Prussian blue nanoparticles: Synthesis, surface modification, and application in cancer treatment

Coamplified Nanozyme Cocktails for Cascade Reaction-Driven Antioxidant Treatments

Antioxidant nanozymes are powerful tools to combat oxidative stress, which can be further improved by applying nanozyme mixtures of multiple enzymatic function. Here, cocktails of Prussian blue (PB) nanocubes and copper(II) exchanged ZSM-5 zeolites (CuZ) with enhanced reactive oxygen species (ROS) scavenging activity were developed. Surface functionalization of the particles was performed using polymers to obtain stable colloids, i.e., resistant to aggregation, under a wide range of experimental conditions. The nanozyme cocktails possessed advanced antioxidant properties with multiple enzyme-like functions, catalyzing the decomposition of ROS in cascade reactions. The activity of the mixture far exceeded that of the individual particles, particularly in the peroxidase assay, where an improvement of more than an order of magnitude was observed, pointing to coamplification of the enzymatic activity. In addition, it was revealed that the copper(II) site in the CuZ plays an important role in the decomposition of both superoxide radicals and hydrogen peroxide, as it directly catalyzes the former reaction and acts as cocatalyst in the latter process by boosting the peroxidase activity of the PB nanozyme. The results give important insights into the design of synergistic particle mixtures for the broad-spectrum scavenging of ROS to develop efficient tools for antioxidant treatments in both medical therapies and industrial manufacturing processes.

Prussian blue nanotechnology in the treatment of spinal cord injury: application and challenges

Spinal cord injury (SCI) is a serious neurological condition that currently lacks effective treatments, placing a heavy burden on both patients and society. Prussian blue nanoparticles exhibit great potential for treating spinal cord injuries due to their excellent physicochemical properties and biocompatibility. These nanoparticles have strong anti-inflammatory and antioxidant capabilities, effectively scavenge free radicals, and reduce oxidative stress damage to cells. Prussian blue nanotechnology shows broad application potential in drug delivery, bioimaging, cancer therapy, anti-inflammatory and oxidative stress treatment, and biosensors. This article reviewed the potential applications of Prussian blue nanotechnology in treating spinal cord injuries, explored the challenges and solutions associated with its application, and discussed the future prospects of this technology in SCI treatment.

Red blood cells based nanotheranostics: A smart biomimetic approach for fighting against cancer

The technique of engineering drug delivery vehicles continues to develop, which bring enhancements in working more efficiently and minimizing side effects to make it more effective and safer. The intense capability of therapeutic agents to remain undamaged in a harsh extracellular environment is helpful to the success of drug development efforts. With this in mind, alterations of biopharmaceuticals with enhanced stability and decreased immunogenicity have been an increasingly active focus of such efforts. Red blood cells (RBCs), also known as erythrocytes have undergone extensive scrutiny as potential vehicles for drug delivery due to their remarkable attributes over the years of research. These include intrinsic biocompatibility, minimal immunogenicity, flexibility, and prolonged systemic circulation. Throughout the course of investigation, a diverse array of drug delivery platforms based on RBCs has emerged. These encompass genetically engineered RBCs, non-genetically modified RBCs, and RBC membrane-coated nanoparticles, each devised to cater to a range of biomedical objectives. Given their prevalence in the circulatory system, RBCs have gained significant attention for their potential to serve as biomimetic coatings for artificial nanocarriers. By virtue of their surface emulation capabilities and customizable core materials, nanocarriers mimicking these RBCs, hold considerable promise across a spectrum of applications, spanning drug delivery, imaging, phototherapy, immunomodulation, sensing, and detection. These multifaceted functionalities underscore the considerable therapeutic and diagnostic potential across various diseases. Our proposed review provides the synthesis of recent strides in the theranostic utilization of erythrocytes in the context of cancer. It also delves into the principal challenges and prospects intrinsic to this realm of research. The focal point of this review pertains to accentuating the significance of erythrocyte-based theranostic systems in combating cancer. Furthermore, it precisely records the latest and the most specific methodologies for tailoring the attributes of these biomimetic nanoscale formulations, attenuating various discoveries for the treatment and management of cancer.

Nanomedicines targeting activated immune cells and effector cells for rheumatoid arthritis treatment

Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease characterized by synovial inflammation and inflammatory cellular infiltration. Functional cells in the RA microenvironment (RAM) are composed of activated immune cells and effector cells. Activated immune cells, including macrophages, neutrophils, and T cells, can induce RA. Effector cells, including synoviocytes, osteoclasts, and chondrocytes, receiving inflammatory stimuli, exacerbate RA. These functional cells, often associated with the upregulation of surface-specific receptor proteins and significant homing effects, can secrete pro-inflammatory factors and interfere with each other, thereby jointly promoting the progression of RA. Recently, some nanomedicines have alleviated RA by targeting and modulating functional cells with ligand modifications, while other nanoparticles whose surfaces are camouflaged by membranes or extracellular vesicles (EVs) of these functional cells target and attack the lesion site for RA treatment. When ligand-modified nanomaterials target specific functional cells to treat RA, the functional cells are subjected to attack, much like the intended targets. When functional cell membranes or EVs are modified onto nanomaterials to deliver drugs for RA treatment, functional cells become the attackers, similar to arrows. This study summarized how diversified functional cells serve as targets or arrows by engineered nanoparticles to treat RA. Moreover, the key challenges in preparing nanomaterials and their stability, long-term efficacy, safety, and future clinical patient compliance have been discussed here.

Enhanced dispersion of prussian blue via intercalation into layered double hydroxides for efficient solar seawater evaporation

Prussian blue (PB) is favored for its photothermal absorption capability in solar vapor generation applications. However, the photothermal conversion efficiency of current PB-based devices is limited by the material's poor dispersion. Herein, we report a method of incorporating PB in the interlayers of layered double hydroxides (LDHs) to prevent its aggregation. The dispersion is further enhanced and stabilized by the addition of sodium dodecyl sulfate (SDS). The thermal and water stability of PB is improved due to the rigid structure of LDHs and interactions between layers and anions. Elemental analysis confirms that with the increase of molar ratio of Mg/Al and the introduction of SDS, concentrations of PB are decreased accordingly. As a result, the rate of solar vapor generation is increased by 35.9% for powders containing 50 mg of equivalent PB. Of note, converting this material into a three-dimensional structure of high rebound foam further enhances solar water evaporation rate, from 0.79 kg m-2 h-1 to 0.98 kg m-2 h-1, with only 20 mg of equivalent PB, increasing the corresponding photothermal conversion efficiency from 53.8% to 66.3%.

