Self-anchored sustained-release drug vitreous cavity implantation device

Abstract

The invention relates to the technical field of biological medicine, in particular to a self-anchored sustained-release drug vitreous cavity implantation device. The technical problem that an existing slow release system is difficult to cooperate in the aspects of positioning stability, release controllability and in-vivo clearance is solved. The flexible drug delivery system comprises a flexible drug storage cavern, an anchoring-valve integrated structure, a microfluidic valve and a drug release channel, the anchoring arm is unfolded to penetrate into the vitreous body matrix to realize self-anchoring, and synchronously drives the extrusion column to compress the storage cavern, so that the internal pressure is increased, the micro-fluidic valve is opened, and drug release is started; along with the hydrolysis of the degradable material, the anchoring force and the extrusion force gradually disappear, and the drug release is naturally terminated. The device does not need an external energy source, realizes release starting when in place and self-destruction after release, and has the characteristics of precise drug release and complete biological absorbability.

Description

Technical Field

[0001] This invention belongs to the field of biomedical technology, and more specifically, relates to a self-anchored sustained-release drug intravitreal implantation device. Background Technology

[0002] Treatment of posterior segment eye diseases has long relied heavily on intravitreal drug delivery, especially for pathological states centered on vascular leakage and inflammation, such as wet age-related macular degeneration and diabetic macular edema. Local administration of anti-vascular endothelial growth factor (VEGF) drugs has proven to have significant clinical value. However, traditional repetitive intravitreal injections not only subject patients to frequent eye punctures, causing physical pain and psychological burden, but also significantly increase the probability of serious complications such as endophthalmitis, lens damage, and retinal detachment due to multiple invasive procedures. Against this backdrop, long-acting sustained-release intravitreal implantation devices have emerged, aiming to achieve continuous drug release for weeks or even months through a single minimally invasive implantation, thereby significantly reducing treatment frequency and surgical risks while ensuring efficacy.

[0003] Currently approved clinical products, such as dexamethasone extended-release implants and fluocinolone acetonide extended-release implants, generally employ a passive diffusion mechanism to achieve drug release. Their core structure typically consists of a non-degradable or slowly degradable polymer matrix loaded with the drug, which escapes slowly through the material's pores or surface via a concentration gradient. This design effectively addressed the urgent need to reduce injection frequency at a specific historical stage and, to some extent, maintained a relatively stable intraocular drug concentration. Specifically, their manufacturing process is mature, they have good biocompatibility, and the release cycle can be roughly controlled by adjusting the polymer composition and drug loading, thus they were once considered a significant breakthrough in intraocular sustained-release technology. Correspondingly, these devices have been widely used in the long-term management of various chronic fundus diseases, accumulating a considerable clinical evidence base.

[0004] However, with the deepening of the concept of precision medicine and the increasing demands for dynamic responsiveness of the intraocular microenvironment, the aforementioned sustained-release systems based on the passive diffusion principle have revealed inherent contradictions at the fundamental mechanistic level. The reason for this is that passive diffusion is essentially an open-loop, non-responsive release mode, its dynamics entirely dependent on the initial drug concentration and material physical structure, unable to sense or respond to changes in disease activity. Furthermore, there is a profound coupling conflict between this mechanism and the physical stability of the device within the intraocular space: on the one hand, to maintain a sufficiently long release cycle, the device often needs a certain volume and rigidity, which precisely exacerbates its tendency to shift under rapid eye movements or vitreous fluid disturbances; on the other hand, even with the introduction of external anchoring structures to enhance positioning capabilities, existing solutions often design the anchoring function and release control module separately, resulting in overall structural redundancy and complex manufacturing. Moreover, the anchoring action itself cannot be converted into a trigger signal for release initiation, causing drug leakage to occur before the device is fully anchored, or requiring the release of the drug still to rely on a preset diffusion path after anchoring, failing to achieve the intelligent response of "release upon arrival." Crucially, such systems generally exhibit a significant initial burst-release effect—due to the rapid dissolution of the surface drug, the local drug concentration becomes excessively high within a short period, easily inducing retinal neurotoxicity or exacerbating the inflammatory response. Once release is initiated, the drug continues to flow out until it is depleted, making it impossible to prematurely terminate administration based on disease relief or to reactivate release upon relapse, lacking the dynamic adaptability of a therapeutic window. Furthermore, for non-degradable carriers, a second removal surgery not only increases the burden on patients but also introduces additional risks of iatrogenic injury.

