Nucleolus imaging based on naphthalimide derivatives.

Nucleolus was an important cellular organelle. The abnormal morphology and number of the nucleolus have been considered as diagnostic biomarkers for some human diseases. However, the imaging agent based on nucleolus was limited. In this manuscript, a series of nucleolar fluorescent probes based on naphthalimide derivatives (NI-1 âˆ¼ NI-5) had been designed and synthesized. NI-1 âˆ¼ NI-5 could penetrate cell membranes and nuclear membranes, achieve clear nucleolar staining in living cells. These results suggested that the presence of amino groups on the side chains of naphthalimide backbone could enhance the targeting to the cell nucleolus. In addition, the molecular docking results showed that NI-1 âˆ¼ NI-5 formed hydrogen bonds and hydrophobic interactions with RNA, and exhibited enhanced fluorescence upon binding with RNA. These results will provide favorable support for the diagnosis and treatment of nucleolus-related diseases in the future.

Fluorescence sensing and glycosidase inhibition effect of multivalent glycosidase inhibitors based on Naphthalimide-deoxynojirimycin conjugates.

Synthetic glycoconjugates as chemical probes have been widely developed for the detection of glycosidase enzymes. However, the binding interactions between iminosugar derivatives and glycosidases were limited, especially for the binding interactions between multivalent glycosidase inhibitors and α-glycosidases. In this paper, three naphthalimide-DNJ conjugates were synthesized. Furthermore, the binding interactions and glycosidase inhibition effects of them were investigated. It was found that the strong binding interactions of multivalent glycosidase inhibitors with enzymes were related to the efficient inhibitory activity against glycosidase. Moreover, the lengths of the chain between DNJ moieties and the triazole ring for the naphthalimide-DNJ conjugates influenced the self-assembly properties, binding interactions and glycosidase inhibition activities with multisource glycosidases. Compound 13 with six carbons between the DNJ moiety and triazole ring showed the stronger binding interactions and better glycosidase inhibition activities against α-mannosidase (jack bean) and α-glucosidase (aspergillus niger). In addition, compound 13 showed an effective PBG inhibition effect in mice with 51.18 % decrease in blood glucose at 30 min. This result opens a way for detection of multivalent glycosidase inhibition effect by a fluorescent sensing method.

Universal colorful staining of cancer tissues and normal tissues for histological diagnosis.

The versatility of multicolor imaging of human tissues based on staining with perylene monoimide-mannose conjugates PMI-Man and co-staining with PMI-Man and eosin (P&E) was investigated for human cancer and normal tissues. Staining with PMI-Man or co-staining with PMI-Man and eosin showed a perfect histological morphology both in confocal fluorescence microscopy and light microscopy. This approach provided a universal colorful staining method for cancer tissues and normal tissues.

Nucleus-targeting imaging and enhanced cytotoxicity based on naphthalimide derivatives.

Organelles possess critical biological effects in cellular processes. However, the relationship between organelle targeting and antitumour activity is a challenging issue. In this paper, a number of amide/acylhydrazine modified naphthalimide derivatives were designed and synthesized. Interestingly, amide modified naphthalimide derivatives NI-A-NH and NI-C-NH with (R)-piperdine and (S)-pyrrolidine functionalization exhibited enhanced cytotoxicity compared with acylhydrazine modified derivatives NI-A-2NH and NI-C-2NH. However, acylhydrazine modified derivatives NI-B-2NH and NI-D-2NH with (S)-piperdine and achiral piperdine conjugates possessed better cytotoxicity than NI-B-NH and NI-D-NH with amide modifications. Fluorescence imaging, DNA binding interactions and cell cycle analyses were further completed to clarify that the nucleus-targeting effects showed enhanced cytotoxic activity, strong DNA binding and the blocking of cells in S phase. These results provide a preliminary theoretical basis for the further design of organelle-targeting antitumour drugs.

Lysosomes-targeting imaging and anticancer properties of novel bis-naphthalimide derivatives.

