Latest ArticlesPost-synthetic modifications (PSM) have drawn great attention as a vigoroso tool to tune or enhance the performance of metal-organic frameworks (MOFs). However, the current PSM method usually have to sacrifice the porosity of MOFs to enrich their functionality, such as pore space partition (PSP) and post-synthetic elimination and insertion (PSE&I), causing a trade-off in this aspect. To address this issue, we herein propose a new PSM strategy of using the size-matching ligands as the bolts to lock MOFs’ pores, which could be anchored onto open metal sites (OMSs) after guest loading through a stepwise manipulation. As a result, the loaded cargoes undergo a controlled releasing process with respect to different bolt ligands. Our proposed strategy provides a promising way to balance the functionality and porosity of MOFs.
For a significant duration, enhancing the efficacy of cancer therapy has remained a critical concern. Magnetotactic bacteria (MTB), often likened to micro-robots, hold substantial promise as a drug delivery system. MTB, classified as anaerobic, aquatic, and gram-negative microorganisms, exhibit remarkable motility and precise control over their internal biomineralization processes. This unique ability results in the formation of magnetic nanoparticles arranged along filamentous structures in a catenary fashion, enclosed within a membrane. These bacteria possess distinctive biochemical properties that facilitate their precise positioning within complex environments. By harnessing these biochemical attributes, MTB could potentially offer substantial advantages in the realm of cancer therapy. This article reviews the drug delivery capabilities of MTB in tumor treatment and explores various applications based on their inherent properties. The objective is to provide a comprehensive understanding of MTB-driven drug delivery and stimulate innovative insights in this field.
Polyketide synthases (PKSs) are megasynthases with multiple autonomously folding domains, which operate cooperatively in the PKS assemblies to synthesize specific polyketide scaffolds. Any nonreactive intermediates tethered to acyl carrier protein (ACP) domain in the PKS will block the elongation process of polyketide chains. In this study, we systematically elucidate the editing function of fungal type Ⅱ thioesterases (TEIIs) to hydrolyze ACP domain-bounded nonreactive acyl groups, which are uploaded by substrate promiscuous fungal phosphopantetheinyl transferase. Thereof, the TEIIs encoded in gene clusters of nonreducing PKS with reductase domain exhibit universal editing function. Besides, editing function was also found for TEIIs encoded in gene clusters of highly-reducing PKS with condensation domain. Hence, the editing TEIIs with function of recovery PKS are applied to improve the yield of the fungal polyketides in vivo. Our study provides valuable insights into the editing process of fungal PKSs, highlights the crucial role of TEIIs in enhancing polyketide production and introduces a novel metabolic engineering strategy for fungal polyketide biosynthesis by leveraging the editing function of TEIIs.
Since the appearance of Rochelle salt, ferroelectrics have received extensive attention from researchers due to they are playing an important role in sensors, memories, mechanical actuation, and so on. In recent years, with the rapid development of molecular ferroelectrics, high-performance molecular ferroelectrics have become effective complement to inorganic ferroelectrics. However, compared with inorganic ferroelectrics, the family of molecular ferroelectrics is relatively scarce, and exploring high-performance ferroelectric materials through new synthesis strategies has become the trend of molecular ferroelectrics. Here, we successfully transformed non-polar material 1 (2-H2PCA)2(H2O)CdCl6 (2-H2PCA = 2-picolylamine cation) into polar material 2 (2-H2PCA)2CdCl6 by single-crystal to single-crystal transformation (SCSCT). Meanwhile, 2 exhibits clear ferroelectricity with a high-temperature Tc of 378 K, a Ps of 1.18 µC/cm2 at 300 K. This work not only realizes the purpose of synthesizing ferroelectrics by forming polar structures by SCSCT, but also realizes the reversibility of SCSCT, which provides ideas for the construction and exploration of new molecular ferroelectrics.
Clinical phototheranostic agents suffer from low absorption in near-infrared (NIR) region, decreasing singlet oxygen quantum yield (1O2 QY) caused by aggregation in water, and low photothermal conversion efficiency (PCE), all of which are factors weakening their phototheranostic efficacy. Herein, we designed and synthesized a donor-acceptor-donor (D-A-D) structured boron-dipyrromethene derivative (B-2TPA) which exhibited NIR absorption and fluorescence. After being encapsulated in amphiphilic distearoyl phosphoethanolamine polyethyleneglycol 2000 (DSPE-PEG-2000), the water-soluble B-2TPA nanoparticles (NPs) had increasing 1O2 QY (6.7%) due to the intermolecular aggregation-induced decrease in the energy gap between singlet and triplet excited states. Moreover, the quenched fluorescence and stable twisted intramolecular charge transfer in aggregates further increased the PCE of B-2TPA NPs to 60.1%. In vitro and in vivo studies confirmed that B-2TPA NPs could be used in NIR fluorescence and photoacoustic imaging-guided synergistic photodynamic and photothermal therapy in tumor treatment.
