USE OF SMALL MOLECULE BASED ON INDOTRICARBOCYANINE STRUCTURE IN PREPARATION OF MEDICINES FOR TUMOR PHOTOTHERMAL THERAPY

Abstract

The present disclosure belongs to the field of medicines, and particularly relates to property researches of an indotricarbocyanine structure-based small molecule medicine for tumor photothermal therapy. The present disclosure is based on a large-conjugated water-soluble indotricarbocyanine dye compound developed by the applicant, and the compound can be used as a photothermal therapeutic agent, and has a potential development and application prospect. In the present disclosure, the compound is found to be an excellent tumor photothermal therapy medicine, and such use of this compound has not been found and reported at present. Through in-vitro property researches on the photothermal efficiency of this compound, a foundation is provided for clinical application of the indocyanine green-like small molecule photothermal therapeutic agent, and a basis is provided for researches of the small molecule photothermal therapeutic agent.

Claims

1. A method for photothermally treating a tumor, comprising injecting a therapeutically effective amount of a photothermal reagent to a to-be-treated area of a subject, and performing light irradiation on the to-be-treated area of the subject with a laser device at a power density, wherein the photothermal reagent is an indotricarbocyanine structure-based small molecule, and the indotricarbocyanine structure-based small molecule has a structural formula of: ##STR00006## where x is greater than or equal to 1.

2. The method according to claim 1, wherein the power density is 1.0-2.5 W/cm.sup.2.

3. The method according to claim 1, wherein the power density is 1.0 W/cm.sup.2, 1.5 W/cm.sup.2, 2.0 W/cm.sup.2 or 2.5 W/cm.sup.2.

4. The method according to claim 1, wherein a wavelength of the light irradiation is 785 nm.

5. The method according to claim 1, wherein the tumor is selected from the group consisting of liver cancer, retinoblastoma, lung cancer, leukemia, melanoma, pancreatic cancer, breast cancer, prostate cancer, ovarian cancer, bile duct cancer, bladder cancer, bone cancer, cervical cancer, colorectal cancer, esophageal cancer, gastric cancer, kidney cancer, laryngeal cancer, lymphoma, oral cancer, skin cancer, and thyroid cancer.

6. An indotricarbocyanine structure-based small molecule compound for photothermal therapy of a tumor, wherein the indotricarbocyanine structure-based small molecule compound has a structural formula of: ##STR00007## where x is greater than or equal to 1.

7. The small molecule compound according to claim 6, wherein the photothermal therapy of the tumor comprises performing light irradiation on a to-be-treated area of a subject at a power density.

8. The small molecule compound according to claim 7, wherein a wavelength of the light irradiation is 785 nm.

9. The small molecule compound according to claim 6, wherein the tumor is selected from the group consisting of liver cancer, retinoblastoma, lung cancer, leukemia, melanoma, pancreatic cancer, breast cancer, prostate cancer, ovarian cancer, bile duct cancer, bladder cancer, bone cancer, cervical cancer, colorectal cancer, esophageal cancer, gastric cancer, kidney cancer, laryngeal cancer, lymphoma, oral cancer, skin cancer, and thyroid cancer.

10. The method according to claim 2, wherein the power density is 1.0 W/cm.sup.2, 1.5 W/cm.sup.2, 2.0 W/cm.sup.2 or 2.5 W/cm.sup.2.

11. The method according to claim 2, wherein a wavelength of the light irradiation is 785 nm.

12. The method according to claim 3, wherein a wavelength of the light irradiation is 785 nm.

13. The method according to claim 2, wherein the tumor is selected from the group consisting of liver cancer, retinoblastoma, lung cancer, leukemia, melanoma, pancreatic cancer, breast cancer, prostate cancer, ovarian cancer, bile duct cancer, bladder cancer, bone cancer, cervical cancer, colorectal cancer, esophageal cancer, gastric cancer, kidney cancer, laryngeal cancer, lymphoma, oral cancer, skin cancer, and thyroid cancer.

