Biodegradable Porous Microneedles for an Electric Skin Patch

An array of porous microneedles (PMNs) made of biodegradable poly(lactic-co-glycolic acid) (PLGA) is fabricated by a combination of molding and freeze-drying methods. The optimized mixture of PLGA and 1,4-dioxane is poured into a mold of a microneedle array, followed by the freezing and sublimation of the frozen particles of 1,4-dioxane, a procedure that left an interconnecting porous structure in the PLGA with a porosity around 50%. The mechanical strength of the PMN made of PLGA (PLGA-PMN) is reinforced by modification with carboxymethylcellulose (CMC), resulting in sufficient strength enough for insertion into an excised porcine skin. The transdermal resistance is significantly decreased by the CMC-modified PLGA-PMN, which would improve the efficiency and safety of DC current-based transdermal techniques, including the electrical monitoring of the skin condition and iontophoresis for drug delivery and medical diagnosis.     

N-Palmitoyl Serinol Stimulates Ceramide Production through a CB1-Dependent Mechanism in In Vitro Model of Skin Inflammation

Ceramides, a class of sphingolipids containing a backbone of sphingoid base, are the most important and effective structural component for the formation of the epidermal permeability barrier. While ceramides comprise approximately 50% of the epidermal lipid content by mass, the content is substantially decreased in certain inflammatory skin diseases, such as atopic dermatitis (AD), causing improper barrier function. It is widely accepted that the endocannabinoid system (ECS) can modulate a number of biological responses in the central nerve system, prior studies revealed that activation of endocannabinoid receptor CB1, a key component of ECS, triggers the generation of ceramides that mediate neuronal cell fate. However, as the impact of ECS on the production of epidermal ceramide has not been studied, we here investigated whether the ECS stimulates the generation of epidermal ceramides in an IL-4-treated in vitro model of skin inflammation using N-palmitoyl serinol (PS), an analog of the endocannabinoid N-palmitoyl ethanolamine. Accordingly, an IL-4-mediated decrease in cellular ceramide levels was significantly stimulated in human epidermal keratinocytes (KC) following PS treatment through both de novo ceramide synthesis- and sphingomyelin hydrolysis-pathways. Importantly, PS selectively increases ceramides with long-chain fatty acids (FAs) (C22–C24), which mainly account for the formation of the epidermal barrier, through activation of ceramide synthase (CerS) 2 and Cer3 in IL-4-mediated inflamed KC. Furthermore, blockade of cannabinoid receptor CB1 activation by AM-251 failed to stimulate the production of total ceramide as well as long-chain ceramides in response to PS. These studies demonstrate that an analog of endocannabinoid, PS, stimulates the generation of specific ceramide species as well as the total amount of ceramides via the endocannabinoid receptor CB1-dependent mechanism, thereby resulting in the enhancement of epidermal permeability barrier function.     

Resveratrol-Induced Signal Transduction in Wound Healing

Resveratrol is a well-known polyphenol that harbors various health benefits. Besides its well-known anti-oxidative potential, resveratrol exerts anti-inflammatory, pro-angiogenic, and cell-protective effects. It seems to be a promising adjuvant for various medical indications, such as cancer, vascular, and neurodegenerative diseases. Additionally, resveratrol was shown to display beneficial effects on the human skin. The polyphenol is discussed to be a feasible treatment approach to accelerate wound healing and prevent the development of chronic wounds without the drawback of systemic side effects. Despite resveratrol’s increasing popularity, its molecular mechanisms of action are still poorly understood. To take full advantage of resveratrol’s therapeutic potential, a profound knowledge of its interactions with its targets is needed. Therefore, this review highlights the resveratrol-induced molecular pathways with particular focus on the most relevant variables in wound healing, namely inflammation, oxidative stress, autophagy, collagen proliferation and angiogenesis.     

