Temperature-sensitive hydrogels with SiO2-Au nanoshells for controlled drug delivery

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Materials Science

Background:

• Silica-gold (SiO(2)-Au) nanoshells offer tunable optical properties, particularly in the near-infrared (IR) spectrum, enabling light-to-heat conversion.
• Near-IR light penetrates biological tissues with minimal absorption, making it suitable for in-vivo applications.
• Temperature-sensitive hydrogels can undergo phase transitions in response to thermal stimuli.

Purpose of the Study:

• To fabricate and characterize SiO(2)-Au nanoshell-composite hydrogels for photothermal-modulated drug delivery.
• To investigate the light-induced thermal response and drug release kinetics of these composite hydrogels.
• To assess the influence of nanoshell concentration and laser parameters on hydrogel behavior and drug release.

Main Methods:

• Fabrication of SiO(2)-Au nanoshells with tunable optical extinction.
• Integration of SiO(2)-Au nanoshells into N-isopropylacrylamide-co-acrylamide (NIPAAm-co-AAm) temperature-sensitive hydrogels.
• Characterization of hydrogel thermal response to laser irradiation and assessment of drug release profiles for various molecules.

Main Results:

• The composite hydrogels exhibited the optical extinction properties of SiO(2)-Au nanoshells.
• Hydrogels demonstrated reversible collapse at temperatures around 50°C and upon laser irradiation.
• Drug release (methylene blue, insulin, lysozyme) was modulated by laser fluence and nanoshell concentration, showing dependence on molecular weight.

Conclusions:

• SiO(2)-Au nanoshell-composite hydrogels can be effectively utilized for photothermal-controlled drug delivery.
• The drug release rate is tunable by adjusting nanoshell concentration and laser irradiation parameters.
• This system shows potential for targeted and controlled release of therapeutics based on their molecular characteristics.