Search results for " Hydroxyapatite"

Morphostructural analysis of human follicular stem cells on highly porous bone hydroxyapatite scaffold

2007

In this study we investigated the in vitro behaviour, morphostructure and extracellular matrix synthesis of human dental follicular stem cells (hDFSCs) isolated from human dental bud, which resulted to be positive for mesenchymal markers (CD29, CD90, CD146 and CD166) by FACS analysis. Cells were analysed by light and electronic microscopy to evaluate their biological response either at week 1, that is before differentiation, or at weeks 3–6, when they had been cultured in osteogenic medium onto a highly porous natural scaffold material (Bio-Oss®). Microscopy analysis of primary culture cells showed they had a mesenchymal stem cell-like morphostructure, spindle shaped, similar to the cultur…

Biological characterization of Poly-L-lactic acid (PLLA)/Hydroxyapatite (HA)/Bioglass (BG) composite scaffolds made by Thermally Induced Phase Separa…

In the last few years, Tissue Engineering has focused on the favourable effects that composite scaffolds have on cell adhesion, growth and differentiation. In fact, composite scaffolds, usually composed of a synthetic polymer supplemented with naturally occurring components, display superior mechanical properties and bioconductivity than scaffolds consisting of a single component. Hydroxyapatite (HA) is the major inorganic component of bones. Bioglass (BG) is known to exert stimulatory effects on cells by ion release and hence, could be also advantageous for Bone Tissue Engineering. Poly-L-lactic acid (PLLA) is a versatile synthetic polymer combinable with HA and BG. The aim of this work wa…

Hydroxyapatite/Chitosan/Collagen coatings through galvanic coupling

In this work, the attention was focused on Hydroxyapatite/ Chitosan/Collagen composite as biocoatings for application in orthopaedic devices. Hydroxyapatite was selected for its osteoconductivity due to its chemical structure similar to bones. Collagen has the same function since 90-95% of bone matrix is constituted of collagen fibers. Furthermore, chitosan are largely used yet in medical field (e.g. antibacterial agent or drug deliver) and in this work were used to create a synergic interaction with hydroxyapatite and collagen to increase the strength and bioactivity of coating. Coatings were fabricated by galvanic deposition process that has different advantages an it does not require ext…

Comparison of adsorption equilibrium models and error functions for the study of sulfate removal by calcium hydroxyapatite microfibrillated cellulose…

2017

In the present study, the adsorption of sulfates of sodium sulfate (Na2SO4) and sodium lauryl sulfate (SLS) by calcium hydroxyapatite-modified microfibrillated cellulose was studied in the aqueous solution. The adsorbent was characterized using elemental analysis, Fourier transform infrared, scanning electron microscope and elemental analysis in order to gain the information on its structure and physico-chemical properties. The adsorption studies were conducted in batch mode. The effects of solution pH, contact time, the initial concentration of sulfate and the effect of competing anions were studied on the performance of synthesized adsorbent for sulfate removal. Adsorption kinetics indica…

Different Type Clay Amendments for Lead Immobilization in Contaminated Soils

2014

Contamination with lead in soil is a crucial problem in industrial and military sites. Immobilization of lead by natural and modified clay as soil amendment can be an effective solution to this problem. Quaternary and Devonian clays were chosen for modification with NaCl, CaCl2, FeOOH and Ca10(PO4)6(OH)2 in different proportions of Ca/P equimolar ratio to test and compare immobilization efficiency of lead (II) on raw and modified clays by using a batch leaching test. The aim of the study is to compare different types of raw and modified clays as soil amendments by lead immobilization properties.

A sustainable replacement for TiO2 in photocatalyst construction materials: Hydroxyapatite-based photocatalytic additives, made from the valorisation…

2018

The use of waste materials and by-products in building materials is of increasing importance to improve sustainability in construction, as is the incorporation of photocatalytic materials to both combat atmospheric pollution and protect the structures and façades. This work reports the innovative use of photocatalytic hydroxyapatite (HAp) based powders, derived from Atlantic codfish bone wastes, as an additive to natural hydraulic lime mortars. HAp is the main component of bone, and hence is non-toxic and biocompatible. This is the first time that such a calcium phosphate-based photocatalyst, or indeed any fish/marine derived wastes, have been added to building materials. A key factor is th…

Effect of addition of Nano hydroxyapatite particles on wear of resin modified glass ionomer by tooth brushing simulation

2016

Background Recently, incorporation of nanohydroxyapatite (NHA) has been suggested to improve the mechanical properties of glass ionomers (GIs). This study aimed to assess the effect of addition of NHA on wear of resin modified glass ionomer (RMGI) by tooth brushing simulation. Material and Methods In this in vitro, experimental study, NHA in 1, 2, 5, 7 and 10wt% concentrations was added to Fuji II LC RMGI powder, and 48 samples (5×5mm) in five experimental and one control group (n=8) were fabricated. After polishing, cleaning and incubation at 37°C for three weeks, the samples were weighed and subjected to tooth brushing simulation in a toothpaste slurry according to ISO14569-1. Then, they …

Home Oral Care Domiciliary Protocol for the Management of Dental Erosion in Rugby Players: A Randomized Clinical Trial

2022

People performing regular physical activity are at high risk of dental erosion especially in cases of high sport drinks intake. Biomimetic hydroxyapatite-based oral hygiene products, like toothpastes and mouthwashes, have been investigated in recent years for their remineralizing activity on the teeth. The aim of the present study was to evaluate the efficacy of two different oral hygiene protocols, respectively consisting of the combination of a hydroxyapatite-based toothpaste plus mouthwash (Trial group) or toothpaste alone (Control Group). At baseline (T0), as well as at 15 days (T1), 30 days (T2) and 90 days (T3), the following clinical indexes were assessed: Basic Erosive Wear Examinat…

Behavior of Calcium Phosphate–Chitosan–Collagen Composite Coating on AISI 304 for Orthopedic Applications

2022

Calcium phosphate/chitosan/collagen composite coating on AISI 304 stainless steel was investigated. Coatings were realized by galvanic coupling that occurs without an external power supply because it begins with the coupling between two metals with different standard electrochemical potentials. The process consists of the co-deposition of the three components with the calcium phosphate crystals incorporated into the polymeric composite of chitosan and collagen. Physical-chemical characterizations of the samples were executed to evaluate morphology and chemical composition. Morphological analyses have shown that the surface of the stainless steel is covered by the deposit, which has a very r…

Hydrothermally Synthesized Strontium Peroxyapatite

2015

The current research focuses on peroxide ion incorporation in the structure of strontium hydroxyapatite (SrHAp) by exposure to H2O2 ina closed hydrothermal vessel under mild conditions at 130 to 170 °C. Peroxide enriched strontium apatite (SrPerAp) was characterized for structure by X-Ray diffraction, for peroxide content- by permanganometric titration and then viewed by SEM. This study continued from previous work that used 30%H2O2 and showed a higher included peroxide content after processing with 50% H2O2 at 130 °C 70% of the theoretical peroxide content in apatitic channels of strontium apatite. This is the highest peroxide content incorporated to date and employs a lower temperature th…