The biological and medicinal implant material of controllable degradation rate and application thereof
Technical field
The present invention relates to the bio-medical metal implant material, specifically the biological and medicinal implant material of controllable degradation rate and application thereof.
Background technology
The degradation material of medically using mostly is macromolecular material at present, and there are the following problems for degradable high polymer material: 1. intensity is low, and hardness and rigidity are low; 2. degraded poor controllability, degradation time and intensity, rigidity are disproportionate, thereby lose intensity in the degradation process easily too early device are lost efficacy in advance; 3. processing stability is poor, and the processing of degraded macromolecular material needs special processing environment and equipment; Therefore develop novel controlled degradation degraded embedded material, all significant for the development of demand that satisfies clinical practice, patient and biomaterial.
The corrosion resisting property of magnesium and magnesium alloy is relatively poor, and the normal potential of pure magnesium is-2.37V especially to contain Cl
-All the more so in the ionic Human Physiology environment, pure magnesium commonly used and magnesium alloy are in simulated body fluid, the corrosion degradation rate can reach 0.1-5mm/year, the alloy element of the corrosion rate of pure magnesium and magnesium alloy and material itself, microstructure (grain size, precipitates etc.), factors such as impurity content, machining state and apparent condition are closely related, for example reduce impurity content, reduce crystallite dimension and all can effectively slow down the corrosion rate of pure magnesium and magnesium alloy, if carry out surface modification treatment again, its corrosion degradation rate can be controlled in 0.01-5mm/year.Therefore it is feasible utilizing the characteristics development new bio medical degradable absorption metal implant material of corrosion stability of magnesium alloy difference.
But pure magnesium commonly used and magnesium alloy are in simulated body fluid, there is the serious pitting phenomenon, although can be by alloy optimization, reduce crystallite dimension, reduce measures such as impurity content and slow down local corrosion situations such as spot corrosion, but for implant devices, the generation of spot corrosion seriously reduces the mechanical property of device to a great extent in the corrosion degradation process, make the inefficacy in advance of device, may cause serious consequence the patient.Therefore must stop pure magnesium of degradable and magnesium alloy in degradation process (particularly during one's term of military service) as far as possible the severe pitting phenomenon takes place at implant devices; in the pure magnesium and magnesium alloy protection process of routine; usually adopt surface modification (as anodic oxidation, the injection of nitrogen ion surface, laser aid in treatment etc.) to come Mg alloy surface is protected, make magnesium alloy avoid corroding or slowing down corrosion.In development pure magnesium of degradable and magnesium alloy process, the corrosion rate that also can adopt the method for surface modification to slow down material, but in being rich in the body fluid environment of chloride ion, pure magnesium and magnesium alloy still exist point corrosion, the potential threat that still exists device to lose efficacy in advance inevitably.Therefore avoid local corrosion, adopt more superior degraded control method extremely important for the development of pure magnesium of controlled degradation and magnesium alloy.
China's magnesium resource is abundant, and advantage that the magnesium alloy metallic biomaterial shows and potentiality must cause more and more people's concern.Development biomedical degradation-controllable magnesium alloy embedded material is to the wide application in the embedded material field of pure magnesium and magnesium alloy, will produce huge progradation to the development of China's biomaterial industry and magnesium goods industry.
Summary of the invention
The purpose of this invention is to provide a kind of biological and medicinal implant material and application thereof of controllable degradation rate, make it in the corrosion degradation process, degradation rate and implant devices active time are complementary, and guarantee implant devices intensity and rigidity during one's term of military service simultaneously.
For achieving the above object, the technical solution used in the present invention is:
The biological and medicinal implant material of controllable degradation rate is a matrix with pure magnesium or magnesium alloy materials, its surface-coated one deck degradable high polymer material, and the THICKNESS CONTROL of coating is at 0.01-5mm; Make the biodegradation proceed step by step of pure magnesium and magnesium alloy, can guarantee the mechanical property of material in the degradation process, thereby reach the purpose of controlled degradation.
Described pure magnesium is medical pure magnesium or high-purity magnesium; Magnesium alloy is, the alloy system that magnalium series alloy, magnesium manganese series alloy, magnesium zinc series alloy, magnesium zirconium series alloy, magnesium rare earth metal alloy, magnesium lithium series alloy, magnesium calcium series alloy or magnesium silver series alloy etc. are different a kind of or the ternary system and the polynary system magnesium alloy that are formed by these system combinations.
