- A technology for production of
biosurfactants with moisturizing properties equivalent to those of natural
ceramides is established using yeast cells and vegetable oils.
- The developed technology reduces
production costs to one tenth of natural ceramide products.
-
The present biosurfactants can be used in
cosmetics and for skin care products in the same way as natural
ceramides.
- The biosurfactants easily form a variety
of liquid crystals, and thus have a great potential for highly functional
biomaterials in a variety of industrial fields.
Synopsis
With the collaboration of Toyobo Co., Ltd
(Ryuzo Sakamoto, President), Dai Kitamoto, Group Leader of the Biochemical
Materials Group of the Research Institute for Innovation in Sustainable
Chemistry (Hiromichi Shimada, Director), of the National Institute of Advanced
Industrial Science and Technology (AIST; Hiroyuki Yoshikawa, President), has
succeeded in developing a highly functional biosurfactants.
The developed biosurfactants present superb
skin moisturizing characteristics equivalent to those of natural ceramides, and
it can be used in functional cosmetics and for other skin care products. The
biosurfactants consist of only sugar and fatty acids, and are thus highly
environmentally friendly. They can also be used for high-performance washing
detergents and advanced nanomaterials, because they easily form a variety of
liquid crystals in aqueous solutions.
The present biosurfactants also exhibit a
spontaneous formation of capsules of nanometer size (1 nanometer = 1 x
10-9 meters), so-called liposomes, which
considerably improve the stability of cosmetic ingredients and their
permeability to the skin.
Natural ceramides have been praised for its
moisturizing properties, and together with hyaluronic acids, they have become a
crucial material for skin care applications. However, the use of natural
ceramides set its cost in the range from several hundred thousand yen to several
million yen per kilogram. It has been therefore strongly desired to develop a
safe product with characteristics similar to natural ceramides at a lower cost.
The present R&D has enabled us to develop the desired moisturizing
materials, using yeast fermentation processes and vegetable oils (Figure
1).
Figure 1. Production process
Background of the
Research
In recent years, increasing interest in skin
care awareness, together with advances in the understanding of skin structure,
the aging process, roughening of skin, and sunburn, and elucidation of the
mechanisms of blotch, has led to new materials and treatments being continuously
introduced, with an ever expanding market for highly functional products for
skin care and other skin applications.
Skin care products can be classified into
products that control the moisture evaporation ("control type") such as
hyaluronic acid and products that help to preserve the moisture of the skin
("supplement type") such as amino acids or ceramide. Natural ceramide presents
superb moisturizing characteristics, but the use of natural raw materials makes
the refining process troublesome to obtain a final product of reasonable purity,
and the cost reaches the range from several hundred thousand yen to several
million yen per kilogram. In addition, synthesis of natural or pseudo-ceramide
requires high-level chemical technologies, but it does not contribute to reduce
costs. Not so highly functional but low-cost chemical products are used as
alternatives to natural ceramide. The need for a substitute product for ceramide
that combines low cost and high functionality is evident.
In addition, from the point of view of
safety and environmental concerns, natural products that are not based on
petroleum are required.
History of the
Research
In the search for materials that have low
environmental impact, AIST has tackled the development of a biosurfactant and
established that it is possible to produce it efficiently from vegetable oil
through a process of yeast fermentation. At the same time, to establish the most
advantageous applications for this product, we started to analyze the physical
properties and functions of this biosurfactant.
Based on its accumulated experience in the
field of biotechnology, Toyobo has been opening new fields of applications for
highly functional biomaterials. Toyobo's interest in the biosurfactant developed
by AIST brought the start of collaborative research between the two
entities.
Description of the
Research
Biosurfactants are natural lipids produced
by microbes such as yeast or the bacillus natto, with diverse properties
reflecting their structure. Their main functions are as surface agents (for
emulsification, dispersion, moisturizing, etc.), and they have the
characteristic of being effective even at extremely low concentrations compared
to synthetic reactants. Also, in some cases, biosurfactants have unique
characteristics not observed in synthetic surfactants, such as formation of
diverse liquid crystals, anti-tumor activity, etc. However, to this date, mass
production of biosurfactants has been difficult and their applications and
industrial use were limited.
At AIST, the starting point was the search
for a mass producible microbe, which led to the discovery of a yeast with a
relatively higher productivity than the present biosurfactant. Evaluation of the
production conditions was carried out and a mass production method using olive
oil or other vegetable oils was established (Figure 1). Joint research with
Toyobo led to the development of a method for effective production of the
present biosurfactant, followed by an active search for new applications in the
field of functional materials.
In the quest to establish new applications,
evaluation of the unique structure of the biosurfactant molecular model
(simultaneous coexistence of glucose, sugar alcohol, fatty acid, etc.) showed
its similarity with the ceramide molecule, which is an intercellular lipid. At
the beginning, the lack of a method for accurate assessment of the moisturizing
effect on the skin made it difficult to evaluate the effects of the surfactant.
However, after the joint research with Toyobo was begun, the use of the
three-dimensional cultured skin surface developed by this company became the
breakthrough that accelerated the process for confirmation of the moisturizing
properties of the biosurfactant, and made possible determination of its
suitability for use in skin care products and cosmetics (Figure 2). Regarding
the mechanisms for preservation of moisture, we expect 1) the structure
resembling ceramide will easily penetrate the intercellular spaces in the
stratum corneum, and 2) it will be effective in moisture retention and
maintenance at the skin intercellular level, as it easily forms liquid crystals
(Figure 3).
Figure 2. Moisturizing effect of biosurfactants on cultured human
skin
Figure 3. Effects of biosurfactants on rough skin
Furthermore, as the biosurfactant easily
forms capsule of nano-meter size (liposome), it is easy to mix with other
cosmetic components, which could contribute to stabilization of these components
(capsule protection effect), and improves the permeability to the skin (capsule
affinity effect).
From the point of view of the production
process, fermentation of yeast can yield a high purity biosurfactant, with a
cost reduction in the order of one fifth to one tenth of the current costs of
producing natural ceramide from vegetables, or synthesizing pseudo-ceramide
through chemical processes (several hundred thousand yen to several million yen
per kilogram). The present production method does not use petroleum but biomass
resources as a raw material, achieving production in one step by fermentation of
vegetable oils. Compared with other chemical processes, high expectations are
set on it as a resource saving and low environmental impact process.
Future Prospects
Biosurfactants that can be used in skin care
products (cosmetics, medicines for external application) are the focus of
attention. Through application of microbial biotechnology, AIST is engaged in
the search for and development of biosurfactants with new structures and new
properties. Toyobo, with vast experience in the field of biotechnology, is
making inroads in the field of functional biomaterials. Starting from the autumn
of this year, we will provide samples to diverse manufacturers in the field with
the aim of achieving industrialization in a two or three year span. Lowering of
costs is another topic to be pursued, as is the discovery of new applications
aside from cosmetic products that take advantage of the superb characteristics
of the surfactant. |