Prussian Blue and Its Analogues: From Properties to Biological Applications

Prussian Blue and Its Analogues: From Properties to Biological Applications

A set of studies have demonstrated the properties of PB and its analogues such as photothermal ability, reactive oxygen species scavenging and adsorption ability. Many outstanding researches are published to set a basis for further application in clinic. The properties and biological applications of PB as well as its analogue are reviewed, and hope arouse more interests of researchers.


Abstract

The utilization of metal organic framework (MOF) nanocomposites in various biomedical applications has been widely studied because of their unique properties. In recently years, Prussian blue (PB) is widely used in clinical studied due to its biosafety, which has already been approved by USA Food and Drug Administration (FDA). Therefore, it is great urgent to systematically summarize the resent progress to better serve the broad community of researchers. This review focuses on the properties of PB and PB analogues (PBA), and their applications in biological field. A systemic introduction of the properties is presented, including abilities of photothermal, scavenging of reactive oxygen species and adsorption. A variety of biomedical applications, such as tumor therapy, anti-bacterial infection, biosensor, bioimaging, excretion, ischemic stroke treatment, etc. have been discussed as well. Furthermore, the challenges, key factors, and the prospects in the clinical transformation of PB or PBA are simultaneously discussed. This review will provide reference and guidance for the design and application of PB and PBA in the future.

Preparation and Utilization of a Comb‐Like Polycarboxylate Dispersant for Organic Pigment

Preparation and Utilization of a Comb-Like Polycarboxylate Dispersant for Organic Pigment

A series of carboxylate comb-like copolymer dispersants, SAM-(m)PEG, were synthesized via polymerization and esterification to disperse and stabilize C.I. Pigment Yellow 180 (PY 180). Among them, SAM-PEG6002 displayed the best performance; the average particle size (Z-average) and PDI of PY 180 could reach 264.6 nm and 0.089, respectively, when applied. Furthermore, the results of the optical property experiments demonstrated the versatile applicability of SAM-PEG6002.


Abstract

As a novel form of carboxylate comb-like copolymers, SAM-(m)PEG was prepared by polymerizing styrene (S), acrylic (A), and maleic anhydride (M) to obtain a random copolymer labeled SAM. SAM was then esterified using either polyethylene glycol (PEG) or methyl PEG (mPEG), a waterborne polymer dispersant for dispersing and stabilizing C.I. Pigment Yellow 180 (PY 180). The structures of SAM-(m)PEG and the ground suspension of PY 180 were characterized by Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, scanning electron microscopy (SEM), a nanoparticle size analysis, and viscometry. The effects of different branch chains, synthetic formulas, and grinding conditions on the dispersibility of SAM-(m)PEG were evaluated. In addition, the optical properties of the pigments were investigated after ultrafine grinding. The adsorption mechanism between the SAM-(m)PEG dispersants and PY 180 particles is also discussed. SAM-PEG6002 outperformed the other SAM-(m)PEG dispersants owing to its excellent dispersion and stability. When used as the dispersant, the average particle size (Z-average) of PY 180 after grinding was 264.6 nm, and the particle size distribution became narrow (PDI=0.089). Moreover, SAM-PEG6002 effectively maintained the color performance of the pigment, and the product was successfully applied to the pigment coating. Therefore, SAM-PEG6002 is an effective waterborne polymer dispersant for organic pigments.

Understanding Critical Aspects of Liposomal Synthesis for Designing the Next Generation Targeted Drug Delivery Vehicle

Understanding Critical Aspects of Liposomal Synthesis for Designing the Next Generation Targeted Drug Delivery Vehicle

We optimized multiple process paramters and certain intrinsic factors to develop liposomes for drug delivery; liposomes were also characterized by various analytical techniques. This study provides a mechanistic insight into the synthesis method, ascertains roles to every factor, and allows modification of appropriate parameters to synthesize liposomes with desired specifications.


