Photodynamic therapy (
PDT) has attracted much attention as a strategy for
tumor therapy. However, the insolubility and poor
tumor-targeting ability of most
photosensitizers (PSs) hinder
PDT from further development. Therefore, it is necessary to explore new carriers with good water solubility and biocompatibility to deliver PSs to
tumors.
Melanin nanoparticles are novel biomimetic nanocarriers with excellent biocompatibility, loading capacity,
photothermal therapy (PTT) and magnetic resonance (MR)/photoacoustic (PA) imaging properties. Here we designed
polydopamine melanin nanoparticles (PDMNs) as a delivery platform for the
photosensitizer Chlorin e6 (PDMN-Ce6) and realized its application as a
theranostic agent for
tumor therapy. The PDMN-Ce6 exhibited excellent biocompatibility, good water solubility and high loading capability (35.2 wt%) for Ce6. Compared with the free Ce6, PDMN-Ce6 showed higher cellular internalization and superior synergistic
phototherapy effects in an in vitro study. An in vivo study indicated that the accumulation of PDMN-Ce6 at
tumor sites was 2.8-fold higher than that of free Ce6 at 24 h post-injection, which was beneficial for MR/PA imaging. Moreover, the synergetic
therapy significantly inhibited
tumor growth, causing
tumor necrosis and
tumor angiogenesis suppression. These results suggest that our biomimetic and biocompatible platform could improve the delivery of Ce6 to
tumors and realize multimodal imaging-guided
tumor synergetic
phototherapy.