Stability Criterion for the Assembly of Hybrid Lipid-Polymer-Nucleic Acid Nanoparticles

Abstract

Hybrid lipid-polymer-nucleic acid nanoparticles (LPNPs) provide a range of delivery strategies for nonviral gene therapy. However, due to several pairwise interactions between their components, these formulations are difficult to predict and characterize. Here, we employed, for the first time, a novel methodology based on fluorescence cross correlation spectroscopy (FCCS) to directly quantify the extent of association between polycation-DNA cores (polyplexes) and cationic liposome shells. This leads to a rapid and easy evaluation of LPNP formation. As a result, we were able to unveil two critical insights for predicting LPNP assembly. Firstly, the interaction between the polycation (polylysine) and DNA is robust, with the polycation not being displaced by liposomes. Hence, the polyplex cores and liposome shells have to be oppositely charged to associate. Secondly, and most importantly, the liposome:poliplex number ratio (ρN), as opposed to the more common charge ratio, is a critical parameter to predict stable LPNP formation. We find that ρN≥1 is required to ensure that every polyplex is enveloped by a liposome, avoiding the coexistence of oppositely charged species, thus inhibiting aggregation. Since the chosen LPNP components are common, these observations should be applicable to many LPNP systems. Furthermore, this FCCS-based methodology is relevant to other self-assembly composite materials, for applications beyond gene delivery.

Advancing fluorescence microscopy and spectroscopy for the benefit of cell science and drug delivery

“…This methodology promises to become a powerful guide to the development of similar formulations and accelerate research and innovation in mRNA vaccine and cancer vaccine development. As an example, in a recent development as a follow-up of this research, we report on the discovery of a new stability criterion for the preparation of stable hybrid lipid-polymer-nucleic acid nanoparticles [3].…”

Microfluidic synthesis of multilayered lipid–polymer hybrid nanoparticles for the formulation of low solubility drugs

“…16 Class II and class IV (low solubility) categories include many of the newly synthesized drug molecules, 16,17 denoting that the solubility or rate of dissolving in the gastrointestinal tract are the pronounced constrains for their absorption. 18 Various commonly used systems to increase bioavailability of these drug candidates include nanoparticle-based formulations, [19][20][21][22] lipid and polymer-based drug delivery systems, [23][24][25][26][27][28] and pro-drugs. [29][30][31] Winzen et al recently demonstrated that PDMS-b-PMOXA/ cholesterol hybrid vesicles show a drastically increased bending stiffness compared to pure PDMS-b-PMOXA polymersomes and PDMS-b-PMOXA/DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) vesicles which was attributed to a higher packing density due to the presence of cholesterol in hybrid vesicle membranes.…”

“…16 Class II and class IV (low solubility) categories include many of the newly synthesized drug molecules, 16,17 denoting that the solubility or rate of dissolving in the gastrointestinal tract are the pronounced constrains for their absorption. 18 Various commonly used systems to increase bioavailability of these drug candidates include nanoparticle-based formulations, 19–22 lipid and polymer-based drug delivery systems, 23–28 and pro-drugs. 29–31…”