Preparation and embedding–releasing behavior of polyelectrolyte microcapsule

以高压静电法制备的壳聚糖微球为模板, 与海藻酸钠层层自组装制备多层聚电解质膜, 再以乙酸溶出壳聚糖微球制备出微胶囊. 调节乙酸的浓度及溶出时间以控制核内壳聚糖的残留量, 从而诱导负电性荧光素钠的沉积. 微胶囊内部荧光素钠的浓度随着包埋时间的增加而呈线性地提高, 当荧光素钠溶液的浓度为2 mg/l时其最终包埋的浓度达到10.2 mg/l. 这种聚电解质微囊对于小分子负电荷荧光素钠的释放行为主要受其囊壁和内部模板结构的影响, 盐离子浓度对荧光素钠释放行为的影响较小.     

作为药物载体的壳聚糖/氧化石墨烯中空微胶囊的制备

采用层层自组装法,以氧化硅微球为模板制备了壳聚糖(CS)/氧化石墨烯(GO)微球,去核后成功地制备了CS/GO中空微胶囊。研究了组装次数、壳聚糖浓度和交联剂京尼平对微球及中空微胶囊形貌的影响,并以布洛芬为药物模型研究了CS/GO中空微胶囊的载药性能及药物缓释性能。实验结果表明,CS/GO中空微胶囊具有完整的中空结构,粒径在760nm左右。增加包裹层数和提高包裹溶液中的壳聚糖浓度都可以增加囊壁的厚度。经交联处理后,CS/GO微胶囊的囊壁更加致密和完整,其对布洛芬的载药率从19%提高至72%,释药时间从10h延长至60h。     

壳聚糖/海藻酸盐微胶囊膜的物质扩散性能研究

针对微囊化细胞三维培养研究背景,以壳聚糖、海藻酸钠为微载体制备材料,采用脉冲电场液滴工艺制备海藻酸钙微球,使之与壳聚糖溶液通过聚电解质络合反应生成选择透过性微囊膜.以传统细胞培养的重要碳源葡萄糖与柠檬酸、氮源L-谷氨酸为小分子模型,以聚乙二醇为测定微囊膜截留相对分子质量的模型分子,开展微胶囊传递性能研究.结果表明,葡萄糖、柠檬酸和L-谷氨酸可以自由透过微囊膜扩散,并且柠檬酸和L-谷氨酸能通过竞争螯合Ca2+引起微囊凝胶结构解聚;采用20 mg/mL海藻酸钠溶液与5万相对分子质量、2 mg/mL壳聚糖溶液制备微胶囊,囊膜的截留相对分子质量为1 500.     

茶多酚/壳聚糖/海藻酸钠纳米微球的制备

目的探讨各因素对制备茶多酚/壳聚糖/海藻酸钠纳米微球载药率、包埋率的影响,研究纳米微球体外释放行为,为后期缓释抗菌膜的制备提供基础。方法采用单因素实验、正交实验考察海藻酸钠溶液浓度、壳聚糖溶液浓度、CaCl_2溶液浓度、茶多酚溶液浓度对纳米微粒载药率、包封率的影响,并考察其体外释放率。结果当海藻酸钠溶液、壳聚糖溶液、CaCl_2溶液、茶多酚溶液的质量浓度分别为15,10,15,0.8 mg/m L时,该工艺条件下制备的纳米微粒载药率为22.71%,包封率为61.38%,且粒径集中在500 nm左右,有较好的缓释效果。结论所得的最佳工艺制备条件为后期做缓释抗菌膜打下良好基础。     

广藿香油缓释微胶囊的制备及其性能分析

以广藿香油为芯材,壳聚糖和阿拉伯胶为壁材,采用复凝聚法对广藿香油进行包埋,制备广藿香油微胶囊。利用扫描电子显微镜、激光粒度仪、红外光谱和紫外光谱等分析方法研究各因素对微胶囊形成的影响。确定制备广藿香油微胶囊的最佳条件:采用中低粘度的壳聚糖,壳聚糖浓度为0.5%,阿拉伯胶浓度为4%,芯壁比为1∶2,复凝聚pH值为4.5,搅拌转速为2000r/min。红外光谱分析表明广藿香油包埋成功,其载药量和包封率分别为20.75%和67.2%。微胶囊缓释性能测试结果表明微胶囊具有良好的缓释效果,在25℃条件下,微胶囊释放150h后,累计释放率为33%,即微胶囊保留率为67%。     