A series of novel N,N-bis(3-aminopropyl)methylamine bridged bis-naphthalimide derivatives NI1-NI8 containing saturated nitrogenous heterocycles were designed and synthesized, their cytotoxic activities against Hela, MCF-7, A549 and MGC-803 cells were investigated, Compounds NI1-NI4 modified with piperidine and piperazine exhibited good and selective cytotoxic activity, for instance, compounds NI1 and NI4 showed potent cytotoxic activity against Hela cells and MGC-803 cells with the IC50 values of 2.89, 060, 2.73 and 1.60 µM, respectively, better than the control drug (Amonafide). However, compounds NI5-NI8 conjugated with pyrrole derivatives showed weak cytotoxic activities against the all tested cell lines. Furthermore, their DNA binding properties, fluorescence imaging and cell cycle were investigated. Interestingly, compounds NI1 and NI4 showed fluorescence enhancement because of the strong binding with Ct-DNA, and exhibited fluorescence imaging with Hela cells on the lysosomes.

Supramolecular nanofiber of pyrene-lactose conjugates and its two-photon fluorescence imaging.

A lactose modified pyrene derivative (Py-Lac) was synthesized, with which novel twisted supramolecular nanofibers in diameter about 20 nm were constructed by self-assembly. The nanofibers showed solid-state fluorescence between 400 nm and 650 nm with the maximum emission at 495 nm. Furthermore, its recognition reaction with PNA lectin was investigated by fluorescence spectra and turbidity assays. It is interesting found that the supramolecular assembly as multivalent glycocluster exhibited unique and selectively binding interactions with PNA lectin with the binding constant of 5.74 × 106 M-1. Moreover, compound Py-Lac showed two-photon fluorescence imaging with Hep G2 cells.

High excimer-state emission of perylene bisimides and recognition of latent fingerprints.

High excimer-state emission in the H-type aggregate of a novel asymmetric perylene bisimide derivative, 6, with triethyleneglycol chains and lactose functionalization was achieved in water. Furthermore, its application for enhancing the visualization of transfer latent fingerprints from glass slides to the poly(vinylidene fluoride) (PVDF) membrane was explored, which showed clear images of the latent fingerprint in daylight and under 365 nm ultraviolet illumination.

Synthesis of biocompatible glycodendrimer based on fluorescent perylene bisimides and its bioimaging.

A novel water-soluble fluorescent glycodendrimer based on perylene bisimides is synthesized, which exhibits high fluorescence quantum yield of 54%. While the binding interactions of PBI-Man with Concanavalin A (Con A) are studied by fluorescence spectra and CD spectra, which show strong binding affinity for Con A with the binding constant of 3.8 × 10(7) m(-1) for monomeric mannose, nearly four orders of magnitude higher affinity than the monovalent mannose ligand. Furthermore, the fluorescence imaging of macrophage cell with PBI-Man is investigated, and shows selectively binding interaction with the mannose receptor-medicated cell entry. Moreover, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) activities of PBI-Man show that PBI-Man as a biocompatible agent is noncytotoxic to living cells.

Amphiphilic α-Peptoid-deoxynojirimycin Conjugate-based Multivalent Glycosidase Inhibitor for Hypoglycemic Effect and Fluorescence Imaging.

Multivalent glycosidase inhibitors based on 1-deoxynojirimycin derivatives against α-glucosidases have been rapidly developed. Nonetheless, the mechanism based on self-assembled multivalent glucosidase inhibitors in living systems needs to be further studied. It remains to be determined whether the self-assembly possesses sufficient stability to endure transit through the small intestine and subsequently bind to the glycosidases located therein. In this paper, two amphiphilic compounds, 1-deoxynojirimycin and α-peptoid conjugates (LP-4DNJ-3C and LP-4DNJ-6C), were designed. Their self-assembling behaviors, multivalent α-glucosidase inhibition effect, and fluorescence imaging on living organs were studied. LP-4DNJ-6C exhibited better multivalent α-glucosidase inhibition activities in vitro. Moreover, the self-assembly of LP-4DNJ-6C could effectively form a complex with Nile red. The complex showed fluorescence quenching effect upon binding with α-glucosidases and exhibited potent fluorescence imaging in the small intestine. This result suggests that a multivalent hypoglycemic effect achieved through self-assembly in the intestine is a viable approach, enabling the rational design of multivalent hypoglycemic drugs.

