TY - JOUR
T1 - Synthesis and application of poly(ethylene glycol)-co-poly(β-amino ester) copolymers for small cell lung cancer gene therapy
AU - Kim, Jayoung
AU - Kang, Yechan
AU - Tzeng, Stephany Y.
AU - Green, Jordan J.
N1 - Funding Information:
H446 and IMR-90 cells were provided by Dr. Christine Lee Hann and Dr. Linzhao Cheng. Ron Shmueli is thanked for assistance with preliminary studies in the synthesis of PEG-PBAE. This work was in part supported by the NIH ( R01EB016721 ). The authors also thank the Imaging and Microscopy Core Module of the Wilmer Core Grant, P30-EY001865. JK thanks Samsung Scholarship for fellowship support.
Publisher Copyright:
© 2016 Acta Materialia Inc.
PY - 2016/9/1
Y1 - 2016/9/1
N2 - The design of polymeric nanoparticles for gene therapy requires engineering of polymer structure to overcome multiple barriers, including prolonged colloidal stability during formulation and application. Poly(β-amino ester)s (PBAEs) have been shown effective as polymeric vectors for intracellular DNA delivery, but limited studies have focused on polymer modifications to enhance the stability of PBAE/DNA polyplexes. We developed block copolymers consisting of PBAE oligomer center units and poly(ethylene glycol) (PEG) end units. We fabricated a library of PEG-PBAE polyplexes by blending PEGylated PBAEs of different PEG molecular weights and non-PEGylated PBAEs of different structures at various mass ratios of cationic polymer to anionic DNA. Non-PEGylated PBAE polyplexes aggregated following a 24 h incubation in acidic and physiological buffers, presenting a challenge for therapeutic use. In contrast, among 36 PEG-PBAE polyplex formulations evaluated, certain polyplexes maintained a small size under these conditions. These selected polyplexes were further evaluated for transfection in human small cell lung cancer cells (H446) in the presence of serum, and the best formulation transfected ∼40% of these hard-to-transfect cells while preventing polymer-mediated cytotoxicity. When PEG-PBAE polyplex delivered Herpes simplex virus thymidine kinase plasmid in combination with the prodrug ganciclovir, the polyplexes killed significantly more H446 cancer cells (35%) compared to healthy human lung fibroblasts (IMR-90) (15%). These findings indicate that PEG-PBAE polyplexes can maintain particle stability without compromising their therapeutic function for intracellular delivery to human small cell lung cancer cells, demonstrate potential cancer specificity, and have potential as safe materials for small cell lung cancer gene therapy. Statement of Significance Many natural and synthetic biomaterials have been investigated as non-viral vectors to deliver nucleic acids for cancer therapy. However, there are multiple hurdles to successful transfection including achieving particle stability, efficient delivery to cancer cells, and low cytotoxicity. In particular, engineering the physicochemical surface properties of a nanoparticle to improve stability is often offset by a decrease in the cellular entry and transfection efficiency. We developed stable polymeric nanoparticles that demonstrate high transfection efficiency by modifying synthetic biodegradable cationic polymers and engineering nanoparticle formulations using a combinatorial approach. The results of this study show the potential of biodegradable surface-modified polymeric nanoparticles as clinically translatable, biomaterial-based vehicles for cancer gene therapy.
AB - The design of polymeric nanoparticles for gene therapy requires engineering of polymer structure to overcome multiple barriers, including prolonged colloidal stability during formulation and application. Poly(β-amino ester)s (PBAEs) have been shown effective as polymeric vectors for intracellular DNA delivery, but limited studies have focused on polymer modifications to enhance the stability of PBAE/DNA polyplexes. We developed block copolymers consisting of PBAE oligomer center units and poly(ethylene glycol) (PEG) end units. We fabricated a library of PEG-PBAE polyplexes by blending PEGylated PBAEs of different PEG molecular weights and non-PEGylated PBAEs of different structures at various mass ratios of cationic polymer to anionic DNA. Non-PEGylated PBAE polyplexes aggregated following a 24 h incubation in acidic and physiological buffers, presenting a challenge for therapeutic use. In contrast, among 36 PEG-PBAE polyplex formulations evaluated, certain polyplexes maintained a small size under these conditions. These selected polyplexes were further evaluated for transfection in human small cell lung cancer cells (H446) in the presence of serum, and the best formulation transfected ∼40% of these hard-to-transfect cells while preventing polymer-mediated cytotoxicity. When PEG-PBAE polyplex delivered Herpes simplex virus thymidine kinase plasmid in combination with the prodrug ganciclovir, the polyplexes killed significantly more H446 cancer cells (35%) compared to healthy human lung fibroblasts (IMR-90) (15%). These findings indicate that PEG-PBAE polyplexes can maintain particle stability without compromising their therapeutic function for intracellular delivery to human small cell lung cancer cells, demonstrate potential cancer specificity, and have potential as safe materials for small cell lung cancer gene therapy. Statement of Significance Many natural and synthetic biomaterials have been investigated as non-viral vectors to deliver nucleic acids for cancer therapy. However, there are multiple hurdles to successful transfection including achieving particle stability, efficient delivery to cancer cells, and low cytotoxicity. In particular, engineering the physicochemical surface properties of a nanoparticle to improve stability is often offset by a decrease in the cellular entry and transfection efficiency. We developed stable polymeric nanoparticles that demonstrate high transfection efficiency by modifying synthetic biodegradable cationic polymers and engineering nanoparticle formulations using a combinatorial approach. The results of this study show the potential of biodegradable surface-modified polymeric nanoparticles as clinically translatable, biomaterial-based vehicles for cancer gene therapy.
KW - Gene therapy
KW - Lung cancer
KW - Polyethylene glycol
KW - Polymeric nanoparticle
KW - Surface modification
UR - http://www.scopus.com/inward/record.url?scp=84990967243&partnerID=8YFLogxK
U2 - 10.1016/j.actbio.2016.05.040
DO - 10.1016/j.actbio.2016.05.040
M3 - Article
C2 - 27262740
AN - SCOPUS:84990967243
SN - 1742-7061
VL - 41
SP - 293
EP - 301
JO - Acta Biomaterialia
JF - Acta Biomaterialia
ER -