顺铂缓释多囊脂质体的制备和体外释放性能研究

目的 制备包封率高和缓释作用好的顺铂缓释多囊脂质体,并与反相蒸发法制备的顺铂普通脂质体比较其体外释药性能。方法 用复乳法制备顺铂多囊脂质体,非火焰原子吸收分光光度法测定顺铂含量,磷脂酶试剂法测定脂质体中磷脂的浓度。测定包封率和体外释药性。结果顺铂多囊脂质体平均粒径为16.6 μm,跨距为1.0。顺铂包封率可高达80%以上。顺铂缓释多囊脂质体的体外释药符合一级释药规律, 释药t_1/2为37.7 h,比反相蒸发法制备的顺铂普通脂质体延长8.4倍。经差示热分析发现辅助膜稳定剂有明显的膜稳定作用。结论顺铂多囊脂质体包封率高,并具有良好的缓释作用。     

卡铂和顺铂在大鼠体内的药动学

应用石墨炉原子吸收法,对国产卡铂和顺铂在大鼠体内的药动学进行了比较。两药的药时过程均可按二室开放模型拟合。卡铂的 T_(1/2β)为14～16h,顺铂为23h。24h 内卡铂经尿排泄90%,顺铂约39%。10mg/kg 顺铂的组织分布及药时曲线下面积分别与60mg/kg 及与30mg/kg 卡铂相近。这些结果与卡铂的肾毒性明显小于顺铂相符合。     

表面不同蛋白对包载顺铂Plu-Chol泡囊理化性质的影响

目的 研究顺铂Plu-Chol泡囊表面结合有不同蛋白时,对其理化性质的影响.方法 用自制Plu-Chol、BSA-Plu或OVA-Plu,制备表面载有蛋白的顺铂Plu-Chol泡囊,并比较泡囊的粒径、包封率、体外释药特性和初步稳定性.结果 当与BSA与Plu为1;50,BSA-Plu与Plu为1;1时,泡囊包封率最好,为75.70%±1.21%,平均粒径738 nm,体外释放符合Weibull distribution模型,t1/2=10 h.结论 表面蛋白的存在对泡囊的形态和粒径影响不大,不同的蛋白质对泡囊的包封牢、体外释放和稳定性有不同影响,蛋白浓度对泡囊包封率有一定影响.     

新型棕榈酰谷氨酸-顺铂纳米粒的制备及其体外药效研究

目的以棕榈酰谷氨酸为载体材料制备新型高载药顺铂纳米粒(palmoyl glutamic acid-cisplatin-nanoparticles,PG-CDDP-NPs),并对其体外抗肿瘤活性进行研究。方法采用肖顿-鲍曼缩合法合成棕榈酰谷氨酸两亲性材料,以所合成的材料为载体,利用其与顺铂的配位作用制备高载药新型顺铂纳米粒,并对所制备的PG-CDDP-NPs性质进行考察;以市售顺铂注射剂为对照,采用MTT法考察了PG-CDDP-NPs对人肝癌细胞HEPG2的体外抗肿瘤活性。结果合成了棕榈酰谷氨酸,并成功制备了高载药量的PG-CDDP-NPs,PG-CDDP-NPs粒径为(106.33±4.45)nm,粒度分布较均匀,包封率为(84.20±0.81)%,载药量质量分数高达(27.03±0.12)%。体外释放研究表明,PG-CDDP-NPs具有缓慢释药性质,24 h累积释放量质量分数仅为(28.74±1.37)%。体外药效学实验结果显示PG-CDDP-NPs和CDDP-S对高表达的人肝癌细胞HEPG2细胞的IC50值分别为3.54μmol·L-1和4.55μmol·L-1。结论以棕榈酰谷氨酸为载体材料可制备高载药量的顺铂纳米粒;PG-CDDP-NPs在体外对HEPG2细胞有杀伤作用,与顺铂注射剂相比,显示出较强的抑瘤效果,PG-CDDP-NPs是一种具有潜在应用价值的顺铂纳米制剂。     

