胶原-壳聚糖载硫酸长春新碱微球缓释药膜的研究

目的本研究制备载硫酸长春新碱(vincristinesulfate,VCR)微球的胶原-壳聚糖缓释药膜。并考察加入壳聚糖对药膜性质的影响。选定适当的胶原壳聚糖比例制备药膜。方法采用W/O/O溶剂挥发法制备VCR的聚乳酸-羟基乙酸(poly(lactic-co-glycolicacid),PLGA)微球,并对微球性质表征,采用二次冻干法制备载VCR微球的胶原-壳聚糖药膜,对药膜的表面形态、降解性质、热力学性质及释放性质进行表征,并与释放2周后的药膜进行比较。采用高效液相法分析药物含量。结果VCR制成PLGA微球后再制备成药膜,可达到双重缓释的作用,明显减少药物突释,并延缓药物释放。添加了壳聚糖的药膜降解速度明显小于单纯的胶原药膜。在体外释放实验中,微球突释为(27.2±1.2)%,而胶原药膜的突释为(20.4±1.9)%,胶原与壳聚糖比例为9∶1、4∶1、3∶2的药膜突释分别为(20.2±2.1)%、(18.0±1.1)%和(16.3±1.8)%。结论胶原壳聚糖载VCR的缓释药膜能不同程度减少药物的突释,使药物释放更加平稳缓慢,优于单纯的胶原药膜。     

硫酸长春新碱缓释药膜的制备及稳定性初步研究

目的制备出载硫酸长春新碱微球的胶原-壳聚糖缓释药膜,并考察该制剂的稳定性。方法采用W/O/O溶剂挥发法制备载硫酸长春新碱的聚乳酸/聚羟基乙酸共聚物(PLGA)微球,后把微球与壳聚糖、胶原溶液共混及二次冻干,制备出载硫酸长春新碱微球的胶原-壳聚糖药膜。对微球和药膜表面形态进行了电镜观察,测定了微球和药膜的包封率、载药量及药物释放,药物含量采用高效液相法检测。此外,还初步考察了缓释药膜的稳定性。结果制备的微球包封率达到79.0%±1.0%,微球药物的突释为27.2%±1.2%,制备成药膜后降低到18.0%±1.1%,采用该工艺流程制备出来的缓释药膜,药物突释明显减少。稳定性实验显示,该药膜在40℃条件下放置3个月药物含量下降到97.9%±0.1%,而高湿度或光照环境下放置10 d药物含量下降到91.4%±0.3%和91.2%±0.4%。结论药物包囊制成微球后与胶原、壳聚糖共混制备出的缓释药膜具有较好的释放特性和稳定性,有望成为一种实用的新型缓释抗肿瘤制剂。     

强的松龙纳米微球缓释膜制备及缓释特性

背景:近年来将强的松龙应用于促进周围神经损伤后功能恢复取得了良好效果,但因半衰期短、局部应用血药浓度不稳定及较大的不良反应限制了其临床应用。目的:制备强的松龙纳米微球缓释膜并对其药物缓释特性进行检测。方法:采用反胶束乳化溶剂挥发法制备强的松龙纳米微球,对载药纳米微球的形态、粒径、载药量、包封率和体外释药行为等性质进行研究;同时将纳米微球与胶原、壳聚糖、大豆卵磷脂等膜材相结合,制得复合药膜,考察复合药膜的形貌、膜中材料的相互作用及药膜的体外释药行为。结果与结论:强的松龙纳米微球具有良好的微观结构,药物均匀分布于纳米微球中,纳米微球粒径均一,表面光滑,平均粒径500 nm,包封率达90%以上,体外缓释实验药物释放良好,存在一定的药物突释现象。观察球膜结合方法制得的复合膜,可见纳米微球均匀分散于复合膜中,复合膜微观结构良好,体外缓释实验见复合膜药物释放更加稳定,无明显药物突释现象出现,显示了良好的药物释放效果。表明通过反胶束乳化溶剂挥发法和球膜结合方法制备出的强的松龙缓释膜剂具有良好的药物缓释特性。     

