Mohammad Khodaei

Golpayegan University of Engineering · Department of Material Science and Engineering

This study focused on a modified Fused Deposition Modeling (FDM) 3D printing method, specifically the direct pellet printing of a propylene-based thermoplastic elastomer, Vistamaxx™ 6202, to address challenges like printability and weak mechanical properties. The main objective was optimizing printing parameters and investigating their impact on th...

The mechanical properties of 3D-printed scaffolds for load-bearing implantation are crucial. Although the addition of nanoparticles to polymeric scaffolds can improve their mechanical and biological properties, due to certain limitations in printability, high amounts of reinforcement cannot be used. Therefore, in this study, an attempt was made to...

Background This study aimed to evaluate the effect of new computer-aided design/computer-aided manufacturing all-ceramic materials on the viability and adhesion properties of human gingival fibroblasts (HGFs). Materials and Methods In this experimental study, the proliferation and adhesion potential of the cells were evaluated by seeding the HGF c...

Because of their desirable characteristics, ceramic-based scaffolds have emerged as prominent candidates for artificial bone replacements in bone regeneration procedures. Bredigite (Ca7MgSi4O16) ceramic has demonstrated favorable bioactivity, bone growth, and mechanical qualities, making it a viable candidate for replacing bone defects. This review...

This study introduces novel PETG–ABS–Fe3O4 nanocomposites that offer impressive 3D- and 4D-printing capabilities. These nanocomposites can be remotely stimulated through the application of a temperature-induced magnetic field. A direct granule-based FDM printer equipped with a pneumatic system to control the output melt flow is utilized to print th...

Stretchable elastomers play a crucial role in various applications such as soft robotics and flexible electronics. Traditional manufacturing methods for stretchable elastomers face limitations in terms of material waste and production time. This paper presents a direct pellet printing technique using pneumatic pressure to fabricate a highly stretch...

In this study, Acrylonitrile butadiene styrene (ABS) with three different ratios of 30%, 50%, and 70% is used to enhance the shape memory and mechanical properties of Polyethylene terephthalate glycol (PETG). Additionally, morphology, printability, and dynamic thermomechanical analysis are also examined. The thermal test results show that PETG‐ABS...

A significant obstacle in bone tissue engineering is the creation of biodegradable bone replacements with the requisite mechanical and biological capabilities to treat more severe and intricately shaped injuries. Baghdadite has recently indicated that active biological ions such as silicon (Si⁴⁺) and zirconium (Zr⁴⁺) have been proven to increase bo...

In this work, baghdadite (Bag) bioceramic powder was synthesized using the mechanical activation method and was characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques, whereas, its phase purity was confirmed. Then, polycaprolactone (PCL) porous scaffolds including different amounts of Bag (0, 15, and 30 wt%) w...

The medical field, particularly dentistry, frequently employs cobalt-chromium-molybdenum dental alloys for their biocompatibility, strength, corrosion resistance, and wear resistance. This study aimed to assess the impact of the cooling rate during alloy casting on the structural properties, corrosion resistance, and mechanical properties. Three sa...

Engineered cardiac constructs (ECC) aid in the progression of regenerative medicine, disease modeling and targeted drug delivery to adjust and aim the release of remedial combination as well as decrease the side effects of drugs. In this research, polycaprolactone/gold nanoparticles (PCL/GNPs) three-dimensional (3D) composite scaffolds were manufac...

Wound care and treatment can be critical from a clinical standpoint. While different strategies for the management and treatment of skin wounds have been developed, the limitations inherent in the current approaches necessitate the development of more effective alternative strategies. Advances in tissue engineering have resulted in the development...

This study investigated the relationship between the structure and mechanical properties of polycaprolactone (PCL) nanocomposites reinforced with baghdadite, a newly introduced bioactive agent. The baghdadite nanoparticles were synthesised using the sol–gel method and incorporated into PCL films using the solvent casting technique. The results show...

