CN107501447A

CN107501447A - Ultra-low abrasion polyethylene and its application in artificial joint prosthesis

Info

Publication number: CN107501447A
Application number: CN201710822452.1A
Authority: CN
Inventors: 翁习生; 边焱焱; 彭慧明; 邹运
Original assignee: Peking Union Medical College Hospital Chinese Academy of Medical Sciences
Current assignee: Peking Union Medical College Hospital Chinese Academy of Medical Sciences
Priority date: 2017-09-13
Filing date: 2017-09-13
Publication date: 2017-12-22

Abstract

The invention discloses a kind of application of ultra-low abrasion polyethylene in artificial joint prosthesis.The invention also discloses a kind of artificial joint component, the artificial joint component is to be formed by ultra-low abrasion polythene material by certain chemically or physically method processing.Ultra-low abrasion polyethylene good mechanical property provided by the invention, good biocompatibility, security is good, manufactured artificial joint prosthesis good mechanical property, easily fabricated machine-shaping, and chemicals stability is high, and abrasion resistance properties are good.

Description

Ultra-low abrasion polyethylene and its application in artificial joint prosthesis

Technical field

The present invention relates to technical field of biomedical materials, and in particular to ultra-low abrasion polyethylene and its in joint prosthesis Application in prosthese.

Background technology

As social senilization is in progress, hip, middle-aged and old quantity cumulative year after year of kneecap joint degeneration disease are suffered from, evening Serious arthralgia, deformity and dyskinesia can occur in phase.Replacement of total hip (total hip Arthroplasty, THA) and total knee arthroplasty (total knee arthroplasty, TKA) be treatment middle and advanced stage it is tight The Main Means of weight osteoarthropathy, can effective pain of alleviation, rebuild function of joint and mobility, thus obtained widely facing Bed application, amount for surgical rise year by year.2010, U.S.'s whole year TKA amount for surgical reached 600000, and THA amount for surgical exceedes 300000, it is contemplated that to the year two thousand thirty, the U.S. will have 3,480,000 TKA and 572000 THA operations, and increase respectively than 2010 every year Long 673% and 174%.Compared with western countries, suffer from the patient numbers up to 65,000,000 of osteoarthropathy in China, 40 years old crowd's Illness rate is 10%~17%, over-65s 60%, and crowd is 80% within more than 75 years old, and disability rate is up to 53%, that is, has half Patient above may need pedestrian's work joint replacement surgery, and it is in rejuvenation trend to fall ill, and material is implanted into joint prosthesis Combination property and service life propose higher requirement.

Artificial joint material includes ceramics, metal, polyethylene etc., and the hardness of wherein polythene material is minimum, is easiest to send out Raw regression, abrasion, are links most weak in artificial joint prosthesis.Numerous studies show, caused by artificial joint prosthesis abrasion Abrasive dust especially polyethylene (polyethylene, PE) abrasive dust, at most (70%~90%), distribution is most wide, can cause for quantity Biologically near Periprosthetic bone interface, secondary bone dissolve and ultimately result in prosthese aseptic loosening, turn into limitation people The main reason of work articular prosthesis long term service life.Fatigue strength, prosthese fixed form and art in materials for joint prosthesis After the control of postoperative infection rate makes progress, the abrasion resistance properties of prosthetic material especially polyethylene how are improved, reduce friction system Number and wear rate turn into the focus of artificial joint material research.

Polythene material molecular weight applied to joint prosthesis is general all in 2,000,000 more than g/mol, thus is referred to as superelevation Molecular weight polyethylene (ultra-high-molecular weight polyethylene, UHMWPE).UHMWPE is high compared with other Molecularly Imprinted Polymer has more excellent biocompatibility, mechanical performance and abrasion resistance properties, is always artificial for a long time The preferred material of joint load cell tibial plateau pad and acetabular bone liner.Before nineteen ninety-five, UHMWPE enters in aerobic environment 25~40kGy of row γ radiation sterilization, causes it to remain substantial amounts of free radical in vivo, and free-radical oxidation can cause its oxidation drop Solution, fragility increase, so as to reduce its abrasion resistance properties.Therefore from after the nineties in last century, the sterilizing of UHMWPE finished products is changed to Oxirane (Ethylene Oxide, EtO) or plasma gas, or the γ spokes in weary oxygen environment (such as vacuum or nitrogen) Penetrate.In recent years, material scholars by way of the crosslinking degree and filling vitamin E that improve UHMWPE as far as possible to it changing It is good, enhance its wear resistance and inoxidizability.

Physics and chemistry, mechanical performance and the Bio-tribological Properties of joint prosthesis polythene material use the longevity for articular prosthesis Life plays an important role.As a kind of bio-medical material for needing to be chronically implanted human body, following basic demand should be met：

1) good biocompatibility

The premise that biomaterial obtains clinical practice is that have good biocompatibility and security.Biocompatibility is Whether the compatibility after biomaterial for medical purpose implantation human body with host, i.e., can cause to poison, this is mainly by material to tissue Expect that host's foreign body reaction degree determines caused by self character.A series of interactions occur in polythene material-organizational interface Afterwards, it can finally be received by tissue, foreign rejection, the normal physiological function of human body be had no adverse effects, to people Body is non-toxic, without sensitization, nonirritant, non-carcinogenesis and genetoxic, to tissue, blood and the system such as immune not Produce adverse reaction.

2) excellent bio-tribology performance

Polyethylene abrasive dust can induce the biologically of Periprosthetic fiber limitans, be cause bone dissolve it is main because Element, therefore it is required that it there should be good abrasion resistance properties, the formation of abrasive dust is reduced, extend the prosthese Clinical practice longevity as far as possible Life.

3) good corrosion-resistant, impact resistance, fatigue performance.

4) good electrical insulating property, chemicals stability.

5) easily fabricated machine-shaping, cost are cheap.

The content of the invention

The purpose of the present invention is to be directed to above-mentioned technical problem, invents a kind of new joint prosthesis polythene material, and study Its biocompatibility and security in joint prosthesis used in surgical operation etc., it is the application of artificial joint prosthesis clinically Theoretical foundation and technical support are provided.

Based on this, present invention firstly provides a kind of application of ultra-low abrasion polyethylene in artificial joint prosthesis.

