Background: Gold nanoparticle (AuNP), owing to its elegant physicochemical properties, has been recently introduced as a promising theranostic nanoparticle. Folic acid is a necessary vitamin for cell proliferation and cancer cells highly require such an essential molecule to be replicated. Accordingly, surface functionalization of AuNP with folic acid may offer great potentials for development of a new nanotechnology based strategy to increase the efficiency of cancer diagnosis and therapy. Here, we review the recent progresses made in design and biomedical applications of various folate-conjugated gold nanoparticles (F-AuNPs). Methods: We performed a structured search of bibliographic databases and then made a comprehensive list of the related papers. The main subjects considered in this review included (1) methods for preparation of F-AuNPs, (2) applications of F-AuNPs in computed tomography (CT), and (3) the use of F-AuNPs in targeted cancer therapy. Results: Ninety-six papers were selected to be reviewed in this article. Accordingly, we explain non-covalent and covalent methods of fabricating various types of F-AuNPs. Particular applications of F-AuNP in cancer diagnosis using CT scan modality are described. Also, applications of F-AuNPs in targeted radiation therapy, chemotherapy, and hyperthermia are elucidated in-depth. In hyperthermia section, we present some extra explanations about F-AuNPs based laser-, radiofrequency-, and ultrasound-hyperthermia methods. Conclusion: This review identifies the important roles of F-AuNPs in current cancer researches which are undertaken worldwide. The findings of this review confirm that F-AuNP is a new theranostic agent which has great potentials for simultaneous cancer therapy and diagnosis.

Ultrasound (US) imaging, due to its capabilities of real-time imaging, portability, low cost and favorable safety, is frequently used as a diagnostic modality for the visualization of different diseases.