From observational to analytical morphology of the stratum corneum: progress avoiding hazardous animal and human testings

A pilot study evaluating the efficacy and safety of retinaldehyde-loaded niosomes against mild-to-moderate acne

BACKGROUND

Retinoids are the mainstay of topical therapy for acne. To improve the efficacy and minimize the side effects of retinoids, various novel drug delivery mechanisms, including nanoparticles, have been developed.

AIM

To evaluate the efficacy and safety of a retinaldehyde-loaded niosome (RA-N) nanoemulsion against sebum secretion and keratinization on mild-to-moderate acne.

PATIENTS/METHODS

Twenty-three participants exhibiting mild-to-moderate acne with both closed and open comedones were included. They applied a 0.05% RA-N nanoemulsion daily for 4 weeks, did not to use any other emollient or topical pharmaceutical, and were asked to report any symptoms and treatment satisfaction.

RESULTS

The participants demonstrated significantly fewer closed and open comedones after 2 and 4 weeks of treatment than at baseline (*p < 0.05). The mean sebum secretion, measured using Sebumeter®, was 327.95 ± 90.20 μg cm^-2 at baseline and reduced to 282.60 ± 99.70 and 250.65 ± 97.6 μg cm^-2 , respectively, after 2 and 4 weeks of treatment (*p < 0.05). The mean desquamation index, determined using Visioscan®, was 10.99 ± 1.69 at baseline and decreased to 9.81 ± 1.10 and 8.89 ± 1.32, respectively, after 2 and 4 weeks of treatment (*p < 0.05). The application of the RA-N nanoemulsion resulted in a significantly lower desquamation level, suggesting that the RA-N nanoemulsion was well-tolerated without any skin irritation. None of the participants reported a serious adverse event during this study.

CONCLUSION

Our findings suggest that the RA-N nanoemulsion was effective in improving comedones in acne-prone skin and safe for long-term application. Further studies are necessary to investigate the long-term effects of the application of the RA-N nanoemulsion in participants with inflammatory acne and acne scars.

Contribution of Primary Biological Aerosol Particles to airborne particulate matter in indoor and outdoor environments

The atmospheric concentration of bioparticles was determined in some outdoor and indoor sites by using a commercial low-volume sampler and a detection method based on particle collection on polycarbonate filters, propidium iodide staining, observation by fluorescence microscopy and image analysis. Outdoor sampling was continuously carried out from May 2015 to October 2016 by cumulating monthly samples over individual filters. PBAPs contribution to PM₁₀ concentration was in the range 0.7-13%. Seasonal differences were found in PBAPs concentration, shape and mass distribution. Higher concentrations were recorded during the warm period, when the bioparticles were more numerous, larger and more elongated. Simultaneous indoor and outdoor daily samples were collected during the spring of 2014 and 2017 in domestic environments. In indoor sites PBAPs were much higher in concentration than outdoors and showed a different visual appearance, with very wide polyhedral-shaped particles identifiable as skin flakes. Indoor/outdoor ratio (I/O) of PBAPs was in the range 6-16. Indoors, PBAPs contributed 21-77% to organic matter and 16-68% to PM₁₀. When sampling into a sealed room, I/O was only 0.01 for individual bioparticles heavier than100 ng, while it was in the range 0.24-0.43 for PBAPs below 20 ng. This suggests that the infiltration factor of wide bioparticles was very low and that their concentration increase in indoor environments was due to indoor sources, namely the presence of human beings. Samplings carried out in different rooms of an apartment showed that most of the PBAPs mass was due to particles heavier than 100 ng, particularly in the bedroom.

Plant plasma membrane vesicles interaction with keratinocytes reveals their potential as carriers

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Broccoli root vesicles showed stability and high entrapment efficiency.

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Nanoencapsulation with membrane vesicles provide an efficient system for keratinocytes cell delivery.

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Effectivity is probed by penetrating in skin layers.

During the last few years, membrane vesicles (as exovesicles) have emerged as potential nanocarriers for therapeutic applications. They are receiving attention due to their proteo-lipid nature, size, biocompatibility and biodegradability. In this work, we investigated the potential use of isolated root plasma membrane vesicles from broccoli plants as nanocarriers. For that, the entrapment efficiency and integrity of the vesicles were determined. Also, the delivery of keratinocytes and penetrability through skin were studied. The results show that the broccoli vesicles had high stability, in relation to their proteins, and high entrapment efficiency. Also, the interaction between the vesicles and keratinocytes was proven by the delivery of an encapsulated fluorescent product into cells and by the detection of plant proteins in the keratinocyte plasma membrane, showing the interactions between the membranes of two species of distinct biological kingdoms. Therefore, these results, together with the capacity of brassica vesicles to cross the skin layers, detected by fluorescent penetration, enable us to propose a type of nanocarrier obtained from natural plant membranes for use in transdermal delivery.

Gallic acid loaded poloxamer gel as new adjuvant strategy for melanoma: A preliminary study

The present study describes the production and characterization of poloxamer gels containing the antioxidant molecule gallic acid. The gels were particularly designed in order to obtain a formulation suitable for administration on the skin to treat melanoma. The polymer concentration was selected after rheological characterization and determination of gel transition temperature. In order to study the gallic acid diffusion, in vitro experiments were performed using Franz cells associated to different membranes. As first approach the gallic acid diffusion was evaluated through synthetic membranes, such as cellulose, nylon, polycarbonate, polytetrafluoroethylene, polyvinylidene fluoride and the commercial Strat-M® membrane. The membranes were employed separately or in association and compared to stratum corneum epidermis membranes, in order to find a system able to reproduce the gallic acid diffusion through the skin. Selected membranes were used for studying gallic acid diffusion from poloxamer gel. It was found that the diffusion of gallic acid was dramatically influenced by the type of membrane, both in the case of the aqueous solution or poloxamer gel. Scratch wound healing and migration assays conducted on human keratinocytes and melanoma cells demonstrated the ability of gallic acid loaded gel to inhibit cellular migration, suggesting its potential as adjuvant strategy for melanoma.