy. Nanotechnology provides new opportunities for modulating redox state in cancer cells due to their excellent designability and high reactivity. Various nanomaterials are widely researched to enhance highly reactive substances (free radicals) production, disrupt the endogenous antioxidant defense systems, or both. Here, the physiological features of redox imbalance in cancer cells are described and the challenges in modulating redox state in cancer cells are illustrated. Then, nanomaterials that regulate redox imbalance are classified and elaborated upon based on their ability to target redox regulations. Finally, the future perspectives in this field are proposed. It is hoped this review provides guidance for the design of nanomaterials-based approaches involving modulating intra- or extracellular redox states for cancer therapy, especially for cancers resistant to radiotherapy or chemotherapy, etc.

Prospects of molecular hydrogen in cancer prevention and treatment

Gas signaling molecules, including carbon monoxide (CO), nitric oxide (NO), and hydrogen sulfide (H2S), have been shown to have cancer therapeutic potential, pointing to a new direction for cancer treatment. In recent years, a series of studies have confirmed that hydrogen (H2), a weakly reductive gas, also has therapeutic effects on various cancers and can mitigate oxidative stress caused by radiation and chemotherapy, reducing tissue damage and immunosuppression to improve prognosis. Meanwhile, H2 also has immunomodulatory effects, inhibiting T cell exhaustion and enhancing T cell anti-tumor function. It is worth noting that human intestinal flora can produce large amounts of H2 daily, which becomes a natural barrier to maintaining the body's resistance to diseases such as tumors. Although the potential anti-tumor mechanisms of H2 are still to be investigated, previous studies have shown that H2 can selectively scavenge highly toxic reactive oxygen species (ROS) and inhibit various ROS-dependent signaling pathways in cancer cells, thus inhibiting cancer cell proliferation and metastasis. The ROS scavenging ability of H2 may also be the underlying mechanism of its immunomodulatory function. In this paper, we review the significance of H2 produced by intestinal flora on the immune homeostasis of the body, the role of H2 in cancer therapy and the underlying mechanisms, and the specific application of H2 to provide new ideas for the comprehensive treatment of cancer patients.

Microfluidic Synthesis of CuH Nanoparticles for Antitumor Therapy through Hydrogen-Enhanced Apoptosis and Cuproptosis

Cuproptosis has drawn enormous attention in antitumor material fields; however, the responsive activation of cuproptosis against tumors using nanomaterials with high atom utilization is still challenging. Herein, a copper-based nanoplatform consisting of acid-degradable copper hydride (CuH) nanoparticles was developed via a microfluidic synthesis. After coating with tumor-targeting hyaluronic acid (HA), the nanoplatform denoted as HA-CuH-PVP (HCP) shows conspicuous damage toward tumor cells by generating Cu+ and hydrogen (H2) simultaneously. Cu+ can induce apoptosis by relying on Fenton-like reactions and lead to cuproptosis by causing mitochondrial protein aggregation. Besides, the existence of H2 can enhance both cell death types by causing mitochondrial dysfunction and intracellular redox homeostatic disorders. In vivo experimental results further exhibit the desirable potential of HCP for killing tumor cells and inhibiting lung metastases, which will broaden the horizons of designing copper-based materials triggering apoptosis and cuproptosis for better antitumor efficacy.

Recent Advances in Metal-Hydride-Based Disease Treatment

In comparison to traditional antioxidant treatment methods, the use of hydrogen to eliminate reactive oxygen species from the body has the advantages of high biological safety, strong selectivity, and high clearance rate. As an energy storage material, metal hydrides have been extensively studied and used in transporting hydrogen as clean energy, which can achieve a high hydrogen load and controlled hydrogen release. Considering the antioxidant properties of hydrogen and the delivery ability of metal hydrides, metal-hydride-based disease treatment strategies have attracted widespread attention. Up to now, metal hydrides have been reported for the treatment of tumors and a range of inflammation-related diseases. However, limited by the insufficient investment, the use of metal hydrides in disease treatment still has many shortcomings, such as low targeting efficiency, limited therapeutic activity, and complex material preparation process. Particularly, metal hydrides have been found to have a series of optical, acoustic, and catalytic properties when scaled up to the nanoscale, and these properties are also widely used to promote disease treatment effects. From this new perspective, we comprehensively summarize the very recent research progress on metal-hydride-based disease treatment in this review. Ultimately, the challenges and prospects of such a burgeoning cancer theranostics modality are outlooked to provide inspiration for the further development and clinical translation of metal hydrides.