Modulating synovial macrophage pyroptosis and mitophagy interactions to mitigate osteoarthritis progression using functionalized nanoparticles

Synovial macrophages play an important role in the progression of osteoarthritis (OA). In this study, we noted that synovial macrophages can activate pyroptosis in a gasdermin d-dependent manner and produce reactive oxygen species (ROS), aberrantly activating the mammalian target of rapamycin complex 1 (mTORC1) pathway and matrix metalloproteinase-9 (MMP9) expression in synovial tissue samples collected from both patients with OA and collagen-induced osteoarthritis (CIOA) mouse model. To overcome this, we constructed rapamycin- (RAPA, a mTORC1 inhibitor) loaded mesoporous Prussian blue nanoparticles (MPB NPs, for catalyzing ROS) and modified the NPs with MMP9-targeted peptides (favor macrophage targeting) to develop RAPA@MPB-MMP9 NPs. The inherent enzyme-like activity and RAPA released from RAPA@MPB-MMP9 NPs synergistically impeded the pyroptosis of macrophages and the activation of the mTORC1 pathway. In particular, the NPs decreased pyroptosis-mediated ROS generation, thereby inhibiting cGAS-STING signaling pathway activation caused by the release of mitochondrial DNA. Moreover, the NPs promoted macrophage mitophagy to restore mitochondrial stability, alleviate pyroptosis-related inflammatory responses, and decrease senescent synoviocytes. After the as-prepared NPs were intra-articularly injected into the CIOA mouse model, they efficiently attenuated synovial macrophage pyroptosis and cartilage degradation. In conclusion, our study findings provide a novel therapeutic strategy for OA that modulates the pyroptosis and mitophagy of synovial macrophage by utilizing functionalized NPs. STATEMENT OF SIGNIFICANCE: Osteoarthritis (OA) presents a significant global challenge owing to its complex pathogenesis and finite treatment options. Synovial macrophages have emerged as key players in the progression of OA, managing inflammation and tissue destruction. In this study, we discovered a novel therapeutic strategy in which the pyroptosis and mitophagy of synovial macrophages are targeted to mitigate OA pathology. For this, we designed and prepared rapamycin-loaded mesoporous Prussian blue nanoparticles (RAPA@MPB-MMP9 NPs) to specifically target synovial macrophages and modulate their inflammatory responses. These NPs could efficiently suppress macrophage pyroptosis, diminish reactive oxygen species production, and promote mitophagy, thereby alleviating inflammation and protecting cartilage integrity. Our study findings not only clarify the intricate mechanisms underlying OA pathogenesis but also present a promising therapeutic approach for effectively managing OA by targeting dysregulation in synovial macrophages.

Exosome-Coated Prussian Blue Nanoparticles for Specific Targeting and Treatment of Glioblastoma

Glioblastoma is one of the most aggressive and invasive types of brain cancer with a 5-year survival rate of 6.8%. With limited options, patients often have poor quality of life and are moved to palliative care after diagnosis. As a result, there is an extreme need for a novel theranostic method that allows for early diagnosis and noninvasive treatment as current peptide-based delivery standards may have off-target effects. Prussian Blue nanoparticles (PBNPs) have recently been investigated as photoacoustic imaging (PAI) and photothermal ablation agents. However, due to their inability to cross the blood-brain barrier (BBB), their use in glioblastoma treatment is limited. By utilizing a hybrid, biomimetic nanoparticle composed of a PBNP interior and a U-87 cancer cell-derived exosome coating (Exo:PB), we show tumor-specific targeting within the brain and selective thermal therapy potential due to the strong photoconversion abilities. Particle characterization was carried out and showed a complete coating around the PBNPs that contains exosome markers. In vitro cellular uptake patterns are similar to native U-87 exosomes and when exposed to an 808 nm laser, show localized cell death within the specified region. After intravenous injection of Exo:PB into subcutaneously implanted glioblastoma mice, they have shown effective targeting and eradication of tumor volume compared to PEG-coated PBNPs (PEG:PB). Through systemic administration of Exo:PB particles into orthotopic glioblastoma-bearing mice, the PBNP signal was detected in the brain tumor region through PAI. It was seen that Exo:PB had preferential tumor accumulation with less off-targeting compared to the RGD:PB control. Ex vivo analysis validated specific targeting with a direct overlay of Exo:PB with the tumor by both H&E staining and Ki67 labeling. Overall, we have developed a novel biomimetic material that can naturally cross the BBB and act as a theranostic agent for systemic targeting of glioblastoma tissue and photothermal therapeutic effect.

Red cell membrane-coating Prussian blue for combined photothermal and NO gas therapy for nasopharyngeal carcinoma

Nitric oxide (NO) gas molecules have demonstrated remarkable anti-tumor effects and minimal susceptibility to drug resistance, establishing as a promising modality for effective tumor treatment. However, how to realize its stable and efficient delivery in vivo is still a challenge. In this study, we have developed a heat-responsive biomimetic nano erythrocyte (M/B@R) by loading a NO donor (BNN6) onto mesoporous Prussian blue (M-PB) and subsequently enveloping them with red blood cell membranes. The preserved integrity of the red blood cell membrane (RBCm) structure could ensure its excellent biosafety, prolong its circulation time within the bloodstream and then enhance the accumulation of BNN6 at tumor sites. When M/B@R is stimulated by near-infrared light (NIR-II, 808 nm) irradiation, the nanoparticle could generate significant heat for photothermal therapy (PTT) by the characteristic NIR absorption of M-PB and then NO could also be efficiently released. The generated NO further facilitates the formation of ONOO-, a highly toxic species to tumors, while also alleviating tumor hypoxia. Remarkably, M/B@R, with NIR as the excitation source, induces combined lethality through hyperthermia, DNA damage, and tumor hypoxia relief. This novel combination strategy provides a new avenue for PTT/NO-induced cancer therapy.

Smart Nanozymes for Cancer Therapy: The Next Frontier in Oncology

Nanomaterials that mimic the catalytic activity of natural enzymes in the complex biological environment of the human body are called nanozymes. Recently, nanozyme systems have been reported with diagnostic, imaging, and/or therapeutic capabilities. Smart nanozymes strategically exploit the tumor microenvironment (TME) by the in situ generation of reactive species or by the modulation of the TME itself to result in effective cancer therapy. This topical review focuses on such smart nanozymes for cancer diagnosis, and therapy modalities with enhanced therapeutic effects. The dominant factors that guide the rational design and synthesis of nanozymes for cancer therapy include an understanding of the dynamic TME, structure-activity relationships, surface chemistry for imparting selectivity, and site-specific therapy, and stimulus-responsive modulation of nanozyme activity. This article presents a comprehensive analysis of the subject including the diverse catalytic mechanisms of different types of nanozyme systems, an overview of the TME, cancer diagnosis, and synergistic cancer therapies. The strategic application of nanozymes in cancer treatment can well be a game changer in future oncology. Moreover, recent developments may pave the way for the deployment of nanozyme therapy into other complex healthcare challenges, such as genetic diseases, immune disorders, and ageing.

