Degradable tracing punctum plug as well as preparation method and application thereof

Abstract

The invention belongs to the field of medical instruments, and particularly relates to a degradable tracing punctum plug and a preparation method and application thereof. The preparation method comprises the steps that polylactic acid and a coloring agent are mixed to obtain colored polylactic acid; mixing the colored polylactic acid with an alkaline inorganic filler to obtain a mixture; carrying out segmented temperature control injection molding treatment on the mixture to obtain an injection molding product; the injection molding product is treated for 5-120 s under the conditions of 25-40 DEG C and 20-50 Mpa, and a punctal plug precursor is obtained; and carrying out heat preservation treatment on the punctum plug precursor to obtain the degradable tracing punctum plug. According to the preparation method, raw materials are easy to obtain, the process is simple, the alkaline inorganic filler regulates and controls the degradation rate and inhibits inflammation caused by an acidic product generated by degradation of polylactic acid in the use process of the punctal plug, intraoperative visual tracing and positioning are achieved through the coloring agent, and the crystallinity of the material is improved through the low-temperature pressure maintaining process; the problems of brittle fracture and uncontrollable degradation rate of the degradable punctum plug are solved, and the degradable punctum plug has a wide prospect in minimally invasive treatment of xerophthalmia.

Description

Technical Field

[0001] This invention belongs to the field of medical devices, specifically relating to a biodegradable tracer tear punctum plug, its preparation method, and its application. Background Technology

[0002] In recent years, with the development of industry and the widespread use of electronic terminal products, the incidence of dry eye has been increasing year by year, and it has now become a global health problem. At present, there is still no cure for dry eye. The main treatment strategies include replenishing the aqueous components of the ocular surface, reducing the loss of water from the ocular surface, anti-inflammatory treatment of the ocular surface, and punctal plugging.

[0003] Existing punctal plugs mainly include two types: non-degradable and biodegradable. Non-degradable punctal plugs are usually made of silicone rubber; however, permanent punctal plugging can lead to or increase the risk of canaliculitis, dacryocystitis, and lacrimal duct granuloma. Removal is also difficult and risky, requiring invasive surgeries such as canaliculotomy or dacryocystorhinostomy to remove the plug. Biodegradable punctal plugs mainly include polydioxanone and hydrogel plugs. However, the degradation time of these two types is uncontrollable, and they cannot be observed without contrast translucency, making it easy to lose the target material and hindering observation of the plug.

[0004] Therefore, there is an urgent need in the field for a biodegradable punctal plug that can be visualized and has adjustable degradation time to treat dry eye syndrome in order to solve the existing technical problems. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the present invention provides a biodegradable tracer punctum plug, its preparation method and application, aiming to solve the problems of instability, poor degradability control and poor visualization of existing punctum plugs.

[0006] To achieve the first objective of the invention, the present invention adopts the following technical solution:

[0007] A biodegradable tracer tear punctum plug, characterized in that it comprises the following components by weight percentage:

[0008] Colorant 0-1 wt%;

[0009] Alkaline inorganic fillers, 0–10 wt%;

[0010] The weight percentage of the colorant and alkaline inorganic filler is not 0;

[0011] The remaining material is polylactic acid, and the total weight percentage of all components is 100 wt%.

[0012] In one embodiment, the biodegradable tracer tear punctum plug comprises the following components by weight percentage:

[0013] Colorant 0.01–0.05 wt%;

[0014] Alkaline inorganic filler 0.5–5 wt%;

[0015] The remaining material is polylactic acid, and the total weight percentage of all components is 100 wt%.

[0016] In one embodiment, the alkaline inorganic filler has a weight percentage of 1-2 wt%.

[0017] In one embodiment, the alkaline inorganic filler includes at least one of hydroxyapatite and β-tricalcium phosphate.

[0018] In one embodiment, the alkaline inorganic filler is hydroxyapatite.

[0019] In one embodiment, the colorant includes at least one of D&C Violet 2, D&C Green 6, and [phthalocyanine (2-)]copper.

[0020] In one embodiment, the biodegradable tracer tear punctum plug has a diameter of 0.1–1 mm, a length of 0.5–5 mm, and a cylindrical structure.

[0021] A second objective of this invention is to provide a method for preparing the above-mentioned biodegradable tracer tear punctum plug, comprising the following steps:

[0022] Colored polylactic acid is obtained by mixing polylactic acid with a coloring agent;

[0023] The colored polylactic acid is mixed with an alkaline inorganic filler to obtain a mixture;

[0024] The mixture is subjected to injection molding to obtain an injection molded product;

[0025] The injection-molded product was treated at 25–40°C and 20–50 MPa for 5–120 s to obtain a tear spot plug precursor.

