Controlling complexation/decomplexation and sizes of polymer-based electrostatic pDNA polyplexes is one of the key factors in effective transfection

• Published in: Colloids and surfaces, B, Biointerfaces B, Biointerfaces, 2019-12, Vol.184, p.110497-110497, Article 110497
• Main Authors: Kim, Kyoungnam, Hwang, Hee Sook, Shim, Min Suk, Cho, Yong-Yeon, Lee, Joo Young, Lee, Hye Suk, Kang, Han Chang
• Format: Article
• Language: English
• Subjects: Active Transport, Cell Nucleus; Adenosine Triphosphate - chemistry; Adenosine Triphosphate - metabolism; ATP; Cell Nucleus - metabolism; Complexation/decomplexation; Cytoplasm - metabolism; DNA - chemistry; DNA - genetics; DNA - pharmacokinetics; Drug Liberation; HEK293 Cells; Hep G2 Cells; Humans; Particle Size; Plasmids - chemistry; Plasmids - genetics; Plasmids - pharmacokinetics; Poly(L-lysine); Polylysine - chemistry; Polymeric gene delivery; Polymers - chemistry; Size; Static Electricity; Transfection - methods
• ISSN: 0927-7765; 1873-4367
• DOI: 10.1016/j.colsurfb.2019.110497

[Display omitted] •Gene complexation affinity of polycation controls tightness and size of polyplex.•Smaller, tighter polyplex delivered more pDNA into nucleus than larger, looser one.•Larger polyplex had slower cytosolic and nuclear transport of pDNA than smaller one.•Too tighter polyplex made poor gene expression due to poor pDNA release in nucleus.•Tightness and size of polyplex strongly influence polymeric gene transfection. The delivery of plasmid DNA (pDNA) using polycations has been investigated for several decades; however, obstacles that limit efficient gene delivery still hinder the clinical application of gene therapy. One of the major limiting factors is controlling pDNA binding affinity with polymers to control the complexation and decomplexation of polyplexes. To address this challenge, polycations of α-poly(L-lysine) (APL) and ε-poly(L-lysine) (EPL) were used to prepare variable complexation/decomplexation polyplexes with binding affinities ranging from too tight to too loose and sizes ranging from small to large. APL-EPL/ATP-pDNA polyplexes were also prepared to compare the effects of endosomolytic ATP on complexation/decomplexation and the sizes of polyplexes. The results showed that smaller and tighter polyplexes delivered more pDNA into the cells and into the nucleus than the larger and looser polyplexes. Larger polyplexes exhibited slower cytosolic transport and consequently less nuclear delivery of pDNA than smaller polyplexes. Tighter polyplexes exhibited poor pDNA release in the nucleus, leading to no improvement in transfection efficiency. Thus, polyplexes should maintain a balance between complexation and decomplexation and should have optimal sizes for effective cellular uptake, cytosolic transport, nuclear import, and gene expression. Understanding the effects of complexation/decomplexation and size is important when designing effective polymer-based electrostatic gene carriers.