Alleviating Recombinant Tissue Plasminogen Activator-induced Hemorrhagic Transformation in Ischemic Stroke via Targeted Delivery of a Ferroptosis Inhibitor.

Intravenous thrombolysis with recombinant tissue plasminogen activator (rtPA) is the primary treatment for ischemic stroke. However, rtPA treatment can substantially increase blood-brain barrier (BBB) permeability and susceptibility to hemorrhagic transformation. Herein, the mechanism underlying the side effects of rtPA treatment is investigated and demonstrated that ferroptosis plays an important role. The ferroptosis inhibitor, liproxstatin-1 (Lip) is proposed to alleviate the side effects. A well-designed macrocyclic carrier, glucose-modified azocalix[4]arene (GluAC4A), is prepared to deliver Lip to the ischemic site. GluAC4A bound tightly to Lip and markedly improved its solubility. Glucose, modified at the upper rim of GluAC4A, imparts BBB targeting to the drug delivery system owing to the presence of glucose transporter 1 on the BBB surface. The responsiveness of GluAC4A to hypoxia due to the presence of azo groups enabled the targeted release of Lip at the ischemic site. GluAC4A successfully improved drug accumulation in the brain, and Lip@GluAC4A significantly reduced ferroptosis, BBB leakage, and neurological deficits induced by rtPA in vivo. These findings deepen the understanding of the side effects of rtPA treatment and provide a novel strategy for their effective mitigation, which is of great significance for the treatment and prognosis of patients with ischemic stroke.

A triazatruxene-based glycocluster as a fluorescent sensor for concanavalin A.

A new triazatruxene-based fluorescent glycocluster has been designed, synthesized, and fully characterized by NMR spectroscopy and mass spectrometry. Furthermore, its specific and selective binding properties with concanavalin A (Con A) have been investigated by fluorescence spectroscopy, circular dichroism (CD) spectroscopy, and turbidity assay. The obtained results showed that the multivalent mannose-modified triazatruxene exhibited specific binding with Con A, but no binding to peanut agglutinin (PNA) lectin or bovine serum albumin (BSA), corresponding to a two-orders-of-magnitude higher affinity than that of monovalent mannose ligands. Most interestingly, a fluorescence enhancement of the triazatruxene-based glycocluster was observed upon binding with Con A because of hydrophobic interactions involving sites close to the triazatruxene moiety. Furthermore, the inhibitory ability of the triazatruxene-based glycocluster against ORN178-induced haemagglutination has been investigated by haemagglutination inhibition assay. The results indicated selective binding with ORN178.

Synthesis of perylene bisimide-centered glycodendrimer and its interactions with concanavalin A.

A novel glycodendrimer based on 18 peripheral α-D-mannoses functionalized perylene bisimide derivative PBI-18-Man was synthesized and its selectively binding interactions for Con A were investigated by CD spectra and turbidity assay, which exhibited strong binding affinity for Con A with the binding constant of 1.3×10(8) M(-1) (7.2×10(6) M(-1) for monomeric mannose, valency corrected), 3 orders of magnitude higher affinity than the monovalent mannose ligand. Furthermore, the inhibitory activity for Con A was studied by ELLA experiment, showed 2 times inhibitor activity than the reference compound (α-MMP).

Multivalent glycoclusters constructed by chiral self-assembly of mannose functionalized perylene bisimide.

Water-soluble perylene bisimide derivative 7 modified with six mannoses was synthesized and its self-assembled properties were studied by UV-Vis and CD spectroscopy, which revealed an interesting self-assembly with a solvent-tuning chiral conformation in H(2)O-DMSO solution. As H(2)O was added to the DMSO solution until a 60% (or 70%) v/v proportion was achieved, the self-assembly of the mannose functionalized compound 7 exhibited a left-handed helical conformation. More interestingly, when the volume of H(2)O constituted beyond 85% of the solution, the conformation of the self-assembly turned out to be a right-handed helical conformation. Furthermore, the binding interactions between the self-assembly of compound 7 and Con A were investigated by turbidity assay, CD spectra, TEM and SEM images, and ELLA experiment, which indicated that the self-assembly of compound 7 as multivalent glycoclusters exhibited specific binding to Con A with an IC(50) value of 24 µM (144 µM, valency corrected), 10 times stronger than the reference compound (α-MMP).