[0026] The teardrop plug precursor was heat-insulated to obtain a biodegradable tracer teardrop plug.

[0027] In one embodiment, the polylactic acid needs to be dried at a temperature of 50–70°C for 1–3 hours.

[0028] In one embodiment, the injection molding includes segmented temperature-controlled injection molding, wherein the conditions for the segmented temperature-controlled injection molding include:

[0029] The hopper preheating temperature is 160-180℃;

[0030] The heating end temperature is 170–200℃;

[0031] The injection end temperature is 160-180℃.

[0032] In one embodiment, the temperature of the tear duct plug precursor is kept warm at 40–80°C for 0.5–1.5 hours.

[0033] A third object of the present invention is to provide a medical device for treating dry eye syndrome, the medical device comprising any one of the biodegradable tracer punctal plugs.

[0034] The beneficial effects of this invention are:

[0035] (1) The preparation method of the biodegradable tracer tear punctum plug provided by the present invention is simple, the required raw materials are readily available and inexpensive, and the preparation method does not involve chemical reactions or use toxic and harmful chemical reagents, and will not produce substances harmful to the human body.

[0036] (2) The preparation method of the biodegradable tracer teardrop plug provided by the present invention uses a low temperature holding pressure process to treat the injection molded product, which can improve the crystallinity of the teardrop plug, making it more stable and avoiding brittle fracture of the biodegradable teardrop plug.

[0037] (3) The preparation method of the biodegradable tracer punctum plug provided by the present invention gives the punctum plug obvious visualization function. Doctors can easily identify the location and status of the punctum plug during clinical surgery, which helps to operate accurately and improve the success rate of surgery. It has significant clinical significance.

[0038] (4) The tear punctum plug obtained by the present invention can adjust the degradation time of the tear punctum plug by adjusting the type and amount of alkaline inorganic filler, so as to match the treatment cycle of the patient. It can maintain the treatment effect for a long time and will not remain in the body for a long time. Combined with the low temperature pressure holding process, it solves the problems of brittle fracture and uncontrollable degradation rate of degradable tear punctum plugs, and has broad prospects in the minimally invasive treatment of dry eye syndrome. Attached Figure Description

[0039] Figure 1 The tear punctum plugs prepared in Examples 1, 2 and Comparative Example 1 of this invention are shown under a 10x magnifying glass.

[0040] Figure 2 The image shows the differential scanning calorimetry (DSC) test curves of the tear spot plugs prepared in Comparative Examples 1 and 2 of this invention.

[0041] Figure 3 The degradation weight loss curves of the tear punctum plugs prepared in Comparative Example 1 and Examples 1-4 of this invention are shown.

[0042] Figure 4 The pH curves for the degradation of tear spot plugs prepared in Comparative Example 1 and Examples 1-4 of this invention are shown.

[0043] Figure 5 The results are the in vitro cell compatibility test results of the tear punctum plugs prepared in Comparative Example 1 and Examples 1-4 of this invention. Detailed Implementation

[0044] To make the objectives, technical solutions, and effects of this invention clearer and more explicit, the invention is further described in detail below. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0045] The terms “comprising,” “including,” “having,” “containing,” or any other variations thereof, as used herein, are intended to cover non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not limited to those elements and may also include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0046] "Optional" or "any one" means that the matter or event described thereafter may or may not occur, and the description includes both the possibility that the event will occur and the possibility that the event will not occur.

[0047] The indefinite articles “a” and “an” preceding an element or component of this invention do not impose any limitation on the quantity (i.e., number of times) of the element or component. Therefore, “an” or “a” should be interpreted as including one or at least one, and the singular form of an element or component also includes the plural form, unless the quantity clearly refers only to the singular form.

[0048] The terms "one embodiment," "some embodiments," "exemplary," "specific example," or "some examples," etc., used in this invention refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this document, the illustrative expressions of the above terms are not necessarily directed at the same embodiment or example.

[0049] The numerical range described in this invention includes not only the point values ​​listed in the embodiments, but also any point values ​​not listed within the numerical range described in this invention. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0050] In the following examples, unless otherwise specified, all reagents and consumables were purchased from conventional reagent manufacturers in the field.