NIR-Activatable Heterostructured Nanoadjuvant CoP/NiCoP Executing Lactate Metabolism Interventions for Boosted Photocatalytic Hydrogen Therapy and Photoimmunotherapy

Near-infrared (NIR) laser-induced photoimmunotherapy has aroused great interest due to its intrinsic noninvasiveness and spatiotemporal precision, while immune evasion evoked by lactic acid (LA) accumulation severely limits its clinical outcomes. Although several metabolic interventions have been devoted to ameliorate immunosuppression, intracellular residual LA still remains a potential energy source for oncocyte proliferation. Herein, an immunomodulatory nanoadjuvant based on a yolk-shell CoP/NiCoP (CNCP) heterostructure loaded with the monocarboxylate transporter 4 inhibitor fluvastatin sodium (Flu) is constructed to concurrently relieve immunosuppression and elicit robust antitumor immunity. Under NIR irradiation, CNCP heterojunctions exhibit superior photothermal performance and photocatalytic production of reactive oxygen species and hydrogen. The continuous heat then facilitates Flu release to restrain LA exudation from tumor cells, whereas cumulative LA can be depleted as a hole scavenger to improve photocatalytic efficiency. Subsequently, potentiated photocatalytic therapy can not only initiate systematic immunoreaction, but also provoke severe mitochondrial dysfunction and disrupt the energy supply for heat shock protein synthesis, in turn realizing mild photothermal therapy. Consequently, LA metabolic remodeling endows an intensive cascade treatment with an optimal safety profile to effectually suppress tumor proliferation and metastasis, which offers a new paradigm for the development of metabolism-regulated immunotherapy.

Application of nanotechnology in the treatment of glomerulonephritis: current status and future perspectives

Glomerulonephritis (GN) is the most common cause of end-stage renal failure worldwide; in most cases, it cannot be cured and can only delay the progression of the disease. At present, the main treatment methods include symptomatic therapy, immunosuppressive therapy, and renal replacement therapy. However, effective treatment of GN is hindered by issues such as steroid resistance, serious side effects, low bioavailability, and lack of precise targeting. With the widespread application of nanoparticles in medical treatment, novel methods have emerged for the treatment of kidney diseases. Targeted transportation of drugs, nucleic acids, and other substances to kidney tissues and even kidney cells through nanodrug delivery systems can reduce the systemic effects and adverse reactions of drugs and improve treatment effectiveness. The high specificity of nanoparticles enables them to bind to ion channels and block or enhance channel gating, thus improving inflammation. This review briefly introduces the characteristics of GN, describes the treatment status of GN, systematically summarizes the research achievements of nanoparticles in the treatment of primary GN, diabetic nephropathy and lupus nephritis, analyzes recent therapeutic developments, and outlines promising research directions, such as gas signaling molecule nanodrug delivery systems and ultrasmall nanoparticles. The current application of nanoparticles in GN is summarized to provide a reference for better treatment of GN in the future.

The Therapeutic Application of Hydrogen in Cancer: The Potential and Challenges

Hydrogen therapy has emerged as a possible approach for both preventing and treating cancer. Cancers are often associated with oxidative stress and chronic inflammation. Hydrogen, with its unique physiological functions and characteristics, exhibits antioxidant, anti-inflammatory, and anti-apoptotic properties, making it an attractive candidate for cancer treatment. Through its ability to mitigate oxidative damage, modulate inflammatory responses, and sustain cellular viability, hydrogen demonstrates significant potential in preventing cancer recurrence and improving treatment outcomes. Preclinical studies have shown the efficacy of hydrogen therapy in several cancer types, highlighting its ability to enhance the effectiveness of conventional treatments while reducing associated side effects. Furthermore, hydrogen therapy has been found to be safe and well-tolerated in clinical settings. Nonetheless, additional investigations are necessary to improve a comprehensive understanding of the mechanisms underlying hydrogen's therapeutic potential and refine the administration and dosage protocols. However, further clinical trials are still needed to explore its safety profile and capacity. In aggregate, hydrogen therapy represents an innovative and promising treatment for several malignancies.

pH-Responsive Injectable Multifunctional Pluronic F127/Gelatin-Based Hydrogels with Hydrogen Production for Treating Diabetic Wounds

Diabetic chronic wounds remain a major clinical challenge with long-term inflammatory responses and extreme oxidative damage. Hence, a pH-responsive injectable multifunctional hydrogel [Gel/CUR-FCHO/Mg (GCM) micromotors] via a Schiff base reaction between gelatin and benzaldehyde-grafted Pluronic F127 drug-loaded micelles (FCHO) was fabricated for the first time. Dynamic Schiff base linkage endowed the GCM hydrogel with the ability to be self-healing, injectable, and pH-responsive for on-demand drug delivery at the wound site. Curcumin (CUR), a hydrophobic drug with antioxidative, anti-inflammatory, and antibacterial activities, was encapsulated into the hydrogel matrix by micellization (CUR-FCHO micelles). Simultaneously, magnesium-based micromotors (Mg micromotors) were physically entrapped into the system for providing active hydrogen (H2) to scavenge reactive oxygen species and alleviate inflammatory responses. As a result, the GCM micromotor hydrogel displayed an inherent antibacterial property, extraordinary antioxidative performance, and remarkable biocompatibility. In the diabetic mouse with a full-thickness cutaneous defect wound, the GCM hydrogel could remodel the inflammatory microenvironment and stimulate vascularization and collagen deposition, thereby facilitating wound closure and enhancing tissue regeneration, which offered a promising therapeutic option for diabetic chronic wound management.

