羟基喜树碱两亲性长循环纳米粒的药动学研究

 目的 制备羟基喜树碱的两亲性长循环纳米粒并进行初步的理化性质考察,研究了其在大鼠体内的药动学。方法 本实验合成了聚乙二醇-聚己内酯嵌段共聚物(PEG-PCL),并以此为载体材料,采用溶剂扩散法制备了羟基喜树碱两亲性长循环纳米粒（HCPT-PEG-PCL-NPs),对其进行初步的质量评价及稳定性考察,高效液相色谱法检测并比较了HCPT注射液和不同共聚物载体制备的羟基喜树碱两亲性长循环纳米粒在大鼠体内的药动学参数。结果 以共聚物PEG4000-PCL1250、PEG4000-PCL2000、PEG2000-PCL1250、PEG2000-PCL2000为载体制备的4种羟基喜树碱两亲性长循环纳米粒的平均粒径依次为110.0、116.1、99.1、119.9 nm,平均ξ电位依次为-16.9、-22.4、-28.8、-33.5mV,平均包封率依次为83.10%、88.29%、77.46%、80.67%,平均载药量依次为2.56%、2.96%、2.14%、2.31%;冻干粉剂的稳定性较好,但高温环境不利于保存。HCPT注射液t_1/2为0.141 8 h,以共聚物载体PEG4000-PCL1250、PEG4000-PCL2000、PEG2000-PCL1250、PEG2000- PCL2000制备的羟基喜树碱两亲性长循环纳米粒的t_1/2依次为它的18.07、9.08、5.25、5.14倍。结论 羟基喜树碱两亲性长循环纳米粒在体内有较好的长循环作用。     

Preliminary evaluation of particle systems visualization on the skin surface by scanning electron microscopy and transparency profilometry

Background: There is a rising debate concerning the possible side effects arising from the use of particles at nanosize since the production of nanomaterials is increasing worldwide. Nanoparticles are able to enter the body through the skin, lungs or intestinal tract, depositing in several organs, and the risk associated with exposure to them, the routes of entry and the molecular mechanisms of any cytotoxicity need to be well understood. The aim of this work was to evaluate the suitability of skin replica as a method to study the colloidal systems visualization and distribution on skin surface. Methods: Solid lipid nanoparticles (SLN) were used as carrier systems. Skin replicas on healthy volunteers, before and after SLN application, were prepared and visualized using profilometry and scanning electron microscopy (SEM). Results: The results obtained in our study show that skin replica represents a suitable method to study the colloidal systems and their interaction with the skin surface. Conclusion: Profilometry enabled us to observe the systems distribution on a cutaneous texture. In addition, SEM, thanks to its high magnifications and field depth, allowed us to evaluate particles' distribution on the skin texture and the interaction between particles of different compositions and replica silicone.     

Silver-109/Silver/Gold Nanoparticle-Enhanced Target Surface-Assisted Laser Desorption/Ionisation Mass Spectrometry—The New Methods for an Assessment of Mycotoxin Concentration on Building Materials

This study aimed to detect and quantify mycotoxins on building materials using innovative laser mass spectroscopy methods—silver-109/silver/gold nanoparticle-enhanced target surface-assisted laser desorption/ionisation mass spectrometry (¹⁰⁹AgNPs, AgNPs and AuNPs SALDI). Results from SALDI-type methods were also compared with commonly used matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. Standards of seven moulds mycotoxin in a final concentration of 100 µg/mL for patulin, citrinin, 3-nitropropionic acid, alternariol and 20 µg/mL for sterigmatocystin, cyclopiazonic acid, roquefortine C in the mixture were tested in pure solutions and after extraction from the plasterboards. Among the studied SALDI-type method, the lowest detection limits and the highest signal intensity of the mycotoxins tested were obtained with the use of ¹⁰⁹AgNPs SALDI MS. The ¹⁰⁹AgNPs method may be considered as an alternative to the currently most frequently used method MALDI MS and also liquid chromatography tandem mass spectrometry LC-MS/MS for mycotoxin determination. Future studies should attempt to use these methods for mass spectrometry imaging (MSI) to evaluate spatial distribution and depth of mycotoxin penetration into building materials.     

Effect of Zinc Supplementation on the Serum Metabolites Profile at the Early Stage of Breast Cancer in Rats

The cytotoxic properties of zinc nanoparticles have been evaluated in vitro against several types of cancer. However, there is a lack of significant evidence of their activity in vivo, and a potential therapeutic application remains limited. Herein we report the effective inhibition of tumor growth by zinc nanoparticles in vivo, as the effect of the dietary intervention, after the chemical induction in a rodent model of breast cancer. Biopsy images indicated grade 1 tumors with multiple inflammatory infiltrates in the group treated with zinc nanoparticles, whereas, in the other groups, a moderately differentiated grade 2 adenocarcinoma was identified. Moreover, after the supplementation with zinc nanoparticles, the levels of several metabolites associated with cancer metabolism, important to its survival, were found to have been altered. We also revealed that the biological activity of zinc in vivo depends on the size of applied particles, as the treatment with zinc microparticles has not had much effect on cancer progression.     

