Curativos de hidrogel de alginato e extrato de calêndula: avaliação tecnológica e estudo de caso

Abstract

Chronic wounds, such as venous ulcers and diabetic ulcers, have significant challenges to public health, compromising patients' quality of life due to chronic pain, reduced mobility, and social stigmatization, in addition to imposing high costs due to prolonged treatment. This study aimed to produce an alginate hydrogel dressing with calendula extract and evaluate its clinical application in the healing of venous and diabetic ulcers. The dressing was produced by the solvent casting technique, sterilized by gamma radiation, and characterized before and after sterilization for its morphological properties by scanning electron microscopy (SEM), pH, and degree of swelling. The clinical study included two patients: a female patient with a venous ulcer in the lower limb and a male patient with a diabetic ulcer. The study was conducted at the Vascular Surgery Outpatient Clinic of the Regional University Hospital of Ponta Grossa, Paraná, after approval by the UEPG Research Ethics Committee. The study involved applying the dressing for six weeks and evaluating the evolution of the ulcer by monitoring the wound, with measurements of the area using the “Imito measure” software and by histological analysis after the treatment period. The alginate hydrogel with calendula extract was produced on gauze, and the dressings were successfully packaged and sterilized, appearing as yellow-colored impregnated gauze. MEV demonstrated that the hydrogel filled the gauze fibers, but porous regions have kept appearing and also small physical changes caused by sterilization appeared, possibly due to alginate depolymerization. The pH of the dressing is 6.3 and increased slightly to 6.4 with sterilization. The dressing showed a high degree of swelling (600%) with a slight reduction to 500% after sterilization, probably caused by alginate depolymerization. The clinical study showed a reduction in the area of the venous ulcer by approximately 17.7% and 7.6% and of the diabetic ulcer by 35% and 17.5% in the third and sixth weeks of treatment, respectively. Histological images showed areas of granulation tissue in the process of epidermal regeneration, with fibrin deposition and inflammatory infiltrate in both cases, and in the patient with venous ulcer, better tissue repair with neovascularization was observed. Thus, it is concluded that the developed calendula extract hydrogel has promising physicochemical characteristics for use as a dressing, with potential for wound treatment. However, further studies should be conducted with a larger number of volunteers and different treatment protocols, aiming at wound healing.