Fe3O4 包覆聚苯乙烯磁性微球的制备及性能

为研究一种应用于磁稳定流化床反应器的新型高分子磁性微球的制备方法及性能,采用悬浮聚合法制备了Fe_3O_4纳米粒子包覆聚苯乙烯磁性微球,研究了搅拌速率、加入磁性Fe_3O_4纳米粒子的时间等因素对复合微球粒径及性能的影响,运用扫描电子显微镜(SEM)、X射线衍射(XRD)、振动样品磁强计(VSM)、热重(TGA)等测试手段,表征了磁性聚苯乙烯微球的形貌特征、结构、粒径、磁学性能及Fe_3O_4的包覆量.实验结果表明:在搅拌转速为600 r/min,80℃保温10 min加入修饰Fe_3O_4纳米粒子,制备所得的磁性聚苯乙烯微球为粒径分布均匀的球状微粒;Fe_3O_4的包覆量达到5%,最高饱和磁化强度为3.73 emu/g,具有较好的超顺磁性,可应用于磁稳定流化床反应器.     

药用壳聚糖磁性复合微球的制备及特性

采用化学共沉淀法,以FeCl2·4H2O和FeCl3·6H2O为原料,氨水为沉淀剂制备出磁性Fe3O4纳米粒子;然后采用化学交联法,在分散有纳米Fe,04的壳聚糖乳液中,加入适量的戊二醛交联剂制得包覆有纳米Fe3O4的壳聚糖复合微球载体.该复合磁性微球成球性好,分散均匀,平均粒径达到10βμm左右,具有较好的磁响应性及生物可降解特性.该复合磁性微球可作为载体材料应用于磁性靶向药物的制备.     

磁性聚乙烯醇微球的制备及其性质

采用分散聚合法,在Fe3O4磁流体存在下,通过PVA分子单体共聚制备磁性高分子微球.用透射电镜和X射线对磁流体的形貌、粒径进行表征和衍射分析,同时借助于显微拍照和红外光谱,对磁性微球的微观形貌和化学成分进行了研究.通过对比磁性微球的磁响应性及粒径,研究了反应温度、搅拌速度、聚乙烯醇用量、盐酸用量等操作因素对磁性微球性质的影响.结果表明,在70 ℃操作温度、750 r/min的搅拌速度,5ml 9%PVA和0.5 ml 37%盐酸条件下能制备出粒径在8～44 μm之间、具有良好磁响应性、表面富含羟基和羧基等官能团的磁性聚乙烯醇微球.     

静电喷雾法制备壳聚糖/康普瑞丁载药微球

本研究采用静电喷雾法,以壳聚糖为基质材料,康普瑞丁为模型药物制备微球。实验中采用AcOH/H2O和AcOH/H2O/EtOH两种溶剂,分析了微球形貌和粒径分布的影响因素,并且对CS-CA4微球的缓释性能进行了测定。结果表明,壳聚糖浓度、溶剂配比及乙醇和康普瑞丁的加入会使壳聚糖微球呈球状、中间塌陷的类球状、棒状等不同形貌,微球粒径存在较大差异;通过AcOH/H2O/EtOH复合溶剂将疏水性药物康普瑞丁载入壳聚糖微球,制备出的壳聚糖/康普瑞丁载药微球分散性好,粒径分布均匀,平均粒径仅为0.27μm;使用戊二醛蒸汽交联48h的微球缓释效果明显。     

原位聚合制备PLLA/Fe3O4磁性复合微球及其表征

介绍了一种新的PLLA/Fe3O4磁性复合微球的制备方法——表面引发开环聚合法,先利用硅烷偶联剂Z-6040对Fe3O4进行改性,在其表面引入羟基,再通过羟基引发丙交酯在磁粒子表面开环聚合制备PLLA/Fe3O4磁性复合微球。探讨了复合微球的形成机理,对磁粒子改性效果和微球形貌、粒径、结构、磁含量及磁性能等进行了表征,并详细研究了磁性复合微球性能的影响因素。     

磁性γ-Fe2O3/聚(苯乙烯-二乙烯苯)复合材料的制备及性能研究

以苯乙烯(St)、二乙烯苯(DVB)为共聚单体、MAA为功能单体,以十二烷基笨磺酸钠(SDBS)和油酸(OA)为双层表面活性剂修饰的磁性γ-Fe2O3为磁性来源,制备表面亲水性的磁性无机-有机复合材料.详细探讨了功能单体MAA对磁性复合材料中磁含量和复合材料表面亲水性能的影响.分别用扫描电子显微镜(SEM)、光学显微镜(OM)、热重分析仪(TGA)及吸水率对磁性复合材料的形貌、磁性粒子分布情况、磁含量、表面亲水性等进行表征.结果表明,随着MAA浓度的增加,磁性复合粒子的粒径变小且分布变窄,复合材料的磁含量增加和表面亲水性增强.SEM和OM测试表明,磁性聚合物复合粒子球形度好且粒径分布变窄,磁性复合材料的稳定性好,磁粉含量高达17.81%.     

