Injectable Thermosensitive Iodine‐Loaded Starch‐g‐poly(N‐isopropylacrylamide) Hydrogel for Cancer Photothermal Therapy and Anti‐Infection

Abstract

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, 1H 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.

Macrophage membrane-coated nanoparticles for the treatment of infectious diseases

“…Also, they can be utilized in diagnostic and therapeutic integration by incorporating bioimaging materials or embedded in hydrogels to form composites for enhanced local neutralization [123]. Fourth, due to their excellent immunomodulatory and drug delivery properties, macrophage membrane-encapsulated nanoparticles are employed in the treatment of not only IDs but also other diseases, such as tumors [124], cardiovascular diseases [125,126], nervous system diseases [127], and chronic wounds [128].…”

Recent Advances in Hydrogel-Based Phototherapy for Tumor Treatment

“…Additionally, the hydrogel system can prevent the leakage of the micelles and enable multiple effective treatments, thereby achieving the elimination of tumors and preventing tumor relapse. Moreover, Fan et al [ 150 ] prepared an iodine-loaded starch-g-PNIPAM polymer that can self-assemble into nanogels and then transform into an injectable thermosensitive hydrogel at body temperature. The hydrogel showed an excellent photothermal effect due to the “iodine-starch” complex’s photothermal effect.…”

Photothermal Hydrogels for Promoting Infected Wound Healing

“…Typically, Wang and co‐workers constructed an injectable thermosensitive hydrogel with a photothermal effect using iodine‐starch complex as PTA, which could be gelatinized in situ after intratumoral injection and heat kill tumors under NIR irradiation (Figure 4b). [ 82 ] However, different from MITA, the iodine‐starch system is not stable under light due to the opening of starch helices caused by thermal motion, thus destroying the coordination structure. By taking advantage of this unstable complex, researchers developed photothermal hydrogels with a safe therapeutic threshold temperature.…”

“…b) Fabrication and characterization of the PNS and PNSI nanogels. Reproduced with permission [82]. Copyright 2022, WILEY-VCH.…”