6. Plant Fibres Used as Surgical Dressings: A Complete Guide for Pharmacy Students

PLANT FIBRES AND SURGICAL MATERIALS: A TEACHER’S COMPREHENSIVE GUIDE

Welcome, future pharmacists and healthcare professionals!

As a pharmacy educator with years of experience teaching pharmacognosy, I have always emphasized that plant and animal fibres play a crucial role in pharmacy and surgery. They are widely used because of their absorbency, softness, purity, and biocompatibility. In pharmacognosy, cotton, silk, wool, and regenerated fibres play an important role in surgical dressings, while surgical catgut and ligatures are widely used as suturing materials. Understanding these materials is essential for pharmacy students to appreciate their applications in wound care and surgical procedures.

In this comprehensive guide, I will take you through the various plant fibres and surgical materials used in pharmacognosy. We will explore their biological sources, chemical constituents, characteristics, and therapeutic applications. By the end of this article, you will have a thorough understanding of how natural fibres contribute to surgical practice. Let us begin.

COTTON

Cotton is one of the most important and widely used plant fibres in surgical dressings. It is valued for its softness, absorbency, and non-irritant nature, making it ideal for wound care applications.

Biological Source

Cotton is obtained from the hairs of various species of the genus Gossypium, belonging to the family Malvaceae. The hairs are epidermal outgrowths from the seed coat. The most commonly cultivated species include Gossypium herbaceum, Gossypium arboreum, Gossypium hirsutum, and Gossypium barbadense.

Chemical Constituents

Cotton is composed primarily of cellulose, which makes up about 95% of the fibre. The remaining 5% consists of hemicellulose, pectin, waxes, and other minor components. The high cellulose content gives cotton its strength, absorbency, and softness. The purity of cotton fibres is essential for their use in surgical dressings, as impurities can cause irritation or infection.

Characteristics

• Softness: Cotton fibres are soft and gentle on the skin, making them suitable for wound contact.
• Absorbency: Cotton is highly absorbent, capable of absorbing up to 20-25 times its own weight in water.
• Non-irritant: Pure cotton is non-allergenic and does not irritate the skin.
• Biocompatible: Cotton is well-tolerated by the body and does not cause adverse reactions.

Uses of Cotton

• Absorbent Cotton and Bandages: Used for cleaning wounds, applying medications, and covering injuries.
• Wound Cleaning: Cotton swabs and balls are used for cleaning wounds and applying antiseptics.
• Orthopedic Padding: Used as padding under casts and splints to prevent pressure sores.
• Surgical Dressings: Cotton gauze and pads are essential components of wound dressings.

SILK

Silk is a natural protein fibre produced by certain insects. It is highly valued in surgery for its strength, smoothness, and flexibility. Silk has been used for centuries as a suturing material and remains popular in many surgical procedures.

Biological Source

Silk is obtained from the cocoons of the silkworm, Bombyx mori. The silkworm spins a cocoon from a continuous silk fibre to protect itself during metamorphosis. The fibre is composed of two proteins: fibroin (the core) and sericin (the outer coating).

Chemical Constituents

• Fibroin: The structural protein that gives silk its strength and flexibility.
• Sericin: The gum-like protein that coats the fibroin fibres and provides protection.

Characteristics

• Strength: Silk is one of the strongest natural fibres, with excellent tensile strength.
• Smoothness: Silk fibres are smooth and gentle on tissues, reducing trauma during suturing.
• Flexibility: Silk is flexible and easy to handle, making it ideal for delicate surgical procedures.
• Knot Strength: Silk holds knots securely, preventing slippage during surgery.

Uses of Silk

• Non-absorbable Sutures: Silk is used as a non-absorbable suture material in various surgical procedures.
• Ophthalmic and Dental Surgery: Used in delicate procedures where fine sutures are required.
• Excellent Knot Strength: Silk sutures are known for their knot security, which is essential for wound closure.

WOOL

Wool is an animal fibre obtained from sheep. It is used in medical applications for its elasticity, moisture-absorbing properties, and cushioning effect.

Biological Source

Wool is obtained from the fleece of sheep, primarily Ovis aries. The fibre is composed of the protein keratin, which gives wool its strength and elasticity.

Chemical Constituents

• Keratin: A fibrous protein that provides strength, elasticity, and moisture absorption.

Characteristics

• Elasticity: Wool fibres are highly elastic and can stretch without breaking.
• Moisture-Absorbing: Wool can absorb up to 30% of its weight in moisture without feeling wet.
• Insulating: Wool provides thermal insulation, which can be beneficial in certain medical applications.

Uses of Wool

• Medicated Wool Pads: Used to apply medications to wounds and skin conditions.
• Cushioning Material: Used as padding to protect wounds and prevent pressure sores.
• Prevents Skin Friction: Wool can be used to reduce friction between skin and medical devices.

REGENERATED FIBRES

Regenerated fibres are manufactured fibres made from natural cellulose. They are used as cost-effective alternatives to natural fibres in surgical dressings and sanitary products.

Examples

• Rayon: A regenerated cellulose fibre made from wood pulp or cotton linters.
• Viscose: A type of rayon made from cellulose xanthate.

Source

Regenerated fibres are produced from processed cellulose derived from wood pulp, cotton linters, or other plant sources. The cellulose is chemically treated and extruded to form fibres.

