Direct Synthesis of Prussian Blue Nanoparticles in Liposomes Incorporating Natural Ion Channels for Cs+ Adsorption and Particle Size Control

Nanosized Prussian blue and its analogs for bioimaging and cancer theranostics

Prussian blue (PB) nanoparticles (NPs) and Prussian blue analogs (PBAs) can form metal-organic frameworks through the programmable coordination of ferrous ions with cyanide. PB and PBAs represent a burgeoning class of hybrid functional nano-systems with a wide-ranging application spectrum encompassing biomedicine, cancer diagnosis, and therapy. A comprehensive overview of recent advancements is crucial for gaining insights for future research. In this context, we reviewed the synthesis techniques and surface modification strategies employed to tailor the dimensions, morphology, and attributes of PB NPs. Subsequently, we explored advanced biomedical utilities of PB NPs, encompassing photoacoustic imaging, magnetic resonance imaging, ultrasound (US) imaging, and multimodal imaging. In particular, the application of PB NPs-mediated photothermal therapy, photodynamic therapy, and chemodynamic therapy to cancer treatment was reviewed. Based on the literature, we envision an evolving trajectory wherein the future of Prussian blue-driven biological applications converge into an integrated theranostic platform, seamlessly amalgamating bioimaging and cancer therapy. STATEMENT OF SIGNIFICANCE: Prussian blue, an FDA-approved coordinative pigment with a centuries-long legacy, has paved the way for Prussian blue nanoparticles (PB NPs), renowned for their remarkable biocompatibility and biosafety. These PB NPs have found their niche in biomedicine, playing crucial roles in both diagnostics and therapeutic applications. The comprehensive review goes beyond PB NP-based cancer therapy. Alongside in-depth coverage of PB NP synthesis and surface modifications, the review delves into their cutting-edge applications in the realm of biomedical imaging, encompassing techniques such as photoacoustic imaging, magnetic resonance imaging, ultrasound imaging, and multimodal imaging.

Sustainable Coordination Polymer-Based Catalyst and Its Application in the Nitroaromatic Hydrogenation under Mild Conditions

Nitroarene reduction has played a crucial role in the environment remediation and public health. However, few research studies have been undertaken regarding the use of infinite coordination polymer-based catalysts in this process. Herein, we are looking for a way to catalyze the reduction of nitroarenes using a new and well-designed coordination polymer-based palladium catalyst. The Co-BDC-NH₂ coordination polymer was prepared through a co-precipitation reaction between 2-amino-1,4-benzenedicarboxylic acid as a linker and the cobalt cation as a node. Functionalization of the prepared Co-BDC-NH₂ with 2-pyridinecarboxaldehyde and subsequent metallation with a Pd cation led to the formation of the final catalyst, i.e., Co-BDC-NH₂-py-Pd. It has been specified that palladium species substantially contribute to the reduction of nitroarenes in the presence of hydrazine hydrate (N₂H₄·H₂O). The highest conversion (100%) of nitroarenes to the corresponding amines was achieved under relatively mild conditions. This heterogeneous catalyst was able to catalyze the reduction of nitroarenes to desired products without changing other substituents. The reusability and stability of the catalyst were confirmed through four consecutive reduction tests without a major decrease in catalytic activity.

A Prussian blue alginate microparticles platform based on gas-shearing strategy for antitumor and antibacterial therapy

Prussian blue (PB) with distinct hollow mesoporous structure and favorable properties has captured the attention of extensive biomaterial researchers. However, there is an unmet need for biocompatible PB microparticles with recyclability fabricated by a facile method. Herein, a size-controlled PB alginate microparticles (PBAMs) generated by a one-step and large batch production gas-shearing strategy. With the characteristic of porous and surface-modifiable, PBAMs used as vehicles may effectively load and release drug to improve the therapeutic efficacy. Meanwhile, Fe²⁺ in PBAMs exerts a catalyze for chemodynamic therapy (CDT) to produce reactive oxygen species (ROS), which synergizes with the photothermal therapy (PTT) induced by PB particles with effective photothermal conversion, achieving active tri-modality combination antitumor and antibacterial. The new concept for the low-cost and facile preparation of biocompatible PBAMs here illustrated opens a novel pathway toward the effective multifunctional platform.

