PRP composite gel, and injection system and injection method thereof

Abstract

The invention relates to the technical field of biomedical engineering and regenerative medicine, and particularly discloses PRP composite gel. Comprising a component A and a component B, wherein the component A comprises a temperature-sensitive block copolymer matrix, a component B and a component C, the temperature-sensitive block copolymer matrix is prepared from Pluronic F-127 (the mass fraction is 20-25%) and methacrylic anhydride gelatin (GelMA (the mass fraction is 5-8%), and the methylacryloylation degree of the GelMA is 60-70%; the functionalized magnetic nanoparticles are characterized in that RGD peptides (the grafting rate is greater than or equal to 0.5 mu g / mg) are grafted on the surfaces of superparamagnetic Fe3O4 coated SiO2 nanoparticles (the particle size is 50 + / -5nm, and the thickness of a SiO2 coating layer is 8-10nm), and the mass fraction is 0.05-0.1%; the invention further provides an injection system and an injection method. According to the invention, the temperature-sensitive gel, the magnetic targeting PRP and the electromagnetic synergistic injection system are organically combined, so that the synergistic unification of three seemingly contradictory technical requirements of'fine needle injection '(27G), 'instant gelation' (completed within 3 seconds) and'directional slow release 'is successfully realized, and a major breakthrough is made technically.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biomedical engineering and regenerative medicine, and particularly relates to a PRP composite gel, and an injection system and method thereof. BACKGROUND

[0002] At present, the PRP therapy of the traditional technology mainly has the following problems:

[0003] Injection blockage problem: the viscosity of PRP increases sharply (> 500 cP) after pre-activation, and a needle with a diameter of 21G or more is required, resulting in large tissue trauma;

[0004] Growth factor diffusion out of control: more than 70% of growth factors diffuse and inactivate in non-target areas;

[0005] Platelet activity loss: the shear force of injection causes a platelet activity loss rate of 30-40%;

[0006] Therefore, the current PRP therapy, the single-phase temperature-sensitive gel (such as pure Pluronic F-127) has a slow gelation speed (> 30 seconds) at body temperature, and is prone to post-injection migration; and the magnetic targeting system is mainly used for drug delivery (CN112107699A), and does not solve the contradiction between activity protection and immediate gelation in the PRP injection process. SUMMARY

[0007] To solve the above problems, the present application provides a PRP composite gel, and an injection system and method thereof; the following technical solutions are adopted:

[0008] A PRP composite gel, comprising component A and component B; wherein the component A comprises:

[0009] A temperature-sensitive block copolymer matrix composed of Pluronic F-127 (mass fraction 20-25%) and methacrylated gelatin (GelMA, mass fraction 5-8%), wherein the degree of methacrylation of GelMA is 60-70%;

[0010] Functionalized magnetic nanoparticles: superparamagnetic Fe3O4@SiO2 nanoparticles (particle size 50±5 nm, SiO2 coating layer thickness 8-10 nm) grafted with RGD peptide (grafting rate ≥0.5 μg / mg) on the surface, mass fraction 0.05-0.1%;

[0011] The component B comprises:

[0012] PRP component: platelet concentration 4-6×10 5 platelets / μL, containing Ca 2+Activator (calcium chloride mass fraction 5-10%) and TGF-β3 (concentration 10-20 ng / mL); the gel presents sol state at 4-10 DEG C, viscosity <150 cP, and forms hydrogel with storage modulus 500-800 Pa at 33-37 DEG C through double crosslinking (physical temperature-sensitive crosslinking + light-induced crosslinking).

[0013] The present application successfully realizes the synergy and unification of three seemingly contradictory technical requirements of "fine needle injection" (27G), "instant gelation" (completed within 3 seconds), and "directional slow release", and makes a major breakthrough in technology. The core pain points such as inaccurate positioning and activity loss in current PRP treatment are effectively solved, and the efficiency of tissue repair can be significantly improved through experimental verification, which has a very high clinical application value. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 Part of the structure schematic diagram of the injection system of the present application is shown. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present application are described below in a clear and complete manner. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0016] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in other manners different from those described herein, and those skilled in the art can make similar generalizations without departing from the scope of the present application. Therefore, the present application is not limited to the specific embodiments disclosed below.

