Skin substitutes in acute burns

Overview

Skin substitutes encompass a range of products from temporary biologic dressings to engineered dermal regeneration templates, designed to bridge or supplement autologous skin grafting when available donor skin cannot keep pace with wound burden. In patients with extensive burns and limited donor sites, wound closure becomes the rate-limiting step in recovery. Dermal templates improve long-term scar quality by providing a scaffold for organized collagen deposition, while temporary biologic dressings serve as wound coverage until definitive closure.

Dermal regeneration templates

Development and science

The conceptual foundation for skin substitutes arose from the recognition that dermis, once destroyed, does not regenerate spontaneously. Yannas, Orgill, and Burke ^[1] described the development of a collagen-glycosaminoglycan dermal regeneration template in the 1970s, prompted by the survival of massive burn patients whose wounds could not be closed with autograft alone. Their work established the physicochemical properties critical to dermal regeneration: pore size, degradation rate, and cross-link density of the collagen scaffold. The resulting template -- later commercialized as Integra -- induces formation of a neodermis that can be covered with an ultra-thin epidermal autograft, reducing donor site morbidity and improving long-term scar quality compared with split-thickness skin grafts applied directly to excised wound beds.

Clinical evidence

The multicenter postapproval trial reported by Heimbach et al. ^[2] evaluated Integra in 216 burn patients across 13 centers with a mean total body surface area burned of 36.5% (range 1-95%). The template was applied to freshly excised wounds, and within 2-3 weeks a vascularized neodermis formed. Integra take rate was 76.2% (median 95%), and the subsequent thin epidermal autograft take rate was 87.7% (median 98%). Invasive infection at Integra sites occurred in 3.1% of cases. This study established Integra as a viable option for large burns where donor skin is insufficient for conventional grafting.

Product comparisons

Truong et al. ^[6] compared dermal substitutes in a nude mouse full-thickness wound model, implanting AlloDerm, Integra, and Dermagraft into standardized wounds. All three reduced wound contracture compared with ungrafted controls at 4 weeks, but Integra demonstrated the most organized collagen architecture histologically. AlloDerm showed the fastest initial incorporation. These preclinical data support the clinical observation that dermal scaffolds improve wound quality, though product-specific differences exist.

Product classification and selection

Kagan et al. ^[3] convened an expert panel white paper on surgical management of the burn wound and use of skin substitutes. The panel reviewed the available products and clinical evidence, establishing consensus recommendations for product selection based on wound characteristics, available donor sites, and anatomic location. The white paper emphasized that skin substitutes should be viewed as tools within the reconstructive armamentarium rather than replacements for autografting.

Nyame, Chiang, and Orgill ^[4] provided a comprehensive review of clinical applications of skin substitutes, categorizing them by composition (epidermal, dermal, composite) and permanence (temporary, semi-permanent, permanent). They noted that dermal substitutes improve scar quality in deep burns by providing a scaffold for organized collagen deposition rather than the disordered fibrosis seen with grafting onto bare fascia. The authors emphasized that optimal outcomes require meticulous wound bed preparation and infection control, as substitutes are particularly vulnerable to bacterial colonization.

Schulz, Tompkins, and Burke ^[7] reviewed the landscape of artificial skin products, describing temporary coverings (xenografts, allografts, synthetic membranes) and permanent replacements (dermal templates, cultured skin). They emphasized the distinction between biologic dressings that serve as temporary wound coverage and engineered substitutes that participate in tissue regeneration.

Biomaterial science

Sheikholeslam et al. ^[5] evaluated natural polymers (collagen, chitosan, hyaluronic acid), synthetic polymers (polyglycolic acid, polylactic acid), and composite scaffolds. They identified key material properties -- porosity, mechanical strength, degradation kinetics, and cell compatibility -- that determine clinical performance. The review highlighted emerging approaches including electrospun nanofiber scaffolds and 3D-bioprinted constructs, though these remain investigational.

Temporary biologic dressings

Demling ^[8] reported on Biobrane for scald management. Because scalds are typically superficial to mid-second-degree injuries with viable dermis, Biobrane adheres well and provides mechanical and biochemical wound closure. The author reported decreased pain, reduced dressing changes, and faster healing compared with topical antimicrobials for this specific wound depth. Biobrane is not appropriate for deeper injuries requiring excision and grafting.

Pruitt and Levine ^[13] characterized biologic dressings and their mechanical and physiologic effects: protecting the wound, maintaining microbial control, and hastening wound maturation. They evaluated synthetic alternatives modeled after biologic dressings and found that unilaminate synthetic membranes were ineffective on full-thickness wounds but bilaminate constructs incorporating a dermal analog showed promise.

