The authors determined conditions for manufacturing PAN precursor fibers containing a system of two nanoadditives, montmorillonite (MMT), and hydroxyapatite (HAp) in their structure. The PAN precursor fibers thus obtained are characterized by a tenacity of more than 30 cN/tex and a total volume of pores a the level of 0.29 cm(3)/g. Furthermore, it vas found that the Use of nanoadditives entails the remodeling of the para-crystalline structure of PAN fibers into a strictly crystalline one. This is accompanied by a decrease in between MMT layers combined with their partial exfoliation. The fibers thus obtained, after being carbonized, will be used for medical applications. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 2343-2350, 2009