The cyclic polymer topology strongly alters the interfacial, physico-chemical properties of polymer brushes, when compared to the linear counterparts. In this study, we especially concentrated on poly-2-ethyl-2-oxazoline (PEOXA) cyclic and linear grafts assembled on titanium oxide surfaces by the "grafting-to" technique. The smaller hydrodynamic radius of ring PEOXAs favors the formation of denser brushes with respect to linear analogs. Denser and more compact cyclic brushes generate a steric barrier that surpasses the typical entropic shield by a linear brush. This phenomenon, translates into an improved resistance towards biological contamination from different protein mixtures. Moreover, the enhancement of steric stabilization coupled to the intrinsic absence of chain ends by cyclic brushes, produce surfaces displaying a super-lubricating character when they are sheared against each other. All these topological effects pave the way for the application of cyclic brushes for surface functionalization, enabling the modulation of physico-chemical properties that could be just marginally tuned by applying linear grafts.
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http://dx.doi.org/10.1002/anie.201607309 | DOI Listing |
Biomacromolecules
December 2024
Laboratory for Macromolecular and Organic Chemistry, Department of Chemical Sciences, University of Padova, Padova 35131, Italy.
Cyclic poly(2-methyl-2-oxazine) (-PMOZI) brush shells on Au nanoparticles (NPs) exhibit enhanced stealth properties toward serum and different cell lines compared to their linear PMOZI (-PMOZI) counterparts. While selectively recruiting immunoglobulins, -PMOZI shells reduce overall human serum (HS) protein binding and alter the processing of complement factor 3 (C3) compared to chemically identical linear shells. Polymer cyclization significantly decreases NP uptake by nonphagocytic cells and macrophages in both complement-deficient fetal bovine serum (FBS) and complement-expressing HS, indicating ineffective functional opsonization.
View Article and Find Full Text PDFChem Sci
October 2024
Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, School of Chemistry, Sun Yat-sen University Guangzhou 510006 P. R. China
Sensors (Basel)
July 2024
College of Information Science and Technology, Nanjing Forestry University, Nanjing 210037, China.
Skeleton-based action recognition, renowned for its computational efficiency and indifference to lighting variations, has become a focal point in the realm of motion analysis. However, most current methods typically only extract global skeleton features, overlooking the potential semantic relationships among various partial limb motions. For instance, the subtle differences between actions such as "brush teeth" and "brush hair" are mainly distinguished by specific elements.
View Article and Find Full Text PDFJ Endod
September 2024
Department of Endodontic, São Leopoldo Mandic School of Dentistry, Campinas, SãP Paulo, Brazil.
Introduction: This study aimed to evaluate the dynamic cyclic fatigue resistance of Reciproc Blue files subjected to brushing motion.
Methods: Twenty Reciproc Blue files (R25, VDW, Munich, Germany) were employed for chemical-mechanical preparation in root canals of 3D printed replicas of mandibular molars. The instruments were divided into two groups (n = 10): Group brushing motion, instrumentation with brushing motions; Group without brushing motion , instrumentation without brushing motions.
J Hosp Infect
August 2024
Medical Affairs, Nanosonics Ltd, Sydney, Australia. Electronic address:
Introduction: Biofilm contributes significantly to bacterial persistence in endoscope channels. Enhanced cleaning methods capable of removing biofilm from all endoscope channels are required to decrease infection risk to patients. This head-to-head study compared cyclic build-up biofilm removal of an automated endoscope channel cleaner (AECC) with standard manual cleaning according to instructions for use (IFU) in polytetrafluorethylene channels.
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