Development of a trilipid-based liposome system as a delivery vector for plasmid DNA in an MCF-7 cell line: Preparation, optimization, physical characterization and In Vitro cytotoxicity evaluation

Breast cancer cases have recorded an increase for the past decade globally. Currently, available treatments affect patients both physically and mentally, prompting the development of a safer alternative treatment, such as gene therapy. Clinical trials mainly utilise viruses to deliver genes though it has adverse immunological issues. Thus, non-viral vectors such as liposomes, an alternative delivery system without immunological problems, are extensively considered. Liposomes, consisting of lipid bilayers made into nanoparticles as a form of the delivery system, encompass a therapeutic gene cargo to protect and efficiently traverse through the biological barriers for effective gene delivery. Various liposome formulations involving DPPC, OCTA and CHOL lipids were investigated. The optimum method was developed for formulating liposomes which involved several methods and techniques producing particles of below ∼300 nm in size and was confirmed via TEM imaging forming spherical agglomeration. The cytotoxicity of the liposome and nucleic acid complexes was determined using MTT cytotoxicity assay with ∼65% cell viability at 2 µg/µl (w/v) concentration, a higher concentration used compared to those published in the literature (µg/ml). Through this work, a formulation of liposome consisting of DPPC:OCTA:CHOL at 18:72:10 ratio with a reporter gene (pEGFP) was developed and has shown promising size properties, zeta potential, encapsulation efficiency with a capacity to use at a higher concentration as a potential non-viral gene therapy carrier for utilization in MCF-7 breast cancer cell line.