Arsenic trioxide-loaded CalliSpheres: In vitro study of drug release and antitumor activity, and in vivo study of pharmacokinetics, treatment efficacy and safety in liver cancer

Research progress on arsenic, arsenic-containing medicinal materials, and arsenic-containing preparations: clinical application, pharmacological effects, and toxicity

Introduction: The toxicity of arsenic is widely recognized globally, mainly harming human health by polluting water, soil, and food. However, its formulations can also be used for the clinical treatment of diseases such as leukemia and tumors. Arsenic has been used as a drug in China for over 2,400 years, with examples such as the arsenic-containing drug realgar mentioned in Shennong's Herbal Classic. We have reviewed references on arsenic over the past thirty years and found that research has mainly focused on clinical, pharmacological, and toxicological aspects. Results and Discussion: The finding showed that in clinical practice, arsenic trioxide is mainly used in combination with all-trans retinoic acid (ATRA) at a dose of 10 mg/d for the treatment of acute promyelocytic leukemia (APL); realgar can be used to treat acute promyelocytic leukemia, myelodysplastic syndrome, and lymphoma. In terms of pharmacology, arsenic mainly exerts anti-tumor effects. The dosage range of the action is 0.01-80 μmol/L, and the concentration of arsenic in most studies does not exceed 20 μmol/L. The pharmacological effects of realgar include antiviral activity, inhibition of overactivated lactate dehydrogenase, and resistance to malaria parasites. In terms of toxicity, arsenic is toxic to multiple systems in a dose-dependent manner. For example, 5 μmol/L sodium arsenite can induce liver oxidative damage and promote the expression of pro-inflammatory factors, and 15 μmol/L sodium arsenite induces myocardial injury; when the concentration is higher, it is more likely to cause toxic damage.

Thiolated chitosan nanoparticles for stable delivery and smart release of As2O3 for liver cancer through dual actions

In this work, multifunctional thiolated chitosan derivatives (DCA-CS-PEG-FA-NAC) were synthesized, and arsenic trioxide (ATO) was loaded onto the derivatives through glutathione (GSH)-sensitive As^III-S bonds, and stable CS-ATO nanodrugs were prepared by simple self-assembly method. By adjusting the thiol substitution degree of CS, the drug loading capacity of the nanodrugs was significantly improved, which could reach 20 ATO per CS molecule (DCA_10.7-CS-PEG_3.1-FA-NAC_20.2-ATO). In vitro release studies obviously showed the low leakage of ATO under physiological conditions while over 95 % ATO was released after 24 h under GSH. In vitro and in vivo investigations demonstrated that the DCA_10.7-CS-PEG_3.1-FA-NAC_20.2-ATO nanodrug could significantly enhance the tumor intracellular accumulation of ATO, reduce the toxic and side effects of ATO on healthy organs, and improve the therapeutic effect of ATO on the HepG2 mice tumor model (tumor inhibition rate was as high as 86.4 %), indicating the potential application of ATO in clinical treatment of liver cancer.

Nrf2-siRNA Enhanced the Anti-Tumor Effects of As2O3 in 5-Fluorouracil-Resistant Hepatocellular Carcinoma by Inhibiting HIF-1α/HSP70 Signaling

Purpose

Chemoresistance is a major factor contributing to the failure of cancer treatment. The conventional chemotherapy agent 5-fluorouracil (5-FU) has been used for cancer treatment for decades. However, its use is limited in the treatment of hepatocellular carcinoma (HCC) due to acquired resistance. Nrf2 (NF-E2-related factor 2) is known to be associated with drug resistance across a wide range of cancer types. Also, since arsenic trioxide (As₂O₃) showed antitumor effects on HCC, the purpose of this study was to determine whether As₂O₃ and Nrf2-siRNA could inhibit HCC synergistically.

Methods

We generated two separate 5-FU-resistant HCC cell lines (SNU-387/5-FU and Hep3B/5-FU). Western blotting was used to determine protein levels. An efficient lentiviral delivery system was used to establish stable knockdown or overexpression of Nrf2 and HIF-1α. In vitro and in vivo analyses of the effects of Nrf2 gene knockdown and As₂O₃ on 5-FU-resistant HCC cells were conducted.

Results

The expression of Nrf2 was higher in the 5-FU-resistant HCC cell lines than in the parental cell lines. When coupled with Nrf2 knockdown, As₂O₃ treatment significantly decreased 5-FU-resistant SNU-387 and Hep3B cell viability, migration, and invasion, inactivated HIF-1α/HSP70 signaling, inhibited anti-apoptotic B-cell lymphoma (Bcl-2) activity, and increased the expression of pro-apoptotic Bcl-2-associated X protein (BAX) along with caspase-3. The synergistic effect was also confirmed using a 5-FU-resistant Hep3B mouse xenograft model in vivo.

Conclusion

Nrf2 knockdown could improve the effect of As₂O₃ on reversing drug resistance in 5-FU-resistant HCC cells.

One-step fabrication of lidocaine/CalliSpheres® composites for painless transcatheter arterial embolization

BACKGROUND

Transcatheter arterial embolization (TAE) is one of the first-line treatments for advanced hepatocellular cancer. The pain caused by TAE is a stark complication, which remains to be prevented by biomedical engineering methods.

METHODS

Herein, a commercial embolic agent CalliSpheres^® bead (CB) was functionally modified with lidocaine (Lid) using an electrostatic self-assembly technique. The products were coded as CB/Lid-n (n = 0, 5, 10, corresponding to the relative content of Lid). The chemical compositions, morphology, drug-loading, and drug-releasing ability of CB/Lid-n were comprehensively investigated. The biocompatibility was determined by hemolysis assay, live/dead cell staining assay, CCK8 assay, immunofluorescence (IHC) staining assay and quantitative real-time PCR. The thermal withdrawal latency (TWL) and edema ratio (ER) were performed to evaluate the analgesia of CB/Lid-n using a plantar inflammation model. A series of histological staining, including immunohistochemistry (IL-6, IL-10, TGF-β and Navi1.7) and TUNEL were conducted to reveal the underlying mechanism of anti-tumor effect of CB/Lid-n on a VX2-tumor bearing model.

RESULTS

Lid was successfully loaded onto the surface of CalliSpheres^® bead, and the average diameter of CalliSpheres^® bead increased along with the dosage of Lid. CB/Lid-n exhibited desirable drug-loading ratio, drug-embedding ratio, and sustained drug-release capability. CB/Lid-n had mild toxicity towards L929 cells, while triggered no obvious hemolysis. Furthermore, CB/Lid-n could improve the carrageenan-induced inflammation response micro-environment in vivo and in vitro. We found that CB/Lid-10 could selectively kill tumor by blocking blood supply, inhibiting cell proliferation, and promoting cell apoptosis. CB/Lid-10 could also release Lid to relieve post-operative pain, mainly by remodeling the harsh inflammation micro-environment (IME).

CONCLUSIONS

In summary, CB/Lid-10 has relatively good biocompatibility and bioactivity, and it can serve as a promising candidate for painless transcatheter arterial embolization.