The role of hydrogen therapy in Alzheimer's disease management: Insights into mechanisms, administration routes, and future challenges

Alzheimer's disease (AD) is a progressive neurodegenerative disorder predominantly affecting the elderly. While conventional pharmacological therapies remain the primary treatment for AD, their efficacy is limited effectiveness and often associated with significant side effects. This underscores the urgent need to explore alternative, non-pharmacological interventions. Oxidative stress has been identified as a central player in AD pathology, influencing various aspects including amyloid-beta metabolism, tau phosphorylation, autophagy, neuroinflammation, mitochondrial dysfunction, and synaptic dysfunction. Among the emerging non-drug approaches, hydrogen therapy has garnered attention for its potential in mitigating these pathological conditions. This review provides a comprehensively overview of the therapeutic potential of hydrogen in AD. We delve into its mechanisms of action, administration routes, and discuss the current challenges and future prospects, with the aim of providing valuable insights to facilitate the clinical application of hydrogen-based therapies in AD management.

Nanoreactor-based catalytic systems for therapeutic applications: Principles, strategies, and challenges

Inspired by natural catalytic compartments, various synthetic compartments that seclude catalytic reactions have been developed to understand complex multistep biosynthetic pathways, bestow therapeutic effects, or extend biosynthetic pathways in living cells. These emerging nanoreactors possessed many advantages over conventional biomedicine, such as good catalytic activity, specificity, and sustainability. In the past decade, a great number of efficient catalytic systems based on diverse nanoreactors (polymer vesicles, liposome, polymer micelles, inorganic-organic hybrid materials, MOFs, etc.) have been designed and employed to initiate in situ catalyzed chemical reactions for therapy. This review aims to present the recent progress in the development of catalytic systems based on nanoreactors for therapeutic applications, with a special emphasis on the principles and design strategies. Besides, the key components of nanoreactor-based catalytic systems, including nanocarriers, triggers or energy inputs, and products, are respectively introduced and discussed in detail. Challenges and prospects in the fabrication of therapeutic catalytic nanoreactors are also discussed as a conclusion to this review. We believe that catalytic nanoreactors will play an increasingly important role in modern biomedicine, with improved therapeutic performance and minimal side effects.

Recent Developments in Metallic Degradable Micromotors for Biomedical and Environmental Remediation Applications

Synthetic micromotor has gained substantial attention in biomedicine and environmental remediation. Metal-based degradable micromotor composed of magnesium (Mg), zinc (Zn), and iron (Fe) have promise due to their nontoxic fuel-free propulsion, favorable biocompatibility, and safe excretion of degradation products Recent advances in degradable metallic micromotor have shown their fast movement in complex biological media, efficient cargo delivery and favorable biocompatibility. A noteworthy number of degradable metal-based micromotors employ bubble propulsion, utilizing water as fuel to generate hydrogen bubbles. This novel feature has projected degradable metallic micromotors for active in vivo drug delivery applications. In addition, understanding the degradation mechanism of these micromotors is also a key parameter for their design and performance. Its propulsion efficiency and life span govern the overall performance of a degradable metallic micromotor. Here we review the design and recent advancements of metallic degradable micromotors. Furthermore, we describe the controlled degradation, efficient in vivo drug delivery, and built-in acid neutralization capabilities of degradable micromotors with versatile biomedical applications. Moreover, we discuss micromotors' efficacy in detecting and destroying environmental pollutants. Finally, we address the limitations and future research directions of degradable metallic micromotors.

Bridging the Gap-Thermofluidic Designs for Precision Bioelectronics

Bioelectronics, the merging of biology and electronics, can monitor and modulate biological behaviors across length and time scales with unprecedented capability. Current bioelectronics research largely focuses on devices' mechanical properties and electronic designs. However, the thermofluidic control is often overlooked, which is noteworthy given the discipline's importance in almost all bioelectronics processes. It is believed that integrating thermofluidic designs into bioelectronics is essential to align device precision with the complexity of biofluids and biological structures. This perspective serves as a mini roadmap for researchers in both fields to introduce key principles, applications, and challenges in both bioelectronics and thermofluids domains. Important interdisciplinary opportunities for the development of future healthcare devices and precise bioelectronics will also be discussed.

