Synthesis and Characterization of a Novel Zinc-Based Metal-Organic Framework Containing Benzoic Acid: A Low-Toxicity Carrier for Drug Delivery.

In recent years, metal-organic frameworks (MOFs) have gained attention in the biomedical field, particularly as drug carriers for treating tumors. Therefore, we decided to synthesize a novel benzoic acid Zn-based MOF and study the Zn-based MOFs' drug-delivery properties and the drug-delivery system's anticancer effects. This study successfully synthesized a zinc-based MOF using solvent thermal synthesis. The crystal structure of a Zn-based MOF was investigated using thermogravimetric analysis, X-ray diffraction, and Fourier transform infrared spectroscopy. Subsequently, the results of UV spectrophotometry showed that Doxorubicin was successfully loaded with a loading amount of 33.74%. Furthermore, the drug release experiments demonstrated that the Zn-based MOF was pH-sensitive, releasing more at a pH of 3.8 than at pH 5.8 or 7.4. Finally, the Zn-based MOF loaded with drugs exhibited high antitumor activity against HepG2 cells while demonstrating remarkably low toxicity to normal cells (LO2). Taken together, these results demonstrate that the Zn-based MOF has the potential to serve as a carrier in the field of drug delivery systems.

Reexamining the Emergence and Stability of the Square Cylinder Phase in Block Copolymers.

Recently, a few AB-type multiblock copolymers have been successfully designed to form stable square cylinder phase based on self-consistent field theory (SCFT) calculations. The previous works only identify the stability region of the square phase but not analyzing its stability, which is closely related to the free-energy landscape. In this work, we have reexamined the stability of the square phase in B 1 A 1 B 2 A 2 B 3 ${{{\rm B}}_{1}{{\rm A}}_{1}{{\rm B}}_{2}{{\rm A}}_{2}{{\rm B}}_{3}}$ linear pentablock and ( B 1 A B 2 )​ 5 ${({{\rm B}}_{1}{\rm A}{{\rm B}}_{2}{)}_{5}}$ star triblock copolymers by drawing the free-energy landscape with respect to the two dimensions of a rectangular unit cell. Our results demonstrate that the square phase continuously transfers to the rectangular phase as the degree of packing frustration is gradually released. Moreover, the prolate contour lines of the free-energy landscape indicate the weak stability of the square phase in the B 1 A 1 B 2 A 2 B 3 ${{{\rm B}}_{1}{{\rm A}}_{1}{{\rm B}}_{2}{{\rm A}}_{2}{{\rm B}}_{3}}$ copolymer. In contrast, the stability of the square phase is notably improved in the ( B 1 A B 2 )​ 5 ${({{\rm B}}_{1}{\rm A}{{\rm B}}_{2}{)}_{5}}$ copolymer due to its enhanced concentration of bridging configurations. Our work sheds light on the understanding of the stability of the square cylinder phase in block copolymers. Accordingly, we propose some possible strategies for further designing new AB-type block copolymer systems to obtain more stable square phase.

Inverse Design of Complex Block Copolymers for Exotic Self-Assembled Structures Based on Bayesian Optimization.

Variable chain topologies of multiblock copolymers provide great opportunities for the formation of numerous self-assembled nanostructures with promising potential applications. However, the consequent large parameter space poses new challenges for searching the stable parameter region of desired novel structures. In this Letter, by combining Bayesian optimization (BO), fast Fourier transform-assisted 3D convolutional neural network (FFT-3DCNN), and self-consistent field theory (SCFT), we develop a data-driven and fully automated inverse design framework to search for the desired novel structures self-assembled by ABC-type multiblock copolymers. Stable phase regions of three exotic target structures are efficiently identified in high-dimensional parameter space. Our work advances the new research paradigm of inverse design in the field of block copolymers.

Lycorine Nanoparticles Induce Apoptosis Through Mitochondrial Intrinsic Pathway and Inhibit Migration and Invasion in HepG2 Cells.

Lycorine-nanoparticles (LYC-NPs) were successfully synthesized using anti-solvent precipitation-freeze drying method, and characterized using transmission electron microscopy (TEM), particle size analysis and Fourier transform infrared spectroscopy (FTIR). Then, the antitumor effects of LYC-NPs against HepG2 cells were investigated, and the underlying molecular mechanisms were explored. Our results showed that LYC-NPs displayed potent antiproliferative against HepG2 cells concentration dependently. Flow cytometry analysis exhibited that LYC-NPs triggered apoptosis and impeded cell cycle in G0/G1 phase. Moreover, the up-regulated expression of cleaved caspases-3 and Bax, and decrease of mitochondrial membrane potential and the Bcl-2 expression were involved in LYC-NPs apoptosis, implying that LYC-NPs induced apoptosis via the mitochondrial-mediated apoptosis pathway. Furthermore, LYC-NPs distinctly impaired HepG2 cells migration and invasion with down-regulation of matrix metalloproteinase-2 (MMP-2) and MMP-9 expression. These results indicated that LYC-NPs could be an favorable agent for restraining the growth and metastasis of HepG2 cells.

Antibacterial Properties and Mechanism of Lysozyme-Modified ZnO Nanoparticles.

The lysozyme-modified nanoparticles (LY@ZnO NPs) were synthesized by the reduction-oxidation method, and the morphology and structure of LY@ZnO were analyzed by Fourier transform infrared (FTIR) spectroscopy, powder X-ray diffraction (XRD), scanning electron microsclope (SEM), and particle size analysis. The antibacterial effects of LY@ZnO against Escherichia coli (E. coli, Gram-negative bacteria) and Staphylococcus aureus (S. aureus, Gram-positive bacteria) were discussed by measuring the zone of inhibition (ZOI) and growth inhibition. The antimicrobial experiments showed that the LY@ZnO NPs possessed better antibacterial activity than ZnO. Besides, the antibacterial mechanism of LY@ZnO was also investigated, which was attributed to the generation of reactive oxygen species (ROS). Furthermore, the toxicities of LY@ZnO in vivo and in vitro were discussed by the cell counting kit-8 method and animal experiments, showing that LY@ZnO possessed excellent biocompatibility. Finally, the therapeutic effect of LY@ZnO on a rat skin infection model caused by methicillin-resistant Staphylococcus aureus (MRSA) was also studied, which exhibited good anti-infective activity. Our findings showed that LY@ZnO possessed remarkable antibacterial ability due to its excellent membrane permeability and small particle size. Besides, LY@ZnO also exhibited certain stability and great safety, which showed tremendous prospects for microbial infection in patients. It would also be helpful for a better understanding of the enzyme-modified nanomaterials against bacteria.