14. The method according to claim 3, wherein the tumor is selected from the group consisting of liver cancer, retinoblastoma, lung cancer, leukemia, melanoma, pancreatic cancer, breast cancer, prostate cancer, ovarian cancer, bile duct cancer, bladder cancer, bone cancer, cervical cancer, colorectal cancer, esophageal cancer, gastric cancer, kidney cancer, laryngeal cancer, lymphoma, oral cancer, skin cancer, and thyroid cancer.

15. The method according to claim 4, wherein the tumor is selected from the group consisting of liver cancer, retinoblastoma, lung cancer, leukemia, melanoma, pancreatic cancer, breast cancer, prostate cancer, ovarian cancer, bile duct cancer, bladder cancer, bone cancer, cervical cancer, colorectal cancer, esophageal cancer, gastric cancer, kidney cancer, laryngeal cancer, lymphoma, oral cancer, skin cancer, and thyroid cancer.

16. The small molecule compound according to claim 7, wherein the power density is 1.0-2.5 W/cm.sup.2.

17. The small molecule compound according to claim 16, wherein the power density is 1.0 W/cm.sup.2, 1.5 W/cm.sup.2, 2.0 W/cm.sup.2 or 2.5 W/cm.sup.2.

18. The small molecule compound according to claim 17, wherein a wavelength of the light irradiation is 785 nm.

19. The small molecule compound according to claim 7, wherein the tumor is selected from the group consisting of liver cancer, retinoblastoma, lung cancer, leukemia, melanoma, pancreatic cancer, breast cancer, prostate cancer, ovarian cancer, bile duct cancer, bladder cancer, bone cancer, cervical cancer, colorectal cancer, esophageal cancer, gastric cancer, kidney cancer, laryngeal cancer, lymphoma, oral cancer, skin cancer, and thyroid cancer.

20. The small molecule compound according to claim 8, wherein the tumor is selected from the group consisting of liver cancer, retinoblastoma, lung cancer, leukemia, melanoma, pancreatic cancer, breast cancer, prostate cancer, ovarian cancer, bile duct cancer, bladder cancer, bone cancer, cervical cancer, colorectal cancer, esophageal cancer, gastric cancer, kidney cancer, laryngeal cancer, lymphoma, oral cancer, skin cancer, and thyroid cancer.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate technical solutions of examples of the present disclosure, accompanying drawings which need to be used in the examples will be introduced briefly below, and it should be understood that the accompanying drawings below merely show some examples of the present disclosure, therefore, they should not be considered as limitation on the scope, and those ordinarily skilled in the art still could obtain other relevant accompanying drawings according to these accompanying drawings, without using any creative efforts.

[0035] FIG. 1 shows ultraviolet absorption spectra of a tumor photothermal therapy medicine ICG-II in the present disclosure and an ICG, of a concentration of 10 PM;

[0036] FIG. 2 shows temperature curves of the tumor photothermal therapy medicine ICG-II in the present disclosure, of the concentration of 10 μM at different power densities;

[0037] FIG. 3 shows temperature change curves of the tumor photothermal therapy medicine ICG-II in the present disclosure, of the concentration of 10 μM at different power densities;

[0038] FIG. 4 shows temperature curves of the tumor photothermal therapy medicine ICG-II in the present disclosure, of different concentrations at a power density of 2.5 W/cm.sup.2;

[0039] FIG. 5 shows temperature change curves of the tumor photothermal therapy medicine ICG-II in the present disclosure, of different concentrations at the power density of 2.5 W/cm.sup.2;

[0040] FIG. 6 shows photothermal effect of the ICG-II of a concentration of 5 μM at the power density of 2.5 W/cm.sup.2, wherein light irradiation is stopped after 8 min;

[0041] FIG. 7 shows a fitted curve of cooling time versus temperature of the ICG-II of the concentration of 5 μM at the power density of 2.5 W/cm.sup.2 after irradiation;

[0042] FIG. 8 shows photothermal effect of the ICG-II of a concentration of 30 μM at the power density of 2.5 W/cm.sup.2, wherein light irradiation is stopped after 8 min;

