粒细胞-巨噬细胞集落刺激因子微球制剂的体外释放研究

目的：开发一种粒细胞-巨噬细胞集落刺激因子（GM—CSF）长效缓释微球剂型。方法：采用S／O／hO法制备了包裹粒细胞一巨噬细胞集落刺激因子多糖玻璃体颗粒的PLGA微球,考察了微球的表面形态、粒径分布等,并且运用ELISA方法考察了微球的体外释放效果。结果：本方法制备的粒细胞-巨噬细胞集落刺激因子微球光滑圆整,粒径分布均匀,体外可以缓释达32天,累积释放率接近90％。结论：本方法制备的粒细胞-巨噬细胞集落刺激因子微球能有效地保护蛋白活性,同时实现长效缓释的目标,是一种可行的蛋白缓释方案。     

姜黄素壳聚糖微球的制备及其在体内外释放度的研究

目的:研究响应面法优化姜黄素壳聚糖微球制备的工艺参数,提高姜黄素的溶出度.方法:采用离子交联法制备姜黄素缓释微球,以微球的载药量和包封率为考察指标,采用星点设计考察配制壳聚糖的醋酸浓度、药物载体的比例以及交联剂浓度对微球制备工艺的影响,对结果进行二次多项式拟合,并根据最佳数学模型进行预测.结果:姜黄素壳聚糖微球最优制备工艺参数为:醋酸的浓度为1％,载体药物比例为0.83,交联剂的浓度为0.15％,载药量和包封率的预测值和理论值偏差分别为0.47％和3.2％.结论:响应面法优化姜黄素壳聚糖微球制剂处方具有很好的预测性,体内外药物释放度研究表明,最优条件下制备的微球可以在提高姜黄素溶出度的前提下缓慢释放达12h.     

壳聚糖-海藻酸钠包裹Hp全菌蛋白微球剂的研制及其表征分析

以壳聚糖、海藻酸钠为主要合成材料包裹幽门螺杆菌全菌超声蛋白抗原 ,制备新型Hp疫苗制剂。采用一定工艺 ,将海藻酸钠、壳聚糖以及Hp超声全菌抗原制备成W /O/W微球。通过扫描电镜、粒径分布仪等设备检测微球粒径大小 ;微球溶出度仪、Lowry法检测蛋白含量、高压液相色谱等检测微球的蛋白的包封率以及释放速率 ;12 5I标记后口服观测微球的定向靶向作用等。所制备微球形态规则 ,粒径均在 10 μm以内 ;包封率达到 4 1%左右 ;整个包封过程对蛋白没有任何降解作用 ;微球呈缓 快 缓释药模式 ,药物缓释时间可长达 72h ;微球在肠PP结分布明显高…     

一种白细胞介素-2缓释微球制备新方法及体外表征

目的：开发一种白细胞介素-2（m-2）长效缓释微球剂型。方法：采用S／O／W法制备了白介素-2因子多糖微粒的PLGA微球,考察了微球的表面形态、粒径分布等,并且运用ELISA方法考察了微球的体外释放效果。结果：本方法制备的白介素-2因子微球光滑圆整,粒径分布较均匀,体外缓释达32天,累积释放率近90％。结论：本方法制备的白介素-2因子微球,不仅具有有效地保护IL-2蛋白活性,同时实现长效缓释的目标,是一种可行的蛋白缓释方案。     

干扰素α缓释微球的制备及体外释放研究

目的:开发一种有效地长效缓释干扰素α微球制剂。方法:利用S/O/W乳剂-挥发法制备了包裹干扰素α多糖颗粒的PLAG微球,对其外观形态进行了考察,并用ELISA方法考察了微球体外释放效果。结果:制备的干扰素α微球圆整光滑,粒径均匀;经24天体外释放,累计释放率达到80%以上。结论:通过包封包裹干扰素α的多糖颗粒进PLGA微球,有效地保护了干扰素α在微球中的活性,实现了长效缓释,是一种可行的缓释方案。     

