TY - JOUR
T1 - Linear Poly(ethylenimine-propylenimine) Random Copolymers for Gene Delivery
T2 - From Polymer Synthesis to Efficient Transfection with High Serum Tolerance
AU - Elzes, M. Rachèl
AU - Mertens, Ine
AU - Sedlacek, Ondrej
AU - Verbraeken, Bart
AU - Doensen, Aniek C.A.
AU - Mees, Maarten A.
AU - Glassner, Mathias
AU - Jana, Somdeb
AU - Paulusse, Jos M.J.
AU - Hoogenboom, Richard
N1 - Funding Information:
J.M.J.P. and M.R.E. gratefully acknowledge funding of this work by the provinces of Overijssel and Gelderland, as well as the project consortium by the Center for Medical Imaging─North East Netherlands (CMI-NEN). R.H. thanks FWO and Ghent University for continuous financial support. O.S. thanks the funding from the FWO and European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no 665501.
Funding Information:
J.M.J.P. and M.R.E. gratefully acknowledge funding of this work by the provinces of Overijssel and Gelderland, as well as the project consortium by the Center for Medical Imaging-North East Netherlands (CMI-NEN). R.H. thanks FWO and Ghent University for continuous financial support. O.S. thanks the funding from the FWO and European Union's Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement no 665501.
Publisher Copyright:
© 2022 American Chemical Society.
PY - 2022/6/13
Y1 - 2022/6/13
N2 - Naturally occurring oligoamines, such as spermine, spermidine, and putrescine, are well-known regulators of gene expression. These oligoamines frequently have short alkyl spacers with varying lengths between the amines. Linear polyethylenimine (PEI) is a polyamine that has been widely applied as a gene vector, with various formulations currently in clinical trials. In order to emulate natural oligoamine gene regulators, linear random copolymers containing both PEI and polypropylenimine (PPI) repeat units were designed as novel gene delivery agents. In general, statistical copolymerization of 2-oxazolines and 2-oxazines leads to the formation of gradient copolymers. In this study, however, we describe for the first time the synthesis of near-ideal random 2-oxazoline/2-oxazine copolymers through careful tuning of the monomer structures and reactivity as well as polymerization conditions. These copolymers were then transformed into near-random PEI-PPI copolymers by controlled side-chain hydrolysis. The prepared PEI-PPI copolymers formed stable polyplexes with GFP-encoding plasmid DNA, as validated by dynamic light scattering. Furthermore, the cytotoxicity and transfection efficiency of polyplexes were evaluated in C2C12 mouse myoblasts. While the polymer chain length did not significantly increase the toxicity, a higher PPI content was associated with increased toxicity and also lowered the amount of polymers needed to achieve efficient transfection. The transfection efficiency was significantly influenced by the degree of polymerization of PEI-PPI, whereby longer polymers resulted in more transfected cells. Copolymers with 60% or lower PPI content exhibited a good balance between high plasmid-DNA transfection efficiency and low toxicity. Interestingly, these novel PEI-PPI copolymers revealed exceptional serum tolerance, whereby transfection efficiencies of up to 53% of transfected cells were achieved even under 50% serum conditions. These copolymers, especially PEI-PPI with DP500 and a 1:1 PEI/PPI ratio, were identified as promising transfection agents for plasmid DNA.
AB - Naturally occurring oligoamines, such as spermine, spermidine, and putrescine, are well-known regulators of gene expression. These oligoamines frequently have short alkyl spacers with varying lengths between the amines. Linear polyethylenimine (PEI) is a polyamine that has been widely applied as a gene vector, with various formulations currently in clinical trials. In order to emulate natural oligoamine gene regulators, linear random copolymers containing both PEI and polypropylenimine (PPI) repeat units were designed as novel gene delivery agents. In general, statistical copolymerization of 2-oxazolines and 2-oxazines leads to the formation of gradient copolymers. In this study, however, we describe for the first time the synthesis of near-ideal random 2-oxazoline/2-oxazine copolymers through careful tuning of the monomer structures and reactivity as well as polymerization conditions. These copolymers were then transformed into near-random PEI-PPI copolymers by controlled side-chain hydrolysis. The prepared PEI-PPI copolymers formed stable polyplexes with GFP-encoding plasmid DNA, as validated by dynamic light scattering. Furthermore, the cytotoxicity and transfection efficiency of polyplexes were evaluated in C2C12 mouse myoblasts. While the polymer chain length did not significantly increase the toxicity, a higher PPI content was associated with increased toxicity and also lowered the amount of polymers needed to achieve efficient transfection. The transfection efficiency was significantly influenced by the degree of polymerization of PEI-PPI, whereby longer polymers resulted in more transfected cells. Copolymers with 60% or lower PPI content exhibited a good balance between high plasmid-DNA transfection efficiency and low toxicity. Interestingly, these novel PEI-PPI copolymers revealed exceptional serum tolerance, whereby transfection efficiencies of up to 53% of transfected cells were achieved even under 50% serum conditions. These copolymers, especially PEI-PPI with DP500 and a 1:1 PEI/PPI ratio, were identified as promising transfection agents for plasmid DNA.
KW - 2023 OA procedure
UR - http://www.scopus.com/inward/record.url?scp=85130059566&partnerID=8YFLogxK
U2 - 10.1021/acs.biomac.2c00210
DO - 10.1021/acs.biomac.2c00210
M3 - Article
C2 - 35499242
AN - SCOPUS:85130059566
SN - 1525-7797
VL - 23
SP - 2459
EP - 2470
JO - Biomacromolecules
JF - Biomacromolecules
IS - 6
ER -