Excessive
cell-free DNA (
cfDNA) released by damaged or apoptotic cells can cause
inflammation, impacting the progression of
rheumatoid arthritis (RA).
cfDNA scavengers, such as cationic nanoparticles (NPs), have been demonstrated as an efficient strategy for treating RA. However, most scavengers are limited by unfavorable biocompatibility and poor scavenging efficacy. Herein, by exploiting the favorable biocompatibility, biodegradability and bioadhesion of
polydopamine (P), we modified P with dimethylamino groups to form altered charged DPs to bind negatively charged
cfDNA for RA
therapy. Results showed that DPs endowed with superior binding affinity of
cfDNA and little cytotoxicity, which effectively inhibited
lipopolysaccharide (LPS) stimulated
inflammation in vitro, resulting in the relief of joint swelling, synovial
hyperplasia and cartilage destruction in RA rats. Significantly, DPs with higher DS of bis dimethylamino group exhibited higher positive charge density and stronger
cfDNA binding affinity, leading to excellent RA
therapeutic effect among all of the treated groups, which was even close to normal rats. These finding provides a novel strategy for the treatment of
cfDNA-associated diseases.