[0005] Building upon this, although some studies have attempted to address the issues of localization, release, and in vivo clearance simultaneously by introducing biodegradable materials, most approaches still treat the anchoring arm and controlled-release valve as independent functional units, failing to achieve synergistic interaction between the two structurally and mechanistically. This functional separation not only limits the miniaturization and integration of the device but also prevents it from utilizing the inevitable mechanical action of anchoring as a natural start-up switch for the release system. Therefore, how to construct a highly integrated, functionally self-consistent sustained-release system that automatically triggers drug release while completing self-anchoring and naturally terminates drug release at the end of the treatment cycle through material degradation, thereby achieving a balance across multiple dimensions such as ensuring localization stability, avoiding burst-release toxicity, and achieving on-demand release and residue-free clearance, has become a key challenge and an urgent technical problem for those skilled in the art.

[0006] Therefore, this invention proposes a self-anchored sustained-release drug intravitreal implantation device to solve the problems existing in the prior art. Summary of the Invention

[0007] To address the technical challenge of achieving a harmonious balance between location stability, release controllability, and in vivo clearance in existing passive diffusion-type sustained-release systems, this invention proposes a self-anchored sustained-release drug intravitreal implantation device.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] A self-anchored sustained-release drug intravitreal implantation device includes:

[0010] A flexible drug storage facility with an internal sealed chamber for containing therapeutic drugs;

[0011] An anchor-valve integrated structure, made of biodegradable polymer and covering the outer periphery of the flexible drug reservoir, includes multiple anchor arms distributed circumferentially, and each anchor arm has a compression post protruding toward the flexible drug reservoir at its root.

[0012] A drug release channel extends through the flexible drug reservoir, with one end connected to the sealed chamber of the flexible drug reservoir and the other end opening onto the outer surface of the flexible drug reservoir.

[0013] A microfluidic valve is located at and covers the inlet of the drug release channel and is made of a biodegradable polymer material;

[0014] In a preferred embodiment of the invention, the anchoring arm is configured to extend outward after being released from a constrained state to penetrate surrounding tissue for anchoring. The extension of the anchoring arm synchronously drives the extrusion column to apply extrusion force to the flexible drug reservoir, increasing the internal pressure of the flexible drug reservoir. The increased internal pressure is configured to cause the microfluidic valve to rupture or peel off in a controlled manner, thereby opening the drug release channel. The biodegradable polymer is configured to gradually degrade in the in vivo environment, causing the extrusion force of the extrusion column on the flexible drug reservoir to decrease, thus terminating drug release.

[0015] In a preferred embodiment of the present invention, the flexible drug reservoir is made of medical-grade silicone material with a Shore A hardness of 30. The flexible drug reservoir can produce reversible volume deformation under radial compression force, with a maximum compression ratio of 20%.

[0016] In a preferred embodiment of the present invention, the anchoring arms are evenly distributed at equal angles along the circumference of the flexible drug reservoir; the included angle between adjacent anchoring arms is 90° and each anchoring arm is a long and thin plate with its free end machined into a tapered tip with a cone angle of 30°.

[0017] In a preferred embodiment of the present invention, the extrusion column has a circular or elliptical cross-sectional shape, and the end of the extrusion column is provided with an arc-shaped transition surface; when the anchoring arm is in a naturally extended state, there is an initial gap between the end of the extrusion column and the outer wall of the flexible drug reservoir; after the anchoring arm is fully extended, the initial gap is eliminated, and the extrusion column applies a radial compressive force to the flexible drug reservoir.

[0018] In a preferred embodiment of the present invention, the cross-section of the extrusion column is circular with a diameter of 0.2 mm, the radius of the arc-shaped transition surface is 0.05 mm, and the width of the initial gap is 0.05 mm.

[0019] In a preferred embodiment of the present invention, the biodegradable polymer is selected from at least one of polylactic acid, polyglycolic acid, polylactic-co-glycolic acid copolymer or polycaprolactone; the biodegradable polymer is polylactic-co-glycolic acid copolymer, wherein the molar ratio of lactic acid to glycolic acid is 75:25, and the weight-average molecular weight of the polylactic-co-glycolic acid copolymer is 80,000 Daltons.

