Mimicking natural biomineralization enabling biodegradable and highly lipophobic alginate hydrogels

Microorganisms can induce biomineralization of inorganic ions to form a lipophobic layer on the surface of cave rocks. Mimicking this, we developed and propose a protocol that produces a highly lipophobic hybrid layer of CaCO₃ nanoparticles on hydrogel surfaces. This lipophobic layer endows hydrogels with an oil contact angle of 162°, causing oil droplets placed on the surface to bead up and roll off immediately. The lipophobic surface effectively resists staining from lipophilic dyes, and does not adhere to double-sided tapes. A lipophobic layer on hydrogel tubes effectively prevents the adhesion of thrombus and axunge during a three-day implantation period in rabbits. The hydrogel tubes, made of biodegradable sodium alginate, can serve as implantable scaffolds, degrading in the body, and avoiding the need for removal surgery. These properties make hydrogel tubes promising for medical devices like absorbable stents and catheters.