Soluble microneedle patch for ultraviolet sclera crosslinking and preparation method thereof

Abstract

The invention provides a soluble microneedle patch for ultraviolet sclera crosslinking and a preparation method of the soluble microneedle patch, and relates to the field of biomedical materials. The soluble microneedle patch for ultraviolet sclera crosslinking comprises a microneedle body and a substrate layer, wherein the microneedle body and the substrate layer comprise polyvinyl alcohol and oxygen-carrying riboflavin lipidosome. After the soluble microneedle patch is applied, the bulbar conjunctiva does not need to be cut off in a large area, so that the operation time is shortened, the operation injury is reduced, the discomfort of a patient is relieved, and the operation safety is improved. Secondly, the height of the microneedle is individually designed according to different thicknesses of the sclera of the eyeball, so that the sclera is punctured in a safe and minimally invasive manner, and the operation safety is improved. And finally, after the soluble microneedle patch is applied, the automation of riboflavin perfusion is realized, the riboflavin solution does not need to be manually and frequently dropwise added, the surgical operation is simplified, and the surgical efficiency is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of biomedical materials, in particular to a soluble microneedle patch for ultraviolet sclera cross-linking and a preparation method thereof. BACKGROUND

[0002] At present, the number of myopia population in the world is growing, and the rapid growth of myopia incidence has attracted social attention. Research predicts that there will be nearly 1 billion high myopia population in the world by 2050. 61.7% of high myopia population will develop serious complications, such as posterior scleral staphyloma, myopic maculopathy and high myopic optic neuropathy, and other posterior segment structural changes, which may lead to loss of best corrected visual acuity, and seriously reduce the quality of life of patients.

[0003] For those who have a high risk of developing high myopia or are not sensitive to conventional conservative methods for controlling axial growth, surgical methods such as posterior sclera reinforcement and sclera collagen cross-linking can be used to delay the development from high myopia to pathological myopia.

[0004] Ultraviolet-riboflavin sclera collagen cross-linking is a method that effectively improves the biomechanical properties of the sclera by increasing the covalent bond between or within the scleral collagen fibers. Animal studies have confirmed the effectiveness of this method in slowing down the growth of the eye axis and delaying the progression of myopia. In the prior art, the surgeon infiltrates the sclera by manually adding riboflavin, and then uses a separate ultraviolet light irradiation device to irradiate for 30 minutes to complete the cross-linking operation.

[0005] However, the above method requires a large area of separated bulbar conjunctiva and pulling of the eyeball to expose the target sclera to achieve effective cross-linking range. However, this method is complex to operate, has a large surgical wound, takes a long time, increases the risk of infection and discomfort of the patient. In order to achieve an effective riboflavin concentration in the sclera, the surgeon needs to manually add riboflavin solution frequently, which wastes manpower, may cause operational errors, and the cross-linking process consumes a large amount of oxygen, while the oxygen content in the deep sclera tissue is low, making it difficult to achieve good cross-linking effect. SUMMARY

[0006] Therefore, in order to solve these problems, the present inventors designed and prepared an oxygen-carrying soluble riboflavin microneedle patch, which is designed with individualized microneedle height according to the scleral thickness of different myopia patients, aiming to penetrate the sclera in a safe and minimally invasive manner to improve the penetration of riboflavin, increase the oxygen content of the sclera tissue, and further improve the effectiveness and safety of ultraviolet-riboflavin sclera cross-linking, providing a new idea for delaying the progression of myopia.

[0007] The technical problem to be solved by the present application (invention purpose) is:

[0008] 1. Reduce surgical wound, shorten operation time, reduce surgical damage, reduce patient discomfort, increase surgical safety.

[0009] 2. Realize the automation of riboflavin perfusion, without manual frequent drop of riboflavin solution, simplify the operation, improve the operation efficiency.

[0010] 3. Micro-needle puncture sclera increases riboflavin sclera penetration, and oxygen-carrying soluble particles increase the oxygen concentration of sclera tissue, thereby improving the effect and accuracy of sclera cross-linking.

[0011] Specifically, the present application provides:

[0012] A soluble microneedle patch for ultraviolet light sclera cross-linking, the soluble microneedle patch comprising a microneedle body and a substrate layer, the microneedle body and the substrate layer comprising polyvinyl alcohol and oxygen-carrying riboflavin liposomes.

