Support for the initial attachment, growth and differentiation of MG-63 cells: a comparison between nano-size hydroxyapatite and micro-size hydroxyapatite in composites

Abstract

Hydroxyapatite (HA) is considered to be a bioactive material that favorably influences the adhesion, growth, and osteogenic differentiation of osteoblasts. To optimize the cell response on the hydroxyapatite composite, it is desirable to assess the optimum concentration and also the optimum particle size. The aim of our study was to prepare composite materials made of polydimethylsiloxane, polyamide, and nano-sized (N) or micro-sized (M) HA, with an HA content of 0%, 2%, 5%, 10%, 15%, 20%, 25% (v/v) (referred to as N0–N25 or M0–M25), and to evaluate them in vitro in cultures with human osteoblast-like MG-63 cells. For clinical applications, fast osseointegration of the implant into the bone is essential. We observed the greatest initial cell adhesion on composites M10 and N5. Nano-sized HA supported cell growth, especially during the first 3 days of culture. On composites with micro-size HA (2%–15%), MG-63 cells reached the highest densities on day 7. Samples M20 and M25, however, were toxic for MG-63 cells, although these composites supported the production of osteocalcin in these cells. On N2, a higher concentration of osteopontin was found in MG-63 cells. For biomedical applications, the concentration range of 5%–15% (v/v) nano-size or micro-size HA seems to be optimum.

Novel cellulose/hydroxyapatite scaffolds for bone tissue regeneration:In vitroandin vivostudy

“…Surfaces with nanostructures are found to preferably adsorb vitronectin—a glycoprotein involved in cell adhesion and spreading—due to its structural characteristics and chemical affinity (Lord, Foss, & Besenbacher, ). Supporting the enhanced adhesion process, cells adhered to surfaces loaded with nanostructured HA further expressed higher levels of beta‐actin and talin—proteins associated with focal adhesions and cytoskeletal activation, whose increased expression leads to a higher degree of cytoplasmic spreading (Filova et al, ), as presently verified for seeded cellulose/nHA scaffolds.…”

“…Regarding the latter, previous works have shown that, comparatively to μHA, nHA particles greatly enhance osteogenesis through the upregulation of distinct signalling pathways able to induce osteogenic commitment (Huang et al, ; Liu et al, ). This was further verified within cultures grown on composite structures loaded with either μHA or nHA particles (Filova et al, ; Li et al, ), with the latter exerting an osteogenic stimulation similar to the one attained with the addition of osteogenic growth factors to the culture environment (Polini, Pisignano, Parodi, Quarto, & Scaglione, ).…”

“…Additionally, a significantly higher MTT reduction value was verified for cultures grown on cellulose/nHA for 1 day, suggesting an increased number of active metabolic cells on the scaffold surface. Previous studies have shown that the addition of HA nanoparticles, in comparison with microparticles, enhances the osteoblastic cell adhesion within scaffolds of distinct compositions (Filova et al, ). The smaller size of nanoparticles and higher surface area promotes cell adhesion through increased and selective protein adsorption, leading to the formation of a neo‐matrix on the scaffold's surface, more suitable for cell interaction (Webster, Ergun, Doremus, Siegel, & Bizios, ).…”

Promoting Osseointegration of Ti Implants through Micro/Nanoscaled Hierarchical Ti Phosphate/Ti Oxide Hybrid Coating

“…55 The "grass-like" fibres could, to certain extent, promote the cell adherence. 56 Recent studies also confirmed that the hierarchical micro/nanoscale structure could activate the local immune response quickly, stimulate the cell transmembrane protein adhering and early adhesion of cells, 57,58 and promote deposition of HA and proliferation of osteoblasts. 59…”

Biological responses to nanomaterials: understanding nano-bio effects on cell behaviors

“…Because the biochemical and nanofeature cues obviously exhibited temporal-dependent dominance on cell behaviors, the combined effect of RGD peptide and HA nanoparticles within OPF hydrogel systems elicited a better biological response than that of the individual components. Filova et al (2014) prepared composite materials made of polydimethylsiloxane, polyamide, and nano-sized (100 ± 50 nm) or micro-sized (100 ± 50 lm) HA, with an HA content of 0%, 2%, 5%, 10%, 15%, 20%, and 25% (v/v) (referred to as N0-N25 or M0-M25). Nano-sized HA supported cell growth, especially during the first 3 d of culture.…”