Application of hyaluronic acid-based nanoparticles for cancer combination therapy

Cancer is a significant public health problem in the world. The treatment methods include surgery, chemotherapy, phototherapy, and immunotherapy. Due to their respective limitations, the treatment effect is often unsatisfactory, laying hidden dangers for metastasis and recurrence. Since their exceptional biocompatibility and excellent targeting capabilities, hyaluronic acid-based biomaterials have generated great interest as drug delivery methods for tumor therapy. Moreover, modified HA can self-assemble into hydrogels or nanoparticles (NPs) for precise drug administration. This article summarizes the application of HA-based NPs in combination therapy. Ultimately, it is anticipated that this research will offer guidance for creating various HA-based NPs utilized in numerous cancer therapies.

The efficacy of hydrogen/oxygen therapy favored the recovery of omicron SARS-CoV-2 variant infection: results of a multicenter, randomized, controlled trial

Clinical studies had found that hydrogen/oxygen mixed inhalation was beneficial to ameliorate the respiratory symptoms in the adjuvant treatment of patients with COVID-19. We aimed to explore the efficacy of hydrogen/oxygen therapy in favoring the recovery of Omicron SARS-CoV-2 variant infection. There were 64 patients who randomly assigned to receive hydrogen/oxygen inhalation (32 patients) and oxygen inhalation (32 patients). The average shedding duration of Omicron in hydrogen/oxygen group was shorter than oxygen group. The trend of cumulative negative conversion rate of Omicron increased gradually after the third day. The IL-6 levels in hydrogen/oxygen group decreased by 22.8% compared with the baseline. After hydrogen/oxygen mixed gas inhalation, the lymphocyte count increased to 61.1% of the baseline on the 3rd day in the hydrogen/oxygen group. More patients in the hydrogen/oxygen group had resolution of pulmonary lesions. Our study showed the beneficial trends of molecular hydrogen in treating patients with COVID-19, which may offer a prospective solution to adjuvant therapy for COVID-19 Patients.

Cu2+ -Anchored Carbon Nano-Photocatalysts for Visible Water Splitting to Boost Hydrogen Cuproptosis

Both hydrogen (H2 ) and copper ions (Cu+ ) can be used as anti-cancer treatments. However, the continuous generation of H2 molecules and Cu+ in specific sites of tumors is challenging. Here we anchored Cu2+ on carbon photocatalyst (Cu@CDCN) to allow the continuous generation of H2 and hydrogen peroxide (H2 O2 ) in tumors using the two-electron process of visible water splitting. The photocatalytic process also generated redox-active Cu-carbon centers. Meanwhile, the Cu2+ residues reacted with H2 O2 (the obstacle to the photocatalytic process) to accelerate the two-electron process of water splitting and cuprous ion (Cu+ ) generation, in which the Cu2+ residue promoted a pro-oxidant effect with glutathione through metal-reducing actions. Both H2 and Cu+ induced mitochondrial dysfunction and intracellular redox homeostasis destruction, which enabled hydrogen therapy and cuproptosis to inhibit cancer cell growth and suppress tumor growth. Our research is the first attempt to integrate hydrogen therapy and cuproptosis using metal-enhanced visible solar water splitting in nanomedicine, which may provide a safe and effective cancer treatment.

Nanomedicine innovations in spinal cord injury management: Bridging the gap

Spinal cord injury (SCI) has devastating effects on a person's physical, social, and professional well-being. It is a life-altering neurological condition that significantly impacts individuals and their caregivers on a socioeconomic level. Recent advancements in medical therapy have greatly improved the diagnosis, stability, survival rates, and overall well-being of SCI patients. However, there are still limited options available for enhancing neurological outcomes in these patients. The complex pathophysiology of SCI, along with the numerous biochemical and physiological changes that occur in the damaged spinal cord, contribute to this gradual improvement. Currently, there are no therapies that offer the possibility of recovery for SCI, although several therapeutic approaches are being developed. However, these therapies are still in the early stages and have not yet demonstrated effectiveness in repairing the damaged fibers, which hinders cellular regeneration and the full restoration of motor and sensory functions. Considering the importance of nanotechnology and tissue engineering in treating neural tissue injuries, this review focuses on the latest advancements in nanotechnology for SCI therapy and tissue healing. It examines research articles from the PubMed database that specifically address SCI in the field of tissue engineering, with an emphasis on nanotechnology as a therapeutic approach. The review evaluates the biomaterials used for treating this condition and the techniques employed to create nanostructured biomaterials.

