**6. Conclusions**

Creating biomimetic implant materials is one of the challenges faced by modern chemistry and material engineering. Biologically inspired HA/Col composites seem very promising materials to replace autologous bone grafts. Analyzing their chemical, physicochemical, mechanical and biological properties, we observe that by modifying the methods of obtaining composites, and the composition of hydroxyapatite, the greatest similarity to physiological bone tissue is achieved. Among other composite materials used in orthopedic surgery, HA/Col composites are distinguished by good strength and flexibility, and above all else, high biocompatibility, bioactivity, osteoconductivity and bioresorbability. A review of previous studies, as well as visible new trends (3D printing, addition of medicinal substances) and a steady increase in interest in this topic, confirm that HA/Col composites have grea<sup>t</sup> potential in the treatment of bone defects and diseases.

**Author Contributions:** Surveyed the literature, prepared the original draft: B.K.; co-authored the review: A.K.; conceived the idea, managed the scope, organized the sections, co-authored and reviewed the manuscript: J.K. All authors discussed the results and commented on the manuscript. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Acknowledgments:** This work was supported by Medical University of Warsaw (FW23/N/2019).

**Conflicts of Interest:** The authors declare no conflict of interest.