磁性聚乙烯醇微球的制备及其性质

采用分散聚合法，在Fe3O4磁流体存在下，通过PVA分子单体共聚制备磁性高分子微球。用透射电镜和X射线对磁流体的形貌、粒径进行表征和衍射分析，同时借助于显微拍照和红外光谱，对磁性微球的微观形貌和化学成分进行了研究。通过对比磁性微球的磁响应性及粒径，研究了反应温度、搅拌速度、聚乙烯醇用量、盐酸用量等操作因素对磁性微球性质的影响。结果表明，在70℃操作温度、750r／min的搅拌速度，5ml9％PVA和0．5ml37%盐酸条件下能制备出粒径在8～44μm之间、具有良好磁响应性、表面富含羟基和羧基等官能团的磁性聚乙烯醇微球。     

载药纳米Fe_3O_4/羧化壳聚糖磁性液体的制备与表征

采用化学共沉法制备Fe3O4磁性微粒,用水溶性较好的羧化壳聚糖及用于治疗基底细胞瘤、光化性骨化病的氨基酮戊酸对Fe3O4磁性微粒进行两层包覆,最终形成载药Fe3O4/羧化壳聚糖磁性液体。采用XRD、TEM和FT-IR对载药纳米Fe3O4/羧化壳聚糖磁性液体复合微球的晶型结构、官能团组成及微粒尺寸和形貌等进行了表征。检测结果说明,制备的载药纳米Fe3O4/羧化壳聚糖磁性液体,其核心组份为晶型较好的Fe3O4磁性纳米微粒,磁性微粒的粒径范围为9~11nm;载药Fe3O4/羧化壳聚糖磁性复合微球成类球状;氨基酮戊酸、羧化壳聚糖和Fe3O4分子间发生了化学键的作用;在外加磁场作用下,观察到载药磁性液体的定向移动,有望实现在肿瘤治疗上的主动靶向给药作用。     

Fe3O4／壳聚糖纳米微球的制备与表征

采用原位聚合法制备分散性良好、粒径在300nm以下、兼具磁性能与荧光性能的Fe3O4／壳聚糖纳米微球,通过XRD、IR和SEM等对产物的组成、结构和微观形貌进行表征,利用荧光光谱分析Fe3O4壳聚糖纳米微球进行光学性能测试,实验结果表明,通过交联反应,Fe3O4被壳聚糖所包覆,产物显示出了非常好的荧光性能,并且在外加磁场下具有明显的磁响应行为。     

磁性γ-Fe2O3／聚（苯乙烯一二乙烯苯）复合材料的制备及性能研究

以苯乙烯（St）、二乙烯苯（DVB）为共聚单体、MAA为功能单体,以十二烷基苯磺酸钠（SDBS）和油酸（OA）为双层表面活性剂修饰的磁性γ-Fe2O3为磁性来源,制备表面亲水性的磁性无机一有机复合材料。详细探讨了功能单体MAA对磁性复合材料中磁含量和复合材料表面亲水性能的影响。分别用扫描电子显微镜（SEM）、光学显微镜（OM）、热重分析仪（TGA）及吸水率对磁性复合材料的形貌、磁性粒子分布情况、磁含量、表面亲水性等进行表征。结果表明,随着MAA浓度的增加,磁性复合粒子的粒径变小且分布变窄,复合材料的磁含量增加和表面亲水性增强。SEM和0M测试表明,磁性聚合物复合粒子球形度好且粒径分布变窄,磁性复合材料的稳定性好,磁粉含量高达17．81％。     