HPLC法测定人血浆中顺铂的浓度及其药动学研究

目的:建立测定非小细胞肺癌患者静脉滴注小剂量顺铂后血浆中药物浓度的方法,并分析其药动学特点。方法:15名非小细胞肺癌化疗患者静脉滴注小剂量顺铂,动态采集患者给药前及末次给药后96h内的血浆样本,以高效液相色谱(HPLC)法测定顺铂的血药浓度,DAS软件计算药动学参数。结果:顺铂血药浓度在0.16～4mg.L-1范围内线性关系良好,相对回收率为96.60%～113.95%,日内、日间RSD均在10%以内。顺铂的药动学模型为开放二室模型,药动学参数分别为:消除半衰期(t1/2β)(62.89±10.84)h,表观分布容积(V)(13.39±4.86)L,清除率(CL)(1.42±0.57)L.h-1,药-时曲线下面积(AUC)(74.24±43.83)mg.h.L-1。结论:HPLC法测定顺铂血药浓度,操作简单易行,重现性好,符合血药浓度监测及人体内药动学研究要求。     

顺铂前药纳米载药系统联合丁硫氨酸亚砜亚胺增强肿瘤化疗效果的研究

目的 合成4种顺铂前药并考察其自组装能力，制备聚乙二醇（PEG）化顺铂前药纳米粒，联合丁硫氨酸亚砜亚胺（BSO）用于肿瘤的共同治疗。方法 以顺铂为原料药，合成4种顺铂前药（C6-Pt、C10-Pt、C12-Pt、C18-Pt）；采用一步纳米沉淀法筛选出自组装能力较强的顺铂前药，制备纳米粒；完成纳米粒的外观形态、稳定性、粒径、Zeta电位及体外药物释放考察；CCK-8法考察顺铂、C12-Pt NPs对MCF-7、B16F10、LLC、4T1的细胞毒性，以B16F10为细胞模型测定BSO的无毒浓度及C12-Pt NPs和BSO联用的最佳摩尔比，考察顺铂、顺铂/BSO、C12-Pt NPs、C12-Pt NPs/BSO对B16F10细胞的生长抑制作用；试剂盒法测定顺铂、顺铂/BSO、C12-Pt NPs、C12-Pt NPs/BSO处理B16F10细胞24 h后的胞内GSH水平。结果 成功合成4种顺铂前药（C6-Pt、C10-Pt、C12-Pt、C18-Pt）；顺铂前药质量浓度为1 mg·mL^-1时，仅有C12-Pt能自组装成为纳米粒（C12-Pt NPs）；C12-Pt NPs粒径分布均匀，具有较好的长期稳定性和血浆稳定性；在含0、1 mmol·L-1 DTT的PBS（pH 7.4）缓冲液中纳米粒释药缓慢，在含10 mmol·L-1 DTT的PBS（pH 7.4）缓冲液中，72 h内药物释放率可达76%；C12-Pt NPs对4种肿瘤细胞的抑制作用强于顺铂；对于B16F10细胞，BSO未表现出明显毒性；当顺铂前药、BSO摩尔比为1∶40时对肿瘤细胞抑制作用最强，表明BSO对顺铂前药具有较好的化疗增敏作用；与顺铂相比，顺铂/BSO、C12-Pt NPs、C12-Pt NPs/BSO处理后B16F10细胞中GSH水平均显著下降（P＜0.001）。结论 C12-Pt NPs制剂学性质良好，C12-Pt NPs对多种肿瘤细胞均具有较强的生长抑制作用，BSO能够有效增强C12-Pt NPs对肿瘤的杀伤效果。     

顺铂明胶微球的研制及相关生物学特性

目的 研制包裹有顺铂的颗粒型可降解性栓塞剂。方法 采用改良的双相乳化冷凝聚合法制备顺铂明胶微球，以原子吸收光谱分析为基础，测定顺铂明胶微球的包裹率、载药率及体外释药特性。结果 顺铂明胶微球颗粒直径均匀，药物包裹率91％。载药率17.4%，体外4b内缓释96％。结论 本法制得的顺铂明胶微球性质稳定，微球降解速率及药物释放速度基本符合临床要求。     

盐酸曲马多胃漂浮缓释胶囊的制备

目的 制备盐酸曲马多胃漂浮缓释胶囊(THIFSC),并研究其体外释药、持浮力随时间变化的情况.方法 以正交设计优选处方,采用自制浮力测定仪测定THIFSC的持浮力在体外的变化,体外释药采用转篮法.结果 所制THIFSC的体外释药符合Higuchi模型,体外至少可漂浮48 h,漂浮6～55 h时,净浮力几乎线性下降.结论 所制备的THIFSC在体外持浮性能良好,释药行为具明显缓释特征.     