Preferably, the ultra-low abrasion polyethylene (ultra-low-wear polyethylene, ULWPE), it is using spy Different transition metal single active center coordination polymerization catalysts, a kind of weight average molecular weight prepared under gentle polymerization process condition Between 40~700,000, narrow ditribution Alathon of the molecular weight distribution between 2.0~3.5 (not including 2.0 end values).According to first Pacing is determined, and ULWPE molecular topology is a kind of regular linear molecule of height that there is no side chain substitution, average every 100000 carbon atoms only have 2 side chains.For ULWPE because molecular weight is relatively low, weight average molecular weight is only 10 to 20 points of UHMWPE One of, therefore it is easily achieved melting extrusion, direct injection molding or 3D printing processing.Than UHMWPE high temperature sintering and after Continuous machine cut processing, ULWPE has machining accuracy high, outstanding advantages of loss without material.With gamma under equal conditions The UHMWPE of ray radiation treatment is compared, the abrasion resistance properties that ULWPE material products are shown will good several times to ten several times, therefore It may be said that its abrasion resistance brilliance is preeminent.

Wherein, the preparation method of the ultra-low abrasion polyethylene is included in carried metallocene catalyst and the second alkyl In the presence of aikyiaiurnirsoxan beta, ethene is subjected to slurry polymerization, wherein, the carried metallocene catalyst includes carrier and load Metallocene compound, alkyl aluminum and the first alkylaluminoxane on the carrier, the metallocene compound are rac-R¹ ₂-Si (2-R²-4-Ar-Ind)₂MX₂, R¹And R²Respectively C₁-C₅Alkyl in one kind, Ar is aryl, and Ind is indenyl, and M is titanium, zirconium With one kind in hafnium, X is one kind in halogen.

Further, the invention provides a kind of artificial joint component, the artificial joint component gathered by ultra-low abrasion Vinyl material forms by certain processing, it is preferred that the artificial joint prosthesis includes any available for operation auxiliary The artificial organs for the treatment of, as artificial knee joint, fixture, joint simulator, artificial knee joint tibial plateau pad and artificial close Save acetabular bone liner etc..

The hardness of the joint prosthesis polyethylene part is lower than prosthetic component prepared by metal or ceramics, and contact with each other friction When be easier to wear, its Wear Mechanism mainly has following three kinds.

Adhesive wear (adhesive wear)

Generally, it is considered that polyethylene abrasive dust is mainly derived from adhesive wear.So-called adhesive wear generally occurs in two kinds of structures Into in the relative motion of the different material of the hardness in joint (such as metal-polyethylene).In the motion of periodic single axial, The less polyethylene surface of hardness is extruded and stretched repeatedly to flour milling by smooth, is caused material micro-bulge to be broken and is produced drawing Long tiny fibrous abrasive dust, material surface form hollow or depression.Adhesive wear degree and polyethylene surface molecules align Directionality is closely related.Molecules align is in more one-way, and material ductility is stronger, and adhesive wear is more serious.

Abrasive wear (abrasive wear)

Abrasive wear is due to existing hard in coarse hard surface (such as coarse metal joint face) or contact interface Matter third party particle (such as bone, metal, ceramics or bone cement chip etc.) is led caused by polyethylene elements surface repeatedly abrasion cutting Its surface scratching wound, micro-cutting and micro- ditch dug with a plow etc. is caused to change.It is this to wear the mainly surface nature by hard material, polyethylene Mechanical performance of itself etc. influences.

Fatigue wear (fatigue wear)

In process of friction and wear is circulated, because the defects of material self structure such as aoxidizes regression, polyethylene is periodically Under alternate load effect, the interphase interaction of the part micro-bulge on its surface, larger stress is generated in contact area And deformation, crackle and layering are formed on the top layer of polyethylene and subsurface stratum, causes material wear-out failure.

Joint prosthesis polyethylene wear and " abrasive dust disease "

Artificial joint prosthesis moves along with human body, mutual fretting wear can occur between secondary to mill, unavoidably Abrasive dust, including polyethylene abrasive dust, metal filings, ceramic abrasive dust and bone cement abrasive dust etc. can be formed.Abrasive dust can induce prosthese week The biologically of fiber limitans is enclosed, stimulating expression of macrophage secretion bone resorption sex factor, causes the dissolving of Periprosthetic bone and aseptic Loosen, be referred to as " abrasive dust disease ".Inflammatory reaction degree is related to abrasive dust type and quantity.Polyethylene abrasive dust causes bone to dissolve Main factor, its quantity is most, and distribution is most wide, constitutes about the 70%~90% of all abrasive dusts, 92% polyethylene abrasive dust is straight Footpath is less than 1 μm.

The phagocytosis of macrophage and the activation of osteoclast play heavy to closing during polyethylene wear debris-induced osteolysis The effect wanted.Macrophage in abrasive dust activation peri-prosthetic tissues, macrophage release osteolytic cytokine activation are osteoclastic thin Born of the same parents, osteoclast cause bone information aggravation and impaired bone formation by lyase etc.., can be huge when polyethylene abrasive dust is less than 10 μm Phagocyte swallows, and larger polyethylene abrasive dust is then wrapped by macrophage.Abrasive dust stimulating expression of macrophage discharges inflammatory mediator such as tumour Necrosis factor-alpha (TNF-α), il-1 (IL-1), prostaglandin E2 (PGE2) and metalloproteinases (such as clostridiopetidase A), Wherein TNF-α effect is mostly important.TNF-α can stimulate Gegenbaur's cell to produce granulocyte-macrophage colony-stimulating factor (GM-CSF) With interleukin-6 (IL-6), both media all produce chemotaxis to other macrophages, osteoclast and inflammatory cell, Cause inflammation.In addition, TNF-α is a kind of osteolytic cell factor, the bone information of osteoclast can be stimulated, this bone information is broken The bon e formation of prosthese and firmware is broken, causes clinically seen aseptic loosening.Abrasive dust can be produced with stimulating expression of macrophage Discharge the RANKL factors, the factor can be incorporated on the RANKL acceptors of osteoclastic precursor cell surface expression, and promote it is osteoclastic before Somatic differentiation is ripe, produces the osteoclastic precursor with bone resorption activity, the generation for causing bone to dissolve.