载表皮生长因子/壳聚糖纳米粒纤维蛋白胶胶联羊膜的制备及体外释药评价

背景：纤维蛋白胶胶联羊膜作为一种无需缝合生物移植材料还无法有效地在局部长时间缓释药物,特别是对于一些不稳定的生物活性蛋白药物。 目的：构建新型的能有效缓释蛋白药物的载表皮生长因子壳聚糖纳米粒纤维蛋白胶羊膜复合体。 方法：制备表皮生长因子/壳聚糖载药纳米粒并考察其表征,然后将载药纳米粒掺入纤维蛋白胶,再将载纳米粒的纤维蛋白胶和羊膜胶联黏合,制备出负载表皮生长因子/壳聚糖纳米粒纤维蛋白胶胶联羊膜,并进行形态学和体外释药观察,检测释放出的表皮生长因子生物活性。 结果与结论：表皮生长因子/壳聚糖纳米粒的粒径为(275.7±6.8) nm,Zeta电位为(32.7±0.6) mV,包封率为(67.03±1.22)%,多分散指数为0.23±0.04,形态圆形均一,载纳米粒纤维蛋白胶能够很好地与羊膜胶联黏合,表面呈网状结构,纳米粒充斥其中。载表皮生长因子/壳聚糖纳米粒纤维蛋白胶胶联羊膜体外释药可达14 d,释放的表皮生长因子生物活性可保持7 d以上。说明制备的载重组人表皮生长因子/壳聚糖纳米粒纤维蛋白胶胶联羊膜作为一种无缝合生物移植材料可在局部缓慢释放表皮生长因子。     

京尼平交联音猬因子复合纤维蛋白支架修复大鼠脊髓损伤

背景：组织工程支架移植是修复脊髓损伤最有应用前景的治疗手段之一,通过组织工程支架募集内源性神经干细胞并促进其分化为神经细胞,进而修复脊髓损伤。目的：观察京尼平交联的音猬因子复合纤维蛋白支架移植到大鼠脊髓损伤处的修复作用,探讨其作用机制。方法：分别制备纤维蛋白胶、音猬因子复合纤维蛋白支架、京尼平交联音猬因子复合纤维蛋白支架,检测京尼平交联音猬因子复合纤维蛋白支架的体外降解率与缓释性能。将120只雌性SD大鼠随机分为4组,每组30只,A组T10-T11脊髓损伤部位不植入任何材料,B组T10-T11脊髓损伤部位植入纤维蛋白胶,C组T10-T11脊髓损伤部位植入音猬因子复合纤维蛋白支架,D组T10-T11脊髓损伤部位植入京尼平交联音猬因子复合纤维蛋白支架,术后每周对大鼠进行运动功能BBB评分,术后12周取脊髓损伤处及周围脊髓组织,进行组织形态与WesternBlot检测。结果与结论：(1)音猬因子复合纤维蛋白支架14 d基本完全降解,京尼平交联的纤维蛋白支架14 d的降解率不超过20%;音猬因子复合纤维蛋白支架7 d基本完全释放了音猬因子;京尼平交联音猬因子复合纤维蛋白支架在1-3 d爆发释放...     

植入型表阿霉素缓释药膜的制备及体内抑瘤活性

制备用于实体肿瘤局部治疗的植入型表阿霉素缓释药膜.采用复乳.溶剂挥发法制备聚乳酸载表阿霉素缓释微球,用交联复合法制备含载药微球的植入型胶原药膜;用扫描、透射电镜、共聚焦及粒度仪等考察微球和药膜的形貌、结构、粒径及体外释放;用H22肝癌荷瘤动物模型评价其体内抑瘤效果.结果:载药微球粒径分布均匀,外观圆整,平均粒径为5.8μm;微球的载药量4.39%,包裹率为37.2%;10h内载药微球在模拟体液中的累积释放率为35%;腹腔注射载药微球与瘤体局部植入胶原药膜对H22肝癌均有明显的抑瘤效果;微球注射与药膜植入两种不同给药方式对H22肝癌抑瘤效果也存在显著性差异(P<0.05).植入型载表阿霉素缓释胶原膜具有良好的药物局部缓释特性,在肿瘤的术后局部治疗方面具有良好的临床应用前景.     