多单元口崩脉冲控释片的研制.Ⅲ.盐酸地尔硫(卓)脉冲小丸口崩片的释药机制及其初步体内评价

测定了3批盐酸地尔硫(卓)脉冲控释小丸口崩片的体外药物释放曲线,并采用不同的数学模型进行拟合,探讨其释药机制.结果表明,本品在4h内的累积释放率低于10％,0～24h的体外释放度用零级模型拟合效果较好,5～24h的体外释放度用Higuchi模型拟合效果较好.并考察其与市售控释胶囊(Herbesser,参比制剂)在6名健康志愿者体内的药动学.结果表明,与参比制剂相比,本品在体内的释药较参比制剂推迟4～5 h,达到了预设的脉冲和控释效果.用Loo-Riegelman法计算本品体内吸收率,并与相应时间的体外释放数据进行线性回归,所得方程的相关系数为0.997 0,提示其体内外具有显著的相关性.     

中晚期胃肠癌患者腹股沟淋巴结灌注顺铂化疗药代动力学研究

应用原子吸收光谱法测定血药浓度，对10例中晚期胃肠癌患者经腹股沟结灌注顺铂的药代动力学进行初步研究。结果显示总铂在血浆中的药代动力学模式为二室模型。经淋巴结途径给药后血浆总铂浓度迅速升高，在15～20min之内达到峰值，随即缓慢消除下降。血浆分布半衰期（t1／2a）为0.185h，血浆消除半衰期（t1／2β）为6.944h，提示从腹腔沟淋巴结途径给药肿瘤组织可较多摄取顺铂。     

Oxaliplatin-induced damage of cellular DNA

Damage to cellular DNA is believed to determine the antiproliferative properties of platinum (Pt) drugs. This study characterized DNA damage by oxaliplatin, a diaminocyclohexane Pt drug with clinical antitumor activity. Compared with cisplatin, oxaliplatin formed significantly fewer Pt-DNA adducts (e.g., 0.86+/-0.04 versus 1.36+/- 0.01 adducts/10(6) base pairs/10 microM drug/1 h, respectively, in CEM cells, P<.01). Oxaliplatin was found to induce potentially lethal bifunctional lesions, such as interstrand DNA cross-links (ISC) and DNA-protein cross-links (DPC) in CEM cells. As with total adducts, however, oxaliplatin produced fewer (P<.05) bifunctional lesions than did cisplatin: 0.7+/-0.2 and 1.8+/-0.3 ISC and 0.8+/-0.1 and 1.5+/-0.3 DPC/10(6) base pairs/10 microM drug, respectively, after a 4-h treatment. Extended postincubation (up to 12 h) did not compensate the lower DPC and ISC levels by oxaliplatin. ISC and DPC determinations in isolated CEM nuclei unequivocally verified that oxaliplatin is inherently less able than cisplatin to form these lesions. Reactivation of drug-treated plasmids, observed in four cell lines, suggests that oxaliplatin adducts are repaired with similar kinetics as cisplatin adducts. Oxaliplatin, however, was more efficient than cisplatin per equal number of DNA adducts in inhibiting DNA chain elongation ( approximately 7-fold in CEM cells). Despite lower DNA reactivity, oxaliplatin exhibited similar or greater cytotoxicity in several other human tumor cell lines (50% growth inhibition in CEM cells at 1.1/1.2 microM, respectively). The results demonstrate that oxaliplatin-induced DNA lesions, including ISC and DPC, are likely to contribute to the drug's biological properties. However, oxaliplatin requires fewer DNA lesions than does cisplatin to achieve cell growth inhibition.     

