"Wellness" finish with Vitamin E - I

Functional aspects for clothing textiles, which promote the wearing comfort and well-being have become a striking sales argument. The following article introduces a product idea for "Wellness Textiles". It describes a transfer system consisting of textile/cyclodextrin-vitamin E complex. Transition of vitamin E from the textile material into a skin model could be proven for the first time by means of MALDI-TOF-Mass Spectrometry say Robert Zyschka, Dr Ralf Bruckmann, Dr Bernd Kammerer and Hans Schreiber

Wellness is by long more than just a buzzword for wellbeing, vitality and fitness. It has become a social phenomenon which confers the wish of 'eternal youth' to ageing persons. The term 'wellness' has become a new life philosophy and from the commercial aspect is an important pulse generator and growth motor for many trade brances.

The 'wellness' fever has also reached the field of textile finishing and blew in some 'fresh wind' to this field with innovative product ideas. The following article describes a so-called transfer system by which vitamin E is converted from the textile onto the human skin. For the first time the transfer of vitamin E from the textile material into a skin model could be proven in an experiment.

Vitamin E ( a-Tocopherol)

Vitamin E belongs to the group of lipid-soluble vitamins and is found in nature in many vegetable oils. The chemical term for vitamin E is "a-Tocopherol".(alpha-Tocopherol)

In the cosmetic industry vitamin E is used as antioxidant and active substance among others because of its moisture binding capacity in aliphatic cosmetic creams, lotions, emulsions, body and face oils for dry skin care as well as for decorative cosmetics like lipsticks. Vitamin E is also successfully applied for various skin diseases.

Very much importance is attached to vitamin E in the food industry, too. Vitamin E is an important lipid-soluble antioxidant which has many positive physiological properties besides its vitamin character.

The term 'antioxidant' describes the capability of molecules neutralizing so called radicals. Thus antioxidants are often called scavengers. Radicals are atoms or molecules which have an unpaired electron in their outer shell. Free radicals also emerge by the normal cell breathing as side products and try to snatch away an electron from other structures for means of completing their outer shell. In this way for example the cell membrane can be damaged. Antioxidants and thus also vitamin E 'deactivate' the free radicals by giving off an electron and in this way protect the cells from 'oxidative stress'.

Cyclodextrins

Cyclodextrins are circular molecules produced by the enzymatic decomposition of starch and they belong to the group of oligosaccharides and consist of 6 to 8 glucose units. The interesting point about cyclodextrins is their cylindrical structure and the resulting properties and application possibilities. The polar OH groups of the individual glucose units are on the outside of the cylinder due to their steric arrangement. The outside is hydrophilic, whereas the inside of the cylinder is non polar and thus hydrophobic (resp. lipophilic).

The cavities of the cyclodextrins (host) can take in 'guest molecules' and release them again. The chemist calls this phenomenon host-guest-chemistry. Guests are all those molecules which could fit into the cavity and are non polar enough to interact with the lipophilic cavity surface.

By this complexation the properties of the locked in molecules change. For example an increase of the water solubility of non polar organic compounds or decrease of sightly volatile substances are obtained through complexation with cyclodextrins, but also an increase of the stability of the locked in substances to light, oxygen and heat.

Altogether the complexation through cyclodextrins has been researched only to a small extent, although cyclodextrins have been marketed for some time now for means of odour absorption (antismell finish). Knowledge about which substances can actually be complexed, is still very fragmentary and quite some more fundamental research will be necessary in this field.

Cyclodextrin-Vitamin-E Complex

Vitamin E being a lipidsoluble substance is virtually predestined for complexation with cyclodextrines. Y-cyclodextrin (8 glucose units) has proven to be a particularly suitable 'active substance'. Examinations have shown that a 2:1 complex consisting of Y-cyclodextrin and vitamin E offers many more advantages in terms of stability than a 1:1 complex.

The antioxidative potential of vitamin E is based on the reactivity of the chromanoxyl radical. The main task of the cyclodextrine is to surround the ring system of the vitamin E molecule (benzopyran-6-ol) and continue to stabilize it.

In this stabilized 'packaging', vitamin E is excellently suitable for Wellness finishes of textiles worn close to the body and these products can be purchased as 'NouWell E' from CHT R Beitlich GmbH.

Fixation and proof of CD vitamin E complex on textile surfaces

As the CD vitamin E complex does not show any substantivity, only those processes are to be considered where the product application can be controlled like for example by padding, spraying, coating or printing. For permanent fixation of the complex, reactive polyurethanes have proven to be advantageous for the following reasons:

• free from formaldehyde
• soft handle
• good permanence
• applicable on all types of fibres.

Fixation of the complex is physical and particularly on CEL and WO chemical (reaction with -OH, -NH2-groups). Fixation of the charged cyclodextrins with reactant crosslinking agents is also be possible, but then only for application on CEL fibres.

The qualitative proof of vitamin E on the textile can be done through a dyeing reaction at which the reductive properties of vitamin E are taken advantage of.

1. Dripping on a FeCl3-solution onto the finished textile. In the presence of vitamin E the Fe3+-Ion is reduced to Fe2+. 2. Dripping on a dipyridyl solution. Dipyridyl forms with Fe2+ions a red chelate complex.

By means of this Redox reaction vitamin E can be easily and safely seen on the fabric with the restriction that this of course can only be done on white or pastel shaded fabric.

(To be continued)

(Mr Zyschka and Dr Bruckmann are with CHT R Beitlich GmbH, Tubingen. Dr Kammerer is with Eberhard-Karls-Universitat Tubingen and Mr Schreiber is with ITV Denkendorf).