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EP-4737901-A1 - BIO-MARKED COMPOSITE PARTICLES

EP4737901A1EP 4737901 A1EP4737901 A1EP 4737901A1EP-4737901-A1

Abstract

The present invention relates to bio-marked composite particles.

Inventors

  • DUBERTRET, BENOIT
  • CAO, Edgar
  • FLOCH, Camille

Assignees

  • Nexdot

Dates

Publication Date
20260506
Application Date
20241029

Claims (13)

  1. A bio-marked composite particle (10) comprising • a plurality of fluorescent nanoparticles (102) encapsulated in a matrix (101) comprising aluminium oxide, titanium oxide, zirconium oxide, hafnium oxide, siliocn oxide or mixtures thereof; forming a composite particle and • a plurality of biomolecules (200) anchored at the surface of the matrix (101) of the composite particle (10), said biomolecules (200) comprising an anchor, the anchor comprising at least four histidine residues.
  2. The bio-marked composite particle (10) according to claim 1, wherein the composition of the matrix (101) is Al x Zr y O (I) ; wherein x, and y respectively represent the stoichiometric ratios of Aluminum and Zirconium; x is in the range from 0 to 2/3; y is in the range from 0 to 1/2; and (3/2x+2y)=1.
  3. The bio-marked composite particle (10) according to claim 1 or 2, wherein the composition of the matrix (101) is pure ZrO 2 .
  4. The bio-marked composite particle (10) according to claim 1, wherein the matrix (101) is a metal oxide compound of formula Al x Zr y M z O wherein • x is in the range from 0 to 2/3; • y is in the range from 0 to 1/2; • M represents one or more metal elements selected from the group of Si, Hf, Ge, Sn, or mixtures thereof, and • z is in the range from 0 to 2/5, 0 excluded.
  5. The bio-marked composite particle (10) according to claim 1 to 4, wherein the anchor comprises at least four consecutive histidine residues.
  6. The bio-marked composite particle (10) according to any one of claims 1 to 5, wherein the matrix (101) is obtained by nebulization of a composition in a heated enclosure, said composition comprising • fluorescent nanoparticles (102); and • precursors of aluminium oxide, titanium oxide, zirconium oxide, hafnium oxide, silicon oxide or mixtures thereof.
  7. The bio-marked composite particle (10) according to claim 5, wherein the precursors of aluminium oxide, titanium oxide, zirconium oxide, hafnium oxide or silicon oxide are selected from the group of carboxylates, carbonates, thiolates, alkoxides, oxides, sulfates, phosphates, nitrates, acetates, chlorides, bromides, acetylacetonate or a mixture thereof; preferably the precursors are alkoxides.
  8. The bio-marked composite particle (10) according to any one of claims 1 to 7, wherein the fluorescent nanoparticles (102) are quantum dots.
  9. The bio-marked composite particle (10) according to any one of claims 1 to 7, wherein the fluorescent nanoparticles (102) are quantum nanoplates.
  10. The bio-marked composite particle (10) according to any one of claims 1 to 9, wherein the biomolecules (200) are selected from the group consisting of proteins, nucleic acids, hormones, antigens, antibody, viruses' parts or a mix thereof.
  11. Method for synthetizing a bio-marked composite particle (10) comprising: • Providing composite particles comprising a plurality of fluorescent nanoparticles (102) encapsulated in a matrix (101) comprising aluminium oxide, titanium oxide, zirconium oxide, hafnium oxide, silicon oxide or mixtures thereof; • Providing biomolecules (200) comprising an anchor, the anchor comprising at least four histidine residues; • Mixing the composite particles and the biomolecules (200) in a buffer.
  12. Method according to claim 11, comprising, prior to providing biomolecules comprising an anchor, providing biomolecules and grafting an anchor to said biomolecules, the anchor comprising at least four histidine residues.
  13. Method for detecting antibodies for a biomolecule in a sample, the method comprising: • Sampling a fluid sample of a patient; • Adding the sample to a dispersion comprising the bio-marked composite particles (10) of any of claims 1 to 10 comprising said biomolecule, to obtain a test sample; • Adding a fluorescent probe to the test sample to obtain a probed test sample; • Analyzing the probed test sample through a flow cytometry process.