In order to increase crosslinking rate, ultra-low abrasion polyethylene used in the present invention is to increase crosslinking rate using radiation treatment protocols, The space structure of ULWPE molecules is changed under specially 1~200kGY x ray irradiation xs, and caused free radical is bound to each other to form Lateral covalent bond, make ULWPE molecules aligns more multidirectional, reduce the ductility of material, so as to considerably reduce adhesion mill The generation of damage and the formation of abrasive dust.

Preferably, ultra-low abrasion polyethylene used in the present invention is also eliminated as much as material using modes such as composite antioxidants Middle free radical, strengthen wearability, reduce abrasive dust.Such as add a certain amount of 0.06%~0.08% natural vitamin E.

Further, the artificial joint prosthesis is by the injection molding of ultra-low abrasion polyethylene or 3D printing after processing Shaping.

Beneficial effect of the present invention：

Ultra-low abrasion polyethylene good mechanical property provided by the invention, good biocompatibility, security is good, manufactured artificial Articular prosthesis good mechanical property, easily fabricated machine-shaping, chemicals stability is high, and abrasion resistance properties are good.

Brief description of the drawings

After Fig. 1 light Microscopic observation is with ULWPE leaching liquors, UHMWPE leaching liquors and 0.64% phenol solution culture 12h and 24h The metamorphosis (× 400) of L929 cells；

Fig. 1-A test groups:ULWPE leaching liquor culture cells 12h；

Fig. 1-B test groups:ULWPE leaching liquor culture cells 24h；

Fig. 1-C negative control groups：UHMWPE leaching liquor culture cells 12h；

Fig. 1-D negative control groups：UHMWPE leaching liquor culture cells 24h；

Fig. 1-E positive controls：Phenol solution culture cell 12h；

Fig. 1-F positive controls：Phenol solution culture cell 24h.

(note：Test group cellular morphology (Fig. 1-A, 1-B) is substantially the same, cellular morphology with negative control group (Fig. 1-C, 1-D) Homogeneous, in similar round or spindle shape, adherent growth is good, acellular dissolving；Positive controls (Fig. 1-E, 1-F) L929 cells are complete It is complete to destroy, obvious cytotoxicity is presented.)

The om observation result (HE dyeing × 200) of Fig. 2 rat muscles implantation local reaction experiment；

Fig. 2-A：1 week after ULWPE implantation；

Fig. 2-B：1 week after UHMWPE implantation；

Fig. 2-C：4 weeks after ULWPE implantation；

Fig. 2-D：4 weeks after UHMWPE implantation；

Fig. 2-E：12 weeks after ULWPE implantation；

Fig. 2-F：12 weeks after UHMWPE implantation；

Fig. 2-G:26 weeks after ULWPE implantation；

Fig. 2-H：26 weeks after UHMWPE implantation.

(note：1 week after implantation (Fig. 2-A, 2-B), ULWPE and UHMWPE surrounding materials intramuscular has a large amount of inflammatory cells Infiltration, musculature are formed without deformation necrosis, no fibrous capsule；4 weeks after implantation (Fig. 2-C, 2-D), inflammatory cell is reduced, into fibre Cell and angioblast propagation are tieed up, forms loose, became uneven fibrous capsule；(Fig. 2-E, 2-F), inflammatory 12 weeks after implantation Cell is most to disappear, and has complete and fine and close fibrous connective tissue coating to be formed；26 weeks after implantation (Fig. 2-G, 2-H), have no scorching Property reaction, chronic granulo hyperblastosis.Same time point compares two kinds of storeroom no significant differences.) Fig. 3 is Chronic Liver renal toxicity The om observation result (HE dyeing × 200) of experiment；

Fig. 3-A：ULWPE be implanted into 12 weeks after rat liver；

Fig. 3-B：ULWPE be implanted into 12 weeks after rat kidney.

(note：Liver cell becomes without oedema and fat, and portal area is without bile duct proliferation；Glomerulus has no mesangial matrix *, nothing in tubule Cast, interstitial is without inflammatory reaction.Pathological examination shows ULWPE without Chronic Liver renal toxicity.)

Embodiment

Following examples are used to illustrate the present invention, but are not limited to the scope of the present invention.Unless otherwise specified, embodiment In the conventional meanses that are well known to those skilled in the art of used technological means.

The preparation of the ultra-low abrasion polyethylene of embodiment 1

(1) preparation of catalyst：

1g silica gel and 10mmol triethyl aluminums are added in toluene, is reacted 5 hours at 100 DEG C, is removed supernatant liquor and obtain To after slurry, slurry is washed 5 times with toluene.Then, 12g10 weight % methylaluminoxane toluene solution is added, with Above-mentioned slurry reacts 4 hours at 60 DEG C, after removing supernatant liquor, will obtain slurry and is washed 5 times with toluene.Add 40mg rac-(CH₃)₂Si(2-CH3-4-Ph-Ind)₂ZrCl₂, reacted 4 hours at 50 DEG C with the slurry, will after removing supernatant liquor Obtain slurry to be washed 5 times with toluene, finally dried 1 hour in 50 DEG C of vacuum drying oven, obtain loaded metallocene catalysis Agent.

After testing, in the carried metallocene catalyst, the content of metal zirconium is 0.5 weight %, and the mol ratio of aluminium/zirconium is 101：1.

(2) ethylene homo

Autoclave is purged with nitrogen, then nitrogen is replaced with ethene, repeats three times.Then, according to support type Metallocene catalyst 20mg, 10g base aikyiaiurnirsoxan beta (that is, MAO, being 10 weight % MAO toluene solution), n-hexane solvent 500ml is added, and is stirred 10 minutes.Then ethene is passed through with 0.5MPa pressure, carried out under conditions of 85 DEG C, 5atm, 60min Polymerization.After reaction terminates, acidic ethanol (containing 10 volume % hydrochloric acid) is added into reactor with terminating reaction, and carried out Filter, obtains pulverulent solids, and with 100mL ethanol and 200mL water washings three times after, be in temperature by obtained pulverulent solids Dried in 50 DEG C of vacuum drying oven to constant weight, so as to obtain ultra-low abrasion polyethylene ULWPE.

