Functional interaction of hybrid extracellular vesicle-liposome nanoparticles with target cells: absence of toxicity

Drug delivery platforms, complex lipid nanoparticles (LNPs) and extracellular vesicles (EVs) have both faced a number of key challenges ranging from organ specificity to loading capacity and stability. A key challenge in EV biology as well as LNP design remains vesicle to cell interaction and the creation of a polar permeability pathway necessary for cargo exchange. Membrane to membrane recognition and intercalation are tantamount to delivery and integral to function of both EVs and LNPs, both complex and single component. We reasoned that the overlapping advantages of both nanoparticles centered on compositional lipids. EVs are encapsulations using biological membrane lipids and expressed proteins and have a larger carrier capacity. LNPs are composed of synthetic lipids differing in charge and amount mimicking those present in biological membranes and include a synthetic lipid of choice that carries a charge, designed to enhance biological membrane disruption and subsequent cargo off-loading. Our goal was to design hybrid EVs (HEVs) that combined both elements. We manufactured positively charged liposomes (Lip) carrying mRNA coding for fluorescent proteins to load isolated EVs in order to create a combinatorial delivery platform. Using knowledge from LNP-based mRNA vaccine delivery, we have formulated and characterized HEVs. Future therapeutic strategies could involve isolating EVs from patients, hybridizing them with synthetic lipids loaded with desired payloads, and reintroducing them to the patient. This approach is particularly relevant for enhancing the function of pulmonary innate immunity in diseases like cystic fibrosis, chronic granulomatous disease, and pulmonary fibrosis. By conducting both in-vitro and in-vivo assays, we demonstrate that HEVs exhibit comparable transfection efficacy to LNPs composed of complex synthetic lipids, while significantly reducing cytotoxicity. This highlights their potential as safer and more efficient delivery vehicles.