Characteristics

• Smoothness: Regenerated fibres are smooth and uniform, making them comfortable for wound contact.
• Uniformity: Manufactured fibres have consistent properties, ensuring reliable performance.
• Absorbency: These fibres are highly absorbent and suitable for wound dressings.

Uses of Regenerated Fibres

• Surgical Dressings: Used in gauze, pads, and other wound care products.
• Sanitary Products: Used in pads, tampons, and other hygiene products.
• Cost-Effective Alternative: Provides a more affordable option compared to natural fibres.

SURGICAL CATGUT

Surgical catgut is a natural absorbable suture material obtained from the intestines of animals. It is widely used in internal suturing where the material is expected to be absorbed by the body.

Biological Source

Surgical catgut is obtained from the small intestines of sheep (Ovis aries) or goats. The intestinal submucosa is processed to produce the suture material.

Chemical Constituents

• Collagen: The primary protein component of catgut, which is gradually absorbed by the body.

Types of Catgut

• Plain Catgut: Absorbed rapidly within 7-10 days. Used in tissues that heal quickly.
• Chromic Catgut: Treated with chromium salts to slow absorption (14-21 days). Used in tissues that require longer support.

Uses of Surgical Catgut

• Internal Sutures: Used to close internal tissues and organs.
• Gynecology and GI Surgery: Commonly used in gynecological and gastrointestinal procedures.
• Dissolvable Stitches: Provides a convenient option for sutures that do not require removal.

LIGATURES

Ligatures are materials used to tie blood vessels and control bleeding during surgery. They are essential for haemostasis and surgical precision.

Materials Used for Ligatures

• Silk: Strong and flexible, used in various surgical procedures.
• Catgut: Absorbable, used for internal ligatures.
• Cotton: Used as a non-absorbable ligature material.
• Nylon, Polyester: Synthetic materials used for ligatures.

Functions of Ligatures

• Stops Bleeding: Ligatures are used to tie off blood vessels to control haemorrhage.
• Holds Tissues During Surgery: Used to secure tissues and maintain surgical field clarity.

A TEACHER’S PRACTICAL INSIGHTS

Over my years of teaching, I have developed a few key insights about plant fibres and surgical materials that I always share with my students:

• Understanding the properties of different fibres helps in selecting the right material for specific surgical applications.
• Absorbability is a critical factor in choosing suture materials. Absorbable sutures are used for internal tissues, while non-absorbable sutures are used for skin closure.
• The purity and biocompatibility of fibres are essential to prevent infection and promote wound healing.
• Regenerated fibres offer a cost-effective alternative to natural fibres without compromising quality.

FREQUENTLY ASKED QUESTIONS (FAQs)

1. What is the biological source of cotton?

Cotton is obtained from the hairs of various species of Gossypium.

2. What is the main chemical constituent of cotton?

Cotton is composed primarily of cellulose, making up about 95% of the fibre.

3. What is silk used for in surgery?

Silk is used as a non-absorbable suture material in various surgical procedures, including ophthalmic and dental surgery.

4. What is the difference between plain and chromic catgut?

Plain catgut is absorbed rapidly within 7-10 days, while chromic catgut is treated with chromium salts to slow absorption to 14-21 days.

5. What are regenerated fibres?

Regenerated fibres are manufactured fibres made from natural cellulose, such as rayon and viscose.

6. What are ligatures used for?

Ligatures are used to tie blood vessels and control bleeding during surgery.

7. Why is absorbency important in surgical dressings?

Absorbency is important because it allows the dressing to absorb wound exudate, keeping the wound clean and promoting healing.

SUMMARY

Plant and animal fibres play a crucial role in surgical dressings and suturing materials. Cotton, silk, wool, and regenerated fibres are widely used because of their absorbency, softness, purity, and biocompatibility. Surgical catgut and ligatures are essential for suturing and haemostasis in surgical procedures.

Cotton is valued for its absorbency and non-irritant nature. Silk is used for its strength and smoothness. Wool provides elasticity and moisture absorption. Regenerated fibres offer cost-effective alternatives. Surgical catgut is an absorbable suture material derived from animal intestines, and ligatures are used to control bleeding during surgery.

Understanding these materials is essential for pharmacy students to appreciate their applications in wound care and surgical procedures.

As I always tell my students: “Natural fibres are the foundation of surgical care. They have been used for centuries and remain essential in modern medicine.”

REFERENCES & FURTHER READING

• Evans, W. C. (2009). Trease and Evans Pharmacognosy (16th ed.). Elsevier.
• Kokate, C. K., Purohit, A. P., & Gokhale, S. B. (2014). Pharmacognosy (50th ed.). Nirali Prakashan.
• World Health Organization (WHO). (2023). Guidelines on Surgical Dressings and Materials. Retrieved from WHO Official Website.
• Indian Pharmacopoeia Commission (IPC). (2023). Surgical Materials Standards. Retrieved from IPC Official Website.
• Government of India. (1948). The Pharmacy Act, 1948. Ministry of Health and Family Welfare.

Disclaimer: This article is for educational purposes only and does not constitute medical or legal advice. Always consult qualified healthcare professionals and regulatory authorities for professional and legal matters.