@article {19926,
	title = {Mineralization of layer-by-layer ultrathin films containing microfluidic-produced hydroxyapatite nanorods},
	journal = {Crystal Growth \& Design},
	volume = {19},
	year = {2019},
	month = {2019-09-25 00:00:00},
	pages = {6351 - 6359},
	publisher = {ACS},
	abstract = {
We describe the assembly of layer-by-layer (LbL) ultrathin films containing bioactive hydroxyapatite (HAp) rod-shaped nanoparticles with mineralizing capacity. Monodisperse 96 nm long and 9 nm wide HAp nanorods with a surface charge of {\textendash}14 mV were produced with a microfluidic system. The negatively charged HAp nanorods were assembled with the polycation poly-L-lysine (PLL) in LbL fashion. The successful deposition of alternating layers was confirmed by quartz-crystal microbalance with dissipation monitoring. The Voigt-based viscoelastic model demonstrated steady film growth where three PLL/HAp bilayers reached a thickness of 70 nm. The bioactivity of [PLL/HAp]3 was evaluated in vitro by following the formation of a mineralized hydroxyapatite layer in simulated body fluid (SBF). X-ray diffraction, energy-dispersive X-ray spectroscopy and scanning electron microscopy (SEM) demonstrated formation of a crystalline hydroxyapatite layer and complete surface coverage within 7 days. SaOs-2 osteoblasts-like cells attached to the mineralized surfaces and developed longer filopodia extensions when compared to non-mineralized samples. Our results showed that [PLL/HAp]3 films are feasible osteoconductive coatings applicable to orthopedic implants and fixation devices.
},
	keywords = {electrostatic interactions, hydroxyapatite, layer-by-layer, Microfluidics, osteoconductivity},
	issn = {1528-7483},
	doi = {10.1021/acs.cgd.9b00831},
	url = {https://pubs.acs.org/doi/10.1021/acs.cgd.9b00831},
	author = {Rial, R. and Costa, R. R. and Reis, R. L. and Liu, Z. and Pashkuleva, I. and Ruso, J. M.}
}