Modification of IONPs with (A) poly(ethylene glycol) saline, (B) poly(vinyl pyrrolidone)-catechol, (C) polylactice acid, (D) polyacrylic acid, (E) poly(lactic-co-glycolic acid), (F) dextran, (G) polyvinyl alcohol, (H) chitosan and (I) polyethyleneimine. (A) Reproduced with permission from 89, copyright 2004. (B) Reproduced with permission from 90, copyright 2013. (C) Reproduced with permission from 91, copyright 2008. (D) Reproduced with permission from 92, copyright 2009. (E) Reproduced with permission from 93, copyright 2012. (F) Reproduced with permission from 94, copyright 2008. (G) Reproduced with permission from 95, copyright 2008. (H) Reproduced with permission from 96, copyright 2010. (I) Reproduced with permission from 97, copyright 2007.