乳酸-羟基乙酸共聚物缓控释微球的制备及突释成因与影响因素

背景：乳酸-羟基乙酸共聚物是一种生物可降解高分子材料,以乳酸-羟基乙酸共聚物为原料制备的载药微球和纳米粒既可提高药物的稳定性,又能实现缓释、控释和靶向释放。 目的：分析乳酸-羟基乙酸共聚物缓控释微球的制备方法以及突释的成因、影响因素和改进方法。 方法：应用计算机检索1990/2010中国期刊全文数据库和PubMed数据库与乳酸-羟基乙酸共聚物缓控释微球的制备及突释联系紧密的文章。 结果与结论：目前乳酸-羟基乙酸共聚物缓释微球制备方法主要有单凝聚法、乳化-固化法、喷雾干燥法。造成其突释的原因首先是药物分子和聚合物分子之间的相互作用太弱,导致药物很容易从微球进入释放递质中,其次是在微球释放初期,药物从微球中的孔洞和缝隙中释放出来导致突释。影响突释程度的具体因素有乳酸-羟基乙酸共聚物的相对分子质量、浓度、微球载药量、主药理化性质、微球制备方法及制备参数等。虽然国内外对突释机制以及控制突释措施的研究都还处于初步阶段,通过对各影响因素加以适当优化与控制,可在一定程度上减少微球的突释率,突释问题应该能够得到解决和控制。     

胶原/纤维蛋白胶/载BSA微球复合支架的制备及体外性能研究

为改善组织工程支架材料内部营养供应不足及分布不均的问题,制备胶原/纤维蛋白胶/载BSA微球复合支架（S_CFM）并研究其理化性质及其BSA释放行为。本研究中采用戊二醛交联并冷冻干燥制备多孔胶原海绵支架,纤维蛋白与载BSA的PLGA微球混合后加入凝血酶,注入胶原膜中制备复合支架,研究支架形态学、孔隙率、机械强度等理化性质;通过BCA试剂盒法测定支架内部不同部位BSA含量及释放行为,圆二色谱法检测BSA的二级结构。扫描电镜结果显示制备的胶原支架孔径分布均匀,孔径平均(130±45) μm;相对于胶原/纤维蛋白胶/BSA支架（S_CFB）,在体外释放48 h时累积释放率为75.20%±2.74 %,随后BSA即不再显著增加;而支架S_CFM中的BSA释放时间延长,持续释放144 h,测定其累积释放量为72.36%±3.48 %;测定支架S_CFM代表性的3个部位的BSA含量均匀,在释放96 h内均高于支架外BSA含量,且圆二色谱结果表明BSA二级结构未见异常。支架S_CFM可长时间维持支架内部BSA含量,且持续均匀释放,是理想的组织工程支架材料。     

载ADM-PLGA纳米微球的ADM-PLGA-NHAC制备及其对人骨肉瘤MG63细胞的抑制作用

目的　研制载阿霉素(ADM)的聚乳酸-羟基乙酸共聚物(PLGA)纳米微球的纳米羟基磷灰石/胶原复合支架（ADM-PLGA-NHAC）,研究其性质及体外释药特点,探讨其体外抑制人骨肉瘤MG63细胞的作用,为骨肉瘤的治疗提供新策略。 方法　以纳米羟基磷灰石及胶原为原料制备纳米羟基磷灰石/胶原支架并在其中加载ADM-PLGA纳米微球, 通过扫描电子显微镜、体外释放行为等手段评价载药支架材料的性能。以CCK8法、活-死染色评价该复合支架的浸提液在体外对人骨肉瘤MG63细胞株的抗肿瘤活性。 结果　复合支架的孔径多在100~200 μm,孔隙率约为82%,微球与支架间结合较为紧密。复合支架具有良好的缓释特性,28 d内能持续缓慢释放阿霉素。复合支架的浸提液对骨肉瘤MG63细胞生长有明显的抑制作用。 结论　制备的ADM-PLGA-NHAC复合支架具有良好的药物缓释特性及抗肿瘤效应,是一种具有良好应用前景的抗骨肉瘤骨修复材料。     