Prussian Blue: A Safe Pigment with Zeolitic-Like Activity

Prussian blue (PB) and PB analogues (PBA) are coordination network materials that present important similarities with zeolites concretely with their ability of adsorbing cations. Depending on the conditions of preparation, which is cheap and easy, PB can be classified into soluble PB and insoluble PB. The zeolitic-like properties are mainly inherent to insoluble form. This form presents some defects in its cubic lattice resulting in an open structure. The vacancies make PB capable of taking up and trapping ions or molecules into the lattice. Important adsorption characteristics of PB are a high specific area (370 m2 g-1 determined according the BET theory), uniform pore diameter, and large pore width. PB has numerous applications in many scientific and technological fields. PB are assembled into nanoparticles that, due to their biosafety and biocompatibility, can be used for biomedical applications. PB and PBA have been shown to be excellent sorbents of radioactive cesium and radioactive and nonradioactive thallium. Other cations adsorbed by PB are K+, Na+, NH4+, and some divalent cations. PB can also capture gaseous molecules, hydrocarbons, and even luminescent molecules such as 2-aminoanthracene. As the main adsorptive application of PB is the selective removal of cations from the environment, it is important to easily separate the sorbent of the purified solution. To facilitate this, PB is encapsulated into a polymer or coats a support, sometimes magnetic particles. Finally, is remarkable to point out that PB can be recycled and the adsorbed material can be recovered.

Finely tuned Prussian blue-based nanoparticles and their application in disease treatment

The Prussian blue (PB) based nanostructure is a mixed-valence coordination network with excellent biosafety, remarkable photothermal effect and multiple enzyme-mimicking behaviours. Compared with other nanomaterials, PB-based nanoparticles (NPs) exhibit several unparalleled advantages in biomedical applications. This review begins with the chemical composition and physicochemical properties of PB-based NPs. The tuning strategies of PB-based NPs and their biomedical properties are systemically demonstrated. Afterwards, the biomedical applications of PB-based NPs are comprehensively recounted, mainly focusing on treatment of tumors, bacterial infection and inflammatory diseases. Finally, the challenges and future prospects of PB-based NPs and their application in disease treatment are discussed.

Synthesis, Catalytic Properties and Application in Biosensorics of Nanozymes and Electronanocatalysts: A Review

The current review is devoted to nanozymes, i.e., nanostructured artificial enzymes which mimic the catalytic properties of natural enzymes. Use of the term "nanozyme" in the literature as indicating an enzyme is not always justified. For example, it is used inappropriately for nanomaterials bound with electrodes that possess catalytic activity only when applying an electric potential. If the enzyme-like activity of such a material is not proven in solution (without applying the potential), such a catalyst should be named an "electronanocatalyst", not a nanozyme. This paper presents a review of the classification of the nanozymes, their advantages vs. natural enzymes, and potential practical applications. Special attention is paid to nanozyme synthesis methods (hydrothermal and solvothermal, chemical reduction, sol-gel method, co-precipitation, polymerization/polycondensation, electrochemical deposition). The catalytic performance of nanozymes is characterized, a critical point of view on catalytic parameters of nanozymes described in scientific papers is presented and typical mistakes are analyzed. The central part of the review relates to characterization of nanozymes which mimic natural enzymes with analytical importance ("nanoperoxidase", "nanooxidases", "nanolaccase") and their use in the construction of electro-chemical (bio)sensors ("nanosensors").

Prussian blue nanoparticles: synthesis, surface modification, and biomedical applications

Prussian blue nanoparticles (PBNPs) are a nanomaterial that presents unique properties and an excellent biocompatibility. They can be synthesized in mild conditions and can be derivatized with polymers and/or biomolecules. PBNPs are used in biomedicine as therapy and diagnostic agents. In biomedical imaging, PBNPs constitute contrast agents in photoacoustic and magnetic resonance imaging (MRI). They are a good adsorbent to be used as antidotes for poisoning with cesium and/or thallium ions. Moreover, the ability to convert energy into heat makes them useful photothermal agents (PAs) in photothermal therapy (PTT) or as nonantibiotic substances with antibacterial properties. Finally, PBNPs can be both reduced to Prussian white and oxidized to Prussian green. A large window of redox potential exists between reduction and oxidation, which result in the enzyme-like characteristics of these NPs.

