EPR Spectroscopic Examination of Different Types of Paramagnetic Centers in the Blood in the Course of Burn Healing

Abstract

The multicomponent electron paramagnetic resonance spectra of the blood during healing of skin burned wounds treated with a new generation biodegradable dressings containing poly(lactide-co-glycolide) were analysed. The evolution of different types of paramagnetic centers in the blood with time of healing was determined. The EPR spectra of the blood samples at 230 K temperature were measured at 1, 10, and 21 days after burning of the pig skin. The EPR lines of the following paramagnetic centers: the high-spin Fe³⁺ in methemoglobin (line I), high-spin Fe³⁺ in transferrin (line II), and Cu²⁺ in ceruloplasmin and free radicals (line III) were observed in the X-band (9.3 GHz) spectra of the blood. The multicomponent structure of the EPR spectra of the tested blood samples depended on the time of the healing of the burned wounds. The amount of the high-spin Fe³⁺ in methemoglobin (line I) in the blood decreased after 21 days of the healing of the burned wounds. The amount of the high-spin Fe³⁺ in transferrin (line II) slightly increased after 21 days of therapy with the basis. The amount of Cu²⁺ in ceruloplasmin and free radicals (line III) in the blood was very high after 10 days of therapy. At the first day of the healing of the burned wounds, the highest amount of the high-spin Fe³⁺ in methemoglobin (line I), the relatively lower amounts of the high-spin Fe³⁺ in transferrin (line II), and Cu²⁺ in ceruloplasmin and free radicals (line III) existed in the blood. In the medium phase (after 10 days) of the healing of the burned wounds, the extremely higher amounts of Cu²⁺ in ceruloplasmin and free radicals (line III) appeared in the blood. In the last phase (after 21 days), only the low differences between the amounts of the high-spin Fe³⁺ in methemoglobin (line I), the high-spin Fe³⁺ in transferrin (line II), and Cu²⁺ in ceruloplasmin and free radicals (line III) were observed. The present study may serve as a starting point for the development of a new technique for monitoring molecular complexes containing iron Fe³⁺ (methemoglobin, transferrin) or copper Cu²⁺ ions (ceruloplasmin) and free radicals in the blood during wound healing.