[0043] FIG. 9 shows a fitted curve of cooling time versus temperature of the ICG-II of the concentration of 30 μM at the power density of 2.5 W/cm.sup.2 after irradiation;

[0044] FIG. 10 shows photothermal effect of the ICG-II of a concentration of 50 μM at the power density of 2.5 W/cm.sup.2, wherein light irradiation is stopped after 10 min;

[0045] FIG. 11 shows a fitted curve of cooling time versus temperature of the ICG-II of the concentration of 50 μM at the power density of 2.5 W/cm.sup.2 after irradiation;

[0046] FIG. 12 shows a cytotoxicity assay of the tumor photothermal therapy medicine ICG-II in a condition without light irradiation; and

[0047] FIG. 13 shows a cytotoxicity assay of the tumor photothermal therapy medicine ICG-II at the power density of 2.5 W/cm.sup.2.

DETAILED DESCRIPTION OF EMBODIMENTS

[0048] Specific steps of the present disclosure are described below through examples, but are not limited by the examples.

[0049] The terms used in the present disclosure, unless otherwise indicated, generally have the meaning commonly understood by those of ordinary skill in the art.

[0050] The present disclosure is further described in detail below in combination with specific examples with reference to data. It should be understood that these examples are only intended to illustrate the present disclosure, but do not limit the scope of the present disclosure in any way.

Example 1

[0051] 1. Preparing an ICG-II solution of a concentration of 10 μM, and measuring temperature changes thereof at different powers; [0052] Weighing a certain amount of ICG-II, dissolving the same in DMSO to prepare a mother liquor of a concentration of 1 mM, subsequently diluting the mother liquor with deionized water to prepare an experimental group solution of a concentration of 10 μM, adjusting, with a 785 nm laser device, a power density thereof to 1.0 W/cm.sup.2, 1.5 W/cm.sup.2, 2.0 W/cm.sup.2, and 2.5 W/cm.sup.2 respectively, measuring the temperature with a thermocouple thermometer under the condition of light irradiation at a time interval of 30 s, and turning off the laser device after the temperature reaching the highest temperature and being stable, and measuring cooling time thereof.
2. Preparing ICG-II of different concentrations, and measuring the temperature changes of the ICG-II of different concentrations at 2.5 W/cm.sup.2; [0053] Weighing a certain amount of ICG-II, dissolving the same in DMSO to prepare a mother liquor of a concentration of 1 mM, subsequently diluting the mother liquor with deionized water to prepare experimental group solutions of four different concentrations 5 μM, 10 μM, 30 μM, and 50 μM, adjusting a power density thereof to 2.5 W/cm.sup.2 with the 785 nm laser device, measuring the temperature with the thermocouple thermometer under the condition of light irradiation at a time interval of 30 s, and turning off the laser device after the temperature reaching the highest temperature and being stable, and measuring cooling time thereof.
3. Calculating photothermal conversion efficiency based on a photothermal conversion efficiency formula and performing comparison. [0054] Based on the photothermal conversion efficiency formula, calculating a photothermal conversion efficiency, wherein the formula is as follows:

[00001]$\mathrm{PTCE}=\frac{\mathrm{hs}\left(T_{\max }-T_{surr}\right)-Q_{Dis}}{I\left(1-10^{-A}\right)}$

[0055] PTCE: photothermal conversion efficiency

[0056] h: heat transfer coefficient

[0057] s: container surface area

[0058] Q.sub.Dis: heat dissipated by solvent and container

[0059] I: scattered power

[0060] A is the absorption at 785 nm

[00002]$hs=\frac{mC}{{\tau }_s}$

[0061] m: mass of solution containing optical substances;

[0062] c: specific heat capacity

[0063] τs: correlation equation calculation

[00003]$t=-{\tau }_s\ln \theta$$\theta =\frac{T-T_{surr}}{T_{\max }-T_{surr}}$$Q_{Dis}=\mathrm{hs}\left(T_{\max }^{\prime }-T_{\mathrm{surr}}^{\prime }\right)$

[0064] T′ refers to the temperature in water

[0065] The results of the measurement of the tumor photothermal therapy medicine ICG-II in the present disclosure, of different concentrations at a power density of 2.5 W/cm.sup.2 are as shown in Table 1.

