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EP-4046659-B1 - MAGNETIC ULTRASOUND CONTRAST AGENT COMPOSITION, MAGNETIC ULTRASOUND CONTRAST AGENT, AND MAGNETIC MICROBUBBLE ULTRASOUND CONTRAST AGENT AND PREPARATION METHOD THEREFOR

EP4046659B1EP 4046659 B1EP4046659 B1EP 4046659B1EP-4046659-B1

Inventors

  • HUANG, SHUO
  • GUO, Wenyu
  • DONG, Feihong
  • ZHANG, JUE

Dates

Publication Date
20260506
Application Date
20210330

Claims (15)

  1. A composition for magnetic ultrasound contrast agent, characterized by comprising a lipid, a surfactant and a magnetic nanoparticle; wherein: the surfactant consists of a surfactant A and a surfactant B, wherein the surfactant A is in a free state, and the surfactant B is modified on the surface of the magnetic nanoparticle; the surfactant A is a nonionic surfactant whose HLB value is greater than 8 and is poloxamer; the surfactant B is citrate and/or citrate ester; and relative to 1mol of the lipid, a content of the surfactant A is 0.1mol to 1mol, a content of the surfactant B is 0.1mol to 1mol, and a content of the magnetic nanoparticle is 0.05mol to 0.5mol.
  2. The composition for magnetic ultrasound contrast agent according to claim 1, characterized in that the surfactant A is a nonionic surfactant whose HLB value is greater than 15; preferably, the surfactant A is a nonionic surfactant whose HLB value is 20 to 35; preferably, the surfactant A is poloxamer and the surfactant B is citrate.
  3. The composition for magnetic ultrasound contrast agent according to claim 1 or 2, characterized in that relative to 1mol of the lipid, the content of the surfactant A is 0.2mol to 0.6mol, the content of the surfactant B is 0.2mol to 0.5mol, and the content of the magnetic nanoparticle is 0.1mol to 0.3mol.
  4. The composition for magnetic ultrasound contrast agent according to any one of claims 1 to 3, characterized in that the molar ratio of the magnetic particle to the surfactant B is 1:0.6 to 1:2.5.
  5. The composition for magnetic ultrasound contrast agent according to any one of claims 1 to 4, characterized by further comprising a drug, and relative to 100 parts by weight of a sum of the lipid, the surfactant and the magnetic nanoparticle, the content of the drug is 1 to 20 parts by weight.
  6. The composition for magnetic ultrasound contrast agent according to any one of claims 1 to 5, characterized in that the lipid consists of sorbitan monostearate and polysorbate 80 in a molar ratio of 1:0.5 to 1:2.
  7. The composition for magnetic ultrasound contrast agent according to any one of claims 1 to 6, characterized in that the magnetic nanoparticle is a superparamagnetic Fe 3 O 4 nanoparticle with a particle size of 3nm to 20nm.
  8. A magnetic ultrasound contrast agent, characterized in that the magnetic ultrasound contrast agent comprises, or is prepared from, the composition for magnetic ultrasound contrast agent according to any one of claims 1 to 7.
  9. A method for preparing a magnetic microbubble ultrasound contrast agent, characterized in that the raw materials comprise the composition for magnetic ultrasound contrast agent according to any one of claims 1 to 7, wherein the method comprises the following steps: (1) making a first contact between the lipid and the surfactant A; (2) mixing the drug with the resulting material obtained by step (1), pumping gases into the mixed resulting material, and processing ultrasonic cavitation to form a first microbubble suspension; (3) processing a treatment for loading a positive charge on the first microbubble suspension to obtain a second microbubble suspension with a positive charge on the surface; (4) making a second contact between the magnetic nanoparticle moified with the surfactant B on the surface and the obtained second microbubble suspension with a positive charge on the surface.
  10. The method according to claim 9, characterized in that the first contact conditions comprise: a temperature of 110°C to 130°C, and a time of 8min to 16min.
  11. The method according to claim 9 or 10, characterized in that in step (2), the mixing is processed at a temperature of 30°C to 50°C.
  12. The method according to any one of claims 9 to 11, characterized in that the ultrasonic cavitation conditions comprise: an ultrasonic power of 8kW to 12kW, and a time of 1min to 8min.
  13. The method according to any one of claims 9 to 12, characterized in that in step (3), the process of the treatment for loading a positive charge comprises: contacting the first microbubble suspension with an aqueous solution of cationic reagent; preferably, the volume ratio of the aqueous solution of cationic reagent and the first microbubble suspension is 0.8:1 to 1.2:1, and the concentration of the cation in the aqueous solution of the cationic reagent is 0.5mg/L to 2mg/L.
  14. The method according to any one of claim 9 to 13, characterized by further comprising: leaving the resulting material, which have contacted with the cationic reagent, to stand for stratification, taking upper layer materials, and washing the upper layer materials with buffer solution.
  15. The method according to any one of claims 9 to 14, characterized in that in step (4), the second contact conditions comprise: processing the material with ultrasonic oscillation with an ultrasonic power of 170 W to 420W, and a time of 15 min to 50min.