Prussian blue nanozymes: progress, challenges, and opportunities

Prussian Blue Nanozymes (PBNZs) have emerged as highly efficient agents for reactive oxygen species (ROS) elimination, owing to their multiple enzyme-like properties encompassing catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) activities. As a functional nanomaterial mimicking enzyme, PBNZs not only surmount the limitations of natural enzymes, such as instability and high manufacturing costs, but also exhibit superior stability, tunable activity, low storage expenses, and remarkable reusability. Consequently, PBNZs have gained significant attention in diverse biomedical applications, including disease diagnosis and therapy. Over the past decade, propelled by advancements in catalysis science, biotechnology, computational science, and nanotechnology, PBNZs have witnessed remarkable progress in the exploration of their enzymatic activities, elucidation of catalytic mechanisms, and wide-ranging applications. This comprehensive review aims to provide a systematic overview of the discovery and catalytic mechanisms of PBNZ, along with the strategies employed to modulate their multiple enzyme-like activities. Furthermore, we extensively survey the recent advancements in utilizing PBNZs for scavenging ROS in various biomedical applications. Lastly, we analyze the existing challenges of translating PBNZs into therapeutic agents for clinical use and outline future research directions in this field. By presenting a comprehensive synopsis of the current state of knowledge, this review seeks to contribute to a deeper understanding of the immense potential of PBNZs as an innovative therapeutic agent in biomedicine.

Fe-involved nanostructures act as photothermal transduction agents in cancer photothermal therapy

Cancer, a disease notorious for its difficult therapy regimen, has long puzzled researchers. Despite attempts to cure cancer using surgery, chemotherapy, radiotherapy, and immunotherapy, their effectiveness is limited. Recently, photothermal therapy (PTT), a rising strategy, has gained attention. PTT can increase the surrounding temperature of cancer tissues and cause damage to them. Fe is widely used in PTT nanostructures due to its strong chelating ability, good biocompatibility, and the potential to induce ferroptosis. In recent years, many nanostructures incorporating Fe3+ have been developed. In this article, we summarize PTT nanostructures containing Fe and introduce their synthesis and therapy strategy. However, PTT nanostructures containing Fe are still in their infancy, and more effort must be devoted to improving their effectiveness so that they can eventually be used in clinics.

Prussian Blue nanoparticles: An FDA-approved substance that may quickly degrade at physiological pH

Prussian blue (PB) is a coordination polymer based on the Fe^2+…CN^…Fe³⁺ sequence. It is an FDA-approved drug, intended for oral use at the acidic pH of the stomach and of most of the intestine track. However, based on FDA approval, a huge number of papers proposed the use of PB nanoparticles (PBnp) under "physiological conditions", meaning pH buffered at 7.4 and high saline concentration. While most of these papers report that PBnp are stable at this pH, a small number of papers describes instead PBnp degradation at the same or similar pH values, i.e. in the 7-8 range. Here we give a definitively clear picture: PBnp are intrinsically unstable at pH ≥ 7, degrading with the fast disappearance of their 700 nm absorption band, due to the formation of OH^- complexes from the labile Fe³⁺ centers. However, we show also that the presence of a polymeric coating (PVP) can protect PBnp at pH 7.4 for over 24 h. Moreover, we demonstrate that when "physiological conditions" include serum, a protein corona is rapidly formed on PBnp, efficiently avoiding degradation. We also show that the viability of PBnp-treated EA.hy926, NCI-H1299, and A549 cells is not affected in a wide range of conditions that either prevent or promote PBnp degradation.

Near-infrared light-controlled kartogenin delivery of multifunctional Prussian blue nanocomposites for cartilage defect repair

Articular cartilage injury repair remains a challenge for clinicians and researchers. Mesenchymal stem cells (MSCs) have multiple differentiation potentials and can be induced to differentiate into the chondrogenic lineage for cartilage defect repair; however, the insufficient capacity of chondrogenic differentiation and excess reactive oxygen species (ROS)-mediated oxidative stress, which always lead to differentiation into hypertrophic chondrocytes, still need to be resolved. Accordingly, kartogenin (KGN), which can promote chondrogenic differentiation of MSCs, has shown promise in promoting infected cartilage repair. However, realizing controllable release to prolong its action time and avoid hypertrophic differentiation is critical. We herein developed a mesoporous Prussian blue nanoparticle (mPB)-based near-infrared (NIR) light-responsive controlled nanosystem. KGN was encapsulated in temperature-stimulated responsive phase change materials (PCMs), which were used as excellent gating materials (KGN-PCM@mPBs). In addition, the mPBs could efficiently scavenge ROS by their enzyme-like antioxidative activities. Our study demonstrates that the nanocomposites could efficiently promote chondrogenic differentiation and successfully inhibit the hypertrophic differentiation of MSCs. By intra-articular injection of KGN-PCM@mPBs and NIR-triggered precisely controlled release, satisfactory cartilage repair effects can be achieved in a rat chondral defect model. Thus, this constructed NIR-mediated KGN-PCM@mPB nanoplatform may represent an effective cartilage repair strategy with satisfactory biosafety in clinical applications.

Recent advances in Prussian blue-based photothermal therapy in cancer treatment

Malignant tumours are a serious threat to human health. Traditional chemotherapy has achieved breakthrough improvements but also has significant detrimental effects, such as the development of drug resistance, immunosuppression, and even systemic toxicity. Photothermal therapy (PTT) is an emerging cancer therapy. Under light irradiation, the phototherapeutic agent converts optical energy into thermal energy and induces the hyperthermic death of target cells. To date, numerous photothermal agents have been developed. Prussian blue (PB) nanoparticles are among the most promising photothermal agents due to their excellent physicochemical properties, including photoacoustic and magnetic resonance imaging properties, photothermal conversion performance, and enzyme-like activity. By the construction of suitably designed PB-based nanotherapeutics, enhanced photothermal performance, targeting ability, multimodal therapy, and imaging-guided cancer therapy can be effectively and feasibly achieved. In this review, the recent advances in PB-based photothermal combinatorial therapy and imaging-guided cancer therapy are comprehensively summarized. Finally, the potential obstacles of future research and clinical translation are discussed.

Engineering ROS-scavenging Prussian blue nanozymes for efficient atherosclerosis nanotherapy

Atherosclerosis (AS), characterized by a chronic inflammatory disease, is a top cause of morbidity and disability worldwide. During the pathogenesis of AS, the leading process of inflammation highly involves a secondary event of oxidative stress, but limited antioxidants are currently available clinically due to their nonspecific effects, poor biosafety, and rapid in vivo elimination and urinary excretion as well as short retention time within plaque lesions. In this work, Prussian blue nanozymes with a strong reactive oxygen species (ROS)-scavenging ability were rationally engineered for efficient AS nanotherapy. Specifically, the obtained nanozymes with high photothermal performance could behave as potent photoacoustic imaging agents for plaque detection. In addition, these nanozymes featuring multienzyme activities could reduce the cellular ROS level, exert cytoprotective effects against ROS-mediated macrophages apoptosis, and inhibit foam cell formation, significantly boycotting AS development. The underlying mechanism was further verified by transcriptome sequencing at the cellular level and a series of immunohistochemical staining of aortic sinus sections in apoE^-/- mice. Finally, the high biocompatibility and biosafety of the engineered Prussian blue nanozymes further guarantee their clinical translation potential for AS management.

