Background: Developing a controllable drug delivery system is imperative and important to reduce side effects and enhance the therapeutic efficacy of drugs. Metal-organic frameworks (MOFs) an emerging class of hybrid porous materials built from metal ions or clusters bridged by organic linkers have attracted increasing attention in the recent years owing to the unique physical structures possessed, and the potential for vast applications. The superior properties of MOFs, such as well-defined pore aperture, tailorable composition and structure, tunable size, versatile functionality, high agent loading, and improved biocompatibility, have made them promising candidates as drug delivery hosts. MOFs for drug delivery is of great interest and many very promising results have been found, indicating that these porous solids exhibit several advantages over existing systems. Objective: This review highlights the latest advances in the synthesis, functionalization, and applications of MOFs in drug delivery, and has classified them using drug loading strategies. Finally, challenges and future perspectives in this research area are also outlined.

This study aimed to determine whether there is an association between mammographic casting-type calcification and other prognostic factors for invasive breast cancer. We also assessed whether casting-type calcification could be an independent prognostic factor. Invasive breast cancer patient information from January 2010 and January 2013 was retrospectively reviewed. The associations between mammographic casting-type calcification and other clinicopathological factors, including tumor size, node status, grade, progesterone receptor (PR) status, estrogen receptor (ER) status, and human epidermal growth factor receptor 2 (HER2) status, were analyzed. The Kaplan–Meier method and a Cox proportional hazards model were used for survival analyses of disease-free survival (DFS) and overall survival (OS). A total of 1155 invasive breast cancer patients who underwent definitive surgery were included, and 136 cases (11.8%) had casting-type calcification on mammography. In multivariate logistic regression, casting-type calcification was significantly associated with axillary node metastasis, ER-negativity, and HER2 overexpression. Casting-type calcification significantly decreased OS and DFS after a median follow-up of 60 months. This result remained after adjusting other prognostic factors in the multivariate analysis. Casting-type calcification is significantly linked to axillary node metastasis, ER-negativity and HER2 overexpression. Casting-type calcification is therefore an independent prognostic factor for breast cancer patients.

Polar metal–organic frameworks (MOFs) have potential applications due to the fact that their organic linkers can be conveniently modified, which endows them with different properties such as non-linear optical, piezoelectric, pyroelectric, and ferroelectric performance. In the present study, an MIL-53(Cr) MOF material was prepared with a polar organic ligand including a fluorine group. In addition, a polar MOF material can be produced under continuous flow conditions with a space time yield (STY) of 7188 kg m⁻³ day⁻¹. Furthermore, a response surface methodology (RSM) was used to optimize the process conditions with the Box–Behnken design. Moreover, the piezoelectric properties of MIL-53(Cr)-F nanocrystals were probed using dual AC resonance tracking piezo-response force microscopy (PFM) and piezoresponse force spectroscopy (PFS). A PFM amplitude of 300–400 pm and a maximum amplitude of 1051 pm in a butterfly loop were observed indicating its piezoelectricity and ferroelectricity. The MIL-53(Cr)-F nanocrystals display second harmonic generation activity, indicating their polar organization. Therefore, MIL-53(Cr) with a polar linker has the potential to be used as a promising piezoelectric material, which can be produced at a large scale by continuous-flow chemistry.

Density functional theory has been used to elucidate the mechanism of Pd copolymerization of cyclopropenone with ethylene. The results reveal that introducing ethylene and cyclopropenone to Pd catalyst is thermodynamically feasible and generates the α,β-unsaturated ketone unit (UnitA). Cis-mode insertion and Path A_1a are the most favorable reaction routes for ethylene and cyclopropenone, respectively. Moreover, cyclopropenone decomposition can generate CO in situ without a catalyst or with a Pd catalyst. The Pd-catalyzed decomposition of cyclopropenone exhibits a lower reaction barrier (22.7 kcal/mol) than its direct decomposition. Our study demonstrates that incorporating CO into the Pd catalyst can generate the isolated ketone unit (UnitB). CO is formed first; thereafter, UnitB is generated. Therefore, the total energy barrier of UnitB generation, accounting for the CO barrier, is 22.7 kcal/mol, which is slightly lower than that of UnitA generation (24.0 kcal/mol). Additionally, the possibility of copolymerizing ethylene, cyclopropenone, and allyl acetate (AAc) has been investigated. The free energy and global reactivity index analyses indicate that the cyclopropenone introduction reaction is more favorable than the AAc insertion, which is consistent with the experimental results. Investigating the copolymerization mechanism will help to develop of a functionalization strategy for polyethylene polymers.

Density functional theory (DFT) was used to investigate the three-component coupling reactions of aldehydes, alkynes, and amines (A3 coupling) using N-heterocyclic carbene silver as the catalyst. This study reveals that the addition reaction between the catalyst N-heterocyclic carbene silver and phenylacetylene (PAE) forms Ag_PAE. Subsequently, one hydrogen atom of the Ag_PAE migrates to the nitrogen atom of the Amine. Thereafter, the amine aldehyde condensation reaction generates a molecule of water and an imine ion with (Path one) or without (Path two) another amine catalyst. Path one has a lower reaction barrier than Path two. Subsequently, the imine ion reacts with silver phenylacetylide to generate the A3 coupling reaction product propargylamine (PPA). Furthermore, the triple bond and −N₃ group in PPA undergo a cycloaddition reaction and generate the final product (PR). The entire reaction is strongly exothermic, and, therefore, the reaction is easy to conduct. Moreover, conceptual density functional theory calculations confirm the reaction mechanism. Investigating the mechanism of these reactions will be helpful for understanding and developing new synthesis strategies for similar functional compounds.