促渗剂对尼莫地平体外经皮渗透的影响

目的建立简便的紫外分光光度法测定尼莫地平体外经皮渗透量，并考察不同促渗剂对尼莫地平的体外经皮渗透影响。方法运用紫外分光光度法测定尼莫地平通过鼠皮的体外经皮渗透量，采用改良的Franz扩散池研究不同促渗剂对尼莫地平经皮渗透的影响。结果所选用的促渗剂均对尼莫地平有一定的促渗作用，油酸的促渗作用比较明显。结论油酸对尼莫地平的促渗效果较好。     

不同促渗剂对苗药秤钩风的透皮吸收特性研究

目的考察不同促渗剂对苗药秤钩风提取物经皮吸收的影响。方法采用改良Franz扩散池,以离体昆明小鼠皮肤为屏障,用高效液相色谱法测定透皮吸收影响因素对苗药秤钩风提取物的渗透吸收速率、增渗倍数、滞后时间等参数的影响,对氮酮、油酸、冰片促渗效果进行考察。结果氮酮、3%油酸和冰片水溶液对秤钩风提取物的经皮吸收速率常数分别为（214.187 2±13.569 0）、（227.554 4±9.849 0）、（168.118 7±21.564 0）μg/（cm2·h）,相较于未加促渗剂时的经皮吸收速率常数（133.276±11.312）μg/（cm2·h）,增渗倍速分别为1.61、1.71、1.26;3种促渗剂对秤钩风提取物的经皮吸收滞后时间分别为2.108 1、1.825 6、2.965 5 h。结论油酸和氮酮对秤钩风提取物的经皮吸收有良好的促进作用,3%油酸效果最佳;冰片对秤钩风的经皮吸收也存在促进作用,但是滞后时间延长。     

Role of solvent in interactions between fatty acids-based formulations and lipids in porcine stratum corneum.

Fatty acids are commonly used as permeation enhancers to increase skin permeation of drug molecules by interacting with the intercellular lipids in the skin. The influences of the chain length of the fatty acid in different solvents on the stratum corneum (SC) lipids were investigated to further understand the mechanism of permeation enhancement of fatty acids. Gravimetric studies showed that SC absorbed propylene glycol (PG)-based formulations to a greater extent than mineral oil (MO)-based formulations and there was no correlation between the nature of fatty acid and the formulation uptake for PG-based formulations. High formulation uptake was only observed for MO-based formulation when more hydrophilic acids like acetic acid and propionic acid were added. Spectroscopic studies revealed that the vibrations of alkyl chains in the stratum corneum lipids were dependent on the solvent used. Fatty acids with short chains were able to perturb the SC lipids in lipophilic MO but not in PG based on symmetric peak shifts. For the PG-based formulations, skin perturbation was attained when long chain fatty acid such as oleic acid was present. The results showed that the nature of solvent played an important role in the interactions between the fatty acids and the intercellular lipids in the SC. These findings would make an important contribution to the choice of solvent in transdermal drug delivery systems.     

急性肺损伤炎性细胞凋亡异常及粒细胞集落刺激因子调控的研究

目的 探讨急性肺损伤时支气管肺泡灌洗液(BALF)中的中性粒细胞(PMN)凋亡发生规律及其与粒细胞集落刺激因子调控关系.方法 豚鼠30只,分为3组:组1为生理盐水正常对照组,组2为油酸致病组,组3为油酸+粒细胞集落刺激因子组.组2、组3分别由尾静脉注射油酸(0.12 ml/kg)造成豚鼠急性肺损伤模型.组1则注入生理盐水.组3在实验造模前2 d由皮下注射粒细胞集落刺激因子1.0μg/kg,1次/d.组1、组2、组3分别于注射后2 h用生理盐水进行全肺支气管肺灌洗,收集BALF.用梯度密度法离心收集PMN.用原位末端标记法检测BALF中PMN凋亡.结果 组2、组3和组1BALF中PMN凋亡百分比分别为(2.500±1.080)%、(3.500±0.850)%、(6.400±1.505)%.组2、组3较组1 BALF中PMN凋亡均显著降低(均P＜0.01).结论 急性肺损伤炎性细胞PMN凋亡延迟,PMN持续激活和释放毒性内容物与肺损伤有密切关系.粒细胞集落刺激因子能调控干预急性肺损伤时PMN凋亡延迟.     