Abstract

We identified process parameters of the thin film hydration technique and intrinsic factors to synthesize liposomes for drug delivery. The thin film formation step impacted the nature of the lipid layer, and we optimized 240 RPM rotation speed, 700 mm of Hg vacuum pressure, and 2 ml of chloroform as the organic solvent. The hydration step controlled the particle specifications, and we optimized 270 RPM rotation speed, PBS as the hydrating medium, and 1 h hydration time. We obtained a comparatively smaller liposomal population with a lower size distribution just after hydrating the lipid layer that required milder downsizing steps −10 extrusion passes through a single polycarbonate membrane. The intrinsic factors including the concentrations and molar ratio of lipids affected the synthesis steps and the particle specifications. Characterization of liposomes by analytical techniques confirmed the synthesis of a monodisperse population with hydrodynamic diameter<150 nm, moderate stability, spherical morphology, and high thermal and storage stability. This comprehensive study defines the role of every parameter, provides a mechanistic insight into synthesis that is supported by experimental data, and helps tune specific parameters to synthesize liposomes for drug delivery or any application with desired specifications.

Enhanced Yield of Sodium Alginate Extracted from Padina gymnospora Using a Greener Microwave and Ultrasound Hybrid System

Enhanced Yield of Sodium Alginate Extracted from Padina gymnospora Using a Greener Microwave and Ultrasound Hybrid System

A high yield of sodium alginate with high mannuronic content and low viscosity was extracted by using a greener and cleaner organic acid pre-treatment in the presence of the eco-friendly microwave and ultrasound techniques for a sustainable extraction route.


Abstract

In this study, alginate was extracted from Padina gymnospora (PG) by applying the sequential combination of microwaves followed by ultrasounds (at low power and amplitude settings) using an organic acid pre-treatment. The optimum alginate yield was investigated by varying the type of acid (oxalic and formic) and seaweed particle size range (0.295–0.495 and 0.146–0.246 mm). The extracted sodium alginate was then characterised in terms of FTIR, 1H-NMR, M/G ratio, viscosity and colour. The synergistic effect of the microwave-ultrasound hybrid system for short timeframes (15 min each) successfully improved the alginate yield without compromising its structural composition, while allowing for a milder and greener organic acid to be used for the acid pre-treatment. The highest alginate yield (~64 %) was obtained using formic acid and the smaller particle size range (0.146–0.246 mm). The latter thus highlights the importance of particle size reduction and optimisation. FTIR, NMR and viscosity analyses revealed a low guluronic acid content of alginate with a high M/G ratio (7.7±1.0–9.3±0.1) and low viscosity (2.92±0.09–3.05±0.06 cP), which was found to be inherent to the species used. The proposed novel method therefore opens prospects for the industry since it is both environmentally and economically sustainable.

One‐Pot Synthesis of β‐Ketoesters from Aryl Methyl Ketone via Ketene Dithioacetal

One-Pot Synthesis of β-Ketoesters from Aryl Methyl Ketone via Ketene Dithioacetal

Activated methylene group-containing compound was synthesized from functionalized acetophenone through ketene dithioacetals using ethanolic KOH.


Abstract

We have discovered base-mediated conversion of 3,3-bis(methylthio)-1-arylprop-2-en-1-ones to versatile active methylene compounds (β-keto esters). A series of products were isolated and characterized as a mixture of keto-enol form. We have modified the method and synthesized the active methylene compounds (β-keto esters) directly from aryl methyl ketone via ketene dithioacetal intermediate (not isolated) by stepwise reactions in one pot. Most of the one-pot reactions also provided excellent yields. In addition to aryl methyl ketones, we also tested cyclopropyl methyl ketone as a source of an aliphatic ketone, and under similar reaction conditions, ethyl 3-cyclopropyl-3-oxopropanoate was afforded.

Discovery of a dual‐target inhibitor of CDK7 and HDAC1 that induces apoptosis and inhibits migration in colorectal cancer

Aberrant expression or dysfunction of Cyclin-dependent kinase 7(CDK7) and Histone deacetylase 1 (HDAC1) are associated with the occurrence and progression of various cancers. In this study, we developed a series of dual-target inhibitors by designing and synthesizing compounds that incorporate the pharmacophores of THZ2 and SAHA. The most potent dual-target inhibitor displayed robust inhibitory activity against several types of cancer cells and demonstrated promising inhibitory effects on both CDK7 and HDAC1. After further mechanistic studies, it was discovered that this inhibitor effectively arrested HCT-116 cells at the G2 phase and induced apoptosis. Additionally, it also significantly hindered the migration of HCT-116 cells and exhibited notable anti-tumor effects. These findings offer strong support for the development of dual-target inhibitors of CDK7 and HDAC1 and provide a promising avenue for future cancer therapy.