纳米碳用于早期乳腺癌前哨淋巴结活检的可行性研究

目的 探讨纳米碳用于早期乳腺癌前哨淋巴结活检的可行性及最佳使用方法.方法 使用纳米碳对36例早期乳腺癌患者进行前哨淋巴结活检并确定纳米碳使用最佳条件.选择141例早期乳腺癌分别采用纳米碳(83例)和美兰(58例)进行前哨淋巴结活检,比较两种方法检测效果.结果 纳米碳最佳使用剂量和时间是1 ml和术前10～15 min.纳米碳组和美兰组前哨淋巴结的检出率、准确率、假阴性率分别为100.0％、96.4％、11.1％和88.0％、94.1％、15.8％.纳米碳组具有较高的检出率和较低的假阴性率.结论 纳米碳作为示踪剂进行乳腺癌前哨淋巴结活检是可行的,采用纳米碳作为示踪剂的前哨淋巴结检出率高.     

Resiniferatoxin antagonizes cisplatin-induced emesis in dogs and ferrets

We evaluated the antiemetic activity of resiniferatoxin, an ultrapotent capsaicin analogue, on cisplatin- and apomorphine-induced emesis in dogs, and on cisplatin-induced acute and delayed emesis in ferrets. In the dog, resiniferatoxin (10 microg/kg, s.c.) 30 min before the injection of cisplatin markedly prevented acute emesis induced by cisplatin. When animals were given resiniferatoxin (10 microg/kg, s.c.) 24 h prior to cisplatin, the emesis was still inhibited, but not significantly. Resiniferatoxin (10 microg/kg, s.c.) 30 min before the administration of apomorphine also significantly reduced the emetic responses induced by apomorphine in dogs. In the ferret, resiniferatoxin (10 microg/kg, s.c.) 30 min prior to cisplatin completely inhibited acute emesis caused by cisplatin (10 mg/kg, i.p.). When ferrets were given resiniferatoxin (10 microg/kg, s.c.) 16 h prior to cisplatin, the emesis was still significantly inhibited. Cisplatin (5 mg/kg, i.p.) induced both acute (0-24 h) and delayed (24-72 h) phase emesis, and a single injection of resiniferatoxin (10 microg/kg, s.c.) at 36 h after cisplatin significantly reduced subsequent emetic responses during the 36-72 h period. These results suggest that resiniferatoxin-related vanilloids may be useful drugs against both acute and delayed emesis induced by cancer chemotherapy.     

Preparation and release kinetics of microencapsulated cisplatin with ethylcellulose

Several kinds of microcapsules containing cisplatin were prepared by the ethylcellulose coacervation process in an attempt to administer cisplatin with chemoembolization. Microcapsules made either with mechanical stirring or with sonication showed similar properties; the chemical structure of cisplatin was not affected by the micro-encapsulation process. The release kinetics of cisplatin from ethylcellulose-walled microcapsules followed different patterns, according to the wall thickness. In each case, the release kinetics did not depend on the stirring rate of the surrounding medium. Only microcapsules with a cisplatin release ratio from 80 to 100% within 24 h were selected for later clinical use.     

Role of NK1 receptors on cisplatin-induced nephrotoxicity in the rat

The role of NK1 receptors on the nephrotoxicity associated with cisplatin treatment was evaluated. Adult Sprague-Dawley male rats (300-400 g) were treated with saline (0.1 ml/100 g, i.p., every 8 h for 72 h) or the selective NK1 receptor antagonist (GR205171; 2 mg/kg, i.p., every 8 h for 72 h). Treatments were started 5 min before cisplatin (7.5 mg/kg, i.p., single dose). All evaluations were made from 72 h to 96 h after cisplatin. An oral load of 10 ml/kg of water was given at time 0 (72 h after cisplatin). Cisplatin reduced the urinary volume (-45%), creatinine clearance (>90%), lithium clearance (-76%) and urinary potassium excretion (-54%). Protein and sodium excretion was not affected by cisplatin. GR205171 prevented the reduction in urine volume induced by cisplatin. In addition, the decreases in creatinine and lithium clearances induced by cisplatin were also attenuated by the NK1 receptor antagonist. The clearance of creatinine averaged 0.57+/-0.2 ml/min in controls, 0.004+/-0.01 ml/min after cisplatin, and 0.09+/-0.02 ml/min after cisplatin + GR205171. The lithium clearance was 0.09+/-0.04 ml/min in controls, 0.02+/-0.01 ml/min after cisplatin and 0.06+/-0.01 ml/min after cisplatin + GR205171. Cisplatin induced marked necrosis, vacuolation and edema of proximal renal tubules; these changes were considerably reduced in GR205171-treated animals. These results indicate that treatment with a selective NK1 receptor antagonist ameliorated cisplatin-induced renal toxicity in rats, as evidenced by improvements in renal function and histology.     