Prussian Blue Sensor for Bacteria Detection in Personal Protection Clothing

Biological hazards can be defined as substances that endanger the life of any living organism, most notably humans, and are often referred to as biohazards. Along with the use of personal protective equipment (PPE), early detection of contact is essential for the correct management and resolution of a biological threat, as well as lower mortality rates of those exposed. Herein, Prussian blue (PB) was evaluated as a functional compound applied on polyester knits to act as an on-site sensor for bacteria detection. In order to study the best compound concentration for the intended application, polymeric solutions of 0.5, 1 and 2 g/L were developed. The three conditions tested displayed high abrasion resistance (>2000 cycles). The bacterial sensing capacity of the coated knits was assessed in liquid and solid medium, with the functionalised substrates exhibiting the capability of detecting both Gram-positive and Gram-negative bacteria and changing colours from blue to white. Evaluation of water repellence and chemical penetration resistance and repellence was also performed in polyester functionalised with PB 0.5 and 1 g/L. Both knits showed a hydrophobic behaviour and a capacity to resist to penetration of chemicals and level 3 repellence effect for both acid and base chemicals.

Smart Biomimetic Nanozymes for Precise Molecular Imaging: Application and Challenges

New nanotechnologies for imaging molecules are widely being applied to visualize the expression of specific molecules (e.g., ions, biomarkers) for disease diagnosis. Among various nanoplatforms, nanozymes, which exhibit enzyme-like catalytic activities in vivo, have gained tremendously increasing attention in molecular imaging due to their unique properties such as diverse enzyme-mimicking activities, excellent biocompatibility, ease of surface tenability, and low cost. In addition, by integrating different nanoparticles with superparamagnetic, photoacoustic, fluorescence, and photothermal properties, the nanoenzymes are able to increase the imaging sensitivity and accuracy for better understanding the complexity and the biological process of disease. Moreover, these functions encourage the utilization of nanozymes as therapeutic agents to assist in treatment. In this review, we focus on the applications of nanozymes in molecular imaging and discuss the use of peroxidase (POD), oxidase (OXD), catalase (CAT), and superoxide dismutase (SOD) with different imaging modalities. Further, the applications of nanozymes for cancer treatment, bacterial infection, and inflammation image-guided therapy are discussed. Overall, this review aims to provide a complete reference for research in the interdisciplinary fields of nanotechnology and molecular imaging to promote the advancement and clinical translation of novel biomimetic nanozymes.

Novel targeted pH-responsive drug delivery systems based on PEGMA-modified bimetallic Prussian blue analogs for breast cancer chemotherapy

The development of novel nanoparticle-based drug delivery systems (nano-DDSs) with high loading capacity, low toxicity, precise targeting, and excellent biocompatibility remains urgent and important for the treatment of breast cancer (BC). Herein, novel BC-targeted nano-DDSs based on bimetallic Prussian blue analogs (PBA-DDSs) for intracellular doxorubicin (DOX) delivery and pH-responsive release were developed. Two kinds of bimetallic PBA, namely CuFe (copper-iron) PBA and CoFe (cobalt-iron) PBA, were synthesized by a coprecipitation method, followed by modification with polyethyleneglycol methacrylate (PEGMA) via surface-initiated atom transfer radical polymerization and immobilization with the AS1411 aptamer to obtain two kinds of novel BC-targeted nano-DDS. CuFePBA@PEGMA@AS1411 and CoFePBA@PEGMA@AS1411 showed high drug loading efficiency of 80% and 84%, respectively, for DOX, while 56.0% and 75.9% DOX release could be achieved under acidic pH conditions. In vitro cell viability and in vivo experiments proved the good biocompatibility of both PBA-DDSs. Cellular uptake and in vivo distribution suggested that both PBA-DDSs had efficient nucleolin-targeting capability, indicating the targeted delivery of DOX in tumor tissues. In vivo evaluation of anti-BC efficacy further confirmed that the obtained PBA-DDSs exhibited excellent therapeutic efficacy with limited side-effects. Therefore, the proposed novel PBA-DDSs can be used as secure and effective drug nano-DDSs for BC chemotherapy.

Dual mode antibacterial surfaces based on Prussian blue and silver nanoparticles

Prussian Blue (PB) is an inexpensive, biocompatible, photothermally active material. In this paper, self-assembled monolayers of PB nanoparticles were grafted on a glass surface, protected with a thin layer of silica and decorated with spherical silver nanoparticles. This combination of a photothermally active nanomaterial, PB, and an intrinsically antibacterial one, silver, leads to a versatile coating that can be used for medical devices and implants. The intrinsic antibacterial action of nanosilver, always active over time, can be enhanced on demand by switching on the photothermal effect of PB using near infrared (NIR) radiation, which has a good penetration depth through tissues and low side effects. Glass surfaces functionalized by this layer-by-layer approach have been characterized for their morphology and composition, and their intrinsic and photothermal antibacterial effect was studied against Gram+ and Gram- planktonic bacteria.

Manganese-based Prussian blue nanoparticles inhibit tumor proliferation and migration via the MAPK pathway in pancreatic cancer

Pancreatic cancer (PC) is one of the deadliest gastrointestinal malignancies. Advances in molecular biology and surgery have significantly improved survival rates for other tumors in recent decades, but clinical outcomes for PC remained relatively unchanged. Chemodynamic therapy (CDT) and Photothermal therapy (PTT) represent an efficient and relatively safe cancer treatment modality. Here, we synthesized Mn-doped Prussian blue nanoparticles (MnPB NPs) through a simple and mild method, which have a high loading capacity for drugs and excellent CDT/PTT effect. Cell line experiments in vitro and animal experiments in vivo proved the safety of MnPB NPs. We stimulated the PC cells with MnPB NPs and performed transwell migration assays. The migration of PC cells was reduced company with the decrease of two classical proteins: matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9). Moreover, MnPB NPs induced ferroptosis, which mediated the MAPK pathway and achieved tumor elimination in nude mice. This effective and safe strategy controlled by irradiation represents a promising strategy for pancreatic cancer.

Perspectives of metal-organic framework nanosystem to overcome tumor drug resistance

Cancer is one of the most harmful diseases in the world, which causes huge numbers of deaths every year. Many drugs have been developed to treat tumors. However, drug resistance usually develops after a period of time, which greatly weakens the therapeutic effect. Tumor drug resistance is characterized by blocking the action of anticancer drugs, resisting apoptosis and DNA repair, and evading immune recognition. To tackle tumor drug resistance, many engineered drug delivery systems (DDS) have been developed. Metal-organic frameworks (MOFs) are one kind of emerging and promising nanocarriers for DDS with high surface area and abundant active sites that make the functionalization simpler and more efficient. These features enable MOFs to achieve advantages easily towards other materials. In this review, we highlight the main mechanisms of tumor drug resistance and the characteristics of MOFs. The applications and opportunities of MOF-based DDS to overcome tumor drug resistance are also discussed, shedding light on the future development of MOFs to address tumor drug resistance.