Calixarene-based cryoprotectants for ice recrystallization inhibition and cell cryopreservation.

The development of new cryoprotectants for cryopreservation of cells has attracted considerable interest. Herein, five calixarene-based CPAs (SC4A, S-S-C4A, S-SO2-C4A, SBAC4A, and CAC4A) were developed, and their IRI activity, DIS property and cryoprotective effect were studied. SBAC4A with a sulphobetaine zwitterion and SC4A with sulfo group modification possessed better cryoprotective effects than the other calixarene-based CPAs, especially for SBAC4A with the enhanced cell viabilities of 16.16 ± 1.78%, 12.60 ± 1.15% and 14.90 ± 1.66% against MCF-7, hucMSCs and A549 cells, respectively. This result provides a supramolecular principle for developing novel CPAs with consideration of the factors of hydrogen bonding, the macromolecular crowding principle and the three-dimensional (3D) structure.

Triple targeting host-guest drug delivery system based on lactose-modified azocalix[4]arene for tumor ablation.

Host-guest drug delivery systems (HGDDSs) have been studied in an effort to modify the characteristics of therapeutic agents through noncovalent interactions, reduce toxic side effects and improve therapeutic effects. However, it is still an important task to continuously improve the targeting ability of HGDDSs, which is conducive to the development of precision medicine. Herein, we utilize the lactose-modified azocalix[4]arene (LacAC4A) as a triple targeting drug carrier customized for antitumor purposes. LacAC4A integrates three targeting features, passive targeting through the enhancing permeability and retention effect, active targeting by the interactions of lactose and the asialoglycoprotein receptors on the surface of tumor cells, and stimuli-responsive targeting via the reduction of the azo group under a hypoxia microenvironment. After loading doxorubicin (DOX) in LacAC4A, the supramolecular nanoformulation DOX@LacAC4A clearly showed the effective suppression of tumor growth through in vivo experiments. LacAC4A can achieve effective targeting, rapid release, and improve drug bioavailability. This design principle will provide a new material for drug delivery systems.

Supramolecular Integration of Multifunctional Nanomaterial by Mannose-Decorated Azocalixarene with Ginsenoside Rb1 for Synergistic Therapy of Rheumatoid Arthritis.

The complexity and progressive nature of diseases require the exploitation of multifunctional materials. However, introducing a function inevitably increases the complexity of materials, which complicates preparation and decreases reproducibility. Herein, we report a supramolecular integration of multifunctional nanomaterials based on mannose-modified azocalix[4]arene (ManAC4A) and ginsenoside Rb1 (Rb1), which showed advances of simplicity and reproducibility. ManAC4A possesses reactive oxygen species (ROS) scavenging capacity and hypoxia-responsiveness, together with macrophage-targeting and induction functionality. Collectively, the Rb1@ManAC4A assembly simply prepared by two components is integrated with multifunction, including triple targeting (ELVIS targeting, macrophage-targeting, and hypoxia-targeted release) and triple therapy (ROS scavenging, macrophage polarization, and the anti-inflammatory effect of Rb1). The spontaneous assembly and recognition of ManAC4A, with its precise structure and molecular weight, facilitated the simple and straightforward preparation of Rb1@ManAC4A, leading to excellent batch consistency. Progress in simplicity and reproducibility, as directed by this research, will catalyze the clinical translation of multifunctional materials.

Synthesis, Renal Clearance, and Photothermal Therapy Based on the Self-Assembly of a Nanomedicine Consisting of Quaterrylene Bisimide and Glycocluster Conjugates.

