Nanodiamond-mediated drug delivery and imaging: challenges and opportunities.

Introduction: The field of nanoparticle-based therapeutic systems is rapidly expanding encompassing a wide variety of practices ranging from detection to diagnosis to treatment. Recently a great potential of nanodiamond (ND) particles as a multimodal imaging/therapy platform has been demonstrated.

Areas Covered: This review describes a unique set of properties of ND particles attractive for drug delivery and imaging applications and highlights the most recent ND-based multimodal imaging/therapy approaches and related biocompatibility studies.

The long-term stability and biocompatibility of fluorescent nanodiamond as an in vivo contrast agent.

Nanocarbon is a promising type of biomaterial for diagnostic and therapeutic applications. Fluorescent nanodiamond (FND) containing nitrogen-vacancy centers as built-in fluorophores is a new addition to the nanocarbon family. Here, we study the long-term stability and biocompatibility of 100-nm FNDs in rats through intraperitoneal injection over 5 months and develop the potential application of this biomaterial for sentinel lymph node mapping in a mouse model.

The exocytosis of fluorescent nanodiamond and its use as a long-term cell tracker.

Fluorescent nanodiamond (FND) has excellent biocompatibility and photostability, making it well suited for long-term labeling and tracking of cancer and stem cells. To prove the concept, the exocytosis of FND particles (size ≈100 nm) from three cell lines--HeLa cervical cancer cells, 3T3-L1 pre-adipocytes, and 489-2.1 multipotent stromal cells--is studied in detail.

The biocompatibility of fluorescent nanodiamonds and their mechanism of cellular uptake.

The labeling of cells with fluorescent nanoparticles is promising for various biomedical applications. The objective of this study is to evaluate the biocompatibility and the mechanism of the cellular uptake of fluorescent nanodiamonds (FNDs) in cancer cells (HeLa) and pre-adipocytes (3T3-L1). With flow cytometry and the use of a battery of metabolic and cytoskeletal inhibitors, we found that the mechanism of the FND uptake in both cells is by energy-dependent clathrin-mediated endocytosis.

Functionalized fluorescent nanodiamonds for biomedical applications.

In recent years, carbon and carbon-based nanomaterials have received increasing attention for applications in life sciences. Nanodiamond (ND) stands out as a unique new substance in these applications because it holds several momentous properties such as good biocompatibility, excellent photostability and facile surface functionalizability. A number of experiments have shown that ND has the highest biocompatibility of all carbon-based nanomaterials including carbon blacks, multiwalled nanotubes, single-walled nanotubes and fullerenes.