With ideal optical properties, semiconducting
polymer quantum dots (SPs) have become a research focus in recent years; a considerable number of studies have been devoted to the application of SPs in non-invasive and biosafety
phototherapy with near-infrared (NIR)
lasers. Nevertheless, the relatively poor stability of SPs in vitro and in vivo remains problematic.
PCPDTBT was chosen to synthesize
photothermal therapy (PTT) and
photodynamic therapy (
PDT) dual-model SPs, considering its low band gap and desirable absorption in the NIR window. For the first time,
cetrimonium bromide was used as a stabilizer to guarantee the in vitro stability of SPs, and as a template to prepare SP hybrid mesoporous
silica nanoparticles (SMs) to achieve long-term stability in vivo. The mesoporous structure of SMs was used as a reservoir for the
hypoxia-activated
prodrug Tirapazamine (TPZ). SMs were decorated with
polyethylene glycol-
folic acid (SMPFs) to specifically target activated macrophages in
rheumatoid arthritis (RA). Upon an 808 nm NIR irradiation, the SMPFs generate intracellular
hyperthermia and excessive
singlet oxygen. Local
hypoxia caused by molecular oxygen consumption simultaneously activates the cytotoxicity of TPZ, which effectively kills activated macrophages and inhibits the progression of
arthritis. This triple PTT-
PDT-chemo synergistic treatment suggests that SMPFs realize the in vivo application of SPs and may be a potential nano-vehicle for RA
therapy with negligible side-toxicity.