(3) crosslinking Treatment

The space structure of ULWPE molecules obtained by step (2) changes under 1~200kGY x ray irradiation xs, it is caused from Lateral covalent bond is bound to each other to form by base, makes ULWPE molecules aligns more multidirectional, reduces the ductility of material, so as to pole The earth reduces the generation of adhesive wear and the formation of abrasive dust.

(4) anti-oxidant treatment

A certain amount of 0.06%~0.08% natural anti-oxidation is added on the basis of ultra-low abrasion polyethylene obtained by step (3) Agent vitamin E, free radical in material is eliminated as much as, strengthens wearability, reduce abrasive dust.

Obtain ultra-low abrasion polythene material.

The ultra-low abrasion polyethylene biocompatibility test of embodiment 2 is studied

First, material

(1) experimental raw

1. raw material：Ultra-low abrasion polythene material prepared by embodiment 1.

2. negative control is examined from German import implantation class super-high molecular weight polyethylene powder by national quality supervision and inspection Epidemic disease general bureau provides.

(2) experimental animal and cell

1. 8 week old SPF level SD rats 20, body weight (194.8 ± 8.32) g, male and female half and half.

2.SPF levels kunming mice 30, body weight (22.4 ± 1.5) g, male and female half and half.

3. common cleaning grade new zealand white rabbit 1, body weight 2.5kg, male.

Above animal detects by Beijing experimental animal quality inspection station, is provided by BJ Union Hospital's animal experimental center (credit number：SYXK capital 2010-0028) and carry out conventinal breeding.

The strain of 4.L929 l cells is purchased from Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences's cell centre.

(3) key instrument

(4) main agents

2nd, method

(1) external acute cytotoxicity experiment (CCK-8 colorimetric methods)

According to " GB/T 16886.5-2003/ISO 10993-5:The part of 1999 BiologicalEvaluationofMedicalDevice the 5th：In vitro The standard of cell toxicity test " carries out following experimental study.

1. the preparation of material leaching liquor

According to " GB/T 16886.12-2005/ISO 10993-12:2002 BiologicalEvaluationofMedicalDevice standards the 12nd Point：It is prepared by the standard of sample preparation and reference sample ".

1) electronic balance weighs ULWPE powder 5g, adds and 24h degreasings are soaked in absolute ethyl alcohol, and distilled water dries after washing 3 times It is dry, then after 125 DEG C of autoclave sterilization 30min it is standby.

2) 500mlDMEM high glucose mediums are taken, add hyclone, 50U/ml penicillin and the 50U/ of volume fraction 10% Ml streptomysins are standby.

3) sample is put into sterile test tube, in quality of materials with extraction medium volume than 1g/5ml ratio and above-mentioned culture Liquid (extraction medium) 25ml mixing, sealing, are statically placed in 37 DEG C of chemical inertness CO₂72h is extracted in cell culture incubator.

4) filtrate is moved into after 0.22 μm of millipore filter filtering of Millipore standby in another sterile test tube.

5) negative control group prepares leaching liquor from UHMWPE powders, and preparation method is same as above.

6) positive controls select 0.64% phenol, and 0.16g phenol is added into 25ml containing 10% hyclone, 50U/ml It is formulated in the DMEM nutrient solutions of penicillin and 50U/ml streptomysins (extraction medium).

2. prepared by cell culture, passage and cell suspension

1) L929 l cell strains are selected, are added in above-mentioned culture medium, in 37 DEG C, 5%CO₂, 100% humidity Cultivated in cell culture incubator, recover, pass on, changed liquid once within 48 hours, cultivate to exponential phase.

2) observe cellular morphology under inverted microscope and stand density, vigorous L929 cells to be grown are paved with bottom of bottle Afterwards, nutrient solution is discarded, is washed 2 times with PBS liquid, 0.25% pancreatin is added and digests 1 minute or so.

3) after Microscopic observation cell rounding takes off wall, add nutrient solution and terminate digestion.

4) to blow and beat nutrient solution with suction pipe uniform to cell distribution, carries out cell count using cell counting count board and takes average 3 times, Appropriate nutrient solution is supplemented, is configured to concentration about 2 × 10⁵/ ml cell suspension.

3. morphological observation

1) 1 piece of 6 hole steril cell culture plate is taken, test group ULWPE leaching liquors 1ml, negative control group UHMWPE are extracted The liquid 1ml and phenol solution 1ml of positive controls 0.64%, it is respectively placed in different holes in (every group of each 2 hole).

2) cell concentration is added per hole as 2 × 10⁵/ ml L929 cell suspension 1ml, are placed in 37 DEG C, volume fraction 5% CO₂Cell culture incubator culture.Cellular morphology and growing state and taken a picture after observing 12,24h under inverted microscope.Cellular morphology Analytical standard is as shown in table 1：

The cellular morphology analytical standard of table 1

4.CCK-8 colorimetric tests

1) cell suspension is diluted to 5 × 104/ml, is inoculated in 3 piece of 96 well culture plate, per the hole of plate spaced inoculations 30, point examination Three groups of group, negative control group and positive controls are tested, every group of 10 holes, 100 μ L is inoculated with per hole, are placed in 37 DEG C, 5%CO₂, 100% Preculture 24h in the cell culture incubator of humidity.

2) after cell attachment, original fluid is abandoned in suction, is washed 2 times with PBS.Test group adds 20%ULWPE leaching liquors 100 μ L, negative control group add the μ L of UHMWPE leaching liquors 100, and positive controls add the μ L of 0.64% phenol solution 100, in old terms Under cell culture incubator in (37 DEG C, 5%CO₂, 100% humidity) continue to cultivate.

3) it is each after cell inoculated and cultured 24,48,72h to take out 1 piece of culture plate progress CCK-8 colorimetric test.

4) inhaled at each time point and abandon original fluid, washed 2 times with PBS, test group adds 10 μ L CCK-8 reagents+90 per hole μ L ULWPE leaching liquors, negative control group add the μ L UHMWPE leaching liquors of 10 μ L CCK-8 reagents+90, and positive controls add The μ L of 10 μ L CCK-8 reagents+90 0.64% phenol solution.