Description

FIELD OF THE INVENTION The invention relates to the field of biomedicine, in particular to a composition for magnetic ultrasound contrast agent, a magnetic ultrasound contrast agent including the composition for magnetic ultrasound contrast agent, a preparation method of a magnetic microbubble ultrasound contrast agent, and a magnetic microbubble ultrasound contrast agent prepared by the preparation method. BACKGROUND OF THE INVENTION At present, efficient drugs for treating various cancers are usually insoluble in water, having great side effects, and prone to drug resistance. Study shows that target delivery may solve the above problem. In recent years, many researches have been made by scientists from all over the world in the field of nano-controlled release drug delivery system, such as a tumor-sensitive pH controlled release system, a drug-loaded nanoparticle. Although these nano-drug delivery systems may realize the responsive release of a drug at the tumor site, there are also some problems: such as insufficient of local release amount and low response sensitivity of tumor; especially in a high flow rate area, it is difficult to achieve drug-enriched delivery and visual controlled release. In recent years, Ultrasonic Targeted Microbubble Destruction (UTMD) technology has been widely studied. Because the inertial cavitation occurs upon rupture of a microbubble under a high-energy ultrasonic wave, the microbubble loaded drug blasts at the target area and releases the drug locally, thereby exhibiting the therapeutic effect of targeted drug delivery. Based on the UTMD technology, the microbubble ultrasound contrast agent loaded with a magnetic particle has been studied in the prior art in order to further achieve the drug-enriched delivery and the visual controlled release. However, the stability (cavitation threshold) of the magnetic microbubble ultrasound contrast agent currently used in the UTMD technology is not ideal, and it is hard to meet requirements for in vivo cyclic targeted delivery. Ching-Hsiang FAN et al has disclosed a magnetic microbubble ultrasound contrast agent in a paper of "Ultrasound/Magnetic Targeting with SPIODOX-Microbubble Complex for Image-Guided Drug Delivery in Brain Tumors" (THERANOSTICS, vol. 6, no. 10, 18 June 2016 (2016-06-18), pages 1542-1556, XP055756073,AU ISSN: 1838-7640, DOI: 10.7150/thno.15297), but is silent on the presence of the citric acid-based compound. Therefore, it is of great significance to study a magnetic microbubble ultrasound contrast agent with ideal stability for treating diseases, especially for treating cancers. BRIEF DISCRIPTION OF THE INVENTION The invention is as defined in claims 1 to 15. The object of the present invention is to overcome the problem that the existing magnetic microbubble ultrasound contrast agent has poor stability, and to provide a composition for magnetic ultrasound contrast agent, a magnetic ultrasound contrast agent including the composition for magnetic ultrasound contrast agent, a preparation method of a magnetic microbubble ultrasound contrast agent, and a magnetic microbubble ultrasound contrast agent prepared by the preparation method. The magnetic microbubble ultrasound contrast agent obtained from the composition for magnetic ultrasound contrast agent has higher stability and may meet requirements for in vivo cyclic targeted delivery, thereby achieving the local high-concentration targeted delivery of a medication. The inventors of the present invention have found that by introducing the surfactant with specific component and ratio into a magnetic ultrasound contrast agent, the cavitation threshold of a magnetic microbubble ultrasound contrast agent may be improved effectively. The inventors of the present invention also found that, in a particularly preferred embodiment, by selecting poloxamer and sodium citrate and combining poloxamer and sodium citrate specially, the surface tension of a magnetic microbubble may be changed and the holes on the surface of the microbubble may be filled, so that the cavitation threshold and stability of the magnetic microbubble ultrasound contrast agent are improved further. In order to achieve the above object, a first aspect of the present invention provides a composition for magnetic ultrasound contrast agent, which includes a lipid, a surfactant and a magnetic nanoparticle, wherein the surfactant consists of a surfactant A and a surfactant B, the surfactant A is in a free state, and the surfactant B is in a bonding state and is modified on the surface of the magnetic nanoparticle; the surfactant A is a nonionic surfactant whose HBL value is greater than 8, and the surfactant B is a citric acid-based compound; and relative to 1mol of the lipid, the content of the surfactant A is 0.1mol to 1mol (e.g., 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1), the content of the surfactant B is 0.1mol to 1mol (e.g., 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9 or 1), and the content of the