This study presents a layer by layer assembly on nanohydroxyapatite (nHA) particles with the dual aim of enhancing particle dispersion and biological response to produce superior reinforcements intended for load-bearing applications. The system tested consists of three sequential biological polyelectrolyte layers of heparin (representing glycosaminoglycans), polyhistidine (representing growth factors), and heparin adsorbed onto nHA. The results reveal that the resulting bio-nHA particles with an outer heparin layer are colloidally stable in aqueous solution for 23 days. Adsorption isotherms combined with Ca2+ release studies allowed a detailed description of each adsorbed layer. Release patterns for each adsorbed layer reveal that the biological polyelectrolytes are, at least in part, released as polyelectrolyte complexes. In conclusion, the combination of its colloidal dispersant properties and osteoinductive potential make the developed bio-nHA particles promising reinforcements to improve current composite biomaterials or bone-engineering scaffolds toward load-bearing dental and orthopedic applications.