5) culture plate is again placed in 37 DEG C, 5%CO₂, 100% humidity cell culture incubator in continue be incubated 3h after terminate Culture.

6) determined per hole light absorbs angle value (OD), be averaged under 450nm wavelength with ELIASA (SpectraMax 190) Value is used as its OD value result.

5. Cytotoxic evaluation

The relative proliferation rate (relative growth rate, RGR) of cell is calculated according to cell proliferation rate method, is carried out thin The evaluation of result of cellular toxicity.According to cell RGR values, Materials Cell toxicity grading (cytoxicity is carried out using 0~V grade of system Scale, CTS), the cytotoxicity grade of judgement ULWPE materials, RGR >=75% represents material without obvious cytotoxicity.Cell phase To proliferation rate (RGR)=(mean OD value of test group mean OD value/negative control group) x100%.Cytotoxicity grading evaluation mark It is accurate as shown in table 2：

The cytotoxicity grade scale of table 2

(2) Hemocompatibility Tests (hemolytic test)

According to " GB/T 16886.4-2003/ISO 10993-4:The part of 2002 BiologicalEvaluationofMedicalDevice the 4th：With blood The standard of liquid phase interaction experiment selection ", choose the blood compatibility of hemolytic test evaluation ULWPE materials.

1) fresh anti-freezing rabbit blood 8ml is extracted, it is stand-by to add physiological saline 10ml dilutions.

2) 9 clean tubes are taken to be divided into test group, positive controls and negative control group, every group 3.

3) test group adds 10ml materials leaching liquor (from 0.9% physiological saline extraction 72h, method is same as above), positive right 10ml distilled water is added according to group, negative control group adds 0.9% physiological saline 10ml.

4) test tube is put into 37 DEG C of water baths after pre-temperature 30min, is separately added into dilution anti-freezing rabbit blood 0.2ml, continues 37 After DEG C water-bath 1h, visually observe and whether there is haemolysis.The clear and bright red of solution in pipe, ttom of pipe remain without red blood cell, are judged as haemolysis.

5) by each pipe solution centrifugal 5min (2000r/min), 5 parts of each pipes of supernatant replication are taken to exist respectively from often pipe Absorbance (ELIASAs of SpectraMax 190) at 545nm, with the mean value computation percentage of hemolysis for repeating test value：Hemolysis rate (%)=(test material absorbance-negative control absorbance)/(positive control absorbance-negative control absorbance) × 100%. Positive control absorbance should be 0.8 ± 0.3, and negative control pipe absorbance answers≤0.03.

(3) acute systemic toxicity (through abdominal cavity injecting pathway)

According to " GB/T16886.11:2003/ISO 10993-11:The part of 1999 BiologicalEvaluationofMedicalDevice the 11st：Entirely The standard of body toxicity test " is tested.

1) 30 SPF level kunming mices are selected, average weight (22.4 ± 1.5) g, male and female half and half, are randomly divided into test group And control group, every group 15.

2) respectively to the material leaching liquor of test group mouse peritoneal injection 20%, dosage 50ml/kg, to control group mice abdomen Chamber injects 0.9% physiological saline of same dose.

3) after observation injection at once, after 4h, 24h, 48h and 72h, the ordinary circumstance such as two groups of mouse breathings, diet, urine and stool and Whether there is vomiting, diarrhoea, convulsions, the poisoning manifestations such as gait is unbalance and carry out classified estimation, animal clinical toxic reaction is classified and commented Estimate standard and be shown in Table 3.

4) dead mouse number and changes of weight are recorded.

The animal clinical toxic reaction grade scale of table 3

(4) muscle implantation test and Chronic Liver renal toxicity test

According to " GB/T16886.6：2003/ISO 10993-6:The part of 1999 BiologicalEvaluationofMedicalDevice the 6th：Implantation The requirement of local reaction experiment afterwards " carries out muscle implantation test, the chronic systemic toxicity test according to as defined in GB/T16886.11 It is required that carry out Chronic Liver renal toxicity test research.

1) SPF level SD rats 20, pre-operative anxiety water 6h are chosen.

2) after with the success of 3% Nembutal sodium solution intraperitoneal injection of anesthesia (30mg/kg), dorsal body setae is shaved, local alcohol disappears Poison.

3) lumbar spine to coccyx Posterior midline approach is taken to be about 2cm, it is blunt along gluteus maximus muscle fibre long axis direction with haemostatic clamp Property separation epimysium and muscle fibre, form muscular lacuna.

4) each 1 piece of ULWPE, UHMWPE (diameter 2mm, the high 5mm cylinders of sterilizing are implanted into respectively in left and right side lacuna Body), suture epimysium and skin.Postoperative intraperitoneal injection Benzylpenicillin sodium salt 1 time (80,000 U/ are only), in BJ Union Hospital's zoopery Center routine feeding.

5) postoperative ordinary circumstance observation：Rats death rate, feed, activity and otch whether there is redness and the infection conditions such as ooze out.

6) 5 rats are respectively put to death within postoperative 1,4,12,26 week and are drawn materials, naked eyes gross examination of skeletal muscle implantation material part meat color Change, whether there is congestion and edema adhesion, suppurate and ooze out and material discharge, material and surrounding flesh bag and fibrous capsule whether there is mobility and Coating formational situation etc..

7) liver of 5 rats, kidney device is taken to carry out visually observing parallel paraffin check pathological section during 12 weeks after operation.

8) implantation material is completely cut together with the gluteus of surrounding, with 4% paraformaldehyde -0.1%PBS buffer solutions by sample It is fixed, in department of pathology of Union Medical College Institute of Basic Medical Sciences, Beijing row FFPE, conventional section, hematoxylin-eosin (HE) dye.Light Microscopic observation surrounding materials intramuscular cell infiltration situation, whether there is fiber blister cavities coating and formed and into fiber Hyperplasia situation.

(5) statistical analysis

All continuous datas are represented in the form of mean ± standard deviation (x ± s), are entered using the statistics software bags of SPSS 16.0 Row data processing, data carry out independent samples t test, P between group<0.05 is statistically significant for difference.