Dielectric properties of poly-(3-octylthiophene) thin films mixed with oleic acid capped cadmium selenide nanoparticles

Hybrid heterojunction thin films, based on poly-(3-octylthiophene) (P3OT) polymer and oleic acid (OA)-capped cadmium selenide (CdSe) nanoparticles (NPs) are prepared by a spin-coating method. The structural and morphological properties of the CdSe NPs and of the hybrid thin films are investigated. The results of the dielectric characterization show that conductivity of the hybrid thin films is dependent on frequency and CdSe NP concentration. The Nyquist plots of the impedance characteristics of the layers exhibit circular features irrespective of the NP concentration. The dependence of the dielectric permittivity on frequency and CdSe NP concentration are studied.

Hybrid heterojunction thin films, based on poly-(3-octylthiophene) (P3OT) polymer and oleic acid (OA)-capped cadmium selenide (CdSe) nanoparticles (NPs) are prepared by a spin-coating method.     

不同剂量猪肺表面活性物质对大鼠油酸型急性肺损伤疗效的影响

目的 探讨不同剂量猪肺表面活性物质（PPS）混悬液对油酸致大鼠急性肺损伤（ALI）的治疗作用及量-效关系。方法56只SD大鼠按随机数字表法分为假手术组、油酸模型组和5个不同剂量PPS治疗组。静脉注入油酸诱发大鼠ALI，30min后治疗组和模型组经气管分别滴入50、80、100、150和200mg／kg PPS和等量生理盐水。实验过程中计数大鼠呼吸频率，测定动脉血气。4h后处死，计算大鼠存活率，观察肺组织形态学改变，并检测肺系数、支气管肺泡灌洗液（BALF）中总蛋白含量和血浆肿瘤坏死因子-α（TNF-α）的浓度。结果与模型组比较，PPS50mg／kg组有减慢呼吸频率、短时间内提高动脉血氧分压（PaO2）的作用，但是并不能明显改善肺损伤；PPS80～200mg／kg组除改善呼吸功能外，大鼠肺毛细血管通透性、肺出血、肺水肿、血浆TNF-α浓度以及大鼠死亡率也均明显降低（P均〈0．05）。显示高剂量PPS（150～200mg／kg）在减轻炎症反应和肺损伤方面具有更好的效果。结论单独应用PPS能明显改善早期油酸型ALI大鼠的呼吸功能，≥80mg／kg的PPS有明显减轻肺损伤的作用，而各剂量之间无量-效关系。     

The effect of alcohols as vehicles on the percutaneous absorption and skin retention of ibuprofen modified with l-valine alkyl esters

The effect of various alcohols as vehicles on skin permeability was compared for unmodified ibuprofen (IBU) and ion pairs of ibuprofen with l-valine alkyl esters [ValOR][IBU], in which the alkyl chain R was changed from C1 to C8. In vitro permeation experiments were conducted in a Franz cell with porcine skin. Methanol, ethanol, and isopropanol solutions of 70% (v/v) were chosen as vehicles for penetrants and a buffer solution of pH 5.4 or 7.4 as the acceptor phase. The comparisons of permeation profiles for various [ValOR][IBU] from different alcohols were determined. The cumulative mass, skin accumulation, steady-state flux, diffusion coefficient, and lag time were investigated and compared. It was observed that i-propanol was the best enhancer of skin permeation of both unmodified ibuprofen and its salts with l-valine alkyl esters for both acceptor phases. The permeability of the various carriers increases with increasing chain-length of the alcohol. In most cases, significantly higher cumulative mass was found in the acceptor buffer of pH 7.4. The conjugate of ibuprofen with l-valine propyl ester [ValOPr][IBU] permeated the skin to the highest degree in comparison to unmodified ibuprofen. The accumulation of ibuprofen was higher for all salts in relation to the parent acid applied onto the skin. The greatest amounts of ibuprofen were accumulated in the skin when ibuprofen was used as the ionic pair with l-valine butyl ester, [ValOBu][IBU] in the i-propanol solution and pH 7.4 buffer as the acceptor phase.

