Prolonged release and shelf-life of anticoagulant sulfated polysaccharides encapsulated with ZIF-8

Paotianxiong polysaccharides potential prebiotics: Structural analysis and prebiotic properties

Paotianxiong (PTX) is a processing product of Aconitum carmichaelii Debx., often used as a tonic food daily. However, the structure and activity of the polysaccharide component that plays a major role still need to be determined. In our work, two new polysaccharides were purified from PTX and named PTXP-1 and PTXP-2. Structural analysis showed that PTXP-1 is a glucan with a molecular weight of 915 Da and a structure of 4)-α-D-Glcp-(1 → as the main chain. PTXP-2 is a glucose arabinoglycan with 4)-α-D-Glcp-(1 → as the main chain, containing 8 glycosidic bonds attached, and a molecular weight of 57.9KDa. In vitro probiotic experiments demonstrated that PTXP-1 could significantly promote probiotic growth and acid production. In vivo experiments demonstrated that both PTXP-1 and PTXP-2 exhibited significant effectiveness in promoting the growth of intestinal probiotics. These findings help expand the application of polysaccharide components extracted from tonic herbs as functional food ingredients.

Polydopamine-Mediated Metal-Organic Frameworks Modification for Improved Biocompatibility

Engineered nanomaterials are promising in biomedical application. However, insufficient understanding of their biocompatibility at the cellular and organic levels prevents their widely biomedical applications. Metal-organic frameworks (MOFs) have attracted increasing attention in recent years. In this work, zeolitic imidazolate framework-8 (ZIF-8) and polydopamine (PDA)-modified ZIF-8 are chosen as model nanomaterials due to its emergent role in nanomedicine. In vitro, the results demonstrate that the PDA coating greatly alleviates the cytotoxicity of ZIF-8 to RAW264.7, LO2, and HST6, which represent three different cell types in liver organs. Mechanistically, ZIF-8 entering into the cells can greatly induce the reactive oxygen species generation, which subsequently induces cell cycle delay and autophagy, ultimately leads to enhanced cytotoxicity. Further, human umbilical vein endothelial cells model and zebrafish embryos assay also confirm that PDA can compromise the ZIF-8 toxicity significantly. This study reveals that PDA-coated MOFs nanomaterials show great potential in nano-based drug delivery systems .

Degradation Kinetic Studies of BSA@ZIF-8 Nanoparticles with Various Zinc Precursors, Metal-to-Ligand Ratios, and pH Conditions

Nanosized zeolitic imidazolate framework particles (ZIF-8 nanoparticles [NPs]) have strong potential as effective carriers for both in vivo and in vitro protein drug delivery. Synthesis of ZIF-8 and stability of protein encapsulation within ZIF-8 are affected by several factors, notably the metal ion source and molar ratio. To systematically investigate these factors, we investigated such effects using BSA as a model test protein to synthesize BSA@ZIF-8 NPs at various metal-to-ligand (M:L) ratios. SEM, FTIR, XRD, and DLS were applied to characterize the morphology and structure of BSA@ZIF-8 NPs and their effects on protein loading capacity. Degradation kinetics and protein release behavior of BSA@ZIF-8 NPs were evaluated at pH 5.0 (to simulate the tumor environment) and pH 7.4 (to mimic the blood environment). Our objective was to define optimal combinations of the high protein loading rate and rapid release under varying pH conditions, and we found that (i) the yield of BSA@ZIF-8 NPs decreased as the M:L ratio increased, but the protein content increased. This highlights the need to strike a balance between cost-effectiveness and practicality when selecting ZIF-8 NPs with different molar ratios for protein-based drug formulation. (ii) BSA@ZIF-8 NPs exhibited cruciate flower-like shapes when synthesized using Zn(NO3)2 as the zinc precursor at M:L ratios of 1:16 or 1:20. In all other cases, the NPs displayed a regular rhombic dodecahedral structure. Notably, the release behavior of the NPs did not differ significantly between these morphologies. (iii) When Zn(OAc)2 was used as the zinc precursor, the synthesized ZIF-8 NPs exhibited a smaller size compared to the Zn(NO3)2-derived ZIF-8 NPs. (iv) The release rate and amount of BSA protein were higher at pH 5.0 compared to pH 7.4. (v) Among the different formulations, BSA@ZIF-8 with an M:L ratio of 1:16 at pH 5.0 was observed to have a shorter time to reach a plateau (0.5 h) and higher protein release, making it suitable for locally rapid administration in a tumor environment. BSA@ZIF-8 prepared from Zn(OAc)2 at an M:L ratio of 1:140 showed the slower release of BSA protein over a 24-h period, indicating its suitability for sustained release delivery. In conclusion, our findings provide a useful basis for the practical application of ZIF-8 NPs in protein-based drug delivery systems.

