Next‐Generation Polymer Shells for Inorganic Nanoparticles are Highly Compact, Ultra‐Dense, and Long‐Lasting Cyclic Brushes. Issue 16 (13th March 2017)

• Record Type: Journal Article
• Authors: Morgese, Giulia; Shirmardi Shaghasemi, Behzad; Causin, Valerio; Zenobi‐Wong, Marcy; Ramakrishna, Shivaprakash N.; Reimhult, Erik; Benetti, Edmondo M.
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 16(2017)
• Page Start: 4507
• Page End: 4511
• Publication Date: 2017-03-13
• Subjects: core–shell nanoparticles -- polymer brushes -- polymer topology -- polyoxazolines -- surface functionalization; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201700196
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Cyclic poly‐2‐ethyl‐2‐oxazoline (PEOXA) ligands for superparamagnetic Fe3 O4 nanoparticles (NPs) generate ultra‐dense and highly compact shells, providing enhanced colloidal stability and bio‐inertness in physiological media. When linear brush shells fail in providing colloidal stabilization to NPs, the cyclic ones assure long lasting dispersions. While the thermally induced dehydration of linear PEOXA shells cause irreversible aggregation of the NPs, the collapse and subsequent rehydration of similarly grafted cyclic brushes allow the full recovery of individually dispersed NPs. Although linear ligands are densely grafted onto Fe3 O4 cores, a small plasma protein such as bovine serum albumin (BSA) still physisorbs within their shells. In contrast, the impenetrable entropic shield provided by cyclic brushes efficiently prevents nonspecific interaction with proteins. Abstract : Shields designed to last : When cyclic polymer ligands are grafted onto inorganic nanoparticles (NPs), ultra‐dense and highly compact brush shells are generated. Core‐cyclic shell NPs are significantly more stable than their linear brush‐functionalized counterparts and show full bio‐inertness towards serum proteins.