PEGDA/Polydopamine Composite Hydrogel Fibers with Stable Photothermal Performance for Controlled Drug Delivery

Hydrogel fibers (HFs) offer advantages in drug delivery due to their high aspect ratio and biocompatibility. However, existing methods struggle to balance scalable production with structural complexity. Herein, this work reports a microfluidic–post-treatment hybrid strategy that achieves continuous spinning of drug-loaded photothermal HFs using a non-flow-focusing microfluidic chip combined with subsequent polydopamine (PDA) coatings. The PDA@PEGDA composite HFs are constructed with poly(ethylene glycol) diacrylate (PEGDA) as the main scaffold and PDA as the photothermal component. This method produces over 6 m of PEGDA HFs from 2.5 mL of precursor solution. Fluid simulations show that microfluidic chips without flow-focusing structures are better for fiber formation. PDA@PEGDA HFs exhibit high tensile strength (>1 MPa), good spinnability, and photothermal stability under 808 nm near-infrared (NIR) irradiation. NIR-generated localized heat accelerates drug release, achieving >80% cumulative release, approximately 15% higher than that without NIR stimulation. Vancomycin-loaded HFs show >99.9% bactericidal efficacy against Staphylococcus aureus and Escherichia coli . Collectively, this study expands the biomedical applications of hydrogel fibers and provides a scalable platform for fabricating functional HFs.