A composite hydrogel of porous gold nanorods and gelatin: Nanoscale structure and rheomechanical properties.

This article investigates the relationship between nanoscale structural characteristics and bulk rheomechanical properties of composite hydrogels made from gelatin—a thermoresponsive natural polymer—and porous gold nanorods (PAuNRs), which are light-responsive and antimicrobial. Using small-angle neutron scattering (SANS), rheological testing, differential scanning calorimetry (DSC), and swelling experiments, the study demonstrates that incorporating PAuNRs into gelatin hydrogels decreases the fractal dimension and elastic moduli, resulting in softer hydrogels with reduced network complexity and thermal stability. These structural and mechanical modulations, tunable by PAuNR concentration and temperature, suggest potential applications in biomedical fields such as tissue engineering, stimuli-responsive drug delivery, and temperature-controlled bioprinting. The findings highlight the role of PAuNRs in disrupting gelatin polymer cross-linking, thereby tailoring hydrogel properties for specific functional uses.