The content of alloying element should satisfy the requirement of bio-medical basically in the above-mentioned magnesium alloy, makes its degradation amount in degradation process should be in not causing the dosage range of tissue toxicity reaction; Related pure magnesium and magnesium alloy mainly comprise: pure magnesium (weight content is more than 99%), magnalium series (mainly comprises Mg-Al-Zn except that binary system, Mg-Al-Mn, Mg-Al-Si, four ternary systems of Mg-Al-RE and other multicomponent systems, alloy representative such as AZ31, AZ61, AM60, AM50, AE21, AS21 etc., wherein the aluminum weight content requires less than 10%, Zn, Mn, Si and/or RE weight content content are less than 5%), magnesium manganese series (mainly is binary Mg-0.1~2.5%Mn and adds a small amount of rare earth, calcium, ternary system that zinc etc. are elementary composition or polynary system, represent alloy such as domestic trade mark MB1 and MB8), magnesium zinc series (mainly comprises Mg-Zn-Zr and Mg-Zn-Cu series except that binary system, alloy representative such as ZK21, ZK60, ZC62 etc.), magnesium zirconium series (mainly is binary Mg-0.1~1%Zr and adds a small amount of rare earth, ternary system that zinc etc. are elementary composition or polynary system, represent alloy such as K1A etc.), the magnesium rare earth metal (mainly is binary Mg-0.1~5%RE and interpolation small amount of aluminum, zirconium, calcium, ternary system that zinc etc. are elementary composition or polynary system,), magnesium lithium series (mainly is binary Mg-1~15%Li and interpolation small amount of aluminum, rare earth, ternary system that zinc and silicon etc. are elementary composition or polynary system, represent alloy such as LA91, LAZ933 etc.), magnesium calcium series (mainly is binary Mg-0.1~3%Ca and adds a small amount of rare earth, zirconium, ternary system that zinc etc. are elementary composition or polynary system), magnesium silver series (mainly is binary Mg-0.1~12%Ag and adds a small amount of rare earth, zirconium, ternary system that zinc etc. are elementary composition or polynary system are represented alloy such as QE22 etc.) etc. different alloy system a kind of or the ternary system and the polynary system magnesium alloy that form by these system combinations.For pure magnesium and magnesium alloy, its corrosion degradation rate in simulated body fluid or body fluid can be by changing the composition of material itself, and conditions such as crystallite dimension and condition of heat treatment are controlled at 0.01-5mm/year.
Degradable high polymer material involved in the present invention can be selected the biodegradation material that is usually used at present clinically for use, mainly comprise collagen protein, gelatin, natural degradable macromolecular material and polylactide (polylactic acid such as chitin, PLA), poly-Acetic acid, hydroxy-, bimol. cyclic ester (polyglycolic acid, PGA), polybutylcyanoacrylate (PACA), polycaprolactone (PCL), poly-anhydride (comprises the aliphatic poly anhydride, fragrance adoption anhydride, heterocycle adoption anhydride, the poly-anhydride of polyamides anhydride and crosslinkable etc.), copolymer between synthesized degradable macromolecular materials such as poe and/or poly-phosphorus are fine and the above-mentioned polymer etc.With the commercializations such as spicule, medicine sustained release carrier and support that their are made, its degradation rate in body fluid and simulated body fluid can be controlled at easily from a week by several years.Surface coating technology involved in the present invention can adopt: dip-coating, thermal spraying, sol-gal process etc., coating layer thickness can be controlled in 0.01mm between the 5mm according to the device needs, must eliminate rust before applying, oil removing, also can adopt pretreatment such as phosphatization, coupling agent.
Controlled degradation bio-medical metal implant material of the present invention can be used for the temporary transient or short-term medical bio implant devices of preparation, as degradable angiocarpy bracket and peripheral bracket, and internal fixation blade plate and nail and tissue engineering rack material etc.
Bio-medical controlled etching provided by the present invention degrade pure magnesium and magnesium alloy materials come the speed of the early stage degraded of control material by the degradable macromolecule coating, guarantee mechanical property in the degradation process by magnesium alloy substrate.