防晒产品中防晒剂的配比研究和优化方法

利用正交设计、通过SPF－290仪器测试法和水分散紫外分光光度法的比较，研究了4种常用防晒剂：T150，Parso15000，Parsol1789,Escalo1557和一种成膜剂V220对配方防晒效果的影响，结果发现：1．水分散分光光度法在防晒配方的筛选和优化中仍具有很大的利用价值。2．获得了一个SPF值在20以上的上述防晒剂的较佳配比。     

一种新型胶乳的合成及其在印刷胶片中的应用

以丙烯酸丁酯 (BA)、苯乙烯 (ST)、丙烯酸 (AA)、丙烯酸羟乙酯 (HEA)、N 羟甲基丙烯酰胺 (MAM)为共聚单体 ,采用预乳化聚合工艺 ,合成出“核壳皮”型共聚乳液。乳液的稳定性良好。研究了乳化剂、引发剂用量、单体组成、滴加速度、温度等因素对聚合反应的影响。讨论了乳液性质对印刷胶片照相性能及冲洗加工性能的影响。结果表明 ,具有“核壳皮”结构的乳液 ,完全满足印刷胶片的使用要求。     

化妆品研发的新理念

论述了化妆品最新发展技术及产品发展的现状。在快速增长的护肤品市场中，各大企业的化妆品化学家们正把具有抗衰老作用的新组分、新技术应用到新产品中来，并纷纷建立自己的咨询机构，以争夺抗衰老竞技场中的领先地位，不过在促进化妆品科学发展的同时也存在许多的问题。     

Mechanisms of Drying of Skin-Forming Materials. II.Droplets of Heat Sensitive Materials

ABSTRACT

Drying studies were carried out on single droplets of gelatin solution, typifying a skin forming, heat-sensitive material. Each droplet was suspended from a novel rotating glass nozzle which enabled direct measurement of its weight and temperature during drying. Observations using this appartatus successfully detected the decrease in core temperature and increase in drying rate resulting from granule dissolution at 30 °C.

The study covered air temperatures in the range 19 °C–175 °C. Scanning Electron Microscopy was used to examine the dried crusts. The resistance of the skin to vapour diffusion was significantly increased with an increase in the air temperature. At air temperature > 60 °C the dried particle lost the structure and properties of the original powder. The optimum drying conditions to avoid this were predicted for this type of skin forming-material.     

丹参挥发油与蒲公英复配物在化妆品中的应用

分别测试丹参挥发油、蒲公英提取物及其复配物的抗氧化、美白、抑菌、细胞毒性和皮肤渗透性等作用，并考察丹参挥发油与蒲公英复配后是否具有协同增效作用。结果表明，复配物的抗氧化性能比二者单独作用效果更强，略高于阳性对照VC；丹参挥发油对酪氨酸酶活性的抑制作用强于阳性对照熊果苷，对酪氨酸酶的抑制类型为竞争性抑制，抑制常数KI为0.0049 mg/L，丹参挥发油与蒲公英两者之间对酪氨酸酶抑制无拮抗作用；复配物对金黄色葡萄球菌的抑制作用好于单一成分，与阳性对照硫酸链霉素效果相当；提取物为100 mg/L浓度时无明显细胞毒性；丹参挥发油与蒲公英复配后，蒲公英提取物的皮肤累计渗透量比单独作用时增大，丹参挥发油可促进蒲公英提取物的透皮吸收，复配物具有协同抗氧化和抑菌功效，无明显细胞毒性，皮肤渗透性较好。     

基于皮肤本态数据库的中青年女性面部皮肤综合状态评价模型构建

从中国女性皮肤本态数据库(北京工商大学)中随机抽取22～42岁女性志愿者1 085例,采集志愿者的皮肤数据,通过相关性分析初步降噪,得到皮肤状态核心指标,并采用KMO检验和巴利特球形检验方法进行检验。根据主成分分析法计算评价模型的各项系数,最终构建皮肤状态综合评价模型。皮肤状态相关的核心指标包括:年龄、皮肤总弹性、皮肤光泽度、黑色素含量、血红素含量、水分含量、经皮水分散失量、肤色ITA°、油脂含量、毛孔数量等10项。该模型对女性的综合皮肤状态给予客观的量化判定,弥补了肉眼判断受到的周围环境以及个人主观意识的影响,解决了皮肤评价的时空限制,采集相关指标数据即可对女性皮肤进行有效评价。研究结果可为女性皮肤状态综合判定提供技术支持。