Drug self-assembly: A phenomenon at the nanometer scale with major impact in the structure–biological properties relationship and the treatment of disease

Under water-rich conditions, small amphiphilic and hydrophobic drug molecules self-assemble into supramolecular nanostructures. Thus, substantial modifications in their interaction with cellular structures and the ability to reach intracellular targets could happen. Additionally, drug aggregates could be more toxic than the non-aggregated counterparts, or vice versa. Moreover, since self-aggregation reduces the number of effective “monomeric” molecules that interact with the target, the drug potency could be underestimated. In other cases, the activity could be ascribed to the non-aggregated molecule while it stems from its aggregates. Thus, drug self-assembly could mislead from drug throughput screening assays to advanced preclinical and clinical trials. Finally, aggregates could serve as crystallization nuclei. The impact that this phenomenon has on the biological performance of active compounds, the inconsistent and often controversial nature of the published data and the need for recommendations/guidelines as preamble of more harmonized research protocols to characterize drug self-aggregation were main motivations for this review. First, the key molecular and environmental parameters governing drug self-aggregation, the main drug families for which this phenomenon and the methods used for its characterization are described. Then, promising nanotechnology platforms investigated to prevent/control it towards a more efficient drug development process are briefly discussed.     

Development,optimization, and characterization of a novel tea tree oil nanogel using response surface methodology

Purpose: To develop and optimize nanoemulsion (NE)-based emulgel (EG) formulation as a potential vehicle for topical delivery of tea tree oil (TTO).

Methodology: Central composite design was adopted for optimizing the processing conditions for NE preparation by high energy emulsification method viz. surfactant concentration, co-surfactant concentration, and stirring speed. The optimized NE was developed into emulgel (EG) using pH sensitive polymer Carbopol 940 and triethanolamine as alkalizer. The prepared EG was evaluated for its pH, viscosity, and texture parameters, ex vivo permeation at 37?°C and stability. Antimicrobial evaluation of EG in comparison to conventional gel and pure TTO was also carried out against selected microbial strains.

Results and discussion: Optimized NE had particle size and zeta potential of 16.23?±?0.411?nm and 36.11?±?1.234?mV, respectively. TEM analysis revealed the spherical shape of droplets. The pH of EG (5.57?±?0.05?) was found to be in accordance with the range of human skin pH. EG also illustrated efficient permeation (79.58?μL/cm²) and flux value (J_SS) of 7.96?μL cm²/h through skin in 10?h. Viscosity and texture parameters, firmness (9.3?±?0.08?g), spreadability (2.26?±?0.06?mJ), extrudability (61.6?±?0.05?mJ), and adhesiveness (8.66?±?0.08?g) depict its suitability for topical application. Antimicrobial evaluation of EG with same amount of TTO as conventional gel revealed broader zones of growth inhibitions against all the selected microbial strains. Moreover, EG was also found to be nonirritant (PII 0.0833). These parameters were consistent over 90 d.

Conclusion: TTO EG turned out to be a promising vehicle for the topical delivery of TTO with enhanced therapeutic efficacy.     

大分子乳化剂稳定的纳米乳中β-胡萝卜素的降解

分别以乳清分离蛋白、热处理乳清分离蛋白、乳清分离蛋白与麦芽糖糊精的混合物和美拉德反应复合物为乳化剂,制备β-胡萝卜素纳米乳,并考察其乳滴粒径分布及β-胡萝卜素的降解。结果表明：乳清分离蛋白与麦芽糖糊精共价复合后,形成的纳米乳液平均粒径更小,但复合物加速纳米乳中β-胡萝卜素的降解。而热处理乳清分离蛋白能显著抑制纳米乳中β-胡萝卜素的降解,其机制可能是蛋白质大分子聚集体的形成对β-胡萝卜素起保护作用。     

Curcumin loaded fish scale collagen-HPMC nanogel for wound healing application: Ex-vivo and In-vivo evaluation

The objective of the present investigation was to formulate curcumin loaded fish scale collagen (FSC)-hydroxypropyl methyl cellulose (HPMC K100) nanogel (CNG) for wound healing application. The curcumin nanoemulsion was prepared, characterized and loaded in FSC-HPMC nanogel. The nanogel was evaluated for ex-vivo permeation, in-vivo, skin irritation, and stability study. Ex-vivo permeation study demonstrated that CNG prolonged release and exhibited higher percent contraction value of wound compared to other formulations. In skin irritation study, formulation produced the score of less than 2 compared to control. It concluded that curcumin loaded FSC-HPMC nanogel could be prepared for wound healing applications.     