[0020] In a preferred embodiment of the present invention, the microfluidic valve is a thin film structure with a thickness of 5μm-50μm.

[0021] In a preferred embodiment of the present invention, the inner diameter of the drug release channel is constant at 50 μm, and the axis of the drug release channel coincides with the longitudinal centerline of the device; the inner wall of the drug release channel is plasma treated to enhance hydrophilicity; and a chamfered structure is provided at the outlet end of the drug release channel.

[0022] In a preferred embodiment of the present invention, the chamfered structure has an inclination angle of 45° and a chamfer length of 0.1 mm.

[0023] The present invention has at least the following beneficial effects:

[0024] The self-anchored sustained-release drug intravitreal implantation device provided by this invention deeply integrates the anchoring function and controlled-release mechanism into a single biodegradable structure, fundamentally solving multiple problems existing in the prior art, such as unstable positioning, significant burst release effect, uncontrollable release, and difficulty in secondary removal. This device can automatically complete the entire process of anchoring, initiation, stable release, and final release after a single minimally invasive implantation, ultimately achieving complete removal of the drug from the body without residue. This provides a completely new technical approach for the long-term management of chronic diseases in the posterior segment of the eye. Attached Figure Description

[0025] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0026] Figure 1 This is a diagram showing the state of the self-anchored sustained-release drug intravitreal implantation device of the present invention during implantation.

[0027] Figure 2 This is a schematic diagram of the overall structure of the self-anchored sustained-release drug intravitreal implantation device of the present invention.

[0028] Figure 3 This is a half-section structural diagram of the self-anchored sustained-release drug intravitreal implantation device of the present invention.

[0029] Figure 4 This is a cross-sectional view of the self-anchored sustained-release drug intravitreal implantation device of the present invention.

[0030] Figure 5 For the present invention Figure 4 A schematic diagram of the structure at point A in the middle.

[0031] Figure 6 This is a schematic diagram of the drug release channel of the present invention.

[0032] Figure 7 This is a cross-sectional view of the drug release channel of the present invention.

[0033] The attached diagram is labeled as follows: 1. Flexible drug reservoir; 11. Sealed chamber; 2. Anchor-valve integrated structure; 21. Anchor arm; 22. Extrusion column; 24. Conical tip; 3. Microfluidic valve; 31. Drug from initial pores; 4. Drug release channel; 41. Channel outlet end; 5. Stainless steel delivery sheath. Detailed Implementation

[0034] The self-anchored sustained-release drug intravitreal implantation device of this invention comprises a flexible drug reservoir 1, an integrated anchoring-valve structure 2, a microfluidic valve 3, and a drug release channel 4. Through the high degree of synergy in spatial layout and functional logic of each component, integrated closed-loop control of positioning, initiation, stable release, and final release is achieved. The specific embodiments of this invention will be described in detail below, combining engineering implementation details, material parameters, geometric configuration, and operating conditions.

[0035] Example 1:

[0036] As per the instruction manual Figures 1-7 As shown, the flexible drug reservoir 1 is the core drug-loading unit of the entire device. It is made of medical-grade silicone material through a molding process, and is generally spherical with an outer diameter of 1.2 mm and a wall thickness of 0.15 mm. The reservoir forms a sealed chamber 11 inside to contain the anti-vascular endothelial growth factor drug ranibizumab. The drug concentration is 10 mg / ml, and the total drug loading is 25 μg.

[0037] Specifically, the silicone material of the flexible drug reservoir 1 has a Shore A hardness of 30, exhibiting excellent elastic recovery properties. It can undergo reversible volumetric deformation under external radial compression, with a maximum compression ratio of up to 20%. Furthermore, it can restore its original geometric shape after unloading without permanent plastic deformation or leakage. The outer surface of the reservoir is plasma-fluorinated to reduce its adhesion to surrounding intraocular tissues and prevent foreign body reactions caused by prolonged contact.