A significant obstacle in bone tissue engineering is the creation of biodegradable bone replacements with the requisite mechanical and biological capabilities to treat more severe and intricately shaped injuries. Baghdadite has recently indicated that active biological ions such as silicon (Si ⁴⁺ ) and zirconium (Zr ⁴⁺ ) have been proven to increas...

Bioactive ceramics paly vital role in tissue engineering. One of the most important silicate base bioceramics is akermanite. In this research, the akermanite powder, was synthetized using sol-gel method and the effect of different substituents of Cobalt, Copper, Strontium and Zinc on its properties investigated. Results of Field Emission Scanning E...

Gelatin crosslinking using conventional methods is usually associated with some toxic side effects. In this research, therefore, the vacuum heating method at 10 Pascal and 140°C under different times of 8, 16, and 32 h was used to cross-link strontium-loaded gelatin microparticles with varying degrees obtained by the oil/water mixing method on tita...

Skin is the first line of defense against pathogenic microorganisms. Any serious damage to this organ can lead to bacterial invasion and wound infection. Such infections can cause not only a delay in the healing process, but also more serious complications such as tissue necrosis or even sepsis, which can lead to life-threatening conditions. Theref...

Background: The digital dentistry, requires materials with wo opposite properties of machining ability and also enough hardness. The main objective of this experimental study was to investigate the fabrication feasibility of the lithium metasilicate glass-ceramic in partially crystalized stated using the spark plasma sintering (SPS) method. Mater...

Introduction: The use of porous nanobiocomposite scaffolds for maxillofacial fractures and internal surface optimization of artificial grafts utilizing nanotechnology can improve cell adhesion, mechanical properties, and adsorption rate. Porous scaffolds have been the subject of numerous investigations, especially for broken and damaged parts of th...

The aim of the study was to investigate the effect of different surface treatment of titanium (Ti) on the adhesion test results for dental application. Ti substrates roughened by 400 to 1 500-grit SiC polish papers and alumina blasting, alkali treated by 5 molar (M) NaOH and KOH solutions and heat treated at the temperature range of 400–800 °C were...

Initial lithium silicate glass frits with different SiO2/Li2O ratio were prepared by the melting method. In this study, the obtained glass frits were hot-pressed at different temperatures of 550, 650 and 750°C; however, only samples sintered at 750°C were sintered and densified. The properties of the obtained lithium metasilicate glass ceramics (LM...

One of the challenges in critical size bone defect repairing is the use of a porous degradable scaffold with appropriate properties to the host tissue. Nowadays, the three-dimensional (3D) printing method can produce custom and personalized scaffolds and overcome the problems of traditional methods by controlling the porosity and dimensions of biom...

Bone tissue engineering is a field to manufacture scaffolds for bone defects that cannot repair without medical interventions. Ceramic nanoparticles such as bredigite have importance roles in bone regeneration. We synthesized a novel strontium (Sr) doped bredigite (Bre) nanoparticles (BreSr) and then developed new nanocomposite scaffolds using poly...

The human's heart cannot regenerate after a wound by itself. So myocardial tissue can be damaged, leading to acute inflammation and scar. To overcome this issue, three dimensional (3D) scaffolds with appropriate properties have been proposed. In this study, Poly ε-caprolactone (PCL)/Gold nanoparticles (GNPs) nanocomposite scaffolds containing 0, 0....

The clinical performance of dental composite restoration and its overall success are the result of physical, mechanical, and biological properties of the filling materials. The present study aimed to evaluate surface roughness, flexural properties, and cytotoxicity of two nanohybrids, namely, MI Gracefil and Herculite Ultra, and one nanoceramic den...

Background and aims: The presence of an appropriate scaffold at the wound site could significantly improve the healing process. In this study, we aimed to prepare a biomimetic nanocomposite scaffold composed of chitosan, gelatin, and 58S bioglass nanoparticles for skin tissue engineering. Methods: The nanocomposite scaffolds composed of chitosan, g...

