Glowing Diamond Dust That Stays in the Liver Fluorescent Nanodiamonds as Drug Carriers and Imaging Markers

This application covers fluorescent diamond particles that are given to a patient, carry a drug on their surface, and lodge in an organ, mainly the liver, for days to months. The claims also cover a syringe pre-loaded with the particles, an injectable composition, a method of treating disease, a method of tracking disease by imaging the particles twice, and uses for making medicines. It was filed by Debina Diagnostics, Inc., names Giora Z. Feuerstein and Mark E. Sternberg as inventors, and is a divisional of Australian application 2020296073.

The Problem

The specification’s own statement of the problem is brief. Its background says that nanomaterials are a fast progressing area for diagnostics and therapy, built on combining biological and pharmaceutical entities with physical materials, and then simply that “improved articles and methods are needed”. The description fills in the underlying difficulty: most injected drugs and imaging agents are cleared quickly, so a single dose gives a short window, and following a disease over time means repeated dosing or repeated tests.

The worked example gives a number for how fast clearance can be. Citing earlier pharmacokinetic work, it says blood levels of the particles fall below 10 micrograms per millilitre within 90 minutes of infusion, because the liver takes them up. The specification treats that liver capture as the feature to exploit. It also raises the obvious worry about this approach, which is that leaving a large number of particles in the liver for a long time, possibly indefinitely, could cause harm and could create regulatory hurdles.

What This Invention Does

Claim 1 is an article configured for administration of a therapeutic agent. It has a plurality of fluorescent diamond particles with the therapeutic agent bound to at least some of them, and the article is configured for prolonged residence internal to an organ of a subject. Claim 2 is a separate article, an injection component such as a syringe and a reservoir holding a composition that includes fluorescent diamond particles.

The dependent claims set the particle and residence parameters. The particles have an average diameter from 100 nanometres to 2000 nanometres (claim 3), configured to aggregate within the organ and be captured by it (claims 4 and 5), with aggregates from 1 micron to 100 microns across (claim 6). They have a characteristic near infrared emission (claim 7), the organ is the liver (claim 8), and residence is at least 5 days (claim 9). A pharmaceutical composition of fluorescent diamond particles suspended in an intravenous carrier fluid is claimed in claim 10, with a bound therapeutic agent or a bound diagnostic agent in claims 11 and 12, and residence of up to at least 12 weeks in claim 20.

The method claims are the other half. Claim 21 treats a disease by intravenously administering diamond particles with a therapeutic agent bound to them, configured for prolonged residence in an organ. Claim 23 monitors disease progression by giving the particles, taking a first image of the location, taking a second image after a set period, and measuring a morphological change between the two images relative to the particles, where the change is associated with disease progression. Claim 24 measures this as growth in the area of an internal organ relative to the part of the organ containing particles. Claims 25 to 27 are use claims for making medicines for liver disease and liver cancer, and for monitoring disease progression.

The numbers in the description come from one main example. The particles were fluorescent nanodiamonds containing nitrogen vacancy colour centres, measured at an average diameter of 858 plus or minus 47 nanometres with a zeta potential of minus 56 millivolts. Sprague-Dawley rats were injected through the femoral vein with 60 mg per kg of particles in 2 mL of buffered saline over 2 to 3 minutes. Twelve weeks later, liver sections still showed the particles, scattered across the whole organ and clustered at the boundaries of liver lobules, with some inside hepatocytes and some in the lining of blood vessels. The specification reports no gross or histopathology adverse effects from the particles in the rat liver.

The cell work adds a caution. In cultured human endothelial cells (HUVEC), a high particle dose of 0.1 mg per mL reduced cell number to roughly 60 per cent and cut a measure of esterase activity by about 30 per cent, while a liver cancer cell line (HepG-2) was not affected across the tests. Coating the particles with bovine serum albumin cured aggregation in culture media: particles of 778 nanometres in water grew to 1488 nanometres in buffered saline.