[0051] This embodiment provides a method for preparing a biodegradable tracer tear punctum plug, comprising the following steps:

[0052] S1. Polylactic acid is mixed with a colorant to obtain colored polylactic acid;

[0053] S2. Mix colored polylactic acid with alkaline inorganic filler to obtain a mixture;

[0054] S3. The mixture is subjected to segmented temperature-controlled injection molding to obtain the injection molded product;

[0055] S4. Treat the injection-molded product at 25-40℃ and 20-50 MPa for 5-120 seconds to obtain the tear spot plug precursor;

[0056] S5. The precursor of the tear punctum plug is heat-insulated to obtain a biodegradable tracer tear punctum plug.

[0057] In some specific embodiments, the polylactic acid used in step S1 needs to be dried at a temperature of 50–70°C for 1–3 hours.

[0058] In some specific implementations, as an example, the drying temperature of polylactic acid can be 50°C, 55°C, 60°C, 65°C, or 70°C, as long as the drying temperature of polylactic acid is within the range of 50°C to 70°C.

[0059] In some specific implementations, for example, the drying time of polylactic acid can be 1 hour, 1.5 hours, 2 hours, 2.5 hours, or 3 hours, as long as the drying time of polylactic acid is within the range of 1 to 3 hours.

[0060] In some specific implementations, step S3, which involves segmented temperature-controlled injection molding of the mixture, is performed in an injection molding machine, which includes a hopper, a heating end, and an injection end.

[0061] In some specific implementations, for example, the preheating temperature of the hopper can be 160°C, 165°C, 170°C, 175°C, or 180°C, as long as the preheating temperature of the hopper is within the range of 160°C to 180°C.

[0062] In some specific implementations, for example, the temperature of the heating end can be 170°C, 175°C, 180°C, 185°C, 190°C, 195°C, or 200°C, as long as the temperature of the heating end is within the range of 170°C to 200°C.

[0063] In some specific implementations, for example, the temperature of the injection end can be 160°C, 165°C, 170°C, 175°C, or 180°C, as long as the temperature of the injection end is within the range of 160°C to 180°C.

[0064] In some specific embodiments, step S4 requires subjecting the obtained injection-molded product to a cryogenic holding pressure treatment. The cryogenic holding pressure is 25–40°C, the cryogenic holding pressure is 20–50 MPa, and the cryogenic holding time is 5–120 s. This cryogenic holding pressure treatment can improve the crystallinity of the final teardrop plug, enhance its stability, and prevent brittle fracture of the biodegradable teardrop plug.

[0065] In some specific implementations, for example, the cryogenic pressure holding temperature can be 25°C, 30°C, 35°C, or 40°C, as long as the cryogenic pressure holding temperature is within the range of 25°C to 40°C.

[0066] In some specific implementations, for example, the pressure for cryogenic pressure holding can be 20MPa, 25MPa, 30MPa, 35MPa, 40MPa, 45MPa, or 50MPa, as long as the cryogenic pressure holding pressure is within the range of 20 to 50MPa.

[0067] In some specific implementations, the cryogenic pressure holding time can be 5s, 10s, 20s, 30s, 45s, 60s, 75s, 90s, 100s, or 120s, as long as the cryogenic pressure holding time is within the range of 5 to 120s.

[0068] In some specific implementations, cryogenic pressure holding is performed by placing the injection-molded product in a corresponding mold. The mold can be adjusted according to the shape of the teardrop plug product. This embodiment does not impose any other limitations on the mold.

[0069] In some specific implementations, step S4 also requires heat preservation treatment of the obtained tear spot plug precursor.

[0070] In some specific implementations, the insulation temperature can be 40℃, 45℃, 50℃, 55℃, 60℃, 65℃, 70℃, 75℃, or 80℃, as long as the insulation temperature of the tear spot plug precursor is within the range of 40 to 80℃.

[0071] In some specific implementations, the heat preservation time of the tear punctum plug precursor can be 0.5h, 1h, or 1.5h, as long as the heat preservation time is within the range of 0.5 to 1.5h.

[0072] In one specific embodiment, the present invention provides a biodegradable tracer punctum plug, which comprises the following components by weight percentage:

[0073] Colorant 0-1 wt%;

[0074] Alkaline inorganic fillers, 0–10 wt%;

[0075] The weight percentage of the colorant and alkaline inorganic filler is not 0;

[0076] The remaining material is polylactic acid, and the total weight percentage of all components is 100 wt%.