Fabrication of Food Grade Vitamin E Nanoemulsion by Low Energy Approach,Characterization and Its Application

The present study was carried out to fabricate the food grade vitamin E acetate nanoemulsion using edible mustard oil and to evaluate its improved bioactivities. A food-grade vitamin E acetate nanoemulsion was fabricated using the edible mustard oil and surfactant Tween-80. Flocculation was not observed for 15 days. The nanoemulsion was characterized for droplet morphology and size distribution using atomic force microscope and zetasizer, respectively. We observe a stable nanoemulsion of spherical morphology and a size distribution of 86.45 ± 3.61 nm. Further, the high-performance liquid chromatography method was used to determine the vitamin E acetate concentration and encapsulation efficiency for the stable nanoemulsion. These nanoemulsions showed improved bioactivity, antioxidant, and antimicrobial activity and could be potentially used to increase the shelf life of fruit juice.     

基于微纳米气泡强化的槽式超声反应器制备纳米乳液

为开发工业制备纳米乳液新技术,通过仿真实验分析在槽式超声反应器中引入微纳米气泡对声场强度和分布的影响。以花生油为油相,吐温80和司盘80为乳化剂,在乳化过程中采用基于微纳米气泡强化的槽式超声反应器制备纳米乳液。利用正交实验探索了超声时间、进气量、复合乳化剂添加量对纳米乳液平均粒径与多分散指数的影响,并优化了纳米乳液制备条件。结果表明：加入适量微纳米气泡会提高声场强度和分布均匀性;制备纳米乳液的最优条件为超声时间12 min、进气量150 mL/min、复合乳化剂添加量3%(以水的体积计),在此条件下乳液平均粒径为190.9 nm,多分散指数为0.178,较未加入微纳米气泡所制备乳液的平均粒径减小73.3%,且表现出更好的动力学稳定性。该方法制备的纳米乳液平均粒径和多分散指数均较小,且具有快速、体量大、成本低的生产优势。     

黄芩甙纳米乳的制备

研制了黄芩甙纳米乳并对其进行了质量评价。通过绘制伪三元相图优选处方,以肉豆蔻酸异丙酯(IPM)、液体石蜡和维生素E油为油相,蓖麻油聚氧乙烯醚(EL-40)为表面活性剂,乙醇为助表面活性剂制备黄芩甙纳米乳,用透射电子显微镜(TEM)、Nicomp388/ZetaPALS激光粒度测定仪分别考察了其形态和粒径;通过恒温加速实验检验了其稳定性。黄芩甙纳米乳在透射电镜下呈圆球形,分布均匀,平均粒径为(35.3±0.27)nm,恒温加速实验结果显示其未分层,仍为澄清透明纳米乳状液。纳米乳质量稳定,能提高黄芩甙的溶解度,且有很好的皮肤渗透性,提高了化妆品在皮肤上的延展性,可望用作皮肤化妆品基质。     

胡柚精油纳米乳的制备及品质评价

研制了胡柚精油纳米乳并对其进行了品质评价。利用伪三元相图法优选配方,直接以胡柚精油为油相,从Span系列和Tween系列中筛选出Span-80与Tween-80作为混合表面活性剂,选用丙三醇为助表面活性剂,加入蒸馏水制备胡柚精油纳米乳。通过染色法鉴定染色法该乳液属于O/W型,清澈透明有明显的丁达尔现象,经激光粒度仪测得分散相平均粒径为21 nm,且粒径大小集中,影响因素实验表明该胡柚精油纳米乳有良好的稳定性。     

天然抗菌剂纳米乳液的制备、抑菌机理及在肉类保鲜中的应用研究进展

肉类富含蛋白质、脂肪等营养物质,在加工或贮藏过程中易受到微生物的污染而发生腐败变质。天然抗菌剂作为一种肉类保鲜剂,因具有良好的抑菌活性、安全性及生物可降解性而受到广泛关注。然而,有些天然抗菌剂具有高挥发性、低水溶性、热不稳定等缺陷,导致其在肉类保鲜中的应用受到局限。纳米乳液作为一种包埋系统,能够将天然抗菌剂包埋在其内部,以提高天然抗菌剂的稳定性和抑菌活性,并改善天然抗菌剂的释放性能,从而缓解天然抗菌剂的局限性。本文综述天然抗菌剂纳米乳液的构成和制备方法,并在此基础上进一步论述天然抗菌剂纳米乳液的抑菌机理与优势以及天然抗菌剂纳米乳液在肉类保鲜中的研究进展,以期为天然抗菌剂纳米乳液在肉类保鲜中的应用提供理论基础和实践指导。