Synergistic interactions between grafted Hyaluronic ...

1 downloads 0 Views 308KB Size Report
George W. Greene. 3. , Gregory D. Jay. 4 and Jacob. N. Israelachvili* ... CNR-IPCF and Cemif.Cal, Università della Calabria, 31/C. Rende (CS), 87036 Italy;. 3.
Synergistic interactions between grafted Hyaluronic acid and Lubricin provide enhanced wear protection and lubrication Saurabh Das1, Xavier Banquy1, Bruno Zappone2, George W. Greene3, Gregory D. Jay4 and Jacob N. Israelachvili*, 1 1

2

Department of Chemical Engineering, University of California, Santa Barbara, CA 93106;

Consiglio Nazionale delle Ricerche, CNR-IPCF and Cemif.Cal, Università della Calabria, 31/C Rende (CS), 87036 Italy; 3Institute of Frontier Materials, Deakin University, Burwood 3125,

Australia; 4Department of Emergency Medicine and Division of Engineering, Brown University, Providence, Rhode Island

Figure S1. Normal force 𝐹⊥ normalized by R between chemically grafted APTES on the mica surfaces as a function of the mica-mica separation distance, D, with PBS buffer between the

surfaces. The force measurements show that a monolayer of APTES was deposited on the mica surfaces.

Figure S2. “Hard wall” measurements in the SFA to show the growth of the HA film on the mica surface with time, t. The surfaces were rinsed thoroughly in PBS after incubating in HA solution. The error bars indicate the variation in the film thickness of the APTES and HA layer measured at different contact points on the same mica surface.

Figure S3. XPS survey spectra upon (a) APTES grafting on the mica surface, (b) HA grafted to APTES on the mica surface without using EDC, and (c) HA grafted to APTES on the mica surface using EDC chemistry. The arrows indicate the N 1s peak region in the survey scan which was resolved with high resolution XPS scan (Fig. 1).

Figure S4. Top view images of the surfaces and evolution of the FECO fringe pattern during shearing showing wear tracks in the sliding direction of width