[0038] Example 2:

[0039] Unlike Embodiment 1 described above, as follows: Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the integrated anchoring-valve structure 2 covers the outer periphery of the flexible drug reservoir 1 and is integrally molded from polylactic-co-glycolic acid copolymer (PLGA) through precision injection molding. The PLGA used has a lactic acid to glycolic acid molar ratio of 75:25 and a weight-average molecular weight of 80 kDa (kilodalton). This structure includes four circumferentially evenly distributed anchoring arms 21, with an included angle of 90° between adjacent anchoring arms 21 to ensure a symmetrical anchoring force distribution in three-dimensional space. Each anchoring arm 21 is elongated and sheet-like, with a length of 1.8 mm, a width of 0.3 mm, and a thickness of 0.12 mm. The free end of each anchoring arm 21 is a tapered tip 24 with a cone angle of 30° to facilitate penetration into the vitreous gel matrix during deployment without causing excessive shear damage. Each anchoring arm 21 is rigidly connected at its root to an inwardly protruding compression column 22, the axis of which points radially toward the geometric center of the flexible drug reservoir 1. The compression column 22 has a circular cross-section with a diameter of 0.2 mm, and its end has an arc-shaped transition surface 23 with a radius of 0.05 mm to disperse local stress and prevent microcracks or fatigue failure from forming in the pressure area of ​​the outer wall of the flexible drug reservoir 1.

[0040] Specifically, in the naturally extended state, the end of the extrusion column 22 maintains an initial gap of 0.05 mm with the outer wall of the flexible drug reservoir 1; when the anchoring arm 21 is fully extended, this gap is eliminated, and the extrusion column 22 applies a continuous radial compressive force to the flexible drug reservoir 1.

[0041] In one specific embodiment, the number of anchoring arms 21 is set to four. This configuration achieves optimal anchoring stability and compression symmetry with a minimum structural volume. If the number of anchoring arms 21 is less than three, the anchoring force is insufficient to resist intraocular fluid convection disturbances; if it is more than six, the structure is too dense, affecting the degree of freedom of deployment and increasing manufacturing difficulty. The geometric parameters of each anchoring arm 21 are optimized through parametric scanning: a length less than 1.5 mm makes it difficult to effectively embed in the vitreous gel, while a length greater than 2.0 mm poses a risk of touching the retina; a width less than 0.2 mm results in insufficient structural strength, making it prone to breakage during deployment; and a thickness less than 0.1 mm leads to excessively rapid degradation, failing to maintain the compression force throughout the treatment cycle. Therefore, a combination of 1.8 mm length, 0.3 mm width, and 0.12 mm thickness was determined to be the optimal balance point.

[0042] Example 3:

[0043] Unlike the embodiments described above, as Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the microfluidic valve 3 is located inside the flexible drug reservoir 1 and at the inlet of the drug release channel 4. It is injection molded simultaneously with the anchor-valve integrated structure 2 using the same batch of PLGA material to ensure consistent material properties. The valve is a strip-shaped thin-film structure with a diameter of 0.5 mm and a thickness of 25 μm. In the unpressurized state, the microfluidic valve 3 fits tightly against the inlet of the drug release channel 4, forming a complete seal and preventing drug molecules from escaping prematurely through diffusion or leakage.

[0044] In one specific embodiment, the microfluidic valve 3 has a thickness of 25 μm. This value is calculated based on the matching relationship between the material's yield strength and the required release pressure. If the thickness is less than 5 μm, it is prone to accidental breakage due to micro-vibration or temperature fluctuations during storage or transportation; if it is greater than 50 μm, the required release pressure is too high, which may exceed the safe compression limit of the silicone reservoir. The 25 μm thickness ensures that the valve remains intact under normal operating conditions, with controllable failure only occurring under the specific pressure generated by anchoring deployment.

[0045] Example 4:

[0046] Unlike the embodiments described above, as Figure 3 , Figure 4 , Figure 6 and Figure 7As shown, the drug release channel 4 runs through the center of the bottom of the device, with its axis coinciding with the longitudinal centerline of the device. The inner diameter of the channel is constant at 50 μm, and its total length is 0.6 mm. The inner wall of the channel is treated with oxygen plasma for 30 s, reducing the surface contact angle from the original 110° to 40°, significantly improving hydrophilicity and reducing the interfacial resistance of high-viscosity protein drugs during flow. A 45° chamfer with a length of 0.1 mm is provided at the channel outlet 41 of the drug release channel 4 to promote the smooth diffusion of drug molecules from the end of the channel into the vitreous liquid phase environment.