The present invention has following advantage:
1. specific strength and specific rigidity height.Relative degradable high polymer material, pure magnesium of biomedical degradation-controllable and magnesium alloy materials through surface-coated is handled still have higher specific strength and specific rigidity; Not matching of degradation time and intensity takes place in degradable high polymer material easily in degradation process, premature loss intensity, and the pure magnesium of degradable and its degradation process of magnesium alloy after the present invention's processing divide two stages to carry out: surperficial before this degradable macromolecule coating is degraded gradually, be magnesium metal matrix material corrosion degraded then, come the speed of the early stage degraded of control material in the material degradation process by the degradable macromolecule coating, mechanical property by in the magnesium alloy substrate assurance degradation process makes the interim under arms effective maintenance good mechanical performance of whole implant devices.Pure magnesium and magnesium alloy materials have the elastic modelling quantity approaching with people's bone simultaneously, if the devices relevant with skeleton such as making bone fixture can be avoided the stress barrier effectively, are very beneficial for symphysis.
2. degradation rate is easily controlled.The advantage of the abundant combination of the present invention and the performance pure magnesium of degradable and magnesium alloy and degradable macromolecule, can solve the fast problem of intensity decreases in the low and degradation process of degradable high polymer material intensity, utilize the easy control of degradable high polymer material degradation rate simultaneously, according to the phase design surface degradable macromolecule coating parameter of being on active service, control early stage degradation process, make early stage pure magnesium of degraded and magnesium alloy materials that the corrosion degraded not take place, avoid local corrosion phenomenons such as spot corrosion, make integral material keep excellent mechanical property; The magnesium matrix material is slowly degraded in the degraded later stage (being that implant is near designing military service during the phase), even local corrosions such as generation spot corrosion are also little to the function effect of implantation piece.By optimizing the degradation cycle of face coat and magnesium alloy substrate, can obtain to satisfy the pure magnesium of biological medical degradable and the magnesium alloy materials of different clinical demands.
3. safe, practical property is good.Pure magnesium and magnesium alloy have many advantages as embedded material: 1. magnesium resource is abundant, low, the wide material sources of relative cost; 2. the density of magnesium and magnesium alloy is 1.74g/cm
3About, with the Compact bone density (1.75g/cm of people's bone
3) very approaching; 3. magnesium and magnesium alloy have high specific strength and specific stiffness; 4. the Young's modulus of elasticity of magnesium and magnesium alloy is about 45GP, about the elastic modelling quantity 20GPa near people's bone, can avoid stress-shielding effect as implant; 5. magnesium is the macroelement that is only second to calcium, sodium and potassium in the human body, and everyone the daily requirement amount of being grown up is greater than 350mg, and it participates in a series of metabolic processes in the body.Finally be corroded under the physiological environment in vivo degraded and absorbed or metabolism of degradable magnesium and magnesium alloy by body, its catabolite mainly is the magnesium ion of needed by human body, magnesium is the needed by human body macroelement, contained other alloying element contents are all within the bio-medical scope, selected degradable high polymer material also is commonly used clinically at present, therefore it is safe that pure magnesium after adopting the present invention to handle and magnesium alloy prepare the medical embedded device of controlled degradation, has very big advantage and application prospect.
The specific embodiment
Embodiment 1
Adopt pure magnesium to be made into the coronary artery bracket sample (after polishing, the silk footpath is at 70-80 μ m), respectively at acetone, ultrasonic cleaning is 5 minutes in the ethanol, at the vacuum drying oven inner drying, putting into polylactic acid (PLA) solution (0.1g/mL) then soaked 10 minutes, with motor pure magnesium sample is at the uniform velocity lifted out solution, 1000 rev/mins of following centrifugal treating 1 minute, then support is put into the vacuum drying oven inner drying, can repeat the dip-coating number of times according to thickness requirement, the present embodiment coating layer thickness will be immersed in after handling by corroding degraded fully in the simulation plasma solutions of table 1 preparation after about 9 months at 11 μ m.
Because the corrosion rate of pure magnesium material can be adjusted by factors such as impurity content and crystallite dimension and heat treatments, the degradation rate of polylactic acid also can be controlled according to the molecular weight of polylactic acid and the thickness of coating, so can be optimized from pure magnesium and polylactic acid two aspects according to the degradation rate of the pure magnesium coronary artery bracket of medical controlled degradation that passes through above prepared.
Table 1: artificial blood plasma is formed
Chemical compound |
NaCl |
CaCl
2 |
KCl |
MgSO4 |
NaHCO
3 |
Na
2HPO
4 |
NaH
2PO
4 |
Concentration, mg/L |
6800 |
200 |
400 |
100 |
2200 |
126 |
26 |
Embodiment 2
With the AZ31B magnesium alloy through the polishing after, ultrasonic cleaning 5 minutes in acetone, ethanol respectively, at the vacuum drying oven inner drying, polyglycolic acid (PGA) solution (0.2g/mL) of putting into different molecular weight then soaked 20 minutes, with motor AZ31B magnesium alloy sample is at the uniform velocity lifted out solution,, then support is put into the vacuum drying oven inner drying 1000 rev/mins of following centrifugal treating 1 minute, can repeat the dip-coating number of times according to thickness requirement, present embodiment floating coat thickness is 23 μ m.
