A multi-layer structure of oral phenylalanine ammonia lyase particles

Abstract

The utility model relates to protein medicine delivery technical field especially, it relates to a kind of multi-layer structure of oral phenylalanine ammonia lyase particle. Including inner core layer, the bionic protective layer that is coated in the outer of the inner core layer, the intelligent response layer with according to PH value shrinkage and expansion function that is coated in the outer of the bionic protective layer, the targeting anchoring layer that is coated in the outer of the intelligent response layer;The inner core layer is the porous structure for wrapping and fixed phenylalanine ammonia lyase.This application is combined design by inner core layer, bionic protective layer, intelligent response layer and targeting anchoring layer, significantly enhance the stability and catalytic efficiency of PAL in gastrointestinal tract, and continuously play a role in intestinal tract by immobilization mode.

Description

Technical Field

[0001] This invention relates to the field of protein drug delivery technology, and in particular to a multilayer structure of orally administered phenylalanine ammonia-lyase granules. Background Technology

[0002] Phenylketonuria (PKU) is a common inherited metabolic disorder caused by a deficiency of phenylalanine hydroxylase (PAH), which prevents the efficient conversion of phenylalanine to tyrosine, leading to the accumulation of phenylalanine in the blood. When phenylalanine levels are too high, it can cause irreversible damage to the nervous system, especially to the brain development of infants and young children, resulting in serious consequences such as intellectual disability and behavioral abnormalities. Therefore, the goal of PKU treatment is to lower phenylalanine levels in the body to prevent this neurological damage.

[0003] Currently, treatment for PKU primarily relies on a low-phenylalanine diet and enzyme replacement therapy. In enzyme replacement therapy, the commonly used exogenous enzyme is phenylalanine ammonia-lyase (PAL). PAL can convert phenylalanine into a non-toxic product through a non-human metabolic pathway, reducing phenylalanine absorption and thus lowering its concentration in the patient's body.

[0004] While injection therapy is an effective method, its drawbacks, such as frequent injections, poor patient compliance, and potential local side effects, limit its widespread application. In contrast, oral delivery of PAL, as a non-invasive treatment, offers higher patient compliance and convenience, making it particularly suitable for long-term treatment. However, as a protein enzyme, PAL faces several challenges during oral delivery: 1. The highly acidic environment of the stomach (pH approximately 1.5 to 3.5) rapidly inactivates most enzymes, significantly weakening their therapeutic effect; 2. In the small intestine, bile and other digestive enzymes (such as proteases) disrupt the enzyme's molecular structure, leading to reduced activity; 3. Rapid peristalsis and emptying of the small intestine quickly expel the drug-grade enzyme, resulting in a short effective retention time in the intestines and preventing it from fully exerting its effects.

[0005] Therefore, there is an urgent need to construct an innovative structure for oral phenylalanine ammonia-lyase granules that can effectively protect the stability of PAL in the gastrointestinal environment and prolong its retention time in the intestine, thereby improving its degradation efficiency of phenylalanine. Utility Model Content

[0006] This invention addresses the shortcomings of existing technologies by developing a multi-layered structure for oral phenylalanine ammonia-lyase (PAL) granules. Through the combined design of a core layer, a biomimetic protective layer, a smart response layer, and a targeted anchoring layer, it significantly enhances the stability and catalytic efficiency of PAL in the gastrointestinal tract and allows it to continue to function in the intestine through immobilization.

[0007] The technical solution to the technical problem solved by this utility model is as follows:

[0008] This application provides a multilayer structure for oral phenylalanine ammonia-lyase granules, including a core layer, a biomimetic protective layer covering the core layer, a smart response layer covering the biomimetic protective layer, and a targeting and anchoring layer covering the smart response layer.

[0009] The core layer is a porous structure used to encapsulate and immobilize PAL enzyme molecules.

[0010] As an improvement to the above scheme, the porous structure is made of MOFs material.

[0011] As an improvement to the above scheme, the MOF material is a zinc-based zeolite imidazole framework.

[0012] As an improvement to the above solution, the biomimetic protective layer is made of biomimetic silicon material.