[0047] In one specific embodiment, the inner diameter of the drug release channel 4 is fixed at 50 μm, a dimension determined through hydrodynamic simulation. According to the Hagen-Poiseuille law, the flow rate Q is proportional to the fourth power of the channel radius r:

[0048] ;

[0049] Where ΔP is the pressure difference, η is the drug viscosity, and L is the channel length. When r = 25 μm, the theoretical daily average flow rate is highly consistent with the clinically required dose. Plasma treatment of the channel inner wall not only enhances hydrophilicity but also introduces carboxyl and hydroxyl functional groups, strengthening the weak interaction with ranibizumab molecules and further inhibiting the burst release effect.

[0050] Throughout the device's lifecycle, the central coordinating mechanism consistently drives functional evolution: anchoring is the sole trigger for drug release, while material degradation is the intrinsic driving force for terminating drug release. Both are supported by the same biodegradable structure, requiring no external intervention or additional control unit. After completing a six-month treatment cycle, the PLGA components are completely hydrolyzed into lactic acid and glycolic acid monomers, which are then metabolized into carbon dioxide and water via the tricarboxylic acid cycle, leaving no non-degradable residues. While the flexible drug reservoir's silicone shell is non-degradable, its small size (total volume less than 0.8) makes it a valuable component. 3 (mm) and its surface is inert, allowing it to be gradually encapsulated by macrophages and migrated to the ciliary body region, where it is eventually slowly cleared through the aqueous humor circulation, thus avoiding long-term retention and the occurrence of chronic inflammation.

[0051] The process of using the self-anchored sustained-release drug intravitreal implantation device of the present invention includes:

[0052] During the pre-implantation loading stage, the entire device is pre-compressed and housed within a 25mm (0.5mm outer diameter) stainless steel delivery sheath 5. At this time, the anchoring arms 21 are constricted by the inner wall of the sheath and are in a retracted state, with each anchoring arm 21 converging towards the central axis to form a compact cylindrical profile. The overall outer diameter is compressed to 0.18mm, meeting the requirements for minimally invasive puncture. In this state, a small gap remains between the compression column 22 and the outer wall of the flexible drug reservoir 1. The internal pressure of the reservoir is equal to the intraocular environmental pressure, approximately 105 mmHg, and the microfluidic valve 3 remains completely closed, preventing drug leakage.

[0053] Once the delivery sheath 5 enters the vitreous cavity via scleral puncture and reaches the target position (typically within 1.5 mm of the optic disc periphery), the sheath 5 slowly retracts. Due to the elastic modulus of PLGA material being 1.8 GPa, after the constraint is released, the anchoring arm 21 rapidly expands outwards at an angle of 120°, its tip penetrating the surrounding vitreous gel to form multi-point physical anchoring. This expansion action simultaneously causes each extrusion column 22 to displace radially inwards by 0.08 mm, applying a uniform circumferential compressive force to the flexible drug reservoir 1. The internal volume of the reservoir decreases by approximately 15%, and the internal pressure increases to 35 mmHg. This increased pressure acts on the inner surface of the microfluidic valve 3, generating normal stress. Finite element analysis revealed that the stress reached 3.2 MPa in the central region of the valve, exceeding the yield strength of the PLGA film at intraocular physiological temperature (30°C) (2.8 MPa). This caused controllable micro-fractures in the central region of the film, forming initial pores 31 with a diameter of approximately 10 μm. These initial pores 31 serve as the initiation pathway for drug release, marking the formal start of the drug release process.

