口服疫苗微球研究进展

近二十年来 ,生物技术药物 (ｂｉｏｔｅｃｈｄｒｕｇｓ)的发展突飞猛进 ,已日益受世人瞩目。其中生物技术疫苗迅速增加 ,用于癌症、艾滋病、类风湿性关节炎、镰刀形贫血、骨质疏松症、乙型肝炎及其它感染性疾病[1] 。但这类药物在口服时存在生物利用度低、物理化学稳定性差、体内半衰期短等缺点 ,致使它们常常只能采用频繁地注射给药 ,其使用与保存十分不便。口服疫苗微球则是一种有效的新制剂 ,它能满足人们对给药次数最少的需要 ,并可实现在膜表面的诱导免疫。国内对口服疫苗微球研究较少 ,本文从口服疫苗微球的特点、制备与体外释放、胃…     

壳聚糖微球作为口服疫苗载体的应用

壳聚糖是一种被广泛应用的天然聚合物,其特殊的物理化学性质和生物特性为口服疫苗微球载体的研究提供了一条新途径,壳聚糖在口服疫苗呈递中有广阔的应用前景。此文就壳聚糖微球作为口服疫苗载体的应用进行综述。     

可生物降解微球作为口服疫苗载体的研究进展

本文主要介绍可生物降解微球作为口服疫苗载体的优越性,以及微球疫苗的制备工艺、体外释放动力学、口服后的体内分布、免疫机理、口服质粒ＤＮＡ微球疫苗的研究进展。     

可生物降解微球作为口服疫苗载体的研究进展

本文主要介绍可生物降解微球作为口服疫苗载体的优越性 ,以及微球疫苗的制备工艺、体外释放动力学、口服后的体内分布、免疫机理、口服质粒 DNA微球疫苗的研究进展     

鸡新城疫病毒抗膀胱癌作用的体内、体外实验研究

目的：研究鸡新城疫病毒（ＮＤＶ）对膀胱癌细胞在体内、体外杀伤作用。方法：采用了细胞培养和计数、光镜、电镜观察的方法及小鼠膀胱肿瘤模型（ＢＳＴ７３９）进行研究。结果：体外实验中,ＮＤＶ组、卡介苗组及丝裂霉素Ｃ组对膀胱癌细胞均有明显的杀伤作用;用透射电镜观察ＮＤＶ作用后的膀胱癌细胞,发现胞浆中有病毒颗粒,体内实验证明,ＮＤＶ、丝裂霉素Ｃ和止疥苗对膀胱癌细胞都有一定的杀伤作用;在瘤内瘤对侧注射ＮＤＶ对膀     

胰岛素肠溶微球口服的实验研究

目的 :研制一种可供口服的胰岛素肠溶微球。方法 :采用相分离法制备胰岛素丙烯酸树脂微球 ;建立放射性免疫法测定微球包封率 ;利用体外实验法考察微球的抗酸及肠溶能力 ;将不同处方的微球给大鼠灌胃 ,测定其血糖变化。结果 :制得微球粒径分布在 2～ 7μm ;包封率 95 .17% ;在人工胃液中 2h有少于 14%的胰岛素释放 ;在人工肠液中 1h内胰岛素的释放度达 96 % ;微球可使大鼠产生明显的降血糖效果。结论 :胰岛素口服肠溶微球是一类具有发展前景的制剂。     

包裹B细胞表位的PLG微球作为口服乙型肝炎疫苗的研究

印度皮革研究所Rajkannan等将代表HBsAg B细胞表位127-145残基的多肽(BCEP)包裹人丙交醋、乙交醋共聚物( PLG)作为口服乙型肝炎疫苗进行了研究。通过W/O/W双乳剂-溶剂燕发法制备BCEP的PLG微球(BCEM),平均直径10μm,BCEP包裹效率为64%。体外释放研究结果     

