arXiv subjects

E. Salahinejad

Publications and source records attributed to E. Salahinejad.

13 recordsLinked to original sources

arXiv2026

Organosilane-functionalized hydrothermal-derived coatings on titanium alloys for hydrophobization and corrosion protection

This work focuses on the structure, wettability and corrosion behaviors of Ti-6Al-4V alloy after roughening treatments in different concentrations of NaOH aqueous solutions followed by low surface energy hexadecyltrimethoxysilane (HDTMS) coating. In this regard, scanning electron microscopy, contact angle measurements, potentiodynamic polarization and electrochemical impedance spectroscopy were used to characterize the samples. In contrast to hydrophilicity caused by the hydrothermal alkaline treatments, the subsequent HDTMS coating donated considerable hydrophobicity. Typically, the highest sessile water contact angle (about 147 deg) was obtained for the sample treated in 3 molar NaOH solution followed by the HDTMS coating. In addition, the alkaline treatment reduced the corrosion resistance of the surface in a NaCl aqueous solution; however, the HDTMS hydrophobization process improved it significantly. It is eventually concluded that the coupled use of alkaline treatment and HDTMS functionalization can be further considered for moisture-exposed applications of Ti-based alloys.

cond-mat.mtrl-sci↗

arXiv2026

Competition of carrier bioresorption and drug release kinetics of vancomycin-loaded silicate macroporous microspheres to determine cell biocompatibility

Bioceramic porous microspheres are promising substances for dental and orthopedic bone void filling, tissue engineering and drug delivery applications. In this research, the structure and cytocompatibility of bioactive magnesium-calcium silicate macroporous microspheres loaded with vancomycin hydrochloride, an antibiotic drug, were studied. In this regard, bredigite (Ca7MgSi4O16), akermanite (Ca2MgSi2O7) and diopside (CaMgSi2O6) carriers were fabricated through a sequence of sol-gel, calcination, droplet extrusion and sintering processes, followed by impregnated with vancomycin. X-ray diffraction (XRD) and scanning electron microscopy verified the formation of the desired ceramic crystalline phases and macroporous characteristics of the carriers, respectively. Based on the MTT assay, the antibiotic-loaded bredigite, akermanite and diopside devices comparatively exhibited the lowest, intermediate and highest levels of human bone marrow mesenchymal stem cells (hBM-MSCs) viability and proliferation, respectively. It was concluded that the role of the carrier bioresorption kinetics prevails over the drug delivery kinetics in determining the cell biocompatibility of the devices.

physics.bio-ph↗

arXiv2026

Drug-delivery Ca-Mg silicate scaffolds encapsulated in PLGA

The aim of this work is to develop dual-functional scaffolds for bone tissue regeneration and local antibiotic delivery applications. In this respect, bioresorbable bredigite (Ca7MgSi4O16) porous scaffolds were fabricated by a foam replica method, loaded with vancomycin hydrochloride and encapsulated in poly lactic-co-glycolic acid (PLGA) coatings. Field emission scanning electron microscopy, Archimedes porosimetry and Fourier-transform infrared spectroscopy were used to characterize the structure of the scaffolds. The drug delivery kinetics and cytocompatibility of the prepared scaffolds were also studied in vitro. The bare sample exhibited a burst release of vancomycin and low biocompatibility with respect to dental pulp stem cells based on the MTT assay due to the fast bioresorption of bredigite. While keeping the desirable characteristics of pores for tissue engineering, the biodegradable PLGA coatings modified the drug release kinetics, buffered physiological pH and hence improved the cell viability of the vancomycin-loaded scaffolds considerably.

