Bioengineered Skin Substitutes for Wound Treatment

What Are Bioengineered Skin Substitutes?

Bioengineered skin substitutes are advanced wound care products designed to replace damaged or missing skin. Unlike traditional wound dressings, these substitutes actively participate in the healing process by providing structural support and biological signals that promote tissue regeneration. They are laboratory-created products that mimic the structure and function of human skin to various degrees.

These innovative products are typically composed of:

• A dermal component (mimicking the deeper layer of skin)
• An epidermal component (mimicking the outer layer of skin)
• Living cells, growth factors, and/or scaffolding materials

How Bioengineered Skin Substitutes Work

Bioengineered skin substitutes promote wound healing through several mechanisms:

1. Providing a Physical Barrier: They protect the wound from external contaminants and fluid loss.
2. Offering Structural Support: They provide a scaffold or matrix for cell migration and attachment.
3. Delivering Biological Signals: Many contain growth factors, cytokines, and other bioactive molecules that stimulate healing.
4. Cell Delivery: Some products contain living cells (fibroblasts, keratinocytes) that integrate into the wound and facilitate healing.
5. Modulating Inflammation: They can help regulate the inflammatory response for optimal healing.
6. Encouraging Vascularization: They promote the development of new blood vessels in the healing tissue.

When applied to a properly prepared wound bed, these substitutes integrate with the patient’s tissue and eventually get replaced by the patient’s own cells, leading to regeneration rather than simple repair with scar tissue.

Goals of Bioengineered Skin Substitute Therapy

The primary goals of treatment with bioengineered skin substitutes include:

• Accelerated Wound Closure: Faster healing compared to conventional treatments
• Improved Quality of Healing: Reduced scarring and better functional outcomes
• Reduced Infection Risk: Creating a protective barrier against pathogens
• Pain Reduction: Many patients report decreased pain after application
• Prevention of Amputation: Particularly important for diabetic foot ulcers
• Improved Quality of Life: Faster return to normal activities
• Cost Efficiency: Despite higher initial costs, overall treatment costs can be reduced through faster healing and fewer complications

Duration of Treatment

The duration of treatment with bioengineered skin substitutes varies depending on several factors:

• Wound Type and Size: Larger, deeper wounds generally require longer treatment
• Patient Factors: Age, underlying conditions, nutritional status, etc.
• Type of Substitute Used: Different products have different application schedules

Typical treatment protocols involve:

• Initial Assessment and Wound Preparation: 1-2 weeks
• Application of Substitute: Single application for some products; weekly applications for 4-12 weeks for others
• Follow-up Care: Weekly monitoring for several weeks after application
• Complete Healing: Can range from 6 weeks to 6 months depending on wound severity

Most chronic wounds show significant improvement within 4-12 weeks of starting treatment with bioengineered skin substitutes, though complex wounds may require multiple applications or longer treatment periods.

What to Expect During Treatment

Before Treatment

• Comprehensive wound assessment
• Wound bed preparation (removal of dead tissue, control of infection)
• Optimization of patient factors (blood sugar control, nutrition, etc.)

During Application

• Minimal discomfort during the procedure
• Application is typically performed in a clinical setting
• The substitute is measured, cut to fit the wound, and secured in place

After Application

• Secondary dressings will be applied over the substitute
• Limited mobility may be recommended to protect the substitute
• Regular follow-up appointments to monitor progress

Signs of Progress

• Decreased wound size
• Reduced drainage
• Development of healthy granulation tissue
• Advancing wound edges
• Pain reduction

Potential Challenges

• Infection can compromise the effectiveness of the substitute
• Some wounds may require multiple applications
• Underlying conditions must be managed for optimal results

Types of Bioengineered Skin Substitutes

Acellular Products

• Composed of structural proteins and growth factors without living cells
• Examples: AlloDerm®, Integra®, Oasis®

Cellular Products

• Contain living cells within a matrix
• Examples: Apligraf®, Dermagraft®, OrCel®

Epidermal Only

• Replace only the outer layer of skin
• Examples: EpiCel®, MySkin®

Dermal Only

• Replace only the deeper layer of skin
• Examples: Hyalomatrix®, TransCyte®

Composite (Dermal and Epidermal)

• Replace both layers of skin
• Examples: Apligraf®, StrataGraft®

Candidates for Bioengineered Skin Substitute Therapy

This advanced therapy is particularly beneficial for:

• Diabetic foot ulcers
• Venous leg ulcers
• Pressure ulcers
• Burns
• Surgical wounds
• Traumatic wounds that fail to heal with conventional treatment

Summary

Bioengineered skin substitutes represent a significant advancement in wound care, offering hope for patients with difficult-to-heal wounds. By providing structural support, biological signals, and sometimes living cells, these products can dramatically improve healing outcomes. While treatment duration varies based on wound characteristics and patient factors, most patients can expect significant improvement within 4-12 weeks of beginning therapy.