Retrievable hydrogel networks with confined microalgae for efficient antibiotic degradation and enhanced stress tolerance

Antibiotic contamination has emerged as a global challenge, increasing antibiotic resistance and threatening human health and ecosystems. Bioremediation using mi-croorganism offers sustainable methods to degrade such pharmaceutical contami-nants. However, these microorganisms exhibit reduced activity under high-stress conditions, and are difficult to recycle and potentially leak into environment as mi-crobial pollutions. Here we report bioprinted retrievable microalgae hydrogel net-works (MHNs) by confining living microalgae in double-network hydrogels, which achieves enhanced antibiotic degradation (>99.3%) and recyclable ability. Particu-larly, coating MHN with tannic acid (MHN@TA) generates a semipermeable mem-brane to prevent the leakage of microalgae (<0.7% for 7 days), ensuring the con-tainment of potential microbial biohazards. The biohybrid system protects the bio-logical activity of microalgae, enabling the superior antibiotic degradation up to 400 mg L-1. Free-standing MHN@TA fencing systems are also manufactured to demon-strate their practical applications. This study provides insights of microal-gae-material interactions in bioremediation and offers design rationales for biohy-brid systems.