Surface cationic functionalized nano-hydroxyapatite – Preparation, characterization, effect of coverage on properties and related applications.

• Functionalized nHAp was obtained using arginine or polyethylenimine. • Resulted nanoparticles were comparatively characterized relative to used modifiers. • Linear polyethylenimine coated hydroxyapatite had the best DNA binding ability. • Use of LPEI functionalized nHAp in biocomposites recipe had a strengthening effect. • The 3D constructs demonstrated rapid self–recovery and fatigue resistant behavior. Functionalized nano-hydroxyapatite (nHAp) was obtained by wet chemical technique, using arginine (Arg) or polyethylenimine (branched-bPEI, or linear-LPEI) as cationic modifiers and dispersing agents. TEM, FT-IR, SEM, DLS and WAXD characterization results showed that the prepared nanoparticles possessed needle- or plate-like morphologies and Arg and PEI were successfully grafted onto nHAp. LPEI functionalized nHAp exhibited a good similitude with biological apatite and the best DNA binding ability. In addition, the incorporation of nHAp/LPEI nanoparticles within collagen/dimethylsilanediol hyaluronate-based porous matrices pointed out a significant improvement of the compressive modulus of biocomposites: up to a six-fold increase, compared with the polymer matrix without fillers. Moreover, the composite sponges revealed high toughness during five consecutive compression tests without any permanent deformation and cracks. Therefore, nHAp/LPEI nanoparticles could be considered promising materials for biomedical applications, like gene carrier or reinforcement filler with strong interfacial adhesion in biocomposites for bone engineering. [ABSTRACT FROM AUTHOR]