Metalloflavin nanomaterial and trans-epithelial corneal cross-linking formulation
Metallic riboflavin nanomaterials were prepared by coordinating and modifying metal ions on the -HPO4- group of sodium riboflavin phosphate, which solved the problem of insufficient efficacy of transepithelial corneal cross-linking and achieved efficient corneal cross-linking effect and wide applicability.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- EYE & ENT HOSPITAL SHANGHAI MEDICAL SCHOOL FUDAN UNIV
- Filing Date
- 2023-08-17
- Publication Date
- 2026-06-02
AI Technical Summary
The efficacy of current transepithelial corneal crosslinking is controversial. Postoperatively, 30-50% of patients experience disease progression, mainly due to insufficient riboflavin content in the stromal layer. This makes it impossible to achieve crosslinking effects comparable to classic methods while preserving the corneal epithelium.
Metallic riboflavin nanomaterials were prepared by coordinating and modifying metal ions on the -HPO4- group of sodium riboflavin phosphate, thereby improving their hydrophilicity and transepithelial delivery ability and forming a transepithelial corneal cross-linking formulation.
It significantly increases the content of riboflavin in the stromal layer, achieving results comparable to epithelial corneal cross-linking, reducing postoperative complications, expanding the scope of surgical applications, and improving patient comfort.
Smart Images
Figure CN117257833B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of ophthalmic medication technology, specifically relating to a metalloriboflavin nanomaterial and a transepithelial corneal cross-linking preparation. Background Technology
[0002] Blinding keratoconus is a common degenerative non-inflammatory corneal disease characterized by progressive thinning of the corneal stroma, resulting in a conical protrusion. It manifests as myopia, irregular astigmatism, scarring, nodules, and axial curvature abnormalities, leading to blurred vision, double vision, glare, and other visual problems. It is characterized by continuous deterioration and irreversibility.
[0003] Riboflavin (Rf) combined with ultraviolet A (UVA) corneal cross-linking (CXL) is currently the internationally recognized primary treatment for pathologically halting and delaying the progression of keratoconus, improving the biomechanics and stromal instability of keratoconus. To date, CXL has been applied to the treatment of various corneal diseases, such as keratoconus, infectious keratitis, corneal ulcers, and bullous keratopathy, delaying or even halting the progression of keratoconus to avoid the need for corneal transplantation and alleviate the clinical shortage of corneal donors.
[0004] To date, the primary treatment for keratoconus has been the classic corneal cross-linking (SCXL) protocol, also known as the Dresden protocol. This requires the mechanical removal of the lipophilic corneal epithelium to allow for effective penetration of hydrophilic riboflavin into the hydrophilic stroma. While the treatment outcome is relatively stable, the removal of the corneal epithelium can lead to common problems such as long-term postoperative pain and slow visual recovery, as well as serious complications including corneal infection, edema, scarring, corneal perforation, and even blindness. Furthermore, the classic protocol is not suitable for patients with corneal thickness below 400 μm, meaning that most patients in the middle to late stages often fail to meet the surgical inclusion criteria due to excessively thin corneas. Therefore, epithelial-preserving corneal cross-linking (T-CXL) has emerged. It avoids many of the problems associated with epithelial-removing cross-linking protocols, offering advantages such as lower postoperative infection risk, fewer complications, broader inclusion criteria, and higher patient comfort, making it a current research hotspot. However, the efficacy of transepithelial corneal cross-linking in clinical practice remains controversial. Postoperatively, 30-50% of patients experience disease progression, primarily due to insufficient riboflavin content in the stroma during the cross-linking process. Therefore, how to increase the riboflavin content in the stroma while preserving the integrity of the corneal epithelium, ensuring sufficient riboflavin enters the stroma to achieve corneal cross-linking effects comparable to classic methods, is an international research hotspot and a crucial problem urgently needing to be solved. Summary of the Invention
[0005] The purpose of this invention is to overcome the shortcomings and deficiencies of the existing technology and to provide a metalloriboflavin nanomaterial and a transepithelial corneal cross-linking preparation.
[0006] The technical solution adopted in this invention is as follows: a metal riboflavin nanomaterial, which is obtained by coordinating and modifying metal ions on the -HPO4- group of sodium riboflavin phosphate.
[0007] As a further preferred method, the preparation method includes the following steps: adding metal ions to a riboflavin sodium phosphate solution and reacting to obtain metalloriboflavin nanomaterials.
[0008] As a further preferred option, the solvent for the riboflavin sodium phosphate solution is methanol and / or ethanol. After the reaction, a precipitate is formed. The precipitate is then washed to obtain the metalloriboflavin nanomaterial.