A drug co-delivery platform made of magnesium-based micromotors enhances combination therapy for hepatoma carcinoma cells

Combination therapy is an emerging strategy to overcome multidrug resistance (MDR) in hepatocellular carcinoma (HCC) chemotherapy treatment. However, the passive diffusion in traditional delivery systems greatly retards the approach and penetration of drugs into hepatocellular carcinoma cells and thus hinders the efficacy of combination therapy. Micro/nanomotors with autonomous locomotion in a tiny scale provide the possibility of tackling this issue. Herein, an active drug delivery micromotor platform delicately designed to load drugs with different physicochemical properties and enhance the drug permeability of cells is demonstrated for HCC chemotherapy treatment. The biocompatible micromotor platform Mg/PLGA/CHI comprised magnesium (Mg) coated with two polymer layers made of poly(lactic-co-glycolic acid) (PLGA) and chitosan (CHI), where the hydrophobic and hydrophilic drugs doxorubicin (Dox) and Curcumin (Cur) were loaded, respectively. The autonomous motion of the micromotors with velocity up to 45 μm s-1 greatly enhanced the diffusion of chemotherapeutic drugs and led to higher extracellular and intracellular drug distribution. Moreover, hydrogen produced during the motion eliminated the excess reactive oxygen species (ROS) in the human hepatocellular carcinoma (HepG2) cells. Compared with inert groups, the absorption of Dox and Cur from the active micromotors was about 2.9 and 1.5 times higher in human hepatocellular carcinoma (HepG2) cells. In addition, the anti-tumor activity also obviously improved at the micromotor concentration of 1 mg mL-1 (cell proliferation was reduced by almost 30%). Overall, this work proposes an approach based on loading different chemotherapy agents on an active delivery system to enhance drug permeability and overcome MDR and provides a potentially effective therapeutic strategy for the treatment of HCC.

Mechanisms and Application of Gas-Based Anticancer Therapies

Cancer is still one of the major factors threatening public health, with morbidity and mortality rates at the forefront of the world. Clinical drawbacks, such as high toxicity and side effects of drug therapy, and easy recurrence after surgery affect its therapeutic effect. Gas signaling molecules are essential in maintaining biological homeostasis and physiological functions as specific chemical substances for biological information transfer. In recent years, the physiological regulatory functions of gas molecules in the cancer process have been gradually revealed and have shown broad application prospects in tumor therapy. In this paper, standard gas therapies are classified and introduced. Taking H2, CO2, NO, CO, H2S, and SO2 gases as examples, the research progress and application of gas therapies in malignant tumors are mainly introduced in terms of biological characteristics, anticancer mechanisms, and treatment strategies. Finally, the problems and prospects for developing gases as anticancer drugs are outlined.

Photothermal-Triggered Sulfur Oxide Gas Therapy Augments Type I Photodynamic Therapy for Potentiating Cancer Stem Cell Ablation and Inhibiting Radioresistant Tumor Recurrence

Despite advances in cancer therapy, the existence of self-renewing cancer stem cells (CSC) can lead to tumor recurrence and radiation resistance, resulting in treatment failure and high mortality in patients. To address this issue, a near-infrared (NIR) laser-induced synergistic therapeutic platform has been developed by incorporating aggregation-induced emission (AIE)-active phototheranostic agents and sulfur dioxide (SO2 ) prodrug into a biocompatible hydrogel, namely TBH, to suppress malignant CSC growth. Outstanding hydroxyl radical (·OH) generation and photothermal effect of the AIE phototheranostic agent actualizes Type I photodynamic therapy (PDT) and photothermal therapy through 660 nm NIR laser irradiation. Meanwhile, a large amount of SO2 is released from the SO2 prodrug in thermo-sensitive TBH gel, which depletes upregulated glutathione in CSC and consequentially promotes ·OH generation for PDT enhancement. Thus, the resulting TBH hydrogel can diminish CSC under 660 nm laser irradiation and finally restrain tumor recurrence after radiotherapy (RT). In comparison, the tumor in the mice that were only treated with RT relapsed rapidly. These findings reveal a double-boosting ·OH generation protocol, and the synergistic combination of AIE-mediated PDT and gas therapy provides a novel strategy for inhibiting CSC growth and cancer recurrence after RT, which presents great potential for clinical treatment.

