Preparation, Physicochemical Properties, and In Vitro Toxicity towards Cancer Cells of Novel Types of Arsonoliposomes

Arsonoliposomes (ARSL) are liposomes that incorporate arsonolipids (ARS) in their membranes. They have demonstrated significant toxicity towards cancer cells, while being less toxic towards normal cells. In this study, we sought to investigate the possibility to prepare novel types of arsonoliposomes (ARSL) by incorporating a lipidic derivative of curcumin (TREG) in their membrane, and/or by loading the vesicles with doxorubicin (DOX). The final aim of our studies is to develop novel types of ARSL with improved pharmacokinetics/targeting potential and anticancer activity. TREG was incorporated in ARSL and their integrity during incubation in buffer and serum proteins was studied by monitoring calcein latency. After evaluation of TREG-ARSL stability, the potential to load DOX into ARSL and TREG-ARSL, using the active loading protocol, was studied. Loading was performed at two temperatures (40 °C and 60 °C) and different time periods of co-incubation (of empty vesicles with DOX). Calculation of DOX entrapment efficiency (%) was based on initial and final drug/lipid ratios. The cytotoxic activity of DOX-ARSL was tested towards B16F10 cells (mouse melanoma cells), LLC (Lewis Lung carcinoma cells), and HEK-293 (Human embryonic kidney cells). Results show that TREG-ARSL have slightly larger size but similar surface charge with ARSL and that they are both highly stable during storage at 4 °C for 56 d. Interestingly, the inclusion of TREG in ARSL conferred increased stability to the vesicles towards disruptive effects of serum proteins. The active-loading protocol succeeded to encapsulate high amounts of DOX into ARSL as well as TREG-LIP and TREG-ARSL, while the release profile of DOX from the novel liposome types was similar to that demonstrated by DOX-LIP. The cytotoxicity study results are particularly encouraging, since DOX-ARSL were less toxic towards the (normal) HEK cells compared to the two cancer cell-types. Furthermore, DOX-ARSL demonstrated lower toxicities (at all concentrations tested) for HEK cells, compared to that of the corresponding mixtures of free DOX and empty ARSL, while the opposite was true for the cancer cells (in most cases). The current results justify further in vivo exploitation of DOX-ARSL, as well as TREGARSL as anticancer therapeutic systems.

Organic Arsenicals as Functional Motifs in Polymer and Biomaterials Science

Arsenic (As) exhibits diverse (bio)chemical reactivity and biological activity depending upon its oxidation state. However, this distinctive reactivity has been largely overlooked across many fields owing to concerns regarding the toxicity of arsenic. Recently, a clinical renaissance in the use of arsenicals, including organic arsenicals that are known to be less toxic than inorganic arsenicals, alludes to the possibility of broader acceptance and application in the field of polymer and biomaterials science. Here, current examples of polymeric/macromolecular arsenicals are reported to stimulate interest and highlight their potential as a novel platform for functional, responsive, and bioactive materials.

Arsonoliposomes: preparation and physicochemical characterization

Arsonoliposomes (ARSL) which are liposomes that contain arsonolipids in their membranes have shown interesting anticancer and antiparasitic activity in vitro. Their lipid composition (the specific arsonolipids and/or phospholipids used for their preparation, and the relative amounts of each lipid type) highly influences their physicochemical properties as well as their in vivo kinetics and antiparasitic activity; however, their cytotoxicity towards cancer cells is minimally--if at all--modified. ARSL are prepared by a modification of the "one step" method followed or not by sonication (for formation of sonicated or non-sonicated ARSL, respectively). Arsonoliposomes may be composed only of arsonolipids (containing or not cholesterol) [plain ARSL], or they may contain mixtures of arsonolipids with phospholipids (with or without Chol) [mixed ARSL]. Herein, we describe in detail the preparation and physicochemical characterization of ARSL.