A magnetic antibody-conjugated nano-system for selective delivery of Ca(OH)2 and taxotere in ovarian cancer cells

An efficient strategy for cancer therapy is presented, in which a tumor mass is initially pretreated with calcium hydroxide, then treated with Taxotere (TXT). In this regard, an advanced delivery system based on iron oxide nanoparticles has been designed. The surface of nanoparticles was functionalized with sortilin (SORT-1, a human IgG1 monoclonal antibody) that specifically encodes caov-4 ovarian cancerous cells. Plasmonic heating of the incorporated gold nanoparticles in polyvinyl alcohol (PVA) has been exploited to control the release process of TXT. The in vitro, ex vivo and in vivo experiments have exhibited high efficacy of a seven-day pretreatment by Ca(OH)₂ plus 14 days treatment program by Ca(OH)₂@Fe₃O₄/PVA/Au-SORT nano-therapeutics, where more penetration ratio resulted in tumor growth inhibition by ca. 78.3%. As a result, due to showing high values of the anti-tumor properties and biosafety, the presented pretreatment strategy is suggested for more effective treatment on the aged tumors.

A magnetic drug delivery system containing polyvinyl alcohol, gold nanoparticles, and sortilin antibody followed by the plasmonic photothermal heating strategy for the controlled drug release is proposed, with use in ovarian cancer demonstrated.

Synthesis and preclinical application of a Prussian blue-based dual fluorescent and magnetic contrast agent (CA)

The aim of this study was to develop and characterize a Prussian Blue based biocompatible and chemically stable T1 magnetic resonance imaging (MRI) contrast agent with near infrared (NIR) optical contrast for preclinical application. The physical properties of the Prussian blue nanoparticles (PBNPs) (iron (II); iron (III);octadecacyanide) were characterized with dynamic light scattering (DLS), zeta potential measurement, atomic force microscopy (AFM), and transmission electron microscopy (TEM). In vitro contrast enhancement properties of PBNPs were determined by MRI. In vivo T1-weighted contrast of the prepared PBNPs was investigated by MRI and optical imaging modality after intravenous administration into NMRI-Foxn1 nu/nu mice. The biodistribution studies showed the presence of PBNPs predominantly in the cardiovascular system. Briefly, in this paper we show a novel approach for the synthesis of PBNPs with enhanced iron content for T1 MRI contrast. This newly synthetized PBNP platform could lead to a new diagnostic agent, replacing the currently used Gadolinium based substances.

Research Progress of Photothermal Nanomaterials in Multimodal Tumor Therapy

The aggressive growth of cancer cells brings extreme challenges to cancer therapy while triggering the exploration of the application of multimodal therapy methods. Multimodal tumor therapy based on photothermal nanomaterials is a new technology to realize tumor cell thermal ablation through near-infrared light irradiation with a specific wavelength, which has the advantages of high efficiency, less adverse reactions, and effective inhibition of tumor metastasis compared with traditional treatment methods such as surgical resection, chemotherapy, and radiotherapy. Photothermal nanomaterials have gained increasing interest due to their potential applications, remarkable properties, and advantages for tumor therapy. In this review, recent advances and the common applications of photothermal nanomaterials in multimodal tumor therapy are summarized, with a focus on the different types of photothermal nanomaterials and their application in multimodal tumor therapy. Moreover, the challenges and future applications have also been speculated.

Prussian Blue Nanoparticle-Mediated Scalable Thermal Stimulation for In Vitro Neuronal Differentiation

Heating has recently been applied as an alternative to electrical stimulation to modulate excitability and to induce neuritogenesis and the expression of neuronal markers; however, a long-term functional differentiation has not been described so far. Here, we present the results obtained by a new approach for scalable thermal stimulation on the behavior of a model of dorsal root ganglion neurons, the F-11 cell line. Initially, we performed experiments of bulk stimulation in an incubator for different time intervals and temperatures, and significant differences in neurite elongation and in electrophysiological properties were observed in cultures exposed at 41.5 °C for 30 min. Thus, we exposed the cultures to the same temperature increase using a near-infrared laser to irradiate a disc of Prussian blue nanoparticles and poly-vinyl alcohol that we had adhered to the outer surface of the petri dish. In irradiated cells, neurites were significantly longer, and the electrophysiological properties (action potential firing frequency and spontaneous activity) were significantly increased compared to the control. These results show for the first time that a targeted thermal stimulation could induce morphological and functional neuronal differentiation and support the future application of this method as a strategy to modify neuronal behavior in vivo.

Development of an optical immunoassay based on peroxidase-mimicking Prussian blue nanoparticles and a label-free electrochemical immunosensor for accurate and sensitive quantification of milk species adulteration

In contrast to reported enzyme-based immunoassays, an enzyme-free immunoassay (optical and electrochemical) is presented here for the first time that can be used as point-of-need detection bioplatforms of bovine IgG as goat milk adulterant. In the first format, Prussian blue nanoparticles (PBNPs) were used as antibody catalytic labels in a competitive colorimetric microplate immunoassay. Absorbance measurement was performed photometrically at 450 nm. After in-depth optimization, excellent sensitivity was achieved (0.01% cow/goat volume ratio), which is 100 times lower than the limit allowed by the European legislation (EL) (1% v/v), thanks to the high catalytic activity of PBNPs compared with natural peroxidase. Moreover, the antibody-PBNPs bioconjugates showed excellent stability over 4 weeks (> 94% of the initial response) confirming the successful anchoring of the antibodies to the surface of the PBNPs. On the other hand, a label-free voltammetric immunoassay for the detection of bovine IgG was developed. The sensing principle was based on the hindrance of charge transfer between ferri-ferrocyanide redox couple and the screen-printed gold electrodes modified with bovine IgG antibody. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to characterize the step-by-step modification of the electrode surface. Under optimal conditions, this single-step electrochemical analysis achieved a high sensitivity of 0.1% (cow/goat) when monitoring the ferrocyanide oxidation at + 0.092 V (vs. Ag/AgCl) using differential pulse voltammetry (DPV). The selectivity of the developed immunoassays was evaluated for different species of milk of similar composition, and both immunoassays exhibited a selective response only to bovine IgG. Unlike conventional immunoassays, the developed enzyme-free immunoassays have many attractive features for the detection of milk adulteration, whether they are used in quality control laboratories for routine milk analysis (optical immunoassay) or at on-site checkpoints (electrochemical immunoassay) using wireless electrochemical detectors. The sensors provide high sensitivity (≤ 0.1%), excellent precision (RSD < 6%), low cost (no enzyme is required) and ease of operation, including handling of milk samples.