Description

FIELD OF INVENTION The present invention relates to bio-marked composite particles. More particularly, the present disclosure relates to bio-marked composite particles for detecting antibodies in a sample such as a patient's serum. BACKGROUND OF INVENTION Some diseases may be diagnosed by analyzing the serum of a patient and checking if said serum includes specific antibodies associated with a particular disease. For instance, viral infections may be diagnosed through a blood test. However, each infection must be tested separately through a particular test. Accordingly, when a patient wishes to be tested for several infections, a lot of blood samples and large amounts of independent tests are necessary, which is costly and time consuming. Accordingly, there is a need to improve the known process and to solve, at least partially, the said issues. SUMMARY This invention relates to a bio-marked composite particle comprising a plurality of fluorescent nanoparticles encapsulated in a matrix comprising aluminium oxide, titanium oxide, zirconium oxide, hafnium oxide, silicon oxide or mixtures thereof; forming a composite particle anda plurality of biomolecules anchored at the surface of the matrix of the composite particle, said biomolecules comprising an anchor, the anchor comprising at least four histidine residues. Such bio-marked composite particles emit, thanks to their fluorescent nanoparticles, at a particular wavelength when excited at an excitation wavelength. Thus, the presence of said bio-marked composite particles can be assessed with proper equipment. For instance, it is possible to identify said bio-marked composite particles in a flow cytometry process. Moreover, antibodies may attach the biomolecules anchored to the composite particles. Further, fluorescent probes may attach to said antibodies, themselves attached to the composite particles. Fluorescent probes emit at a particular wavelength and their presence can be assessed with proper equipment. For instance, it is possible to identify fluorescent probes through a flow cytometry process. Accordingly, the particle of the invention may interact with antibodies and fluorescent probes to form a couple that may be identified by two signals: the signal of the nanoparticles, and the signal of the fluorescent probe. Thus, when the two signals are present for a single particle, the formation of the couple is acknowledged. Accordingly, by providing different bio-marked composite particles of the invention associating specific fluorescent nanoparticles to specific biomolecules in a single sample, it is possible to test the presence of a plurality of antibodies in said sample at the same time. In other words, each biomolecule would be associated to a single type of fluorescent nanoparticle that can be selectively identified. Thus, when testing a sample comprising a plurality of antibodies, each antibody would recognize a specific biomolecule. As such, when the antibodies are probed by a fluorescent probe, a couple providing the signal of the specific fluorescent nanoparticles and the signal of the fluorescent probe is formed. Accordingly, considering that each couple of fluorescent nanoparticles/biomolecules are distinctively identified, acknowledging a couple is equivalent to acknowledging the presence of a specific antibody in the sample. Therefore, the bio-marked composite particles of the invention allow testing multiple antibodies in a single test, which is more time efficient, and simpler. Moreover, it is noted that providing an anchor comprising at least four histidine residues enhances the strength of the bounding between the composite particle and the biomolecule. For instance, such an anchor allows biomolecules to remain bound to the composite particle even after at least five washes. In some embodiments, the composition of the matrix is AlxZryO (I) ; wherein x, and y respectively represent the stoichiometric ratios of Aluminum and Zirconium; x is in the range from 0 to 2/3 y is in the range from 0 to 1/2; and (3/2x+2y)=1. Such matrixes are stable and especially resistant to heat and to humidity. Moreover, it has been surprisingly found that embedding fluorescent nanoparticles in a matrix comprising a mixture of alumina and zirconia is especially efficient to prevent fluorescent nanoparticles degradation. Also, such particles are able to disperse in a water-based dispersion. Thus, they are durable even in contact with biological solutions such as serum or urine. In some embodiments, the composition of the matrix is pure ZrO2. Zirconia matrix has shown better binding with the biomolecules comprising anchors comprising histidine residues, compared to other matrixes. Thus, zirconia matrix allows providing more stable bio-marked particles. In some embodiments, the matrix is a metal oxide compound of formula AlxZryMzO, wherein x is in the range from 0 to 2/3, y is in the range from 0 to 1/2, M represents one or more metal elements selected from the gro