Dermal Regeneration Photosynthetic Matrix

Safety of the dermal regeneration photosynthetic matrix (DRPM) will be conducted at: 1) Department of Plastic Surgery of Hospital del Salvador, 2) Red UC Christus, and/or 3) Instituto de Neurocirugía (INCA). This safety assessment represents the first objective of this trial, and will be performed in 20 human patients (between 18-65 years old) presenting non-infected acute wounds (confirmed by negative quantitative culture of tissue sample) and homogenous granulation bed. All patients involved in this study will participate only previous approval of the informed consent for the study protocol which has been already accepted by the Research Ethics Committee of the Metropolitan Health Service (approval number: CECSSMO080820018) and each of the affiliated hospitals.

The inclusion criteria of the patients consist of full-thickness skin wounds, homogeneous granulation tissue and negative bacterial count according to quantitative tissue culture. Exclusion criteria will be based on ages under 18 years or over 65 years. Also, patients with autoimmune diseases or immunosuppression will be excluded from the study. Patients with psychiatric disorders that impede decision-making and continue treatment will also be excluded from the treatment, as well as patients with injuries in the face.

Treatment will be performed in two surgical procedures. In the first one, DRPM will be implanted and illuminated with a LED array. Once the photosynthetic scaffold is properly adhered to the wound bed (approximately 21 days), a second surgical procedure will be carried out, where an autologous partial skin graft will be performed on top of the scaffold. In case of a major complication (uncontrollable pain, sepsis, shock), or at the request of the patient, the DRPM will be removed immediately and the standard treatment will be performed for that type of wound. All patients included in the study will be evaluated for local and systemic immune response against DRPM.

Systemic response will be studied by means of hematological, coagulation and biochemical profiles as well as by quantification of plasma cytokines and immune cells in peripheral blood. Hematological profiles will include hematocrit, erythrocytes, hemoglobin, platelets and leukocytes counts, performed by certified clinical laboratory methods. Coagulation tests will include international normalized ratio (INR), prothrombin time (PT) and partial thromboplastin time (PTT). Biochemical profiles will include quantification of blood glucose, creatinine, bilirubin direct and total levels, serum glutamic-oxaloacetic transaminase (SGOT), serum glutamic-pyruvic transaminase (SGPT), alkaline phosphatase and C-reactive protein, as well as clinically relevant enzymatic activities and plasmatic electrolytes (sodium, potassium and chloride). Concentration of inflammatory plasma cytokines (TNF-α, IL-1β, IL-6, IL-8, IL-12p70 and IL-10), as well as the following circulating immune cells: T-cells (CD3+), T-helper cells (CD3+CD4+), cytotoxic T-cells (CD3+CD8+) and their ratio (CD4+/CD8+), B-cells (CD19+) and NK cells (CD16+CD56+) will be quantified. All parameters will be quantified before DRPM implantation (day 0), short-term after implantation (1-3 days), 1 week after implantation and right before autograft procedure. Parameters will be also quantified short-term after autograft (1-3 days), 1 week after autograft and 2 months after autograft.

Additionally, in order to study the local response of DRPM implantation, a biopsy punch will be obtained before (day 0) and 1 week after scaffold implantation, as well as before and 1 week after autografting, and wound regeneration will be evaluated by quantification of cellularization (nuclear staining), presence of macrophages (CD68) and microorganisms (Giemsa) and neovascularization (CD31).

Finally, a final self-evaluation survey will be completed by all patients, where parameters such as pain, itching, burning, light annoyance, smell and general aspect of the wound will be evaluated.

Inclusion criteria

• Full-thickness skin wounds.
• Between 18 and 65 years old
• Non-infected wounds (confirmed by quantitative culture of the tissue sample).
• Homogeneous granulation of wound bed.
• Approval of the informed consent for the study protocol.

Exclusion criteria

• Ages under 18 years or older than 65 years.
• Comorbidities such as autoimmune diseases, immunosuppression, coronary heart disease or occlusive arterial disease.
• Chronic drug and/or alcohol abuse.
• Psychiatric disorders that impede decision-making and continue treatment.
• Patients suffering from an acute pathology other than the skin injury.
• Full-thickness skin wounds in face.