光热敏感型羧甲基壳聚糖纳米微球的制备及光热性能

羧甲基壳聚糖因其具有良好的水溶性和生物相容性,被广泛应用于生物医学领域。以天然可降解高分子羧甲基壳聚糖为载体,在引发剂过硫酸钾的作用下,通过自由基组合法将N-异丙基丙烯酰胺接枝到羧甲基壳聚糖上,然后在香草醛的交联作用下,采用乳化交联法制备一种负载光敏剂吲哚菁绿(ICG)的新型光热敏感型羧甲基壳聚糖微球,通过傅里叶红外(FT-IR)、核磁(1H-NMR)及扫描电镜(SEM)对共聚物结构及微球形貌进行表征,考察了油水比、转速、香草醛、乳化时间对该纳米微球包载阿霉素载药量的影响,并研究了其光热性能。结果表明,FT-IR和1H-NMR分析证明,N-异丙基丙烯酰胺成功接枝到羧甲基壳聚糖上;SEM分析可知,纳米微球外观呈球状,分布均匀,平均粒径为143 nm。油水比为20∶1,转速为600 r/min,香草醛量为1 mL,乳化时间3 h的微球载药量最高为19.32%。同时,通过改变外界环境条件,纳米微球能缓慢靶向释放药物,具有良好的光热敏感性,该纳米微球在药物控释及药物载体等领域有广泛的应用前景。     

新型水溶性壳聚糖盐酸盐微球的制备与表征

以水溶性壳聚糖盐酸盐为原料,戊二醛为交联剂,采用乳化交联法制备了壳聚糖盐酸盐微球。通过多种理化手段检测及体外MG63细胞共培养对壳聚糖盐酸盐微球的形貌结构、尺寸大小、粒径分布、成球机理、结晶度、热稳定性及细胞相容性进行了测试及表征,并与普通酸溶性壳聚糖制备的微球进行比较。结果表明水溶性壳聚糖盐酸盐与戊二醛通过Schiff碱反应产生交联,易成球,球形圆整光滑;粒径分布较窄,粒径约为5～10μm;微球结晶度较低,其热稳定性较壳聚糖盐酸盐原料和酸溶性壳聚糖微球均有提高;细胞相容性良好。该微球表现出与酸溶性壳聚糖微球相似的理化性质,但因其原料为水溶性,微球制备条件更为温和,在药物载体研究领域有望得到更广泛的应用。     

蔗糖/水体系磁性聚苯乙烯微球的制备及其表征

以氧化法制备Fe_3O_4磁流体,首次采用蔗糖水溶液为分散介质,以聚乙烯醇为稳定剂,偶氮二异丁腈为引发剂,悬浮聚合法合成了磁性聚苯乙烯微球.该蔗糖水反应体系对环境无污染且后处理简单.考察了蔗糖、苯乙烯(St)、Fe_3O_4磁流体、稳定剂、引发剂的含量等条件对微球的粒径及其分布的影响.所合成的磁性聚苯乙烯微球具有核壳型结构,有较强的磁响应性能,球形和分散度良好,粒径为80～85μm.采用红外光谱、振动样品磁强计和光学显微镜对磁性聚苯乙烯微球进行了表征.     

Properties of magnetic poly(glycidyl methacrylate) and poly(N-isopropylacrylamide) microspheres

Iron oxide colloids were prepared by coprecipitation of Fe(II) and Fe(III) salts in alkaline media and stabilized by perchloric acid, oleic acid, or poly(acrylic acid). In an attempt to obtain magnetic polymer microspheres differing in size, dispersion polymerization of glycidyl methacrylate (GMA) in ethanol containing HClO₄-stabilized magnetite, dispersion copolymerization of GMA and 2-hydroxyethyl methacrylate (HEMA) in toluene/2-methylpropan-1-ol mixture in the presence of oleic acid-coated magnetite, and inverse suspension copolymerization of N-isopropylacrylamide (NIPAAm) and N,N′-methylenebisacrylamide (MBAAm) in cyclohexane in the presence of poly(acrylic acid)-coated maghemite were compared. The microspheres were characterized by morphology, size, polydispersity, and some magnetic properties.     

A novel method for the synthesis of polyamide 6 magnetic microspheres

Polyamide 6 (PA6) magnetic microspheres were firstly prepared via successively in situ polymerization using phase inversion technology of polymer pairs polyamide 6/polystyrene (PA6/PS) at extremely low PS content. The properties of PA6 magnetic microspheres, such as morphologies, diameter size distribution, magnetic properties, thermal stability, and the functional groups of the magnetic microspheres, were investigated by different techniques (i.e. SEM, TEM, DLS, VSM, FTIR, and DSC). The results indicated that the diameter distribution of PA6 magnetic microspheres was narrow, and the mean diameter size was about 7.7 μm. The saturation magnetization of magnetic microspheres reached 12.50 emu/g. Furthermore, the magnetic microspheres had abundant functional groups and better thermal stability.     

