FK506 was completely encapsulated in the spherical and uniform Soluplus-SNPs. Phosphate buffer (50 mM) induced FK506 Soluplus-SNPs to thermosensitive hydrogels. FK506 Soluplus-SNPs hydrogels was sustainable in vitro and long retention in vivo. FK506 Soluplus-SNPs hydrogels significantly treated the AIA rats by local injection.