Osteoporosis is a worldwide disease resulting in the increase of bone fragility and enhanced fracture risk in adults. In the context of osteoporotic fractures, bone tissue engineering (BTE), i.e., the use of bone substitutes combining biomaterials, cells, and bone inducers, is a potential alternative to conventional treatments. Pre-clinical testing of innovative scaffolds relies on in vitro systems where the simultaneous presence of osteoblasts (OBs) and osteoclasts (OCs) is required to mimic their crosstalk and molecular cooperation for bone remodelling. To this aim, two composite materials based on type I collagen were developed, containing either strontium-enriched mesoporous bioactive glasses or rod-like hydroxyapatite nanoparticles. Following chemical crosslinking with genipin, the nanostructured materials were tested for 2–3 weeks with an indirect co-culture of human trabecular bone-derived OBs and buffy coat-derived OC precursors. The favourable structural and biological properties of the materials proved to successfully support the viability, adhesion, and differentiation of bone cells, encouraging a further investigation of the two bioactive systems as biomaterial inks for the 3D printing of more complex scaffolds for BTE.