非均相悬浮法制备多孔羟基磷灰石微球

为了获得具有吸附和生物学功能的多孔羟基磷灰石(HA)微球,以自制的纳米羟基磷灰石(HA)粉体为原料,用非均相悬浮法制备了HA/明胶微球,将微球在1 250℃下焙烧,成功制备了直径100~500μm的多孔HA微球.采用光学显微镜、SEM分析、XRD分析和BET氮吸附法研究了微球形貌、尺寸、物相组成、比表面积和孔径,测定了微球对水中F-离子的吸附性能.结果表明:微球具有良好球形形貌和相互贯通的纳米微孔;尺寸比较均匀,分散性良好;微球的主要结晶相为羟基磷灰石;BET表面积为1.867 0~2.089 5 m~2/g,孔径6.53~6.85 nm;对氟离子的平衡吸附容量为1.909~1.940 mg/g.通过控制m(HA)/m(明胶)比例、油温、搅拌速度和搅拌时间,可以在一定范围内控制微球直径和比表面积.     

The synthesis and characterization of polymer coated iron oxide microspheres

For biomedical applications drug carrying polymers are coated around magnetic iron oxide particles to form microspheres. In the present study, the iron oxide powder was ball milled. Microspheres were then synthesized by solvent evaporation, resulting in iron oxide particles encapsulated in a polymer and drug coating. Various parameters, such as the duration of milling and agitation speed as well as the polymer concentration were varied. A milling time of 72 h was found to yield a small size and narrow size distribution of particles; the average particle size was about 600 nm. Measurements of the change in grain size and the magnetic properties of the powder with milling time were performed. It was determined that the size of the microspheres was not sensitive to the initial particle size, but it could be decreased by variation of agitation speed or polymer concentration. The agitation speed and polymer concentration of 400 rpm and 0.04 g poly(l-lactic acid) in 8 g dicholoromethane, respectively, was found to yield small, spherical microspheres with a narrow size distribution. The surface morphology and magnetic properties of the microspheres was also analyzed.     

微波辐射下交联壳聚糖微球的制备及吸附性能研究

微波辐射下,以壳聚糖为原料,甲醛为预交联剂,环氧氯丙烷为交联剂,制得甲醛环氧氯丙烷交联壳聚糖微球树脂,研究了合成条件对微球吸附性能的影响,并采用傅里叶红外光谱仪和电子扫描电镜对树脂的微观结构和形貌进行表征。结果表明,树脂具有很好的球形;Shiff碱反应能够很好地保护壳聚糖上的氨基;交联剂用量、搅拌速率和酸处理条件对树脂的吸附性能的影响较大。当合成条件为搅拌速率600r/min、甲醛1.5mL、环氧氯丙烷3mL、酸化时间8min、盐酸用量30mL,所得交联壳聚糖微球对Cu(Ⅱ)的吸附容量可达到269.83mg/g。     

Fabrication and characterization of chitosan microspheres agglomerated scaffolds for bone tissue engineering

In the presented paper authors describe a method for bone scaffolds fabrication. The technique is based on the agglomeration of chitosan microspheres. The fabrication process is complex and consists of a few steps: chitosan spheres extrusion, scaffold formation by compression followed by the spheres agglomeration and bonding with cross-linking agent (STPP, sodium tripolyphosphate). The described method allows manufacturing of porous materials with controllable shape, pore size distribution and their interconnectivity. In this technique 3D scaffold porosity can be regulated by altering spheres diameter. Authors studied influence of cross-linker concentrations and time of cross-linking process on the scaffold morphology, mechanical properties, enzymatic degradation rate (in the presence of lysozyme) and human osteoblasts response. Surface morphology and topography were evaluated by SEM. Porosity and pore interconnectivity were observed via μCT scanning. Mechanical tests showed that chitosan scaffolds perform compression characteristic (Young Modulus) similar to natural bone. Cytotoxicity established by XTT assay confirmed that most of the developed composite materials do not show toxic properties. Osteoblast adhesion and morphology were analyzed by SEM and optical microscopy.     

Preparation of paclitaxel-loaded microspheres with magnetic nanoparticles

The objective of this paper was to prepare paclitaxel-loaded microspheres, a kind of target-orientation anticancer drug. The paclitaxel-loaded microspheres were prepared with magnetic Fe₃O₄ nanoparticles and taxol. The morphology was characterized by scanning electron microscopy (SEM), and the average size and the size distribution were determined by a laser-size distributing instrument. High performance liquid chromatography (HPLC) was used to measure the paxlitaxel content. Experimental results indicated that the effective drug loading and the entrapment ratio of paclitaxel-loaded microspheres were 1.83% and 92.62%, respectively.