Selective Surface PEGylation of UiO-66 Nanoparticles for Enhanced Stability, Cell Uptake, and pH-Responsive Drug Delivery
2017; Elsevier BV; Volume: 2; Issue: 4 Linguagem: Inglês
10.1016/j.chempr.2017.02.005
ISSN2451-9308
AutoresIsabel Abánades Lázaro, Salame Haddad, Sabrina Sacca, Claudia Orellana‐Tavra, David Fairen‐Jimenez, Ross S. Forgan,
Tópico(s)Metal-Organic Frameworks: Synthesis and Applications
ResumoThe high storage capacities and excellent biocompatibilities of metal-organic frameworks (MOFs) have made them emerging candidates as drug-delivery vectors. Incorporation of surface functionality is a route to enhanced properties, and here we report on a surface-modification procedure—click modulation—that controls their size and surface chemistry. The zirconium terephthalate MOF UiO-66 is (1) synthesized as ∼200 nm nanoparticles coated with functionalized modulators, (2) loaded with cargo, and (3) covalently surface modified with poly(ethylene glycol) (PEG) chains through mild bioconjugate reactions. At pH 7.4, the PEG chains endow the MOF with enhanced stability toward phosphates and overcome the "burst release" phenomenon by blocking interaction with the exterior of the nanoparticles, whereas at pH 5.5, stimuli-responsive drug release is achieved. The mode of cellular internalization is also tuned by nanoparticle surface chemistry, such that PEGylated UiO-66 potentially escapes lysosomal degradation through enhanced caveolae-mediated uptake. This makes it a highly promising vector, as demonstrated for dichloroacetic-acid-loaded materials, which exhibit enhanced cytotoxicity. The versatility of the click modulation protocol will allow a wide range of MOFs to be easily surface functionalized for a number of applications.
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