Biological Response of Human Gingival Fibroblasts to Zinc-Doped Hydroxyapatite Designed for Dental Applications—An In Vitro Study

Abstract

This study aimed to investigate the biological response induced by hydroxyapatite (HAp) and zinc-doped HAp (ZnHAp) in human gingival fibroblasts and to explore their antimicrobial activity. The ZnHAp (with xZn = 0.00 and 0.07) powders, synthesized by the sol-gel method, retained the crystallographic structure of pure HA without any modification. Elemental mapping confirmed the uniform dispersion of zinc ions in the HAp lattice. The size of crystallites was 18.67 ± 2 nm for ZnHAp and 21.54 ± 1 nm for HAp. The average particle size was 19.38 ± 1 nm for ZnHAp and 22.47 ± 1 nm for HAp. Antimicrobial studies indicated an inhibition of bacterial adherence to the inert substrate. In vitro biocompatibility was tested on various doses of HAp and ZnHAp after 24 and 72 h of exposure and revealed that cell viability decreased after 72 h starting with a dose of 31.25 µg/mL. However, cells retained membrane integrity and no inflammatory response was induced. High doses (such as 125 µg/mL) affected cell adhesion and the architecture of F-actin filaments, while in the presence of lower doses (such as 15.625 µg/mL), no modifications were observed. Cell proliferation was inhibited after treatment with HAp and ZnHAp, except the dose of 15.625 µg/mL ZnHAp at 72 h of exposure, when a slight increase was observed, proving an improvement in ZnHAp activity due to Zn doping.

Salvia officinalis–Hydroxyapatite Nanocomposites with Antibacterial Properties

“…The preliminary findings gathered from the MTT cytotoxic assays were in good agreement with previous studies that reported data on the biological properties of hydroxyapatite and hydroxyapatite-based composites [39,[49][50][51][52]. In their previously reported studies on the "Biological response of human gingival fibroblasts to zinc-doped hydroxyapatite designed for dental applications-an in vitro study", Badea et al [53] highlighted that the decrease observed in cell viability was influenced by the concentration of the nanoparticles. Their findings suggested that the lowest number of cell viability was obtained after the cells were exposed to 500 µg/mL of ZnHAp and 62.5 µg/mL for HAp NPs.…”

“…Polymers 2023, 15, x FOR PEER REVIEW 14 of 18 designed for dental applications-an in vitro study", Badea et al [53] highlighted that the decrease observed in cell viability was influenced by the concentration of the nanoparticles. Their findings suggested that the lowest number of cell viability was obtained after the cells were exposed to 500 µg/mL of ZnHAp and 62.5 µg/mL for HAp NPs.…”

Biocompatibility and Osteogenic Activity of Samarium-Doped Hydroxyapatite—Biomimetic Nanoceramics for Bone Regeneration Applications

“…occupying lattice sites originally held by Ca 2+ ions, and anionic substitutions, occurring either at hydroxyl (e.g., F − and Cl − ) or phosphate (e.g., AsO 4 3− , SiO 4 4− , and CO 3 2− ) sites or at a combination of both. The presence of these dopants in the structure of nanoHAp results in modifications in the chemical, physical, biological, and mechanical properties [ 18 , 19 , 20 ].…”