[0013] Optionally, the oxygen-carrying riboflavin liposomes comprise riboflavin, oxygen, lecithin and a sterol.

[0014] Optionally, the molecular weight of the polyvinyl alcohol is 200,000 Daltons.

[0015] Optionally, the height of the microneedle body is 487±12μm, the width of the substrate layer is 306±10μm, and the thickness of the substrate layer is 51±8μm.

[0016] Optionally, the microneedle patch is circular with a diameter of 6-10mm, preferably 7mm.

[0017] The preparation method of the soluble microneedle patch comprises:

[0018] (1) Preparation of oxygen-carrying riboflavin liposome particles: lecithin and sterol are prepared into liposomes, the liposomes are configured into a suspension with 1% perfluorooctane solution, riboflavin is added and the riboflavin concentration is adjusted to 0.05%-0.2%, preferably 0.1%, and oxygen is introduced;

[0019] (2) Preparation of soluble microneedle patch: the oxygen-carrying riboflavin liposome particles prepared in step (1) are dissolved in a polyvinyl alcohol solution with a mass ratio of 5%-10%, preferably 10%, the obtained polyvinyl alcohol solution containing oxygen-carrying riboflavin liposome particles is added to a microneedle mold, dried, and demolded to obtain the soluble microneedle patch.

[0020] Optionally, in step (1), the mass ratio of lecithin to sterol is 5:1;

[0021] And / or, in step (1), the weight ratio of 1% perfluorooctane to liposomes is 30%-80%, preferably 40%-70%, more preferably 70%.

[0022] Optionally, in step (2), the content of the liposome particles containing oxyphoric riboflavin in the polyvinyl alcohol solution is 0.08%-1.4% by weight, preferably 0.6%-0.8% by weight.

[0023] And / or, the molecular weight of the polyvinyl alcohol is 200,000 Dalton.

[0024] The application of the soluble microneedle patch in the preparation of a kit for treating myopia.

[0025] A kit for treating myopia, the kit comprising: the soluble microneedle patch.

[0026] The present application can achieve the following beneficial technical effects:

[0027] 1. After applying the oxyphoric soluble riboflavin microneedle patch, a 8mmx10mm conjunctival sac minimally invasive incision is made in the ultraviolet light-riboflavin scleral collagen crosslinking procedure to insert the riboflavin microneedle patch into the sclera of the treatment area, without the need to cut open the bulbar conjunctiva in a large area, thereby shortening the operation time, reducing surgical damage, reducing patient discomfort, and increasing surgical safety.

[0028] 2. The sclera of patients with high myopia is significantly thinned, and the sclera thinning area varies among different patients. Therefore, the present application designs the microneedle height and size according to the sclera thinning thickness and area of different eyeballs, thereby ensuring the positioning of the sclera in a safe and minimally invasive manner, increasing the safety of the operation, and realizing personalized surgical design.

[0029] 3. After applying the oxyphoric soluble riboflavin microneedle patch, the microneedle pierces the sclera to form a micropore, the microneedle base layer continuously dissolves and releases riboflavin liposomes, and the riboflavin liposomes enter the scleral tissue through the micropore, achieving automatic riboflavin perfusion without manual frequent addition of riboflavin solution, simplifying the operation, improving the operation efficiency, and increasing the scleral penetration of riboflavin by piercing the sclera with microneedles, and increasing the oxygen concentration of the scleral tissue by the oxyphoric soluble particles, thereby improving the effect and precision of scleral crosslinking. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0031] Figure 1 The microneedle patch topography provided for Embodiment 1 of the present application;

[0032] Figure 2 The diagram shows the mechanical properties of the microneedles provided in Embodiment 1 of the present invention;

[0033] Figure 3 The image shows the effect of microneedle puncture of the sclera of a pig eye (×400) provided in Embodiment 1 of the present invention;

[0034] Figure 4 This is a scanning electron microscope image of a microneedle provided in Embodiment 2 of the present invention;

[0035] Figure 5 This is a diagram of the microneedle dissolution performance provided in Example 2 of the present invention (scale bar = 500 μm).

