This study focuses on teachers' training in introducing nanoscience and nanotechnology (NST) topics in school. In the context of a Community of Learners (CoL) in-service teachers, in collaboration with science education researchers, nanoscience researchers and experts from science museums, developed a teaching module in NST topics which integrates socio-scientific issues and the development of exhibits. The aim of this study is to investigate teachers' professional change by focusing on their collegial interactions in the CoL. Video recordings and semi-constructed interviews were used for data collection. The Interconnected Model of Professional Growth (IMPG) was used for data analysis in order to unearth the processes that develop the sequences of teachers' professional change in this context. The findings in this study highlight that teachers' interactions in the CoL change dynamically, as they anticipate to acquire qualified feedback on the emerged challenges of the task. They interact with researchers and experts, so as to bring in balance science-oriented issues with students' perspectives and research-based instructional approaches, primarily in the process of analyzing and clarifying aspects of the module which are innovative to them. During the process of the module's detailed development and implementation, they anticipate feedback primarily from peer teachers, as they seek to swap ideas and to experience practical alternatives from colleagues that share the same interests, concerns and the expertise of the classroom context. The abovementioned interactions supply opportunities for teachers' professional learning, as they develop processes which impact on their knowledge and their teaching practice, in terms of the IMPG. [For the complete volume, "Bridging Research and Practice in Science Education: Selected Papers from the ESERA 2017 Conference. Contributions from Science Education Research. Volume 6," see ED615249.]