title: Controlling Properties and Cytotoxicity of Chitosan Nanocapsules by Chemical Grafting.
abstract: The tunability of the properties of chitosan-based carriers opens new ways for the application of drugs with low water-stability or high adverse effects. In this work, the combination of a nanoemulsion with a chitosan hydrogel coating and the following poly (ethylene glycol) (PEG) grafting is proven to be a promising strategy to obtain a flexible and versatile nanocarrier with an improved stability. Thanks to chitosan amino groups, a new easy and reproducible method to obtain nanocapsule grafting with PEG has been developed in this work, allowing a very good control and tunability of the properties of nanocapsule surface. Two different PEG densities of coverage are studied and the nanocapsule systems obtained are characterized at all steps of the optimization in terms of diameter, Z potential and surface charge (amino group analysis). Results obtained are compatible with a conformation of PEG molecules laying adsorbed on nanoparticle surface after covalent linking through their amino terminal moiety. An improvement in nanocapsule stability in physiological medium is observed with the highest PEG coverage density obtained. Cytotoxicity tests also demonstrate that grafting with PEG is an effective strategy to modulate the cytotoxicity of developed nanocapsules. Such results indicate the suitability of chitosan as protective coating for future studies oriented toward drug delivery.
authors.affiliation: Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, Edificio I+D, calle Mariano Esquillor s/n, 50018 Zaragoza, Spain. lauradem@unizar.es.
authors.forename: Laura
authors.initials: L
authors.lastname: De Matteis
authors.affiliation: Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, Edificio I+D, calle Mariano Esquillor s/n, 50018 Zaragoza, Spain. mariaalleva1234@gmail.com.
authors.forename: Maria
authors.initials: M
authors.lastname: Alleva
authors.affiliation: Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, Edificio I+D, calle Mariano Esquillor s/n, 50018 Zaragoza, Spain. inessersev@gmail.com.|Instituto de Ciencia de Materiales de Aragón (ICMA), CSIC-Universidad de Zaragoza, Edificio I+D, calle Mariano Esquillor s/n, 50018 Zaragoza, Spain. inessersev@gmail.com.
authors.forename: Inés
authors.initials: I
authors.lastname: Serrano-Sevilla
authors.affiliation: Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, Edificio I+D, calle Mariano Esquillor s/n, 50018 Zaragoza, Spain. sonia.garcia.embid@gmail.com.
authors.forename: Sonia
authors.initials: S
authors.lastname: García-Embid
authors.affiliation: Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, Edificio I+D, calle Mariano Esquillor s/n, 50018 Zaragoza, Spain. gstepien@unizar.es.
authors.forename: Grazyna
authors.initials: G
authors.lastname: Stepien
authors.affiliation: Istituto di Scienze Applicate e Sistemi Intelligenti "E. Caianiello", Consiglio Nazionale delle Ricerche, Pozzuoli 80078, Italy. m.moros@isasi.cnr.it.
authors.forename: María
authors.initials: M
authors.lastname: Moros
authors.affiliation: Instituto de Ciencia de Materiales de Aragón (ICMA), CSIC-Universidad de Zaragoza, Edificio I+D, calle Mariano Esquillor s/n, 50018 Zaragoza, Spain. jmfuente@unizar.es.
authors.forename: Jesús M
authors.initials: JM
authors.lastname: de la Fuente
mesh_terms: D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D048271:Chitosan / Q000737:chemistry* / Q000633:toxicity*; D002522:Chlorocebus aethiops; D004337:Drug Carriers / Q000737:chemistry / Q000633:toxicity; D016503:Drug Delivery Systems; D004355:Drug Stability; D055664:Electrochemical Techniques; D004655:Emulsions; D006863:Hydrogen-Ion Concentration; D053769:Nanocapsules / Q000737:chemistry* / Q000633:toxicity*; D010316:Particle Size; D011092:Polyethylene Glycols / Q000737:chemistry; D013499:Surface Properties; D013818:Thermogravimetry; D014709:Vero Cells
chemical_list: D004337:Drug Carriers; D004655:Emulsions; D053769:Nanocapsules; D011092:Polyethylene Glycols; D048271:Chitosan
keywords: chitosan; hydrogel; nanocapsules; stability; surface grafting