局部緩釋藥丸防治開(kāi)放性骨折感染的實(shí)驗(yàn)研究.doc

局部緩釋藥丸防治開(kāi)放性骨折感染的實(shí)驗(yàn)研究更新日期：2010-09-08 吳宏斌鄭啟新徐逢仁李世譜劉暢閻玉華 【摘要】目的局部植入緩釋藥丸防治開(kāi)放性骨折骨及軟組織感染。方法用可降解人工骨移植材料磷酸三鈣承載第三代喹喏酮類廣譜抗生素環(huán)丙沙星制成磷酸三鈣/環(huán)丙沙星緩釋藥丸(TCDC)并檢測(cè)其體外抑菌能力及植入兔股骨大轉(zhuǎn)子后釋藥情況。結(jié)果TCDC對(duì)金葡菌、大腸桿菌、綠膿桿菌等骨科感染常見(jiàn)致病菌有強(qiáng)大且持久的抑菌能力,持續(xù)時(shí)間分別大于5、51天,等于27天。TCDC周圍骨及肌肉組織能長(zhǎng)期(大于30天)保持較高藥物濃度,而血中濃度極低且呈逐漸下降趨勢(shì)。結(jié)論TCDC具有防治開(kāi)放性骨折感染的良好前景。 【關(guān)鍵詞】磷酸三鈣環(huán)丙沙星骨折,開(kāi)放性感染 Experimental Study on Local Drug Delivery System for Treatment of Open FracturesWU Hong-bin, ZHENG Qi-xing, XU Feng-ren, et al. Emergency Center of Union Hospital, Tongji Medical University, Wuhan 430022 【Abstract】AimDrug delivery system (DDS) was adopted for the prophylaxis and treatment of osteomyelitis and soft tissue infection after open fractures. MethodsWe prepared a new DDS, tricalcium phosphate/ciprofloxacine delivery capsule (TCDC) by loading broadspectrum antibiotic: ciprofloxacine into the cylindrical cavity of biodegradable bone substitute tricalcium phosphate (TCP) and TCDCS bacteriostasis ability in vitro and in vivo were also tested. ResultsTCDC showed great and lasting bacteriostasis to common pathogens of orthopaedic infections, such as staphylococcus aureus, escherichia coli and pseudomonas aeruginosa, with bacteriostasis lasting more than 5 days, 51 days and 27 days respectively. In vivo study showed that high concentration of ciprofloxacine still occurred in the bone and muscle tissues surrounding TCDC which was placed in the great trochanter of rabbit and that it continued to let off ciprofloxacine for at least 30 days, while the concentration of ciprofloxacine in blood was very low and tended to reduce gradually. ConclusionTCDC can sustain a high local antibiotic concentration while the blood antibiotic concentration is very low. It may become a good method to treat infections after open fractures. 【Key words】Tricalcium phosphateCiprofloxacineOpen fractureInfection 開(kāi)放性骨折較易并發(fā)軟組織感染及骨髓炎,嚴(yán)重感染常會(huì)影響骨折愈合。