physics.bio-ph↗

arXiv2026

Controlled release from polyurethane films: drug release mechanisms

In this study, polyurethane-films loaded diclofenac were used to analyze the drug release kinetics and mechanisms. For this purpose, the experimental procedures were developed under static and dynamic conditions with different initial drug loads of 10, 20, and 30%. In the dynamic condition, to better simulate the biological flow, drug release measurements were investigated at flow rates of 7.5 and 23.5 ml/s. These values indicate the flow rate of the internal carotid artery (ICA) for a normal state of a body and for a person during the exercise, respectively. The experimental data were analyzed and adjusted by Higuchi, Korsmeyer-Peppas, First-order, zero-order, and Peppas-Sahlin models in order to understand the mechanisms contributed. Finally, Drug release mechanisms were specified by investigating the model correlation coefficients. Experimental results showed that increasing the flow rate and initial drug loads enhance drug liberation. In addition, the rate of release is more influenced by the drug dosage in the static state. The analysis revealed that diffusion, burst, and osmotic pressure are the principal mechanisms contributed. Moreover, Fickian type was the dominant mechanism at all duration of release. However, it was discovered using Peppas-Sahlin model that the contribution of the diffusion mechanism decreases with increasing flow rate and initial dosage. Furthermore, the tests at different drug dosages showed that the number of stages in medication release profile is independent of the flow rate and the medicine percentage. One can conclude that the drug release kinetic in static state is more influenced by drug dosage compare to dynamic state.

physics.med-ph↗

arXiv2026

Effects of PLGA coating on biological and mechanical behaviors of tissue engineering scaffolds

Scaffolds have a key role in the clinical success of tissue engineering for the regeneration of damaged tissues. Their bio-performance is often described as the extent to which they can provide an extracellular matrix-like environment for cells embedded where their function and growth can effectively continue. For this purpose, tissue engineering scaffolds should exhibit biodegradability, biocompatibility, bioactivity, delivery, and mechanical performance. The use of polymer coatings, especially poly(lactic-co-glycolic acid) (PLGA), on tissue engineering scaffolds has been found to be one of the most effective methods to improve the scaffold properties. This paper reviews the techniques used to coat tissue engineering scaffolds with PLGA and its effects on the mechanical characteristics, biodegradability, biocompatibility, Molecular delivery, and osteointegration of the scaffolds. It is concluded that apart from apatite-formation ability, all bio-functionalities can be tuned through PLGA coatings. This reflects the great potential of this modification approach to be used in tissue regeneration and therapeutic delivery applications.

physics.bio-ph↗

arXiv2026

Controlled drug delivery from chitosan-coated heparin-loaded nanopores anodically grown on nitinol shape-memory alloy

Nitinol (NiTi shape-memory alloy) is an interesting candidate in various medical applications like dental, orthopedic, and cardiovascular devices, owing to its unique mechanical behaviors and proper biocompatibility. The aim of this work is the local controlled delivery of a cardiovascular drug, heparin, loaded onto nitinol treated by electrochemical anodizing and chitosan coating. In this regard, the structure, wettability, drug release kinetics, and cell cytocompatibility of the specimens were analyzed in vitro. The two-stage anodizing process successfully developed a regular nanoporous layer of Ni-Ti-O on nitinol, which considerably decreased the sessile water contact angle and induced hydrophilicity. The application of the chitosan coatings controlled the release of heparin mainly by a diffusional mechanism, where the drug release mechanisms were evaluated by the Higuchi, first-order, zero-order, and Korsmeyer-Pepass models. Human umbilical cord endothelial cells (HUVECs) viability assay also showed the non-cytotoxicity of the samples, so that the best performance was found for the chitosan-coated samples. It is concluded that the designed drug delivery systems are promising for cardiovascular, particularly stent applications.

physics.bio-ph↗

arXiv2025

Fluoride doping into SiO2-MgO-CaO bioactive glass nanoparticles: bioactivity, biodegradation and biocompatibility assessments

In this research, for the first time, the structure, bioactivity, biodegradation and biocompatibility of SiO2-MgO-CaO glasses doped with different levels of fluoride were studied. The glassy powder samples were synthesized by a coprecipitation method followed by calcination at 500 C, where amorphicity and fluoride incorporation were verified by X-ray diffraction and Raman spectroscopy, respectively. The in vitro biomineralization and biodegradation of the samples were also investigated by electron microscopy, Raman spectroscopy and inductively coupled plasma optical emission spectrometry. These assessments revealed that there is an optimum level of fluoride doping to meet the highest bioactivity. Remarkably, the same level of incorporation presented the foremost biocompatibility with respect to osteoblast-like MG-63 human cells, as realized by the MTT assay and cell attachment studies.

