title: Delivery of Splice Switching Oligonucleotides by Amphiphilic Chitosan-Based Nanoparticles.
abstract: Splice switching oligonucleotides (SSOs) are a class of single-stranded antisense oligonucleotides (ssONs) being used as gene therapeutics and demonstrating great therapeutic potential. The availability of biodegradable and biocompatible delivery vectors that could improve delivery efficiencies, reduce dosage, and, in parallel, reduce toxicity concerns could be advantageous for clinical translation. In this work we explored the use of quaternized amphiphilic chitosan-based vectors in nanocomplex formation and delivery of splice switching oligonucleotides (SSO) into cells, while providing insights regarding cellular uptake of such complexes. Results show that the chitosan amphiphilic character is important when dealing with SSOs, greatly improving colloidal stability under serum conditions, as analyzed by dynamic light scattering, and enhancing cellular association. Nanocomplexes were found to follow an endolysosomal route with a long lysosome residence time. Conjugation of a hydrophobic moiety, stearic acid, to quaternized chitosan was a necessary condition to achieve transfection, as an unmodified quaternary chitosan was completely ineffective. We thus demonstrate that amphiphilic quaternized chitosan is a biomaterial that holds promise and warrants further development as a platform for SSO delivery strategies.
authors.affiliation: INEB-Instituto de Engenharia Biomédica, Universidade do Porto (UPorto) , Rua Alfredo Allen, 208, 4200-135 Porto, Portugal.|i3S-Instituto de Investigação e Inovação em Saúde , UPorto, 4200-135 Porto, Portugal.
authors.forename: Pedro M D
authors.initials: PM
authors.lastname: Moreno
authors.affiliation: INEB-Instituto de Engenharia Biomédica, Universidade do Porto (UPorto) , Rua Alfredo Allen, 208, 4200-135 Porto, Portugal.|i3S-Instituto de Investigação e Inovação em Saúde , UPorto, 4200-135 Porto, Portugal.|CeNano2I, Department of Metallurgical and Materials Engineering, UFMG, 31270-901 Belo Horizonte, Brazil.
authors.forename: Joyce C
authors.initials: JC
authors.lastname: Santos
authors.affiliation: INEB-Instituto de Engenharia Biomédica, Universidade do Porto (UPorto) , Rua Alfredo Allen, 208, 4200-135 Porto, Portugal.|i3S-Instituto de Investigação e Inovação em Saúde , UPorto, 4200-135 Porto, Portugal.|Faculdade de Engenharia da UPorto (FEUP), 4200-319 Porto, Portugal.
authors.forename: Carla P
authors.initials: CP
authors.lastname: Gomes
authors.affiliation: INEB-Instituto de Engenharia Biomédica, Universidade do Porto (UPorto) , Rua Alfredo Allen, 208, 4200-135 Porto, Portugal.|i3S-Instituto de Investigação e Inovação em Saúde , UPorto, 4200-135 Porto, Portugal.|Faculdade de Medicina da UPorto (FMUP), 4200-319 Porto, Portugal.
authors.forename: Aida
authors.initials: A
authors.lastname: Varela-Moreira
authors.affiliation: INEB-Instituto de Engenharia Biomédica, Universidade do Porto (UPorto) , Rua Alfredo Allen, 208, 4200-135 Porto, Portugal.|i3S-Instituto de Investigação e Inovação em Saúde , UPorto, 4200-135 Porto, Portugal.
authors.forename: Artur
authors.initials: A
authors.lastname: Costa
authors.affiliation: INEB-Instituto de Engenharia Biomédica, Universidade do Porto (UPorto) , Rua Alfredo Allen, 208, 4200-135 Porto, Portugal.|i3S-Instituto de Investigação e Inovação em Saúde , UPorto, 4200-135 Porto, Portugal.
authors.forename: Victoria
authors.initials: V
authors.lastname: Leiro
authors.affiliation: CeNano2I, Department of Metallurgical and Materials Engineering, UFMG, 31270-901 Belo Horizonte, Brazil.
authors.forename: Herman
authors.initials: H
authors.lastname: Mansur
authors.affiliation: INEB-Instituto de Engenharia Biomédica, Universidade do Porto (UPorto) , Rua Alfredo Allen, 208, 4200-135 Porto, Portugal.|i3S-Instituto de Investigação e Inovação em Saúde , UPorto, 4200-135 Porto, Portugal.|Faculdade de Engenharia da UPorto (FEUP), 4200-319 Porto, Portugal.|Instituto de Ciências Biomédicas Abel Salazar (ICBAS) , UPorto, 4050-313 Porto, Portugal.
authors.forename: Ana P
authors.initials: AP
authors.lastname: Pêgo
mesh_terms: D049109:Cell Proliferation / Q000187:drug effects*; D048271:Chitosan / Q000008:administration & dosage / Q000737:chemistry*; D000067493:Dynamic Light Scattering; D006367:HeLa Cells; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D053758:Nanoparticles / Q000008:administration & dosage / Q000737:chemistry*; D016376:Oligonucleotides, Antisense / Q000737:chemistry / Q000235:genetics / Q000494:pharmacology*; D012326:RNA Splicing
chemical_list: D016376:Oligonucleotides, Antisense; D048271:Chitosan
keywords: chitosan; hydrophobic; nanoparticles; splice switching oligonucleotides; trimethylchitosan