Novel furimazine derivatives for nanoluciferase bioluminescence with various C-6 and C-8 substituents.

Nanoluciferase (NLuc) is the emerging commercially available luciferase considering its small size and superior bioluminescence performance. Nevertheless, this bioluminescence system has some limitations, including narrow emission wavelength and single substrate. Herein, a series of novel furimazine derivatives at the C-6 and C-8 positions of the imidazopyrazinone core have been designed and synthesized for extension of the bioluminescence substrates. It should be noted that two compounds, molecules A2 (2-(furan-2-ylmethyl)-6-(4-(hydroxymethyl)phenyl)-8-(phenylthio)imidazo[1,2-a]pyrazin-3(7H)-one) and A3 (2-(furan-2-ylmethyl)-6-(4-amino-3-fluorophenyl)-8-(phenylthio)imidazo[1,2-a]pyrazin-3(7H)-one), display reasonable bioluminescence properties for in vitro and in vivo biological evaluations. In particular, compound A3 can broaden the application of NLuc bioluminescence techniques, especially for in vivo bioluminescent imaging.

Novel NanoLuc-type substrates with various C-6 substitutions.

NanoLuc (NLuc)-furimazine bioluminescence system offers several advantages over established systems, including improved stability, smaller size, and >150-fold enhancement in bioluminescence. Herein, we designed and synthesized a series of bioluminescent substrates with varying at the C-6 position of furimazine for NLuc-furimazine bioluminescence system. Among all derivatives, compounds A6 and A11 provided excellent bioluminescence characteristics compared with furimazine in vitro and in vivo. We believe that these new NLuc substrates can broaden the application of NLuc bioluminescence techniques, especially in vivo bioluminescent imaging.

Discovery of Small-Molecule Sulfonamide Fluorescent Probes for GPR120.

GPR120 is a novel target for the treatment of metabolic disease and type 2 diabetes. The small-molecule fluorescent probe could help us locate GPR120 visually and guide in-depth study of GPR120. In this study, we synthesized six nonacidic sulfonamide fluorescent probes and tested their optical and biological properties. Compared to previous probes for GPR120, these probes, with sulfonamide structure, have high selectivity on GPR120. We used these probes to establish a BRET binding assay system to screen agonists and antagonists of GPR120. It is expected that these novel fluorescent probes may become useful tools in studying pharmacology and physiology of GPR120.

Inhalable nanoparticles with enhanced cuproptosis and cGAS-STING activation for synergistic lung metastasis immunotherapy.

Due to the insufficient Cu+ accumulation, Cu+ efflux mechanism, and highly immunosuppressive tumor microenvironment (TME) in lung metastasis, the cuproptosis efficacy is limited. Herein, an inhalable nanodevice (CLDCu) is constructed to successfully overcome the drawbacks of cuproptosis. CLDCu consists of a Cu2+-chitosan shell and low molecular weight heparin-tocopherol succinate (LMWH-TOS, LT) core with disulfiram (DSF) loading. The prepared CLDCu can be inhaled and accumulate in large amounts in lung lesions (63.6%) with 56.5 times higher than intravenous injection. Within tumor cells, the mild acidity triggers the co-release of DSF and Cu2+, thus generating bis(diethyldithiocarbamate)-copper (CuET) to block Cu+ efflux protein ATP7B and forming toxic Cu+, leading to enhanced cuproptosis. Meanwhile, the released chitosan cooperates with CLDCu-induced cuproptosis to activate stimulator of interferon genes (STING) pathway, which significantly potentiates dendritic cells (DCs) maturation, as wells as evokes innate and adaptive immunity. In lung metastatic mice model, CLDCu is found to induce cuproptosis and reverse the immunosuppressive TME by inhalation administration. Moreover, CLDCu combined with anti-programmed cell death protein ligand-1 antibody (aPD-L1) provokes stronger antitumor immunity. Therefore, nanomedicine that combines cuproptosis with STING activation is a novel strategy for tumor immunotherapy.

Preparation and evaluation of inhalable S-allylmercapto-N-acetylcysteine and nintedanib co-loaded liposomes for pulmonary fibrosis.

