title: Fine tuning of the pH-sensitivity of laponite-doxorubicin nanohybrids by polyelectrolyte multilayer coating.
abstract: Despite the wide research done in the field, the development of advanced drug delivery systems with improved drug delivery properties and effective anticancer capability still remains a great challenge. Based on previous work that showed the potentialities of the nanoclay Laponite as a pH-sensitive doxorubicin (Dox) delivery vehicle, herein we report a simple method to modulate its extent of drug release at different pH values. This was achieved by alternate deposition of cationic poly(allylamine) hydrochloride and anionic poly(sodium styrene sulfonate) (PAH/PSS) polyelectrolytes over the surface of Dox-loaded Laponite nanoparticles using the electrostatic layer-by-layer (LbL) self-assembly approach. The successful formation of polyelectrolyte multilayer-coated Dox/Laponite systems was confirmed by Dynamic Light Scattering and zeta potential measurements. Systematic studies were performed to evaluate their drug release profiles and anticancer efficiency. Our results showed that the presence of the polyelectrolyte multilayers improved the sustained release properties of Laponite and allowed a fine tuning of the extension of drug release at neutral and acidic pH values. The cytotoxicity presented by polyelectrolyte multilayer-coated Dox/Laponite systems towards MCF-7 cells was in accordance with the drug delivery profiles. Furthermore, cellular uptake studies revealed that polyelectrolyte multilayer-coated Dox/Laponite nanoparticles can be effectively internalized by cells conducting to Dox accumulation in cell nucleus.
authors.affiliation: School of Textile Science and Engineering, Wuhan Textile University, Wuhan, 430073, People's Republic of China; CQM - Centro de Química da Madeira, MMRG, Universidade da Madeira, Campus da Penteada, 9000-390 Funchal, Portugal. Electronic address: xshili@yahoo.com.
authors.forename: Shili
authors.initials: S
authors.lastname: Xiao
authors.affiliation: CQM - Centro de Química da Madeira, MMRG, Universidade da Madeira, Campus da Penteada, 9000-390 Funchal, Portugal.
authors.forename: Rita
authors.initials: R
authors.lastname: Castro
authors.affiliation: CQM - Centro de Química da Madeira, MMRG, Universidade da Madeira, Campus da Penteada, 9000-390 Funchal, Portugal.
authors.forename: Dina
authors.initials: D
authors.lastname: Maciel
authors.affiliation: CQM - Centro de Química da Madeira, MMRG, Universidade da Madeira, Campus da Penteada, 9000-390 Funchal, Portugal.
authors.forename: Mara
authors.initials: M
authors.lastname: Gonçalves
authors.affiliation: CQM - Centro de Química da Madeira, MMRG, Universidade da Madeira, Campus da Penteada, 9000-390 Funchal, Portugal; College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, People's Republic of China.
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Shi
authors.affiliation: CQM - Centro de Química da Madeira, MMRG, Universidade da Madeira, Campus da Penteada, 9000-390 Funchal, Portugal.
authors.forename: João
authors.initials: J
authors.lastname: Rodrigues
authors.affiliation: CQM - Centro de Química da Madeira, MMRG, Universidade da Madeira, Campus da Penteada, 9000-390 Funchal, Portugal. Electronic address: lenat@uma.pt.
authors.forename: Helena
authors.initials: H
authors.lastname: Tomás
mesh_terms: D002467:Cell Nucleus / Q000378:metabolism; D004317:Doxorubicin / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D061986:MCF-7 Cells; D053758:Nanoparticles / Q000737:chemistry* / Q000378:metabolism; D011108:Polymers / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry*
chemical_list: D011108:Polymers; D017640:Silicates; D004317:Doxorubicin; C524813:laponite
keywords: Anticancer therapy; Doxorubicin; Laponite; Layer-by-layer technique; Nanohybrid; pH-sensitive nanomaterials