一种白细胞介素 -12 缓释微球制备及体外表征

目的:开发一种白细胞介素-12(IL-12)长效缓释微球剂型。方法:采用水包油-油包固(S/O/W)法制备了白介素-12因子多糖微粒的聚乳酸-聚羟基乙酸共聚物(PLGA-PLA)微球,研究了微球的表面形态和粒径大小,并且运用ELISA方法考察了微球的体外释放效果和免疫活性。结果:本方法制备的白介素-12因子微球光滑圆整,体外缓释达45天,累积释放率近90%。结论:本方法制备的白介素-12因子微球,不仅具有有效地保护IL-12蛋白活性,同时实现长效缓释的目标,是一种可行的IL-12缓释方案。     

重组人粒细胞集落刺激因子缓释微球的研究

目的：研究固体／油／水法制备重组人粒细胞集落刺激因子缓释微球,为开发其缓释剂型进行初步研究。方法：以聚乳酸．聚羟乙酸共聚物（PLGA）为载体材料：用固体／油／水法和水／油／水法制备载rhG-CSF缓释微球;考察粒径大小、外观、包封率等理化性质;用MieroBCA法考察微球的体外释药特性及影响因素;用SEC-HPLC和MTT比色法初步评价了微球制备工艺过程对rhG-CSF稳定性的影响。结果：两种方法制得的微球形态圆整、分散性良好,包封率均超过80％。固／油／水法制得的微球体外释放在2周内可超过90％,而水／油／水法制得的微球在相同的时间内仅释放30％。对于固／油／水法制备过程,SEC-HPLC法测定蛋白无明显聚集体出现,MTT法测定蛋白活性无明显损失。结论：实验证明了固／油／水法制备的PLGA微球可以实现2周以上的体外缓释。     

明胶微球在骨组织工程中的应用

骨组织工程通过联合利用种子细胞、生物活性因子和支架材料等要素来构建骨组织再生微环境,从而促进骨缺损的修复重建来诱导骨再生。明胶微球具有多孔性、生物降解性、生物相容性及生物安全性等优势,是一种极具应用潜能的骨修复材料。明胶微球用于体外培养种子细胞时可实现高效扩增。多官能团结构使其可作为促血管再生因子、促骨再生因子及抗感染因子等多种药物的递送载体,缓释药物的同时也可实现微球的多功能化。在构建明胶微球支架时与其他生物材料复合及血管化性能的赋予可提高支架材料的综合性能,但目前支架的设计还存在如何兼顾材料多孔结构和力学性能的问题。本文主要综述了明胶微球的常见制备技术及其近年来在骨组织工程中的应用,并对未来的发展前景进行展望。     

阿霉素载药微球在免疫缺陷大鼠肝脏原位肿瘤组织内缓释作用与长效抗肿瘤活性研究

目的:建立免疫缺陷大鼠肝脏原位肿瘤模型,以阿霉素为模型药物,在肿瘤组织注射吸附有阿霉素的载药微球,建立肿瘤组织内抗肿瘤药物缓释与长效作用的研究方法。方法:利用MHCC-97H高侵袭肝细胞癌细胞系在免疫缺陷裸鼠皮下成瘤后,解剖瘤块并切割,种植于免疫缺陷大鼠肝脏原位;进行开腹给药,将阿霉素载药微球精准注射进大鼠肝脏原位肿瘤组织中;收集大鼠血液、肿瘤组织标本等,检测药物在大鼠体内特别是肿瘤组织内的留存情况,最后进行PET/CT小动物活体成像,确定阿霉素载药微球在免疫缺陷大鼠肝脏原位肿瘤组织内缓释作用与长效抗肿瘤活性。结果:通过大鼠肝脏原位接种肝细胞癌瘤块可建立免疫缺陷大鼠肝脏原位肿瘤模型;使用阿霉素载药微球对病灶进行精准给药可实现阿霉素载药微球在体内的缓释作用;索拉非尼(Sorafenib)联用阿霉素载药微球可更显著地抑制大鼠肝脏原位肿瘤的生长。结论:建立了免疫缺陷大鼠肝脏原位肿瘤模型,建立了肿瘤组织内抗肿瘤药物缓释与长效作用的研究方法。     