纳米结构的空腔二氧化硅微球的制备与缓释行为

以单分散聚苯乙烯(PS)微球作为胶体模板,采用层层静电自组装技术,交替组装聚电解质聚二烯丙基二甲基氯化铵[poly(diallyldimethylammonium chloride),PDDA]和二氧化硅纳米颗粒(10和20nm),得到核壳型聚苯乙烯/聚电解质/二氧化硅复合微球,高温煅烧除去模板PS和聚电解质,制得空腔二氧化硅微球.TEM观察的结果显示空腔二氧化硅微球呈单分散性且内部空腔呈球形;XRD图谱显示组装的二氧化硅颗粒热处理后晶化的程度很小,仍基本保持着无定形状态;N₂等温吸附-脱附实验测得用10和20nm的二氧化硅组装成的空腔二氧化硅微球的平均孔径和比表面积分别为11nm、282.71m²·g^-1和15nm、158.17m²·g^-1. 染料的装载和释放实验分别验证了空腔二氧化硅微球的腔壁具有可渗透性和缓释性.     

载γ-球蛋白微包纳载体的制备与性能

为了结合不同载体的特点从而实现更佳的性能,载体的集成化研究已日益成为研究者关注的热点。为了延长微胶囊的释放时间,构筑了新型的微包纳载体形式并用于大分子药物γ-球蛋白的包埋及释放。所制备的微包纳胶囊表面光洁,球形度较好,胶囊之间无粘连,分散性较好,粒度分布均匀。几丁聚糖分子量、浓度及药物初始浓度对载药量及体外释放影响不一。与单纯微胶囊相比,微包纳胶囊能够显著延长药物的释放时间,从而为该新型载体在大分子药物释放的应用方面提供了实验依据。     

氧化海藻酸钠交联壳聚糖载药复合体系的制备及其药物缓释初步研究

为获得一种新型的药物释放复合体系,本实验首先通过乳化交联法制备壳聚糖(CS)包载四环素(TC)微球,然后利用氧化海藻酸钠交联聚磷酸钙/壳聚糖(CPP/CS)复合材料,用冷冻干燥法制备了载药微球复合体系.并用傅立叶红外光谱仪(IR)、扫描电镜(SEM)及药物的体外释放等方法对该载药微球复合体系进行分析和表征.结果显示,经...     

聚氨基酸复合微胶囊对Hb的控制释放

以生物相容性好、价格低廉的海藻酸钠(ALG)为聚阴离子芯材,通过静电液滴装置制备了平均粒径在290 μm左右、球形度好、表面光洁的海藻酸钙胶珠;再将生物可降解、具有介入治疗作用的聚精氨酸(PLA)与聚组氨酸(PLH)的混合物作为聚阳离子壁材,在海藻酸钙胶珠表面覆上一层高分子聚合膜以制备聚氨基酸复合微胶囊;并以牛血红蛋白Hb为药物模型,对微胶囊的控制释放性能进行了考察并将其初步应用于体外模拟口服给药。结果表明:聚氨基酸复合微胶囊在前0.5 h的累积释放量均低于40％,溶出结束时累积释放量均达到80%以上;ALG/(PLA-PLH)复合微胶囊和ALG/PLH微胶囊的药物释放速率均低于ALG/PLA微胶囊;于10 min成膜时间内制备的微胶囊具有较高的载药量、包封率和缓释性能;以pH 4.6 HAc-NaAc缓冲液为成膜溶媒制备的微胶囊,Hb持续释放时间和残留量均高于蒸馏水组;前2 h在模拟胃液的pH 1.2 HCl溶媒中累计释放的Hb不超过10％且绝大部分是在模拟肠液环境即pH 6.8 PBS 溶媒中释放的;壳聚糖的引入能在一定程度上延长药物释放时间。聚氨基酸复合微胶囊具备一定的缓释性、pH响应性和生理黏附性,有望成为一种口服给药系统用药物载体。      

乳酸-乙醇酸共聚物/壳聚糖复式微球缓释蛋白

采用两次乳化包埋技术制备了一种载蛋白的乳酸-乙醇酸共聚物/壳聚糖复式微球（Poly（lactide-co-glycolide）/chitosan微球,简称PLGA/chitosan微球）。先以复乳法（W/O/W）制备加载牛血清白蛋白（BSA）的PLGA微球,再以壳聚糖（Chitosan）为基体对PLGA微球进行包埋,用...     