Renal-clearable nanomedicines are considered the next generation of nanomedicines, and show potential application for future clinical translations. However, it is important to determine whether self-assembly can form large aggregates that accrue in tumors and then tailor the size of these assemblies to be excreted renally. In this paper, a renal-clearable nanomedicine based on quanterrylene bisimide-mannose conjugates (QDI-Man) was developed. QDI-Man showed a high renal clearance efficiency of 80.31 ± 2.85% in mice. We confirmed that the self-assembly of QDI-Man exhibited a dynamic adjustment process through the renal filtration thresholds, that is, "aggregation → self-regulating the aggregate size through the renal filtration thresholds → reaggregating into aggregates". Benefiting from the modification of mannose-based glycoclusters, QDI-Man showed selective photothermal therapy because of the mannose receptors overexpressed in breast cancer cells, and showed good photothermal therapy in mice. This paper developed a dynamic adjustment theory for effective renal clearance based on organic self-assembly.

Macrocycle molecule-based cryoprotectants for ice recrystallization inhibition and cell cryopreservation.

Cyclodextrin-based cryoprotectants were developed. α-TMCD, which can be easily put into large-scale production, showed enhanced cell viabilities of 19.97 ± 0.78%, 13.93 ± 4.46% and 19.10 ± 0.95% against GES-1, hucMSCs and A549 cells. Moreover, the viable cells observed by light microscope imaging showed that the enhanced hucMSC cell number percentage of α-TMCD was 103.2%. An α-TMCD-DMSO-based CPA exhibited an enhanced cryoprotective effect by a mechanism of DMSO-enhanced cell penetrating effect and α-TMCD-DMSO synergistically enhanced IMA ability. α-TMCD exhibited potential for the discovery of macrocycle-molecule-based cryoprotectants.

Multivalent glucosidase inhibitors based on perylene bisimide and iminosugar conjugates.

Although multivalent glucosidase inhibitors based on iminosugars have shown enhanced inhibition activity, an effective way to improve their hypoglycemic effect in vivo, is still in infancy and needs further development. In this paper, PBI-5DNJ and PBI-6DNJ, with three or four DNJ moieties respectively conjugated at the bay position were synthesized. PBI-6DNJ evidenced stronger π-π stacking interactions and, when self-assembled, a smaller size than that of PBI-5DNJ. It was found that PBI-6DNJ exhibited superior α-glucosidases (from mice) inhibition activity (Ki = 0.14 ± 0.007 µM) in vitro than that (Ki = 0.31 ± 0.01) of PBI-5DNJ and in vivo hypoglycemic effects in mice models. PBI-6DNJ possessed good hypoglycemic effects with the percentages of PBG levels of 40.40 ± 3.33% and 39.23 ± 4.84% at a dose of 2.0 mg/kg after 15 min and 30 min of administration, respectively. In terms of measuring percentage decrease of PBG level per DNJ unit, PBI-6DNJ displayed a 2.1-fold enhancement than miglitol, demonstrating a consistency between in vitro and in vivo experiments. This paves the way to the connection between in vivo hypoglycemic potency and in vitro glucosidase inhibition assay, leading to reliable and simplified assessment of hypoglycemic potency determination, and opening a basic understanding of the design of multivalent glucosidase inhibitors.

Lactose azocalixarene drug delivery system for the treatment of multidrug-resistant pseudomonas aeruginosa infected diabetic ulcer.

Diabetic wound is one of the most intractable chronic wounds that is prone to bacterial infection. Hypoxia is an important feature in its microenvironment. However, it is challenging for antimicrobial therapy to directly apply the existing hypoxia-responsive drug delivery systems due to the active targeting deficiency and the biofilm obstacle. Herein, we customizes a hypoxia-responsive carrier, lactose-modified azocalix[4]arene (LacAC4A) with the ability to actively target and inhibit biofilm. By loading ciprofloxacin (Cip), the resultant supramolecular nanoformulation Cip@LacAC4A demonstrates enhanced antibacterial efficacy resulting from both the increased drug accumulation and the controlled release at the site of infection. When applied on diabetic wounds together with multidrug-resistant Pseudomonas aeruginosa infection in vivo, Cip@LacAC4A induces definitely less inflammatory infiltration than free Cip, which translates into high wound healing performance. Importantly, such design principle provides a direction for developing antimicrobial drug delivery systems.