Polycationic cyclodextrin nanoparticles induce apoptosis and affect antitumoral activity in HepG2 cell line: An evaluation at the molecular level

Chitosan and Cyclodextrins-Versatile Materials Used to Create Drug Delivery Systems for Gastrointestinal Cancers

Gastrointestinal cancers are characterized by a frequent incidence, a high number of associated deaths, and a tremendous burden on the medical system and patients worldwide. As conventional chemotherapeutic drugs face numerous limitations, researchers started to investigate better alternatives for extending drug efficacy and limiting adverse effects. A remarkably increasing interest has been addressed to chitosan and cyclodextrins, two highly versatile natural carbohydrate materials endowed with unique physicochemical properties. In this respect, numerous studies reported on fabricating various chitosan and cyclodextrin-based formulations that enabled prolonged circulation times, improved cellular internalization of carried drugs, preferential uptake by the targeted cells, reduced side effects, enhanced apoptosis rates, and increased tumor suppression rates. Therefore, this paper aims to briefly present the advantageous properties of these oligo- and polysaccharides for designing drug delivery systems, further focusing the discussion on nanocarrier systems based on chitosan/cyclodextrins for treating different gastrointestinal cancers. Specifically, there are reviewed studies describing promising solutions for colorectal, liver, gastric, pancreatic, and other types of cancers of the digestive system towards creating an updated framework of what concerns anticancer chitosan/cyclodextrin-based drug delivery systems.

Synergistic Antitumor Potency of a Self-Assembling Cyclodextrin Nanoplex for the Co-Delivery of 5-Fluorouracil and Interleukin-2 in the Treatment of Colorectal Cancer

Chemotherapy is the most used method after surgery in the treatment of colon cancer. Cancer cells escape the recognition mechanism of immune system cells to survive and develop chemoresistance. Therefore, the use of immunotherapy in combination with chemotherapy can increase the effectiveness of the treatment. Nanoparticles have been used clinically to increase the accumulation of therapeutics in target tissues and reduce toxicity. In this paper, nanoplexes were formed via cationic cyclodextrin polymer, 5-Fluorouracil, and Interleukin-2 based on the opposite charge interaction of macromolecules without undergoing any structural changes or losing the biological activity of Interleukin-2. Anticancer activities of nanoplexes were determined in two-dimensional and three-dimensional cell culture setups. The dual drug-loaded cyclodextrin nanoplexes diffused deeper into the spheroids and accelerated apoptosis when compared with 5-FU solutions. In the colorectal tumor-bearing animal model, survival rate, antitumor activity, metastasis, and immune response parameters were assessed using a cyclodextrin derivative, which was found to be safe based on the ALT/AST levels in healthy mice. Histomorphometric analysis showed that the groups treated with the nanoplex formulation had significantly fewer initial tumors and lung foci when compared with the control. The dual drug-loaded nanoplex could be a promising drug delivery technique in the immunochemotherapy of colorectal cancer.

A different approach to immunochemotherapy for colon Cancer: Development of nanoplexes of cyclodextrins and Interleukin-2 loaded with 5-FU

Immune system deficiencies are crucial in the progression of cancer, predominantly because immune cells are not stimulated by cytokines to eradicate cancer cells. Immunochemotherapy is currently considered an innovative approach that creates pathways in cancer treatment, sometimes also aiding in the efficacy of chemotherapeutics. The aim of this study was to prepare a cyclodextrin (CD) nanoplex based on charge interaction to deliver the anticancer drug 5-fluorouracil (5-FU) and Interleukin-2 (IL-2), thereby forming a nanoscale drug delivery system aimed at chemo-immunotherapy for colorectal cancers. The CD:IL-2 nanoplexes were obtained with a particle size below 100 nm and a cationic surface charge based on the extent of charge interaction of the cationic CD polymer with negatively charged IL-2. The loading capacity of CD nanoplexes was 40% for 5-FU and 99.8% for IL-2. Nanoplexes maintained physical stability in terms of particle size and zeta potential in aqueous solution for 1 week at + 4 °C. Moreover, the structural integrity of IL-2 loaded into CD nanoplexes was confirmed by SDS-PAGE analysis. The cumulative release rates of both 5-FU and IL-2 were found to be more than 80% in simulated biological fluids in 12 h. Cell culture studies demonstrate that CD polymers are safe on healthy L929 mouse fibroblast cells. Drug-loaded CD nanoplexes were determined to have a higher anticancer effect than free drug solution against CT26 mouse colon carcinoma cells. In addition, intestinal permeability studies supported the conclusion that CD nanoplexes could be promising candidates for oral chemotherapy as well. In conclusion, effective cancer therapy utilizing the absorptive/cellular uptake effect of CDs, the synergic effect and co-transport of chemotherapeutic drugs and immunotherapeutic molecules is a promising approach. Furthermore, the transport of IL-2 with this nano-sized system can reduce or avoid its toxicity problem in the clinic.

Assessment of the Biocompatibility of Cucurbiturils in Blood Cells

Currently, cucurbiturils are being actively researched all over the world. Research is focused on the ways of improving the solubility and selectivity of cucurbiturils, increasing the stability of the complexes with other particles in various media and enhancing their ability to bind and release various substances. The most significant area of our research is the assessment of safety, studying the biological properties and synergistic effects of cucurbiturils during complexation with drugs. In this article, the hemocompatibility of erythrocytes and leukocytes with cucurbiturils was investigated. We demonstrated that cucurbiturils have no cytotoxic effect, even at high concentrations (1 mM) and do not affect the viability of PBMCs. However, cucurbiturils can increase the level of the early apoptosis of lymphocytes and cucurbit[7]uril enhances hemolysis in biologically relevant media. Despite this, cucurbiturils are fairly safe organic molecules in concentrations up to 0.3 mM. Thus, we believe that it will become possible to use polymer nanostructures as drug delivery systems in clinical practice, since cucurbiturils can be modified to improve pharmacological properties.