Effects of Au nanoparticles on thermoresponsive genipin-crosslinked gelatin hydrogels

Abstract

Gold gelatin hydrogel nanocomposites crosslinked with genipin have been prepared, and the effect of citrate capped Au nanoparticles (NPs) as nanofillers in the crosslinking and swelling of gelatin and release of a model drug (methylene blue) from gelatin nanocomposites have been investigated. The citrate-capped Au NPs prevented the crosslinking reaction between the gelatin and genipin and resulted in less crosslinked hydrogels. Although less crosslinked, the Au gelatin nanocomposites swelled less than the unfilled crosslinked gelatin. The gelatin composites were optically active and thermo-sensitive in a temperature range acceptable for living cells. In vitro release studies demonstrated that the irradiation of the composite gels with monochromatic green light (10532 nm, 100 mW) increases the release of the encapsulated methylene blue, most likely due to the photothermal effect of Au nanoparticles. This opens the possibility to explore the application of these nanocomposites as carriers in remotely controlled light-triggered drug release.

Carrageenan–Silica Hybrid Nanoparticles Prepared by a Non‐Emulsion Method

“…Note that the FTIR spectrum of SiCRG shows a new band at approximately 1708 cm –1 that is ascribed to the vibration of hydrogen‐bonded C=O in urethane,16,32–34 which provides evidence for the covalent linkage between κ‐carrageenan and ICPTES through urethane groups. Additional evidence comprises the weak band at approximately 1542 cm –1 due to the N–H bending modes coupled to C–N stretching35 and the band at approximately 970 cm –1 , which is absent in the FTIR spectrum of pure carrageenan and that can be ascribed to the asymmetric Si–O–Et stretching mode 36. The absence of the vibrational band typical of isocyanate groups at approximately 2274 cm –1 (Figure S1, Supporting Information) indicates that all NCO groups have reacted under the conditions employed.…”

Antimicrobial hydrogels: promising materials for medical application

“…83 Au NPs can be designed into different sizes and be functionalized with desired polymers, thus they are realized as biocompatible materials. 84 Au NPs can be attached to the bacterial membrane, which leads to the leakage of bacterial contents or penetration of the outer membrane and the peptidoglycan layer, resulting in bacterial death. 85 However, compared with Ag NPs, studies on antimicrobial Au NP hydrogels alone are rare.…”

Carrageenan-grafted magnetite nanoparticles as recyclable sorbents for dye removal

“…5b) show the characteristic vibrational bands of the polymer at 1230 cm -1 (S-O asymmetric stretch) thus confirming the presence of these polysaccharides at the surface of the nanoparticles. A new band appears in the amide II region at 1538 cm -1 due to the N-H bending mode vibration coupled to stretching C-N vibrations (Bruce and Sen 2005;Daniel-da-Silva et al 2013b). Also a weak band appears at 1260 cm -1 in the amide III region, also assigned to the C-N stretching and N-H bending (Pelton and McLean 2000).…”