Although
photothermal therapy (PTT) can effectively eliminate
tumors, the normal tissues near
tumors are inevitably damaged by heat and infected by bacteria, which greatly limits the
therapeutic effect. In this work, an
injectable thermosensitive
hydrogel based on
iodine-loaded
starch-g-
poly(N-isopropylacrylamide) (PNSI) is developed to overcome this problem. FTIR, 1 H NMR, and UV-vis spectra confirm the graft copolymerization of
poly(N-isopropylacrylamide) with
starch and the formation of "
iodine-
starch" complex. Transmission electron microscope images show PNSI
polymer self-assembles into regular spherical
nanogel with a size of ≈50 nm. The concentrated
nanogel dispersion is a
sol at room temperature and transforms to
hydrogel at body temperature. Under NIR
laser irradiation for 10 min, the ΔT of the
nanogel dispersion approachs about 20 °C with excellent thermal stability and high cytotoxicity due to the photothermal effect of the "
iodine-
starch" complex. After intratumor injection, this
injectable hydrogel efficiently inhibites the
tumor growth under 808 nm
laser irradiation. Furthermore, it can also suppress
Staphylococcus aureus infection in the
wound post-PTT due to the release of
iodine, which promotes wound healing. Therefore, this
injectable thermosensitive "
iodine-
starch" composite
hydrogel with advantages of good biocompatible and easy preparation possesses potential application for
tumor photothermal therapy and antibacterial
infection.