Design of Pegylated-Nanocapsules to Diphenyl Diselenide Administration: in Vitro Evidence of Hemocompatible and Selective Antiglioma Formulation

Diphenyl diselenide [(PhSe)2] is a pleiotropic pharmacological agent, but it has low aqueous solubility. The nanoencapsulation of (PhSe)2 allowed the preparation of an aqueous formulation as well as potentiated its in vitro antitumor effect and the effectiveness in a preclinical model of glioblastoma when administered by the intragastric route. Thus, aiming at maximizing the therapeutic potential of (PhSe)2, the present study designed a pegylated-formulation intending to intravenous administration of the (PhSe)2 as a new approach for glioma therapy. The poly(Ɛ-caprolactone) nanocapsules containing (PhSe)2 were physically coated with polyethyleneglycol (PEG) using the preformed polymer interfacial deposition technique and evaluated through physicochemical, morphological, spectroscopic, and thermal characteristics. Hemocompatibility was determined by the in vitro hemolysis test and cytotoxicity assays were performed in astrocytes and glioma C6 cells (10–100 μM). The pegylated-nanocapsules had an average diameter of 218 ± 25 nm, polydispersity index of 0.164 ± 0.046, zeta potential of − 8.1 ± 1.6 mV, pH 6.0 ± 0.09, (PhSe)2 content of 102.00 ± 3.57%, and encapsulation efficiency around 98%. Besides, the (PhSe)2 pegylated-nanocapsules were spherical, presented absence of chemical interaction among the constituents, and showed higher thermal stability than the non-encapsulated materials. PEG-coated nanocapsules did not cause hemolytic effect while formulations without PEG induced a hemolysis rate above 10%. Moreover, pegylated-nanocapsules had superior in vitro antiglioma effect in comparison to free compound (IC50: 24.10 μM and 74.83 μM, respectively). Therefore, the (PhSe)2-loaded pegylated-nanocapsule suspensions can be considered a hemocompatible formulation for the glioma treatment by the intravenous route.