The effect of various alcohols as vehicles on skin permeability was compared for unmodified ibuprofen (IBU) and ion pairs of ibuprofen with l-valine alkyl esters [ValOR][IBU], in which the alkyl chain R was changed from C1 to C8.     

In-vitro release and transdermal fluxes of a highly lipophilic drug and of enhancers from matrix TDS.

Transdermal systems (TDS) are a well-known application form for small, moderately lipophilic molecules. The aim of this study was to investigate the possibility of applying a highly lipophilic drug, the antiestrogen AE (log P=5.82) transdermally by polyacrylate-based matrix TDS. For this purpose, two effects of both drug and enhancer concentration in TDS were investigated: in-vitro release and transdermal permeation of drug and enhancers. In the TDS investigated, in-vitro release as well as in-vitro permeation of AE through excised skin of hairless mice was found to be independent of concentrations of both drug and enhancers. The steady-state fluxes observed were low (about 50-100 ng cm(-2) h(-1)). But skin pretreatment with permeation enhancers resulted in a markedly enhanced permeability (1400 ng cm(-2) h(-1)). Therefore, the permeation of this highly lipophilic drug seems to be limited by the stratum corneum barrier function. In contrast, the transdermal permeation of the enhancers was dependent on the TDS composition. Increase in enhancer content resulted in a higher permeation of enhancers, whereas skin pretreatment did not. In conclusion, it was shown that the highly lipophilic antiestrogen can be administered transdermally by pretreating the skin with the fluid permeation enhancer combination propylene glycol-lauric acid (9+1) and then applying a matrix TDS.     

不同时间给予猪肺表面活性物质对大鼠油酸型急性肺损伤疗效的影响

目的 探讨不同时间给予猪肺表面活性物质(PPS)混悬液对油酸致大鼠急性肺损伤(ALI)的治疗作用.方法 将48只SD大鼠随机分为假手术组、模型组、0.5 h PPS治疗组和2 h PPS治疗组.假手术组仅行气管和颈动脉插管手术操作,其余各组大鼠静脉注入油酸诱发ALI;0.5 h PPS治疗组和2 h PPS治疗组分别于油酸注入后0.5 h和2 h经气道均滴入100 mg/kg和150 mg/kg两个剂量的PPS,实验过程中计数大鼠呼吸频率,测定动脉血气指标;于实验4 h计算大鼠存活率后处死动物,观察肺组织病理学改变,并检测肺系数及支气管肺泡灌洗液(BALF)中总蛋白(TP)含量和血浆中肿瘤坏死因子-α(TNF-α)浓度.结果 与模型组比较,0.5 h给予PPS 100 mg/kg和150 mg/kg以及2 h给予PPS 150 mg/kg治疗都能显著降低大鼠的呼吸频率,提高动脉血氧分压(PaO2)及大鼠存活率,降低肺毛细血管通透性及肺出血、肺水肿发生率,降低血浆中TNF-α和BALF中TP含量(P均＜0.05).而2 h给予100 mg/kg PPS的治疗作用不明显.结论 早期气道内滴入≥100 mg/kg的PPS,能明显改善油酸型ALI大鼠的呼吸功能、减轻肺损伤;晚期较大剂量的PPS(150 mg/kg)才有治疗作用.     

