Perillaldehyde 1,2-epoxide loaded SLN-tailored mAb: production, physicochemical characterization and in vitro cytotoxicity profile in MCF-7 cell lines

We have developed a new cationic solid lipid nanoparticle (SLN) formulation, composed of Compritol ATO 888, poloxamer 188 and cetyltrimethylammonium bromide (CTAB), to load perillaldehyde 1,2-epoxide, and surface-tailored with a monoclonal antibody for site-specific targeting of human epithelial growth receptor 2 (HER2). Perillaldehyde 1,2-epoxide-loaded cationic SLN (cPa-SLN), with a mean particle size (z-Ave) of 275.31 ± 4.78 nm and polydispersity index (PI) of 0.303 ± 0.081, were produced by high shear homogenization. An encapsulation efficiency of cPa-SLN above 80% was achieved. The release of perillaldehyde 1,2-epoxide from cationic SLN followed the Korsemeyer–Peppas kinetic model, which is typically seen in nanoparticle formulations. The lipid peroxidation of cPa-SLN was assessed by the capacity to produce thiobarbituric acid-reactive substances, while the antioxidant activity was determined by the capacity to scavenge the stable radical DPPH. The surface functionalization of cPa-SLN with the antibody was done via streptavidin-biotin interaction, monitoring z-Ave, PI and ZP of the obtained assembly (cPa-SLN-SAb), as well as its stability in phosphate buffer. The effect of plain cationic SLN (c-SLN, monoterpene free), cPa-SLN and cPa-SLN-SAb onto the MCF-7 cell lines was evaluated in a concentration range from 0.01 to 0.1 mg/mL, confirming that streptavidin adsorption onto cPa-SLN-SAb improved the cell viability in comparison to the cationic cPa-SLN. The authors wish to acknowledge the financial support from CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico, from CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior), and from FAPITEC/SE (Fundação de Apoio à Pesquisa e Inovação Tecnológica do Estado de Sergipe). E.B. Souto acknowledges the sponsorship of the projects M-ERA-NET-0004/2015-PAIRED and UIDB/04469/2020, receiving support from the Portuguese Science and Technology Foundation, Ministry of Science and Education (FCT/MEC) through national funds, and co-financed by FEDER, under the Partnership Agreement PT2020.