Calcium phosphates (CaPs) are widely accepted biomaterials able to promote the regeneration of bone tissue. However, the regeneration of critical-sized bone defects has been considered challenging, and the development of bioceramics exhibiting enhanced bioactivity, bioresorbability and mechanical performance is highly demanded. In this respect, the tuning of their chemical composition, crystal size and morphology have been the matter of intense research in the last decades, including the preparation of composites. The development of effective bioceramic composite scaffolds relies on effective manufacturing techniques able to control the final multi-scale porosity of the devices, relevant to ensure osteointegration and bio-competent mechanical performance. In this context, the present work provides an overview about the reported strategies to develop and optimize bioceramics, while also highlighting future perspectives in the development of bioactive ceramic composites for bone tissue regeneration.

Bone is a complex biologic tissue, which is extremely relevant for various physiological functions, in addition to movement, organ protection, and weight bearing. The repair of critical size bone defects is a still unmet clinical need, and over the past decades, material scientists have been expending efforts to find effective technological solutions, based on the use of scaffolds. In this context, biomimetics which is intended as the ability of a scaffold to reproduce compositional and structural features of the host tissues, is increasingly considered as a guide for this purpose. However, the achievement of implants that mimic the very complex bone composition, multi-scale structure, and mechanics is still an open challenge. Indeed, despite the fact that calcium phosphates are widely recognized as elective biomaterials to fabricate regenerative bone scaffolds, their processing into 3D devices with suitable cell-instructing features is still prevented by insurmountable drawbacks. With respect to biomaterials science, new approaches maybe conceived to gain ground and promise for a substantial leap forward in this field. The present review provides an overview of physicochemical and structural features of bone tissue that are responsible for its biologic behavior. Moreover, relevant and recent technological approaches, also inspired by natural processes and structures, are described, which can be considered as a leverage for future development of next generation bioactive medical devices.

Calcium-phosphate (CaP) scaffolds are widely regarded as the gold standard in orthopedics due to their biomimetic properties. However, next-generation bone substitutes should be multifunctional, promoting bone regeneration while simultaneously preventing post-surgical infections. This study investigates the interplay between physico-chemical properties, surface structure/-texture and hydrophilicity in modulating bacterial adhesion on two CaP-based scaffolds: a biomorphic non-sintered scaffold (GB) and a sintered MgSr-CaP ceramic scaffold. Surface morphology and topography were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM), while ionic release profiles were quantified by inductively coupled plasma optical emission spectroscopy (ICP-OES) and related to the surface activity. A computer-vision-based approach using Haralick texture descriptors was applied to quantitatively analyze surface features. Antibacterial performance was evaluated against Staphylococcus aureus (including MRSA), Escherichia coli, and Pseudomonas aeruginosa by quantifying colony-forming units (CFUs) after 6 h and by SEM and time-lapse confocal imaging. The GB scaffold significantly reduced bacterial adhesion compared with MgSr-CaP scaffold. Pearson correlation analysis further demonstrated that Haralick-derived texture features are strong predictors of bacterial attachment behavior. These findings highlight the potential of biomorphic fabrication strategies combined with advanced surface texture analysis to guide the design of next-generation infection-resistant orthopedic biomaterials.