顺铂对人肺腺癌细胞作用与ERCC1、Bcl-2表达的相关性研究

目的:探讨ERCC1、Bcl-2表达与顺铂作用的关系,进而推测ERCC1、Bcl-2在顺铂耐药中的作用.方法:选择人肺腺癌细胞A549及其耐DDP细胞株A549/DDP作为研究对象,采用MTT法检测A549/DDP细胞耐药指数;免疫细胞化学方法、RT-PCR方法检测不同浓度、不同作用时间干预后细胞中ERCC1、Bcl-2的表达.结果:10μg/mL DDP作用12 h,A549细胞中ER-CC1、Bcl-2 mRNA表达开始增高,随着作用时间的延长,ERCC1、Bcl-2 mRNA的表达逐渐增高,在72 h表达最强.浓度为5μg/mL的DDP即可刺激A549细胞中ERCC1、Bcl-2 mRNA表达水平上升,随着DDP浓度的增加,其表达水平逐渐上升,ERCC1民mRNA表达水平在20μg/mL组达到高峰.与亲本细胞相比,A549/DDP中ERCC1、Bcl-2表达明显增高.结论:随着顺铂作用时间的延长和浓度的增加,A549细胞中ERCC1、Bcl-2 mRNA和蛋白的表达量增加,推测ERCC1、Bcl-2可能参与了顺铂继发耐药的形成.     

Oxaliplatin degradation in the presence of important biological sulphur-containing compounds and plasma ultrafiltrate.

Oxaliplatin undergoes extensive non-enzymatic chemical transformation in the body. Complexes with sulphur-containing compounds have previously been found in plasma from patients treated with oxaliplatin. We have studied the kinetics for the reactions between oxaliplatin and cysteine, methionine, and glutathione, by determination of the degradation of oxaliplatin using liquid chromatography with UV-detection. We also studied the degradation of oxaliplatin in plasma ultrafiltrate (PUF). For the degradation of oxaliplatin in the presence of glutathione, methionine, and cysteine, the second-order rate constants were 4.7M(-1)min(-1) (95% confidence interval [C.I.], 4.4-5.0M(-1)min(-1)), 5.5M(-1)min(-1) (95% C.I., 5.2-5.7M(-1)min(-1)), and 15M(-1)min(-1) (95% C.I., 14-17M(-1)min(-1)), respectively. The reaction rate was much faster than previously reported kinetics for cisplatin. The degradation rate of oxaliplatin in PUF was biphasic. The rate constant for the first phase varied from 9.5x10(-3) to 0.13min(-1) and for the second phase from (1.7 to 1.8)x10(-3)min(-1) in PUF from five healthy volunteers. The first hours of the degradation of oxaliplatin in PUF are accounted for by the degradation of oxaliplatin in a cocktail of sodium chloride and sulphur-containing compounds at physiological plasma concentrations. In conclusion, the rate of the reaction of oxaliplatin with three sulphur-containing compounds was faster for oxaliplatin than what is previously known for cisplatin. This may be important with respect to differences in the cellular effects of cisplatin and oxaliplatin treatment.     

Nanotechnology in oncology: Characterization and in vitro release kinetics of cisplatin-loaded albumin nanoparticles: Implications in anticancer drug delivery

Context:

Nanotechnology is an empowering technology that holds promise in cancer therapeutics by increasing the ratio of tumor control probability to normal tissue complication probability. It can increase the bioavailability of the drug at the target site, reduce the frequency of administration and reach otherwise lesser-accessible sites. The present study shows the feasibility of the cisplatin-loaded albumin nanoparticle as a sustained delivery system.

