scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Hydroxyapatite and Silicon-Modified Hydroxyapatite as Drug Carriers for 4-Aminopyridine

TL;DR: In this article, the authors investigated the suitability of nano-hydroxyapatite (HAP) and silicon-modified HAP (Si-HAP), for drug delivery.
Abstract: Adsorption and desorption properties of nano-hydroxyapatite (HAP) and silicon-modified hydroxyapatite (Si–HAP) were investigated with 4-aminopyridine (fampridine-4AP). The novelty of this research is the investigation of the suitability of the previously mentioned carriers for drug-delivery of 4AP. UV-VIS spectrophotometric results showed that the presence of silicon in the carrier did not significantly affect its adsorption capacity. The success of the adsorption was confirmed by thermal analysis (TG/DTA), scanning electron microscopy (SEM)/energy dispersive X-ray (EDX), Fourier transform infrared (FTIR) spectroscopy, and X-ray powder diffraction (XRPD). Drug release experiments, performed in simulated body fluid (SBF), revealed a drug release from Si–HAP that was five times slower than HAP, explained by the good chemical bonding between the silanol groups of the carrier and the 4AP functional groups. The electrochemical measurements showed a value of the polarization resistance of the charge transfer (Rct) more than five times smaller in the case of Si–HAP coating loaded with 4AP, so the charge transfer process was hindered. The electrochemical impedance results revealed that electron transfer was inhibited in the presence of 4AP, in concordance with the previously mentioned strong bonds. The silicon substitution in HAP leads to good chemical bonding with the drug and a slow release, respectively.
Citations
More filters
Journal ArticleDOI
TL;DR: A pH-sensitive multifunctional nanocomposite of doxorubicin and double hydroxidehydroxyapatite (DOX/[email protected]) was designed for drug targeted delivery and controlled release to enhance the cancer treatment efficacy as mentioned in this paper .

3 citations

Journal ArticleDOI
24 Aug 2022-Crystals
TL;DR: In this paper , the authors used a combination of cyclic voltammetry (CV) and differential pulse voltammetric (DPV) to detect toluidine blue (TB) electroanalysis in the phosphate buffer.
Abstract: Snail shells (Anadora Fulica) calcined at different temperatures were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, thermal analyses (TG-DTG), scanning electron microscopy (SEM) and N2 adsorption–desorption experiments (surface area measurements were found using the coupled BET/BJH method). The principal objective was to identify different forms of calcium carbonate and calcium hydroxide in snail shells as raw materials. The calcium hydroxide thus obtained was used in the synthesis of the hydroxyapatite/L-lysine (HA/Lys) composite. The composite used to chemically modify a glassy carbon electrode (GCE) was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). It appeared that the developed sensor Lys/HA/GCE facilitated electronic transfer compared to the pristine electrode. In a strongly acid medium, this surface protonated and therefore became positively charged, which allowed it to have a good affinity with [Fe(CN)6]3-. An application in toluidine blue (TB) electroanalysis in the phosphate buffer was carried out. Optimal sensor performances were obtained using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The performance of the sensor was determined in the concentration range 1 to 10 µM of TB, and the limit of detection (LOD) obtained by the S/N = 3 method was 2.78 × 10−7 M. The sensor was also used to detect the TB in spring water at 96.79% recovery.

2 citations

Journal ArticleDOI
TL;DR: In this article , the authors used the precipitation method to synthesize pure hydroxyapatite (HA), Si-and Mg-doped HA, which ensures the sustained release of doxycycline, and the investigation of the parameters which were crucial for the drug release.
Journal ArticleDOI
09 May 2023-Crystals
TL;DR: In this paper , a direct decomposition of calcium lactate pentahydrate chelates using dipotassium hydrogen phosphate under hydrothermal conditions was proposed for precise control of the HAp crystals morphology and product purity, which are necessary for biomedical applications.
Abstract: Hydroxyapatite (HAp) of different morphologies was prepared by the direct decomposition of calcium lactate pentahydrate chelates using dipotassium hydrogen phosphate under hydrothermal conditions. The proposed technique allows for precise control of the HAp crystals morphology and product purity, which are necessary for biomedical applications. The synthesis parameters such as reagent concentrations, pH, reaction time, temperature, pressure, and stirring rate were optimized in order to produce calcium phosphates (CaPs) ceramics with restricted morphologies and composition. As a result, we obtained hydroxyapatite in the form of whiskers, hexagonal rods, nano particles, flowers, and cylinders. The products were characterized according to their structure (FTIR and XRD), morphology (SEM), and functional properties, i.e., the specific surface area. The obtained results indicate that the reagent concentration and pH values have the greatest impact on the HAp properties; however, the proper combination of all the mentioned parameters should be considered when there is a need for a bioceramic with defined physicochemical properties and an appropriate morphology.
References
More filters
Journal ArticleDOI
TL;DR: In this paper, the passive oxide film formed on titanium and its natural growth in a phosphate buffered solution with and without an H2O2 addition have been investigated by electrochemical impedance spectroscopy (EIS) measurements over a period of several weeks.

545 citations

Journal ArticleDOI
TL;DR: In this literature review the biologically inspired scaffolds, bone substitutes, implants characterized by mechanical strength and biocompatibility, as well the drug delivery systems, based on hydroxyapatite are discussed.

429 citations

Journal ArticleDOI
TL;DR: The latest evolvement on (111)In-labeled nanoparticles for biodistribution assessment and/or imaging evaluation of nanocarriers, as well as therapy in cancer is overviewed.

189 citations

Journal ArticleDOI
TL;DR: The evidence on the applications of nanotechnology in designing drug delivery systems with the ability to cross through the blood-brain barrier (BBB) in order to transfer the therapeutic agents to the CNS is reviewed.

180 citations

Journal ArticleDOI
TL;DR: This paper concentrates on the degradation characteristics of hydroxyapatite (HA) coatings on orthopaedic Ti-6Al-4V alloy while immersed in Ringer's salt solution, which were investigated by electrochemical impedance spectroscopy.

164 citations