In this study different heat treatment temperatures have been applied for titanium implant after surface modification through chemical treatment by Hydrogen Peroxide (H2O2). X-ray diffraction (XRD) analysis revealed that the main phase at the surface of heat-treated sample at temperatures below than 650 °C is Anatase, moreover, the presence of Anat...

Chronic wounds are among the most therapeutically challenging conditions, which are commonly followed by bacterial infection. The ideal approach to treat such injuries are synergistic infection therapy and skin tissue regeneration. In the recent decades, nanotechnology has played a critical role in eradicating bacterial infections by introducing se...

In this study, nano-biocomposites of polycaprolactone (PCL) as the matrix and different amounts of nanofluorapatite (nFA) (0, 10, 20 and 30 wt.%) as the reinforcement were prepared for possible scaffold fabrication using the fused filament fabrication (FFF) 3D printer. Field Emission Scanning Electron Microscopy (FE-SEM) and Energy Dispersive Spect...

Today, chronic wound care and management can be regarded as a clinically critical issue. However, the limitations of current approaches for wound healing have encouraged researchers and physicians to develop more efficient alternative approaches. Advances in tissue engineering and regenerative medicine have resulted in the development of promising...

Introduction: Zirconium oxide or zirconia have been used for the fabrication of dental implants due to their biocompatibility, hardness, toughness, compressive strength and chemical stability. The aim of this study is investigating the effect of sintering time on the properties of zirconia dental implant. Materials and Methods: In this research, wh...

Yttria doped ZrO2 was deposited using an acidic zinc phosphatizing solution and the hydrothermal treatment. The coating was analyzed using a field emission-scanning electron microscope (FE-SEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). A piston on three balls (ISO 6872) was used...

Objective To evaluate the effects of remineralizing agents on the shear bond strength (SBS) of orthodontic brackets bonded to intact and demineralized enamel. Material and Methods In this in-vitro study, 160 human premolars were divided into 8 groups, including group 1 with intact enamel as the positive control, group 2 with demineralized enamel a...

Any significant loss of vision or blindness caused by corneal damages is referred to as corneal blindness. Corneal blindness is the fourth most common cause of blindness worldwide, representing more than 5% of the total blind population. Currently, corneal transplantation is used to treat many corneal diseases. In some cases, implantation of artifi...

A degradable drug delivery system with a slow local release rate can be a promising method to modify tissue engineering scaffolds for bone remodeling. In this study poly lactic acid/akermanite composite scaffolds with different concentrations of akermanite were fabricated through fused deposition modeling (FDM) and coated with some gentamicin-loade...

The cover image is based on the Research Article Evaluating the effects of vacuum on the microstructure and biocompatibility of bovine decellularized pericardium by Morteza Alizadeh et al., https://doi.org/10.1002/term.3150.

Skin is the body’s first barrier against external pathogens that maintains the homeostasis of the body. Any serious damage to the skin could have an impact on human health and quality of life. Tissue engineering aims to improve the quality of damaged tissue regeneration. One of the most effective treatments for skin tissue regeneration is to improv...

The aim of this study was evaluating the effects of vacuum on microstructure and biocompatibility of bovine decellularized pericardium. So the bovine pericardia were decellularized and then the vacuum was applied for two periods of time; 90 and 180 min. DNA, glucose amino glycan, collagen and elastin content assay, scanning electron microscopy (SEM...

Bone tissue engineering serves as a solution to repair and rebuild the damaged bone. In this study, first, the akermanite nanoparticles were synthesized by the sol-gel method; then the polylactic acid (PLA) scaffold was made using the fused deposition modelling (FDM), and the akermanite nanoparticle booster was used to improve its properties. The i...

Background: Skin, the first barrier to pathogens, loses its integrity and function after an injury. The presence of an antibacterial dressing at the wound site may prevent bacterial invasion and also improve the healing process. Objectives: The current study aimed to fabricate a biomimetic membrane with antibacterial properties for healing chron...