cond-mat.mtrl-sci↗

arXiv2025

Structure, biomineralization and biodegradation of Ca-Mg oxyfluorosilicates synthesized by inorganic salt coprecipitation

In this research, a novel group of Ca-Mg oxyfluorosilicates containing different levels of fluoride substituting for oxide was synthesized by an inorganic salt coprecipitation process followed by calcination/sintering. The effects of the incorporation of fluoride on the resultant structural characteristics, apatite-forming ability and biodegradability were evaluated by X-ray diffraction, transmission electron microscopy, scanning electron microscopy/energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, inductively coupled plasma spectroscopy and pH measurements. According to the results, the samples containing up to 2 mol% F present a single-phase structure of diopside (MgCaSi2O6) doped with F. It was also found that to meet the most biomineralization characteristic, the optimal value of fluoride in the homogeneous samples is 1 mol%. In this regard, on the one hand, the partial incorporation of fluoride into apatite (via forming fluorohydroxyapatite) and, on the other hand, the absence of fluorite (CaF2) as a consumer of Ca in the deposits are responsible for achieving the most apatite-forming ability circumstance controlled by an ion-exchange reaction mechanism. In conclusion, this study reflects the merit of the optimization of fluoride-doping into Ca-Mg silicates for development in biomedicine.

cond-mat.mtrl-sci↗

arXiv2025

Toward reducing the formation temperature of diopside via wet-chemical synthesis routes using chloride precursors

Reducing the formation temperature of single-phase multioxides is one of the classic challenges in ceramic processing, including wet-chemical synthesis routes. Toward pursuing this aim for diopside (MgCaSi2O6), the merit of different sol-gel and coprecipitation processes using the related chloride precursors followed by calcination was compared from the viewpoints of crystallinity and homogeneity. In accordance to the results, the use of the sol-gel techniques, directed with/without an alkaline catalyst, gave rise to the unfavorable creation of multiphase and low-crystallinity structures. Regarding the coprecipitation methods, the one-step addition of a precipitant agent is accompanied by an indirect low-temperature formation of nano-diopside, while a direct crystallization into this phase was explored in the dropwise condition, albeit with a lower crystallinity. Thus, by employing a suitable synthesis processing, it is feasible to take control of a wide range of nanoparticulate diopside-based structures achieved after a low-temperature calcination.

cond-mat.mtrl-sci↗

arXiv2025

Eliminating the irregular surface layer of anodically-grown Ni-Ti-O nanopore arrays in a two-stage anodization

Nanopores (NPs) grown by anodizing can be partially hidden beneath a relatively compact surface oxide layer, which limits the volumetric surface area of these nanostructures. In this work, nitinol (NiTi) alloy was anodized in an electrolyte containing ethylene glycol, water, and sodium chloride in static and stirred electrolyte stages with the aim of removing the irregular surface array while achieving a thick NP layer. Electron micrographs showed that anodization in the static electrolyte provides a controlled thickness of NP layers covered by an irregular surface layer. In contrast, anodizing in the stirred electrolyte reduced the thickness and the degree of irregularity, which were controlled by the different kinetics of dissolution at the tops, perimeters and bottoms of NPs. To benefit simultaneously from the thickness and regularity of the oxide layers, two-stage anodizing under static and then stirred electrolyte conditions was found to be effective. Following a 30 min anodization in the static electrolyte, anodizing for 30 min under the stirred conditions provided the highest regularity in the oxide array, resulting in NPs of almost 40 nm and 11 μm in diameter and layer thickness, respectively. Two-stage anodizing under static then stirred electrolyte conditions is proposed in order to promote NP structures for applications demanding higher surface areas.

