Microfluidic Assembly of pDNA/Cationic Liposome Lipoplexes with High pDNA Loading for Gene Delivery

Abstract

Microfluidics offers unique characteristics to control the mixing of liquids under laminar flow. Its use for the assembly of lipoplexes represents an attractive alternative for the translation of gene delivery studies into clinical trials on a sufficient throughput scale. Here, it was shown that the microfluidic assembly of pDNA/cationic liposome (CL) lipoplexes allows the formation of nanocarriers with enhanced transfection efficiencies compared with the conventional bulk-mixing (BM) process under high pDNA loading conditions. Lipoplexes generated by microfluidic devices exhibit smaller and more homogeneous structures at a molar charge ratio (R±) of 1.5, representing the ratio of lipid to pDNA content. Using an optimized model to fit small-angle X-ray scattering (SAXS) curves, it was observed that large amounts of pDNA induces the formation of aggregates with a higher number of stacked bilayers (N ∼ 5) when the BM process was used, whereas microfluidic lipoplexes presented smaller structures with a lower number of stacked bilayers (N ∼ 2.5). In vitro studies further confirmed that microfluidic lipoplexes achieved higher in vitro transfection efficiencies in prostate cancer cells at R ± 1.5, employing a reduced amount of cationic lipid. The correlation of mesoscopic characteristics with in vitro performance provides insights for the elucidation of the colloidal arrangement and biological behavior of pDNA/CL lipoplexes obtained by different processes, highlighting the feasibility of applying microfluidics to gene delivery.

Lipid Nanovesicles by Microfluidics: Manipulation, Synthesis, and Drug Delivery

“…A cross‐junction microchannel was used to generate liposome‐pDNA nanocomplexes by mixing aqueous liposomes with nucleic acids. These nanocomplexes exhibited a smaller size with a lower number of stacked bilayer ( N ≈ 2.5) than bulk synthesis (Figure a) . Through optimization of the molar ratio of lipids and genes within the microfluidic device, liposome‐pDNA nanocomplexes achieved high gene delivery efficiency.…”

“…a) Lipid–nucleic acid nanocomplexes. Reproduced with permission . Copyright 2018, American Chemical Society.…”

Microfluidics for Cancer Nanomedicine: From Fabrication to Evaluation

“…Unlike conventional methods requiring complicated procedures and weak control over encapsulation efficiency, microfluidic platforms allowed a rapid and facile encapsulation of hydrophilic agents in nanocarriers with well‐controlled properties. Balbino investigated the assembly of pDNA–cationic‐liposome (CL) lipoplexes using both a 2D HFF microfluidic device and a conventional bulk mixer. Compared to bulk mixing, the microfluidic assembly of lipoplexes exhibited smaller and more homogeneous structures under high pDNA loading conditions, which enabled increased transfection efficiency.…”

Rotas Microfluídicas Para a Produção De Lipossomas Do Tipo Stealth

“…No trabalho realizado por Balbino et al (2016), os autores mostraram que os lipoplexos (lipossomas complexados com DNA) produzidos em dispositivos microfluídicos apresentaram maior capacidade de carreamento de material genético e maior eficiência de transfecção do que os lipoplexos produzidos por processos convencionais (mistura seguida de incubação).…”