Nanomaterials are endowed with unique features and essential properties suitable for employing in the field of nanomedicine. The nanomaterials can be classified as 0D, 1D, 2D, and 3D based on their dimensions. The nanomaterials can be malleable and ductile and they can be drawn into wires and sheets. Examples of nanomaterials are quantum dots (0D), nanorods, nanowires (1D), nanosheets (2D), and nanocubes (3D). These nanomaterials can be synthesized using top-down and bottom-up approaches. The achievements of 0D and 1D nanomaterials are used to detect trace heavy metal (e.g., Pb²⁺) and have higher sensitivity with the order of five as compared to conventional sensors. The achievements of 2D and 3D nanomaterials are used as diagnostic and therapeutic agents with multifunctional ability in imaging systems such as PET, SPECT, etc. These imaging modalities can be used to track the drug in living tissues. This review comprises the state-of-the-art of the different dimensions of the nanomaterials employed in theranostics. The nanomaterials with different dimensions have unique physicochemical properties that can be utilized for therapy and diagnosis. The multifunctional ability of the nanomaterials can have a distinct advantage that is used in the field of theranostics. Different dimensions of the nanomaterials would have more scope in the field of nanomedicine.

Micro-RNAs (miRNA) are short non-coding sequences involved in the biological regulatory process. The miRNAs show a unique expression in diseases, resulting in pathogenesis. Identifying the novel compounds is interesting during this process. The miRNA is a biomarker that helps to detect cancer at an early stage through pathogenesis. Azobenzene and pyrazole are novel compounds, having a cytotoxic effect on cancer cells. These novel compounds are molecular probes used in breast cancer therapy. The viral-based systems have few limitations, such as toxicity and immunogenicity. Therefore, the non-viral based lipoplex and polyplex systems are attractive due to no size limitations for the transfection of micro RNAs. The conventional drug delivery systems have a large size and low drug efficacy at the target site. The nanoparticles prepared by nanoprecipitation methods are attractive in cancer therapy. Thus, the miRNA acts as a powerful tool and identifies the drug target in cancer therapy.