紫杉醇微球制备的初步研究

目的制备紫杉醇微球(囊).方法以明胶(A)作为包合囊材,采用单凝法,以适当的材料作为阻滞剂,对紫杉醇原料进行包合制备微球并对制备工艺进行了初步的研究.结果以10%的明胶液体、控制转速(240±10)r·     

口服利福平海藻酸钠微球的制备

［摘要］目的研制口服利福平海藻酸钠微球。方法采用静电液滴法制备利福平海藻酸钠微球，测定粒径大小、包封率、载药量及其影响因素，考察微球的体外释放特点。结果微球球形圆整，分散性好，平均粒径70.2 μm，包封率83.5%，载药量17.1%，在模拟肠液中的释放呈快慢相，时间长而药物释放完全。结论以海藻酸钠、硬脂酸为材料，用静电液滴法制备利福平微球，球径小、包封率高、释药时间长，工艺简便。     

口服胸腺肽微球的研究

目的：制备胸腺肽微球,并研究其性质。方法：以邻苯二甲酸醋酸纤维素为成球材料,胸腺肽为球心物,制备工艺经均匀设计优化。结果：得到白色粉末状微球。微球载药量３１．２±１．４％。平均粒径１５．６ｍ。微球在ＨＭ胃液中２ｈ释药不超过１０％,在人工肠液中２ｈ释药１００％。微球给大鼠灌胃后,ＨＰＬＣ测得大鼠血中胸腺肽浓度在２～３ｈ最高。结论：制备的胸腺肽微球可口服吸收。     

Virosome and ISCOM vaccines against Newcastle disease: preparation, characterization and immunogenicity

The purpose of this study was to prepare and characterize virosomes and ISCOMs containing envelope proteins of Newcastle disease virus (NDV) and to evaluate their immunogenicity in target animals (chickens). Virosomes were prepared by solubilization of virus with either Triton X-100 or octyl glucoside (OG) followed by detergent removal. Biochemical analysis revealed that these virosomes contained both the haemagglutinin-neuraminidase protein (HN) and the fusion protein (F), with preserved biological activity. Acidic environment triggered the fusion between virosomes and chicken erythrocyte ghosts. Formation of ISCOMs was achieved by solubilizing phospholipids, cholesterol, envelope protein antigen and Quil A in Triton X-100. The ISCOM particles were formed by removal of the detergent. In each formulation the relative HN content correlated with the capability to agglutinate red blood cells. The immunogenicity of these lipid-based subunit vaccines was determined in chickens after subcutaneous immunization. The relative HN content of the subunit vaccines correlated with the haemagglutination-inhibition (HI) antibody titres. Virosomes prepared with Triton X-100 and ISCOMs offered high clinical protection (> 80%) upon challenge with virulent NDV. Virosomes prepared with OG yielded lower clinical protection despite high HI antibody titres. Virosomes with reduced antigen density showed poor immunogenicity and protection. In conclusion, ND virosomes and ISCOMs were found to be immunogenic and provided good protection.     

Oral Immunization of Rats with Proteinoid Microspheres Encapsulating Influenza Virus Antigens

Influenza virus antigen microspheres were prepared by a pH-dependent process using a protein-like polymer (proteinoid) made by thermal condensation of amino acids. The efficacy of these preparations to induce specific IgG responses when used as oral vaccines in rats was evaluated. A single enteric dose of Ml entrapped in proteinoid microspheres was able to induce a significant IgG response to Ml as early as 2 weeks postdosing, while rats dosed orally with the same Ml total dose (no microspheres) showed no detectable antibody response. An unencapsulated hemagglutinin and neuraminidase (HA-NA) preparation induced a moderate anti HA-NA IgG response. A single enteric dose of HA-NA spheres induced a response in 33% of the rats; this response was up to eight times higher than that observed in the rats dosed with unencapsulated antigen.     