Moving out of the CF3‐land: synthesis, receptor affinity and in silico studies of NK1‐receptor ligands containing pentafluorosulfanyl (SF5) group

The NK1 receptor (NK1R) is a molecular target for both approved and experimental drugs intended for a variety of conditions, including i.a. emesis, pain or cancers. While contemplating modifications to the typical NK1R pharmacophore, we wondered whether the CF3 groups common for many NK1R ligands, could be replaced with some other moiety. Our attention was drawn by the SF5-group, and so we designed, synthesized and tested for NK1R affinity ten novel SF5-containing compounds. All the novel analogues exhibit detectable NK1R binding, with the best of them, compound 5a, binding only slightly worse (IC50 = 34.3 nM) than the approved NK1R-targeting drug, aprepitant (IC50 = 27.7 nM). Molecular docking provided structural explanation of SAR. According to our analysis, the SF5 group in our compounds occupies a position similar to that of one of CF3 groups of aprepitant as found in the crystal structure. Additionally, we checked on whether the docking scoring function or energies derived from Fragment Molecular Orbital quantum chemical calculations may be helpful in explaining and predicting the experimental receptor affinities for our analogues. Both these methods produce moderately good results. Overall, this is the first demonstration of the utility of the SF5-group in the design of NK1R ligands.

Protein–Porphyrin Complex Photosensitizers for Anticancer and Antimicrobial Photodynamic Therapies

Photodynamic therapy (PDT) efficiently induces apoptosis through visible-light irradiation of photosensitizers (PSs) within tumors and microbial cells. Porphyrin analogues serve as widely utilized photosensitizing agents with their theranostic abilities being governed by molecular structures and central metal ions. However, these macrocyclic compounds tend to agglutinate and form stacks in aqueous environments, resulting in a loss of photochemical activity. To overcome this limitation, encapsulation within liposomes and polymer micelles enables the dispersion of porphyrins as monomolecular entities in aqueous solutions, preventing undesirable deactivation. Recently, the use reconstituted hemoproteins containing various metal-porphyrins and protein cages incorporating porphyrins have garnered significant interest as a new generation of biocompatible PSs. In this concept paper, we provide a comprehensive review of recent developments and trends of protein–porphyrin complex PSs for applications in anticancer and antimicrobial PDTs.

Phosphinine vs Pyridine in Luminescent Cu(I) Complex and Application in Lifetime‐Based Molecular Thermometer

Luminescent Cu(I) complexes have attracted significant interest due to their adjustable emission properties, diverse structures, and reasonable cost. In this work, two class of complexes, namely phosphinine and pyridine ligated Cu(I) complexes that differ by only one atom, were synthesized and characterized. Photophysical analysis and theoretical studies reveal an emissive phosphinine-localized triplet states for Cu(I) phosphinine complexes, and a temperature-dependent interplay between metal-to-ligand charge-transfer (MLCT) singlet and triplet states for Cu(I) pyridine complexes. In general, the Cu(I) phosphinine complexes exhibit a longer lifetime and greater temperature-dependent lifetime changes than the pyridine complexes. A molecular thermometer incorporating Cu(I) phosphinine complexes 2c as indicator was fabricated. This thermometer exhibits a rare linear correlation between temperature and lifetime ranging from 77–297 K with a high sensitivity of –13.5 μs K–1.

Anti‐inflammatory and antioxidant activity of Titanium dioxide nanotubes conjugated with Quercetin.

Inflammation is closely associated with cancer and leads to the formation of various malignancies. Quercetin is a naturally occurring flavonoid, with numerous pharmaceutical activities like anti-oxidant, anti-inflammatory, and anti-tumor effects. Due to its partial solubility in an aqueous solution, its consumption is limited. We recently showed the physicochemical characterization of titanium dioxide nanotubes (TNT) conjugated with quercetin and we found that quercetin conjugated with TNT enhances the anticancer activity in B16F10 cells and induced apoptosis.  In the present study, we stimulated the efficiency of quercetin conjugated with titanium dioxide nanotubes and studies their anti-oxidant, anti-inflammatory activity. TNT conjugated with quercetin (showed less cytotoxic effect towards RAW264.7 macrophages than quercetin alone. The inflammatory stimulation of RAW264.7 with LPS induced the pro-inflammatory cytokine IL-6 and inducible nitric synthase mRNA which were significantly inhibited by treating with TNT-Qu without causing any toxicity than quercetin and TNT alone. These results suggested that the potential of TNT conjugated with quercetin are better than quercetin and TNT alone and TNT may provide protection against inflammation by down regulating IL-6 and iNOS.