Gene Transfection Mediated by Catiomers Requires Free Highly Charged Polymer Chains To Overcome Intracellular Barriers

Autor(es)

Albuquerque, Lindomar J. C. ; de Castro, Carlos E. ; Riske, Karin A. ; Carlan da Silva, Maria C. ; Muraro, Paulo I. R. ; Schmidt, Vanessa ; Giacomelli, Cristiano ; Giacomelli, Fernando C.

• Tipo de documento: Artigo Científico
• Fonte: Biomacromolecules; v. 18, n. 6, p. 1918-1927, JUN 2017.
• Citações Web of Science: 10

Resumo

The prospective use of the block copolymers poly(ethylene oxide)(113)-b-poly{[}2-(diethylamino)ethyl methacrylate](50) (PEO113-b-PDEA(50)) and poly{[}oligo(ethylene glycol)methyl ether methacrylate](70)-b-poly{[}oligo(ethylene glycol)methyl ether methacrylate(10)-co-2-(diethylamino)ethyl methacrylate(47)-co-2-(diisopropylamino) ethyl methacrylate(47)] (POEGMA(70)-b-P(OEGMA(10)-co-DEA(47)-co-DPA(47))) as nonviral gene vectors was evaluated. The polymers are able to properly condense DNA into nanosized particles (R-H approximate to 75 nm), which are marginally cytotoxic and can be uptaken by cells. However, the green fluorescent protein (GFP) expression assays evidenced that DNA delivery is essentially negligible meaning that intracellular trafficking hampers efficient gene release. Subsequently, we demonstrate that cellular uptake and particularly the quantity of GFP-positive cells are substantially enhanced when the block copolymer polyplexes are produced and further supplemented by BPEI chains (branched polyethylenimine). The dynamic light scattering/electrophoretic light scattering/isothermal titration calorimetry data suggest that such a strategy allows the adsorption of BPEI onto the surface of the polyplexes, and this phenomenon is responsible for increasing the size and surface charge of the assemblies. Nevertheless, most of the BPEI chains remain freely diffusing in the systems. The biological assays confirmed that cellular uptake is enhanced in the presence of BPEI and principally, the free highly charged polymer chains play the central role in intracellular trafficking and gene transfection. These investigations pointed out that the transfection efficiency versus cytotoxicity issue can be balanced by a mixture of BPEI and less cytotoxic agents such as for instance the proposed block copolymers. (AU)

• Processo FAPESP: 15/24686-4 - Investigação de efeitos de superfície e presença de coroa protéica no processo de internalização celular de sistemas poliméricos nanoestruturados
• Beneficiário: Carlos Eduardo de Castro
• Linha de fomento: Bolsas no Brasil - Doutorado
• Processo FAPESP: 14/22983-9 - Produção de sistemas supramoleculares nanoestruturados a partir de DNA e copolímeros em bloco catiônicos com potencial aplicação em terapia genética
• Beneficiário: Fernando Carlos Giacomelli
• Linha de fomento: Auxílio à Pesquisa - Regular