番茄红素脂质体的制备

目的:制备番茄红素脂质体。方法:采用薄膜-超声法制备番茄红素脂质体,通过均匀设计法优化出了番茄红素脂质体的组分及制备工艺,应用高效液相色谱法测定番茄红素的含量,用差示扫描量热法检测番茄红素脂质体各组成物质的相变过程。结果:番茄红素脂质体的最佳配方比为:番茄红素:胆固醇:磷脂=3:10:100;最佳水合介质是0．0lmol/L PBS(含0．5%五聚甘油硬脂酸酯);最适洗膜温度为3l℃。结论:番茄红素脂质体呈均一大单室型,有效粒径0．7μm,最大包封率68%。     

葡萄糖氧化酶脂质体的制备与表征

以大豆卵磷脂和胆固醇作为壁材,采用薄膜蒸发-冻融法制备葡萄糖氧化酶脂质体。以包封率作为指标,通过单因素和正交试验设计优化确定最佳制备工艺,并考察脂质体的形貌、粒径分布和稳定性指标。结果表明：最佳工艺参数为：大豆卵磷脂与胆固醇质量比4∶1、芯材质量5 mg（500 U）、水化时间15 min、冻融循环10 次,此条件下包封率可达到（87.7±2.1）%;粒径分布均匀,分散性较好,平均粒径为（164.75±2.55） μm;4 ℃和室温（23.0±0.5）℃贮存条件下脂质体包封率无变化,酶活性稳定。     

白藜芦醇固体脂质体制备工艺研究

采用乙醇注入法制备白藜芦醇脂质体,用冷冻干燥技术制备固体脂质体。以包封率为考察指标,对芯材与壁材的配比、乳化剂的种类和用量、冻干保护剂甘露醇使用量、油水相之比分别进行单因素考察。结果表明：最优制备工艺条件为m(卵磷脂):m(胆固醇):m(白藜芦醇)=10:2:1、乳化剂Tween 80、乳化剂用量0.2%(m/m)、冻干保护剂甘露醇使用量2%(m/m)、油水相体积比为1:10。最优工艺制得的白藜芦醇固体脂质体的包封率为84.68%,采用乙醇注入法可制得包封率高的白藜芦醇固体脂质体,且方法简便易行。     

大豆磷脂阿奇霉素阳离子脂质体的制备及性质研究

利用大豆粉状磷脂,采用薄膜法结合冻融法制备阿奇霉素阳离子脂质体,以高效液相色谱法为分析手段,采用反透析法测定阿奇霉素脂质体的包封率.研究了阿奇霉素脂质体配方中不同成分的比例.阿奇霉素脂质体的最佳制备条件为:水浴温度为40℃,m(阿奇霉素):m(磷脂)=1:25,m(阿奇霉素):m(维生素E)=40:1,m(阿奇霉素):m(十八胺)=2.5:1,加入10%的麦芽糖水溶液为20mL,在此条件下,阿奇霉素阳离子脂质体的包封率为76.07%.从形态、粒径、体外释药特性等方而对阿奇霉素脂质体进行了质量评价,并研究在小鼠体内的分布.     

叶酸脂质体制备工艺优化及其稳定性研究

以叶酸为载药,卵磷脂和胆固醇为膜材,采用薄膜水化- 超声法制备叶酸脂质体;通过单因素考察制备工艺对包封率的影响以及正交设计法进行制备工艺优化。得出最佳制备工艺为卵磷脂与胆固醇比5:1(m/m)、叶酸质量浓度1.4mg/mL、制备温度60℃、水相pH8.0。制备的叶酸脂质体包封率可达到30.36%,平均粒度为335.4nm。将脂质体在4℃下密闭放置15d,以脂质体的粒径变化为指标考察其稳定性。结果表明,脂质体悬液粒径无明显变化,主要集中在300～400nm,脂质体悬液稳定性良好。     

大豆磷脂阿奇霉素脂质体的制备及渗漏率研究

利用大豆粉状磷脂,用薄膜法制备阿奇霉素脂质体,以高效液相色谱法为分析手段,采用反透析法测定阿奇霉素脂质体的包封率.研究了阿奇霉素脂质体配方中不同成分的比例以及水合介质对脂质体包封率的影响.阿奇霉素脂质体的最佳制备条件为:温度38℃,m(阿奇霉紊):m(磷脂)=1:25,m(阿奇霉素):m(胆固醇)=1:2.5,m(阿奇霉素):m(十八胺)=5:1,加入的磷酸盐缓冲溶液为20mL,在此条件下,阿奇霉素脂质体的包封率为75.68%.该方法准确,可用于大豆磷脂阿奇霉素脂质体的制备,并且制备的脂质体稳定.     