In vitro acanthamoebicidal activity of a killer monoclonal antibody and a synthetic peptide

OBJECTIVES: To evaluate the in vitro microbicidal activity against Acanthamoeba castellanii of a murine monoclonal anti-idiotypic antibody (KTmAb) and a synthetic killer mimotope (KP), which mimic a yeast killer toxin (KT) characterized by a wide spectrum of antimicrobial activity through interaction with specific cell wall receptors, mainly constituted by beta-glucans. METHODS: Amoebicidal activity was investigated after incubation of trophozoites under different experimental conditions with laminarinase, KTmAb, KP and a scrambled decapeptide (SP). To confirm the specific interaction of KP with beta-glucans, the experiments were also carried out in the presence of laminarin (beta1-3-glucan) or pustulan (beta1-6-glucan); both glucan molecules were co-incubated with KP or SP. RESULTS: KTmAb and KP exhibited a time-dependent killing activity, in comparison with SP or heat-inactivated KTmAb; this activity was completely abolished by pre-incubation with laminarin, but not by pustulan. Notably, in vitro amoebicidal activity was observed in the presence of laminarinase, an enzyme that specifically hydrolyses beta-glucans. Furthermore, KP specifically inhibited the growth of Acanthamoeba on infected contact lenses and the remaining adherent KP-treated trophozoites appeared strongly damaged. CONCLUSIONS: The results indicate that the expression of beta1-3-glucan receptors in the cell membrane is probably modulated during cell growth of A. castellanii and is critical for the killing activity of KT-like molecules. Our data confirm the broad antimicrobial spectra of KTmAb and KP, emphasize the crucial role of beta1-3-glucan in microbial physiology and suggest the potential use of KTmAb and KP in the prevention and therapy of Acanthamoeba infections or in preventing Acanthamoeba contamination during storage of contact lenses.     

Melanocyte repopulation in full-thickness wounds using a cell spray apparatus

Melanocyte restoration is critical in reconstituting skin color. We developed a spotted (piebald) pig wound model to study methods of restoring melanocytes to the epidermis. Paired, full-thickness, porcine wounds were covered with nonpigmented, fully expanded, 3:1 meshed, split-thickness skin grafts and were sprayed with an epidermal cell suspension. The suspensions were highly pigmented skin (HPS) cell isolates for half of the wounds (n = 16) and nonpigmented skin (NPS) cell isolates for the remaining wounds (n = 16). Histologic sections showed 6.0 +/- 3.0 and 15 +/- 4.0 pigmented melanocytes per high-power field on days 8 and 20 in HPS-treated wounds and no pigmented melanocytes in NPS-treated wounds. Melanin pigment was dispersed in all layers of the epithelium for the HPS group on day 20 compared with a lack of melanin pigment observed in the NPS group. Cell spraying may provide a clinical method to restore color to skin; further work is needed to control the expression of melanin.     

Regulatory effects of hydrogen sulfide on alveolar epithelial cell endoplasmic reticulum stress in rats with acute lung injury

BACKGROUND: The present study was undertaken to examine the regulatory effect of hydrogen sulfide(H2S) on endoplasmic reticulum stress in alveolar epithelial cells of rats with acute lung injury(ALI) induced by oleic acid(OA).METHODS: Seventy-two male Sprague Dawley(SD) rats were divided into control group, oleic acid-induced ALI group(OA group), oleic acid-induced ALI with sodium hydrosulfide(Na HS) pretreatment group(OA+Na HS group), and sodium hydrosulfide treatment group(Na HS group). Rats of each group were further subdivided into 3 subgroups. Index of quantitative assessment of histological lung injury(IQA), wet/dry weight ratio(W/D) and H2 S level of lung tissues were measured. The expressions of endoplasmic reticulum stress markers including glucose-regulated protein 78(GRP78) and α-subunit of eukaryotic translation initiation factor-2(el F2α) in lung tissues were measured by immunohistochemical staining and Western blotting.RESULTS: The IQA score and W/D ratio of lung tissues at the three time points significantly increased in rats injected with OA, but significantly decreased in other rats injected with OA and Na HS. The level of H2 S in lung tissue at the three time points significantly decreased in rats injected with OA, but significantly increased in other rats injected with both OA and Na HS. GRP78 and el F2α decreased in rats injected with OA, but increased in other rats injected with both OA and Na HS, especially at 4-hour and 6-hour time points.CONCLUSION: The results suggested that H2 S could promote alveolar epithelial cell endoplasmic reticulum stress in rats with ALI.     