3rd, result

(1) external acute cytotoxicity experiment

1. morphological observation

As shown in figure 1, after inoculated and cultured 12h and 24h, observation under the microscope finds test group (Fig. 1-A, 1-B) cell Form is substantially the same with negative control group (Fig. 1-C, 1-D), and L929 cell attachment well-growns, form is homogeneous, in long shuttle or more Angular, cell refractivity is strong, and cell body is plentiful, and cytoplasm is evenly distributed, and has circular somatoblast, acellular dissolving, cell Aging and abnormal differentiation, show the material no cytotoxicity；Positive controls (Fig. 1-E, 1-F) L929 cells destroy completely, carefully Born of the same parents' floating that comes off is rounded, and space between cells and cell surface spread a large amount of yellowish-brown fine particles, final cell rupture necrosis, present Obvious cytotoxicity.

2. cytotoxicity analysis

By CCK-8 colorimetrics, ELIASA measure at tri- time points of 24h, 48h, 72h each group under 450nm wavelength OD values, average as its OD value result, calculate cell with respect to proliferation rate (RGR).As shown in table 4, test group L929 cells It is respectively 95.25%, 104.96%, 102.81% in 24h, 48h, 72h RGR, shows test group ULWPE leaching liquors without obvious Cytotoxicity.

The each group cell of table 4 with respect to proliferation rate and cytotoxicity classification (N=10)

(note：Using the cell of ULWPE leaching liquor cultures as test group, using the cell of UHMWPE leaching liquor cultures to be negative right According to group, using the cell of 0.64% phenol solution culture as positive controls.As a result show test group ULWPE leaching liquors without obvious thin Cellular toxicity.)

(2) Hemocompatibility Tests (hemolytic test)

According to GB/T 16886.4-2003 standards, if hemolysis rate≤5% of material, it is molten to illustrate that material meets medical material The requirement of blood test, if>5% prompting material has haemocylolysis.

Each group test tube visually observes discovery after centrifugation, and the pipe solution of positive controls 3 is in clear and bright red, and ttom of pipe is without red thin Born of the same parents remain, and are judged as there is haemolysis.Test group and negative control group red blood cell are all sunk to the bottom, and supernatant achromaticity and clarification, are shown Without haemolysis.

Each group absorbance is shown in Table 5, calculate ULWPE materials hemolysis rate be 0.81%<5%, judge the leaching of ULWPE materials Extract is without haemocylolysis.

The hemolytic test absorbance testing result of table 5 (N=3)

(note：Calculate ULWPE materials hemolysis rate be 0.81%<5%, judge ULWPE materials without haemocylolysis.)

(3) acute systemic toxicity (through abdominal cavity injecting pathway)

After injection at once, 4h, 24h, 48h and 72h when, test group and control group mice do not occur motion reduce, eye Ptosis, expiratory dyspnea, diarrhoea, cyanosis or poisoning symptom or the adverse reaction such as tremble, none occurs dead.Two groups of mouse feeds Normally, reaction is quick, and body weight has different degrees of increase, and two groups are compared at same time point, and increased weight difference is examined through t No significant difference (P>0.05) table 6, is referred to.Result above shows the material without Acute systemic toxicity.

The mouse weight increment of table 6 and statistic analysis result (N=15, g)

(note：P>0.05, show ULWPE without Acute systemic toxicity.)

(4) intramuscular implantation local reaction experiment and Chronic Liver renal toxicity test

1. intramuscular implantation local reaction experiment

1) ordinary circumstance is observed

Experiment rat in postoperative 2~6h or so revival, progressively come into play.All rats survive, well-grown, back Operation on skin otch without it is red and swollen, ooze out and the inflammation sign such as suppurate, equal first intention, two kinds of surrounding materials are without suppurative infection, flesh Phenomena such as meat necrosis and implant are discharged.

2) pathological study

After implantation during 1 week materials, two kinds of materials mobility in flesh bag is larger, and meat color is scarlet, local without purulence point Secretion.See that surrounding materials intramuscular has massive inflammatory cells infiltrated under light microscopic, based on neutrophil leucocyte.Musculature is without deformation Necrosis, no fibrous capsule form (Fig. 2-A, 2-B).4 weeks after implantation, material basic non-activity in flesh bag, see that inflammatory is thin under mirror Born of the same parents are reduced earlier above, are had fibroblast and angioblast propagation, are formed loose, became uneven fibrous capsule (Fig. 2-C, 2- D), there are a small amount of neutrophil leucocyte, lymphocytic infiltration in coating.12 weeks after implantation, material is not degraded, tight with surrounding tissue Close adhesion, the non-activity in flesh bag, local secretion without exception.See that inflammatory cell is most under mirror to disappear, have complete and fine and close Fibrous connective tissue coating forms (Fig. 2-E, 2-F), and coating is mainly made up of fibroblast and cytoplasm, and inflammatory cell is bright It is aobvious to reduce, have no foreign matter macrophage.26 weeks after implantation, two groups of materials have no inflammatory reaction, chronic granulo without degraded under mirror Hyperblastosis, surrounding materials fibrous capsule are similar to 12 weeks after operation (Fig. 2-G, 2-H).Same time point compare two kinds of storerooms without Notable difference.

2. Chronic Liver renal toxicity test

Material is implanted into after 12 weeks, takes out liver, the kidney device of experiment rat.Visually observe and see liver and kidney size, form, color Pool, quality are normal, and with surrounding tissue without adhesion, surface is without hardening, tubercle and congestion and edema.Paraffin pathological examination such as Fig. 3 institutes Show, liver cell becomes without oedema and fat, and portal area is without bile duct proliferation；Glomerulus has no mesangial matrix *, without cast, interstitial in tubule Interior no inflammatory reaction.The above results show ULWPE without Chronic Liver renal toxicity.

The ultra-low abrasion polyethylene bio-tribology performance study of embodiment 3

First, material and equipment

(1) test material

1.ULWPE pins are made by the resulting materials of embodiment 1, import CPE, HXLPE bar (German MediTECH medicine equipments Company) provided by Beijing Chunli Zhengda Medical Equipment Co., Ltd. and be responsible for the pin sample that processing prepares three kinds of materials. Every kind of material respectively prepares 3 samples, is diameter 6mm, height 25mm cylinder, sanding and polishing to specimen surface roughness Ra <0.02 μm, the end face each sold is poured out 30 ° of fillets.Due to the presence of fillet, contact area is gradually to become in experimentation It is big, and pressure tapers into, this with prosthese under arms during being gradually reduced for pressure be consistent.