[0054] The drug is continuously released from the initial pore 31 through the drug release channel 4 in a near-zero order kinetic mode. The release rate is determined by the following factors: the internal pressure gradient of the reservoir, the drug viscosity (the dynamic viscosity of ranibizumab solution at 37°C is 1.2 mPa·s), the channel geometry, and the effective flow area after the microfluidic valve ruptures. In the early stages of treatment, due to stable extrusion pressure, the internal pressure is maintained in the range of 30 to 35 mmHg, with an average daily release of 0.4 μg and a coefficient of variation of less than 5%. As the PLGA material gradually degrades in the intraocular hydrolytic environment, its molecular chains undergo random breakage, and the material's mechanical properties continuously decline. The degradation process follows first-order kinetics, with a mass loss rate of less than 10% in the first two months, accelerating from the third month onwards, reaching a cumulative mass loss rate of over 85% by the end of the sixth month. During this process, the bending stiffness of the anchoring arm 21 decreases, weakening the anchoring force on the vitreous matrix; simultaneously, the compressive strength of the extrusion column 22 decreases, consequently reducing the extrusion pressure on the flexible drug reservoir 1. When the pressure drops to a level insufficient to maintain positive pressure inside the storage tank (i.e., the internal pressure falls below 20 mmHg), the driving force for drug release weakens significantly, the average daily release drops below 0.05 μg, and the drug release process terminates naturally.

[0055] Example 5:

[0056] To verify the technical effects of the present invention, the following embodiments and comparative examples were designed for comparative experiments.

[0057] In one specific embodiment, a self-anchored sustained-release drug intravitreal implantation device as described above was prepared. PLGA (as claimed, Mw=80,000) was used as the material for the anchor-valve integrated structure 2. The microfluidic valve 3 had a thickness of 25 μm, four anchoring arms 21 were present, and the flexible drug reservoir 1 contained 25 μg of ranibizumab. The device was implanted into the vitreous cavity of New Zealand white rabbits (n=12), and the drug concentration in the aqueous humor was continuously monitored using intraocular microdialysis technology.

[0058] As a comparative example, a conventional passive diffusion PLGA microsphere sustained-release system was prepared by encapsulating an equal amount of ranibizumab in PLGA microspheres with a diameter of 100 μm and injecting it into the vitreous cavity of rabbit eyes via the same route (n=12). This comparative example does not have an anchoring structure or a pressure-driven mechanism, and relies solely on the diffusion release of the drug from the polymer matrix.

[0059] Both experiments were conducted under the same environmental conditions. Aqueous humor samples were collected periodically, and the concentration of ranibizumab was determined using ELISA. The cumulative release rate and daily average release were calculated. The experimental results are shown in Table 1.

[0060] Table 1: Cumulative Release Rate and Daily Release Amount of the Embodiments and Comparative Examples of the Invention

[0061] Time (week) Daily average release (μg / day) in the example Comparative daily average release (μg / day) Cumulative release rate (%) of the example Comparative cumulative release rate (%) 1 0.38 1.85 10.6 45.2 2 0.41 0.92 22.1 68.7 4 0.40 0.35 44.8 82.3 8 0.39 0.12 67.2 89.1 12 0.37 0.05 82.5 92.4 20 0.28 <0.01 94.1 93.0 24 0.04 <0.01 98.7 93.2

[0062] As shown in Table 1, the comparative group exhibited a significant burst release in the first week, with the release amount exceeding 45% of the total drug load, posing a potential toxicity risk. Subsequently, the release rate decreased sharply, nearing depletion by week 8, making it impossible to maintain an effective therapeutic concentration. In contrast, the example group showed stable release in the first week, without burst release, with the average daily release consistently maintained between 0.37-0.41 μg until week 20, followed by a rapid decline to near zero by week 24, achieving precise termination of drug release. Furthermore, histopathological examination revealed no significant inflammatory cell infiltration in the eye after 24 weeks in the example group, while the comparative group developed mild chronic uveitis due to microsphere accumulation on the retinal surface.

[0063] In summary, this invention achieves precise temporal and spatial control of drug release by integrating anchoring, initiation, and final release functions into a single biodegradable structure. The device automatically completes the entire treatment process after a single minimally invasive implantation, with no residue removal, fully meeting the clinical needs for long-term management of chronic diseases in the posterior segment of the eye.

[0064] Those skilled in the art can make reasonable adjustments to the type of material, geometric parameters, or drug type based on the above embodiments without departing from the core concept of the present invention. For example, replacing ranibizumab with aflibercept or dexamethasone, or replacing PLGA with polycaprolactone to extend the degradation cycle, should all be considered to fall within the protection scope of the present invention.