Oleic acid, a skin penetration enhancer, affects Langerhans cells and corneocytes

Permeation enhancers (PE) are frequently used in the field of dermal research and for the development of transdermal delivery products. However, their influence on skin epidermal Langerhans cells (LC) has not yet been investigated. In this work we studied the effect of four PE, oleic acid (OA), propylene glycol (PG), ethanol, and diethylene glycol monoethyl ether (DGME), and an iontophoretic treatment on the morphometric parameters of epidermal Langerhans cells (LC). Retinoic acid (RA) was used as a positive control. Test solutions were applied to the footpad of Sabra mice. The area, perimeter, density and shape factor (SF) were the morphometric parameters evaluated following ATPase staining of LC. Application of RA led to a large decrease in cell density (−50.2%, P<0.01) and dendritic shape (19.8%, P<0.01). Treatment with 10% OA in ethanolic solution caused a severe decrease in LC density (−69.0%, P<0.01), accompanied by a decrease in dendricity as measured by the changes in SF. Ethanol had no statistically significant effect on the LC morphologic parameters tested. All other PE had a mild, if any, effect on LC morphology. SEM micrographs of the skin of IOPS hairless rats demonstrated that 24 h in vivo treatment with 10% OA in ethanolic solution resulted in the generation of pores on the surface of epidermal corneocytes.     

A study of microemulsion systems for transdermal delivery of triptolide.

Triptolide possesses immunosuppressive, anti-fertility and anti-cancer activities. Due to its severe toxicity, microemulsions with controlled, sustained and prolonged delivery of triptolide via a transdermal route are expected to reduce its adverse side effects. The purpose of the present study was to investigate the microemulsions for transdermal delivery of triptolide. The pseudo-ternary phase diagrams were developed and various microemulsion formulations were prepared using oleic acid as an oil, Tween 80 as a surfactant and propylene glycol as a cosurfactant. The droplet size of microemulsions was characterized by photocorrelation spectroscopy. The transdermal ability of triptolide from microemulsions was evaluated in vitro using Franz diffusion cells fitted with mouse skins and triptolide was analyzed by high-performance liquid chromatography. The effect of menthol as a permeation enhancer, and the loading dose of triptolide in microemulsions on the permeation rate were also evaluated. The triptolide-loaded microemulsions showed an enhanced in vitro permeation through mouse skins compared to an aqueous solution of 20% propylene glycol containing 0.025% triptolide. The permeation of microemulsions accorded with the Fick's first diffusion law. No obvious skin irritation was observed for the studied microemulsion ME6, but the aqueous solution of 20% propylene glycol containing 0.025% triptolide revealed the significant skin irritation. The results indicate that the studied microemulsion systems, especially ME6, may be promising vehicles for the transdermal delivery of triptolide.     

Interrelation of permeation and penetration parameters obtained from in vitro experiments with human skin and skin equivalents.

In a comparative study, two different in vitro cutaneous test systems were examined: (1) The Franz diffusion cell (FD-C), a test system to study drug permeation through the skin and to obtain data like steady state flux and lag time as well as permeability and diffusion coefficients. (2) The Saarbruecken penetration model (SB-M), a test system to investigate drug penetration into different skin layers and after varying incubation times to acquire values about the quasi steady state drug amounts in the stratum corneum (SC). Three drug concentrations (0.9, 0.45 and 0.225%) of a lipophilic model drug preparation, flufenamic acid in wool alcohols ointment, were applied on the skin's surface using 'infinite dose' conditions. Trypsin-isolated SC, heat-separated epidermis, full-thickness skin and reconstructed human skin (RHS) served as skin membranes in the FD-C, while the SB-M experiments were only carried out using full-thickness skin. Increasing steady state flux data and m(ss) values (steady state drug amount in the SC) were detectable after the application of rising drug amounts. Concerning the permeability of the used skin membranes in establishing barrier properties, the following rank order was observed: RHS>SC> or =epidermis>full skin. The flux data of the FD-C experiments for isolated SC, separated epidermis and RHS were linearly related with the m(ss) values of the SB-M investigations, allowing a direct comparison of permeation with penetration parameters. Concerning the drug amount in the SC, previous investigations succeeded in the establishment of an in vivo/in vitro correlation. Based on the results presented here, the prediction of drug amounts present in the SC after different incubation times in vivo is now possible after penetration as well as permeation experiments using the lipophilic model drug preparation, flufenamic acid in wool alcohols ointment.     

