Nanodiamonds and thin diamond films promise new possibilities in biomedicine – from targeted drug delivery to imaging and sensing. Thanks to the exceptional properties of carbon in its diamond form, they are stable, biocompatible, and easily modifiable. The lecture offered an overview of principles, practical examples, and the challenges on the road to their clinical application.
Subheading 1
Nanodiamonds are carbon nanoparticles with an sp3 diamond lattice, typically measuring from a few to tens of nanometers. Their hardness and chemical resistance are complemented by so‑called NV centers (nitrogen vacancies), which give them unique optical and magnetic sensitivity. Compared to other carbon nanomaterials, they exhibit low toxicity, and their surface can be easily functionalized to attach drugs or biomolecules. Similar properties are provided by thin diamond films, which form continuous coatings on the surfaces of medical materials.
Their fluorescence is stable and does not bleach even under prolonged irradiation, which is important for tracking processes in cells. Thanks to their large surface area and tunable chemistry, they are stable in the body and can interact with various biomolecules. These properties facilitate integration into diagnostic, imaging, and therapeutic systems.
Subheading 2
In drug delivery, nanodiamonds are used for their large surface area and the ability to attach functional groups that enable targeted release. They have been used to transport the chemotherapeutic doxorubicin directly to tumors and to deliver nucleic acids with reduced degradation in gene therapy. The result can be higher drug efficacy and fewer side effects thanks to more precise targeting.
In bioimaging and diagnostics, the bright and robust fluorescence of NV centers is key, suitable even for long-term imaging. The same centers enable quantum sensing of physical quantities, for example by measuring relaxation times that change under local “magnetic noise.” This was demonstrated in practice by an experiment with microRNA: manganese ions bound to negatively charged microRNA altered the relaxation of NV centers on the surface of a diamond layer, which made it possible to monitor the presence of molecules in a microfluidic device. After adding a chelating agent, the signal returned to baseline, and sensitivity down to picomolar concentrations was achieved.
Subheading 3
Thin diamond films can be prepared by plasma CVD even on three-dimensional objects, creating durable and biocompatible coatings. By adjusting surface termination (e.g., oxygen, hydrogen) and topography, cell adhesion and growth can be controlled, for example favoring osteoblasts over fibroblasts. In tissue engineering, diamond thus increases the strength of scaffold structures, and in implants it can contribute to antimicrobial properties, durability, and reduced inflammation.
Main challenges include scaling up production with uniform properties, unclear long-term safety profiles including accumulation in the body, and high costs. Future development is heading toward more efficient synthesis and real-time applications – from diagnostics to single-molecule tracking. Prospects include neurotherapies, theranostics, and multifunctional devices combining imaging with intervention. However, transitioning to practice will require standardization, robust testing, and cost reduction.