[0017] The PRP composite gel of the present application comprises: component A and component B; wherein the component A comprises:

[0018] Thermosensitive block copolymer matrix: composed of Pluronic F-127 (mass fraction 20-25%) and methacrylated gelatin (GelMA, mass fraction 5-8%), wherein the degree of methacrylation of GelMA is 60-70%;

[0019] Functionalized magnetic nanoparticles: superparamagnetic Fe3O4@SiO2 nanoparticles (particle size 50±5 nm, SiO2 coating layer thickness 8-10 nm) surface grafted with RGD peptide (grafting rate ≥0.5 μg / mg), mass fraction 0.05-0.1%;

[0020] The component B comprises:

[0021] PRP component: platelet concentration 4-6×10 5 platelets / μL, Ca 2+ activator (calcium chloride mass fraction 5-10%) and TGF-β3 (concentration 10-20 ng / mL);

[0022] The gel presents sol state at 4-10℃, viscosity <150 cP, and forms hydrogel with storage modulus 500-800 Pa at 33-37℃ through double cross-linking (physical temperature-sensitive cross-linking + light-induced cross-linking), and the cross-linking kinetics conforms to the formula:

[0023]

[0024] Wherein G0 is the equilibrium storage modulus, T is the characteristic relaxation time (2-3 s), and n is the cross-linking index (0.8-1.2).

[0025] The mass ratio of Pluronic F-127 to GelMA is 3:1-4:1, the average pore size of the composite hydrogel is 50-80 μm measured by dynamic light scattering, and the porosity is ≥85%. The saturation magnetization of the Fe3O4@SiO2 nanoparticles is 60-70 emu / g, the coercivity is <50 Oe, and the in vitro cytotoxicity grade is grade 1. The SiO2 shell thickness of the Fe3O4@SiO2 nanoparticles is 5-10 nm, and the Zeta potential is -20-30 mV.

[0026] As Figure 1 shown, it is a partial structure schematic diagram of the injection system of the application; the application also provides an injection system for PRP composite gel, which comprises:

[0027] Double-cavity pre-charged syringe: including A cavity and B cavity, wherein the A cavity is used for A component substance; the B cavity is used for loading B component substance;

[0028] Micro-mixing nozzle: spiral micro-channel structure;

[0029] The mixing efficiency conforms to the formula:

[0030] η=1-exp(-k·Re 0.7 ·Sc 0.3 )

[0031] Wherein, k=0.08, Re is the Reynolds number (50-150), Sc is the Schmidt number (1000-2000), and the mixing time is <0.5 s;

[0032] It also includes an adaptive electromagnetic needle: a micro electromagnetic coil integrated with a nickel-titanium alloy needle tube, which generates an alternating magnetic field (frequency 50 Hz) of 0.1-0.3 T.

[0033] Magnetic field control module: support static magnetic field intensity 0.3-1T continuous adjustable, magnetic field gradient is greater than or equal to 15T / m, magnetic field uniformity error is less than 5%.

[0034] The internal part of the micro-mixing nozzle is provided with a spiral micro-flow channel, and the length of the flow channel is 5-15mm;The adaptive electromagnetic needle head is a 25-30G nickel-titanium alloy needle tube, the number of turns of the micro electromagnetic coil is 60±5 turns, and the resistance is 2.5±0.2Ω.

[0035] The injection system also provides an injection method using the above-mentioned injection system, comprising:

[0036] Preparation before injection: place the syringe in a 4℃ environment to cool, keep the A and B phases in a separated state, and ensure the stability of the performance of each component;

[0037] Injection process: push the piston, and the A and B phase liquid flows through the micro-mixer to form a homogeneous low-temperature sol quickly, and then is injected into the target tissue through the needle head;

[0038] Control during injection: low-frequency alternating current (voltage 3-5V, frequency 50Hz) is supplied to the needle tip electromagnetic coil to generate an alternating magnetic field. The magnetic field promotes the uniform dispersion of magnetic particles in the gel, and effectively prevents the needle head from being blocked, ensuring the smooth progress of the injection process;

[0039] Release control after injection: the injected gel quickly solidifies under the action of body temperature, and at this time, an external focusing magnetic ring (patent accessory) is used to apply a directional static magnetic field with a strength of 0.5T. Under the action of the magnetic field, the magnetic particles carrying platelet-derived factors migrate to the target area in a controlled manner, realizing the controlled release of growth factors.

[0040] In the present application, composite gel injection is used: at a flow rate of 0.08-0.12mL / s, the temperature of the needle tip is maintained at 6-8℃ during the injection process;

[0041] During injection, an alternating magnetic field of 3V and 50Hz is applied, and the dispersion degree of magnetic particles is more than 90%, and the dispersion dynamics conforms to:

[0042]

[0043] Wherein, D0 is the maximum dispersion degree, and B is the magnetic field strength;

[0044] After injection, a directional static magnetic field (action time 6h) of 0.5T is applied, and the migration distance (d) of growth factors satisfies:

[0045]

[0046] Wherein, X is the magnetic susceptibility of the magnetic particle, (0.05-0.1emu / g·Oe), is the magnetic field gradient, η is the gel viscosity, and r is the magnetic particle radius.