大豆磷脂罗红霉素脂质体的制备及渗漏率研究

利用大豆粉状磷脂,采用薄膜法结合冻融法制备罗红霉素脂质体,采用紫外分光光度法测定罗红霉素脂质体的包封率.研究了罗红霉素脂质体配方中不同成分的比例,以及水合介质对脂质体包封率的影响.罗红霉素脂质体的最佳制备条件为:即水浴温度为40℃,m(罗红霉素):m(磷脂)=1∶25,m(罗红霉素)∶m(维生素E)=100∶1,m(罗红霉素)∶m(胆固醇)=1∶2,水合介质为6%的甘露醇溶液,加入的6%的甘露醇溶液为20 mL,在此条件下,罗红霉素脂质体的包封率为63.98%.该方法准确,可用于大豆磷脂罗红霉素脂质体的制备,并且制备的脂质体稳定.     

大豆磷脂克拉霉素脂质体制备及性质研究

采用薄膜冷冻法制备了克拉霉素脂质体,以高效液相色谱法为分析手段,采用反透析法测定克拉霉素脂质体的包封率,并通过正交实验确定了最佳制备条件为:水浴温度为45℃,m(克拉霉素):m(磷脂)=1:35,m(磷脂):m(胆固醇)=4:1,m(有机相):m(水相)=4:1,水合介质为pH6.8的磷酸盐缓冲溶液。在此条件下,克拉霉素脂质体的包封率达到81%,并从形态、粒径、渗漏率等方面对克拉霉素脂质体进行了质量评价。     

VC脂质体的制备与稳定性测定

以卵磷脂和胆固醇为膜材,采用薄膜- 超声法制备VC 脂质体。通过单因素考察生产工艺对包封率的影响以及正交设计法进行工艺优化。得出制备VC 脂质体最佳工艺：制备温度65℃、卵磷脂:胆固醇=5:1、总脂材:VC=25:1、总脂材:表面活性剂(吐温-80)=10:2,在此条件下包封率可达42.1%,平均粒度为373.9nm;将脂质体在4℃下密闭放置15d,以脂质体的粒径变化为指标考察其稳定性。结果表明,脂质体悬液粒径无明显变化,脂质体悬液稳定性良好。     

中链脂肪酸脂质体的制备及其性质测定

以卵磷脂和胆固醇为膜材,中链脂肪酸(MCFAs)为油溶性模型材料,采用薄膜分散- 动态高压微射流法(薄膜分散-DHPM法)及动态高压微射流- 冻融法(DHPM- 冻融法)制备MCFAs 脂质体,以包封率和平均粒径为主要考察指标对两种方法进行比较。结果表明：薄膜分散-DHPM 法最佳制备条件为脂质质量浓度8g/100mL、磷脂与胆固醇质量比5:1、处理压力140MPa、处理次数4 次;DHPM- 冻融法最佳制备条件为冷冻时间0.5h、融化温度40℃、冷冻保护剂为麦芽糖、冷冻保护剂用量3%。最佳条件下,薄膜分散-DHPM 法制备的MCFAs 脂质体平均粒径为87.1nm,分布均匀,包封率可达(66.5 ± 3.1)%;DHPM- 冻融法制备的MCFAs 脂质体粒径较大,平均粒径为110.1nm,包封率较低,为(53.5 ± 4.9)%。通过MCFAs 脂质体泄漏动力学和精密度(日间和日内)实验考察其稳定性。薄膜分散-DHPM 法和DHPM- 冻融法的稳定性都较好,均适合于MCFAs 脂质体的制备。     

Development of chitosan-coated liposomes for sustained delivery of tamarind fruit pulp's extract to the skin

In this study, chitosan-coated liposomes were developed. To entrap lyophilized tamarind extract containing alpha-hydroxy acids (AHAs) together with tartaric acid, the reverse phase evaporation method was used to obtain well-formed liposomes loaded with the extract. The highest entrapment efficiency of 68.3 ± 3.0% into the liposomes was obtained with liposomes consisting of phosphatidylcholine and cholesterol in a molar ratio of 2 : 1 after the extrusion process. The average particle size of the prepared liposomes was 158 ± 26 nm showing a negative zeta potential of −6 mV. For the preparation of the chitosan-coated liposomes, two selected independent parameters were varied: chitosan concentrations of 0.1, 0.5 and 1.0% w/v and volumes of the chitosan solutions of 1, 2 and 3 mL, to study the effects of such parameters on the entrapment efficiency of the extract-loaded liposomes. Variation in the volumes of the chitosan solution did not affect the entrapment efficiency of the liposomes. However, the entrapment efficiency of the AHAs in the chitosan-coated liposomes significantly increased with increasing chitosan concentrations. The size of the chitosan-coated liposomes was in the range of 200–300 nm with a positive zeta potential in the range of 6–29 mV. An in vitro release study using dialysis technique was performed to evaluate the release profile of the tartaric acid from the chitosan-coated liposomes. The obtained results showed the effect of the chitosan-coated liposomes on the lower release rate and on the amount of tartaric acid in comparison with that of the uncoated liposomes. The study in an in vitro skin cell model indicated that the developed system could enhance the potential of tamarind's AHAs on the stimulation of human keratinocyte proliferation being two-fold higher than the solution of the tamarind extract.     

