Pure hydroxyapatite can be used as a bone substitute material, but it has some limitations. Pure hydroxyapatite has relatively low mechanical strength and is not as biocompatible as natural bone. In addition, pure hydroxyapatite is brittle and prone to cracking, which can reduce its effectiveness as a bone substitute.

To overcome these limitations, hydroxyapatite is often used in combination with other materials to form composite bone substitute materials. These materials are designed to have improved mechanical properties and better biocompatibility compared to pure hydroxyapatite.

Some common additives used in hydroxyapatite-based composite bone substitute materials include:

Overall, hydroxyapatite can be used alone or in combination with other materials to form bone substitute materials. Composite materials that include hydroxyapatite often have improved mechanical properties and biocompatibility compared to pure hydroxyapatite.

pure hydroxyapatite couldn't be used as bone substitutes due to its low mechanical properties.

I agree with both opinions.

Hi,

if you mention about using Hydroxyapatite (Hap) without any growth factors by saying pure hydroxyapatite, yes it can be used. It is obviously very similar to inorganic part of the bone so why not. You can easily check the literature about this.

For example interconnected porous hydroxyapatite is used as a bone graft substitute in clinics in past (Yoshikawa H, J. R. Soc. Interface. 6S341–S348) . There still are some commercial hydroxyapatite products. It just depends on your aim and the bone/place you apply it. You can increase and decrease the strength/mechanical properties by changing the porosity or the size of the hydroxyapatite (ex. nanohydroxyapatite). Yet it is reported to be osteoconductive but not osteoindictuve so you may need some growth factors or cytokines to promote osteoinduction though.

Please check this review article for more detail

Article Bone regeneration with hydroxyapatite-based biomaterials

Good luck with the work.

ZB

hydroxyapatite has relatively low mechanical strength