[0013] As an improvement to the above scheme, the biomimetic silicon material is silicon dioxide nanoparticles.

[0014] As an improvement to the above solution, the smart response layer is made of a composite material of calcium alginate and protamine sulfate.

[0015] As an improvement to the above scheme, the smart response layer is made of calcium alginate and protamine in a ratio of 1:5 to 1:10.

[0016] As an improvement to the above scheme, the targeting anchoring layer is made of gut-specific binding molecules.

[0017] As an improvement to the above scheme, the intestinal-specific binding molecule is the RGD peptide.

[0018] As an improvement to the above scheme, the particle size of the core layer is 100-300 nanometers, the thickness of the biomimetic protective layer is 5-10 nanometers, the thickness of the smart response layer is 10-15 nanometers, and the thickness of the targeting and anchoring layer is 5-10 nanometers.

[0019] Compared with existing technologies, the above solution has the following advantages or beneficial effects:

[0020] This application employs a core layer to immobilize PAL, forming a physical barrier to prevent its inactivation in the gastrointestinal environment. A biomimetic protective layer provides mechanical strength and a chemical barrier, effectively resisting gastric acid erosion. A pH-sensitive smart response layer contracts in acidic environments to protect the core, while expanding in neutral environments, increasing pore size to promote substrate entry and product release, thus ensuring catalytic efficiency. A targeted anchoring layer enhances drug retention time in the intestine. This combined design significantly enhances the stability and catalytic efficiency of PAL in the gastrointestinal tract, giving it superior performance in oral delivery for treating diseases such as PKU. Attached Figure Description

[0021] The accompanying drawings are provided to further understand the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation thereof.

[0022] Figure 1 This is a schematic diagram of the multilayer structure of the oral phenylalanine ammonia-lyase granules in this embodiment.

[0023] Figure 2 This is a cross-sectional view of the multilayer structure of the oral phenylalanine ammonia-lyase granules in this embodiment.

[0024] In the diagram, 0 represents the enzyme molecule; 1 represents the core layer; 2 represents the biomimetic protective layer; 3 represents the intelligent response layer; and 4 represents the targeting and anchoring layer. Detailed Implementation

[0025] To clearly illustrate the technical features of this solution, the present invention will be described in detail below through specific embodiments and in conjunction with the accompanying drawings. The following disclosure provides many different embodiments or examples for implementing different structures of the present invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Furthermore, the present invention may repeat reference numerals and / or letters in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed.

[0026] See Figure 1 and 2 This embodiment provides a multilayer structure of oral phenylalanine ammonia-lyase (PAL) particles, including a core layer 1, a biomimetic protective layer 2 covering the core layer 1, a smart response layer 3 covering the biomimetic protective layer 2, and a targeting anchoring layer 4 covering the smart response layer 3.

[0027] The aforementioned core layer 1 is the core part of the PAL particle. It encapsulates the enzyme molecule O through a porous structure of metal-organic frameworks (MOFs), forming a physical barrier that effectively prevents the enzyme molecule O from being damaged by the external environment. This porous structure solves the problem of rapid enzyme inactivation in the gastrointestinal tract in existing technologies, allowing the enzyme molecule O to maintain its structural stability and activity, and remain effective in the gastrointestinal environment for a long time. Specifically, the MOF material is selected from materials with good biocompatibility and suitable particle size, with a particle size of 100-300 nanometers, and can be a zinc-based zeolite imidazole framework.

[0028] The aforementioned biomimetic protective layer 2, with a thickness of 5-10 nanometers, encapsulates the core layer 1 with a biomimetic silicon material, providing additional mechanical strength and chemical barrier. This protective layer effectively prevents the erosion of the core layer 1 by gastric acid and digestive juices, allowing PAL in the core layer 1 to safely pass through the stomach and ensure its function of degrading phenylalanine in the small intestine. Compared with traditional single-layer protective designs, this significantly enhances the protective effect of PAL during oral delivery. Specifically, the biomimetic silicon material can be made of silica nanoparticles to ensure the stability of the biomimetic protective layer 2.

