99mTc-labeled and functionalised plasmonic nanoparticles for photo-thermal therapy of primary tumours.

Introduction: Photo-thermal therapy (PTT) is an emerging biomedical field involving plasmonic nanoparticles (NPs), which efficiently convert light into heat due to a phenomenon known as Localized Surface Plasmon Resonance (LSPR). The ease of surface functionalization offered, especially by gold NPs (AuNPs), significantly betters their biocompatibility and stability. The radiolabeling of AuNPs with Technetium-99 (^99mTc) allows for their precise spatial localization within the body at any depth and site through nuclear medicine imaging techniques. The combination of radioactive, optical, and thermo-ablative properties makes radiolabelled AuNPs a valid tool in theranostics. This review summarizes the main concepts behind PTT and the most recent clinical applications of plasmonic ^99mTc-labeled NPs in cancer theranostic.

Areas covered: Literature research of the last 20 years was conducted using Scopus and PubMed, including papers concerning technetium-radiolabelled NPs functionalized for cancer PTT.

Expert opinion: AuNPs have been the subject of extensive research for diverse biomedical applications, including cancer diagnostics, therapy, and prevention, as well as drug delivery, sensing and cellular imaging. Despite the limited number of in vivo animal studies, radiolabeling and functionalizing the AuNPs with technetium represents a promising strategy to obtain a specific and efficient theranostic tool for nuclear medicine imaging.