Gold-based hybrid nanostructures: more than just a pretty face for combinational cancer therapy

The early diagnosis together with an efficient therapy of cancer is essential to treat cancer patients and to enhance their quality of life. The use of nanostructures, as a newer technology, has demonstrated proven benefits as efficient cancer theranostic agents in numerous recent studies. Having a tunable surface plasmon resonance, gold nanostructures have been the subject of many recent studies as excellent imaging and photothermal therapy agents. However, the potential cytotoxicity and weak stability of gold nanostructures necessitate further modifications using biocompatible materials for biological applications. Based on the composition of the final structure, these gold-based hybrid nanostructures (GHNs) could be divided into five major groups; each of which has specific pros and cons. Understanding the strengths and weaknesses of each group helps scientists to optimize GHN designs with multiple functions by synergizing the benefits of different groups. This review aims to summarize the advancements in GHN design and provide a perspective view of future requirements for successful GHN-based targeted combinational cancer theranostic platforms.

Single-walled carbon nanotubes as a reducing agent for the synthesis of a Prussian blue-based composite: a quartz crystal microbalance study

We investigated the synthesis mechanism of Prussian blue (PB) crystals supported on single-walled carbon nanotubes (SWCNTs), by performing in situ quartz crystal microbalance (QCM) measurements to probe the change in the electrode mass during the reaction, and using photoirradiation at designated stages of the process. We found that in contrast to existing hypotheses, light irradiation played no role in the synthesis process of Prussian blue on SWCNTs. On the other hand, the number of electrons transferred per one mole of the obtained product, and the number of electrons transferrable from SWCNTs, calculated from the density of states (DOS) of the SWCNTs in the sample, both favor the hypothesis of the reaction being triggered by direct electron transfer from SWCNTs to Fe³⁺, which occurs because of the energy difference between the Fermi level of SWCNTs and redox potential of Fe³⁺ ions.

Post-synthetic modification of Prussian blue type nanoparticles: tailoring the chemical and physical properties

This review focuses on recent advances in the post-synthetic modification of nano-sized Prussian blue and its analogues and compares them with the current strategies used in metal–organic frameworks to give future outlooks in this field.

Self-Assembly Cascade Reaction Platform for CD44 Positive Lung Cancer Therapy

Lung cancer, as one of the most fatal cancers around the world, is responsible for the death of millions every year. Among various types of lung cancers, the ones overexpressing CD44 is usually associated higher cell proliferation with poorer prognosis. Therefore, finding a way to effectively treat CD44 positive lung cancer is urgently needed. Here in this study, negatively charged ultrasmall prussian blue nanoparticles (UPBNPs) was firstly synthesized and adsorbed to polyethyleneimine (PEI) together with glucose oxidase (Gox). Afterwards, the PEI was further complexed with hyaluronic acid (HA) to give a cascade reaction platform (HP/UPB-Gox) for CD44 positive lung cancer therapy. The HP/UPB-Gox with HA shell was able to positively target CD44 overexpressed A549 cells. Upon arriving at the tumor tissue, the Gox catalyzed the glucose of tumor to create H₂O₂, which further served as the substrate of UPBNPs, a peroxidase mimic, to finally give highly toxic hydroxyl radical (OH) for cancer therapy. Therefore, the cascade reaction formed between UPBNPs and Gox was expected to realize effective treatment on CD44 overexpressed lung cancer.

Multifunctional Biodegradable Prussian Blue Analogue for Synergetic Photothermal/Photodynamic/Chemodynamic Therapy and Intrinsic Tumor Metastasis Inhibition

To date, various Prussian blue analogues (PBAs) have been prepared for biomedical applications due to their unique structural advantages. However, the safety and effectiveness of tumor treatment still need further exploration. This contribution reports a facile synthesis of PBA with superior tumor synergetic therapeutic effects and a detailed mechanistic evaluation of their intrinsic tumor metastasis inhibition activity. The as-synthesized PBA has a uniform cube structure with a diameter of approximately 220 nm and shows high near-infrared light (NIR) photoreactivity, photothermal conversion efficiency (41.44%), and photodynamic effect. Additionally, PBA could lead to a chemodynamic effect, which is caused by the Fenton reaction and ferroptosis. The combined therapy strategy of PBA exhibits notable tumor ablation properties due to photothermal therapy (PTT)/photodynamic therapy (PDT)/chemodynamic therapy (CDT) effects without obvious toxicity in vivo. The PBA has also shown potential as a contrast agent for magnetic resonance imaging (MRI) and photoacoustic (PA) imaging. More importantly, careful investigations reveal that PBA displays excellent biodegradation and anti-metastasis properties. Further exploration of the PBA implies that its underlying mechanism of intrinsic tumor metastasis inhibition activity can be attributed to the modulation of epithelial-mesenchymal transition (EMT) expression. The considerable potential exhibited by the as-synthesized PBA makes it an ideal candidate as a synergetic therapeutic agent for tumor treatment.

RGD Peptide and PAD4 Inhibitor-Loaded Gold Nanorods for Chemo-Photothermal Combined Therapy to Inhibit Tumor Growth, Prevent Lung Metastasis and Improve Biosafety

Purpose

A targeted drug delivery system that combines protein-arginine deiminase type-4 (PAD4) inhibitors YW3-56 (356) with PTT of NPs is constructed to both decrease the accumulation of gold in metabolic organs and reduce the dose of chemotherapeutic agents.

Patients and Methods

In vitro cytotoxicity test and in vivo S180 tumor-bearing mice model were used to compare antitumor activity of 356-modified gold nanospheres and nanorods. The A549 tumor-bearing mice model was also exploited in antitumor assessment. In addition, ICP-MS, blood cell analyzer and blood biochemistry analyzer are applied for assessing the biosafety of NPs.

Results

Both 356-modified gold nanospheres and nanorods showed antitumor activity. However, 356-loaded gold nanorods are found to have better tumor inhibitory activity than 356-loaded gold nanospheres in the presence of laser and without laser irradiation. Thus, 356-loaded gold nanorods are selected to be applied for chemo-photothermal combined therapy on in vivo. We find that combination therapy could inhibit tumor growth and reduce lung tumor metastasis and inflammatory infiltration compared with individual therapy. It triggers apoptosis in tumor tissue observed by TUNEL assay and TEM pictures.

Conclusion

Thus, an RGD targeting and PAD4 inhibitor-loaded system are established based on chemo-photothermal combined therapy. It could inhibit tumor growth, prevent lung metastasis and improve biosafety.