Solar-driven H2O2 production and emerging organic pollutants (EOPs) elimination are of great significance from the perspective of environmental sustainability. The efficiency of the photocatalytic reaction system is the key challenge to be addressed. In this work, the strategy of constructing surface ionic local polarization centers to enhance the exciton dissociation of the polymeric photocatalytic is demonstrated. Selected bipyridinium cation (TMAP) is complexed on a K+-incorporated carbon nitride (CNK) framework, and the combination of local polarization centers both on the surface (bipyridinium cation) and bulk (K+ cation) contributes to a superior photocatalytic H2O2 production performance, affording a remarkable H2O2 generation rate of 46.8 µmol h−1 mg−1 and a high apparent quantum yield (AQY) value of 77.5% under irradiation of 405 nm photons. As substantiated experimentally by steady state/transient spectroscopy techniques, the surface local polarization centers increase the population of the long-lived trapped electrons, and thereby promote the interfacial charge transfer process for chemical conversion reaction. The strategy is potentially applicable to the design of a wide range of efficient solar-to-chemical conversion systems.
The development of resistance against most of the available antibiotics has made Acinetobacter baumannii (A. baumannii) a pathogen of high risk. In this study, thirty novel berberine derivatives are rationally designed, synthesized, and evaluated for their synergistic antibacterial activities against A. baumannii. Among them, compound 2d shows the most potent synergetic effect to aztreonam against A. baumannii, including carbapenem-resistant and extended-spectrum β-lactamases-producing strains. Moreover, synergistic effects were observed for the combinations of 2d and different antibacterial used in clinical practices, indicating its potent broad-spectrum antibiotic-sensitizing effects against A. baumannii. The combination of 2d and aztreonam significantly improves the survival rates of G. mellonella larvae compared with aztreonam treatment alone. Mechanism studies indicate that 2d inhibits the drug efflux and iron acquisition of the bacteria by targeting the AdeB transporter protein, thus achieving a synergistic antimicrobial efficacy with different antibacterial agents. Therefore, berberine derivatives represent a new family of antimicrobial adjuvants against A. baumannii, with the advantage of dual-function antibacterial effect, and are worthy of further investigation.
Photodynamic therapy (PDT) has garnered significant attention as a promising approach to cancer therapy, harnessing the combined benefits of localized light treatment and the accompanying host immune response. In this study, we engineered an immuno-enhanced PDT nanoplatform, denoted as HM@p-MOF (hybrid membrane@porphyrin-metal organic framework). The core porphyrin-MOF was cloaked with a hybrid membrane derived from B16F10 cancer cells and NK cells, resulting in enhanced stability. In both in vitro and in vivo experiments, our finding demonstrated that the hybrid membrane conferred dual targeting capabilities to the nanoplatform, leveraging the unique properties of the B16F10 membrane and NK membrane to augment immunogenic cell death (ICD) induced by photodynamic effects. Additionally, in conjunction with the immunomodulatory functions of the NK cell membrane, we observed an expansion of in situ immune infiltration leading to a systemic immune response. The HM@p-MOF nanoplatform exhibited the capacity to not only inhibit the growth of mouse melanoma but also suppress metastasis. This innovative HM@p-MOF nanoplatform present a viable strategy to enhance phototherapeutic efficacy for both localized and metastatic tumors. It provides a direction for the fabrication of biomimetic nanomedicines possessing immuno-modulatory function.
The occurrence of acquired resistance to cisplatin (DDP) that induces the toxic drug effects has always been a huge challenge and urgently needs to be resolved in the cancer treatment. The combination of anticancer drugs with different mechanisms can remarkably improve the chemotherapeutic efficiency. Given that glutathione (GSH) plays as the driving factors in the resistance of DDP, here we have firstly proposed a “three birds, one stone” based nanoplatform to achieve triple synergetic effects simultaneously addressing DDP resistance in non-small cell lung cancer (NSCLC). Specifically, we initially designed and synthesized a DDP prodrug [Pt(Ⅳ)] bridged silsesquioxane precursor (Pt-Si). Then Pt-Si and bis[3-(triethoxysilyl)propyl]diselenide (BTESePD) were integrated into the framework of mesoporous organosilica nanoparticles (MONs) to obtain a nanocarrier MONPt/Se. After loading with norcantharidin (NCTD) and modifying with the aptamer AS1411 based G-quadruplex (Apt), the Apt@NCTD@MONPt/Se exhibit impressive tumor homing capability. Once being endocytosed, (Ⅰ) the diselenide and -O-Pt(Ⅳ)-O- rich scaffold can be reduced by the excessive GSH, followed by (Ⅱ) breaking the redox homeostasis via GSH depletion and precise release of the DDP. Next, the encapsulated NCTD is also released along with the degradation of the nanocarriers thereby (Ⅲ) achieving the GSH depletion and synergistic anti-tumor effect of NCTD and DDP. Taken together, we believe this “one stone, three birds” strategy may be a promising paradigm to conquer drug resistance for clinical care.