[0036] Figure 6 The image shows the riboflavin fluorescence analysis of porcine sclera tissue after drug administration using microneedle patches with different drug loading amounts provided in Example 2 of this invention (compared with the control group, ns = P>0.05). <0.05, <0.001, <0.0001);

[0037] Figure 7 The graph shows the tissue riboflavin concentration after administration of microneedle patches with different drug loadings to the sclera of pigs provided in Example 2 of this invention (compared with the control group, ns = P>0.05). <0.01, <0.0001);

[0038] Figure 8 This diagram illustrates the preparation and use process of the microneedle patch of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings. The following embodiments are for illustrative purposes only and should not be considered as limiting the scope of the invention.

[0040] Current scleral cross-linking methods require large-area separation of the bulbar conjunctiva and traction of the eyeball to expose the target sclera. This method is complex, involves large surgical wounds, is time-consuming, and significantly increases the risk of infection and patient discomfort. In contrast, when using the soluble microneedle patch of this invention for riboflavin delivery, only a small incision of about 8mm is required, reducing the surgical wound and exposure.

[0041] The current administration of riboflavin is through manual frequent drop of riboflavin solution, every 3 minutes of light sensitizer solution containing 0.1% riboflavin is dropped on the exposed sclera to ensure that riboflavin completely penetrates into the sclera stroma, after 20 minutes of riboflavin soaking time, ultraviolet light crosslinking is started. When the riboflavin is delivered by the soluble microneedle patch of the application, the microneedle patch can dissolve and release riboflavin within 5 minutes and quickly penetrate into the sclera stroma under the action of microneedle puncture, shortening the operation time.

[0042] Example 1

[0043] 1. Preparation of oxygen-carrying riboflavin liposome particles

[0044] Lecithin and sterol are prepared into liposomes (LP) at a mass ratio of 5:1, then 1% perfluorooctane (PFC) and liposomes are prepared into a suspension at 40%, 50%, 60%, and 70%, riboflavin (RF) is added and the concentration of riboflavin is adjusted to 0.1%, and RF-PFC-LP suspension is prepared. Use the oxygen generator to pass 95% oxygen into the RF-PFC-LP suspension at a flow rate of 4L / min for 5 minutes and store at room temperature.

[0045] The concentration of riboflavin in the RF-PFC-LP suspension is detected. The detection method is as follows: the same volume of different concentrations of suspension is taken and placed in a 96-well plate with a prepared riboflavin standard curve solution (highest concentration 2% gradient diluted 8 times), and the absorbance of riboflavin is detected in an enzyme marker. The linear relationship between riboflavin concentration and absorbance is obtained by detecting the riboflavin standard curve solution. The absorbance of the test solution corresponds to the standard curve to calculate the concentration of riboflavin in the suspension.

[0046] The dissolved oxygen concentration of RF-PFC-LP within 5, 10, 15 minutes is detected, so as to screen out liposome particles with the best oxygen-carrying and drug-carrying capacity. The detection method is as follows: use the dissolved oxygen detector to detect the liposome suspension after standing at room temperature for a period of time, confirm the stable degree, pass 95% oxygen at a flow rate of 4L / min for 10 minutes, and use the dissolved oxygen detector to confirm that the oxygen concentration in the suspension is stable and no longer increases. Then use the dissolved oxygen detector to detect the oxygen concentration in the suspension after 5, 10, 15 minutes.

[0047] 2. Screening of riboflavin soluble microneedle patch with the best physicochemical properties

[0048] Different molecular weight of polyvinyl alcohol (PVA) (~10w, ~20w molecular weight) was dissolved in pure water at different concentrations of 5%, 10%, 15%, 20mg of oxygen-carrying liposome particles were dissolved in 10mL PVA solution, 0.5mL PVA solution was added to the polydimethylsiloxane (PDMS) mold, dried in a 37℃ oven overnight, and the microneedle patch was obtained after demolding. The microneedle morphology was evaluated by microscope.

[0049] 3. Mechanical property evaluation of different PVA content soluble microneedle patches

[0050] The obtained soluble microneedle patches with different PVA content were placed in a universal testing machine, and the force-displacement curve was drawn to evaluate the mechanical properties of the microneedles.

[0051] 4. Sclera penetration ability of soluble microneedle patches with different PVA content

[0052] The obtained soluble microneedle patches with different PVA content were placed on the isolated porcine sclera, and the microneedle patch was removed after pressing for 5s. The tissue at the pressing site was fixed, embedded, sectioned and H&E stained, and the sclera penetration was observed under a microscope.