Evaluation of novel soya-lecithin formulations for dermal use containing ketoprofen as a model drug.

In this study soya-lecithin aggregates, prepared by a technique using compressed gas, are used to formulate new dermal preparations. Ketoprofen (KP), a nonsteroidal anti-inflammatory drug (NSAID) is included as a model drug. The technique offers the possibility of incorporating auxiliary agents, such as penetration enhancers, anti-irritants and moisturisers together with the drug in one process. Apparent partition coefficients for n-octanol-phosphate buffer were determined for each of the lecithin aggregates. In general, soya-lecithin improves the partition of KP into n-octanol. The resulting products were included in widely used hydrophilic and hydrophobic vehicles. After 24 h, the cumulative amount of drug released through an artificial membrane was higher from the hydrophilic gels (2.6-4.3 mg) and the hydrophobic creams (0.23-0.392 mg) than from the control preparations (control hydrogel: 1.3 mg; control hydrophobic cream: 0.141 mg). However, the cumulative amount released from the hydrophobic vehicles was generally lower than from the hydrophilic matrices. Cumulative amounts such as those released from the hydrophilic preparations can also be achieved using supersaturated formulations based solely on the drug-loaded lecithin aggregates and a suitable oily component (4.07 mg). Results from the diffusion studies using artificial membranes were confirmed by permeation studies using excised rat skin. The improvement in skin permeation is related to both the solubilising effect of the lecithin matrix and the penetration enhancing effect of lecithin itself. The novel soya-lecithin aggregates are promising candidates for new drug delivery systems in dermatology and cosmetology. Lecithin aggregates loaded with drugs are multifunctional carriers that also act as penetration enhancers.     

The synergic effects of various electrolytes and electroporation on the in vitro skin permeation of calcein.

Various electrolytes in test solutions applied to the skin were evaluated with regard to their effects on enhanced skin permeation of calcein as a model permeant by electroporation (EP), which is a physical means to increase skin penetration by applying a high voltage pulse on the skin surface. Calcein solution (1.0 mM) containing different electrolytes at a concentration of 150 mM was applied to excised hairless rat skin, and a 10-ms electric pulse of 300 V was applied to the skin surface ten times (one pulse every second) at the beginning of the in vitro permeation experiments. The following results were obtained: (i) addition of several electrolytes, such as CaCl2 and NaCl, further increased the EP-enhanced skin permeation of calcein when compared to treatment without these electrolytes; (ii) Ca2+ and Mg2+ exerted a greater effect than other cations (Na+, Zn2+, Cu2+, Fe3+ and Al3+); (iii) with simultaneous application of CaCl2 and EP, the effect of anodal EP was much greater than that of cathodal EP; (iv) the penetration-enhancing effects of CaCl2 were also obtained with EP pretreatment followed by calcein addition; and (v) skin permeation was greatly increased particularly with simultaneous application of EP and Ca2+. These substantial combined synergic effects of EP and electrolytes, particularly those containing CaCl2, MgCl2 and CaBr2, may be related to the disruptive and retrievable functions of the biggest barrier of skin, the stratum corneum, of these electrolytes.     

