Advancements and Challenges in the Application of Metal-Organic Framework (MOF) Nanocomposites for Tumor Diagnosis and Treatment.

Nanoscale metal-organic frameworks (MOFs) offer high biocompatibility, nanomaterial permeability, substantial specific surface area, and well-defined pores. These properties make MOFs valuable in biomedical applications, including biological targeting and drug delivery. They also play a critical role in tumor diagnosis and treatment, including tumor cell targeting, identification, imaging, and therapeutic methods such as drug delivery, photothermal effects, photodynamic therapy, and immunogenic cell death. The diversity of MOFs with different metal centers, organics, and surface modifications underscores their multifaceted contributions to tumor research and treatment. This review is a summary of these roles and mechanisms. The final section of this review summarizes the current state of the field and discusses prospects that may bring MOFs closer to pharmaceutical applications.

Potential Biomedical Limitations of Graphene Nanomaterials.

Graphene-family nanomaterials (GFNs) possess mechanical stiffness, optical properties, and biocompatibility making them promising materials for biomedical applications. However, to realize the potential of graphene in biomedicine, it must overcome several challenges that arise when it enters the body's circulatory system. Current research focuses on the development of tumor-targeting devices using graphene, but GFNs accumulated in different tissues and cells through different pathways, which can cause toxic reactions leading to cell apoptosis and body dysfunction when the accumulated amount exceeds a certain limit. In addition, as a foreign substance, graphene can induce complex inflammatory reactions with immune cells and inflammatory factors, potentially enhancing or impairing the body's immune function. This review discusses the biomedical applications of graphene, the effects of graphene materials on human immune function, and the biotoxicity of graphene materials.

Effects of Metal Ions on Conductivity and Structure of Single DNA Molecule in Different Environmental Conditions.

We design a novel nano-gap electrode to measure the current of DNA molecule, by which the current-voltage characteristics of individual native DNA, Ag-DNA and Ni-DNA molecules are obtained, respectively. The results show that the voltage gap of Ag- and Ni-DNA is higher than that of native DNA, and the conductance is lower than native DNA in neutral environment. The structure transition from B- to Z-DNA is observed in the presence of high concentrations of nickel ions and Ag-DNA appears chaos state by STM image and U-V spectra characterization. But in alkaline environment, the conductance of Ni-DNA rises and the voltage gap decreases with the increasing of nickel ion concentration denotes that the conductive ability of Ni-DNA is higher than that of native DNA.

[SERS spectra of serum from rash].

The SERS spectra of serums from the healthy persons and rash patients were measured. In the serum of rash, the band of amide I appeared at 1648 cm(-1), while this peak vanished in healthy serums. The relative intensity of 637 cm(-1) assigned to the gauche conformation of C S increased 23% and the band at 725 cm(-1) corresponding to anti-conformation decreases 60%. These indicate that the structure of the protein has changed in serums from the rash patients. The relative intensity at 1449 cm(-1) assigned to the lipids increased nearly one time. The band at 1099 cm(-1) assigned to the Man-D vanished, indicating that the contents of lipids, glucide and protein increased in rash patients. These results may offer a powerful experiment basis for rash diagnosis and biochemistry mechanism study. The multivariae ura statistical methods of principal component analysis (PCA) were also used to analyze the SERS of the serums from healthy persons and rash patients, it can be seen that the regional distribution of rash is wider than healthy volunteers, showing that these serums can be discriminated by PCA.

[SERS spectra of serum from diabetic].

The SERS spectra were measured from normal and the diabetic serum. In the diabetic serum, the band of amide II shifted to 1 585 cm(-1) and the relative intensity increased 14%, while the relative intensity of 593 cm(-1) which belongs to amide VI reduced 33%. For the protein side chain, the band at 1 368 cm(-1) assigned to the "buried" tryptophan shifted to 1 365 cm(-1) of the "exposed" and the relative intensity reduced 59%. The relative intensity of 635 cm(-1) assigned to the gauche conformation of the C-S decrased 15% and the band at 725 cm(-1) increased 58%. These indicate that the structure of the protein changed in the diabetic serum. The relative intensity at 1 449 cm(-1) assigned to the lipids characteristic increased 58%. The relative intensity of the glucide characteristic at 1 331, 1 099 and 740 cm(-1) increased 35%, 100% and 62%, respectively. So it is indicated that the content of lipids, glucide and protein increased in diabetic. These results may offer a powerful experimental basis for diabetes diagnosis and biochemistry mechanism study.

[Preparation of DNA silver nanowire and its Raman spectra].

Silver nanoparticles were synthesized by the method of combining heating with UV irradiation. In the authors' work, the shape and size of nanograins which carry positive electrical charges are uniform and their average diameter is 7.8 nm. Based on the electrostatic self-assembly characteristics of DNA, silver nanoparticles were equally assembled on predefined aligned calf thymus DNA to form DNA silver nanowires. The diameter of the wires is about 30 nm and the length is 2 microm. The Raman spectra indicate that the silver nanoparticles mainly attach to the backbone chain of DNA and affect the vibration properties of deoxyribose and base. The intensity of the peaks at 782 and 1 098 cm(-1) assigned to stretch vibration of phosphoric skeleton decreases sharply and the band at 782 cm(-1) shifts to 791 cm(-1). The bands of deoxyribose C-O stretch vibration at 1 011 and 1 050 cm(-1) shift to 1 030 and 1 064 cm(-1) respectively. The characteristic peaks of bases at 1 372, 1 334, 1 304 and 728 cm(-1) shift to 1 368, 1 320, 1 294 and 731 cm(-1), respectively.

Study on the Electric Conductivity of Ag-Doped DNA in Transverse Direction.

In this article, we reported a novel experiment results on Ag-doped DNA conductor in transverse direction. I-V characteristics were measured and the relative conductances were calculated for different silver ions concentrations. With the increase of the concentration of silver ions, the conductive ability of DNA risen rapidly, the relative conductance of DNA enhanced about three magnitudes and reached a stable value when Ag(+) concentration was up to 0.005 mM. In addition, Raman spectra were carried out to analyse and confirm conduction mechanism.