Discovery of highly potent and selective 7-ethyl-10-hydroxycamptothecin-glucose conjugates as potential anti-colorectal cancer agents

Enhanced Antitumor Efficacy and Reduced Toxicity in Colorectal Cancer Using a Novel Multifunctional Rg3- Targeting Nanosystem Encapsulated with Oxaliplatin and Calcium Peroxide

Purpose

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths worldwide. Oxaliplatin (OXA) is currently the primary chemotherapeutic agent for CRC, but its efficacy is limited by the tumor microenvironment (TME). Here, we present a combined approach of chemotherapy and TME modulation for CRC treatment. A multifunctional nanosystem (Rg3-Lip-OXA/CaO2) was established using Ginsenoside Rg3 liposomes targeting glucose transporter 1 overexpressed on the surface of CRC cells to co-deliver OXA and calcium peroxide (CaO2).

Methods

The CaO2 nanoparticles were synthesized via the CaCl2-H2O2 reaction under alkaline conditions and characterized using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Rg3-Lip-OXA/CaO2 was prepared through a thin-film hydration approach and characterized; additionally, its stability and release behavior were studied. The O2, H2O2, and Ca2+ generation ability of Rg3-Lip-OXA/CaO2 in solution and HCT116 cells were measured. The in vitro cellular uptake was observed via fluorescence microscope and flow cytometry. In vitro cytotoxicity was evaluated using the CCK-8 assay, flow cytometry, and live/dead cell staining. The in vivo targeting effect as well as antitumor efficacy were determined in HCT116 tumor-bearing mice. Finally, the acute toxicity of Rg3-Lip-OXA/CaO2 was investigated in ICR mice to explore its safety.

Results

The XRD and XPS analyses confirmed the successful synthesis of CaO2 nanoparticles. The Rg3-Lip-OXA/CaO2 exhibited an average particle size of approximately 92.98 nm with good stability and sustained release behavior. In vitro and in vivo studies confirmed optimal targeting by Rg3-Lip and demonstrated that the nanosystem effectively produced O2, H2O2 and Ca2+, resulting in significant cytotoxicity. Additionally, in vivo studies revealed substantial tumor growth suppression and reduced tumor-associated fibroblasts (TAFs) and collagen. Acute toxicity studies indicated that Rg3-Lip-OXA/CaO2 markedly reduced the toxicity of chemotherapeutic drugs.

Conclusion

This multifunctional nanosystem enhances chemotherapy efficacy and reduces toxicity, offering a promising approach for optimizing CRC treatment and potential clinical application.

Nanomaterials modulate tumor-associated macrophages for the treatment of digestive system tumors

The treatment of digestive system tumors presents challenges, particularly in immunotherapy, owing to the advanced immune tolerance of the digestive system. Nanomaterials have emerged as a promising approach for addressing these challenges. They provide targeted drug delivery, enhanced permeability, high bioavailability, and low toxicity. Additionally, nanomaterials target immunosuppressive cells and reshape the tumor immune microenvironment (TIME). Among the various cells in the TIME, tumor-associated macrophages (TAMs) are the most abundant and play a crucial role in tumor progression. Therefore, investigating the modulation of TAMs by nanomaterials for the treatment of digestive system tumors is of great significance. Here, we present a comprehensive review of the utilization of nanomaterials to modulate TAMs for the treatment of gastric cancer, colorectal cancer, hepatocellular carcinoma, and pancreatic cancer. We also investigated the underlying mechanisms by which nanomaterials modulate TAMs to treat tumors in the digestive system. Furthermore, this review summarizes the role of macrophage-derived nanomaterials in the treatment of digestive system tumors. Overall, this research offers valuable insights into the development of nanomaterials tailored for the treatment of digestive system tumors.

Research Progress of SN38 Drug Delivery System in Cancer Treatment

The active metabolite of irinotecan (CPT-11), 7-ethyl-10-hydroxycamptothecin (SN38), is 100-1000 times more active than CPT-11 and has shown inhibitory effects on a range of cancer cells, including those from the rectal, small cell lung, breast, esophageal, uterine, and ovarian malignancies. Despite SN38's potent anticancer properties, its hydrophobicity and pH instability have caused substantial side effects and anticancer activity loss, which make it difficult to use in clinical settings. To solve the above problems, the construction of SN38-based drug delivery systems is one of the most feasible methods to improve drug solubility, enhance drug stability, increase drug targeting ability, improve drug bioavailability, enhance therapeutic efficacy and reduce adverse drug reactions. Therefore, based on the targeting mechanism of drug delivery systems, this paper reviews SN38 drug delivery systems, including polymeric micelles, liposomal nanoparticles, polymeric nanoparticles, protein nanoparticles, conjugated drug delivery systems targeted by aptamers and ligands, antibody-drug couplings, magnetic targeting, photosensitive targeting, redox-sensitive and multi-stimulus-responsive drug delivery systems, and co-loaded drug delivery systems. The focus of this review is on nanocarrier-based SN38 drug delivery systems. We hope to provide a reference for the clinical translation and application of novel SN38 medications.

Structural Modification Endows Small-Molecular SN38 Derivatives with Multifaceted Functions

As a camptothecin derivative, 7-ethyl-10-hydroxycamptothecin (SN38) combats cancer by inhibiting topoisomerase I. SN38 is one of the most active compounds among camptothecin derivatives. In addition, SN38 is also a theranostic reagent due to its intrinsic fluorescence. However, the poor water solubility, high systemic toxicity and limited action against drug resistance and metastasis of tumor cells of SN38 indicates that there is great space for the structural modification of SN38. From the perspective of chemical modification, this paper summarizes the progress of SN38 in improving solubility, increasing activity, reducing toxicity and possessing multifunction and analyzes the strategies of structure modification to provide a reference for drug development based on SN38.