全氟化碳汽化吸入预处理对急性肺损伤实验兔早期炎症因子的影响

目的：探讨全氟化碳（PFC）汽化吸入预处理对油酸型兔急性肺损伤（ALI）早期炎症因子的干预作用。方法：实验兔12只随机分为对照组和PFC预处理组,每组6只。动物麻醉后气管插管行机械通气,对照组注油酸造ALI模型后行机械通气120min,预处理组在造模前先于经气管内汽化吸入PFC60min,再注油酸造AU模型后行机械通气120min。两组分别于麻醉通气30min（基础值）、ALI造模成功时、ALI后30、60、90、120min各时点检测氧合指数、PaO2、PaCO2。实验结束后留取静脉血离心取上清液,对左肺进行肺灌洗留取肺灌洗液,应用ELISA法检测血清及肺灌洗液中TNF-α、IL-1β的含量。结果：与对照组比较,PFC预处理组在各时点的氧合指数和PaO2均明显升高、PaO2明显下降（P均〈0．05）。PFC预处理组血清和肺灌洗液中TNF-α的含量分别为（211±1）ng／L、（326±9）ng／L,明显低于对照组（226±2）ng／L、（368±11）ng／L（P均〈0．05）;PFC预处理组血清和肺灌洗液中IL-1β的含量分别为（77±2）ng／L、（93±2）ng／L,也明显低于对照组（99±3）ng／L和（116±2）ng／L（P均〈0．05）。结论：经气道汽化吸入PFC预处理60min,可改善油酸型AU实验兔的氧合状况,减少早期炎症因子TNF-α、IL-1β的释放。     

Protein–lipid complexes: molecular structure,current scenarios and mechanisms of cytotoxicity

Some natural proteins can be complexed with oleic acid (OA) to form an active protein–lipid formulation that can induce tumor-selective apoptosis. The first explored protein was human milk α-lactalbumin (α-LA), called HAMLET when composed with OA in antitumor form. Several groups have prepared active protein–lipid complexes using a variety of approaches, all of which depend on target protein destabilization or direct OA–protein incubation to alter pH to acid or alkaline condition. In addition to performing vital roles in inflammatory processes and immune responses, fatty acids can disturb different metabolic pathways and cellular signals. Therefore, the tumoricidal action of these complexes is related to OA rather than the protein that keeps OA in solution and acts as a vehicle for transferring OA molecules to tumor cells. However, other studies have suggested that the antitumor efficacy of these complexes was exerted by both protein and OA together. The potential is not limited to the anti-tumor activity of protein–lipid complexes but extends to other functions such as bactericidal activity. The protein shell enhances the solubility and stability of the bound fatty acid. These protein–lipid complexes are promising candidates for fighting various cancer types and managing bacterial and viral infections.

Some natural proteins can be complexed with oleic acid (OA) to form an active protein–lipid formulation that can induce tumor-selective apoptosis.     

Penetration of chlorhexidine into human skin

This study evaluated a model of skin permeation to determine the depth of delivery of chlorhexidine into full-thickness excised human skin following topical application of 2% (wt/vol) aqueous chlorhexidine digluconate. Skin permeation studies were performed on full-thickness human skin using Franz diffusion cells with exposure to chlorhexidine for 2 min, 30 min, and 24 h. The concentration of chlorhexidine extracted from skin sections was determined to a depth of 1,500 μm following serial sectioning of the skin using a microtome and analysis by high-performance liquid chromatography. Poor penetration of chlorhexidine into skin following 2-min and 30-min exposures to chlorhexidine was observed (0.157 ± 0.047 and 0.077 ± 0.015 μg/mg tissue within the top 100 μm), and levels of chlorhexidine were minimal at deeper skin depths (less than 0.002 μg/mg tissue below 300 μm). After 24 h of exposure, there was more chlorhexidine within the upper 100-μm sections (7.88 ± 1.37 μg/mg tissue); however, the levels remained low (less than 1 μg/mg tissue) at depths below 300 μm. There was no detectable penetration through the full-thickness skin. The model presented in this study can be used to assess the permeation of antiseptic agents through various layers of skin in vitro. Aqueous chlorhexidine demonstrated poor permeation into the deeper layers of the skin, which may restrict the efficacy of skin antisepsis with this agent. This study lays the foundation for further research in adopting alternative strategies for enhanced skin antisepsis in clinical practice.