The examples do not show a drug attached to the particles, and they do not show the two image monitoring method of claim 23 being carried out on a diseased animal. They are a distribution and biocompatibility study in healthy rats and cultured cells.

Key Features

• A drug riding on a fluorescent carrier. Claim 1 binds the therapeutic agent to the fluorescent diamond particles, so that the same object both delivers and, through its near infrared glow, can be seen. The description lists many candidate drug types and says binding can use covalent, hydrogen or electrostatic links through functional groups on the particle surface.
• Built to stay put. The article is configured for prolonged residence in an organ. The description gives ranges from days up to the life of the subject, and claims 9 and 20 pick out at least 5 days and up to at least 12 weeks.
• Particle sizing for capture. Claim 3 puts the average diameter between 100 and 2000 nanometres, and claim 6 sets aggregates at 1 to 100 microns. The worked example used particles of about 800 nanometres. Claim 16, on the composition, reads the aggregate upper limit as 10000 microns, which looks like an inconsistency with claim 6 in the printed claims.
• Two images, one measurement. Claim 23 uses the particles as a fixed reference. A first and a second image are compared and the change is measured relative to the particles, such as the growth of an organ against the part that holds particles.
• Syringe and reservoir as an article. Claim 2 covers the delivery hardware pre-loaded with the particle composition, so the claim is not confined to the particles alone.
• Use claims. Claims 25 to 27 claim the manufacture of a medicament for liver disease and liver cancer, and for monitoring disease progression, a form common in applications from the PCT route.

Who Is Behind It

The applicant is Debina Diagnostics, Inc. It has almost no public web presence of its own. Its location, Newtown Square, Pennsylvania, comes from the author affiliations on a 2020 paper in the International Journal of Nanomedicine on near infrared fluorescent nanodiamonds for detecting Ebola virus glycoprotein, on which inventors Giora Feuerstein and Mark Sternberg are both authors alongside Temple University and industry collaborators. Debina is also the assignee of the related earlier family member US 11,085,920, covering nanodiamond particles with a bound species to detect an analyte, filed on 6 September 2017 with priority from 6 September 2016, again naming Feuerstein and Sternberg. The present specification refers to that earlier work as International Patent Application PCT/US2017/050257. No company website, funding record or product was found, so nothing further is said about the company’s size or plans.

On priority, the description states that it claims priority under 35 U.S.C. 119(e) to US provisional application 62/862,802 filed 18 June 2019. The text carries the international publication number WO 2020/257466 and PCT/US2020/038452, which makes it the divisional of an Australian application, 2020296073, that came from that PCT filing. The title page of the Australian document gives the parent number only. The priority country is the United States.

Why It Matters

Treating liver disease is held back by the fact that drugs and contrast agents leave quickly. A particle that parks in the liver and glows in the near infrared offers both a slow release platform and a marker that can be located without a radioactive tracer, which is a different approach from repeated scans. The specification is open about the trade off: the same persistence that makes it useful also makes safety the main question, and it says that effects on immune cells or on organs rich in phagocytes could not be excluded.

The application should be read as an early stage filing. The claims are broad on what is bound to the particle and on what disease is treated, while the evidence is a healthy rat study and cell culture assays. The classification is also unusual, since the only IPC codes assigned, G01T 1/161 and G01T 1/24, relate to radiation measurement and detection rather than pharmaceutical use.

Related Concepts

• Nanodiamond – the particle class at the centre of the claims, which Wikipedia notes has been shown to have drug delivery potential.
• Nitrogen-vacancy center – the lattice defect in diamond that produces the red and near infrared glow used for imaging.
• Drug delivery – the field the therapeutic agent claims belong to.
• Hepatocyte – the main liver cell type in which particles were found in the rat study.
• Fluorescence imaging – the technique used to see the particles in tissue and across repeated images.
• Bovine serum albumin – the protein coating used in the specification to stop the particles clumping in culture media.

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AU 2026202273 was published in the Australian Official Journal of Patents on 16 April 2026 and is open for public inspection. Patent applications represent inventions that are sought to be protected and do not necessarily reflect commercially available products.