2. cobalt chrome molybdenum disk (CoCrMo Disc)

Vitallium often cooperatively forms kinematic pair, this experiment CoCrMo alloys in joint prosthesis with polythene material Rosette is prepared, friction pair is formed with ULWPE.Sample is provided by Beijing Chunli Zhengda Medical Equipment Co., Ltd., Cut by CoCrMo alloy bar materials and be processed into disk.Totally 3, be diameter 90mm, thickness 25mm cylinder.With the present invention ULWPE web contacts face is first ground with grinder, is then ground with the sand paper that granularity is 1200 and 2400, finally again respectively with 6 μ M and 1 μm of diamond paste is polished to surface roughness Ra<0.02μm.

3. simulated body fluid lubricates

In experiment, according to ASTM F732-00 standards, using calf serum (GIBCO, numbering：16010-159；Lot number： 1128145) lubricant environment of joint prosthesis in vivo is simulated.For except the impurity in serum deprivation, with the limited public affairs of Hangzhou special type paper industry The chronic filter paper of department filters to it, and presses 1 to serum:1 ratio is diluted with distilled water.The knot of each stage of experiment Used calf serum will be changed after beam.

(2) abrasion testing apparatus

1.BiotriboPOD Type Zero friction wear testing machines

The friction-wear test equipment that this experiment uses is medical embedded material tailored version friction wear testing machine (BiotriboPOD Type Zero), the equipment had carried out a series of experiment, and what its result demonstrated the testing machine can By property.

2. wear weight measurement instrument

The balance weighed in experiment to pin sample is the CP Series Precision electronics produced by German Sartorius companies Balance, model CP225D.

3. Analysis of Surface Topography

The LEICA DM 2500M upright metallurgical microscopes of German LEICA companies are selected in the experiment.

4. drying box

, it is necessary to be dried using drying box after pin sample cleans, to remove the moisture of the inside.Drying box is Shanghai The electric heating constant-temperature blowing drying box of leap Medical Devices Co., Ltd., model GEX-GF-MBS.

2nd, test method

ASTM F732-00 and ASTM of the operation of pin-on-disc friction wear experiment with reference to American Society Testing and Materials G99-04a standards perform.

(2) phenetic analysis is worn

1. wear quality determination

Pin sample is first cleaned before the test：First rinsed with running water, the then ultrasonic wave cleaning 15 under 1% liquid detergent Minute.Cleaned with deionized water after taking-up, then cleaned 15 minutes with ultrasonic wave, then with deionized water rinsing, downless Drying box dries half an hour.Soak 3 minutes in absolute alcohol after taking-up, dry again, drying temperature is 45 DEG C.Above-mentioned steps After the completion of, pin sample is positioned in dustfree environment 24 hours at room temperature, then weighed.

Suspend every 500,000 cycles and test, then remove pin sample and clean, electronic balance is used after drying box drying Sample weight is weighed, the weight of sample is sold before record experiment and after experiment, the measurement accuracy of electronic balance is 0.01mg, because should Balance has certain error (0.02mg), therefore each pin sample is weighed 5 times, then takes the average value of 5 readings.Per the stage Experiment pin sample will be weighed before proceeding.

2. Analysis of Surface Topography

Every 500,000 cycles, after pin sample of weighing, its wear surface is observed.First seen with 5 times of object lens Survey, be so advantageous to quickly find the abration position for wanting observation and observe the more macroscopical pattern of wear surface, each sell sample Will successively with 5 ×, 10 × and 20 × tri- kind of object lens observation.By the observation software being connected with microscope, shooting is more macroscopical Wear map picture.Object lens are rotated, observe and shoot more microcosmic worn surface successively.

(3) test preparation calf serum

The calf serum of 500ml dresses is taken out from refrigerator (- 10 DEG C), puts and thaws at normal temperatures.After defrosting, 50ml is poured out Calf serum is into glass beaker.Glass bar, filter paper and plastic beaker are taken out, the serum in glass beaker is filled into plastics burns In cup.The distilled water with post-filtered sera same amount is measured with graduated cylinder, by 1:1 ratio is mixed with.It is equal with glass bar stirring It is even then standby with tinfoil sealing.

(4) installation of pin and disk

The parts of the fixture on testing machine, key are cleaned, be cleaned before experiment, so as to eliminate greasy dirt, particle The factor that thing etc. may impact to experimental result.

Disk is placed on the inside of chuck, then the helicla flute of rotary chuck is so as to by chuck clamping.3 pin samples are put into successively Sell in fixture, the nut above alignment jig, make pin and disk good contact.Take out 50% calf serum prepared, Ran Houhuan Slowly pour into disk, afterwards sealed disk and pin with hermetic bag, prevent dust from entering and the evaporation of moisture can be reduced.Adjust light The contact position of electric transducer, it is ensured that sensor can delicately capture the change of motion tray position.It is complete in above step Into afterwards, dust cover is covered.

(5) data processing method

Correlative study shows that testing machine often operates 1,000,000 turns and moved equivalent to joint prosthesis friction pair in human body 1 year Motion, its degree of wear commonly uses clinical wear rate (wearrate) and wear factor (wear factor) to represent.Hip is closed For saving prosthese, clinical wear rate has reacted artificial joint prosthesis and the size of the degree of wear caused by femur acetabular bone, Ke Yiyou The effect of effect ground evaluation joint material or artificial prosthesis are to patient.

1. wear rate (wearrate)

Wear rate (I) refers to the volume wear (Δ V) of material in the unit interval.

The calculation formula of wear rate is：I=Δ m/ ρ

Wherein, Δ m is the wear extent (mg) in a unit interval, and ρ is density of material (mg/mm³).This experiment is by 100 Ten thousand cycles are defined as a unit interval.

2. abrasion factor (wear factor)

Wear factor (K) illustrates material volume wear in the case of specific loading (F) and unit sliding distance (S) Loss, it has important application in the wearability of relatively different materials.