葡萄糖基聚合物的酶催化合成及其在制备缓释微球中的应用

以脂肪酶Novozym-435催化葡萄糖和10-十一碳烯酸合成了6-O-(10-十一碳烯酸)-葡萄糖酯,在K2S2O8引发下合成了葡萄糖基聚合物.采用复凝聚法以葡萄糖基聚合物和海藻酸钠为基质材料,将非诺洛芬钙包裹制成缓释微球.通过L9(34)正交实验得出微球的最佳制备工艺条件,结果是葡萄糖基聚合物:海藻酸钠质量比=1:2,pH 3.0,搅拌速度400 r/min,反应成球温度45℃.在最佳工艺条件下制备的非诺洛芬钙缓释微球,粒径范围是10～20μm,平均药物包封率(73.74±3.12)%.同时,体外溶出试验表明,该微球具有较好的缓释作用.     

海藻酸钠壳聚糖微球作为药物载体的研究进展

海藻酸钠壳聚糖微球是具有生物粘附性且能结合和传递大分子药物的天然高分子材料,且在生物医学领域具有广阔应用前景的药物载体。它具有生物黏附性、生物相容性、生物可降解性、对人体无毒性且能够结合和传递大分子药物的天然高分子材料。海藻酸钠壳聚糖微球作为载药微球具有提高药物的生物利用度、延长药物的作用时间等优点。国内外近些年已将其应用于药剂学领域,以及将其作为药物载体经微球化与药物结合形成给药系统的研究也在逐步开展并取得了较多成果。本文主要阐述海藻酸钠壳聚糖微球的主要生物特性、作用特点及其在医学领域中应用的研究进展,并对其应用前景进行探讨。     

外用红色诺卡氏菌细胞壁骨架效力测试实验方法的研究

摸索改进外用红色诺卡氏菌（Nocardia rubra）细胞壁骨架的两种效力测试方法,即流式细胞术-荧光微球法、流式细胞术-免疫双标法（荧光微球+荧光抗体）,并与国家食品药品监督管理局原审批方法进行比较,经过统计学评估,评价两种方法的可行性。通过抽取小鼠免疫后获得的腹腔液注入到流式细胞仪,在发射光的荧光通路中,检测巨噬细胞的荧光强度,测定未吞噬荧光微球的巨噬细胞和吞噬荧光微球的巨噬细胞的比例,全部数据经统计学分析,按公式计算吞噬率及吞噬指数完成流式细胞术检测过程。分别采用荧光微球以及荧光微球+荧光抗体两种方式上机检测巨噬细胞吞噬结果。测得的结果与原检验方法——人工显微镜观察法的结果进行比较,确定评估方法的有效性和准确性。结果表明,显微镜人工计数法与流式细胞术-免疫双标法（荧光微球+荧光抗体）的3次实验结果与正常对照组比较,吞噬率明显升高（P<0.01）,吞噬指数明显增大（P<0.01）,有显著性差异,判定结果为阳性;3次流式细胞术-荧光微球法实验,结果不稳定。流式细胞术-免疫双标法（荧光微球+荧光抗体）由于加入了成熟小鼠巨噬细胞表面特异性标志物抗体F480荧光抗体,可有效标记小鼠巨噬细胞,加强了流式细胞仪收集巨噬细胞的准确性,两者结合应用更能准确反映供试品对小鼠巨噬细胞吞噬功能的作用。利用此方法检测外用红色诺卡氏菌细胞壁骨架增强免疫力的结果和药品原检验方法的统计学结果一致。该方法获取的巨噬细胞数量远多于原方法,加入的荧光微球及荧光抗体,能更准确反应供试品对小鼠巨噬细胞的吞噬作用。该方法灵敏性高、稳定性好,并且易操作,可作为原实验方法的改良参考。     

