【摘要】：本實(shí)驗選用功率500W、頻率20kHz的探頭式超聲波反應(yīng)器,以蒸餾水為介質(zhì)制備了超聲改性淀粉。對實(shí)驗條件進(jìn)行了優(yōu)化,隨著超聲波處理時間的延長,淀粉的溶解率增加,溶液的溫度逐漸升高,最佳超聲處理時間為10mmin,制備改性淀粉時原淀粉乳質(zhì)量分?jǐn)?shù)為20%. 測定了改性淀粉的性質(zhì),改性淀粉的顆粒密度為838.64kg/m3,比原淀粉顆粒密度減小。改性淀粉糊化后透光率為55.85%,比原淀粉糊透光率增加。使用掃描電子顯微鏡觀察,發(fā)現(xiàn)超聲波處理并沒有改變淀粉顆粒的形狀,而是在光滑的顆粒表面形成了許多孔洞和凹坑。X射線衍射分析淀粉顆粒的晶體結(jié)構(gòu)表明,超聲波改變了淀粉顆粒的非結(jié)晶區(qū),沒有改變淀粉顆粒的結(jié)晶區(qū)。 制備了超聲改性淀粉/聚乙烯醇/海藻酸鈉復(fù)合微球,并優(yōu)化了實(shí)驗條件。改性淀粉質(zhì)量分?jǐn)?shù)4%,聚乙烯醇質(zhì)量分?jǐn)?shù)8%,海藻酸鈉質(zhì)量分?jǐn)?shù)為4%,氯化鈣的質(zhì)量分?jǐn)?shù)為5%時制備的復(fù)合微球的形態(tài)最好。最佳的干燥方式為先室溫干燥24h,再40℃烘箱干燥24h。超聲改性淀粉、聚乙烯醇、海藻酸鈉分子中都含有羥基,三元復(fù)合微球的紅外光譜圖顯示復(fù)合后在3400cm-1附近的-OH伸縮振動峰的峰寬變窄,說明游離羥基的數(shù)目變少,認(rèn)為三種原料之間有氫鍵形成。干燥前微球的平均粒徑約為3.08mmm,干燥后的復(fù)合微球的平均直徑約為1.03mm。微球的掃描電鏡圖顯示微球表面和剖面都有大量的縫隙和少量孔洞,內(nèi)外貫穿,有利于水分子的進(jìn)入和藥物的釋放。 測定了復(fù)合微球的性能。隨著復(fù)合微球中改性淀粉質(zhì)量分?jǐn)?shù)的增加,復(fù)合微球的含水率增加。復(fù)合微球在蒸餾水中浸泡2h達(dá)到溶脹平衡,溶脹倍率為160%。復(fù)合微球在pH為7.4的PBS緩沖液中可以緩慢降解,8h之后降解率為98.79%,在pH為1.2的鹽酸溶液和pH為7的蒸餾水中幾乎不降解。復(fù)合微球的降解液溶血率為2.32%,小于5%,說明復(fù)合微球不會引起溶血。用微球的降解液培養(yǎng)細(xì)胞,細(xì)胞的增殖未受到影響,說明復(fù)合微球的細(xì)胞相容性好。 以鹽酸四環(huán)素為模型藥物制備了載藥復(fù)合微球,隨著投藥量的增加,載藥率增大,包封率先增大,后又略微減小。鹽酸四環(huán)素載藥復(fù)合微球在pH為7.4的PBS緩沖液中進(jìn)行體外釋藥實(shí)驗,結(jié)果表明不同淀粉質(zhì)量分?jǐn)?shù)的載藥微球在350min內(nèi)均可以緩慢釋放出藥物,超聲改性淀粉的質(zhì)量分?jǐn)?shù)越大,藥物釋放速度越大。
[Abstract]:In this experiment, ultrasonic modified starch was prepared in a probe type ultrasonic reactor with power of 500W and frequency of 20kHz, and distilled water was used as the medium. The experimental conditions were optimized. With the prolongation of ultrasonic treatment time, the dissolution rate of starch increased, the temperature of solution gradually increased, the optimum ultrasonic treatment time was 10 m min, and the mass fraction of raw starch milk was 20% when the modified starch was prepared. The particle density of modified starch was 838.64 kg / m ~ (3), which was lower than that of original starch. The transmittance of modified starch paste is 55.85, which is higher than that of original starch paste. Using scanning electron microscope (SEM), it was found that ultrasonic treatment did not change the shape of starch particles, but formed many holes and pits on the smooth surface of starch particles. Ultrasonic wave changed the amorphous zone of starch granules, but did not change the crystalline region of starch granules. The ultrasonic modified starch / polyvinyl alcohol / sodium alginate composite microspheres were prepared and the experimental conditions were optimized. When the mass fraction of modified starch is 4, the mass fraction of polyvinyl alcohol is 8, the mass fraction of sodium alginate is 4, the mass fraction of calcium chloride is 5, the morphology of composite microspheres is the best. The best drying method is to dry at room temperature for 24 hours and then to dry at 40 鈩，

本文編號：2371446