Comparison of protein quantification methods for protein encapsulation with ZIF-8 metal-organic frameworks

The use of metal-organic frameworks (MOFs) as delivery systems for biologically functional macromolecules has been explored widely in recent years due to their ability to protect their payload from a wide range of harsh conditions. Given the wide usage and diversity of potential applications, optimising the encapsulation efficiency by MOFs for different biological is of particular importance. Here, several protein quantitation methods and report were compared on the accuracy, practicality, limitations, and sensitivity of these methods to assess the encapsulation efficiency of zeolitic imidazolate frameworks (ZIF)-8 MOFs for two common biologicals commonly used in nanomedicine, bovine serum albumin (BSA), and the enzyme catalase (CAT). Using these methods, ZIF-8 encapsulation of BSA and CAT was confirmed to enrich for high molecular weight and glycosylated protein forms. However, contrary to most reports, a high degree of variance was observed across all methods assessed, with fluorometric quantitation providing the most consistent results with the lowest background and greatest dynamic range. While bicinchoninic acid (BCA) assay has showed greater detection range than the Bradford (Coomassie) assay, BCA and Bradford assays were found to be susceptible to background from the organic "MOF" linker 2-methylimidazole, reducing their overall sensitivity. Finally, while very sensitive and useful for assessing protein quality SDS-PAGE is also susceptible to confounding artifacts and background. Given the increasing use of enzyme delivery using MOFs, and the diversity of potential uses in biomedicine, identifying a rapid and efficient method of assessing biomolecule encapsulation is key to their wider acceptance.

Utilization of Functionalized Metal–Organic Framework Nanoparticle as Targeted Drug Delivery System for Cancer Therapy

Cancer is a multifaceted disease that results from the complex interaction between genetic and environmental factors. Cancer is a mortal disease with the biggest clinical, societal, and economic burden. Research on better methods of the detection, diagnosis, and treatment of cancer is crucial. Recent advancements in material science have led to the development of metal–organic frameworks, also known as MOFs. MOFs have recently been established as promising and adaptable delivery platforms and target vehicles for cancer therapy. These MOFs have been constructed in a fashion that offers them the capability of drug release that is stimuli-responsive. This feature has the potential to be exploited for cancer therapy that is externally led. This review presents an in-depth summary of the research that has been conducted to date in the field of MOF-based nanoplatforms for cancer therapeutics.

Recent advances in MOF-bio-interface: a review

Metal-organic frameworks (MOFs), as a class of promising material with adjustable function and controllable structure, have been widely used in the food industry, chemical industry, biological medicine, and sensors. Biomacromolecules and living systems play a critical role in the world. However, the insufficiency in stability, recyclability, and efficiency, significantly impedes their further utilization in slightly harsh conditions. MOF-bio-interface engineering effectively address the above-mentioned shortages of biomacromolecules and living systems, and thereby attracting considerable attentions. Herein, we systematically review the achievements in the area of MOF-bio-interface. In particular, we summarize the interface between MOFs and proteins (enzymes and non-enzymatic proteins), polysaccharides, DNA, cells, microbes, and viruses. Meanwhile, we discuss the limitations of this approach and propose future research directions. We expect that this review could provide new insights and inspire new research efforts towards life science and material science.

Fabrication of pH-sensitive magnetic metal-organic framework for controlled-release of heparin

Heparin, the most widely used anticoagulant drug in the world today, suffers from the risk of overdose and a short serum half-life, limiting its clinical applications. Concerning the controlled, sustained, and targeted release of heparin, a delivery system was fabricated in this research using the layered composites of Fe₃O₄ magnetic particles and pH-sensitive metal-organic framework, Fe₃O₄@ZIF-8. The composite demonstrated a high loading capacity for the heparin, 66.8 mg/g. The composite had a saturation magnetization of 1.5 emu/g and thus owned a magnetic targeting function, i.e. drug can be centered at a certain point using an external magnetic field. The anticoagulant activity was assessed by monitoring their activated partial thromboplastin time. The results showed that the pH-responsive and sustained release of the heparin reduced the systemic adverse effects associated with high concentrations. Moreover, control over the dose exhibited excellent anticoagulant features with fewer side effects.

