Amphiphilic silicones to mitigate lens epithelial cell growth on intraocular lenses

Abstract

Silicone intraocular lenses (IOLs) that resist lens epithelial cell (LEC) growth would greatly improve patient outcomes. Herein, amphiphilic surface modifying additives (SMAs) were incorporated into an IOL-type diphenyl silicone to...

Amphiphilic Silicones for the Facile Dispersion of Carbon Nanotubes and Formation of Soft Skin Electrodes

“…The exception was HDMS 0 , which showed the lowest σ DC (5.11 × 10 –6 S/m), ∼4× lower than that of the control composite (2.10 × 10 –5 S/m). We hypothesize that the absence of a siloxane tether diminishes the compatibility of HDMS 0 with the silicone matrix and led to appreciable phase separation, a result that is consistent with our prior work. − Notably, irrespective of cross-linkability, architecture, or siloxane:PEO, the composites with the highest conductivity were those prepared with PEO-SAs containing siloxane tethers of 12 or 24 repeat units: ( 2-Star [DMS] 12 , 3.01 × 10 –3 S/m > Triblock [DMS] 12 , 2.46 × 10 –3 S/m > 1-Star [DMS] 12 , 2.39 × 10 –3 S/m > HDMS 12 , 1.88 × 10 –3 S/m > HMDS 24 , 1.71 × 10 –3 S/m > 4-Star [DMS] 12 , 1.70 × 10 –3 S/m > 3-Star [DMS] 12 , 6.84 × 10 –4 S/m). Those with longer siloxane tethers ( HDMS 36 , 5.99 × 10 –5 S/m) or shorter siloxane tethers ( 2-Star [DMS] 6 , 2.28 × 10 –4 S/m; 3-Star [DMS] 4 , 3.25 × 10 –4 S/m; 4-Star [DMS] 3 , 1.82 × 10 –4 S/m) showed decreased performance.…”

“…When any of the 12 PEO-SAs were incorporated, all the resulting modified silicone–CNT composites exhibited moduli statistically similar to or lower than that of the neat Sylgard 184. It is hypothesized that this is caused by plasticization effects from the PEO-SAs and their interactions with the CNTs as this effect was not seen in previous work involving Pt-catalyzed silicones …”

“…It is hypothesized that this is caused by plasticization effects from the PEO-SAs and their interactions with the CNTs as this effect was not seen in previous work involving Pt-catalyzed silicones. 45 Electrode Fabrication and Performance. Electrodes were prepared with composites having the highest conductivities (Triblock [DMS] 12 , 1-Star [DMS] 12 , and 2-Star [DMS] 12 ) and worst conductivity (HDMS 0 ) as well as with the unmodified composite (i.e., no PEO-SA).…”

“…Specifically, mixing is performed without added solvents, as well as without extensive mixing protocols or prior surface modification of CNTs. Our prior studies have demonstrated that blending of PEO-SAs in dimethyl silicones induces water-driven surface hydrophilicity and thixotropic rheological properties. − The PEO-SAs were generally composed of an oligo­(dimethyl siloxane) (ODMS m ) tether, a PEO segment (PEO 8 ), and a silane (Si–H) group [e.g., H-Si-ODMS m - block -PEO 8 -OCH 3 ]. In the case of Pt/addition cure silicones, the silane group is cross-linkable with the matrix.…”

Biomedical Silicones: Leveraging Additive Strategies to Propel Modern Utility

“…These were comprised of an oligo­(dimethylsiloxane) (ODMS m ) tether, a PEO headgroup (PEO 8 ), and either a triethoxysilane (TES) group [α-(EtO) 3 Si-(CH 2 ) 2 -ODMS m - block -PEO 8 -OCH 3 ; m = 13 or 30] or a silane (Si–H) group [H-Si-ODMS m - block -PEO 8 -OCH 3 ; m = 13 or 30]. The resulting modified silicones exhibited rapid and substantial water-driven surface hydrophilicity, resulting in broad spectrum biofouling resistance (e.g., proteins, bacteria, platelets, and lens epithelial cells). ,− In contrast, silicones modified with a PEO-silane (i.e., no siloxane tether) did not exhibit such surface and antibiofouling behaviors. Thus, the siloxane tether is hypothesized to improve the miscibility of the amphiphilic SMA in the silicone bulk, improving the ability of PEO segments to migrate to the aqueous interface.…”