A novel approach to develop β-galactosidase entrapped in liposomes in order to prevent an immediate hydrolysis of lactose in milk

A fractional factorial screening design and a response surface methodology were applied to optimize the entrapment of β-galactosidase in liposomes by dehydration-rehydration vesicle method. The effect of lipid (phosphatidylcholine and cholesterol), enzyme concentration, buffer pH, type and time of sonication, and sucrose concentration were the parameters selected for this study. The cholesterol:phosphatidylcholine (Ch:PC) ratio was the most important factor followed by type of sonicator and enzyme:lipid (E:L) ratio. The buffer pH, sucrose concentration and sonication time did not play an important role in the response. Two of the factors (Ch:PC and E:L ratios) were further studied in a 3² central composite design. The optimized liposomal formulation with an entrapment efficiency of 28% was obtained with Ch:PC and E:L ratios of 0.53 and 13.76, respectively, at pH 6 and employing a probe type sonicator.     

甘氨酸螯合铁脂质体制备及其体外释放的研究

为提高甘氨酸螯合铁的稳定性,采用薄膜-超声法制备了甘氨酸螯合铁脂质体。以包封率为指标,考察了胆固醇、芯材、吐温80的量和水相体积对脂质体的影响,得到了最佳的工艺条件为:胆固醇:芯材:吐温80:大豆卵磷脂=0.2:0.1:0.5:1(wt.:wt.:wt.:wt.),水相体积10mL;最大包封率为63.92%。体外释放结果显示,经过5h,脂质体在模拟胃液和模拟肠液中的释放率分别为24.05%和15.35%;因而,脂质体对芯材甘氨酸螯合铁有较好的保护及缓释效果。     

莪术醇长循环脂质体的制备及体外抗乳腺癌作用研究

目的:制备莪术醇长循环脂质体并对其体外性质进行初步研究。方法:用薄膜分散法制备莪术醇长循环脂质体,对其形态、粒径和电位分布,包封率,体外释放和放置稳定性测定,并考察体外细胞摄取和细胞毒性。结果:制备得到的莪术醇长循环脂质体粒径为(150.3±4.0) nm,PDI为0.197±0.009,zeta电位(-24.5±0.7) mV。莪术醇长循环脂质体平均包封率为80.24%,在4 ℃条件下存放2个月粒径和含药量无明显变化。细胞摄取实验中载香豆素-6长循环脂质体可增强MDA-MB231细胞的摄取。莪术醇长循环脂质体对MDA-MB231细胞具有较强细胞毒性作用,且作用强于莪术醇普通脂质体和游离莪术醇。结论:制备的莪术醇长循环脂质体包封率高,稳定性好,莪术醇长循环脂质体可增强乳腺癌MDA-MB231细胞的摄取及体外细胞毒性。     

柠檬烯脂质体的乙醇注入法制备及其体外释放

为提高柠檬烯稳定性,增加其水溶性,采用乙醇注入法制备了柠檬烯脂质体。以包封率为指标,考察了影响脂质体制备的一些重要的工艺参数,优化了制备柠檬烯脂质体的工艺条件,得到了最佳的工艺条件为:芯材:胆固醇:吐温80:大豆卵磷脂=0.2:0.1:1:10(质量比),醇水体积比1:10,最大包封率为86.6%。体外释放结果显示,经过25h,脂质体在模拟胃液和模拟肠液中的释放率分别为12%和18%;因而,脂质体改善了柠檬烯的水溶性,增加了其稳定性,对柠檬烯有较好的保护及缓释效果,这有利于提高其生物利用率。     

硫酸亚铁脂质体的研制

采用4种不同的方法———薄膜法、超声处理法、逆相蒸发法及冰冻熔融法制备了硫酸亚铁脂质体,通过单因素试验和包封率测定,确定了逆相蒸发法制备硫酸亚铁脂质体的工艺条件,制得的硫酸亚铁脂质体的包封率为67%.作者还初步研究了胆固醇和吐温80的添加量对脂质体物理稳定性的影响,研究结果表明,添加适量的胆固醇和吐温80有助于改善脂质体的物理稳定性.     

Ferrous sulfate liposomes: preparation,stability and application in fluid milk

The effects of cholesterol and Tween 80 on the physical stability of empty liposomes were investigated. Results showed that the physical stability of liposomes, including electrostatic and steric stability, was improved by addition of cholesterol and Tween 80. Liposomes prepared by different methods, thin-film hydration, thin-film sonication, reverse-phase evaporation and freeze-thawing, were tested for their capacity to encapsulate ferrous sulfate. Technology parameters to microencapsulate ferrous sulfate, concentration of ferrous sulfate, hydrating media and sonication strength, were optimized. The concentration of ferrous sulfate and the hydrating medium had a significant effect on the amount of encapsulated ferrous ions. The encapsulation efficiency (EE) of 67% was obtained by using the reverse-phase evaporation method. In milk fortified with ferrous sulfate liposomes, the concentration of iron increased to 15 mg L⁻¹, and it was stable to heat sterilization (100 °C, 30 min) and storage at 4 °C during one week.