I suggest you looking for the information in the scientific databases, such as Medline, Web of Science, Scopus, etc. Just type the keywords hydroxyapatite and PLLA or bioglass and PLLA in the publication titles and you will get hundreds of publications on the subject. Sort them by amount of citing and/or, among them, select the reviews and study them. As a starting point, you can look through a review of mine “Biocomposites and hybrid biomaterials based on calcium orthophosphates”:

https://www.researchgate.net/publication/236060167_Biocomposites_and_hybrid_biomaterials_based_on_calcium_orthophosphates

in which the subject of hydroxyapatite and PLLA is briefly mentioned and follow the references provided.

Article Biocomposites and hybrid biomaterials based on calcium orthophosphates

It depends on how you want to process the mixture further..one of the easiest way is to melt the polymer well below its degradation temperature, disperse HAP or bioglass  and allow stirring or any other dispersing technique.. other way is to dissolve the polymer in a suitable solvent and disperse the HAP or bioglass particles..

Hello all

thanks for your kindly answers

we want disperse HAP or bioglass in PLLA at melt state. did you know about it? what is the best condition in this way?

I would suggest dissolve the polymer in a solvent with the inorganic phase in a rotary evaporator. Use and excess of solvent to get a low viscosity. Then when it looks homogeneous, apply a vacuum to pull the solvent off and collect it. This way the polymer solution keeps moving and avoids sedimentation problems. You can get wide necked flasks to allow extraction of the finished material.

Polymer/bioactive glass nanocomposites for biomedical applications: A review

http://www.sciencedirect.com/science/article/pii/S0266353810002289

HYdroxyapatite/polymer