Use of collagen and negative pressure wound therapy in a diabetic foot ulcer: a case study SINOPSIS: The following case study describes the use of a collagen layer in combination with negative pressure wound therapy in a diabetic foot ulcer, treated in a hospital in Chile. The wound reduced 58% in size in the first 10 weeks of treatment, reaching complete healing in the following 14 weeks. The treatment carried out avoided amputation of the foot of the patient who, at 64 years of age, maintained his independence and quality of life.