Microencapsulation of Hepatitis B Core Antigen for Vaccine Preparation

Purpose. To prepare poly(lactide-co-glycolide)(PLGA) microspheres containing recombinant hepatitis B core antigen (HBcAg; Mw = 3,600,000) by a w/o/w emulsion/solvent evaporation method and evaluate the possibility of this system as a potent long-acting carrier for hepatitis B core antigen in mice. Methods. Various additives had been incorporated in the internal aqueous phase during the process of microencapsulating HBcAg, HBcAg antigenicity in the medium extracted from the prepared microspheres were measured by ELISA. Shape confirmation of the HBcAg antigen was performed by a sucrose gradient velocity centrifugal technique. For in vivo study, prepared microspheres were administered subcutaneously to Balb/C mice, and the serum IgG level was determined by ELISA. Results. The inactivation of HBcAg by methylene chloride was dramatically reduced by the addition of gelatin (4–8% (w/v)) to the internal aqueous phase during the preparation. Further improvement of the loading efficiency to almost 61% resulted with cooling (4°C). The prepared microspheres (4.27 m ± 1.23 m) containing 0.15% HBcAg displayed burst release (50–60% within 2 days). In subcutaneous inoculation, the adjuvant effect of PLGA microspheres was almost the same as that of the complete Freund's adjuvant. Whereas oral inoculation using the microspheres was not effective. Conclusions. The pH of the added gelatin seemed to be the key to the stabilization of HBcAg from various stability tests and CD spectrum study. Finally, the possibility of using this system as a potent long-acting hepatitis B vaccine was demonostrated.     

Determinants of Release Rate of Tetanus Vaccine from Polyester Microspheres

Controlled-release formulations based on poly(lactic) (PLA) and poly(lactic/glycolic) acid (PLGA) microspheres containing tetanus vaccine were designed. The polymers forming the microspheres were L-PLA of different molecular weights and DL-PLGA, 50:50. These microspheres were prepared by two solvent elimination procedures, both using a double emulsion, and were characterized for size, morphology, and toxoid release kinetics. The influence of formulation variables such as polymer type, vaccine composition, and vaccine/polymer ratio was also investigated. Both techniques yielded microspheres with similar size, morphology, and release properties. Microsphere size was dependent on the type of polymer and the presence of the surfactant L--phosphatidylcholine, which led to a reduction in microsphere size. On the other hand, the release kinetics of encapsulated protein were affected by the polymer properties (ratio lactic/glycolic acid and molecular weight) as well as by the vaccine composition, vaccine loading, and microsphere size. Moreover, for some formulations, a decrease in microsphere size occurred simultaneously, with an increase in porosity leading to an augmentation of release rate. The changes in the PLA molecular weight during in vitro release studies indicated that release profiles of tetanus toxoid from these microspheres were only marginally influenced by polymer degradation. A significant fraction of protein (between 15 and 35%) was initially released by diffusion through water-filled channels. In contrast, the decrease in the PLGA molecular weight over the first 10 days of incubation suggested that erosion of the polymer matrix substantially affects protein release from these microspheres. Among all formulations developed, two differing in microsphere size, polymer hydrophobicity, and release profile were selected for in vivo administration to mice. Administration of both formulations resulted in tetanus neutralizing antibody levels that were higher than those obtained after administration of the fluid toxoid.     

疫苗检定用麻疹病毒抗血清的制备

目的:制备麻疹病毒抗血清,用于含麻疹病毒成分的联合减毒活疫苗的检定。方法:制备麻疹病毒Edm-3株病毒收获液,加入弗氏佐剂,对家兔和豚鼠分别经皮下多点或腹腔途径免疫3针,采血制备抗血清,经除菌过滤和补体灭活后,对抗血清进行中和效价、中和能力、细胞毒性及特异性检测。结果:用4种免疫方式制备的抗血清中和效价均高于1∶320...     