Engineered proteoliposome transporter for treatment of cesium contaminated water

Radioactive cesium (¹³⁷Cs) released from nuclear power plants and nuclear accidents continues to be a worldwide concern, and its removal from water remains a difficult problem. Here, we present the development of an innovative method to remove Cs⁺ present at low concentrations in water. To achieve this, a proteoliposome transporter was engineered, composed of a membrane-bound potassium uptake protein, Kup from E. coli, which was reconstituted into a liposome vesicle. Cs⁺ removal (10-100 µg/L) was demonstrated by incubating the constructed proteoliposome in lab-fortified water, followed by ultracentrifugation to remove captured Cs⁺. Inductively coupled plasma mass spectrometry (ICP-MS) results from testing water spiked with 100 µg/L Cs⁺ revealed that adding increasing volumes of proteoliposome solution (containing 0.015-1.2 mg of Kup membrane transporter) resulted in 0.29-12.7% removal in a linear fashion. Proteoliposome addition (containing 0.015-0.3 mg of Kup membrane transporter) to water spiked with 10 µg/L Cs⁺ resulted in 0.65-3.43% removal, while removal by protein-free liposomes was negligible at 0.03%. These results suggest that Kup transporters inserted into the liposomes are mainly responsible for the removal efficiencies. Consequently, a desired removal efficiency can be achieved by adding a higher volume of constructed proteoliposome and subsequently higher mg of Kup transporter to the contaminated water. This provides new insight on the effectiveness and applicability of proteoliposome transporters, and an alternative and a novel contribution to emerging technologies in removing cesium or other metal contaminants undergoing transmembrane transport.

Electrochemical Adsorption of Cs+ Ions on H-Todorokite Nanorods

In this work, manganese oxide with a 3 × 3 tunnel structure was synthesized. Mg-todorokite was treated with HNO₃ to obtain H-todorokite, which was used as an electrode for adsorption of Cs⁺ from aqueous solution by an electrochemical reaction. H-todorokite was electrochemically reduced to lower oxidation state to enhance its negative charge and simultaneously increase the amount of cations because of the charge compensation. The Cs⁺ adsorption on H-todorokite was completed by a coupled electrochemical reaction (the redox reaction between Mn³⁺ and Mn⁴⁺) and an ion-exchange reaction between Cs⁺ and H⁺ ions. Cyclic voltammetry measurements at different pHs and Cs⁺ concentrations were performed. H-todorokite revealed high electrochemical adsorption capacity for Cs⁺ because of the high crystallinity and stability of the materials, which reached 6.0 mmol g^-1 in 0.1 mol·L^-1 Na₂SO₄ solution.

Facile Synthesis of Novel Prussian Blue-Lipid Nanocomplexes

Prussian blue (PB) is known for its multiple applications ranging from fine arts to therapeutics. More recently, PB nanoparticles have been pointed to as appealing photothermal agents (PA) when irradiated with wavelengths corresponding to the biological windows, namely regions located in the near infrared (NIR) zone. In addition, the combination of PB with other components such as phospholipids boosts their therapeutical potential by facilitating, for instance, the incorporation of drugs becoming suitable drug delivery systems. The novelty of the research relies on the synthesis procedure and characterization of hybrid lipid-PB nanoparticles with a high yield in a friendly environment suitable for photothermal therapy. This goal was achieved by first obtaining insoluble PB coated with oleylamine (OA) to facilitate its combination with lipids. The resulting lipid-PB complex showed a monomodal distribution of sizes with an overall size of around 100 nm and a polydispersity index of about 0.200. It highlights one critical step in the synthesis procedure that is the shaking time of the mixture of PB-OA nanoparticles with the lipid, which was found to be 48 h. This time assured homogeneous preparation without the need of further separation stages. Samples were stable for more than three months under several storage conditions.

Progress in Applications of Prussian Blue Nanoparticles in Biomedicine

Prussian blue nanoparticles (PBNPs) with favorable biocompatibility and unique properties have captured the attention of extensive biomedical researchers. A great progress is made in the application of PBNPs as therapy and diagnostics agents in biomedicine. This review begins with the recent synthetic strategies of PBNPs and the regulatory approaches for their size, shape, and uniformity. Then, according to the different properties of PBNPs, their application in biomedicine is summarized in detail. With modifiable features, PBNPs can be used as drug carriers to improve the therapeutic efficacy. Moreover, the exchangeable protons and adsorbability enable PBNPs to decontaminate the radioactive ions from the body. For biomedical imaging, photoacoustic and magnetic resonance imaging based on PBNPs are summarized, as well as the strategies to improve the diagnostic effectiveness. The applications related to the photothermal effects and nanoenzyme activities of PBNPs are described. The challenges and critical factors for the clinical translation of PBNPs as multifunctional theranostic agents are also discussed. Finally, the future prospects for the application of PBNPs are considered. The aim of this review is to provide a better understanding and key consideration for rational design of this increasingly important new paradigm of PBNPs as theranostics.