Laser-Triggered Degelation Control of Gold Nanoparticle Embedded Peptide Organogels

Abstract

Further understanding of the interactions between nanoparticles (NPs) and biological molecules offers new possibilities in the applications of nanomedicine and nanodiagnostics. The properties of NPs, including size, shape, and surface functionality, play a decisive role in these interactions. Herein, we evaluated the influences of gold NPs (AuNPs) with different sizes (5-60 nm) and shapes (i.e., spherical, rod, and cage) on the self-assembly of diphenylalanine (Phe-Phe) dipeptides. We found that the size of AuNPs smaller than 10 nm did not affect the self-assembly process of Phe-Phe, while bigger AuNPs (>10 nm) caused the formation of starlike peptide morphologies connected to one center. In the case of shape differences, nanorod and nanocage morphologies acted differently than spherical ones and caused the formation of densely packed, networklike dipeptide morphologies. In addition to these experiments, by combining photothermal properties of AuNPs with a Phe-Phe-based organogel having a thermo-responsive property, we demonstrated that the degelation process of AuNPs embedded organogels may be controlled by laser illumination. Complete degelation was achieved in about 10 min. We believe that such control may open the door to new opportunities for a number of applications, such as controlled release of drugs and tissue engineering.

Use of a bis-1,2,3-triazole gelator for the preparation of supramolecular metallogels and stabilization of gold nanoparticles

“…In addition, we confirmed the laser-triggered degelation of a gold NPs containing gel made of click-C 12 -Cyc (c = 40 g L -1 ) in DMF incorporating HAuCl 4 ⋅3H 2 O (molar ratio gelator:Au = 1:1). Finally, in agreement with previous studies, 64 the bulk gel with a 75 T gel of ca. 40 ºC collapsed after 35 min of green laser exposure (λ = 532 nm, 50 mW/cm 2 ) due to the photothermal properties of the Au NPs.…”

Soft Materials Driven by Photothermal Effect and Their Applications

“…Sershen et al have demonstrated independent control of microfluidic valves using nanocomposite hydrogels containing gold nanoparticles . The hydrogel has been formed by poly( N ‐isopropylacrylamide) which exhibits reversible thermal phase changes.…”

Light‐Driven Unidirectional Liquid Motion on Anisotropic Gold Nanorod Arrays

“…[ 34,35 ] Such a conversion provides very rapid and localized heating with high selectivity. Starting from this point, we envisaged that by combining a temperature-sensitive polymeric thin fi lm with a directional AuNR arrays having photothermal properties, we may drive and guide liquid motion at a controlled speed using light illumination ( Figure 4 a).…”