Onco-Receptors Targeting in Lung Cancer via Application of Surface-Modified and Hybrid Nanoparticles: A Cross-Disciplinary Review

Lung cancer is among the most prevalent and leading causes of death worldwide. The major reason for high mortality is the late diagnosis of the disease, and in most cases, lung cancer is diagnosed at fourth stage in which the cancer has metastasized to almost all vital organs. The other reason for higher mortality is the uptake of the chemotherapeutic agents by the healthy cells, which in turn increases the chances of cytotoxicity to the healthy body cells. The complex pathophysiology of lung cancer provides various pathways to target the cancerous cells. In this regard, upregulated onco-receptors on the cell surface of tumor including epidermal growth factor receptor (EGFR), integrins, transferrin receptor (TFR), folate receptor (FR), cluster of differentiation 44 (CD44) receptor, etc. could be exploited for the inhibition of pathways and tumor-specific drug targeting. Further, cancer borne immunological targets like T-lymphocytes, myeloid-derived suppressor cells (MDSCs), tumor-associated macrophages (TAMs), and dendritic cells could serve as a target site to modulate tumor activity through targeting various surface-expressed receptors or interfering with immune cell-specific pathways. Hence, novel approaches are required for both the diagnosis and treatment of lung cancers. In this context, several researchers have employed various targeted delivery approaches to overcome the problems allied with the conventional diagnosis of and therapy methods used against lung cancer. Nanoparticles are cell nonspecific in biological systems, and may cause unwanted deleterious effects in the body. Therefore, nanodrug delivery systems (NDDSs) need further advancement to overcome the problem of toxicity in the treatment of lung cancer. Moreover, the route of nanomedicines’ delivery to lungs plays a vital role in localizing the drug concentration to target the lung cancer. Surface-modified nanoparticles and hybrid nanoparticles have a wide range of applications in the field of theranostics. This cross-disciplinary review summarizes the current knowledge of the pathways implicated in the different classes of lung cancer with an emphasis on the clinical implications of the increasing number of actionable molecular targets. Furthermore, it focuses specifically on the significance and emerging role of surface functionalized and hybrid nanomaterials as drug delivery systems through citing recent examples targeted at lung cancer treatment.

Fluorescence imaging-guided cancer photothermal therapy using polydopamine and graphene quantum dot-capped Prussian blue nanocubes

In recent years, imaging-guided photothermal tumor ablation has attracted intense research interest as one of the most exciting strategies for cancer treatment. Herein, we prepared polydopamine and graphene quantum dot-capped Prussian blue nanocubes (PB@PDA@GQDs, PBPGs) with high photothermal conversion efficiency and excellent fluorescence performance for imaging-guided cancer treatment. Transmission electron microscopy (TEM), UV-vis absorption spectroscopy (UV-vis), fluorescence spectroscopy, and X-ray photoelectron spectroscopy (XPS) were employed to characterize their morphology and structures. The photothermal conversion efficiency and therapeutic effect were evaluated in vitro and in vivo. Results revealed that this nanoagent had excellent biocompatibility and enhanced the photothermal effect compared to blue nanocubes (PBs) and polydopamine-capped Prussian blue nanocubes (PB@PDA, PBPs). Therefore, our study may open a new path for the production of PB-based nanocomposites as theranostic nanoagents for imaging-guided photothermal cancer treatment.

Formation mechanisms of hollow manganese hexacyanoferrate particles and construction of a multiple-shell structure

Formation mechanisms of hollow manganese hexacyanoferrate (Mn-HCF) particles have been investigated. Mn-HCF particles, which were precipitated by mixing an aqueous solution of K3[Fe(CN)6] with MnCl2 in the presence of sodium citrate, could be converted into a hollow structure just by washing with distilled water. The powder X-ray diffractometry suggested that the as-prepared particle has a core/shell morphology with different crystal structures: cubic-core and monoclinic-shell. The time evolutions of the particle size and shell thickness indicated that the core was rapidly (but not instantaneously) formed at the initial stage of the precipitation process, followed by a slower shell growth. In addition, the solubility of the cubic core was estimated to be about 2.5 times higher than that of the monoclinic shell, resulting in the preferential dissolution of the interior of the particle by the washing process. The formation procedure has been used to construct multiple-shell hollow Mn-HCF particles containing up to quadruple separated nesting shells by associating an additional growth technique.

Laser-induced optothermal response of gold nanoparticles: From a physical viewpoint to cancer treatment application

Gold nanoparticles (GNPs)-based photothermal therapy (PTT) is a promising minimally invasive thermal therapy for the treatment of focal malignancies. Although GNPs-based PTT has been known for over two decades and GNPs possess unique properties as therapeutic agents, the delivery of a safe and effective therapy is still an open question. This review aims at providing relevant and recent information on the usage of GNPs in combination with the laser to treat cancers, pointing out the practical aspects that bear on the therapy outcome. Emphasis is given to the assessment of the GNPs' properties and the physical mechanisms underlying the laser-induced heat generation in GNPs-loaded tissues. The main techniques available for temperature measurement and the current theoretical simulation approaches predicting the therapeutic outcome are reviewed. Topical challenges in delivering safe thermal dosage are also presented with the aim to discuss the state-of-the-art and the future perspective in the field of GNPs-mediated PTT.

Redox/photo dual-responsive, self-targeted, and photosensitizer-laden bismuth sulfide nanourchins for combination therapy in cancer

Targeted and stimuli-sensitive nanobombs for the release of therapeutic agents after laser irradiation of the tumor site are gaining widespread attention as personalized anticancer regimens. In this study, redox and photo dual-responsive, folate receptor-targeted nanourchin carriers for chemo-, photodynamic, and photothermal therapy were constructed by the amalgamation of an outer layer of polyethylene glycol (PEG)-S-S-methotrexate (MTX) and an inner core of indocyanine green (ICG)-loaded bismuth sulfide (Bi2S3) nanoparticles for cancer treatment. MTX introduces the carrier to folate receptors resulting in the internalization of nanoparticles into cancer cells, specifically and increasingly. In the reducing environment inside cancer cells, MTX was cleaved, resulting in a burst release that effectively inhibited tumor growth. Simultaneously, the fusion of Bi2S3 and ICG in the inner core absorbed energy from a near-infrared radiation (NIR) laser to generate heat and reactive oxygen species, which further ablated the tumors and synergistically enhanced the anticancer activity of MTX. These results indicate the successful preparation of combined nanourchins (NUs) showing GSH-induced and laser-responsive release of MTX and ICG, accompanied by hyperthermia via Bi2S3 and ICG. Effective in vitro cellular internalization, cellular cytotoxicity, and pro-apoptotic behavior of the nanosystem were achieved through a targeting, redox, and NIR-responsive combination strategy. In vivo biodistribution and photothermal imaging also revealed tumor-selective and -retentive, as well as thermally responsive attributes. Ultimately, this in vivo antitumor study shows an effective tumor ablation by these nanourchins without affecting the vital organs. Our findings indicate that using these targeted redox- and laser-responsive combination therapeutic carriers can be a promising strategy in folate receptor-expressing tumors.

