Multimodal Prussian blue analogs as contrast agents for X-ray computed tomography

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.

Manganese complexes and manganese-based metal-organic frameworks as contrast agents in MRI and chemotherapeutics agents: Applications and prospects

Manganese-based Metal-organic Frameworks (Mn-MOFs) represents a unique sub-class of MOFs with low toxicity, oxidative ability, and biocompatibility, which plays vital role in the application of this class of MOFs in medical field. Mn-MOFs show great potential in biomedical applications, and has been extensively studied as compared to other MOFs in transition metal series. They are important in medical applications because Mn(II) possess large electron spin number and longer electron relaxation time. They display fast water exchange rate and could be employed as a potential MRI contrast agent because of their strong targeting ability. Manganese complexes with different ligands also display prospective applications in area such as carrier for drug targeting in anti-tumor and antimicrobial therapy. In the review presented herewith, the application of Mn-based complexes and Mn-MOFs have been emphasized in the area such as imaging viz. MRI, multimodal imaging, antitumor activities such as chemodynamic therapy, photodynamic therapy, sonodynamic therapy and antimicrobial applications. Also, how rational designing and syntheses of targeted Mn-based complexes and Mn-MOFs can engender desired applications.

CuICuII and AgIp-isocyanobenzoates as novel 1D semiconducting coordination oligomers

Two novel semiconducting coordination oligomers with 1D chain structures, namely [H0.07 CuI0.65CuII0.14(μ-p-CNC6H4CO2)·0.9H2O]n and [Ag(μ-p-CNC6H4CO2)]n, were obtained and characterized by XRD powder patterns, and XPS, EPR, UV-vis-NIR, IR and Raman spectroscopy. According to XRD analysis, CuICuII-ICNBA is an amorphous solid, while AgI-ICNBA crystalizes with a monoclinic unit cell in the C2/c space group (Z = 4). The composition and further information of CuICuII-ICNBA were obtained from the spectroscopic data. In correspondence with the quantification of terminal groups from high-resolution XPS spectra, CuICuII-ICNBA and AgI-ICNBA are composed of an average of 9 and 7 monomer units, respectively, resulting in 1D-oligomers. The spectroscopic evidence indicates that CuICuII-ICNBA is better described as a non-stoichiometric coordination oligomer (where non-integer ratios of metal ions can be accommodated), while AgI-ICNBA is stoichiometric. In both materials, each metal center is linked by two μ-η1:η1-p-isocyanobenzoate ligands forming microfibers of around 120 nm (CuICuII-material) and 310 nm (AgI-material) in average diameters with optical band gaps of 2.60 eV and 2.17 eV, respectively.

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.

Large-scale synthesis of monodisperse Prussian blue nanoparticles for cancer theranostics via an "in situ modification" strategy

Background

The intrinsic properties of Prussian blue (PB) nanoparticles make them an attractive tool in nanomedicine, including magnetic resonance imaging (MRI), photoacoustic imaging (PAI), and photothermal therapy (PTT) properties. However, there still remains the challenge of their poor dispersible stability in the physiological environment. In this study, we developed an efficient hydrothermal method to address the poor dispersible stability of PB nanoparticles in the physiological environment.

Materials and methods

The concentration of H⁺, the mass of polyvinylpyrrolidone (PVP), and iron sources (K₃[Fe(CN)₆]) are very vital in the preparation of PB nanoparticles. Through exploring the preparation process, optimized PB nanoparticles (OPBs) with excellent physiological stability were prepared. Hydrodynamic diameter and UV-vis absorption properties were measured to verify the stability of the prepared OPBs. Properties of dual-mode imaging, including MRI/PAI, and PTT of OPBs were investigated both in vitro and in vivo. In addition, the in vivo biosafety of OPBs was systematically assessed.

Results

OPBs were stable in different environments including various media, pH, and temperatures for at least 90 days, indicating that they are suitable for biomedical application via intravenous administration and easily stored in a robust environment. Compared with other research into the synthesis of PB nanoparticles, the “in situ modification” synthesis of PB nanoparticles had advantages, including a simple process, low cost, and easy mass preparation. OPBs showed no significant signs of toxicity for 90 days. As a proof of concept, the OPBs served as dual-mode image contrast agents and photothermal conversion agents for cancer diagnosis and therapy both in vitro and in vivo.

Conclusion

Our findings suggest a facile but efficient strategy with low cost to address the poor dispersible stability of PB nanoparticles in physiological environments. This will promote the development of further clinical transformations of PB nanoparticles, especially in cancer theranostics.