What is the Sandwich Method of Wound Dressing
The "sandwich method" or "sandwich-structured" wound dressing refers to a multi-layered composite dressing system with three distinct functional layers designed to manage wound exudate through unidirectional drainage while preventing tissue adhesion and maintaining an optimal healing environment. 1
Structure and Components
The sandwich dressing consists of three engineered layers with specific functions 1:
Outer layer (wound-facing): A superlyophobic (liquid-repelling) layer that allows wound exudate to pass through in one direction via milli-scale channels while preventing backflow 1
Middle layer (absorbent core): A superlyophilic (highly absorbent) gauze layer that captures and holds wound exudate after it passes through the outer layer 1
Inner layer (backing): A lyophobic (moisture-resistant) layer that prevents strike-through of exudate to the external environment 1
Mechanism of Action
The sandwich structure achieves unidirectional fluid management through specific material properties 1:
Wound exudate accumulates at the interface between the dressing and wound surface, gradually deforming until it passes through the superlyophobic outer layer 1
The hierarchical micro/nanostructures on the outer layer surface enable controlled fluid passage while maintaining anti-adhesion properties 1
Once absorbed by the middle gauze layer, the lyophobic backing prevents external contamination and maintains a moist wound environment 1
Clinical Applications and Evidence
This dressing technology has demonstrated significant benefits in experimental wound models, reducing wound infection occurrence and accelerating healing by approximately 20% compared to standard dressings. 1
Key advantages include 1:
- Prevention of tissue tearing during dressing changes due to anti-adhesion properties
- Effective exudate management without wound bed desiccation
- Reduced infection rates through controlled drainage
- Compatibility with adjunctive therapies (can be combined with stem cell supernatant powders for enhanced healing) 1
Important Context for Chronic Wounds
While the sandwich-structured dressing shows promise for acute trauma wounds 1, standard chronic wound management (diabetic foot ulcers, pressure ulcers) should prioritize simple dressings selected based on exudate control, comfort, and cost rather than complex engineered systems. 2
For chronic wounds, evidence-based practice emphasizes 2:
- Regular cleaning with water or saline
- Maintaining a moist wound environment with sterile, inert protective dressings
- Controlling exudate to avoid tissue maceration
- Avoiding antimicrobial dressings unless specifically indicated, as they provide no healing benefit 3, 4
Clinical Pitfall
Do not confuse the research-based "sandwich-structured composite wound dressing" with routine layered dressing techniques used in standard wound care. The sandwich method described in recent literature refers specifically to engineered materials with unidirectional drainage properties 1, not simply applying multiple standard dressing layers sequentially. For most chronic wounds in clinical practice, simpler dressing approaches guided by exudate level remain the evidence-based standard. 2