Microstructured composite particles obtainable by a process in which large particles are bonded to small particles, wherein - the large particles have a mean particle diameter in the range from 0.1 µm to 10 mm, - the mean particle diameter of the small particles is at most 1/10 of the mean particle diameter of the large particles, - the large particles comprise at least one polymer, - the small particles comprise at least one calcium salt, - the small particles comprise precipitated calcium carbonate particles having a mean particle size in the range from 0.01 µm to 1.0 mm and/or the large particles comprise at least one absorbable polyester having a number-average molecular weight in the range from 500 g/mol to 1 000 000 g/mol. The composite particles are preferably used as an additive, especially as a polymer additive, as an additive or starting material for the production of components, for applications in medical technology and/or in microtechnology and/or for the production of foamed articles.