[0053] Experimental results:

[0054] 1. Characterization of oxygen-carrying liposome particles:

[0055] The concentration of riboflavin in the suspension prepared by mixing 1% PFC with liposomes at a ratio of 40%~70% was 0.149mg / mL to 0.155mg / mL, and the suspension prepared by mixing 1% PFC with liposomes at a ratio of 70% (containing riboflavin 0.154±0.006mg / mL) was preferred.

[0056] The suspension prepared by mixing 1% PFC with liposomes at a ratio of 40%~70% released oxygen 21mg / mL to 33mg / mL within 15 minutes, and the suspension prepared by mixing 1% PFC with liposomes at a ratio of 70% (releasing oxygen 33±1mg / mL within 15 minutes) was preferred.

[0057] The results are shown in Tables 1 and 2 as follows:

[0058] Table 1: Concentration of riboflavin in RF-PFC-LP

[0059]

[0060] Table 2: Dissolved oxygen concentration (mg / mL) of RF-PFC-LP within 15 minutes

[0061]

[0062] 2. Riboflavin-containing soluble microneedle patch screening:

[0063] The experimental results are shown in Figure 1 From Figure 1 the results, the inventors observed the morphology of the prepared microneedle patch by microscope. The microneedle patch was circular with a diameter of 7 mm, and each microneedle patch contained 101 needles. When the PVA concentration was 5% and 10%, the microneedle patch had good formability, and when the concentration increased to 15%, the microneedle patch was severely shrunk as a whole and did not have good formability.

[0064] 3. Evaluation of the mechanical properties of riboflavin-containing microneedle patches:

[0065] The experimental results are shown in Figure 2 From Figure 2 the results, it can be seen that the compression force of the four groups of different microneedles increased with the increase of the deformation displacement of the microneedle tip. Different molecular weight groups did not show a clear turning point, and presented a relatively continuous deformation. More importantly, the 20w microneedle had stronger mechanical properties than the 10w microneedle, and the microneedle prepared from 10% concentration of 20w PVA had the best mechanical properties.

[0066] 4. Evaluation of the sclera penetration ability of riboflavin microneedle patches:

[0067] The experimental results are shown in Figure 3 From Figure 3 the results, it can be seen that the microneedle patches of the 10w PVA-5%, 10w PVA-10% and 20w PVA-5% groups did not cause the pig eye sclera tissue to be penetrated. The 20w PVA-10% group showed obvious penetration of the pig sclera tissue surface layer, which was consistent with the results of the mechanical properties of the microneedles.

[0068] Example 2

[0069] The following illustrates the preparation method and characterization of the soluble microneedle patch for ultraviolet sclera crosslinking of the present application, but the present application is not limited thereto. The soluble microneedle patches prepared by the method of the present application can all achieve similar effects. Hereinafter, they will not be described one by one.

[0070] 1. Preparation of riboflavin-containing soluble microneedle patch

[0071] (1) Preparation of oxygen-carrying liposomal riboflavin particles: liposomes (LP) were prepared from lecithin and cholesterol at a mass ratio of 5:1, followed by 1% perfluorooctane (PFC) and liposomes at a ratio of 40%-70% to prepare a suspension, and then riboflavin (RF) was added and the riboflavin concentration was adjusted to 0.05%-0.2% to prepare an RF-PFC-LP suspension. An oxygen generator was used to introduce 95% oxygen into the RF-PFC-LP suspension at a flow rate of 4 L / min for 5 minutes, and then stored at room temperature.

[0072] (2) 1 g of PVA (~20 w) was dissolved in 10 mL of pure water, 20 mg of oxygen-carrying liposomal riboflavin particles was dissolved in 10 mL of 10% PVA solution, 0.3 mL of PVA solution containing oxygen-carrying liposomal riboflavin was added to a polydimethylsiloxane (PDMS) mold, and dried in a 37°C oven overnight. After demolding, an oxygen-carrying soluble riboflavin microneedle patch was obtained.

[0073] 2. Characterization of oxygen-carrying soluble riboflavin microneedle patch

[0074] The microneedles were characterized by scanning electron microscopy, including microneedle morphology, height, and base layer width. The microneedle patch was circular with a diameter of 7 mm (personalized design for different patients).

[0075] The microneedle dissolution performance was evaluated using an inverted microscope. The experiment to evaluate the microneedle dissolution performance was to dissolve the microneedles in phosphate buffer and observe the microneedle dissolution at different times (0s, 20s, 30s, 60s, 90s, 120s, 5min) using an inverted microscope.