Space Station-like Composite Nanoparticles for Co-Delivery of Multiple Natural Compounds from Chinese Medicine and Hydrogen in Combating Sensorineural Hearing Loss

Ototoxic drugs such as aminoglycoside antibiotics and cisplatin (CDDP) can cause sensorineural hearing loss (SNHL), which is closely related to oxidative stress and the acidification of the inner ear microenvironment. Effective treatment of SNHL often requires multifaceted approach due to the complex pathology, and drug combination therapy is expected to be at the forefront of modern hearing loss treatment. Here, space-station-like composite nanoparticles (CCC@mPP NPs) with pH/oxidation dual responsiveness and multidrug simultaneous delivery capability were constructed and then loaded with various drugs including panax notoginseng saponins (PNS), tanshinone IIA (TSIIA), and ammonia borane (AB) to provide robust protection against SNHL. Molecular dynamics simulation revealed that carboxymethyl chitosan/calcium carbonate-chitosan (CCC) NPs and monomethoxy poly(ethylene glycol)-PLGA (mPP) NPs can rendezvous and dock primarily by hydrogen bonding, and electrostatic forces may be involved. Moreover, CCC@mPP NPs crossed the round window membrane (RWM) and entered the inner ear through endocytosis and paracellular pathway. The docking state was basically maintained during this process, which created favorable conditions for multidrug delivery. This nanosystem was highly sensitive to pH and reactive oxygen species (ROS) changes, as evidenced by the restricted release of payload at alkaline condition (pH 7.4) without ROS, while significantly promoting the release in acidic condition (pH 5.0 and 6.0) with ROS. TSIIA/PNS/AB-loaded CCC@mPP NPs almost completely preserved the hair cells and remained the hearing threshold shift within normal limits in aminoglycoside- or CDDP-treated guinea pigs. Further experiments demonstrated that the protective mechanisms of TSIIA/PNS/AB-loaded CCC@mPP NPs involved direct and indirect scavenging of excessive ROS, and reduced release of pro-inflammatory cytokines. Both in vitro and in vivo experiments showed the high biocompatibility of the composite NPs, even after long-term administration. Collectively, this work suggests that composite NPs is an ideal multi-drug-delivery vehicle and open new avenues for inner ear disease therapies.

Magnesium implant degradation provides immunomodulatory and proangiogenic effects and attenuates peri-implant fibrosis in soft tissues

Implants made of magnesium (Mg) are increasingly employed in patients to achieve osteosynthesis while degrading in situ. Since Mg implants and Mg²⁺ have been suggested to possess anti-inflammatory properties, the clinically observed soft tissue inflammation around Mg implants is enigmatic. Here, using a rat soft tissue model and a 1-28 d observation period, we determined the temporo-spatial cell distribution and behavior in relation to sequential changes of pure Mg implant surface properties and Mg²⁺ release. Compared to nondegradable titanium (Ti) implants, Mg degradation exacerbated initial inflammation. Release of Mg degradation products at the tissue-implant interface, culminating at 3 d, actively initiated chemotaxis and upregulated mRNA and protein immunomodulatory markers, particularly inducible nitric oxide synthase and toll-like receptor-4 up to 6 d, yet without a cytotoxic effect. Increased vascularization was demonstrated morphologically, preceded by high expression of vascular endothelial growth factor. The transition to appropriate tissue repair coincided with implant surface enrichment of Ca and P and reduced peri-implant Mg²⁺ concentration. Mg implants revealed a thinner fibrous encapsulation compared with Ti. The detailed understanding of the relationship between Mg material properties and the spatial and time-resolved cellular processes provides a basis for the interpretation of clinical observations and future tailoring of Mg implants.

Cancer phototherapy with nano-bacteria biohybrids

The utilization of light for therapeutic interventions, also known as phototherapy, has been extensively employed in the treatment of a wide range of illnesses, including cancer. Despite the benefits of its non-invasive nature, phototherapy still faces challenges pertaining to the delivery of phototherapeutic agents, phototoxicity, and light delivery. The incorporation of nanomaterials and bacteria in phototherapy has emerged as a promising approach that leverages the unique properties of each component. The resulting nano-bacteria biohybrids exhibit enhanced therapeutic efficacy when compared to either component individually. In this review, we summarize and discuss the various strategies for assembling nano-bacteria biohybrids and their applications in phototherapy. We provide a comprehensive overview of the properties and functionalities of nanomaterials and cells in the biohybrids. Notably, we highlight the roles of bacteria beyond their function as drug vehicles, particularly their capacity to produce bioactive molecules. Despite being in its early stage, the integration of photoelectric nanomaterials and genetically engineered bacteria holds promise as an effective biosystem for antitumor phototherapy. The utilization of nano-bacteria biohybrids in phototherapy is a promising avenue for future investigation, with the potential to enhance treatment outcomes for cancer patients.

A liquid metal dressing for anti-inflammatory and anti-infection applications to treat diabetic wounds

We report a dual-effect liquid metal dressing with antibiotic delivery and hydrogen generation capacity for antibacterial and anti-inflammatory applications. This material provides a gentle approach for H₂ therapy and responsive drug delivery, and can treat chronic diabetic wounds.