Orally marketed products nintedanib (NDNB) and pirfenidone (PFD) for pulmonary fibrosis (PF) are administered in high doses and have been shown to have serious toxic and side effects. NDNB can cause the elevation of galectin-3, which activates the NF-κB signaling pathway and causes the inflammatory response. S-allylmercapto-N-acetylcysteine (ASSNAC) can alleviate the inflammation response by inhibiting the TLR-4/NF-κB signaling pathway. Therefore, we designed and prepared inhalable ASSNAC and NDNB co-loaded liposomes for the treatment of pulmonary fibrosis. The yellow, spheroidal co-loaded liposomes with a particle size of 98.32±1.98 nm and zeta potential of -22.5 ± 1.58 mV were produced. The aerodynamic fine particle fraction (FPF) and mass median aerodynamic diameter (MMAD) of NDNB were >50 % (81.14 %±0.22 %) and <5 µm (1.79 µm±0.06 µm) in the nebulized liposome solution, respectively. The results showed that inhalation improved the lung deposition and retention times of both drugs. DSPE-PEG 2000 in the liposome formulation enhanced the mucus permeability and reduced phagocytic efflux mediated by macrophages. ASSNAC reduced the mRNA over-expressions of TLR-4, MyD88 and NF-κB caused by NDNB, which could reduce the NDNB's side effects. The Masson's trichrome staining of lung tissues and the levels of CAT, TGF-ß1, HYP, collagen III and mRNA expressions of Collagen I, Collagen III and α-SMA in lung tissues revealed that NDNB/Lip inhalation was more beneficial to alleviate fibrosis than oral NDNB. Although the dose of NDNB/Lip was 30 times lower than that in the oral group, the inhaled NDNB/Lip group had better or comparable anti-fibrotic effects to those in the oral group. According to the expressions of Collagen I, Collagen III and α-SMA in vivo and in vitro, the combination of ASSNAC and NDNB was more effective than the single drugs for pulmonary fibrosis. Therefore, this study provided a new scheme for the treatment of pulmonary fibrosis.

Inhalable metal-organic framework-mediated cuproptosis combined with PD-L1 checkpoint blockade for lung metastasis synergistic immunotherapy.

Cuproptosis shows enormous application prospects in lung metastasis treatment. However, the glycolysis, Cu+ efflux mechanisms, and insufficient lung drug accumulation severely restrict cuproptosis efficacy. Herein, an inhalable poly (2-(N-oxide-N,N-diethylamino)ethyl methacrylate) (OPDEA)-coated copper-based metal-organic framework encapsulating pyruvate dehydrogenase kinase 1 siRNA (siPDK) is constructed for mediating cuproptosis and subsequently promoting lung metastasis immunotherapy, namely OMP. After inhalation, OMP shows highly efficient lung accumulation and long-term retention, ascribing to the OPDEA-mediated pulmonary mucosa penetration. Within tumor cells, OMP is degraded to release Cu2+ under acidic condition, which will be reduced to toxic Cu+ to induce cuproptosis under glutathione (GSH) regulation. Meanwhile, siPDK released from OMP inhibits intracellular glycolysis and adenosine-5'-triphosphate (ATP) production, then blocking the Cu+ efflux protein ATP7B, thereby rendering tumor cells more sensitive to OMP-mediated cuproptosis. Moreover, OMP-mediated cuproptosis triggers immunogenic cell death (ICD) to promote dendritic cells (DCs) maturation and CD8+ T cells infiltration. Notably, OMP-induced cuproptosis up-regulates membrane-associated programmed cell death-ligand 1 (PD-L1) expression and induces soluble PD-L1 secretion, and thus synergizes with anti-PD-L1 antibodies (aPD-L1) to reprogram immunosuppressive tumor microenvironment, finally yielding improved immunotherapy efficacy. Overall, OMP may serve as an efficient inhalable nanoplatform and afford preferable efficacy against lung metastasis through inducing cuproptosis and combining with aPD-L1.

Design, Synthesis and Preliminary Bioactivity Evaluation of N-Acetylcysteine Derivatives as Antioxidative and Anti-Inflammatory Agents.

N-acetylcysteine (NAC) is a commonly used mucolytic agent and antidote for acetaminophen overdose. For pulmonary diseases, NAC exhibits antioxidative properties, regulates cytokine production, reduces apoptosis of lung epithelial cells, and facilitates the resolution of inflammation. However, the efficacy of NAC in clinical trials targeting different pathological conditions is constrained by its short half-life and low bioavailability. In the present study, a series of NAC derivatives were designed and synthesized to further enhance its pharmacological activity. Structure-activity relationship (SAR) studies were conducted to optimize the activating groups. In vitro evaluations revealed that compounds 4 r, 4 t, 4 w, and 4 x exhibited superior antioxidative and anti-inflammatory activities compared to the positive controls of NAC and fudosteine. The ADME prediction analysis indicated that these compounds exhibited a favorable pharmacological profile. In-vivo experiments with compound 4 r demonstrated that the high-dose group (80 mg/kg) exhibited improved therapeutic effects in reversing the HPY level in mice with pulmonary fibrosis compared to the NAC group (500 mg/kg), further proving its superior oral bioavailability and therapeutic effect compared to NAC.

A cisplatin and disulphiram co-loaded inclusion complex overcomes drug resistance by inhibiting cancer cell stemness in non-small cell lung cancer.