cond-mat.mtrl-sci↗

arXiv2025

Microscopic and spectroscopic evidences for multiple ion-exchange reactions controlling biomineralization of CaO.MgO.2SiO2 nanoceramics

This study is focused on the mechanism of in vitro biomineralization on the surface of CaO.MgO.2SiO2 (diopside) nanostructured coatings by scanning electron microscopy, energy-dispersive X-ray spectroscopy and inductively coupled plasma spectroscopy assessments. A homogeneous diopside coating of almost 2 um in thickness was deposited on a medical-grade stainless steel by coprecipitation, dipping and sintering sequences. After soaking the sample in a simulated body fluid (SBF) for 14 days, a layer with the thickness of 8 μm is recognized to be substituted for the primary diopside deposit, suggesting the mineralization of apatite on the surface. Investigations revealed that the newly-formed layer is predominantly composed of Ca, P and Si, albeit with a biased accumulations of P and Si towards the surface and substrate, respectively. The variations in the ionic composition and pH of the SBF due to the incubation of the sample were also correlated with the above-interpreted biomineralization. In conclusion, the multiple ion-exchange reactions related to Ca, Mg, Si and P were found to be responsible for the in vitro bioactivity of nanodiopside.

cond-mat.mtrl-sci↗

arXiv2025

Fabrication, drug delivery kinetics and cell viability assay of PLGA-coated vancomycin-loaded silicate porous microspheres

Porous ceramic microspheres are a desirable substance for bone tissue reconstruction and delivery applications. This study focuses on Mg-Ca silicate microspheres encapsulated in biodegradable poly (lactic-co-glycolic acid) (PLGA) to serve as a biocompatible carrier for the controlled release of vancomycin hydrochloride. In this regard, diopside (MgCaSi2O6), bredigite (MgCa7Si4O16) and akermanite (MgCa2Si2O7) powders were synthesized by sol-gel and subsequent calcination methods. Then, porous akermanite, diopside and bredigite microspheres of 700-1000 um in diameter were fabricated by using carbon porogen, droplet extrusion and sintering, then loaded with the drug and eventually coated with PLGA. The bare microspheres showed a considerable burst release mode of the drug into a physiological medium, whereas PLGA coating of the microspheres reduced the burst release level. To investigate effective mechanisms governing in the drug release from the carriers, the contribution of burst, degradation, and diffusion was analyzed by the sequential quadratic programming algorithm method. It was found that the relative contribution of diffusion to bioresorption is ranked as diopside > akermanite > bredigite, whereas PLGA coating dominates the diffusion mechanism. The dental pulp stem cells cytocompatibility MTT assay of the microspheres also showed that the drug loading deteriorates but PLGA coating improves the cell biocompatibility significantly. Comparatively, the biocompatibility of the PLGA-coated microspheres was ranked as akermanite > diopside > bredigite, as a result of a compromise between the release of the constituting ions of the ceramic carriers and vancomycin molecules. It was eventually concluded that PLGA-coated Mg-Ca silicate microspheres are promising candidates for drug-delivery bone tissue engineering and dental bone grafting applications.

physics.med-ph↗

arXiv2025

Enhanced sinterability and in vitro bioactivity of diopside through fluoride doping

In this work, diopside (CaMgSi2O6) was doped with fluoride at a level of 1 mol.%, without the formation of any second phase, by a wet chemical precipitation method. The sintered structure of the synthesized nanopowders was studied by X-ray diffraction, Fourier transform infrared spectroscopy and field-emission scanning electron microscopy. Also, the samples' in vitro apatite-forming ability in a simulated body fluid was comparatively evaluated by electron microscopy, inductively coupled plasma spectroscopy and Fourier transform infrared spectroscopy. According to the results, the material's sinterability was improved by fluoride doping, as realized from the further development of sintering necks. It was also found that compared to the undoped bioceramic, a higher amount of apatite was deposited on the surface of the doped sample. It is concluded that fluoride can be considered as a doping agent in magnesium-containing silicates to improve biological, particularly bioactivity, behaviors.

cond-mat.mtrl-sci↗