Chidamide stacked in magnetic polypyrrole nano-composites counter thermotolerance and metastasis for visualized cancer photothermal therapy

Photothermal therapy (PTT) has become one of the most promising therapies in cancer treatment as its noninvasiveness, high selectivity, and favorable compliance in clinic. However, tumor thermotolerance and distal metastasis reduce its efficacy, becoming the bottleneck of applying PTT in clinic. In this study, a chidamide-loaded magnetic polypyrrole nanocomposite (CMPP) has been fabricated as a visualized cancer photothermal agent (PTA) to counter tumor thermotolerance and metastasis. The efficacy of CMPP was characterized by in vitro and in vivo assays. As a result, this kind of magnetic polypyrrole nanocomposites were black spherical nanoparticles, possessing a favorable photothermal effect and the suitable particle size of 176.97 ± 1.45 nm with a chidamide loading rate of 12.92 ± 0.45%. Besides, comparing with PTT, CMPP exhibited significantly higher cytotoxicity and cellular apoptosis rate in two tumor cell lines (B16-F10 and HepG2). In vivo study, the mice showed obvious near-infrared (NIR) and magnetic resonance imaging (MRI) dual-modal imaging at tumor sites and sentinel lymph nodes (SLNs); on the other hand, magnetic targeting guided CMPP achieved a cure level on melanoma-bearing mice through preventing metastasis and thermotolerance. Overall, with high loading efficiency of chidamide and strong magnetic targeting to tumor sites and SLNs, CMPP could significantly raise efficiency of PTT by targeting tumor thermotolerance and metastasis, and this strategy may be exploited therapeutically to upgrade PTT with MPP as one of appropriate carriers for histone deacetylase inhibitors (HDACis).

Confining Natural/Mimetic Enzyme Cascade in an Amorphous Metal-Organic Framework for the Construction of Recyclable Biomaterials with Catalytic Activity

Integrating nanozymes with natural enzymes to form cascade reactions is one of the most promising ways to develop biocatalysts with versatile performance; however, the applicability of the cascade is typically hampered by the instability of enzymes and the hindrance of mass transfer in the host environment. Utilizing amorphous ZIF-90 (aZIF-90) as a host material, herein, we have reported a one-pot way to encapsulate glucose oxidase (GOx) and magnetic nanoparticles (MNP) to form GOx/MNP@aZIF-90. We reasoned that the amorphous structure of ZIF-90 not only provides a protected environment to confine the cascade reaction but also generates mesopores and internal voids to improve the performance of the enzymatic cascade. The catalytic activity of aZIF-90 was almost 4 times higher than that of crystalline composites, and the residual activity was higher than 80% after being stored for 9 days. This is the first time that GOx and MNP were simultaneously confined in aZIF-90 with mesopores, which suggested that an amorphous metal-organic framework is promising in the development of an enzymatic cascade.

Holothurian fucosylated chondroitin sulfates and their potential benefits for human health: Structures and biological activities

Fucosylated chondroitin sulfates (FCS) are a sulfated polysaccharide exclusively existing in the body wall of sea cucumber. FCS possesses a mammalian chondroitin sulfate like backbone, namely repeating disaccharides units composed of GlcA and GalNAc, with fucosyl branches linked to GlcA and/or GalNAc residues. It is found that FCS can prevent unhealthy dietary pattern-induced metabolic syndromes, including insulin resistance and β-cell function improvement, anti-inflammation, anti-hyperlipidemia, and anti-adipogenesis. Further studies show that those activities of FCS might be achieved through positively modulating gut microbiota composition. Besides, FCS also show therapeutic efficacy in cancer, HIV infection, and side effects of cyclophosphamide. Furthermore, bioactivities of FCS are closely affected by their molecular weights, sulfation pattern of the fucosyl branches, and chain conformations. This review summarizes the recent 20 years studies to provide references for the future studies and applications of FCS in functional foods or drugs.

Facile synthesis of Zn-based metal-organic framework in the presence of carboxymethyl cellulose: A safe carrier for ibuprofen

Fabrication of porous materials with a high surface area affords a great interest to achieve a system with a prolonged drug release manner. In this context, the subject of this work is to describe a novel green one-pot synthesis route for the growth of metal-organic framework (MOF) from zinc metal (Zn) and 1, 4-benzene dicarboxylic acid (BDC) in the vicinity of the carboxymethyl cellulose (CMC), which homogeneously confined in the biopolymeric chains. The synthesized Zn (BDC)@CMC was characterized and confirmed using different analyses. N₂ adsorption/desorption isotherms determined the mean diameter of pore size of about 2.3993 nm. Ibuprofen (IBU) as a model drug was highly loaded to the Zn(BDC)@CMC by immersing in the drug solution; 50.95%. The in vitro IBU release study indicated that the Zn(BDC)@CMC has more attractive performances than pristine Zn(BDC). The IBU release occurred via the Fickian mechanism. Isotherm studies showed that the IBU adsorption on obeys from Langmuir isotherm; R² 0.9623. The MTT results revealed the HEK 293A cell viability of higher than 90% for Zn(BDC)@CMC that confirms its cytocompatibility. Overall, obtained results confirm the functionality of CMC biopolymer for in situ growth of MOF in the presence of it due to having the reactive nature.