Anatase Rutile Apatite forming ability a b s t r a c t Hydrogen peroxide treatment is a cost-effective and simple method to improve the bioac-tivity of titanium implants. In this study, the effects of chloride ion concentration and temperature of hydrogen peroxide on the surface treatment of titanium were investigated using X-ray diffractometry (XR...

In this study, Poly Lactic Acid (PLA) scaffolds containing different amounts of akermanite (Ak) particles were prepared using the fused filament fabrication (FFF) technology. Ak particles were fabricated using sol-gel method. Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscopy (TEM) images revealed that the size...

The surface treatment is important for titanium and its alloys as promising candidates for dental implantation due to their bioinert surface. Titanium surface samples were modified using H2O2 solution at different times up to 72 h to boost their bioactivity. According to the results of the field emission scanning electron microscopy test, some nano...

In this study, magnesium scaffolds including 60% porosity were designed and fabricated using sucrose spacer agent by the powder metallurgy technique with the pore size of 400–600 μm with two biomimetic designs of the filled center design (FCD) and the hollow center design (HCD) for bone regeneration. The spacer agent was removed by distilled water...

Three-dimensional porous poly-lactic acid (PLA) scaffold was fabricated using fused deposition modeling (FDM) method including 30%, 50% and 70% nominal porosity. Study of phases in initial polymeric material and printed scaffolds was done by X-ray diffraction (XRD), and no significant phase difference was observed due to the manufacturing process,...

Nano-ceramic particles can serve as reinforcing agents for metallic materials to improve their mechanical properties. However, it is important to ensure chemical compatibility between the matrix and particles. In the present study, magnesium composites with and without nano-hydroxyapatite (nHA) particles were fabricated for bone reconstruction appl...

Abstract Background: This study aimed to evaluate the remineralization potential and bioactivity of adhesives, containing amorphous calcium phosphate (ACP) and calcium silicate (CS) nanoparticles (NPs). Material and methods: In this study, dentin slices (n=60) were prepared and etched with phosphoric acid. Next, they were divided into two groups: p...

Titanium is a highly reactive metal and its high-temperature processing has to be done at a high-vacuum atmosphere. In this research, porous titanium scaffolds were fabricated using the space holder method for dental reconstruction purposes. Accordingly, the samples were sintered in two different vacuum furnaces at the vacuum level of 0.013 Pa, inc...

Direct oxidation is a simple and effective method for titanium surface treatment. In this research, a titanium sample was directly oxidized at the high temperature in two different atmospheres, air and pure oxygen, to obtain better atmosphere for titanium surface treatment. The results of the Raman spectroscopy indicated that in both atmospheres, t...

Nowadays, due to a growing number of tissue injuries, in particular, skin wounds, induction and promotion of tissue healing responses can be considered as a crucial step towards a complete regeneration. Recently, biomaterial design has been oriented towards promoting a powerful, effective, and successful healing. Biomaterials with wound management...

Titanium and its alloys are well-known for superior properties, but they suffer from high elastic modulus and bio-inertness, which make porosification and surface treatment essential for them. In this study, porous titanium scaffold including 70 vol% nominal porosity was fabricated using space holder method and its surface was coated using forsteri...

Porous magnesium scaffolds have been of interest to tissue engineering researchers because of their biodegradability and biocompatibility. Space holder method is a simple method for fabrication these scaffolds, but suffer from clean spacer agent removal process. This study was conducted to introduce a modified dissolution method (Distilled water+HF...

In this research YVO4:Dy 3+ luminescent material was synthesized via a facile and one-step solid state method at 1100°C. Then, the effects of spherical and irregular SiO2 particles on microstructure and photoluminescence properties of the phosphors were studied in details. To study the microstructure and properties of these composites XRD, SEM, TEM...