[0029] The aforementioned smart response layer 3 is composed of a composite material of calcium alginate and protamine sulfate, exhibiting pH sensitivity and a thickness of 10-15 nanometers. Further, the smart response layer 3 is composed of calcium alginate and protamine sulfate in a ratio of 1:5 to 1:10. Based on the inherent properties of this composite material in the prior art, it can possess the following functions: In the acidic environment of the stomach, the structure of the smart response layer contracts, preventing gastric juice from damaging the PAL particles; after entering the intestines, under the stimulation of a neutral environment, the structure of the smart response layer expands, the pores enlarge, promoting the entry of phenylalanine into the enzyme's reaction site and ensuring the smooth excretion of the product.

[0030] The aforementioned targeting and anchoring layer 4 is made of gut-specific binding molecules and has a thickness of 5-10 nanometers. Based on the inherent properties of this material in existing technologies, the gut-specific binding molecules can bind to small intestinal epithelial cells, significantly prolonging the drug's residence time in the small intestine. In in vitro experiments simulating intestinal peristalsis, drug particles with the targeting and anchoring layer 4 exhibited a residence time three times longer than unanchored particles, extending from 2 hours to 6 hours, significantly enhancing the degradation effect of PAL. Specifically, the gut-specific binding molecules can be RGD peptides or gut-specific glycans, ensuring strong binding affinity between the particles and intestinal epithelial cells.

[0031] In in vitro simulation experiments, PAL particles coated with core layer 1 and biomimetic protective layer 2 maintained 50% activity in an acidic environment, while uncoated PAL particles quickly became fully active. These results indicate that the design of core layer 1 and biomimetic protective layer 2 significantly improves the stability and activity of PAL particles in vivo.

[0032] In a simulated gastrointestinal digestion process, PAL particles with the addition of the intelligent response layer 3 retained 80% of their enzyme activity, while PAL particles coated only with the core layer 1 and the biomimetic protective layer 2 retained only 30% of their enzyme activity. This indicates that the intelligent response layer 3 effectively prevents the gastrointestinal fluid from damaging the enzyme and ensures the catalytic activity of the PAL enzyme.

[0033] Retention effect experiment of targeted anchoring layer 4: Using an in vitro experiment simulating small intestinal peristalsis, the average retention time of particles containing targeted anchoring layer 4 in the small intestine was 6 hours, which was 3 times longer than that of particles without anchoring layer, thus enhancing local efficacy.

[0034] Although the specific embodiments of the utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the utility model. Based on the technical solution of the utility model, various modifications or variations that can be made by those skilled in the art without creative effort are still within the scope of protection of the utility model.

Claims

1. A multi-layer structure of an oral phenylalanine ammonia-lyase particle, characterized by: It includes a kernel layer, a biomimetic protective layer covering the kernel layer, an intelligent response layer covering the biomimetic protective layer, and a targeting and anchoring layer covering the intelligent response layer; The core layer is a porous structure used to encapsulate and immobilize phenylalanine ammonia-lyase molecules.

2. A multi-layered structure of a phenylalanine ammonia-lyase granule for oral administration according to claim 1, characterized in that: The porous structure is made of MOFs material.

3. The multilayer structure of an oral phenylalanine ammonia-lyase granule according to claim 2, characterized in that: The MOFs material is a zinc-based zeolite imidazole framework.

4. The multilayer structure of an oral phenylalanine ammonia-lyase granule according to claim 1, characterized in that: The biomimetic protective layer is made of biomimetic silicon material.

5. The multilayer structure of an oral phenylalanine ammonia-lyase granule according to claim 4, characterized in that: The biomimetic silicon material is silicon dioxide nanoparticles.

6. The multilayer structure of an oral phenylalanine ammonia-lyase granule according to claim 1, characterized in that: The smart response layer is composed of calcium alginate and protamine sulfate.

7. The multilayer structure of an oral phenylalanine ammonia-lyase granule according to claim 1, characterized in that: The targeting anchoring layer is composed of gut-specific binding molecules.

8. The multilayer structure of an oral phenylalanine ammonia-lyase granule according to claim 7, characterized in that: The gut-specific binding molecule is a gut-specific glycan.

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