Hydrogen Attenuates Inflammation by Inducing Early M2 Macrophage Polarization in Skin Wound Healing

The heterogeneous and highly plastic cell populations of macrophages are important mediators of cellular responses during all stages of wound healing, especially in the inflammatory stage. Molecular hydrogen (H₂), which has potent antioxidant and anti-inflammatory effects, has been shown to promote M2 polarization in injury and disease. However, more in vivo time series studies of the role of M1-to-M2 polarization in wound healing are needed. In the current study, we performed time series experiments on a dorsal full-thickness skin defect mouse model in the inflammatory stage to examine the effects of H₂ inhalation. Our results revealed that H₂ could promote very early M1-to-M2 polarization (on days 2-3 post wounding, 2-3 days earlier than in conventional wound healing), without disturbing the functions of the M1 phenotype. Time series analysis of the transcriptome, blood cell counts, and multiple cytokines further indicated that peripheral blood monocytes were a source of H₂-induced M2 macrophages and that the functions of H₂ in macrophage polarization were not only dependent on its antioxidant effects. Therefore, we believe that H₂ could reduce inflammation in wound care by shifting early macrophage polarization in clinical settings.

Flexible Monitoring, Diagnosis, and Therapy by Microneedles with Versatile Materials and Devices toward Multifunction Scope

Microneedles (MNs) have drawn rising attention owing to their merits of convenience, noninvasiveness, flexible applicability, painless microchannels with boosted metabolism, and precisely tailored multifunction control. MNs can be modified to serve as novel transdermal drug delivery, which conventionally confront with the penetration barrier caused by skin stratum corneum. The micrometer-sized needles create channels through stratum corneum, enabling efficient drug delivery to the dermis for gratifying efficacy. Then, incorporating photosensitizer or photothermal agents into MNs can conduct photodynamic or photothermal therapy, respectively. Besides, health monitoring and medical detection by MN sensors can extract information from skin interstitial fluid and other biochemical/electronic signals. Here, this review discloses a novel monitoring, diagnostic, and therapeutic pattern by MNs, with elaborate discussion about the classified formation of MNs together with various applications and inherent mechanism. Hereby, multifunction development and outlook from biomedical/nanotechnology/photoelectric/devices/informatics to multidisciplinary applications are provided. Programmable intelligent MNs enable logic encoding of diverse monitoring and treatment pathways to extract signals, optimize the therapy efficacy, real-time monitoring, remote control, and drug screening, and take instant treatment.

Molecular Hydrogen: an Emerging Therapeutic Medical Gas for Brain Disorders

Oxidative stress and neuroinflammation are the main physiopathological changes involved in the initiation and progression of various neurodegenerative disorders or brain injuries. Since the landmark finding reported in 2007 found that hydrogen reduced the levels of peroxynitrite anions and hydroxyl free radicals in ischemic stroke, molecular hydrogen's antioxidative and anti-inflammatory effects have aroused widespread interest. Due to its excellent antioxidant and anti-inflammatory properties, hydrogen therapy via different routes of administration exhibits great therapeutic potential for a wide range of brain disorders, including Alzheimer's disease, neonatal hypoxic-ischemic encephalopathy, depression, anxiety, traumatic brain injury, ischemic stroke, Parkinson's disease, and multiple sclerosis. This paper reviews the routes for hydrogen administration, the effects of hydrogen on the previously mentioned brain disorders, and the primary mechanism underlying hydrogen's neuroprotection. Finally, we discuss hydrogen therapy's remaining issues and challenges in brain disorders. We conclude that understanding the exact molecular target, finding novel routes, and determining the optimal dosage for hydrogen administration is critical for future studies and applications.

Imaging Guided Endogenic H2 -Augmented Electrochemo-Sonodynamic Domino Co-therapy of Tumor in Vivo

Precise and on-demand release of sufficient hydrogen (H₂ ) to tumor sites remains a key challenge for emerging H₂ -oncotherapy, and little is known about the physiological effects of "abundant" H₂ on complex tumor microenvironments (TME). Here, a highly efficient and cost-effective imaging-guided/-assessed H₂ -therapy of tumors based on a joint electrochemo-sonodynamic treatment (H₂ -EC/SD co-therapy) with strong "domino effect" triggered by endogenous H₂ generation at tumor sites is reported to speedily eliminate tumor tissue (≤80 mm³ ) within 1 day. Adequate H₂ is controllably generated in tumor sites through mild electrochemistry in vivo due to acidic TME by using clinical acupuncture Fe needles as electrodes. Besides starvation damage due to gas blockage/destruction of vessels, nano-/micro-bubbles of H₂ formed in situ can elevate the tumor's internal temperature and burst vessels to further destroy the tumor under ultrasound irradiation. Remarkably, vulnerable homeostasis of TME is disturbed as H₂ also participates in the physiological activity of tumor cells, leading to tumor dysfunction. Last but not least, the body's inflammatory response to cancer is reduced after the treatment, which is beneficial for the body's immune system during post-treatment recovery. Based on all of these merits, the H₂ -EC/SD co-therapy provides a potentially safe and viable therapeutic strategy for future clinical applications.