Immune Augmentation of Single Contact Hepatitis B Vaccine by Using PLGA Microspheres as an Adjuvant

The present study was aimed to replace the alum type adjuvant for hepatitis B vaccine. The hepatitis B vaccine was encapsulated in poly (DL-lactide-co-glycolide) microspheres by solvent evaporation technique. The formulated microspheres were characterized in terms of morphology, particle size analysis, in vitro release study and in vivo immune response in male Wistar rats. The FT IR spectrum illustrates the characteristics bands of poly (DL-lactide-co-glycolide) microspheres and hepatitis B vaccine at 1750 cm^-1 and 1650 cm^-1, respectively. The hepatitis B vaccine loaded poly (DL-lactide-co-glycolide) microspheres were able to release antigens till day 42. Significant enhancement of specific antibodies to HBsAg was produced till day 90 after a single administration of HBsAg encapsulated poly (DL-lactide-co-glycolide) microspheres. However, the conventional alum adsorbed hepatitis B vaccine was not found to produce any significant specific antibody levels till day 90 after a single dose. The results showed that poly (DL-lactide-co-glycolide) microspheres show potential as an adjuvant for hepatitis B vaccine.     

妊娠期口腔疾病患者的治疗

目的总结对孕妇进行口腔门诊治疗的经验。方法对422例在口腔门诊治疗的孕妇加强心理辅导,提高良好就诊环境和合适治疗方法,就诊时注意体位调整、血压的监控与胎心及测量,进行口腔健康宣教和电话回访。结果妊娠合并口腔疾病患者治疗效果良好。结论妊娠合并口腔疾病患者的治疗不应被拒绝,而是应提供合适的治疗。     

新城疫病毒对荷瘤小鼠的抑瘤作用

目的 观察新城疫病毒（NDV）对裸鼠人肺癌移植瘤的抗肿瘤作用。方法 建立人肺腺癌细胞系spc-a-1在裸小鼠皮下移植瘤动物模型,瘤体内1次注射NDV病毒作抗肿瘤研究,同时设PBS对照,观察6周,绘制肿瘤生长曲线,比较两组肿瘤体积变化。结果 NDV组肿瘤生长迟缓,PBS组肿瘤生长迅速,6周后PBS组瘤重明显大于NDV组（P〈0．01）。结论 NDV对裸小鼠人肺腺癌移植瘤有明显的抑制作用。     

Dose and Load Studies for Subcutaneous and Oral Delivery of Poly(lactide-co-glycolide) Microspheres Containing Ovalbumin

Poly(lactide-co-glycolide) microspheres containing different loads of OVA (0.05, 0.1, 0.5 and 1.0% w/w) were manufactured by a w/o/w emulsion/solvent evaporation method. Low load efficiencies of less than 20% were observed. Normal size distributions with mean volume diameters ranging from 3.7 to 4.7 µm were obtained for different batches. The in vitro release of OVA from different loaded microspheres showed an expected burst release with all batches. The in vivo dose study (1, 10, 25, 50 µg of OVA) was performed by subcutaneous and oral inoculation in mice by single (0 week) or double (0 and 3 weeks) administration of PLGA 50/50 microspheres containing 0.1% OVA. Subcutaneous administration showed an immune response (serum Ig levels by ELISA) statistically (Fishers paired t-test; P < 0.05) above OVA saline negative controls at 3, 6 and 12 weeks after administration. Oral administration of microspheres produced statistically higher systemic immune responses at the higher doses. Single and double inoculation orally and subcutaneously produced similar serum antibody levels. The in vivo load study was performed by subcutaneous and oral administration to mice of 25 µg OVA contained in various loaded (0.05, 0.1, 0.5 and 1.0% w/w) microspheres. Serum immune responses at 3, 6, and 12 weeks after inoculation were statistically above OVA saline controls and were inversely proportional to the OVA load using either route. This observation suggested a relationship between the number of microspheres delivered and the in vivo serum response. Single subcutaneous administration of 0.05 or 0.1% OVA loaded PLGA 50/50 microspheres induced larger immune responses compared with complete Freunds adjuvant.