Surgical treatment of serious pathologies such as breast cancer sometimes results in tissue loss, particularly after ablation (mastectomy), which is performed in almost 73% of cases. Europe is one of the regions of the world most affected by breast cancer and especially in the Franco-Belgian cross-border zone. The MATTISSE project proposes a new bioprosthesis that aims to help the body restore damaged areas following surgical procedures. Ultimately, patients who have benefited from this treatment have a natural prosthesis made up of their own fat cells, that is biodegradable and which does not require a second operation. To meet this challenge, MaT(T)ISSE is nurturing quality cross-border cooperation with complementary partners in their field of expertise: development of new absorbable and biocompatible biomaterials, transformation of these materials into customised wires, lace or 3D implantable objects. Their biological and medical interest is finally validated via implant protocols.