[0077] In another specific embodiment, the present invention provides a biodegradable tracer punctum plug, which comprises the following components by weight percentage:

[0078] Colorant 0.01–0.05 wt%;

[0079] Alkaline inorganic filler 0.5–5 wt%;

[0080] The remaining material is polylactic acid, and the total weight percentage of all components is 100 wt%.

[0081] In this embodiment, as an example, the weight percentage of the colorant can be 0.01wt%, 0.02wt%, 0.03wt%, 0.04wt%, or 0.05wt%, as long as the weight percentage of the colorant is within the range of 0.01 to 0.05wt%.

[0082] In some specific embodiments, as an example, the weight percentage of alkaline inorganic filler can be 0.5wt%, 1wt%, 1.5wt%, 2wt%, 2.5wt%, 3wt%, 3.5wt%, 4wt%, 4.5wt%, or 5wt%, as long as the weight percentage of alkaline inorganic filler is within the range of 0.5 to 5wt%.

[0083] In one specific embodiment, the alkaline inorganic filler has a weight percentage of 1 to 2 wt%. Alkaline inorganic fillers within this weight percentage range, when combined with polylactic acid, can achieve better degradation regulation during the use of tear spot plugs.

[0084] In some specific embodiments, the colorant is at least one of D&C Violet 2, D&C Green 6, and [phthalocyanine (2-)]copper. The trade names of the colorants used in this embodiment are as follows:

[0085] D&C Violet No. 2

[0086] D&C Green No. 6

[0087] [Phthalocyaninato(2-)]copper: [Phthalocyaninato(2-)]copper.

[0088] In some specific embodiments, the alkaline inorganic filler is at least one of hydroxyapatite and β-tricalcium phosphate.

[0089] In one specific embodiment, the alkaline inorganic filler is hydroxyapatite.

[0090] In some specific embodiments, the biodegradable tracer tear punctum plug has a diameter of 0.1–1 mm, a length of 0.5–5 mm, and a cylindrical structure.

[0091] In another embodiment, the present invention provides a medical device for treating dry eye syndrome, the medical device comprising a biodegradable tracer punctum plug.

[0092] The present invention will be further illustrated below through specific embodiments:

[0093] Example 1

[0094] (1) Place polylactic acid granules and D&C Violet NO.2 colorant in a sealed bag and shake until uniformly dyed. Dry the polylactic acid at 60°C for 2 hours. The content of the colorant is 0.03wt%.

[0095] (2) The polylactic acid granules processed in step (1) are injected into the micro injection molding machine with temperature control. The hopper preheating temperature is 170°C, the heating end temperature is 180°C, and the injection end temperature is 170°C. The granules are then placed in the mold and kept at 30°C for 10 seconds under 30 MPa pressure.

[0096] (3) Place the sample prepared in step (2) in an oven at 60°C for 1 hour to obtain a biodegradable tracer tear spot plug.

[0097] Example 2

[0098] (1) Place polylactic acid granules and D&C Violet NO.2 colorant in a sealed bag and shake until uniformly dyed. Dry the polylactic acid at 60°C for 2 hours. The content of the colorant is 0.03wt%.

[0099] (2) Place hydroxyapatite (HA) into the mixed particles prepared under the conditions of (1) and continue to shake until uniformly adhered. The HA content is 1 wt%.

[0100] (3) Place the new granules obtained in step (2) into a micro injection molding machine and perform temperature-controlled injection molding. The hopper preheating temperature is 170°C, the heating end temperature is 180°C, the injection end temperature is 170°C, and the granules are placed in the mold at 30°C for 30 MPa for 10 seconds.

[0101] (4) Place the sample prepared in step (3) in an oven at 60°C for 1 hour to obtain a biodegradable tracer tear spot plug.

[0102] Example 3

[0103] (1) Place polylactic acid granules and D&C Violet NO.2 colorant in a sealed bag and shake until uniformly dyed. Dry the polylactic acid at 60°C for 2 hours. The content of the colorant is 0.03wt%.

[0104] (2) Place hydroxyapatite (HA) into the mixed particles prepared under the conditions of (1) and continue to shake until uniformly adhered. The HA content is 2wt%.

[0105] (3) Place the new granules obtained in step (2) into a micro injection molding machine and perform temperature-controlled injection molding. The hopper preheating temperature is 170°C, the heating end temperature is 180°C, the injection end temperature is 170°C, and the granules are placed in the mold at 30°C for 30 MPa for 10 seconds.

[0106] (4) Place the sample prepared in step (3) in an oven at 60°C for 1 hour to obtain a biodegradable tracer tear spot plug.

