This invention relates magnetosomes in a sequential laser radiation medical or biological or chemical or cosmetic treatment, wherein the magnetosomes are administered to a body part of an individual and:- In a first step, the magnetosomes are irradiated by a laser radiation at a first power, 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, andthe sequence comprising the first step and the second step is repeated at least once.
