殼聚糖對(duì)自制磷酸鈣骨水泥性能的影響

1、殼聚糖對(duì)自制磷酸鈣骨水泥性能的影響 07-08-25 17:24:00 編輯：studa20作者：潘朝暉，范清宇，蔡和平，馬保安，黃波，姜林莉，文艷華【關(guān)鍵詞】 ,磷酸鈣骨水泥 Effects of chitosan on properties of selfmade calcium phosphate cement【Abstract】 AIM: To investigate the effect of chitosan on the physical characteristics, ultramicrostructure and biocompatibility of a selfmade

2、 calcium phosphate cement (CPC). METHODS: Two different cement formulations were prepared by mixing CPC powder respectively with 50 g/L chitosan lactate and 1 mol/L dibasic sodium phosphate used as liquid phase. For physical properties, washout resistance, primary setting time and compressive streng

3、th were measured. Scanning electron microscopy (SEM) was used to examine the microstructure and the intramuscular implantation of a rat model and rat mesenchymal stem cells (RMSC) seeded on CPC disks were used to compare the biocompatibility of the two formulations. RESULTS: CPCchitosan composite wa

4、s more stable in water than conventional CPC and it did not disintegrate within 3 min even when placed in water immediately after the mixing. The mean setting time was 8.38 min in CPCchitosan and 23.68 min in the control. The mean compressive strength of composite increased to 6.52 MPa, whereas the

5、control samples exhibited much lower values (2.08 MPa). SEM examinations showed that globular and platy particles were formed on surfaces of all samples but the particles on the surface of the CPCchitosan composite seemed to connect together viscously, with smaller pores than those of control. Sligh

6、t signs of inflammation, which disappeared after four weeks, were detectable around the specimens implanted within one week. After 12 weeks, the experimental implants became soft, while the controls remained the same in appearance. Necrosis was not detected in the muscles around the implants. SEM sh

7、owed that cells adhered to CPCchitosan composite disks, but the visible amount of the adherent cells was greater than that of control. CONCLUSION: Chitosan is suitable for the stabilization of CPC in a wet environment for it accelerates the setting reaction and improves the mechanical properties and

8、 biocompatibility of the cements.【Keywords】 calcium phosphate cement； chitosan； compressive strength； biocompatibility【摘要】 目的：了解殼聚糖對(duì)自制磷酸鈣骨水泥（CPC）物理性能、超微結(jié)構(gòu)及生物相容性的影響. 方法：分別以50 g/L乳酸殼聚糖和1 mol/L磷酸氫二鈉為液相制備CPC試樣，通過防水試驗(yàn)、測(cè)定初步凝結(jié)時(shí)間、抗壓強(qiáng)度；掃描電鏡觀察凝固體超微形態(tài)；大鼠肌肉植入及骨髓基質(zhì)干細(xì)胞表面種植試驗(yàn)比較兩者差異. 結(jié)果：復(fù)合殼聚糖的CPC在水中更穩(wěn)定，混合后即刻投入生理鹽水3

9、 min內(nèi)不散開；平均初步凝結(jié)時(shí)間8.38 min，對(duì)照組23.68 min；平均抗壓強(qiáng)度6.52 MPa；對(duì)照組2.08 MPa. 掃描電鏡發(fā)現(xiàn)凝固體表面為顆粒狀及片狀晶體，實(shí)驗(yàn)組晶體互相連接，孔隙較對(duì)照組少. 植入肌袋1 wk有輕微炎癥反應(yīng)，4 wk后反應(yīng)減退，12 wk后實(shí)驗(yàn)組材料變軟，對(duì)照組外形基本未變. 肌肉無壞死. 電鏡下細(xì)胞可在水泥盤上貼附、生長(zhǎng), 實(shí)驗(yàn)組可見的細(xì)胞數(shù)較多. 結(jié)論：CPC殼聚糖復(fù)合物在潮濕條件下更穩(wěn)定，固化時(shí)間縮短，抗壓強(qiáng)度提高，生物相容性更好.【關(guān)鍵詞】 磷酸鈣骨水泥；殼聚糖；抗壓強(qiáng)度；生物相容性0引言骨缺損是困擾矯形、頜面、腦外科的一個(gè)常見而又棘手的難題. 自