[0107] Example 4

[0108] (1) Place polylactic acid granules and D&C Violet NO.2 colorant in a sealed bag and shake until uniformly dyed. Dry the polylactic acid at 60°C for 2 hours. The content of the colorant is 0.03wt%.

[0109] (2) Place β-tricalcium phosphate (β-TCP) into the mixed particles prepared under the conditions of (1) and continue to shake until uniformly adhered. The β-TCP content is 1 wt%.

[0110] (3) Place the new granules obtained in step (2) into a micro injection molding machine and perform temperature-controlled injection molding. The hopper preheating temperature is 170°C, the heating end temperature is 180°C, the injection end temperature is 170°C, and the granules are placed in the mold at 30°C for 30 MPa for 10 seconds.

[0111] (4) Place the sample prepared in step (3) in an oven at 60°C for 1 hour to obtain a biodegradable tracer tear spot plug.

[0112] Figure 3 To compare the degradation curves of the punctal plugs in Examples 1-4, the following methods were used. Figure 3 It can be seen that the degradation rate of the biodegradable tracer tear punctum plug obtained in Example 3 was the slowest, followed by Examples 2, 4, and 1. The difference between Examples 1 to 3 lies in the different contents of hydroxyapatite; that is, as the content of hydroxyapatite increases, the anti-degradation performance of the tear punctum plug is better. This means that the present invention can control the degradation time of the tear punctum plug by adjusting the amount of hydroxyapatite used. Simultaneously, a comparison was made... Figure 3As can be seen from the curves of Examples 2 and 4, the degradation performance test results of the two are not significantly different. The only difference between Examples 2 and 4 is that Example 4 uses the same amount of β-tricalcium phosphate to replace the hydroxyapatite in Example 2. It can be seen that both β-tricalcium phosphate and hydroxyapatite can play a good role in regulating degradation performance as alkaline inorganic fillers. That is, the present invention can adjust the service life of tear spot plugs by adjusting the type and amount of alkaline inorganic fillers.

[0113] To further demonstrate the relevant performance of the biodegradable tracer tear punctum plug provided by this invention, several comparative examples are listed below:

[0114] Comparative Example 1

[0115] (1) Dry the polylactic acid granules at 60°C for 2 hours;

[0116] (2) The polylactic acid granules processed in step (1) are injected into the micro injection molding machine with temperature control. The hopper preheating temperature is 170°C, the heating end temperature is 180°C, and the injection end temperature is 170°C. The granules are then placed in the mold and kept at 30°C for 10 seconds under 30 MPa pressure.

[0117] (3) Place the sample prepared in step (2) in an oven at 60°C for 1 hour to obtain biodegradable tear spot plugs.

[0118] The structural morphology of the punctal plugs obtained in Examples 1-2 and Comparative Example 1 under a 10x magnifying glass is as follows: Figure 1 As shown, from left to right are Comparative Example 1 and Examples 1 and 2. (The text repeats itself here.) Figure 1 It is known that polylactic acid is transparent and not easy to observe. However, the addition of D&C Violet NO.2 colorant can significantly improve the observation performance. In clinical use, it can significantly improve the observation ability, prevent loss, and assist doctors in observing the implantation site, thus improving the convenience of the operation.

[0119] Figure 4 The pH curves for the degradation of tear punctum plugs prepared in Comparative Example 1 and Examples 1-4 of this invention are shown. Figure 4 As shown, comparing the pH curves of the tear punctum plug degradation in Example 2 and Example 3, it can be seen that the pH decrease rate in Example 3 is much smaller than that in Example 2. The only difference between Example 3 and Example 2 is that the amount of hydroxyapatite is doubled. Hydroxyapatite is alkaline and can neutralize the acidic environment generated by the degradation of polylactic acid, maintaining the pH balance of the tear punctum plug. That is, the addition of hydroxyapatite can reduce the irritation to the tear punctum, thereby effectively improving the occurrence of inflammation.

[0120] Comparative Example 2

[0121] (1) Dry the polylactic acid granules at 60°C for 2 hours;

[0122] (2) The polylactic acid granules processed in step (1) are injected into the micro injection molding machine with temperature control. The hopper preheating temperature is 170°C, the heating end temperature is 180°C, the injection end temperature is 170°C, and the granules are placed in the mold at 60°C for 10 seconds.

[0123] (3) Place the sample prepared in step (2) in an oven at 60°C for 1 hour to obtain biodegradable tear spot plugs.

