Nanodiamonds Doped with Manganese for Applications in Magnetic Resonance Imaging

Srinivasu Kunuku; Bo-Rong Lin; Chien-Hsu Chen; Chun-Hsiang Chang; Tzung-Yuang Chen; Tung-Yuan Hsiao; Hung-Kai Yu; Yu-Jen Chang; Li-Chuan Liao; Fang-Hsin Chen; Robert Bogdanowicz; Huan Niu

doi:10.1021/acsomega.2c08043

Nanodiamonds Doped with Manganese for Applications in Magnetic Resonance Imaging

ACS Omega. 2023 Jan 22;8(4):4398-4409. doi: 10.1021/acsomega.2c08043. eCollection 2023 Jan 31.

Authors

Affiliations

¹ Department of Metrology and Optoelectronics, Faculty of Electronics, Telecommunications and Informatics, Gdańsk University of Technology, Gdańsk 80233, Poland.
² Accelerator Laboratory, Nuclear Science and Technology Development Center, National Tsing Hua University, Hsinchu 300044, Taiwan.
³ Department of Biomedical Engineering and Environmental Sciences, National Tsing Hua University, Hsinchu 300044, Taiwan.
⁴ Health Physics Division, Nuclear Science and Technology Development Center, National Tsing Hua University, Hsinchu 300044, Taiwan.
⁵ Bioresource Collection and Research Center, Food Industry Research and Development Institute, Hsinchu 300193, Taiwan.
⁶ Institute of Nuclear Engineering and Science, National Tsing Hua University, Hsinchu 300044, Taiwan.

Abstract

Nanodiamonds (NDs) are emerging with great potential in biomedical applications like biomarking through fluorescence and magnetic resonance imaging (MRI), targeted drug delivery, and cancer therapy. The magnetic and optical properties of NDs could be tuned by selective doping. Therefore, we report multifunctional manganese-incorporated NDs (Mn-NDs) fabricated by Mn ion implantation. The fluorescent properties of Mn-NDs were tuned by inducing the defects by ion implantation and enhancing the residual nitrogen vacancy density achieved by a two-step annealing process. The cytotoxicity of Mn-NDs was investigated using NCTC clone 929 cells, and the results revealed no cytotoxicity effect. Mn-NDs have demonstrated dual mode contrast enhancement for both T ₁- and T ₂-weighted in vitro MR imaging. Furthermore, Mn-NDs have illustrated a significant increase in longitudinal relaxivity (fivefold) and transversal relaxivity (17-fold) compared to the as-received NDs. Mn-NDs are employed to investigate their ability for in vivo MR imaging by intraperitoneal (ip) injection of Mn-NDs into mice with liver tumors. After 2.5 h of ip injection, the enhancement of contrast in T ₁- and T ₂-weighted images has been observed via the accumulation of Mn-NDs in liver tumors of mice. Therefore, Mn-NDs have great potential for in vivo imaging by MR imaging in cancer therapy.