涂膜处理对氩气气调包装的鲜切香菇品质的影响

采用海藻酸钠和壳聚糖涂膜处理并结合氩气气调,对鲜切香菇进行包装,检测了鲜切香菇在贮藏中的呼吸强度、失重率、硬度、白度、PPO 活性以及感官评定等指标,研究了不同配比复合液对鲜切香菇贮藏保鲜效果的影响。 结果表明,0. 5% 壳聚糖+1. 5% 海藻酸钠处理组,能有效地抑制鲜切香菇的呼吸速率和失重率,并维持最高的硬度值,且在贮藏后期,其白度值明显高于其他处理组,更易让消费者接受。     

壳聚糖结合脱氢乙酸钠涂膜对槟榔品质的影响

目的以槟榔为实验材料,基于气调贮藏(O2和CO2的体积分数均为4%)技术,探究壳聚糖结合脱氢乙酸钠涂膜对槟榔的保鲜效果。方法采用不同质量分数壳聚糖溶液(0,0.5%,1.0%,1.5%)结合质量浓度为50 mg/L的脱氢乙酸钠对槟榔进行涂膜,测定其在气调贮藏期间对槟榔感官品质、腐烂率、营养品质的影响。结果涂膜后的槟榔各项品质显著优于未涂膜槟榔。结论经壳聚糖(0.5%)/脱氢乙酸钠(50 mg/L)涂膜后的槟榔在贮藏期30 d内能保持良好的品质,能延缓果皮变黄。     

壳聚糖复合保鲜膜制备及其拉伸性能研究

将充分溶胀的壳聚糖与三偏磷酸钠交联并与硅溶胶共混,制备出了壳聚糖复合保鲜膜,用万能拉力机测试了其拉伸性能。研究结果表明,交联和共混明显提高了壳聚糖复合保鲜膜的力学性能,并且壳聚糖浓度在1.2×10-4～1.4×10-4 mol/L,三偏磷酸钠的含量在0.08%,mSiO2∶m壳聚糖约为0.15时,保鲜膜综合力学性能最佳。     

叶酸协同EDC改性高脱乙酰度壳聚糖微球的制备及工艺探究

使用高脱乙酰度壳聚糖制备了靶向药物载体-叶酸改性壳聚糖微球。首先通过碱法制备了高脱乙酰度的壳聚糖,采用酸碱滴定法和傅里叶变换红外光谱(FTIR)对其结构进行了表征,结果表明,经脱乙酰化处理后的壳聚糖脱乙酰度高达93.8%。然后以高脱乙酰度壳聚糖制备了叶酸改性壳聚糖,创新性地发现用1∶1的二甲基亚砜和水的混合溶剂可以得到壳聚糖和叶酸反应的均相体系。通过不同的改性方案,得到了不同改性程度的壳聚糖,改性程度分别达到了2.60%、5.10%、8.75%和9.49%。最后用三聚磷酸钠交联制备了叶酸改性壳聚糖微球,并用激光粒度仪系统地分析了三聚磷酸钠和改性壳聚糖的用量比例及浓度对微球的粒径、Zeta电位的影响。研究发现,随着三聚磷酸钠与改性壳聚糖的比值增大,微球的粒径和Zeta电位都增大,当比值增加到一定的程度,微球的粒径会快速增加。对三聚磷酸钠和改性壳聚糖加入浓度的研究,发现浓度的增大将导致粒径的增大和Zeta电位的降低。     

壳聚糖—聚磷酸钠聚离子复合物渗透汽化膜的研究（I）聚离子复合物膜的制备及特性表征

用长链聚阳离子电解质壳聚糖和短铁聚阴离子聚磷酸钠为膜材料，采用聚离子复合反应的方法制备出一种新型渗透汽化透水膜——壳聚糖—聚磷酸钠聚离子复合物膜．用红外光谱对膜的化学结构进行了分析，证实壳聚糖和聚磷酸钠确实发生了聚离子复合反应，形成了壳聚糖长铁分子与聚磷酸钠短铁分子相互缠结的网状结构．以乙醇—水体系为研究对象，考察了组分在膜内的溶解度和溶解分配关系随体系中乙醇浓度变化的关系，这种溶解过程的热力学分配关系直接支配着膜的渗透汽化分离性能．     

