Folic Acid-Doxorubicin-Double-Functionalized-Lipid-Core Nanocapsules: Synthesis, Chemical Structure Elucidation, and Cytotoxicity Evaluation on Ovarian (OVCAR-3) and Bladder (T24) Cancer Cell Lines

Investigation of Eutectic Mixtures of Fatty Acids as a Novel Construct for Temperature-Responsive Drug Delivery

Background

Most of the traditional nanocarriers of cancer therapeutic moieties present dose-related toxicities due to the uptake of chemotherapeutic agents in normal body cells. The severe life-threatening effects of systemic chemotherapy are well documented. Doxorubicin, DOX is the most effective antineoplastic agent but with the least specific action that is responsible for severe cardiotoxicity and myelosuppression that necessitates careful monitoring while administering. Stimuli-sensitive/intelligent drug delivery systems, specifically those utilizing temperature as an external stimulus to activate the release of encapsulated drugs, have become a subject of recent research. Thus, it would be ideal to have a nanocarrier comprising safe excipients and controllable drug release capacity to deliver the drug at a particular site to minimize unwanted and toxic effects of chemotherapeutics. We have developed a simple temperature-responsive nanocarrier based on eutectic mixture of fatty acids. This study aimed to develop, physicochemically characterize and investigate the biological safety of eutectic mixture of fatty acids as a novel construct for temperature-responsive drug release potential.

Methods

We have developed phase change material, PCM, based on a series of eutectic mixtures of fatty acids due to their unique and attractive physicochemical characteristics such as safety, stability, cost-effectiveness, and ease of availability. The reversible solid-liquid phase transition of PCM is responsible to hold firm or actively release the encapsulated drug. The eutectic mixtures of fatty acids (stearic acid and myristic acid) along with liquid lipid (oleic acid) were prepared to exhibit a tunable thermoresponsive platform. Doxorubicin-loaded lipid nanocarriers were successfully developed with combined hot melt encapsulation (HME) and sonication method and characterized to achieve enhanced permeability and retention (EPR) effect-based solid tumor targeting in response to exogenous temperature stimulus. The cytotoxicity against melanoma cell lines and in vivo safety studies in albino rats was also carried out.

Results

Doxorubicin-loaded lipid nanocarriers have a narrow size distribution (94.59-219.3 nm), and a PDI (0.160-0.479) as demonstrated by photon correlation microscopy and excellent colloidal stability (Z.P value: -22.7 to -32.0) was developed. Transmission electron microscopy revealed their spherical morphology and characteristics of a monodispersed system. A biphasic drug release pattern with a triggered drug release at 41°C and 43°C and a sustained drug release was observed at 37°C. The thermoresponsive cytotoxic potential was demonstrated in B16F10 cancer cell lines. Hemolysis assay and acute toxicity studies with drug-free and doxorubicin lipid nanocarrier formulations provided evidence for their non-toxic nature.

Conclusion

We have successfully developed a temperature-responsive tunable platform with excellent biocompatibility and intelligent drug release potential. The formulation components being from natural sources present superior characteristics in terms of cost, compatibility with normal body cells, and adaptability to preparation methods. The reported preparation method is adapted to avoid complex chemical processes and the use of organic solvents. The lipid nanocarriers with tunable thermoresponsive characteristics are promising biocompatible drug delivery systems for improved localized delivery of chemotherapeutic agents.

Folic acid-doxorubicin polymeric nanocapsules: A promising formulation for the treatment of triple-negative breast cancer

Breast cancer is the most common cancers among women and is one of the main causes of morbidity and mortality in this population. In this study, we aimed to conjugate doxorubicin (DOX), a drug widely used in cancer chemotherapy, and folic acid (FA), a ligand targeted for cancer therapy, to lipid-core nanocapsules (LNC), and evaluate the efficacy of the nanoformulation against triple-negative breast cancer (TNBC) MDA-MB-231 cells that overexpress folate receptors (FRs). We performed cell viability assays, quantitative real-time PCR (qRT-PCR), cell migration assay, and clonogenic assay, as well as measured the levels of nitric oxide (NO) generated and cellular uptake. The results showed that the nanoformulation reduced cell viability. The results of qRT-PCR analysis revealed that the nanoformulation induced apoptosis of MDA-MB-231 cells. The mRNA expression levels of Cat and MnSod were increased when the nanoformulation was compared to the doxorubicin solution. Furthermore, the nanoformulation significantly decreased the migration of breast cancer cells in vitro and inhibited colony formation. Additionally, the expression of iNOS in MDA-MB-231 cells was higher when the nanoformulation was used compared to the doxorubicin solution. Cellular uptake was observed after incubating the MDA-MB-231 cells with the fluorescent-labeled nanoformulation. In conclusion, we developed a promising nanoformulation for the treatment of TNBC. Further studies are necessary to demonstrate the in vivo efficacy of this formulation.