京尼平交联3D打印胶原/壳聚糖支架的表征北大核心

背景:胶原/壳聚糖支架需交联才能达到相应力学性能,有研究表示调节交联剂浓度可以在一定范围内调控支架的理化性能。目的:探究京尼平浓度对胶原/壳聚糖支架理化性能的影响,制备理化性能可调节的组织工程支架。方法:将胶原和壳聚糖粉末分别溶于弱酸后混合均匀,作为打印墨水,利用生物3D打印机低温打印胶原支架与胶原/壳聚糖支架,经冻干、中和处理后分别以1,3,5 mmol/L的京尼平进行交联。检测各组支架的表观结构稳定性、抗拉能力、溶胀性能、降解性能与生物相容性。结果与结论:①将支架在PBS中浸泡3 d后,对比未交联的冻干支架,交联后胶原支架表面维持规则的孔结构,但是支架出现明显变形;交联后胶原/壳聚糖支架表面结构规则,仅1 mmol/L京尼平交联的胶原/壳聚糖支架存在轻微变形。②随着京尼平浓度的增加,各组支架的力学性能增加,并且对应交联浓度下的胶原/壳聚糖支架力学性能好于胶原支架。③随着京尼平浓度的增加,胶原支架的溶胀率下降,胶原/壳聚糖支架的溶胀率无明显变化。④浸泡于胶原酶溶液中后,不同浓度京尼平交联的胶原支架在1 h内被完全降解,胶原/壳聚糖支架的降解速率随京尼平浓度的增加而降低,均呈现先快速后平缓的趋势。⑤将骨髓间充质干细胞接种于各组交联支架3 d后,1,3 mmol/L京尼平交联的胶原/壳聚糖支架(或胶原支架)上的细胞数量明显多于5 mmol/L京尼平交联的胶原/壳聚糖支架(P<0.05)。⑥结果表明,京尼平可在一定范围调节胶原/壳聚糖支架理化性能,其中3 mmol/L京尼平交联的胶原/壳聚糖支架具有较好的力学性能、抗酶解能力与生物相容性。     

The study of improved controlled release of vincristine sulfate from collagen-chitosan complex film

A water-in-oil-in-oil double-emulsion solvent/evaporation method was used to prepare vincristine sulfate (VCR) loaded poly(lactide-co-glycolide) microspheres, and then VCR microspheres were mixed with collagen and (or) chitosan swelling solution and lyophilized to form polymeric films. The films were cross-linked by 0.3% glutaraldehyde (GA). Encapsulation efficiency and release kinetics of VCR microspheres were determined, as well as release kinetics and in vitro degradation of the film. The rate of VCR release from the film submerged in PBS (pH 6.8) and the content were measured by high-performance liquid chromatography (HPLC). The physichemical properties of the film, such as surface morphology, mechanical function, and differential scanning calorimetry, were also measured. VCR was released from the film in a prolonged period and the initial burst release of the film was less significant. In the degradation experiment, the film containing chitosan degraded more slowly than that without chitosan. The films comprising collagen and chitosan could achieve the release kinectics of a relatively constant release. It has a promising future.     

The controlled release study of Vincristine Sulfate

We prepared microspheres of Vincristine Sulfate (VCR) through drying-from-oil method, then mixed the microspheres into 0.7% collagen swelling solution to prepare emulsion, spread the emulsion on plate to form film by frozen-dry method. The film was cross-linked and sterilized, then planted into the site of tumor and expected to release at steady speed. We measured the release of VCR in vivo and in vitro by HPLC. The results demonstrated that VCR controlled release films release at approximate steady speed in 15 days.     

