Shiseido develops technology to control the volume of hyaluronic acid

 Shiseido has developed "Shape-Shifting HA technology" that controls the volume of hyaluronic acid (HA).

HA, which forms a water-retaining film on the surface of the skin and exerts a high moisturizing effect, has a problem that it does not easily penetrate into the stratum corneum even if it is applied to the skin because the molecule is very large. By controlling the volume of a certain HA, it is said that the penetration of HA into the stratum corneum and the function in the stratum corneum can be enhanced, and soft and fresh skin can be realized.

HA is a biopolymer with excellent water retention and is known to exhibit various physiological activities in addition to moisturizing the skin. Since the amount of HA contained in the epidermis decreases with age, it is important to supply HA to the inside of the skin in order to maintain healthy skin. However, it was extremely difficult for HA to penetrate the skin because the molecule of HA is very large and the stratum corneum acts as a tough barrier. In addition, HA injection in aesthetic medicine, which can be directly injected into the subcutaneous tissue, is invasive and has a problem that it cannot be applied to the entire face.

Therefore, we proceeded with the development of a new technology that allows the high molecular weight HA to penetrate into the skin non-invasively and the HA that has penetrated into the skin to exert its original function.

In the study, various salts were added to the HA aqueous solution and the permeation amount of HA into the stratum corneum was measured. As a result, it was clarified that the addition of magnesium chloride (MgCl2) increased the permeation amount of HA into the stratum corneum. To support this, HA labeled with green fluorescence was applied to the surface of the skin, and the cross section was observed with a fluorescence microscope. When MgCl2 was added, it was more than the HA aqueous solution without MgCl2 addition. We were able to visualize how HA penetrated deep into the stratum corneum.

In addition, when MgCl2 was added to the HA aqueous solution and the volume of HA was measured, a decrease in volume was observed due to the addition of MgCl2. From these results, it is considered that MgCl2 increased the permeability of HA in the stratum corneum by contracting the volume of HA.

Furthermore, when SMP is added to HA (compact HA) that has shrunk due to the addition of sodium metaphosphate (SMP), which is a type of chelating agent, the compact HA re-swells and the volume increases, which is equivalent to the volume of HA before shrinkage. I found out that I would return to.

Next, in order to verify the effect of the combination of compact HA and SMP, we compared the water content of the stratum corneum when only compact HA was applied to the surface of the skin and when the SMP aqueous solution was applied after applying compact HA. .. As a result, it was clarified that the water content of the stratum corneum increased remarkably when SMP was added to the compact HA.

From this result, it is considered that as a result of the re-swelling of HA by SMP, the water retention capacity was restored and the water content of the stratum corneum was increased.

The company named "Shape-Shifting HA" a series of technologies that shrink the polymer HA and make it easier to penetrate into the stratum corneum by re-swelling it with a chelating agent such as SMP to improve the water retention capacity of the skin. rice field.