壳聚糖-聚磷酸钠聚离子复合物渗透汽化膜研究(Ⅱ)聚合条件和操作条件对膜分离性能的影响

选用聚阳离子电解质壳聚糖和聚阴离子电解质聚磷酸钠为膜材料，采用聚离子复合反应的方法制备出了一种新型的渗透汽化透水膜：壳聚糖—聚磷酸钠复合物膜(CS—SPP)，通过控制聚离子反应的条件如聚磷酸钠浓度，反应时间，从而改变聚离子反应程度，制备出了不同性能的聚离子膜．研究了壳聚糖-聚磷酸钠聚离子膜分离乙醇／水溶液的特性，探讨了聚离子反应条件、操作条件对膜分离性能的影响．     

Formulation and in vitro evaluation of bisphosphonate loaded microspheres for implantation in osteolysis

Chitosan and poly(lactide-co-glycolide) acid (PLGA) microspheres loaded with alendronate sodium (AS) were prepared for orthopedic as well as dental applications. In orthopedics the aim was to make the total joint prostheses stay in the body for a long time without causing bone tissue loss, while in dentistry it was aimed to treat the alveolar bone resorption caused by periodontitis and also to make the dental treatment using implants easier by reducing the bone loss in patients with osteoporosis. Solvent evaporation method was used to prepare AS loaded PLGA microspheres and emulsion polimerization method was used to prepare AS loaded chitosan microspheres. Particle size, loading efficacy, surface characteristics, and in vitro release characteristics were examined on prepared formulations. After the examination of the scanning electron microscopy photographs of microspheres, chitosan microspheres were observed to have spherical structure and smooth surface characteristics while PLGA microspheres were observed to have spherical porous surface structure. Loading efficacy was found to be 3.30% for chitosan microspheres and 7.70% for PLGA microspheres. It was observed that 85% of AS had been released at the end of the third day from chitosan microspheres whereas 58% was released at the end of the fifth day from PLGA microspheres. It was found that chitosan microspheres gave first order release while PLGA microspheres gave zero order release.     

Development of chitosan/gelatin/keratin composite containing hydrocortisone sodium succinate as a buccal mucoadhesive patch to treat desquamative gingivitis

The aim of this research was to develop chitosan/gelatin/keratin composite containing hydrocortisone sodium succinate as a buccal mucoadhesive patch to treat desquamative gingivitis, which was fabricated through an environmental friendly process. Mucoadhesive films increase the advantage of higher efficiency and drug localization in the affected region. In this research, mucoadhesive films, for the release of hydrocortisone sodium succinate, were prepared using different ratios of chitosan, gelatin and keratin. In the first step, chitosan and gelatin proportions were optimized after evaluating the mechanical properties, swelling capacity, water uptake, stability, and biodegradation of the films. Then, keratin was added at different percentages to the optimum composite of chitosan and gelatin together with the drug. The results of surface pH showed that none of the samples were harmful to the buccal cavity. FTIR analysis confirmed the influence of keratin on the structure of the composite. The presence of a higher amount of keratin in the composite films resulted in high mechanical, mucoadhesive properties and stability, low water uptake and biodegradation in phosphate buffer saline (pH?=?7.4) containing 10⁴?U/ml lysozyme. The release profile of the films ascertained that keratin is a rate controller in the release of the hydrocortisone sodium succinate. Finally, chitosan/gelatin/keratin composite containing hydrocortisone sodium succinate can be employed in dental applications.     

Formulation and In Vitro Evaluation of Bisphosphonate Loaded Microspheres for Implantation in Osteolysis

ABSTRACT

Chitosan and poly(lactide-co-glycolide) acid (PLGA) microspheres loaded with alendronate sodium (AS) were prepared for orthopedic as well as dental applications. In orthopedics the aim was to make the total joint prostheses stay in the body for a long time without causing bone tissue loss, while in dentistry it was aimed to treat the alveolar bone resorption caused by periodontitis and also to make the dental treatment using implants easier by reducing the bone loss in patients with osteoporosis. Solvent evaporation method was used to prepare AS loaded PLGA microspheres and emulsion polimerization method was used to prepare AS loaded chitosan microspheres. Particle size, loading efficacy, surface characteristics, and in vitro release characteristics were examined on prepared formulations. After the examination of the scanning electron microscopy photographs of microspheres, chitosan microspheres were observed to have spherical structure and smooth surface characteristics while PLGA microspheres were observed to have spherical porous surface structure. Loading efficacy was found to be 3.30% for chitosan microspheres and 7.70% for PLGA microspheres. It was observed that 85% of AS had been released at the end of the third day from chitosan microspheres whereas 58% was released at the end of the fifth day from PLGA microspheres. It was found that chitosan microspheres gave first order release while PLGA microspheres gave zero order release.