Introduction: Non-small cell lung cancer (NSCLC) accounting for about 80-85% of all lung cancer cases is one of the fastest-growing malignancies in terms of incidence and mortality worldwide and is commonly treated with cisplatin (DDP). Although treatment may initially be effective, the DDP therapy often leads to the development of chemoresistance and treatment failure. Disulphiram (DSF), an old alcohol-aversion drug, has been revealed to help reverse drug resistance in several cancers. In addition, several studies have shown a close relationship between drug resistance and cancer cell stemness.Methods: In this study, DDP and DSF were embedded in hydroxypropyl-ß-cyclodextrin (CD) to prepare a co-loaded inclusion complex of DDP and DSF (DDP-DSF/CD) with enhanced solubility and therapeutic effects. The effects and mechanism of DSF on the DDP resistance from the perspective of cancer cell stemness were determined.Results: Our data show that DDP-DSF/CD increased cytotoxicity and apoptosis of DDP-resistant A549 (A549/DDP) cells, inhibited stem cell transcriptional regulatory genes and drug resistance-associated proteins and reversed the DDP resistance in vitro and in vivo.Discussion: Overall, DDP-DSF/CD could be a promising formulation for the reversal of DDP resistance in NSCLC by inhibiting cancer cell stemness.

S-(N,N-diethyldithiocarbamoyl)-N-acetyl-l-cysteine for the treatment of non-small cell lung cancer through regulating NF-κB signalling pathway without neurotoxicity.

The discovery of novel targeted agents for non-small cell lung cancer (NSCLC) remains an important research landscape due to the limited efficacy, side effects and drug resistance of current treatment options. Among many repurposed drugs, disulphiram (DSF) has shown the potential to target tumours. However, its unpleasant neurotoxicity greatly limits its use. A DSF derivative, S-(N,N-diethyldithiocarbamoyl)-N-acetyl-l-cysteine (DS-NAC), was synthesised against NSCLC. The therapeutic effects, mechanism and toxicities of DS-NAC were evaluated in A549 and H460 cells and the mouse model of in situ lung cancer. The in vitro results exhibited that DS-NAC had potent anti-proliferation, apoptotic, anti-metastasis and epithelial-mesenchymal transition (EMT) inhibition effects. In the orthotopic lung cancer mouse model, therapeutic effects of DS-NAC were better than those of DSF and were similar to docetaxel (DTX). Also, results from western blot and immunohistochemistry showed that DS-NAC in combination with copper exerted therapeutic effects via regulating NF-κB signalling pathway and ROS-related proteins such as HIF-1α, Nrf2 and PKC-δ rather than regulating ROS level directly. Moreover, the safety evaluation study showed that DS-NAC had low haematologic and hepatic toxicities in comparison with DTX as well as low neurological toxicity compared with DSF. DS-NAC could be a promising anti-lung cancer agent with a favourable safety profile.

Correction: Eliciting an immune hot tumor niche with biomimetic drug-based multi-functional nanohybrids augments immune checkpoint blockade-based breast cancer therapy.

Correction for 'Eliciting an immune hot tumor niche with biomimetic drug-based multi-functional nanohybrids augments immune checkpoint blockade-based breast cancer therapy' by Wei Du et al., Nanoscale, 2020, 12, 3317-3329, https://doi.org/10.1039/C9NR09835F.

Eliciting an immune hot tumor niche with biomimetic drug-based multi-functional nanohybrids augments immune checkpoint blockade-based breast cancer therapy.

Immune checkpoint blockade (ICB) has emerged as one of the breakthrough approaches for tumor immunotherapy. However, known as an immune "cold" tumor, breast cancer harbors an immunosuppressive tumor niche that compromises ICB-based therapy. Chemoimmunotherapy combines a chemotherapeutic with an immune-modulating agent, representing a promising tactic to combat cancers, while the lack of effectively targeted co-delivery strategy is one of the main obstacles to achieve the synergistic utilization. Herein, self-assembled PEGylated pure drug-based nanohybrids (DNH) were created, which could evoke immunogenic cell death (ICD), aiding ICB-based immunotherapy by controlling the spatiotemporal release of oxaliplatin (OXA) and small molecular inhibitor 1-methyl-d-tryptophan (1-MT). Furthermore, biomimetic functionalization was exploited by nature killer cell membrane camouflaging to target cancerous cells as well as by elicit immune response through inducing M1 macrophage polarization. The drug release profiles of the nanosystem were investigated in the presence of low pH and intracellular reductants. Systemic in vivo bio-behaviors were evaluated via pharmacokinetics and biodistribution. As an "all-in-one" pure drug-based codelivery system, our biomimetic nanoplatform possessed multiple immunomodulation functions, which markedly aided in increasing the frequency of immune responders and generate an immune "hot" breast tumor niche, and eventually allowed to boost breast cancer therapy.