[0047] wherein the static magnetic field is generated by a focusing magnetic ring. Specific embodiments:

[0049] Example 1: Orthopedic joint repair application

[0050] PRP preparation: Collect 30 mL of venous blood, centrifuge twice (1500 rpm x 10 min, 4000 rpm x 5 min) to obtain PRP with a platelet concentration of 5 x 10 5 / μL.

[0051] Gel preparation: A phase (Pluronic F-127 23% + methyl cellulose 2%) is dissolved at 4°C; B phase (PRP + Fe3O4@SiO2 nanoparticles 0.08% + calcium chloride 8%) is mixed at low temperature.

[0052] Injection operation: A double-lumen syringe is pre-cooled at 4°C, and 0.5 mL of the composite gel is injected at a flow rate of 0.1 mL / s under the guidance of an arthroscope, and a 3V alternating magnetic field is applied synchronously.

[0053] Postoperative magnetic control: An external magnetic ring (0.5T) is fixed for 6 hours, and MRI monitoring shows that the growth factor concentration in the damaged area is 2.8 times that in the non-target area.

[0054] Example 2: Medical skin anti-aging application

[0055] On the basis of Example 1, the formula is adjusted to Pluronic F-127 20% + methyl cellulose 1.5%, the magnetic particle concentration is 0.05%, a 30G needle is used for intradermal injection, and the postoperative magnetic control is 2 hours, which increases the amount of collagen synthesis by 2.3 times (immunohistochemical detection).

[0056] Therefore, in the present application:

[0057] Biphasic temperature-sensitive gel formula: Through the compounding of A phase (Pluronic F-127 / methyl cellulose) and B phase (PRP / magnetic particles), a low-viscosity fluid property of <100 cP at 4-10°C is achieved, and a hydrogel with G' > 500 Pa is solidified within 3 seconds above 33°C.

[0058] Electromagnetic synergistic injection system: A double-lumen syringe is used in combination with a spiral micro-mixing nozzle to achieve instant homogenization, a nickel-titanium alloy needle is integrated with a micro electromagnetic coil, and a 50Hz alternating magnetic field (3-5V) is used during injection to prevent magnetic particle agglomeration and blockage.

[0059] Fractional magnetic control release strategy: After injection, the magnetic particles are driven to migrate directionally by a 0.5T static magnetic field, which increases the local concentration of growth factors by 3.2±0.5 times, and the cartilage defect repair rate reaches 67%.

[0060] 1. Innovative "cold flow-hot condensation" dual-phase temperature-sensitive gel carrier: Breakthrough the performance limitations of traditional gels, achieve a clever balance between good flowability at low temperature and rapid gelation in body temperature environment.

[0061] 2. Efficient magnetic nanoparticle targeted activation and slow-release system: Precise regulation of growth factor release by magnetic nanoparticles significantly improves treatment effect.

[0062] 3. Low shear self-adaptive injection needle: effectively reduces the damage to platelet activity during injection, and reduces tissue trauma.

[0063] 4. Precise in vitro magnetic control directional release technology: Achieve efficient enrichment of growth factors in target tissue area, enhance treatment specificity.

[0064] Parameters Conventional PRP gel The present invention 27G needle injectability Not feasible 100% pass rate Post-injection platelet activity 62±8％ 94±3％ VEGF-targeted enrichment efficiency 1.0 fold 3.2 ± 0.5 fold Cartilage repair rate (8 weeks) 38％ 67％