Application of “bioactive materials”, as a modified version of biomaterials, can optimize the response of the biological system due to their surface reactivity and formation of strong interactions with the adjacent tissue upon implantation. However, choosing an appropriate bioactive material that suits to the application and provides the desired me...

The main purpose of this study was to fabricate a magnesium/nano-hydroxyapatite porous composite with appropriate mechanical properties and degradation rate for biomedical applications. Magnesium scaffolds including different weight of nano-hydroxyapatite (0, 2, 4 and 8%) were fabricated using the powder metallurgy method. To study the phase and mi...

In this work, functionally graded material (FGM) of Titanium/nano-hydroxyapatite were fabricated using powder metallurgy method as dental implant and their biocompatibility, static strength and fatigue characteristics in different volume fraction exponents were investigated using experimental and numerical methods. For producing hydroxyapatite powd...

Biodegradable scaffolds are essential parts in hard tissue engineering. A highly porous magnesium-zinc (Mg-Zn 4 wt.%) scaffold with different Mg-Zn powder to liquid media ratios (50 wt.%, 70 wt.% and 90 wt.%) and different concentrations of ethanol (0 vol.%, 10 vol.%, 20 vol.% and 40 vol.%) were prepared through modified replica method. The mechani...

Diffusion bonding, due to improving the dispersion of brittle intermetallic compounds, reducing the process energy and increasing the bonding strength of aluminum-magnesium joints, is widely used. In the present study, the commercially pure aluminum and magnesium bulks were successfully diffusion bonded at different strain values (0, 30 and 60%) at...

Amalgam was one of the most commonly used dental fill materials, and its usage is restricted in many countries, while amalgam is still under discussion by researchers. The alloy is criticized due to its mercury content and also its risks and limited resistance to corrosion in the body environment. In this study, amalgam/nano-hydroxyapatite composit...

The major disadvantage of titanium dental implants is their bio-inertness, which could be alleviated using surface treatment techniques. Oxidation using hydrogen peroxide (H2O2) was used for surface treatment of titanium dental implants in this study. The effect of some oxidizing ions such as Cl and F in addition to post-heat treatment was investig...

Reducing the elastic modulus and also improving biological fixation to the bone is possible by using porous scaffolds. In the present study, porous titanium scaffolds containing different porosities were fabricated using the space holder method. Pore distribution, formed phases and mechanical properties of titanium scaffolds were studied by Scannin...

Structural and mechanical properties of scaffolds are important for hard tissue reconstruction. In this study, magnesium scaffolds were fabricated using space holder method for bone tissue reconstruction and the effect of cold compaction pressure and also volume percent of porosity on structural and mechanical properties of scaffolds were investiga...

Titanium is considered a promising biomaterial for load bearing implantation in orthopedics. However, its biologically inert behavior makes the surface treatment essential to improve the bioactivity. In this study, a porous titanium scaffold was fabricated using the space holder method and its surface was treated by the direct oxidation method. Str...

The bioinertness makes surface treatments essential to improve the bioactivity of porous titanium scaffold, and surface treatment might affect their mechanical properties. So finding an optimum condition lying between bioactivity and mechanical properties seems to be curial. In this research, the effect of the time of the thermal oxidation at 600 °...

Because of the superior chemical and mechanical properties of titanium, many surface treatments have been developed to alleviate its bioactivity limitations. Among all these, the procedures involving the modification of the surface of the titanium using liquid media have received more attention, because of their ability to modify all outer and inne...

It has been tried to investigate the effect of heat treating surface modifications on surface properties of Ti6Al4V implant. Regarding to application of this alloy for bone healing porposes, and its excellent mechanical, chemical and physical (corrosion) properties in human tissue, in recent investigations, it has been tried to surface properties o...

In the present research we have applied three types of surface modifications on Ti6Al4 V alloy including heat treatment, H2O2 treatment and alkali treatment. Scanning electron microscope and thin-film X-ray diffractometry (TF-XRD) were used to analyse the surface structure and the formed phases on the surface modified specimens. In vitro bioactivit...