Combined Poly(isobutylcyanoacrylate) and Cyclodextrins Nanoparticles for Enhancing the Encapsulation of Lipophilic Drugs

Purpose. The aim of this study was to prepare and characterize nanoparticulate systems constituted of poly(isobutylcyanoacrylate) and cyclodextrins and intended for increasing the loading of the particles with lipophilic substances. Progesterone was used as a model substance. Methods. Nanoparticles were prepared by polymerization of isobutyl-cyanoacrylate in presence of cyclodextrins or progesterone/ hydroxy-propyl--cyclodextrin complex. Particle size, zeta potential, cyclodextrin and progesterone loading of the particles were determined. Results. Nanoparticles could be easily prepared in presence of cyclodextrins. An increase in hydroxypropyl--cyclodextrin concentration resulted in small nanoparticles (less than 50 nm). It was found that large amounts of cyclodextrins remained associated to the particles, resulting in a 50 fold increase in progesterone loading compared to nanoparticles prepared in absence of cyclodextrins. Conclusions. The poly(isobutylcyanoacrylate)—cyclodextrin nanoparticles were characterized by the presence of many lipophilic sites belonging to the cyclodextrins which were firmly anchored to the structure of the particles. Therefore, this new type of nanoparticles offers probably an opportunity for increasing the loading of nanoparticles with various lipophilic drugs.     

壳聚糖纳米粒在基因治疗中的应用

壳聚糖是自然界存在的唯一的碱性多糖，具有良好的生物粘附性、生物可降解性及生物相容性。用壳聚糖制备的纳米粒具有助渗作用及生物粘附性，在基因递送载体的研究中具有广阔的发展前景。     

麦胚凝集素修饰的EGCG-明胶-壳聚糖纳米粒的制备、表征及体外抗肿瘤活性研究

目的?制备麦胚凝集素（WGA）修饰的表没食子儿茶素没食子酸酯（EGCG）-明胶(Gel)-壳聚糖(Cs)纳米粒,研究其对结肠癌HT-29细胞的作用。方法?以明胶及壳聚糖为载体辅料,采用静电自组装的方法制备EGCG-Gel-Cs纳米粒,以包封率为指标,通过Box-Behnken设计-效应面法（BBD-RSM）优化纳米粒的制备处方及工艺,再将经戊二醛活化的WGA修饰到纳米粒表面。采用差示扫描量热分析药物在纳米粒中的存在状态,采用细胞毒性及细胞凋亡实验,比较研究纳米粒与原料药的体外抗肿瘤活性。结果?EGCG-Gel-Cs纳米粒的最优处方:Gel与Cs的质量比为4.2,Gel与EGCG的质量比为2.82,反应温度为34℃,包封率为(74.42±0.074)%。EGCG-Gel-Cs纳米粒粒径为(264.13±6.48)nm,经过修饰后纳米粒粒径为(389.70±9.00)nm。WGA-EGCG-Gel-Cs纳米粒对HT-29细胞的细胞毒性和细胞凋亡率显著高于EGCG原料药。结论?WGA-EGCG-Gel-Cs纳米粒可显著提高细胞毒性作用。      

Evaluation of In Vivo toxicity of Novel Biosurfactant from Candida parapsilosis loaded in PLA-PEG Polymeric Nanoparticles

The aim of this study was to evaluate the toxicological profile of biosurfactant encapsulated polymeric nanoparticles of Polylactic acid-Polyethylene glycol (PLA-PEG) in mice. Hematological, biochemical and histopathological samples of rodents were evaluated. Mice were selected randomly and divided into 3 treatment groups and one control group. Group I mice served as a control group, Group II were administrated with biosurfactant, Group III were treated with Polymeric nanoparticles of PLA-PEG. Group IV mice were injected with biosurfactant loaded polymeric nanoparticles of PLA-PEG. The formulations were administered intravenously via tail vein with 20 μg/mL dose concentration of biosurfactant. The normal control group was injected with only PBS. Blood samples were collected on 7th, 14th and 21st day and hematological and biochemical assays were performed. After the blood collection, mice were sacrificed for histopathological examination. The results showed that there were no significant difference in hematology parameter between the control and treated group. Some minute, non-significant changes were found in biochemical parameters which were not considered. Histopathological result of selected vital organs revealed that the biosurfactant and/or PLA-PEG polymeric nanoparticles can be considered as safe as no toxicological features were observed in histopathology of tissues. Hence, it can be deliberated that the biosurfactant encapsulated in PLA-PEG copolymeric nanoparticles are non toxic and can provide a safe, suitable platform for biomedical applications in future.