The calculation formula of wear factor is：K=Δs V/FS

Wherein, Δ V is wear volume, namely wear rate；F is the normal load (N) that material is born；S is that tested sample exists Coasting distance (m) in wear process.Δ V=Δs m/ ρ, unit mm³, the unit of wear factor is mm³/N·m。

3rd, result

(1) wear extent

Abrasion quality measurements when rubbing 500,000,1,000,000,1,500,000 and 2,000,000 cycle, as a result find ULWPE's Abrasion quality is minimum, and HXLPE takes second place, CPE highests.

Table 7 is that ULWPE, HXLPE, CPE sell wear extent of the sample when rubbing 500,000,1,000,000,1,500,000 and 2,000,000 cycle Result of calculation.

7 three kinds of material pin sample abrasion quality results of table (mg)

(2) wear rate

The density of three of the above material is about 0.94mg/mm³, the wear rate that three kinds of materials are calculated is as shown in table 8.Knot Fruit shows that ULWPE wear rate is minimum, and HXLPE takes second place, CPE highests.

Wear rate (the mm of 8 three kinds of material pin samples of table³/ million times)

(3) abrasion factor

The wear factor that three kinds of materials are calculated according to formula is as shown in table 9.As a result show, ULWPE wear factor Minimum, HXLPE takes second place, CPE highests.ULWPE is after the test of 2,000,000 cycles, wear extent 0.805mg, wear factor 1.945 ×10^-6mm³/ Nm, significantly lower than HXLPE (4.16 × 10^-6mm³/ Nm) and CPE (8.62 × 10^-6mm³/N·m)。

Wear factor (the mm of 9 three kinds of material pin samples of table³/N·m)

(4) grinding defect morphology

Before experiment, the sample that three kinds of materials are made carries out hand polish with polishing machine.Treated three kinds of material surfaces Pattern is basically identical, only some cutter trades that are tiny, being evenly distributed.

Compare wear morphology of three kinds of materials after 500,000 times, 1,000,000 times, 1,500,000 times and 2,000,000 times circulations.It can see Go out, the wear morphologies of 3 of same group of CPE material pin sample friction surfaces are similar, with some loose fibers, surface hollow and white Based on color spot point；3 pin samples of same group of HXLPE material are based on chill mark and shallower ditch dug with a plow；Same group of ULWPE material Three pin samples of material are based on shallower ditch dug with a plow and surface scratch.

Compared with CPE materials, HXLPE can also produce surface polishing effect.But because its hardness increases after crosslinking with radiation Greatly, therefore abrasive wear can be produced, wear surface is produced scratch and shallower ditch dug with a plow.This is mainly due to by cross-linking modified Though HXLPE materials be improved in terms of abrasion resistance properties, modified HXLPE has substantial amounts of free radical, i.e., Make to be completely eliminated by certain heat treatment, the free radical of these residuals will be aoxidized progressively, make material office Portion produces fragility.This mechanical deficiencies of the material, which add issuable hard particles in the progress of material wear, becomes stress Concentrated source, caused stress concentration cause surrounding materials that plastic deformation and Plastic Flow occurs.In the effect of loop cycle load Under, stress concentration and Plastic Flow can be more long-pending bigger, cause at hard particles or fault location produces fatigue crack.

ULWPE material surfaces are similarly subjected to grind the influence of effect, show partially polished phenomenon, this illustrates such The wear form of material and CPE materials are similar.Its wear surface caused by abrasive wear ditch dug with a plow and surface scratch relative to HXLPE is less.But for wear extent and wear factor, it is less than CPE and HXLPE, the discovery is from bio-tribology angle This kind of material of upper explanation possesses the Potential feasibility for substituting original superhigh molecular weight polyethylene material.

Although above the present invention is described in detail with a general description of the specific embodiments, On the basis of the present invention, it can be made some modifications or improvements, this will be apparent to those skilled in the art.Cause This, these modifications or improvements, belong to the scope of protection of present invention without departing from theon the basis of the spirit of the present invention.

Claims

A kind of 1. application of ultra-low abrasion polyethylene in artificial joint prosthesis.
2. application as claimed in claim 1, it is characterised in that the ultra-low abrasion polyethylene is to use special transition metal list Activated centre coordination polymerization catalysts, a kind of weight average molecular weight prepared under gentle polymerization process condition 40~700,000 it Between, narrow ditribution Alathon of the molecular weight distribution between 2.0~3.5.
3. application as claimed in claim 2, it is characterised in that the ultra-low abrasion polyethylene is by being included in support type cyclopentadienyl In the presence of metallic catalyst and the second alkylaluminoxane, ethene progress slurry polymerization is prepared, wherein, the load Type metallocene catalyst includes metallocene compound, alkyl aluminum and the first alkyl alumina of carrier and load on the carrier Alkane, the metallocene compound are rac-R¹ ₂-Si(2-R²-4-Ar-Ind)₂MX₂, R¹And R²Respectively C₁-C₅Alkyl in one Kind, Ar is aryl, and Ind is indenyl, and M is one kind in titanium, zirconium and hafnium, and X is one kind in halogen.
4. a kind of artificial joint component, it is characterised in that the artificial joint component is passed through by ultra-low abrasion polythene material Certain chemically or physically method processing forms.
5. artificial joint component as claimed in claim 4, it is characterised in that the ultra-low abrasion polyethylene is using at radiation Reason method increases crosslinking rate, and the space structure of ULWPE molecules changes under specially 1~200kGY x ray irradiation xs, caused Free radical is bound to each other to form lateral covalent bond, makes ULWPE molecules aligns more multidirectional.
6. the artificial joint component as described in claim 4 or 5, it is characterised in that the ultra-low abrasion polyethylene is also using multiple Close antioxidant mode and be eliminated as much as free radical in material.
7. artificial joint component as claimed in claim 6, it is characterised in that the composite antioxidant be 0.06%~ 0.08% natural vitamin E.
A kind of 8. artificial joint prosthesis, it is characterised in that the artificial joint prosthesis be processed by the artificial joint component and Into it includes any artificial organs that can be used for operation auxiliary treatment, such as artificial knee joint, fixture, joint simulator, artificial lining Pad.
9. a kind of artificial joint prosthesis, it is characterised in that beaten by the ultra-low abrasion polyethylene injection molding after processing or 3D It is printed as type.