Because the corrosion rate of AZ31B magnesium alloy materials can be adjusted by factors such as impurity content and crystallite dimension and heat treatments, the degradation rate of polyglycolic acid also can be controlled according to the thickness of molecular weight and coating, so can be optimized from alloy substrate and surperficial polyglycolic acid coating two aspects according to the degradation rate of the medical controlled degradation magnesium alloy materials that passes through above prepared.
Embodiment 3
With high-purity magnesium (99.98%) through the polishing after, ultrasonic cleaning 5 minutes in acetone, ethanol respectively, at the vacuum drying oven inner drying, copolymer (PLGA) solution (0.05g/mL) of putting into polylactic acid and polyglycolic acid then soaked 40 minutes, with motor pure magnesium sample is at the uniform velocity lifted out solution,, then support is put into the vacuum drying oven inner drying 1000 rev/mins of 30 seconds of following centrifugal treating, can repeat the dip-coating number of times according to thickness requirement, the present embodiment coating layer thickness is 8 μ m.。
Because the corrosion rate of pure magnesium material can be adjusted by factors such as impurity content and crystallite dimension and heat treatments, the degradation rate of the copolymer of polylactic acid and polyglycolic acid also can be controlled according to the thickness of the two proportioning and coating, so can be optimized from coating two aspects of alloy substrate and surperficial polylactic acid and polyglycolic acid according to the degradation rate of the medical controlled degradation magnesium alloy materials that passes through above prepared.
Embodiment 4
With the AM60 magnesium alloy through the polishing after, ultrasonic cleaning 5 minutes in acetone, ethanol respectively, at the vacuum drying oven inner drying, putting into the insulation of polylactic acid molten state liquid then soaked 10 minutes, suitable mould is put in the material taking-up to be cooled off, the demoulding is after finishing is used, and the present embodiment coating layer thickness is 1mm.
Because the corrosion rate of AM60 magnesium alloy materials can be adjusted by factors such as impurity content and crystallite dimension and heat treatments, the degradation rate of polylactic acid also can be controlled according to the thickness of molecular weight and coating, so can be optimized from alloy substrate and surperficial polylactic acid coating two aspects according to the degradation rate of the medical controlled degradation magnesium alloy materials that passes through above prepared.
Embodiment 5
With the ZK60 magnesium alloy through the polishing after, ultrasonic cleaning 5 minutes in acetone, ethanol respectively, at the vacuum drying oven inner drying, polycaprolactone (PCL) solution (0.1g/mL) of putting into different molecular weight then soaked 30 minutes, with motor ZK60 magnesium alloy sample is at the uniform velocity lifted out solution,, then support is put into the vacuum drying oven inner drying 1000 rev/mins of following centrifugal treating 1 minute, can repeat the dip-coating number of times according to thickness requirement, the present embodiment coating layer thickness is 18 μ m.
Because the corrosion rate of ZK60 magnesium alloy materials can be adjusted by factors such as impurity content and crystallite dimension and heat treatments, the degradation rate of polycaprolactone also can be controlled according to the thickness of molecular weight and coating, so can be optimized from alloy substrate and surperficial polycaprolactone coating two aspects according to the degradation rate of the medical controlled degradation magnesium alloy materials that passes through above prepared.
Embodiment 6
Difference from Example 5 is:
Magnesium alloy is MB1, and degradable high polymer material is collagen protein (0.5g/mL), and the insulation soak time is 10 minutes, and coating layer thickness is 4mm.
Embodiment 7
Difference from Example 5 is:
Magnesium alloy is K1A, and degradable high polymer material is isopyknic gelatin and chitin (0.1g/mL), and the insulation soak time is 15 minutes, and coating layer thickness is 0.9mm.
Embodiment 8
Difference from Example 5 is:
Magnesium alloy is LA91, and degradable high polymer material is poe (0.05g/mL), and the insulation soak time is 40 minutes, and coating layer thickness is 0.4mm.
Embodiment 9
Difference from Example 5 is:
Magnesium alloy is QE22, and degradable high polymer material is that polybutylcyanoacrylate (0.2g/mL), insulation soak time are 25 minutes, and coating layer thickness is 2mm.