Bone-repair properties of biodegradable hydroxyapatite nano-rods superstructures

NOELIA L. D'ELÍA; COLLEEN MATHIEU; CAROLINE D. HOEMANN; JUAN A. LAIUPPA; GRACIELA E. SANTILLAN; PAULA V. MESSINA

Nanoscale

ROYAL SOC CHEMISTRY

Año: 2015 vol. 7 p. 18751 - 18762

2040-3364

Nano-hydroxyapatite (nano-HAp) materials show an analogous chemical composition to the biogenic mineral component of calcified tissues and depending on their topography they may mimic the specific arrangement of the crystals in bone. In this work, we have evaluated the potential of four synthesized nano-HAp superstructures for the in vitro conditions bone-repair. Experiments are underway to investigate the effects of the material microstructure, surface roughness and hydrophilicity on their osseo-integration, osteo-conduction and osteo-induction abilities. Materials were tested in the presence of both, rat primary osteoblast and rabbit mesenchymal stem cell. The following aspects are discussed: (i) cytotoxicity and material degradation; (ii) rat osteoblast spreading, proliferation and differentiation; and (iii) rabbit mesenchymal stem cell adhesion on nano-HAp and nano-HAp/ collagen type I coatings. We effectively prepared a material based on biomimetic HAp nano-rods displaying the appropriate surface topography, hydrophilicity and degradation properties to induce the in vitro desired cellular responses for bone bonding and healing. Cells seeded on the selected material readily attached, proliferated and differentiate, as confirmed by cell viability, mitochondrial metabolic activity, alkaline phosphatase (ALP) activity and cytoskeletal integrity analysis by immunofluorescence localization of alpha-smooth muscle actin (alpha-SMA) protein. These results highlight the influence of material?s surface characteristics to determine their tissue regeneration potential and their future use in engineering osteogenic scaffolds for orthopedic implants.