TABLE-US-00001 TABLE 1 concentra- tion τ.sub.s hs T.sub.max T.sub.surr ΔT Q.sub.Dis PTCE 5 189.84 0.0055 63.8 24.9 38.9 0.0059 0.423 30 138.9 0.0076 80.8 24.7 56.1 0.620 50 124.2 0.0085 84.9 24.9 60 0.754

[0066] Various data symbols in Table 1 represent the following meanings:

[0067] τs is a calculated value of the above photothermal formula

[0068] hs is a calculated value of the above photothermal formula

[0069] T.sub.max is a maximum temperature of thermocouple test within 5 min

[0070] T.sub.sur is an ambient temperature of initial test

[0071] ΔT is temperature difference between the maximum temperature and the initial temperature

[0072] Q.sub.Dis: heat dissipated by solvent and container

[0073] PTCE is the photothermal conversion efficiency

[0074] FIG. 10 shows photothermal effect of the ICG-II of a concentration of 50 μM at the power density of 2.5 W/cm.sup.2, wherein light irradiation is stopped after 10 min.

[0075] FIG. 11 shows a fitted curve of cooling time versus temperature of the ICG-II of a concentration of 50 μM at the power density of 2.5 W/cm.sup.2 after irradiation, wherein a fitting parameter of the fitted curve is is in the photothermal conversion efficiency calculation formula.

[0076] In the present disclosure, under a condition with 785 nm light irradiation at 2.5 W/cm.sup.2, when the probe concentration is 50 μM, the photothermal conversion efficiency thereof is 75%, and the photothermal conversion efficiency is much higher than the photothermal conversion efficiency of indocyanine green ICG in the prior art, indicating that the present disclosure has the potential for efficient photothermal therapy.

Example 2

[0077] 1. The biotoxicity of the tumor therapeutic medicine ICG-II under a condition without light irradiation was studied through an MTT experiment by using HepG2 cancer cells and L02 normal cells.

[0078] HepG2 cell lines and L02 cell lines were selected as experimental cells, and MTT assay (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) was carried out according to standard protocols, so as to verify the biocompatibility of the probe.

[0079] Specifically, cells cultured/grown to an appropriate growth stage were added to a 96-well cell culture plate, and then incubated for 24 hours under a standard cell culture condition. ICG-II of different concentrations (0 μM, 5 μM, 10 μM, 30 μM, 50 μM, respectively) was co-cultured with the cells for 24 hours. Then each well was washed with PBS. 10 mL of MTT solution (of a concentration of 5 mg/ml) was added. After 4 hours of incubation, the culture medium containing the MTT solution was removed, DMSO (150 mL) was added to each well, and the cell culture plate was shaken on a shaker for 15 minutes to completely dissolve crystals. Finally, the absorbance of each well was measured at 490 nm with a plate reader. Since the absorption wavelength of the probe overlaps with the wavelength used in the MTT assay, a blank group will be set, and for the blank group, only the cells and the probe were used for incubation, while the MTT solution was not added, and other conditions were consistent with those of the experimental group. In the experiment, six repetition wells were set for each concentration, and cell viabilities were calculated.

[0080] A histogram was obtained by plotting the above cell viabilities, and was shown in FIG. 12. As shown in FIG. 12, under the condition without light irradiation, the small molecule compound probe ICG-II of the present disclosure shows no cytotoxicity in both HepG2 cancer cells and L02 cells, indicating that the small molecule compound probe ICG-II of the present disclosure has a very low toxic and side effect under the condition without light irradiation.

[0081] 2. Under the condition of light irradiation at 1.5 W/cm.sup.2, the cancer cell line HepG2 was irradiated, and the therapeutic effect of the tumor photothermal medicine was studied through MTT experiment.