Emerging plasmonic nanoparticles and their assemblies for cancer radiotherapy

Plasmonic nanoparticles and their assemblies have been widely used in biosensing, optical imaging, and biomedicine over the past few decades. Especially in the field of radiotherapy, the physicochemical properties of high-Z plasmonic nanomaterials endow them with the ability to sensitize radiotherapy. Compared with single particles, the assembled structure with tunable properties leads to versatile applications in drug delivery and cancer treatment. In this review, we focus on plasmonic nanoparticles and their assemblies for cancer radiotherapy. First, the sensitization mechanism of plasmonic radiosensitizers is briefly introduced. Subsequently, the recent progress in cancer radiotherapy is systematically discussed according to the structure and shape classification. Finally, the current challenges and future perspectives in this field are also discussed in detail.

Injectable spontaneous hydrogen-releasing hydrogel for long-lasting alleviation of osteoarthritis

Excessive production of reactive oxygen species (ROS) amplifies pro-inflammatory pathways and exacerbates immune responses, and is a key factor in the progression of osteoarthritis (OA). Therapeutic hydrogen gas (H₂) with antioxidative and anti-inflammatory effects, has a potential for OA alleviation, but the targeted delivery and sustained release of H₂ are still challenging. Herein, we develop an injectable calcium boride nanosheets (CBN) loaded hydrogel platform (CBN@GelDA hydrogel) as a high-payload and sustainable H₂ precursor for OA treatment. The CBN@GelDA hydrogel could maintain constant physiological pH conditions which further promotes more H₂ release than the CBN alone and lasts more than one week. The biocompatibility of this hydrogel with macrophages and chondrocytes is effectively enhanced. The experiments show that the CBN@GelDA hydrogel holds the ROS scavenging ability, reducing the expression of related inflammatory cytokines, lessening M1 macrophages but stimulating M2 phenotype, and thereby decreasing chondrocyte apoptosis, which facilitates to breaking of the vicious circle of OA progression. Furthermore, a single-time injection of the CBN@GelDA hydrogel markedly reduces joint destruction in OA rats. From what has been discussed above, this injectable spontaneous H₂-releasing hydrogel is promising for OA treatment. STATEMENT OF SIGNIFICANCE: Oxidative stress and inflammation play the key role in the occurrence and development of osteoarthritis (OA). The system of a hydrogel loaded with H₂ precursor calcium boride nanosheet (CBN), which is the first to use as an H₂ precursor, integrates superior injectable and biocompatible of hydrogel and the selection of antioxidant properties of H₂. This system can improve H₂ release behavior and achieve a single injection into the articular cavity to alleviate the progression of OA in rats. This study of the combination of a convenient long-acting injectable hydrogel and a safe therapeutic gas is of great value for improving the quality of life of clinical patients.

Rational Design of Platinum-Bismuth Sulfide Schottky Heterostructure for Sonocatalysis-Mediated Hydrogen Therapy

Conventional sonodynamic therapy is unavoidably limited by the tumor microenvironment, although many sonosensitizers have been developed to improve them to a certain extent. Given this, a concept of sonocatalytic hydrogen evolution is proposed, which is defined as an oxygen-independent therapeutics. To demonstrate the feasibility of the concept, the narrow-bandgap semiconductor bismuth sulfide (Bi₂ S₃ ) is selected as the sonocatalyst and platinum (Pt) nanoparticles are grown in situ to optimize their catalytic performance. In this nanocatalytic system, the Pt nanoparticles help to capture sonoexcited electrons, whereas intratumoral overexpressed glutathione (GSH), as a natural hole sacrificial agent, can consume sonoexcited holes, which greatly improves the charge-separation efficiency and promotes controllable and sustainable H₂  generation. Even under hypoxic conditions, the Pt-Bi₂ S₃  nanoparticles can also produce sufficient H₂  under ultrasound irradiation. Mechanistically, mitochondrial dysfunction caused by H₂  and intratumoral redox homeostasis destruction by GSH depletion synergistically damage DNA to induce tumor cells apoptosis. At the same time, the Pt nanoparticles and holes can also trigger the decomposition of hydrogen peroxide into O₂  to relieve tumor hypoxia, thus being synergistic with GSH depletion to reverse tumor immunosuppressive microenvironment. The proposed sonocatalysis-mediated therapy will provide a new direction to realize facile and efficient cancer therapy.