[0076] 3. Scleral drug distribution of different drug-loaded soluble microneedle patches

[0077] Different drug-loaded (i.e., different riboflavin content) soluble microneedle patches were placed on the isolated porcine sclera, and after 5 minutes, the scleral tissue was taken for drug (i.e., riboflavin) concentration determination. The detection method was as follows: each piece of porcine sclera was weighed, cut, and ground. The tissue homogenate supernatant was extracted and placed in a 96-well plate, and the absorbance was detected in the enzyme marker along with the riboflavin standard curve solution. The riboflavin content in the test tissue was calculated by referring to the riboflavin standard curve. The riboflavin content of each piece of tissue divided by the mass of the scleral tissue was the riboflavin concentration of the tissue.

[0078] Experimental results:

[0079] 1. Characterization of 10% PVA oxygen-carrying riboflavin microneedle patch:

[0080] The experimental results are shown in Figure 4 and Figure 5 . From Figure 4It can be seen that the microneedle body is conical in shape, with a height of 487±12μm, a base width of approximately 306±10μm, and a base thickness of approximately 51±8μm. From Figure 5 It can be seen that as time goes on, the microneedle tip dissolves continuously, and the drug in the tip is released accordingly. At 120 seconds, the drug in the microneedle tip is almost completely released.

[0081] 2. Scleral drug distribution in soluble microneedle patches with different drug loading capacities:

[0082] Experimental results are as follows Figure 6 and Figure 7 As shown. From Figure 6 It can be seen that when the drug loading of microneedles is 0-4mg, the concentration of riboflavin in the sclera increases with the increase of drug loading of microneedles. When the drug loading of microneedles reaches 4mg or more, the concentration of riboflavin in the sclera reaches saturation.

[0083] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A soluble microneedle patch for ultraviolet light scleral crosslinking, the soluble microneedle patch comprising microneedle bodies and a base layer, characterized in that, The microneedle body and base layer comprise polyvinyl alcohol and oxygen-carrying riboflavin liposomes.

2. The soluble microneedle patch according to claim 1, characterized in that, The oxygen-carrying riboflavin liposomes include riboflavin, oxygen, lecithin, and sterols.

3. The soluble microneedle patch according to claim 1 or 2, characterized in that, The molecular weight of the polyvinyl alcohol is 200,000 Daltons.

4. The soluble microneedle patch according to claim 1 or 2, characterized in that, The height of the microneedle body is 487±12μm, the width of the base layer is 306±10μm, and the thickness of the base layer is 51±8μm.

5. The soluble microneedle patch according to claim 1 or 2, characterized in that, The microneedle patch is circular with a diameter of 6-10 mm, preferably 7 mm.

6. The method for preparing the soluble microneedle patch according to any one of claims 1-5, characterized in that, include: (1) Preparation of oxygen-carrying riboflavin liposome particles: lecithin and sterol are used to prepare liposomes, the liposomes are prepared into a suspension with 1% perfluorooctane solution, riboflavin is added and the riboflavin concentration is adjusted to 0.05%-0.2%, preferably 0.1%, and oxygen is introduced; (2) Preparation of soluble microneedle patch: Dissolve the oxygen-carrying riboflavin liposome particles prepared in step (1) in a polyvinyl alcohol solution with a mass ratio of 5%-10%, preferably 10%. Add the resulting polyvinyl alcohol solution containing oxygen-carrying riboflavin liposome particles into a microneedle mold, dry it, and demold to obtain the soluble microneedle patch.

7. The preparation method according to claim 6, characterized in that, In step (1), the mass ratio of lecithin to sterol is 5:1; And / or, in step (1), the weight ratio of the 1% perfluorooctane to the liposomes is 30%-80%, preferably 40%-70%, more preferably 70%.

8. The preparation method according to claim 6 or 7, characterized in that, In step (2), the content of the oxygen-carrying riboflavin liposome particles in the polyvinyl alcohol solution containing the oxygen-carrying riboflavin liposome particles is 0.08%-1.4% by weight, preferably 0.6%-0.8% by weight. And / or, the molecular weight of the polyvinyl alcohol is 200,000 Daltons.

9. The use of the soluble microneedle patch according to any one of claims 1-5 in the preparation of a kit for treating myopia.

10. A reagent kit for treating myopia, characterized in that, The kit comprises: a soluble microneedle patch according to any one of claims 1-5.

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