[0124] By comparing the preparation methods of the teardrop plugs in Comparative Example 1 and Comparative Example 2, it can be seen that the only difference between them is that the teardrop plug obtained in Comparative Example 2 did not undergo a low-temperature pressure holding treatment. Thermogravimetric experiments were conducted on the teardrop plugs obtained in Comparative Example 1 and Comparative Example 2, and the results are shown in Table 1 and... Figure 2 As shown.

[0125] Table 1. Results of comparative punctal plugging thermogravimetric experiments

[0126]

[0127] pass Figure 2 As shown in Table 1, the low-temperature pressure holding process increased the glass transition temperature (Tg) of the material in Comparative Example 1, thus improving the thermal stability of the material system. Figure 2 The crystallinity of the materials under different processes was calculated using the enthalpy (ΔH) in Table 1. It was further found that the crystallinity of the material in Comparative Example 1, which underwent a low-temperature pressure holding process, was significantly increased. This shows that the present invention can improve the crystallinity of the teardrop plug precursor by performing a low-temperature pressure holding process, thereby avoiding brittle fracture of the biodegradable teardrop plug and exhibiting good stability.

[0128] The extracts of the tear punctum plugs obtained in Examples 1-4 and Comparative Example 1 were analyzed using the CCK-8 assay, and the results are as follows: Figure 5 As shown. (Through) Figure 5 It is known that the addition of colorant does not affect the biocompatibility of the tear punctum plug. That is, the biodegradable tracer tear punctum plug provided by the present invention has good tracer performance, degradation time adjustment performance and stability performance, and has good application prospects.

[0129] It should be understood that the application of the present invention is not limited to the examples above. Those skilled in the art can make improvements or modifications based on the above description, and all such improvements and modifications should fall within the protection scope of the appended claims.

Claims

1. A biodegradable tracer tear punctum plug, characterized in that, It includes the following components, expressed as a percentage by weight: Colorant 0-1 wt%; Alkaline inorganic fillers, 0–10 wt%; The weight percentage of the colorant and alkaline inorganic filler is not 0; The remaining material is polylactic acid, and the total weight percentage of all components is 100 wt%.

2. The biodegradable tracer tear punctum plug according to claim 1, characterized in that, It includes the following components, expressed as a percentage by weight: Colorant 0.01–0.05 wt%; Alkaline inorganic filler 0.5–5 wt%; The remaining material is polylactic acid, and the total weight percentage of all components is 100 wt%.

3. The biodegradable tracer tear punctum plug according to any one of claims 1-2, characterized in that, The alkaline inorganic filler has a weight percentage of 1-2 wt%. The alkaline inorganic filler includes at least one of hydroxyapatite and β-tricalcium phosphate.

4. The biodegradable tracer tear punctum plug according to claim 3, characterized in that, The colorant includes at least one of D&C Violet 2, D&C Green 6, and [phthalocyanine (2-)]copper.

5. The method for preparing the biodegradable tracer tear punctum plug according to any one of claims 1-4, characterized in that, Includes the following steps: Colored polylactic acid is obtained by mixing polylactic acid with a coloring agent; The colored polylactic acid is mixed with an alkaline inorganic filler to obtain a mixture; The mixture is subjected to injection molding to obtain an injection molded product; The injection-molded product was treated at 25–40°C and 20–50 MPa for 5–120 s to obtain a tear spot plug precursor. The teardrop plug precursor was heat-insulated to obtain a biodegradable tracer teardrop plug.

6. The method for preparing the biodegradable tracer tear punctum plug according to claim 5, characterized in that, The polylactic acid needs to be dried at a temperature of 50–70°C for 1–3 hours.

7. The method for preparing the biodegradable tracer tear punctum plug according to claim 5, characterized in that, The injection molding includes segmented temperature-controlled injection molding, and the conditions for segmented temperature-controlled injection molding include: The hopper preheating temperature is 160-180℃; The heating end temperature is 170–200℃; The injection end temperature is 160-180℃.

8. The method for preparing the biodegradable tracer tear punctum plug according to claim 5, characterized in that, The temperature for heat preservation of the tear spot plug precursor is 40-80℃, and the time is 0.5-1.5h.

9. The use of the biodegradable tracer punctal plug according to any one of claims 1 to 4 or the preparation method according to any one of claims 5 to 8 in the preparation of a medical device for treating dry eye syndrome.

10. A medical device for treating dry eye syndrome, characterized in that, The medical device includes the biodegradable tracer punctal plug as described in any one of claims 1 to 4.

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