Carbon nanodots (CNDs) are advanced nanomaterials with a size of 2–10 nm and are considered zero-dimensional carbonaceous materials. CNDs have received great attention in the area of cancer theranostics. The majority of review articles have shown the improvement of CNDs for use in cancer therapy and bioimaging applications. However, there is a minimal number of consolidated studies on the currently developed doped CNDs that are used in various ways in cancer therapies. Hence, in this review, we discuss the current developments in different types of heteroatom elements/metal ion-doped CNDs along with their preparations, physicochemical and biological properties, multimodal-imaging, and emerging applications in image-guided photodynamic therapies for cancer.

Regenerative medicine has received potential attention around the globe, with improving cell performances, one of the necessary ideas for the advancements of regenerative medicine. It is crucial to enhance cell performances in the physiological system for drug release studies because the variation in cell environments between in vitro and in vivo develops a loop in drug estimation. On the other hand, tissue engineering is a potential path to integrate cells with scaffold biomaterials and produce growth factors to regenerate organs. Scaffold biomaterials are a prototype for tissue production and perform vital functions in tissue engineering. Silk fibroin is a natural fibrous polymer with significant usage in regenerative medicine because of the growing interest in leftovers for silk biomaterials in tissue engineering. Among various natural biopolymer-based biomaterials, silk fibroin-based biomaterials have attracted significant attention due to their outstanding mechanical properties, biocompatibility, hemocompatibility, and biodegradability for regenerative medicine and scaffold applications. This review article focused on highlighting the recent advancements of 3D printing in silk fibroin scaffold technologies for regenerative medicine and tissue engineering.

With the progress of nanotechnology, the treatment of cancer by photothermal therapy (PTT) and photodynamic therapy (PDT) using theranostic nanomaterials based on iron oxide (Fe3O4) and gold (Au) nanoparticles (NPs) has received much attention in recent years. The Fe3O4 NPs have been used as imaging-guided PTT of cancer due to their high relaxivity, excellent contrast enhancement, and less toxicity. The Au NPs have been widely employed as a contrast agent for CT imaging of different biological systems due to their enhanced X-ray attenuation property. Due to the strong surface plasmon resonance (SPR) absorption intensity in near-infrared (NIR) region, Au NPs have been considered for imaging-guided PTT of cancer. Since the photosensitizer, which plays an important role in PDT of cancer, can be efficiently conjugated with Fe3O4 and Au NPs, these NPs have also been considered for imaging-guided PDT of cancer. It has been found that both Fe3O4 and Au NPs allow passive targeting of tumors through enhanced permeability and retention (EPR) effect to improve the treatment efficacy in PTT and PDT. The present review focuses on the recent developments of Fe3O4 and Au-based NPs as theranostics for imaging-guided PTT and PDT of cancer.