[0009] As a further preferred option, the reaction time is 4-24 h.
[0010] A transepithelial corneal crosslinking formulation comprising the metalloriboflavin nanomaterials described above.
[0011] As a further preferred option, the concentration of riboflavin phosphate in the formulation is 2-6 mg / ml.
[0012] The beneficial effects of this invention are as follows: This invention targets the hydrophilic and negatively charged properties of riboflavin phosphate (Rfp) molecules, combining the structural characteristics of corneal epithelium's lipophilicity and the stroma's hydrophilicity. It innovatively designs and constructs metalloriboflavin (nRfpM) nanomaterials by coordinating and modifying the -HPO4- groups that enhance the hydrophilicity of Rfp molecules with metal ions (Mn+). The lipophilicity of this nRfpM nanomaterial is greatly enhanced due to the coordination of Mn+ with the -HPO4- groups that improve the hydrophilicity of Rfp molecules, thereby improving the transepithelial delivery capability of the nRfpM nanomaterial. This significantly improves the transepithelial corneal cross-linking effect of the obtained product, achieving results comparable to clinical deepithelial corneal cross-linking. This provides a new type of reagent for transepithelial corneal cross-linking and has significant clinical application prospects. Attached Figure Description
[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, obtaining other drawings based on these drawings without creative effort still falls within the scope of the present invention.
[0014] Figure 1 The images show XRD patterns of the nRfpZn, nRfpBi, and nRfpZr nanomaterials prepared according to this invention.
[0015] Figure 2 SEM images of the nRfpZn, nRfpBi, and nRfpZr nanomaterials prepared in this invention.
[0016] Figure 3 The contact angle of the nRfpZn, nRfpBi, and nRfpZr nanomaterials prepared in this invention is shown.
[0017] Figure 4 Slit-lamp photographs of the nRfpZn, nRfpBi, and nRfpZr nanomaterials prepared in this invention after infiltration into the living cornea.
[0018] Figure 5 This study presents an experiment on the anti-enzyme dissolution of the nRfpZn, nRfpBi, and nRfpZr nanomaterials prepared in this invention through cross-linking across the epithelial cornea.
[0019] Figure 6 Corneal enzyme resistance experiments were conducted on the cross-linking of nRfpZn, nRfpBi, and nRfpZr nanomaterials across the cornea. Detailed Implementation
[0020] This invention provides a metal riboflavin nanomaterial, which is obtained by coordinating and modifying metal ions on the -HPO4- group of sodium riboflavin phosphate.
[0021] The chemical formula of riboflavin sodium phosphate is as follows:
[0022] ,
[0023] The -HPO4- group, possessing hydrophilic and negatively charged properties, can act as a ligand to complex with metal ions to form complexes. In this invention, the metal ion (Mn+) does not refer to all metal ions, but rather to all metal ions in the periodic table that can coordinate with Rfp molecules. Those skilled in the art can select suitable metal ions based on relevant well-known theories of coordination chemistry or through a limited number of experiments. In some embodiments of this invention, the metal ions (Mn+) that can coordinate with Rfp molecules include at least Bi3+, Zn2+, Zr4+, Fe3+, Fe2+, Mn2+, Ce3+ (other rare earth ions Ln3+), Ca2+, Mg2+, Cu2+, Al3+, and Mo5+, and the metalloriboflavin composite nanomaterials prepared using the above-mentioned metal ions all achieve excellent transepithelial riboflavin delivery capabilities.
[0024] In some embodiments of the present invention, the preparation method includes the following steps: adding metal ions to a riboflavin sodium phosphate solution and reacting to obtain metalloriboflavin nanomaterials. Specifically, the solvent of the riboflavin sodium phosphate solution is methanol and / or ethanol. Rfp molecules are soluble in methanol and ethanol. The reaction product nRfpM obtained by modifying the -HPO4- group with metal ions (Mn+) will precipitate out. The lipophilicity of this precipitate is greatly improved due to the coordination of Mn+ with the -HPO4- group that enhances the hydrophilicity of Rfp molecules, thereby improving the transepithelial delivery capability of the product nRfpM nanomaterials and greatly improving the transepithelial corneal cross-linking effect of the obtained product.
[0025] Some embodiments of the present invention will be described below.
[0026] Example 1:
[0027] A methanol solution of BiCl3 / Bi(NO3)3 and Rfp was rapidly added together and stirred thoroughly at room temperature for 2–8 h, then allowed to stand overnight. The mixture was then centrifuged, washed, and sieved to obtain nRfpBi nanomaterials.