Cultured skin and tissue engineering

Sheridan and colleagues [9, 10] reviewed the role of skin substitutes in burns across two publications spanning several years, documenting the evolution from early biologic dressings through engineered dermal-epidermal composites. They noted that the clinical role of substitutes had expanded from temporary coverage to include dermal regeneration and, in select cases, definitive closure.

Boyce and Warden ^[11] described principles and practices for cultured skin substitutes (CSS) prepared from autologous keratinocytes and fibroblasts seeded onto collagen-glycosaminoglycan substrates. CSS generates epidermal barrier and basement membrane in the laboratory and restores tissue function and structure after transplantation. While CSS remains technically demanding and expensive, it offers a path to definitive closure in patients with massive burns and minimal donor sites.

Garfein, Orgill, and Pribaz ^[12] reviewed tissue-engineered constructs more broadly, noting that successful skin replacement requires integration of epidermal, dermal, and vascular components. They discussed composite constructs under development that combine living cells with biodegradable scaffolds to produce more physiologically complete skin replacements.

Indications and appropriate use

Lacey et al. ^[14] demonstrated that intermediate skin substitutes are unnecessary in small burns under 10% TBSA. In 100 consecutive patients, direct autografting without an intermediate biologic dressing achieved equivalent outcomes with fewer operative steps and lower cost. This study underscores that skin substitutes should be deployed where they add clinical value -- large burns, limited donors, critical anatomy -- rather than reflexively.

Demling and DeSanti ^[15] compared topical antibiotics versus a biologic skin substitute (Transcyte) for mid-partial-thickness facial burns. The skin substitute group had significantly less pain, fewer dressing changes, and faster healing. For facial burns where cosmetic outcome is paramount and the wound bed is favorable, biologic substitutes can simplify care while improving patient experience.

Controversies and Evidence Gaps

Cost-effectiveness remains the dominant barrier to wider adoption of dermal regeneration templates. Integra and similar products carry significant material costs, and the two-stage approach (template application followed by epidermal autograft) adds an operative procedure compared with single-stage autografting. Head-to-head cost-effectiveness analyses controlling for downstream scar revision and rehabilitation costs are lacking.

Optimal product selection is largely empiric. While preclinical comparisons like Truong et al. ^[6] suggest histologic differences between products, there are no large randomized trials comparing commercially available dermal substitutes in matched burn populations. Single-stage approaches that combine dermal scaffolds with immediate thin autograft overlay are being explored but remain investigational in most centers.

The evidence base for cultured skin substitutes is limited by small sample sizes, high cost, and the technical challenge of cell culture. Whether these products will become scalable and cost-effective for routine clinical use remains uncertain.

References

[1] Yannas IV et al. (2011). Template for skin regeneration. PMID: 21200274 [2] Heimbach DM et al. (2003). Multicenter postapproval clinical trial of Integra dermal regeneration template for burn treatment. PMID: 12543990 [3] Kagan RJ et al. (2013). Surgical management of the burn wound and use of skin substitutes: an expert panel white paper. PMID: 23446645 [4] Nyame TT et al. (2014). Clinical applications of skin substitutes. PMID: 25085091 [5] Sheikholeslam M et al. (2018). Biomaterials for Skin Substitutes. PMID: 29271580 [6] Truong ATN et al. (2005). Comparison of dermal substitutes in wound healing utilizing a nude mouse model. PMID: 16921409 [7] Schulz JT et al. (2000). Artificial skin. PMID: 10774462 [8] Demling RH (1995). Use of Biobrane in management of scalds. PMID: 7673318 [9] Sheridan RL et al. (2001). Skin substitutes in burns. PMID: 11270356 [10] Sheridan RL et al. (1999). Skin substitutes in burns. PMID: 10208382 [11] Boyce ST et al. (2002). Principles and practices for treatment of cutaneous wounds with cultured skin substitutes. PMID: 11975935 [12] Garfein ES et al. (2003). Clinical applications of tissue engineered constructs. PMID: 14621297 [13] Pruitt BA et al. (1984). Characteristics and uses of biologic dressings and skin substitutes. PMID: 6365034 [14] Lacey AM et al. (2020). Intermediate Skin Substitutes Are Unnecessary in Small (<10% TBSA) Burns. PMID: 32485731 [15] Demling RH et al. (1999). Management of partial thickness facial burns (comparison of topical antibiotics and bio-engineered skin substitutes). PMID: 10323611