如何防治這類感染,一直是臨床醫(yī)師頗為關(guān)切的問(wèn)題。Henry等將載抗生素的聚甲基丙烯酸甲酯(polymethylemethacrylate, PMMA)藥丸置入骨折部,在臨床上取得了良好的防治感染效果1。Rethman則用聚乙烯酸/聚乳酸共聚物(polyglycolic acid/polylactic acid copolymer)承載抗生素治療鼠股骨干骨折合并金葡菌感染,亦獲成功2。筆者用磷酸三鈣承載廣譜抗生素環(huán)丙沙星制成磷酸三鈣/環(huán)丙沙星緩釋藥丸(tricalciurm phosphate/ciprofloxacine delivervy capsule, TCDC),并對(duì)其體內(nèi)、外的釋藥情況進(jìn)行了研究。 材料與方法 一、TCDC的制備 分析純CaHPO4.2H2O和CaCO3粉末按一定比例充分混勻后,常壓下升溫致960,保溫2小時(shí)再冷卻成TCDC原料粉備用。選擇以P2O5-CaO為主要成份的低融點(diǎn)玻璃為高溫粘結(jié)劑,以重量比為167的比例與TCDC原料粉充分混勻、烘干,再加入40%左右溶融的石蠟作為成孔劑,充分拌合后,注入藥囊模具成型,藥丸分中空?qǐng)A柱狀主體和尾蓋兩部分(圖1)。藥丸內(nèi)徑2mm、長(zhǎng)8mm、壁厚1mm。將成型后的坯體放入高溫爐內(nèi)埋燒,排蠟和燒成一次完成。排蠟在200500間進(jìn)行,燒成溫度為900,在900保溫2小時(shí)后隨爐冷卻,將燒成的藥丸裝載8mg鹽酸環(huán)丙沙星藥粉,并用-磷酸三鈣骨水泥(-TCP)將尾蓋與主體封合在一起。 圖1TCDC藥丸分中空?qǐng)A柱狀主體與尾蓋兩部分,裝藥后用-TCP骨水泥封合在一起 二、體外抑菌實(shí)驗(yàn) 將160高溫消毒2小時(shí)的TCDC3粒,在無(wú)菌操作下分別置于接種有金葡菌、綠膿桿菌、大腸桿菌的瓊脂培養(yǎng)基中央;另用160高溫消毒2小時(shí)未裝藥的TCP空藥丸,亦分別置于接種有上述3種細(xì)菌的培養(yǎng)基中央作為對(duì)照。實(shí)驗(yàn)組及對(duì)照組培養(yǎng)基均置于37溫箱。24小時(shí)后記錄抑菌情況。72小時(shí)后將所有TCDC及TCP空藥丸重新轉(zhuǎn)入新的接種有相應(yīng)菌種的培養(yǎng)基中,置37溫箱,繼續(xù)觀察抑菌情況,如此反復(fù)轉(zhuǎn)培17次,共觀察57天。上述所有標(biāo)準(zhǔn)菌種為同濟(jì)醫(yī)科大學(xué)附屬協(xié)和醫(yī)院檢驗(yàn)科提供。 三、體內(nèi)釋藥實(shí)驗(yàn) 1.同濟(jì)醫(yī)科大學(xué)動(dòng)物中心提供的大耳白兔8只(雌兔5只、雄兔3只),體重22.5kg。846合劑肌肉麻醉后,于無(wú)菌條件下手術(shù)暴露雙側(cè)股骨大轉(zhuǎn)子,每側(cè)鉆兩個(gè)直徑4mm,深67mm的骨腔,兩腔相距約2mm,每個(gè)骨腔植入TCDC1粒。TCDC約3/4植入骨腔內(nèi),約1/4留于腔外用肌肉組織包裹。每側(cè)股骨轉(zhuǎn)子區(qū)植入TCDC2粒,雙側(cè)共4粒。植入后1、2、3、4、5、7、9、12天從兔耳緣靜脈采血2ml,并于第9、16、23、30天分別處死兔2只。處死前耳緣靜脈采血2ml,處死后取緊鄰植入體的骨和肌肉各500700mg。用日本島津公司產(chǎn)HPLC-型高效液相色譜儀檢測(cè)血及組織中環(huán)丙沙星濃度。 2.將植入兔股骨轉(zhuǎn)子區(qū)30天后的TCDC取出,置入接種有金葡菌的瓊脂培養(yǎng)基中央,37溫箱培養(yǎng)24小時(shí)后觀察抑菌情況。 結(jié)果 一、掃描電鏡觀察TCP載體材料的橫斷面形貌 圖2可見(jiàn)載體壁具有分布均勻的連通氣孔。圖3可見(jiàn)清晰的連通氣孔?？妆诰w發(fā)育不均勻,多為不規(guī)則形。測(cè)量氣孔孔徑一般在30m左右。 圖2TCDC壁具有分布均勻的連通氣孔,藥物微粒通過(guò) 這些微孔緩慢釋出SEM1000 圖3TCDC壁中,孔壁晶體發(fā)育不均,多不規(guī)則, 測(cè)量孔徑一般在30m左右SEM5000 二、體外抑菌實(shí)驗(yàn)結(jié)果 實(shí)驗(yàn)組TCDC有明顯抑菌圈,對(duì)照組TCP載體材料無(wú)抑菌作用,每種細(xì)菌的抑