Aims:

Cisplatin is one of the most widely used chemotherapeutic agents for the treatment of malignant disorders. Conventional cisplatin formulation given as intravenous infusion has low bioavailability to the target organ in addition to significant side-effects, like ototoxicity and nephrotoxicity. The aim of this study was to develop a protein-based nanoparticulate system for sustained release of cisplatin.

Materials and Methods:

Nanoparticles were prepared by the coacervaton method of microcapsulation and chemical cross-linking with glutaraldehyde. Particle size was characterized by dynamic light scattering and transmission electron microscopy.

Results and Conclusions:

Using the coacervation method, nanoparticles of less than 70 nm diameter were produced. Drug encapsulation measured by ultraviolet spectroscopy varied from 30% to 80% for different ratios of cisplatin and protein. In vitro release kinetics shows that the nanoparticle-based formulation has biphasic release kinetics and is capable of sustained release compared with the free drug (80% release in 45 h). The study proves the feasibility of the albumin-based cisplatin nanoparticle formulation as a sustained release vehicle of cisplatin.     

Protective effects of vitamin E and C on cisplatin nephrotoxicity in developing rats

The kinetics of vitamin E was followed in serum, liver and kidney of 10- and 55-day-old rats after the administration of a single i.m. dose of 100 mg α-tocopherol acetate/100 g body wt. The basal levels without vitamin E administration were significantly higher in serum and liver of 10- than 55-day-old rats. The effect of vitamin E on cisplatin (CP; 0.6 mg/100 g body wt., i.p.) nephrotoxicity was investigated by determining urinary volume and protein excretion, as well as the concentration of blood urea nitrogen (BUN) and lipid peroxides in renal tissue (LPO). Previously described age differences in CP nephrotoxicity were confirmed. The administration of vitamin E, 12 h prior to CP, diminished the toxic effect of CP in young and adult rats. This effect could not be enhanced by a second administration of vitamin E. The simultaneous administration of vitamin E and C 12 h prior to CP intensified the protective effect of a single administration of vitamin E in 10- and 55-day-old rats without influencing the concentration of platinum in renal tissue. Received: 10 April 1997 / Accepted: 10 June 1997     

Kinetic study on the reaction of cisplatin with metallothionein.

The binding of cisplatin to metallothionein (MT) was investigated at 37 degrees C in 10 mM Tris-NO3 (pH approximately 7.4) and 4.62 mM NaCl. The conditions were chosen to mimic passage of clinical concentrations of cisplatin through the cytosol. The reactions were monitored by high-performance liquid chromatography (HPLC), atomic absorption spectroscopy, and ultraviolet (UV) absorption spectroscopy. The UV data showed that several reactions occur, the first of which does not affect the absorbance (no Pt-sulfur bond formation). They also suggested that if [cisplatin] is large compared with [MT], the rate of subsequent reaction is between first and second order in [cisplatin] and between zeroth and first order in [MT]. HPLC eluates with 24 < retention time (tR) < 27 min contained undialyzable Pt, which increased with reaction time and corresponded to Pt-thionein product. Eluates with 3 < tR < 7 min corresponded to unbound cisplatin and allowed determination of second-order rate constants (k), using the second-order rate equation. The k value for cisplatin reacting with apo-MT was approximately 0.14 M-1 s-1, Cd/Zn-MT approximately 0.75 M-1 s-1, Cd7-MT approximately 0.53 M-1 s-1, and Zn7-MT approximately 0.65 M-1 s-1. Thus, cisplatin displaced Cd and Zn equally well. Leukocyte MT concentration was approximately 1.0 mM, so that the kinetics of cisplatin binding to cellular MT is pseudo-first order (pseudo-first-order rate constant, approximately 0.63 x 10-3 s-1; half-life, approximately 18 min). With [cisplatin] = 10 microM, the rate of cisplatin reaction with MT is approximately 6.3 micromol s-1 cm-3. We conclude that cellular MT can trap significant amounts of cisplatin and may efficiently contribute to cisplatin resistance.