Magnetosomes for use in a sequential laser radiation medical treatment, wherein the magnetosomes are administered to a body part of an individual. In a first step, the magnetosomes are irradiated by a laser radiation, and in a second step, the magnetosomes are irradiated by a laser radiation of lower power than in the first step or no laser irradiation of the magnetosomes is performed. The sequence of the first step and second step is repeated at least once.