Sustainable DNA-polysaccharide hydrogels as recyclable bioplastics

Traditional petrochemical-derived plastics are challenging to recycle and degrade, and the existing (re)process methods are organic solvent-based and/or energy-intensive, resulting in significant environmental contamination and greenhouse gas emissions. This study presents a sustainable bioplastic material characterized by multi-closed-loop recyclability and water (re)processability. The bioplastics are derived from abundant polysaccharide sources of dextran, alginic acid, carboxymethyl cellulose, and DNA of plant and living organism waste. The process involves chemical oxidation of polysaccharides to produce aldehyde-functionalized derivatives, which subsequently form reversible imine covalent bonds with amine groups in DNA. This reaction yields water-processable polysaccharide/DNA crosslinked hydrogels, serving as raw materials for producing sustainable bioplastics. The bioplastic products exhibit (bio)degradability and recyclability, enabling aqueous recovery of the hydrogel constituents through plastic hydrolysis and the natural biodegradability of DNA and polysaccharides. These products demonstrate excellent resistance to organic solvents, self-healing, scalability, and effective processing down to nanometer scales, underscoring their potential for broad and versatile applications. The work provides potential pathways for advancing sustainable and environmentally friendly bioplastic materials.