组织诱导性神经导管的制备及性能评价

本研究的目的是构建一种新型的组织诱导性神经导管并评价其生物学性能。壳聚糖包被中药川芎嗪制备微球,利用体外缓释方法检测壳聚糖/川芎嗪微球的缓释效果;壳聚糖/川芎嗪微球与胶原蛋白复合构建组织诱导性神经导管,2%京尼平交联导管;万能材料试验机评价交联前后神经导管的力学特征;体外降解试验分析交联前后神经导管的降解性能;应用织物手感评价仪检测神经导管的柔韧性;扫描电镜(SEM)观察神经导管交联前后空间结构及微球的分布;光学显微镜(LMS)和免疫荧光方法观察并评价壳聚糖微球/胶原蛋白神经导管与大鼠间充质干细胞(MSCs)共培养对MSCs向神经细胞定向分化的影响;SEM和细胞免疫荧光方法分别评价神经导管与MSCs的复合情况及对细胞定向分化的影响。结果显示:壳聚糖微球具有良好的缓释效果;交联前后神经导管的最大载荷和断裂载荷分别为(0.23±0.09)N、(0.76±0.15)N和(0.20±0.12)N、(0.69±0.17)N,两者相比具有统计学意义(P<0.05);体外降解实验表明,交联前后导管的平均失重率分别为(58.62±7.59)mg和(9.23±2.47)mg,两者相比具有统计学意义(P<0.01);干湿态神经导管的平均线性度分别为(0.597±0.012)LC和(0.333±0.015)LC,两者相比差异具有统计学意义(P<0.01),湿态神经导管的柔韧性较干态好;交联后神经导管中胶原蛋白排列紧密,微球均匀分布于胶原支架材料;神经导管与MSCs共培养后,微球缓释的川芎嗪能促进MSCs表达神经细胞相关标志分子NSE和MAP2;神经导管与MSCs复合培养,通过缓释的川芎嗪促进MSCs增殖和NSE的表达。构建的组织工程化神经导管具有良好的组织相容性和组织诱导性功能。     

Controlled release of bioactive TGF-beta 1 from microspheres embedded within biodegradable hydrogels

Transforming growth factor-beta1 (TGF-beta1) is of great relevance to cartilage development and regeneration. A delivery system for controlled release of growth factors such as TGF-beta1 may be therapeutic for cartilage repair. We have encapsulated TGF-beta1 into poly(DL-lactide-co-glycolide) (PLGA) microspheres, and subsequently incorporated the microspheres into biodegradable hydrogels. The hydrogels are poly(ethylene glycol) based, and the degradation rate of the hydrogels is controlled by the non-toxic cross-linking reagent, genipin. Release kinetics of TGF-beta1 were assessed using ELISA and the bioactivity of the released TGF-beta1 was evaluated using a mink lung cell growth inhibition assay. The controlled release of TGF-beta1 encapsulated within microspheres embedded in scaffolds is better controlled when compared to delivery from microspheres alone. ELISA results indicated that TGF-beta1 was released over 21 days from the delivery system, and the burst release was decreased when the microspheres were embedded in the hydrogels. The concentration of TGF-beta1 released from the gels can be controlled by both the mass of microspheres embedded in the gel, and by the concentration of genipin. Additionally, the scaffold permits containment and conformation of the spheres to the defect shape. Based on these in vitro observations, we predict that we can develop a microsphere-loaded hydrogel for controlled release of TGF-beta1 to a cartilage wound site.     

Effects of the controlled-released TGF-beta 1 from chitosan microspheres on chondrocytes cultured in a collagen/chitosan/glycosaminoglycan scaffold

The objectives of this study were (1) to develop a three-dimensional collagen/chitosan/glycosaminoglycan (GAG) scaffold in combination with transforming growth factor-beta1 (TGF-beta 1)-loaded chitosan microspheres, and (2) to evaluate the effect of released TGF-beta 1 on the chondrogenic potential of rabbit chondrocytes in such scaffolds. TGF-beta 1 was loaded into chitosan microspheres using an emulsion-crosslinking method. The controlled release of TGF-beta 1, as measured by enzyme-linked immunosorbent assay (ELISA), was monitored for 7 days. The porous scaffolds containing collagen and chitosan were fabricated by using a freeze drying technique and crosslinked using 1-ethyl-3-(3-dimethyl aminopropyl)carbodiimide (EDC) in the presence of chondroitin sulfate (CS), as a GAG component. The TGF-beta 1 microspheres were encapsulated into the scaffold at a concentration of 10 ng TGF-beta 1/scaffold and then chondrocytes were seeded in the scaffold and incubated in vitro for 3 weeks. Both proliferation rate and glycosaminoglycan (GAG) production were significantly higher in the TGF-beta 1 microsphere-incorporated scaffolds than in the control scaffolds without microspheres. Extracellular matrix staining by Safranin O and immunohistochemistry for type II collagen were elevated in the scaffold with TGF-beta 1 microspheres. These results suggest that TGF-beta 1 microspheres when incorporated into a scaffold have the potential to enhance cartilage formation.     

