NANOENCAPSULATION OF BETANIN PURIFIED FROM RED BEETROOT EXTRACTS IN CHITOSAN MATRIX BY IONIC GELATION METHOD

DI SANTO, CAROLINA; SAMANIEGO LOPEZ, CECILIA; PEREZ, OSCAR

Encuentro; Reunión Conjunta SAIC. SAI. AAFE. NANOMED-AR; 2021

Sociedad Argentina de Investigación Clínica, Sociedad Argentina de Inmunologia, Asociacion Argentina de Nanomedicina y Asociación Argentina de Fomento Equino

Betanin (BET: betanidin 5-O-β-glucoside) is a pigment with powerful antioxidant properties but labile to harsh environmental conditions. The radical scavenging activity of BET has been associated with several health benefits including anticancer properties. BET is also the most abundant component of the processed beetroot (Beta vulgaris) juice. Chitosan (CS) is a food grade, biocompatible and non-toxic biopolymer used as encapsulation material by virtue of its reactive -NH2 and -OH groups along the molecule. In this work we have purified BET from beetroot juice by means of size exclusion chromatography (sephadex LH-20) and encapsulated into CS by ionic gelation method. The purified BET fractions were analysed by TLC (Thin Layer Chromatography) and UV-visible spectroscopy and compared with standard commercial BET. Spectroscopy analysis showed that BET has a prominent presence in the purified fractions. From 51,5 ± 2,6 mL of juice/100 g of beetroot we obtained 54 ± 13 mg of purified BET/mL of juice. Purified BET was lyophilized and incorporated into CS solutions (0,7 % w/w, pH 5.5) by using tripolyphosphate (TPP; 0,6 % w/w, pH 9.0) as crosslinking agent. A maximum encapsulation efficiency (42 ± 6 %) was reached when using the 3:1 CS/TPP relation (w/w). The mean size of nanoparticles (NP) was 239 ± 17 nm assessed by DLS (Dynamic light Scattering), with a low polydispersity index (0,322 ± 0,004) and was dependent on a previous ultrasonication step to prevent aggregation. The stability in water (pH 5.0) of NP-loaded BET was observed throughout several days. On the contrary, a fast liberation of BET occurred in the PBS buffer (pH 7.0), showing differential retention properties depending on vehicle and pH conditions. These preliminary results show that BET-CS-TPP NP could be suitable nanocarriers for BET protection and delivery. The maintenance of BET antioxidant properties after incorporation into NP and their biomedical applications should be determined further.