Infection-resistant styrenic thermoplastic elastomers that can switch from bactericidal capability to anti-adhesion

Styrenic thermoplastic elastomers (STPEs), particularly for poly(styrene-b-isobutylene-b-styrene) (SIBS), have aroused great interest in the indwelling and implant applications. However, the biomaterial-associated infection is a great challenge for these hydrophobic elastomers. Here, benzyl chloride (BnCl) groups are initially introduced into the SIBS backbone via Friedel-Crafts chemistry, followed by reaction with methyl 3-(dimethylamino) propionate (MAP) to obtain a cationic carboxybetaine ester-modified elastomer. The as-prepared elastomer is able to kill bacteria efficiently, while upon the hydrolysis of carboxybetaine esters into zwitterionic groups, the resultant surface has antifouling performances against proteins, platelets, erythrocytes, and bacteria. This STPE that switches from bactericidal efficacy during storage to the antifouling property in service has great potential in biomedical applications, and is generally applicable to the other styrene-based polymers.