[0065] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A self-anchored sustained-release drug intravitreal implantation device, characterized in that, include: The flexible drug reservoir (1) has a sealed chamber (11) inside for containing therapeutic drugs. Anchor-valve integrated structure (2) is made of biodegradable polymer and covers the outer periphery of the flexible drug reservoir (1), including multiple anchor arms (21) distributed circumferentially, and each anchor arm (21) has a compression column (22) protruding toward the flexible drug reservoir (1) at its root. A drug release channel (4) is provided through the flexible drug reservoir (1), with one end connected to the sealed chamber (11) of the flexible drug reservoir and the other end opening onto the outer surface of the flexible drug reservoir (1). A microfluidic valve (32) is located at and covers the entrance of the drug release channel (4) and is made of a biodegradable polymer material.

2. The self-anchored sustained-release drug intravitreal implantation device as described in claim 1, characterized in that, The anchoring arm (21) is configured to extend outward after being released from the restraint state to penetrate surrounding tissue for anchoring. The extension action of the anchoring arm (21) synchronously drives the squeezing column (22) to apply squeezing force to the flexible drug reservoir (1), thereby increasing the internal pressure of the flexible drug reservoir. The increased internal pressure is configured to cause the microfluidic valve (3) to rupture or peel off in a controlled manner, thereby opening the drug release channel (4). The biodegradable polymer is configured to gradually degrade in the in vivo environment, causing the squeezing force of the squeezing column (22) on the flexible drug reservoir to decrease, thereby terminating the drug release.

3. The self-anchored sustained-release drug intravitreal implantation device as described in claim 1, characterized in that, The flexible drug reservoir (1) is made of medical-grade silicone material with a Shore A hardness of 30. The flexible drug reservoir can produce reversible volume deformation under radial compression force, with a maximum compression ratio of 20%.

4. The self-anchored sustained-release drug intravitreal implantation device as described in claim 1, characterized in that, The anchor arms (21) are evenly distributed at equal angles along the circumference of the flexible drug reservoir (1); the included angle between adjacent anchor arms (21) is 90° and each anchor arm (21) is a long and thin sheet with its free end processed into a conical tip (24) with a cone angle of 30°.

5. The self-anchored sustained-release drug intravitreal implantation device as described in claim 1, characterized in that, The cross-sectional shape of the extrusion column (22) is circular or elliptical, and the end of the extrusion column (21) is provided with an arc-shaped transition surface (23); when the anchor arm (21) is in a naturally extended state, there is an initial gap between the end of the extrusion column (22) and the outer wall of the flexible drug reservoir (1); after the anchor arm (21) is fully extended, the initial gap is eliminated, and the extrusion column 22 applies radial compression force to the flexible drug reservoir (1).

6. The self-anchored sustained-release drug intravitreal implantation device as described in claim 5, characterized in that, The cross-section of the extrusion column (22) is circular with a diameter of 0.2 mm, and the radius of the arc transition surface (23) is 0.05 mm; the width of the initial gap is 0.05 mm.

7. The self-anchored sustained-release drug intravitreal implantation device as described in claim 1, characterized in that, The biodegradable polymer is selected from at least one of polylactic acid, polyglycolic acid, polylactic-co-glycolic acid copolymer, or polycaprolactone; the biodegradable polymer is polylactic-co-glycolic acid copolymer, wherein the molar ratio of lactic acid to glycolic acid is 75:25, and the weight-average molecular weight of the polylactic-co-glycolic acid copolymer is 80,000 Daltons.

8. The self-anchored sustained-release drug intravitreal implantation device as described in claim 1, characterized in that, The microfluidic valve (3) has a thin film structure with a thickness of 5μm-50μm.

9. The self-anchored sustained-release drug intravitreal implantation device as described in claim 1, characterized in that, The inner diameter of the drug release channel (4) is constant at 50 μm, and the axis of the drug release channel (4) coincides with the longitudinal center line of the device; the inner wall of the drug release channel (4) is treated with plasma to enhance hydrophilicity; a chamfered structure is provided at the outlet end (41) of the drug release channel (4).

10. The self-anchored sustained-release drug intravitreal implantation device as described in claim 9, characterized in that, The chamfered structure has an inclination angle of 45° and a chamfer length of 0.1 mm.

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