Nanodiamonds: Synthesis, properties, toxicities and an update on its effective uses in anticancer drugs deliveries

Nanodiamonds (NDs) are allotropes of carbon nanoparticles that contain tetrahedral SP³ carbon atoms that have various superior properties of optical, chemical stability, and excellent physical properties and ability to form conjugate bonds with so many drugs for pharmaceutical and other medicinal applications. These NDs were synthesized through different techniques from simple detonation in a sealed container using friendly carbon materials to micronization of graphite in water, conversion of diamond micro powder into a glowing crystalline NDs and ultrasonic cavitation of graphite in an organic liquid medium. Exposure of NDs to the alveoli region, macrophages tissue showed low toxicity and when NDs injected after coated with serums to an insect species; Acheta domesticus showed limited toxicity to the insect species. Recent research findings demonstrated its uses in the conjugation and effective delivery of anticancer drugs such as doxorubicins, conjugates of curcumin, usnic acid, 5-fluorouracil and NDs. It was found to increase the solubility and efficacy of 10-hydroxycamptothecin, paclitaxel and also reduces the toxicity of cisplatin anticancer through conjugation. ND-doxorubicin conjugate provided more safety, reduction in myelo suppression, and used to withstand drug-resistant in liver and breast tumors and able to withstand expulsion by cancerous cells in mice. NDs enhance the delivery of nucleic acid in cancer treatment by 70 fold and increase the efficacy of lipofectamine. It was found NDs cause thick inhibition of cancerous cells associated with breast tumor and Hepatocellular carcinoma using curcumin, usnic acid, 5-Fluorouracil, and ND conjugate. It increase penetration of Hydroxyurea anticancer drugs and enhance solubility of paclitaxel when it used as nanocarriers and reduces toxicity of cisplatin in non-cancerous cells and at the same time more injurious to cancerous cells. Nanodiamonds cut the toxicity and increase the potency of anticancer drugs and therefore have a role to play now and in the future in anticancer drug formulations.