[0065] Comparison of traditional PRP gel and the present invention

[0066] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can modify the technical solutions described in the foregoing embodiments or make equivalent replacements to some technical features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A PRP composite gel, characterized in that, include: Component A and component B; wherein, component A includes: Thermosensitive block copolymer matrix: composed of Pluronic F-127 (20-25% by mass) and methacrylic anhydride gelatin (GelMA, 5-8% by mass), wherein the degree of methacrylation of GelMA is 60-70%; Functionalized magnetic nanoparticles: Superparamagnetic Fe3O4@SiO2 nanoparticles (particle size 50±5nm, SiO2 coating thickness 8-10nm) with RGD peptide grafted on the surface (grafting rate ≥0.5μg / mg), mass fraction 0.05-0.1%. Component B includes: PRP components: Platelet concentration 4-6 × 10⁻⁶ 5 platelets / μL, containing Ca 2+ Activator (calcium chloride mass fraction 5-10%) and TGF-β3 (concentration 10-20 ng / mL); The gel exists in a sol state at 4-10℃ with a viscosity <150 cP. At 33-37℃, it forms a hydrogel with a storage modulus of 500-800 Pa through dual crosslinking (physical temperature-sensitive crosslinking + photo-initiated crosslinking). The crosslinking kinetics conform to the formula: Where G0 is the equilibrium energy storage modulus, T is the characteristic relaxation time (2-3s), and n is the crosslinking index (0.8-1.2).

2. The PRP composite gel as described in claim 1, characterized in that, The mass ratio of Pluronic F-127 to GelMA is 3:1-4:

1. The average pore size of the composite hydrogel, as measured by dynamic light scattering, is 50-80 μm, and the porosity is ≥85%.

3. The PRP composite gel as described in claim 1, characterized in that, The Fe3O4@SiO2 nanoparticles have a saturation magnetization of 60-70 emu / g, a coercivity of <50 Oe, and an in vitro cytotoxicity level of 1.

4. The PRP composite gel as described in claim 1, characterized in that, The SiO2 shell thickness of the Fe3O4@SiO2 nanoparticles is 5-10 nm, and the Zeta potential is -20 to 30 mV.

5. An injection system using the PRP composite gel as described in claim 1, characterized in that, The injection system includes: Dual-chamber pre-filled syringe: includes chamber A and chamber B, where chamber A is used for component A and chamber B is used to load component B. Micro-mixing nozzle: spiral microchannel structure; Mixing efficiency conforms to the formula: Where k = 0.08, Re is the Reynolds number (50-150), Sc is the Schmidt number (1000-2000), and the mixing time is < 0.5 s; It also includes an adaptive electromagnetic needle: a nickel-titanium alloy needle tube with an integrated miniature electromagnetic coil that generates an alternating magnetic field of 0.1-0.3T (frequency 50Hz); Magnetic field control module: Supports continuously adjustable static magnetic field strength from 0.3-1T, magnetic field gradient ≥15T / m, and magnetic field uniformity error <5%.

6. The injection system according to claim 5, characterized in that, The micro-mixing nozzle has a spiral microchannel inside, with a channel length of 5-15mm.

7. The injection system according to claim 5, characterized in that, The adaptive electromagnetic needle is a 25-30G nickel-titanium alloy needle tube, and the miniature electromagnetic coil has 60±5 turns and a resistance of 2.5±0.2Ω.

8. An injection method using the injection system as described in claim 5, characterized in that, The injection method includes: Pre-injection preparation: Place the syringe in a 4°C environment to cool it, so that phases A and B remain separated and the performance of each component is stable; Injection process: Pushing the piston, the A and B phase liquids flow through the micro mixer, rapidly forming a homogeneous low-temperature sol, which is then injected into the target tissue through the needle; Injection control: Low-frequency alternating current (3-5V, 50Hz) is applied to the electromagnetic coil at the needle tip to generate an alternating magnetic field. This magnetic field promotes the uniform dispersion of magnetic particles within the gel and effectively prevents needle clogging, ensuring a smooth injection process. Post-injection release control: The injected gel rapidly solidifies at body temperature. At this point, an external focusing magnetic ring (patent appendix) applies a directional static magnetic field with an intensity of 0.5T. Under the influence of the magnetic field, magnetic particles carry platelet-derived factors and migrate directionally to the target area, achieving controlled and sustained release of growth factors.

9. The injection method according to claim 7, characterized in that, Composite gel injection is used: inject at a flow rate of 0.08-0.12 mL / s, and maintain the needle tip temperature at 6-8℃ during the injection process; During injection, an alternating magnetic field of 3V and 50Hz is applied, resulting in a magnetic particle dispersion of over 90%, and the dispersion kinetics conform to: Where D0 is the maximum dispersion and B is the magnetic field strength; After injection, a 0.5T directional static magnetic field was applied (for 6 hours), and the growth factor migration distance (d) met the following requirements: Where X is the magnetic susceptibility of the magnetic particles (0.05-0.1 emu / g·Oe), ▽B is the magnetic field gradient, η is the gel viscosity, and r is the radius of the magnetic particles.

10. The injection method according to claim 7, characterized in that, The static magnetic field is generated by a focusing magnetic ring.

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