Dual catalytic cascaded nanoplatform for photo/chemodynamic/starvation synergistic therapy

In this study, manganese dioxide (MnO₂) was attached to prussian blue (PB) by a one-pot method to prepare PBMO. Then, the GOD was loaded onto PBMO through the electrostatic interaction of hyaluronic acid (HA) to form tumor-targeted nanoplatform (PBMO-GH). Hydrogen peroxide (H₂O₂) and gluconic acid were produced through the GOD-catalyzed enzymatic reaction. Meanwhile, PB could not only catalyze H₂O₂ for oxygen generation to further promote glucose consumption but also possess the property of photothermal conversion. As a result, glucose was continuously consumed to achieve the starvation therapy (ST), and the photothermal therapy (PTT) could be realized under near-infrared (NIR) light. Besides, the Mn²⁺ generated by the reaction of MnO₂ with glutathione (GSH) could exert Fenton-like reaction to produce highly toxic hydroxyl radicals (·OH) from H₂O₂, which thereby realized self-reinforcing chemodynamic therapy (CDT). In vitro and in vivo experiments demonstrated that PBMO-GH could effectively inhibit the growth of tumor cells via ST/CDT/PTT synergistic effect. Therefore, the as-prepared nanoplatform for multi-modal therapy will provide a promising paradigm for overcoming cancer.

Prussian blue nanozyme-mediated nanoscavenger ameliorates acute pancreatitis via inhibiting TLRs/NF-κB signaling pathway

Rationale: Acute pancreatitis (AP) is a serious acute condition affecting the abdomen and shows high morbidity and mortality rates. Its global incidence has increased in recent years. Inflammation and oxidative stress are potential therapeutic targets for AP. This study was conducted to investigate the intrinsic anti-oxidative and anti-inflammatory effects of Prussian blue nanozyme (PBzyme) on AP, along with its underlying mechanism. Methods: Prussian blue nanozymes were prepared by polyvinylpyrrolidone modification method. The effect of PBzyme on inhibiting inflammation and scavenging reactive oxygen species was verified at the cellular level. The efficacy and mechanism of PBzyme for prophylactically treating AP were evaluated using the following methods: serum testing in vivo, histological scoring following hematoxylin and eosin staining, terminal deoxynucleotidyl transferase dUTP nick end labeling fluorescence staining, polymerase chain reaction array, Kyoto Encyclopedia of Genes and Genomes analysis and Western blotting analysis. Results: The synthetic PBzyme showed potent anti-oxidative and anti-inflammatory effects in reducing oxidative stress and alleviating inflammation both in vitro and in vivo in the prophylactic treatment of AP. The prophylactic therapeutic efficacy of PBzyme on AP may involve inhibition of the toll-like receptor/nuclear factor-κB signaling pathway and reactive oxygen species scavenging. Conclusion: The single-component, gram-level mass production, stable intrinsic biological activity, biosafety, and good therapeutic efficacy suggest the potential of PBzyme in the preventive treatment of AP. This study provides a foundation for the clinical application of PBzyme.

Macrophage-Membrane-Camouflaged Disintegrable and Excretable Nanoconstruct for Deep Tumor Penetration

The consolidation of nanovectors with biological membranes has recently been a subject of interest owing to the prolonged systemic circulation time and delayed clearance by the reticuloendothelial system of such systems. Among the different biomembranes, the macrophage membrane has a similar systemic circulation time, with an additional chemotactic aptitude, targeting integrin proteins. In this study, we aimed to establish a laser-activated, disintegrable, and deeply tumor-penetrative nanoplatform. We used a highly tumor-ablative and laser-responsive disintegrable copper sulfide nanoparticle, loaded it with paclitaxel, and camouflaged it with the macrophage membrane for the fabrication of PTX@CuS@MMNPs. The in vitro paclitaxel release profile was favorable for release in the tumor microenvironment, and the release was accelerated after laser exposure. Cellular internalization was improved by membrane encapsulation. Cellular uptake, cytotoxicity, reactive oxygen species generation, and apoptosis induction of PTX@CuS@MMNPs were further improved upon laser exposure, and boosted permeation was achieved by co-administration of the tumor-penetrating peptide iRGD. In vivo tumor accumulation, tumor inhibition rate, and apoptotic marker expression induced by PTX@CuS@MMNPs were significantly improved by laser irradiation and iRGD co-administration. PTX@CuS@MMNPs induced downregulation of cellular proliferation and angiogenic markers but no significant changes in body weight, survival, or significant toxicities in vital organs after laser exposure, suggesting their biocompatibility. The disintegrability of the nanosystem, accredited to biodegradability, favored efficient elimination from the body. In conclusion, PTX@CuS@MMNPs showed promising traits in combination therapies for excellent tumor eradication.

The Application of Prussian Blue Nanoparticles in Tumor Diagnosis and Treatment

Prussian blue nanoparticles (PBNPs) have attracted increasing research interest in immunosensors, bioimaging, drug delivery, and application as therapeutic agents due to their large internal pore volume, tunable size, easy synthesis and surface modification, good thermal stability, and favorable biocompatibility. This review first outlines the effect of tumor markers using PBNPs-based immunosensors which have a sandwich-type architecture and competitive-type structure. Metal ion doped PBNPs which were used as T1-weight magnetic resonance and photoacoustic imaging agents to improve image quality and surface modified PBNPs which were used as drug carriers to decrease side effects via passive or active targeting to tumor sites are also summarized. Moreover, the PBNPs with high photothermal efficiency and excellent catalase-like activity were promising for photothermal therapy and O2 self-supplied photodynamic therapy of tumors. Hence, PBNPs-based multimodal imaging-guided combinational tumor therapies (such as chemo, photothermal, and photodynamic therapies) were finally reviewed. This review aims to inspire broad interest in the rational design and application of PBNPs for detecting and treating tumors in clinical research.

A Hepatocellular Carcinoma Targeting Nanostrategy with Hypoxia-Ameliorating and Photothermal Abilities that, Combined with Immunotherapy, Inhibits Metastasis and Recurrence

Hepatocellular carcinoma (HCC) is a common and highly malignant tumor that is prone to recurrence and metastasis and has no effective treatment. Unsurprisingly, its prognosis is quite poor; early detection methods and effective low-toxicity treatments are urgently needed. To achieve these goals, we designed a multifunctional, U.S. Food and Drug Administration-approved Prussian blue (PB) nanoparticle (NP) with a porous metal organic frame loaded with sorafenib (SF), conjugated with HCC-specific targeting peptide SP94 and the near-infrared dye cyanine (Cy)5.5. These NPs are amenable to multimodal imaging for dynamic monitoring of their biodistribution and tumor-targeting effects. The SP94-PB-SF-Cy5.5 NPs achieved targeted delivery and controlled SF release and exhibited good photothermal effects. In this strategy, photothermal therapy and SF treatment complement each other, reducing the side effects of SF and achieving a therapeutic effect without local tumor recurrence. In addition, the catalase-like ability of the NPs alleviates tumor hypoxia, and their photothermal effects induce immunogenic cell death, leading to the release of tumor-associated antigens. These effects combine to trigger an antitumor immune response; the NPs also displayed promising inhibitory effects on tumor metastasis and recurrence and produced an abscopal effect and long-term immunological memory when combined with antiprogrammed death-ligand 1 (PD-L1) immunotherapy. These safe, multifunctional NPs represent a valuable treatment option for HCC. In addition, this next-generation treatment model may provide some ideas for the management of HCC and other cancers.