10、固化磷酸鈣骨水泥（calcium phosphate cement, CPC）終產(chǎn)物的化學(xué)結(jié)構(gòu)與骨的礦物成份相似，具有良好的生物相容性、可降解性、骨傳導(dǎo)性，并且可隨意塑性，與周圍骨組織緊密連接等多種優(yōu)點(diǎn)1，因而得到材料界及醫(yī)學(xué)界的重視，成為骨缺損修復(fù)材料研究和應(yīng)用的一個(gè)熱點(diǎn). 但是普通CPC缺乏韌性、固化時(shí)間長(zhǎng)、降解速度較慢、抗壓強(qiáng)度低等不足使其臨床應(yīng)用受到一定限制. 如何進(jìn)一步改性，更好地滿足臨床需要成為研究的焦點(diǎn). 研究發(fā)現(xiàn)改變其固相顆粒大小、液相、液固比例、溫度，添加適當(dāng)?shù)挠袡C(jī)或聚合材料等方法可以在一定程度上改善其性能 2-5.殼聚糖（chitosan, CS）是地球上含量極為豐富，僅次

11、于纖維素的天然聚合體甲殼素的脫乙酰化衍生物，其結(jié)構(gòu)與硫酸軟骨素、透明質(zhì)酸等物質(zhì)類似，是一種由2氨基2脫氧葡萄糖通過1,4糖苷鍵聚合的天然聚陽離子多糖. 研究表明CS可被包括溶菌酶在內(nèi)的多種特異或者非特異性酶降解為氨基葡萄糖而被吸收，并且具有生物相容性、止血、抗感染、可塑性及黏附性等諸多優(yōu)點(diǎn)6， CS單獨(dú)或者與復(fù)合其他材料可制作敷料、釋放藥物、基因的載體、生物涂層、組織工程支架等7. 我們擬研究CS對(duì)自制的自固化CPC性能的影響.1材料和方法1.1CPCCS復(fù)合物的制備參照文獻(xiàn)8所述方法制備無水磷酸氫鈣和磷酸四鈣，球磨過篩，前者平均粒徑1 m，后者17 m. 等摩爾比混合作為CPC固相. 液相：

12、實(shí)驗(yàn)組50 g/L乳酸殼聚糖（上海源聚生物公司)，對(duì)照組1 mol/L磷酸氫二鈉. 粉(g)液(mL)=21.1.2防水試驗(yàn)用手將0.3 g CPC粉及0.15 mL液體揉合，作成小球，立即放入含4 mL 37生理鹽水內(nèi)的小瓶?jī)?nèi),比較肉眼可見的散開程度.1.3初步凝結(jié)時(shí)間測(cè)定0.6 g CPC粉與0.3 mL液體在玻璃板上混合30 s后，置入直徑5 mm高12 mm玻璃管內(nèi)，塑料膜覆蓋管頂及管底，C型夾固定，置于相對(duì)濕度100%，37濕盒內(nèi)，定期取出用水泥凝結(jié)時(shí)間測(cè)定儀（上海東星建材實(shí)驗(yàn)儀器有限公司）間隔不同時(shí)間測(cè)定. 從試針接觸試樣表面，讓滑桿自由滑下，至試針插入試樣不超過1 mm所需時(shí)間為

13、水泥初步凝結(jié)時(shí)間（n=5）.1.4抗壓強(qiáng)度測(cè)定標(biāo)準(zhǔn)抗壓試件為直徑比高度小于2的圓柱體. 0.6 g CPC粉與0.3 mL液體混合，裝入直徑5 mm高12 mm模具，直徑5.6 mm不銹鋼棒周期擠壓（壓力約19.6 N）. 脫模后，放入直徑8 mm高20 mm玻璃管內(nèi)，塑料膜封口， 37相對(duì)濕度100%的濕盒內(nèi)固化2 d. 標(biāo)本放在材料萬能試驗(yàn)機(jī)量壓縮頭之間，抗壓測(cè)試加載至試件變形，記錄最大壓力，計(jì)算抗壓強(qiáng)度（n=5）.1.5掃描電鏡分析樣品的形態(tài)力學(xué)測(cè)量后斷裂表面脫水干燥并經(jīng)真空鍍膜儀表面噴金，掃描電鏡(日產(chǎn)JSM35C型)觀察各樣本表面形態(tài).1.6肌肉植入試驗(yàn)0.2 g/L戊巴比妥鈉腹腔注射麻醉動(dòng)物后，背部正中縱行切口，小心分離脊柱兩側(cè)椎旁肌肉形成肌袋，各植入經(jīng)射線滅菌的實(shí)驗(yàn)及對(duì)照組水泥柱一枚，分別于術(shù)后1 wk，1 mo，3 mo照相、取材，40 g/L多聚甲醛緩沖固定液固定，常規(guī)石蠟包埋，切片，HE染色. 每組4只SD大鼠（第四軍醫(yī)大學(xué)實(shí)驗(yàn)動(dòng)物中心）.1.7細(xì)胞種植實(shí)驗(yàn)及對(duì)照組分別制備成直徑10 mm，厚4 mm 的水泥盤，固化48 h后乙醇漂洗2次，射線滅菌. 取成骨性培養(yǎng)基條件下培養(yǎng)的第2代