Hierarchical Targeted Delivery of Lonidamine and Camptothecin Based on the Ultra-Rapid pH/GSH Response Nanoparticles for Synergistic Chemotherapy

Doxorubicin-loaded Polymeric Biotin-PEG-SeSe-PBLA Micelles with surface Binding of Biotin-Mediated Cancer Cell Targeting and Redox-Responsive Drug release for enhanced anticancer efficacy

Biotin receptors are overexpressed in various cancer cell types, essential in tumor development, metabolism, and metastasis. Chemotherapeutic agents may be more effective and have fewer adverse effects if they specifically target the biotin receptors on cancer cells. Polymeric micelles (PMs) with nanoscale size via the EPR effect to accumulate near tumor tissue. We utilized the solvent exchange technique to crate polymeric Biotin-PEG-SeSe-PBLA micelles. This underwent self-assembly to create uniformly dispersed PMs with a hydrodynamic diameter of 81.54 ± 0.23 nm. The resulting PMs characterized by 1HNMR, 13CNMR, FTIR, and Raman spectroscopy. PMs exhibited a high efficacy of Doxorubicin encapsulation (EE) and loading content (DLC), with values of 5.93 wt% and 74.32 %, respectively. DOX@Biotin-PEG-SeSe-PBLA micelles showed optimal DOX release, around 89 % and 74 % in 10 mM glutathione and 0.1 % H2O2, respectively, within 72 hours, in the simulated cancer redox pool. Fascinatingly, the blank Biotin-PEG-SeSe-PBLA micelles did not affect the HaCaT or HeLa cell lines; approximately 85 % of the cells were metabolically active. Contrarily, at a 5 μg/ml concentration, DOX@Biotin-PEG-SeSe-PBLA specifically inhibited the proliferation of roughly 76 % of HeLa cells and 11 % of HaCaT cells. The fluorescence microscopy results demonstrated that biotin-decorated micelles were more successfully internalized by HeLa cells, which overexpress the biotin receptor, than by non-targeted micelles in vitro. In summary, the diselenide-linked Biotin-PEGSeSe-PBLA formed smart PMs that could offer DOX specific to cancer cells with precision and are physiologically durable.

pH-responsive oxygen self-sufficient smart nanoplatform for enhanced tumor chemotherapy and photodynamic therapy

Premature drug release in chemotherapy and hypoxic conditions in photodynamic therapy (PDT) are perplexing problems in tumor treatment. Thus, it is of great significance to develop the novel therapeutic system with controllable drug release and effective oxygen generation. Herein, a pH-responsive oxygen self-sufficient smart nanoplatform (named DHCCC), integrating hollow mesoporous silica nanoparticles (HMSNs), chitosan (CS), doxorubicin hydrochloride (DOX), chlorin e6 (Ce6) and catalase (CAT), is fabricated to enhance the tumor therapeutic efficacy efficiently through avoiding premature drug release and mitigating hypoxia of tumor microenvironment (TME). The drug DOX can be efficiently loaded into the HMSNs with large cavity and be controllable released because of the pH responsiveness of CS to the weak acidic TME, thereby elevating the chemotherapy efficacy. Meanwhile, CAT can catalyze the decomposition of endogenous hydrogen peroxide in situ generating oxygen to alleviate the hypoxia and enhance the PDT efficiency considerably. In vitro and in vivo results demonstrate that the combined chemo-photodynamic therapy based on the DHCCC nanoplatform exerts more effective antitumor efficacy than chemotherapy or PDT alone. The current study provides a promising inspiration to construct the pH-responsive oxygen self-sufficient smart nanomedicine with potentials to prevent premature drug leakage and overcome hypoxia for efficient tumor therapy.

Rationally designed multifunctional nanoparticles as GSH-responsive anticancer drug delivery systems based on host-guest polymers derived from dextran and β-cyclodextrin

Tumor proliferation and metastasis rely on energy provided by mitochondria. The hexokinase inhibitor lonidamine (LND) could suppress the activities in mitochondria, being a potential antitumor drug. However, limited water-solubility of LND may hinder its biomedical applications. Besides, the cancer-killing effect of LND is compromised by the high level of glutathione (GSH) in cancer cells. Therefore, it is urgent to find a proper method to simultaneously deliver LND and deplete GSH as well as monitor GSH level in cancer cells. Herein, a host polymer β-cyclodextrin-polyethylenimine (β-CD-PEI) and a guest polymer dextran-5-dithio-(2-nitrobenzoic acid) (Dextran-SS-TNB) were synthesized and allowed to form LND-loaded GSH-responsive nanoparticles through host-guest inclusion complexation between β-CD and TNB as host and guest molecular moieties, respectively, which functioned as a system for simultaneous delivery of LND and -SS-TNB species into cancer cells. As a result, the delivery system could deplete GSH and elevate reactive oxygen species (ROS) level in cancer cells, further induce LND-based mitochondrial dysfunction and ROS-based immunogenic cell death (ICD), leading to a synergistic and efficient anticancer effect. In addition, -SS-TNB reacted with GSH to release TNB2-, which could be a probe with visible light absorption at 410 nm for monitoring the GSH level in the cells.

