Advanced Textiles for Wound Care

S. Rajendran

• Publisher: Woodhead Publishing
• Year: 2018
• eBook ISBN: 9780081021934
• Edition: 2
• Topic: Technology & Engineering
• Subtopic: Materials Science
• Index: Technology & Engineering

Advanced Textiles for Wound Care, Second Edition, provides a detailed review of how textiles are incorporated into wound care applications, also explaining the importance and suitability of using textiles on different wound types. It is an interdisciplinary book which directly links textile technology with advances in wound care. The book discusses new developments and techniques related to antimicrobial dressings, the use of biopolymers in infection control management, advanced dressings for managing cavity and cancerous wounds, and the application of nanofibers and novel textile structures in scaffolds, among other new areas. This updated edition also reflects recent changes in regulatory affairs.The book is essential reading for manufacturers, designers, scientists and producers of wound care materials. It is a valuable resource for professionals within the medical sector, as well as those in academia, enabling materials scientists and engineers in both academia, and at medical device companies, to stay abreast of new technology.- Provides a comprehensive introduction to wound care, from the different types of wound and wound healing mechanisms, to the importance of testing in relation to wound care- Analyzes the application of textiles to wound healing, covering minor wounds, burns, ulcers and other deep skin wounds- Reviews the current use of smart textiles for wound care, including drug delivery dressings and textile-based scaffolds for tissue engineering

1

Wound management and dressings

Authors of the chapter: Shahzad Ather¹, and K.G. Harding^{2 1}Wound Healing Research Unit, Department of Surgery, Cardiff University, Cardiff, United Kingdom ²Cardiff University, Cardiff, United Kingdom

Editor of the chapter: S.J. Tate^{1,2 1}Cardiff University, Cardiff, United Kingdom ²Welsh Wound Innovation Centre, Wales, United Kingdom

Abstract

This chapter describes the various types of wounds and their mechanisms of healing. Factors affecting the management of wound healing are outlined. A nonhealing chronic wound is usually the result of a combination of issues. Wound management should therefore be multifactorial and aimed at correcting the underlying abnormalities. Options for treatment are described, with no single treatment being universally effective owing to the multiple molecular and cellular events involved. A combination of different therapies is usually required. Future trends include application of gene therapy and stem cell therapy.

Keywords

Chronic wounds; Wound healing; Wound management

1.1. Introduction

A wound is defined as a break in the epithelial integrity of the tissues. This disruption can be deeper and involve subepithelial tissues including dermis, fascia and muscle. Wounds can be caused by physical trauma where the skin is torn, cut or punctured (an open wound) or where a blunt force trauma causes a contusion (a closed wound). They may also be the result of a disease process affecting the skin. The history of wound care spans from prehistory to modern medicine and has evolved from simple wound covers ranging from vinegar-soaked dressings, through topical antibiotics to topically applied growth factors [1]. Even during early historical periods several factors were noted that speeded up or assisted the process of healing. The necessity for hygiene, the prevention of bleeding and, later on, the germ theory of disease paved the way for modern wound management.

1.2. Types of wound

Wounds can be classified in many ways. Important factors in the description of a wound include the aetiology of the wound (e.g., pressure, trauma, ischaemia, heat, friction, surgery, etc), the timing and chronicity, the level of contamination, and the depth of injury to the skin and underlying tissues. These factors will all affect the management of the wound.

1.2.1. Describing the aetiology of a wound

Some commonly used nomenclature that alludes to the aetiology of a wound are as follows:

• Abrasion: A superficial epithelial wound caused by friction or scraping.
• Incision: A wound made by a clean, sharp-edged object. This may be intentional, such as during surgery, or unintentional, such as an injury from broken glass.
• Laceration: A break in the skin that is the result of trauma exceeding the intrinsic tissue strength, for example, a skin tear after blunt trauma to the scalp.
• Contusion: Tissue trauma from a blunt injury or blast injury where the overlying skin remains intact, although it may later become nonviable.

1.2.2. Acute and chronic wounds

An acute wound may be defined as a recent wound, of any aetiology, that is expected to progress through the normal sequential phases of wound healing. In terms of biology, a chronic wound is one that is failing to progress through the stages of wound healing in an anticipated time frame [2]. Clinically, however, the word ‘chronic’ may be used to describe a wound that is more than 5 days old and therefore expected to be colonised with bacteria and unsuitable for primary closure without debridement [3].