[0082] HepG2 cell lines were selected as experimental cells, and MTT assay (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) was carried out according to standard protocols, so as to verify the photothermal treatment effect. Cells cultured/grown to an appropriate growth stage were added to a 96-well cell culture plate, and then incubated for 24 hours under a standard cell culture condition. ICG-II of different concentrations (0 μM, 5 μM, 10 μM, 30 μM, 50 μM, respectively) was co-cultured with the cells for 1 hour. Then irradiation was performed at 1.5 W/cm.sup.2 for 5 min. A blank control group without light irradiation was additionally designed. Then each well was washed with PBS. 10 mL of MTT solution (of a concentration of 5 mg/ml) was added. After 4 hours of incubation, the culture medium containing the MTT solution was removed, DMSO (150 mL) was added to each well, and the cell culture plate was shaken on a shaker for 15 minutes to completely dissolve crystals. Finally, the absorbance of each well was measured at 490 nm with a plate reader. Since the absorption wavelength of the probe overlaps with the wavelength used in the MTT assay, a blank group will be set, and in the blank group, only the cells and the probe were used for incubation, while the MTT solution was not added, and other conditions were consistent with those of the experimental group. In the experiment, six repetition wells were set for each concentration, and cell viabilities were calculated.

[0083] A histogram was obtained by plotting the above cell viabilities, and was shown in FIG. 13. As shown in FIG. 13, under the condition with light irradiation, the small molecule compound probe ICG-II of the present disclosure shows a significant tumor cell killing ability in HepG2 cancer cells, and shows a dose dependency.

[0084] As shown in FIG. 13, when only the small molecule compound ICG-II of the present disclosure of a low concentration of 10 μM is used, the cell viability of cancer cells is reduced to about 25%; and when the small molecule compound ICG-II of the present disclosure of 50 μM is used, the cell viability of cancer cells is further reduced to 18.55%.

[0085] The above results fully prove that the small molecule compound ICG-II of the present disclosure has a powerful anti-tumor activity. The above experimental results fully prove that compared with the prior art, the small molecule compound probe ICG-II based on an indotricarbocyanine structure in the present disclosure has a significantly improved photothermal conversion efficiency, and the photothermal conversion efficiency is much higher than that of the indoletricyanine green ICG in the prior art, indicating that the small molecule compound probe ICG-II based on an indotricarbocyanine structure in the present disclosure has the potential for efficient photothermal therapy.

[0086] In addition, the small molecule compound probe ICG-II based on an indotricarbocyanine structure of the present disclosure shows a significant anti-tumor activity, and can be used as an effective medicine for photothermal therapy of tumors.

[0087] In addition, the small molecule compound ICG-II of the present disclosure shows no cytotoxicity under the condition without light irradiation; however, under the condition with light irradiation, the small molecule compound ICG-II of the present disclosure shows a significant anti-tumor activity. The properties of high activity and low toxic and side effects of the small molecule compound ICG-II of the present disclosure indicate that it will be widely applied in clinical practice.

[0088] The above are merely preferred examples of the present disclosure, rather than limiting the present disclosure, and any amendments, equivalent replacements, improvements and so on, made within the spirit and principle of the present disclosure, should be covered within the scope of protection of the present disclosure.

INDUSTRIAL APPLICABILITY

[0089] The present disclosure finds for the first time the photothermal use of the small molecule compound ICG-II based on an indotricarbocyanine structure. Compared with the indotricarbocyanine photothermal reagents in the prior art, the brand new small molecule compound ICG-II based on an indotricarbocyanine structure provided in the present disclosure has a significantly improved photothermal conversion efficiency, and the photothermal conversion efficiency can be up to 75%.

[0090] The present disclosure provides a small molecule probe based on an indotricarbocyanine structure efficient for tumor photothermal therapy. This small molecule probe has significant anti-tumor activity selective to light irradiation, and shows the properties of high activity and low toxic and side effects.

[0091] The small molecule probe based on an indotricarbocyanine structure provided in the present disclosure has excellent water solubility, has a high photothermal conversion efficiency in a small molecule state, does not need to be prepared into a nano material, avoids the defects of high biotoxicity and poor biological metabolism of nano materials, and has a wide clinical application prospect.