Supramolecular self-assemblies based on water-soluble pillar[6]arene and drug-drug conjugates for the combination of chemotherapy

Although some co-drug delivery systems have been reported to treat cancer, how to optimal design these nano-systems with enhanced therapeutic efficacy is still a major challenge. As for the nitrogen mustard drugs chlorambucil (Cb), the overexpressed glutathione (GSH) in cancer tissue is responsible for their detoxification and reduced bioavailability. In this paper, chlorambucil-oxoplatin (Cb-Pt) was prepared to fabricate water-soluble pillar[6]arene (WP[6]) based supramolecular drug-drug self-assemblies (SDSAs). Remarkably, after the transcytosis by cancer cells, SDSAs was reduced by GSH to re lease Cb and higher toxic cisplatin, accompanying with the declining GSH level and ascending ROS level. Moreover, in vitro and in vivo experiments demonstrated that SDSAs with oxidative stress amplification strategy exhibited excellent therapeutic effect. This strategy might be useful for the synergistic co-drug based chemotherapy field.

Multifunctional carbon quantum dots as a theranostic nanomedicine for fluorescence imaging-guided glutathione depletion to improve chemodynamic therapy

To minimize unwanted reactions with high concentrations of reduced glutathione (GSH) in the tumor microenvironment (TME) during chemodynamic therapy (CDT), a simple and effective strategy was developed to fabricate a TME stimuli-responsive theranostic nanomedicine (Fe-CD) for fluorescence imaging-guided GSH depletion and cancer therapy by combining fluorescent imaging carbon dots (CD) and Fe(III). Introducing Fe(III) into Fe-CD not only quenched the fluorescence of CD while reacting with and consuming intracellular GSH for fluorescence imaging of the depletion of GSH but also provided a source of metal ions to generate more abundant hydroxyl radicals (•OH) with hydrogen peroxide (H₂O₂) through the Fenton reaction to improve CDT. Fe-CD showed promising •OH generation under H₂O₂ to effectively degrade methylene blue in vitro and obviously activate the green fluorescence of the reactive oxygen species (ROS) probe in cells. Benefiting from the fluorescence enhancement in response to TME stimulation, Fe-CD greatly enhanced CDT cytotoxicity while monitoring successful GSH depletion by fluorescence imaging. Fe-CD has the potential to act as a theranostic nanomedicine for fluorescence imaging-guided GSH depletion to amplify CDT.

Novel amphiphilic fluorine-containing nanocarriers for oxygen self-sufficiency "AND" GSH depletion sequentially to enhance photodynamic therapy

In order to maximize the retention of the photodynamic therapy (PDT) efficacy, while avoiding the dilemma of hypoxia and high reducing substances in tumor tissue, fluoropolymers were synthesized in a simple and effective methods. Fluorous effect with good oxygen carrying capacity was endowed by the fluorine-containing section in fluoropolymers and the perfluorodecalin (PFD) together, the reaction site with GSH was provided by the disulfide bond, which enhanced PDT efficiency through the sequential "AND" logic gate design. Two kind of fluorine-containing nanocarriers (M-Ce6 and E-Ce6) were obtained by solvent evaporation or ultrasound emulsification with PFD, respectively. In vitro, both of them showed promising high ROS generation under photoirradiation. Benefiting by cavitation effects, E-Ce6 had a more significant statistical difference in cellular uptake. Furthermore, the cells incubating with E-Ce6 hardly were noticed that the hypoxia signal appeared under hypoxia, while reducing the intracellular GSH content by more than 15%. Through the sequential "AND" logic gate design, ROS production even under hypoxia and GSH conditions of E-Ce6 was also almost 1.5 times that of Ce6 under normoxia. Enhancing effect of E-Ce6 was 13.47 times and 6.85 times, while selectivity ratio reached 5.13 times and 4.81 times compared with Ce6 and M-Ce6. The two-pronged strategy showed a high potential for delivering the Ce6 to deep inside of cancer cells and killing it in the simulated tumor by PDT. These above results demonstrated the potential of E-Ce6, as oxygen self-sufficiency and GSH depletion nanocarriers for combined enhancement of photodynamic therapy.

Investigation of thiolysis of 4-substituted SBD derivatives and rational design of a GSH-selective fluorescent probe

In order to evaluate 7-sulfonamide benzoxadiazole (SBD) derivatives for the development of fluorescent probes, herein we investigated the thiolysis reactivity and selectivity of a series of SBD compounds with different atoms (N/O/S/Se) at the 4-position. Both SBD-amine and SBD-ether are stable toward biothiols in buffer (pH 7.4), while SBD-selenoether can react efficiently with biothiols GSH/Hcy, Cys, and H2S to produce SBD-SG/S-Hcy, SBD-NH-Cys, and SBD-SH, respectively, with three different sets of spectral signals. Therefore, the SBD-selenoether compounds should be useful platforms for the differentiation of these biothiols. Though SBD-alkylthioether shows much lower reactivity than SBD-selenoether, SBD-arylthioether is a tunable motif and structural modifications at the aryl moiety enable the rate of thiol-mediated thiolysis to be modified. To this end, an ER-targeted GSH-selective fluorescent probe 7 was rationally designed via thiolysis of SBD-arylthioether. Compared with control probe SBD-Cl, probe 7 exhibits improved GSH selectivity and better biocompatibility. In total, this study highlights that the modification at the 4-position of SBD is an efficient strategy for the development of new fluorescent probes with tunable reactivity and selectivity.