[0028] The resulting aqueous solutions of different components were then dropped onto the ocular surface of rabbits, with the immersion time controlled at 30 min. Subsequently, the central 8.0 mm cornea was irradiated with a 365 nm UVA crosslinker at 0.3 W / cm² for 30 min. The corresponding nRfpBi nanomaterial solution was added again at 3.3 min and 6.7 min of irradiation. After irradiation, the cornea was immediately rinsed with PBS solution, and corneal immersion laboratory and corneal anti-enzyme dissolution experiments were performed.
[0029] Example 2:
[0030] By replacing the zinc salt (ZnCl2) with the raw material BiCl3 / Bi(NO3)3, nRfpZn nanomaterials were prepared using the same method.
[0031] Example 3:
[0032] By replacing the raw material BiCl3 / Bi(NO3)3 with zirconium salt (ZrCl4), nRfpZr nanomaterials were prepared using the same method.
[0033] Depend on Figure 1 The XRD patterns of nRfpZn, nRfpBi, and nRfpZr nanomaterials are shown. It can be seen from the figure that the phase structure of the obtained product is different from both Rfp and riboflavin, indicating that a new substance is formed. Moreover, the phase structure of the product is different depending on the metal ion.
[0034] Depend on Figure 2 SEM images of nRfpZn, nRfpBi, and nRfpZr nanomaterials show that the morphology of the obtained products varies depending on the metal ions.
[0035] Figure 3 The figure shows the contact angle results of the nRfpZn, nRfpBi, and nRfpZr nanomaterials prepared in this invention. As can be seen from the figure, compared with hydrophobic riboflavin and hydrophilic Rfp, the coordination of the three ions Zn2+, Bi3+, and Zr4+ with the -HPO4- group in the Rfp molecule greatly improves the lipophilicity of the nRfpBi nanomaterial, from the initial 18.98° to more than 100° of the final product, transforming it from a hydrophilic material to a lipophilic material.
[0036] Figure 4 Slit-lamp images of the cornea after immersion in living corneas with nRfpZn, nRfpBi, and nRfpZr nanomaterials for 30 minutes. For the same immersion time, the cornea of the nRfpM nanomaterial group was more yellow than that of the positive experimental group, indicating a higher riboflavin content.
[0037] Figure 5The study investigated the anti-enzymatic dissolution of cornea after cross-linking of nRfpZn, nRfpBi, and nRfpZr nanomaterials across the epithelial cornea. Compared with the negative and positive control groups, after 48 hours, the remaining corneal area and dry weight in the nRfpM nanomaterial group were higher than those in the positive group, while the negative group completely dissolved after 8 hours. This indicates that the nRfpM nanomaterial group has a corneal cross-linking effect comparable to that of the positive experimental group under the premise of cross-epithelial drug delivery.
[0038] Figure 6 The study investigated the anti-enzymatic dissolution of cornea after cross-linking of nRfpZn, nRfpBi, and nRfpZr nanomaterials across the epithelial cornea. Compared with the negative and positive control groups, after 48 hours, the remaining corneal area and dry weight in the nRfpM nanomaterial group were higher than those in the positive group, while the negative group completely dissolved after 8 hours. This indicates that the nRfpM nanomaterial group has a corneal cross-linking effect comparable to that of the positive experimental group under the premise of cross-epithelial drug delivery.
[0039] The above description discloses only preferred embodiments of the present invention and should not be construed as limiting the scope of the present invention. Therefore, equivalent variations made in accordance with the claims of the present invention are still within the scope of the present invention.
Claims
1. The application of metalloriboflavin nanomaterials in the preparation of formulations that promote the cross-linking effect of riboflavin across the epithelial cornea, characterized in that: which is a coordination modification of a metal ion on a -HPO4 - group on riboflavin sodium phosphate The metal ion is Bi. 3+ Zn 2+ Zr 4+ Fe 3+ Fe 2+ Mn 2+ Ce 3+ Ca 2+ Mg 2+ Cu 2+ Al 3+ Mo 5+ One of them.
2. The application according to claim 1, characterized in that: The preparation method of the metal riboflavin nanomaterial includes the following steps: adding metal ions to a riboflavin sodium phosphate solution and reacting to obtain the metal riboflavin nanomaterial.
3. The application according to claim 2, characterized in that: The solvent for the riboflavin sodium phosphate solution is methanol and / or ethanol. After the reaction, a precipitate is formed. The precipitate is then washed to obtain the metalloriboflavin nanomaterial.
4. The application according to claim 2, characterized in that: The reaction time is 4-24 h.