紫杉醇聚己内酯／泊洛沙姆188共混载药微球及其抗肿瘤活性

目的本研究首次尝试利用聚己内酯（PCL）与亲水性添加剂泊洛沙姆188（Pluronic F68,F68）共混物作为载体材料与抗癌药物紫杉醇组成微球缓释载药系统。方法采用乳化,溶剂挥发法制备紫杉醇PCL/F68共混微球;考察紫杉醇PCL／F68共混微球的表面形态、平均粒径、包埋率及体外释放性能：利用DSC法分析紫杉醇在PCL／F68共混徽球中的分散状态;考察紫杉醇PCL/F68共混微球在小鼠肝癌H22腹水瘤模型中的抗肿瘤活性。结果表明载体材料中的亲水性添加剂F68可在微球表面形成孔状结构,F68的加入提高了紫杉醇从PCL／F68共混载药微球的释放并获得了接近恒定的释放性能;在小鼠肝癌H22腹水瘤模型中。紫杉醇PCL／F68共混载药微球对肿瘤生长具有抑制作用,荷瘤小鼠生存期明显延长。结论以PCL/F68共混物为载体制备的紫杉醇控释微球具有较高的释放能力和明显的控释效果．     

Design and delivery of silver sulfadiazine from alginate microspheres-impregnated collagen scaffold

A reconstituted collagen scaffold impregnated with silver sulfadiazine (SSD) loaded alginate microspheres, capable of delivering the drug in a controlled manner has been developed. SSD-loaded alginate microspheres were prepared by modified water-in-oil emulsion technique through interfacial ionic gelation of alginate using CaCl2. The SSD-loaded microspheres were impregnated in pepsin-solubilized collagen, in situ, while inducing fibrillation and cast as thin scaffold. Morphological features of microspheres and microsphere-impregnated collagen were analyzed through SEM. Distribution homogeneity of impregnated microspheres, their in vitro behavior in (Dulbecco's modified minimal essential media) DMEM, and antibacterial efficiency against ATCC pathogens were determined. Initial drug load of 20% (w/w) with respect to alginate and 40% (v/v) of 2% alginate with respect to oil phase were found to produce microspheres of optimum drug entrapment (3%) and required size range (300-370 microm). In vitro drug release studies from the scaffold showed an initial burst release of 47.5% and a controlled release for 72 h with equilibrium concentration of 68.8%. SSD-loaded microspheres exhibited minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) levels of 32 and 40.2 microg/mL to both K. pneumoniae and E. coli respectively. P. aeruginosa showed MIC and MBC levels of 44.8 and 51.2 microg/mL respectively, while Staphylococcus aureus exhibited MIC and MBC at the same concentration range (57.6 microg/mL). The collagen-based scaffold impregnated with SSD-loaded alginate microspheres can deliver SSD in a controlled fashion, can control infection for extended time period with lesser dressing frequencies, and will enable easier assessment of wound.     

异硫氰酸荧光素标记的神经生长因子缓释微球的制备及评价

目的 探讨异硫氰酸荧光素(FITC)标记的神经生长因子缓释微球的制备,并对其进行体内外评价.方法 采用水-油-水的双乳化技术制备FITC标记的神经生长因子缓释微球.利用扫描电镜和荧光显微镜对其形态特征进行观察,并对其体内外释放情况进行研究.结果 制备的FITC标记的神经生长因子缓释微球包封率和载药量分别为(97.9±8.9)%和(4.90±0.56)%.扫描电镜结果显示所制备的微球呈圆形、形态规整、粒径分布较均匀.荧光显微镜结果显示所包载的蛋白类药物在微球内旱随机分布.缓释微球体外持续释放5周后,有73%的蛋白释放出来;荧光示踪显示在体内能够持续释放达5周以上.结论 采用水-油-水的双乳化技术制备的缓释微球可以将生物大分子药物如神经生长因子成功运载到脑内.