Cultured skin refers to human skin cells or tissue grown in a controlled laboratory setting. This technology developed primarily to address the immense need for functional skin tissue when a person suffers extensive damage, such as from severe burns. By replicating the natural environment of the skin cells, scientists can take a tiny sample of healthy tissue and multiply it significantly. The resulting bio-engineered tissue provides a means to permanently replace lost skin, which is often not possible using traditional grafting methods alone.
The Cultivation Process
The process of creating cultured skin begins with a small, healthy biopsy taken from the patient or a donor. This tissue sample contains the two primary cell types needed for skin structure: keratinocytes, which form the protective outer layer (epidermis), and fibroblasts, which create the structural foundation (dermis). The cells are isolated from the biopsy using enzyme solutions.
Once isolated, the cells are transferred into a specialized culture medium rich with nutrients and growth factors to promote rapid multiplication. Keratinocytes are often grown on a layer of feeder cells to stimulate their growth and differentiation into sheets. Fibroblasts are also multiplied and may be seeded onto a collagen-based matrix to form an artificial dermal layer.
The final cultured product can be a single layer of keratinocytes, known as a Cultured Epithelial Autograft (CEA), or a more complex, multi-layered construct that includes both the epidermal and dermal components. To create a full-thickness model, the keratinocytes are layered on top of the fibroblast-seeded matrix and raised to the air-liquid interface. This exposure to air stimulates the cells to stratify and differentiate, mimicking the multi-layered structure of native human skin.
Therapeutic Applications for Skin Repair
The most direct and life-saving application of cultured skin is in the treatment of extensive deep-partial and full-thickness burn injuries. For patients with burns covering a large percentage of their body, there is often not enough healthy skin left for traditional split-thickness skin grafting. Culturing the patient’s own cells, known as an autologous graft, allows surgeons to generate enough epidermal tissue from a minimal donor site to cover massive wounds.
These Cultured Epithelial Autografts (CEA) provide a permanent covering, but they are thin and lack the underlying dermal structure, which can lead to fragility and poor mechanical strength. Surgeons often apply the cultured epithelial sheets over an acellular dermal matrix or a dermal substitute to provide a better foundation and improve the graft’s long-term function. Cultured skin also extends to chronic wounds, such as large, non-healing ulcers, where the application of cultured cells can stimulate the wound bed to close.
Donor cells can be used to create an allogeneic graft, which is applied earlier to temporarily cover the wound and prevent infection and fluid loss. While allogeneic grafts are eventually rejected by the patient’s immune system, they provide immediate, biological coverage during the weeks required to culture the patient’s own autologous skin. More advanced cultured skin substitutes are engineered to include both autologous keratinocytes and fibroblasts, creating a dermo-epidermal construct that more closely resembles natural skin and results in less scarring.
Using Cultured Skin for Research and Testing
Beyond clinical treatment, cultured skin models serve as powerful laboratory tools for research and safety testing. Three-dimensional, full-thickness skin constructs are used in toxicology studies to test the irritancy and corrosive potential of industrial chemicals and household products. By observing the cellular response of the cultured tissue, researchers can accurately predict how a substance might affect human skin.
The cosmetics and pharmaceutical industries use these bio-engineered skin models to evaluate the safety of ingredients and the efficiency of drug delivery. These models allow studies of how well a topical drug or cosmetic compound penetrates the skin layers, a process known as drug permeability testing. Researchers can also use cultured skin models to study the mechanisms of genetic skin diseases.
Scientists can grow and maintain diseased tissue in vitro from patients with specific skin disorders. This allows them to model complex conditions like Epidermolysis Bullosa or Psoriasis, providing a platform to test new therapies and understand the progression of the disease. This technology provides a highly relevant human-based system for accelerating the development of new treatments and reducing reliance on traditional testing methods.