粒细胞-巨噬细胞集落刺激因子微球制剂治疗肿瘤的研究

目的：评价粒细胞－巨噬细胞集落刺激因子（GM—csF）微球剂型在肿瘤动物模型治疗作用。方法：建立肿瘤动物模型,微球剂型对该肿瘤模型治疗效果考察及毒性评价,同时与市售的注射水溶液剂型进行比较。结果：微球剂型和市售水溶液注射剂型同剂量对肿瘤模型治疗效果,微球剂型的效果明显好于市售的;同时微球剂型的毒性也小于市售的。结论：粒细胞－巨噬细胞集落刺激因子微球能提高GM—CSF治疗效果,同时降低毒性。     

尺寸均一的壳聚糖微球的制备及其作为胰岛素控释载体的研究

采用新型微孔膜乳化技术制备了载胰岛素的壳聚糖微球。研究表明,要制备粒径均一的壳聚糖微球,必须将亲水性膜修饰成疏水性;制得的微球粒径和所采用的膜孔径之间存在很好的线性关系,使得微球粒径可控;以胰岛素为模型药物,主要考察了交联剂用量和交联时间对微球表面形态、药物包埋率和微球体外释药特性的影响。结果表明当氨基与醛基的摩尔比为1∶0.7、交联时间为1h时,所得载药微球的包埋率最高,随着戊二醛用量的增加和交联时间的延长,药物体外释放速率减慢。     

In vivo release kinetics of octreotide acetate from experimental polymeric microsphere formulations using oil/water and oil/oil processes

The purpose of the present study was to characterize the in vivo release kinetics of octreotide acetate from microsphere formulations designed to minimize peptide acylation and improve drug stability. Microspheres were prepared by a conventional oil/wate (o/w) method or an experimental oil/oil (o/o) dispersion technique. The dosage forms were administered subcutaneously to a rat animal model, and serum samples were analyzed by radioimmunoassay over a 2-month period. An averaged kinetic profile from each treatment group, as a result, was treated with fractional differential equations. The results indicated that poly(l-lactide) microspheres prepared by the o/o dispersion technique provided lower area under the curve (AUC) values during the initial diffusion-controlled release phase, 7.79 ng×d/mL, versus 75.8 ng/sxd/mL for the o/w batch. During the subsequent erosion-controlled release phase, on the other hand, the o/o technique yielded higher AUC values, 123 ng×d/mL, versus 42.2 ng×d/mL for the o/w batch. The differences observed between the 2 techniques were attributed to the site of drug incorporation during the manufacturing process, given that microspheres contain both porous hydrophilic channels and dense hydrophobic matrix regions. An o/o dispersion technique was therefore expected to produce microspheres with lower incorporation in the aqueous channels, which are responsible for diffusion-mediated drug release.     

影响PLGA微球包封率和粒径相关因素研究进展

聚乳酸乙醇酸共聚物(PLGA)是一种可生物降解的高分子聚合物,具有良好的生物相容性,其降解产物为乳酸和乙醇酸,是机体正常代谢的中间产物,最终可分解为二氧化碳和水,并分别经肺和肾脏排出体外,对人体不产生危害,所以PLGA在微球制剂的制备中常作为首选载体。近年来PLGA微球制剂在医药领域有着飞跃发展,尤其是在抗肿瘤、免疫疫苗、蛋白给药、基因治疗、诊断试剂和细胞支架等方面显现出很大优势。而且已有许多PLGA微球获得美国FDA批准上市,临床应用也有令人满意的效果,未见报道有严重的不良反应。但现阶段国内生产的PLGA缓释微球的质量还有很多不足之处如微球粒径偏大、包封率和载药量偏低、突释过大等,有待进一步提高和改进。本文将综述在制备包裹水溶性药物的PLGA微球过程中相关因素如药物本身理化性质、制备方法、PLGA结构特点、有机溶剂等对微球粒径、包封率的影响,以期为提高以PLGA为药物载体的药效奠定良好的理论基础。     

Spray-dried poly(D,L-lactide) microspheres containing carboplatin for veterinary use: In vitro and in vivo studies

