Lipodendriplexes: A promising nanocarrier for enhanced gene delivery with minimal cytotoxicity

Non-viral vectors are a safe, efficient and non-toxic alternative to viral vectors for gene therapy against many diseases ranging from genetic disorders to cancers. Polyamidoamine (PAMAM), a positively charged dendrimer has a tendency to complex with nucleic acids (to form dendriplexes) like plasmid DNA (pDNA) and small interfering RNA (siRNA) and can shield them from enzymatic degradation, thereby facilitating endocytosis and endosomal release. In this study, we developed an advanced variant of the dendriplexes by encapsulating them within liposomes to enhance their gene delivery efficiency. This liposome encapsulated dendriplex system can further reduce unwanted cytotoxicity and enhance cellular uptake of nucleic acids. A broad range of lipid combinations were used to optimize the lipodendriplexes in terms of their physicochemical characteristics including size, shape and zeta potential. The optimized lipodendriplexes were tested for pDNA transfection, in vitro cell viability, cellular uptake, siRNA mediated knockdown, hemocompatibility, metastatic progression and in ovo in chorioallantoic membrane model (CAM). The optimized system has shown significant improvement in pDNA transfection (p < 0.01) with higher GFP expression and gene silencing and has shown improved cell viability (p < 0.05) compared to the parent dendriplex system. The hemocompatibility and CAM analysis, revealed an efficient yet biocompatible gene delivery system in the form of lipodendriplexes.