Encapsulation of cycloastragenol in phospholipid vesicles enhances transport and delivery across the skin barrier

Ultrathin silk nanofiber-carbon nanotube skin tattoos for wirelessly triggered and temperature feedbacked transdermal drug delivery

Transdermal drug delivery has emerged as an alternative to conventional drug delivery systems as it enables painless and convenient drug administration. However, next-generation healthcare systems need to facilitate "on-demand" delivery operations and should be highly efficient to penetrate the physiological barriers in the skin. Here, we report an ultrathin dye-loaded epidermal tattoo (UDET) that allows wirelessly stimulated drug delivery with high efficiency. The UDET consists of an electrospun dye-loaded silk nanofiber mat and a covered carbon nanotube (CNT) layer. UDETs are conformally tattooed on pigskins and show stable operation under mechanical deformation. Biological fluorescence dyes such as vitamin B12, riboflavin, rhodamine B, and sodium fluorescein are applied as model drugs. Illuminating the UDET by a low-power light-emitting diode (< 34.5 mW/cm2) triggers transdermal drug delivery due to heat generation. The CNTs convert the absorbed light into heat, and then the dyes loaded on silk can be diffused through the epidermis. The CNT layer is electrically conductive and can detect the temperature by reading the resistance change (0.1917 Ω/°C). This indicates that the UDET can be used simultaneously to read temperature and deliver the loaded dye molecules, making it a promising on-demand drug delivery strategy for future medicine technology.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13534-024-00363-6.

Preparation and characterization of bionics Oleosomes with high loading efficiency: The enhancement of hydrophobic space and the effect of cholesterol

Liposomes (LIP) loaded with natural active ingredients have significant potential in the food industry. However, their low loading efficiency (LE) hampers the advancement of liposomal products. To improve the loading capacity of functional compounds, bionic oleosomes (BOLE) with a monolayer of phospholipid membranes and a glyceryl tricaprylate/caprate (GTCC) oil core have first been engineered by high-pressure homogenization. TEM revealed that the core of BOLE consists of GTCC instead of water, thereby extending the hydrophobic space. Steady-state fluorescence and active loading experiments confirmed that cholesterol (CH) detached from the phospholipid membrane and entered the oil core, where it repelled cannabidiol (CBD). Based on the extending hydrophobic space, CBD-BOLE was prepared and its LE was 3.13 times higher than CBD-LIP. The CBD-phospholipid ratio (CPR) of CBD-BOLE significantly improved at least 7.8 times. Meanwhile, the free radical scavenging activity of CBD was increased and cytotoxicity was reduced.

Transethosome: An ultra-deformable ethanolic vesicle for enhanced transdermal drug delivery

Drug delivery through the skin improves solubility, bioavailability, and unwanted systemic side effects of the drug. The selection of a suitable carrier is a challenging process. The conventional lipid vesicles have some limitations. They deliver the drug in the stratum corneum and have poor colloidal stability. Here comes the need for ultra-deformable lipid vesicles to provide the drug beyond the stratum corneum. Transethosomes are novel ultra-deformable vesicles that can deliver drugs into deeper tissues. The composition of transethosomes includes phospholipid, ethanol and surfactants. Each ingredient has a pivotal role in the properties of the carrier. This review covers the design, preparation method, characterisation, and characteristics of the novel vesicle. Also, we cover the impact of surfactants on vesicular properties and the skin permeation behaviour of novel vesicles.

Nanocarriers as Active Ingredients Enhancers in the Cosmetic Industry-The European and North America Regulation Challenges

“Flawless skin is the most universally desired human feature” is an iconic statement by Desmond Morris. Skin indicates one´s health and is so important that it affects a person’s emotional and psychological behavior, these facts having propelled the development of the cosmetics industry. It is estimated that in 2023, this industry will achieve more than 800 billion dollars. This boost is due to the development of new cosmetic formulations based on nanotechnology. Nanocarriers have been able to solve problems related to active ingredients regarding their solubility, poor stability, and release. Even though nanocarriers have evident benefits, they also present some problems related to the high cost, low shelf life, and toxicity. Regulation and legislation are two controversial topics regarding the use of nanotechnology in the field of cosmetics. In this area, the U.S. FDA has taken the lead and recommended several biosafety studies and post-market safety evaluations. The lack of a global definition that identifies nanomaterials as a cosmetic ingredient is a hindrance to the development of global legislation. In the EU, the legislation regarding the biosafety of nanomaterials in cosmetics is stricter. “The cost is not the only important issue, safety and the application of alternative testing methods for toxicity are of crucial importance as well”.