1.2.3. Level of contamination

Wounds may be classified according to the level of contamination [4].

Class I/clean:	An uninfected operative wound in which no inflammation is encountered and the respiratory, alimentary, genital, or uninfected urinary tract is not entered.
Class II/clean–contaminated:	An operative wound in which the respiratory, alimentary, genital, or urinary tracts are entered under controlled conditions and without unusual contamination.
Class III/contaminated:	Open, fresh, accidental wounds. Operations with major breaks in sterile technique (e.g., open cardiac massage) or gross spillage from the gastrointestinal tract and incisions in which acute, nonpurulent inflammation is encountered.
Class IV/dirty–infected	Old traumatic wounds with retained devitalized tissue and those that involve existing clinical infection or perforated viscera.

1.3. Mechanism of wound healing

The aim of wound healing is the restoration of tissue integrity in order that homoeostatic mechanisms can be re-established and fluid loss and the risk of infection can be minimised. It is a well-orchestrated and complex process, triggered by tissue injury and ending in regeneration or repair. It can be divided into categories based on the anticipated nature of the healing process (see Fig. 1.1).

1.3.1. Healing by primary intention

Wound edges are approximated with sutures, staples or adhesive, leaving no residual discontinuity in the skin. This must be done within hours of occurrence. It enables closure to occur quickly, as minimal tissue is required to repair the defect, and scarring is usually minimal.

1.3.2. Healing by secondary intention

The wound is left open without any formal closure. Healing occurs by reepithelialisation and contraction. This may be necessary because the wound is large, and the edges cannot be reapproximated, or because of the degree of contamination. The size of the defect and amount of disruption in the tissue integrity determines the degree of new tissue matrix and epidermal surface needed for complete closure [5] and therefore the length of time that this will take.

Figure 1.1 Differential wound healing.

1.3.3. Delayed primary/tertiary healing

Wound closure is delayed for several days; this is usually employed for contaminated wounds where a period of cleaning, debridement, and observation is carried out prior to closure or skin grafting.

1.4. Biology of wound healing

Irrespective of the cause, acute wounds should pass through a series of overlapping stages to achieve healing. Studying this process in order to optimise it remains central to wound healing research. Tissue injury sets in motion a cascade of cellular and biochemical activities, involving a variety of blood and parenchymal cells, extracellular matrices (ECMs) and soluble mediators. Four phases are defined; haemostasis, inflammation, proliferation and remodelling. These stages are clinically indistinct and overlap in time. Fig. 1.2 summarises the stages and the important cell types and processes taking place.

1.4.1. Haemostasis

The first step in the process of inflammation is haemostasis, which is characterised by vasoconstriction and coagulation. It starts soon after injury and is usually completed within the first few hours. Disruption of blood vessels and lymphatics exposes the tissue to the blood. The coagulation cascade is activated in conjunction with platelets resulting in the deposition of a haemostatic ‘plug’ [6].

Figure 1.2 Wound biology: phases of wound repair.

The activated platelets release cytokines and gro...

Table of contents

• Cover image
• Title page
• Table of Contents
• The Textile Institute Book Series
• Notices
• List of Contributors
• Preface
• 1. Wound management and dressings
• 2. Testing dressings and wound management materials
• 3. Textile materials and structures for topical management of wounds
• 4. Interactive dressings and their role in moist wound management
• 5. Bioactive dressings to promote wound healing
• 6. Advanced textiles for wound compression
• 7. Antimicrobial textile dressings to manage wound infection
• 8. Novel textiles in managing burns and other chronic wounds
• 9. Drug delivery dressings
• 10. The use of ‘smart’ textiles for wound care
• 11. Composite dressings for wound care
• 12. Textile-based scaffolds for tissue engineering
• 13. The application of collagen in advanced wound dressings
• 14. Speciality dressings for managing difficult-to-heal wounds
• 15. Regulatory bodies and their roles associated with medical devices and wound dressings
• 16. The role of biopolymers and biodegradable polymeric dressings in managing chronic wounds
• 17. The role of nanostructures in various wound dressings
• 18. Advances in fabric structures for wound care
• 19. Application of natural polymers and herbal extracts in wound management
• Index