Keratin-based dressings for chronic wounds

What are they curbdressings based on

Keratin is the protein that forms the scales of the skin. New technology is using keratin to cover and protect long-standing wounds or ulcers (especially chronic leg ulcers) to promote healing.

Keratin dressings release keratin peptides in the wound these activate keratinocytes (skin cells) in the wound bed, stimulating them to proliferate and leading to wound healing. Keratin dressings have been reported to reduce the total cost of care and improve quality of life.

Context information

Many wounds remain unhealed despite optimal standard care. For example, in the USA, standard care for diabetic foot ulcers leads to the healing of less than a third of patients in 20 weeks. More than 25 percent of venous Leg ulcers remain unhealed, even after six months of therapy.

In chronic wounds, there is a failure in normal healing processes, which include hemostasis (blood clotting), inflammation, the formation of granulation tissue and reepithelialization of the skin surface.

Various attempts have been made to improve wound dressings, including the use of biological materials such as cells and growth factors.

The role of keratin in wound healing is under investigation. Keratin has traditionally been viewed as a purely physical structure that protects the skin. However, we now know that keratin proteins are also of vital importance for normal wound healing.

Role of keratin in wound healing.

Keratins (KRT) are a family of epidermal proteins made by cells called keratinocytes. They are present on the skin, hair and nail. Keratin is an important component of the skin barrier function.

Curb gene expression marks three keratinocytes phenotypes:

• basal keratinocytes expressing KRT5 and KRT14 proteins
• differentiating keratinocytes expressing the KRT1 and KRT10 proteins
• activated keratinocytes expressing the KRT6, KRT16 and KRT17 proteins.

Activated or functional keratin has bioactive properties that improve wound healing. Wound healing begins with the migration of keratinocytes at the edge of the wound to the wound bed. This leads to the following stages of wound healing: proliferation and migration of fibroblasts, production of collagen and granulation tissue formation.

Keratinocytes do not activate in chronic, non-healing wounds.

Indications for use

Keratin dressings can be used to help heal a variety of wounds and ulcers. For example:

• Venous and arterial leg ulcers
• Diabetic foot ulcers
• Pressure ulcers (pressure ulcers).

• Skin graft donor sites

• First and second degree thermal burns.
• Superficial injuries, cuts, abrasions and surgical wounds.

• Epidermolysis bullosa.

What types of keratin dressings are available?

Keraplast Technologies, LLC, San Antonio, Texas, USA (May 2013) has used the keratin protein extracted from New Zealand sheep wool to make wound dressings. Replicaine ™ Keratin® Functional Advanced Wound Dressings are approved by the regulatory authorities of the US FDA, the European Union, Australia and New Zealand.

Keratin dressings are available in different shapes for different types of wounds.

• Rich in keratin gel/ /ointment It is suitable for dry wounds.
• Keratin matrix dressings are designed for wounds that produce a moderate amount of exudate; These dressings are absorbed into the wound as it heals.
• Multilayer dressings in which the keratin in contact with the wound is backed by polyurethane foam are designed for very exuding wounds.

How do we know that keratin dressings are effective?

To date, no controlled clinical trials of keratin wound dressings have been reported. Available data is based on case series.

Clinical evaluations of chronic wound care keratin dressings conducted at the Nude Maude Wound Clinic in Christchurch in New Zealand have shown a reduction in wound size, confirmed by planimetry and wound photography, in a variety of problematic chronic wounds that do not heal.

• In 23 patients (mean age 74 years; mean wound duration 5.2 years) with chronic, non-healing, venous, arterial and diabetic non-infectious wounds, three keratin bandages (gel, matrix and foam) were evaluated for 3 - months.
• In this study, nurses '91% and patients' 86% indicated a preference for keratin dressings over their previous treatments.
• 71% of wounds classified as non-healing according to established independent criteria, (> 6 months duration,> 5 cm² size) achieved wound closure after the use of keratin dressings, confirmed by planimetry and wound photography, compared to a historical expectation of 13% for this type of wound.
• In a separate case series of 4 patients with epidermolysis bullosa, regular use of keratin dressings over a period of 3 to 6 months resulted in decreased blister rates and improved wound healing rates.

How should keratin dressings be applied?

The following recommendations come from the manufacturer of keratin-based dressings.

• Sterility - Products are recommended for single patient, single use only and should not be used if packaging is damaged.
• Infection control - if the wound is clinically infected, a specialist antimicrobial The dressing should be used to control infection before using keratin dressings.
• Preparation of the wound bed: the wound bed must be cleaned and everything necrotic tissue removed and gently debrided.
• Dressing change: dressings should be changed often enough to remove exudate from the wound and replenish the keratin supply.
• The dressings are designed to reabsorb and deliver keratin over a 4-7 day period, depending on exudate levels and enzyme activity in the wound bed.

Do keratin dressings cause any harm?

To date, no adverse effects have been reported from keratin dressings. They are well tolerated by host tissues and do not provoke immune reactions.