The aim of this study was the development of a veterinary dosage form constituted by injectable biodegradable microspheres designed for the subcutaneous release of carboplatin, a chemotherapeutic drug. Poly(D,L-lactide) (PDLLA) microspheres were prepared by an emulsification/spray-drying method, using the drug-to-polymer weight ratios 1∶9 and 1∶5; blank microspheres (1% w/v) were prepared as a comparison. Microparticles were characterized in terms of morphology, encapsulation efficiency, and in vitro drug release behavior. In vivo tests were conducted on rats by subcutaneous injection of microsphere aqueous suspensions. Levels of carboplatin were evaluated both in the skin and in serum. The microparticles obtained had a spherical shape; particle size ranged from 5 to 7 μm, dependent on drug loading. Microspheres were able to control the in vitro release of the drug: approximately 90% to 100% of the carboplatin was released over 30 days. In vivo results showed that the microspheres were able to release high drug amounts locally, and sustained serum levels of drug were also achieved. Based on these results, carboplatin-loaded PDLLA microspheres may be useful for local delivery of the antineoplastic drug to the tumor, avoiding tumor recurrence in small animals, and may decrease the formation of distant metastases. Published: September 20, 2005     

Release of indomethacin from pH-sensitive pullulan acetate microsphere

We studied the pH-sensitive indomethacin (IND) delivery system using pullulan. Hydrophobic pullulan acetate was prepared by chemical modification of hydrophilic pullulan and pullulan acetate microsphere was made by a solvent evaporation method. The size of microspheres was below 5 μm, and the drug loading efficiencies of microspheres were approximately 78 and 65% at the initial amount of drug 40 and 80 mg, respectively. The microsphere showed pH-sensitive swelling behavior in PBS buffer. After 15 hrs, the swelling of the microsphere at pH 7.4 was approximately 20 times greater than that at pH1.2. The pH of the medium significantly influenced on thein vitro release rate. The released amount of drug at pH 7.2 was approximately 90 times greater than that at pH 1.2. The shape of microspheres at pH 1.2 were maintained sphere forms, but at pH 7.4 were disintegrated. The pH-sensitive IND release pattern was due both to the pH-sensitive diffusion of IND from the microspheres and to the release of the drug from the surface which underwent disintegration after swelling, due to the chemical composition of the microspheres and the pH of the release media.     

Selective Interactions of Zein Microspheres with Different Class of Drugs: An In Vitro and In Silico Analysis

In this study, we have evaluated the interactions of zein microspheres with different class of drugs (hydrophobic, hydrophilic, and amphiphilic) using in vitro and in silico analysis. Zein microspheres loaded with aceclofenac, metformin, and promethazine has been developed by solvent evaporation technique and analyzed for its compatibility. The physical characterization depicted the proper encapsulation of hydrophobic drug in the microspheres. The in vitro release study revealed the sustaining ability of the microspheres in the following order: hydrophobic > hydrophilic > amphiphilic. In silico analysis also confirmed the better binding affinity and greater interactions of hydrophobic drug with zein. The above results revealed that zein is more suitable for hydrophobic drugs in the development of sustained drug delivery systems using solvent evaporation technique. The study therefore envisages a scope for identifying the most suitable polymer for a sustained drug delivery system in accordance with the nature of the drug.KEY WORDS: hydrophilic drugs, hydrophobic drugs, in silico analysis, protein-drug interactions, solvent evaporation, zein microspheres     

Pectin microspheres for oral colon delivery: Preparation using spray drying method and<Emphasis Type="Italic">in vitro</Emphasis> release of indomethacin

Drug delivery systems that are based on pectin have been studied for colon specific delivery using the specific activity of colon microflora. The aim of this study was to design a novel method of manufacturing pectin microspheres without oils and surfactants and to investigate the potential use of the pectin microsphere as an oral colon-specific drug carrier. The pectin microspheres were successfully formed using the spray drying method and crosslinking with calcium chloride. From the crosslinked pectin microspheres, indomethancin (IND) release was more supressed than its release from non-crosslinked microspheres. In a low pH (pH 1.4) environment, the pectin microspheres released IND at an amount of about 18±2% of the total loaded weight for 24h while the release rate of IND was stimulated at neutral pH (pH 7.4). IND release from the pectin microspheres was increased by the addition of pectinase. The results clearly demonstrate that the pectin microspheres that were prepared by the spray drying and crosslinking methods are potential carriers for colon-specific drug deliveries.