Preamble Polymer-drug conjugates have been intensively investigated for several decades, and even though their clinical success still lags behind the promise many researchers have placed in them, they are a mainstay in the fields of polymer therapeutics or nanomedicine. For many in the field, the seminal perspective paper by Helmut Ringsdorf from 1975 marks the beginning of this field of research. With more than one thousand citations, this paper has indubitably affected and inspired generations of researchers in the field, including the author of this translation. However, it is not the first paper describing the concept of polymer-drug conjugates. Some twenty years earlier, Horst Jatzkewitz described in two outstanding articles probably the historically first polymer-drug conjugates, detailed its synthesis, characterization and even first in vivo experiments. The results, carefully re-interpreted through the eyes of a scientist of the 21st century, clearly highlight several issues that need to be taken into consideration when designing polymer-drug conjugates. However, despite the pioneering nature of this paper, it is all but forgotten by the scientific community. In the author’s opinion, Horst Jatzkewitz and these papers clearly did not receive the attention and praise they deserve. Whether this was because these paper were much ahead of it´s time, or because it was published in German language, or for some other reason, we cannot know. However, these papers are, in my opinion, an excellent piece of work that should be known more widely and available to students and experts world-wide, which is why the author decided to translate it. Also, to give some more context and to help understand some outdated terms or concepts, additional comments and explanations are added throughout. I hope that this will help for these papers to receive the attention I believe they deserve.