Hamed Nosrati - Academia.edu (original) (raw)

Papers by Hamed Nosrati

Elsevier, 2023

Wound care and treatment can be critical from a clinical standpoint. While different strategies f... more 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 of novel promising approaches for accelerating wound healing. The use of various biomaterials capable of accelerating the regeneration of damaged tissue is critical in tissue engineering. In this regard, cerium oxide nanoparticles (CeO 2 NPs) have recently received much attention because of their excellent biological properties, such as antibacterial, anti-inflammatory, antioxidant, and angiogenic features. The incorporation of CeO 2 NPs into various polymer-based scaffolds developed for wound healing applications has led to accelerated wound healing due to the presence of CeO 2 NPs. This paper discusses the structure and functions of the skin, the wound healing process, different methods for the synthesis of CeO 2 NPs, the biological properties of CeO 2 NPs, the role of CeO 2 NPs in wound healing, the use of scaffolds containing CeO 2 NPs for wound healing applications, and the potential toxicity of CeO 2 NPs.

MDPI, 2023

The field of regenerative medicine is constantly advancing and aims to repair, regenerate, or sub... more The field of regenerative medicine is constantly advancing and aims to repair, regenerate,
or substitute impaired or unhealthy tissues and organs using cutting-edge approaches such as stem
cell-based therapies, gene therapy, and tissue engineering. Nevertheless, incorporating artificial
intelligence (AI) technologies has opened new doors for research in this field. AI refers to the ability
of machines to perform tasks that typically require human intelligence in ways such as learning the
patterns in the data and applying that to the new data without being explicitly programmed. AI
has the potential to improve and accelerate various aspects of regenerative medicine research and
development, particularly, although not exclusively, when complex patterns are involved. This review
paper provides an overview of AI in the context of regenerative medicine, discusses its potential
applications with a focus on personalized medicine, and highlights the challenges and opportunities
in this field.

Journal of Biomedical Materials Research Part B: Applied Biomaterials

Chronic wounds are among the most therapeutically challenging conditions, which are commonly foll... more 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 several carriers developed for drug delivery. Moreover, advances in tissue engineering have resulted in new drug delivery systems that can improve the skin regeneration rate and quality. In this study, cefazolin-loaded niosomes were electrosprayed onto chitosan membrane for wound healing applications. For this purpose, niosomes were obtained by the thin-film hydration method; electrospinning was then conducted to fabricate nanofibrous mats. In vitro characterization of the scaffold was performed to evaluate the physicochemical and biological properties. Finally, in vivo studies were carried out to evaluate the potential use of the membrane for skin regeneration. In vitro results indicated the antibacterial properties of the membrane against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) due to the gradual release of cefazolin from niosomes. The scaffolds also showed no cell toxicity. In vivo studies also confirmed the ability of the membrane to enhance skin regeneration by improving re-epithelialization, tissue remodeling, and angiogenesis. The current study could well show the promising role of the prepared scaffold for skin regeneration and bacterial infection elimination.

Medical Hypotheses, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

International Journal of Biological Macromolecules, 2021

Today, chronic wound care and management can be regarded as a clinically critical issue. However,... more 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 approaches that can accelerate wound healing and improve the skin regeneration rate and quality. The design and fabrication of scaffolds that can address the multifactorial nature of chronic wound occurrence and provide support for the healing process can be considered an important area requiring improvement. In this regard, polysaccharide-based scaffolds have distinctive properties such as biocompatibility, biodegradability, high water retention capacity and nontoxicity, making them ideal for wound healing applications. Their tunable structure and networked morphology could facilitate a number of functions, such as controlling their diffusion, maintaining wound moisture, absorbing a large amount of exudates and facilitating gas exchange. In this review, the wound healing process and the influential factors, structure and properties of carbohydrate polymers, physical and chemical crosslinking of polysaccharides, scaffold fabrication techniques, and the use of polysaccharide-based scaffolds in skin tissue engineering and wound healing applications are discussed.

Polymers in Medicine, 2020

The stroma is one of the 5 layers of the cornea that comprises more than 90% of the corneal thick... more The stroma is one of the 5 layers of the cornea that comprises more than 90% of the corneal thickness, and is the most important layer for the transparency of cornea and refractive function critical for vision. Any significant damage to this layer may lead to corneal blindness. Corneal blindness refers to loss of vision or blindness caused by corneal diseases or damage, which is the 4 th most common cause of blindness worldwide. Different approaches are used to treat these patients. Severe corneal damage is traditionally treated by transplantation of a donor cornea or implantation of an artificial cornea. Other alternative approaches, such as cell/stem cell therapy, drug/gene delivery and tissue engineering, are currently promising in the regeneration of damaged cornea. The aim of tissue engineering is to functionally repair and regenerate damaged cornea using scaffolds with or without cells and growth factors. Among the different types of scaffolds, polymer-based scaffolds have shown great potential for corneal stromal regeneration. In this paper, the most recent findings of corneal stromal tissue engineering are reviewed.

Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2020

Dual-pump electrospinning of antibacterial N-decyl-N, N-dimethyl-1-decanaminium-chloride (DDAC)-l... more Dual-pump electrospinning of antibacterial N-decyl-N, N-dimethyl-1-decanaminium-chloride (DDAC)-loaded polycaprolactone (PCL) nanofibers, and chitosan (CS)/polyethylene-oxide (PEO)-based wound dressings with hydrophilic and hydrophobic properties to eliminate and absorb pathogenic bacteria from wound surface besides antibacterial action and to support wound healing and accelerate its process. Physicochemical properties of the prepared nanofibrous mat as well as antibacterial, cytotoxicity, and cell compatibility were studied. The full-thickness excisional wound healing properties up to 3 weeks using hematoxylin and eosin and Masson-trichrome staining were investigated. Addition of DDAC to CS/PEO-PCL mats decreased the diameter of the nanofibers, which is a crucial property for wound healing as large surface area per volume ratio of nanofibers, in addition to proper cell adhesion, increases loading of DDAC in mats and leads to increased cell viability and eliminating Gram-positive bacteria at in vitro studies. In vivo studies showed DDAC-loaded CS/PEO-PCL mats increased epithelialization and angiogenesis and decreased the inflammation according to histological results. We demonstrated that hydrophobic PCL/DDAC mats, besides antibacterial properties of DDAC, absorbed and eliminated the hydrophobic pathological microorganisms, whereas the hydrophilic nanofibers consisted of CS/PEO, increased the cell adhesion and proliferation due to positive charge of CS. Finally, we were able to increase the wound healing quality by using multifunctional wound dressing. CS/PEO-PCL containing 8 wt % of DDAC nanofibrous mats is promising as a wound dressing for wound management due to the favorable interactions between the pathogenic bacteria and PCL/CS-based wound dressing.

Tissue and Cell, 2021

Atomistic and coarse-grained simulations can be a great help in uncovering the mechanisms of phys... more Atomistic and coarse-grained simulations can be a great help in uncovering the mechanisms of physical processes at microscopic and mesoscopic levels at time scales ranging from femtoseconds to milliseconds. Any simulation study involves (1) setting up an appropriate simulation system representing the physical problem, (2) running the simulation and collecting information about the system, and (3) analyzing the collected data. The last step eventually leads to final conclusions about the system. Software for molecular simulation has been in development for many years and a number of high quality freely distributed general purpose simulation packages is available for researchers. Data analysis tools are usually less general as they often depend on a specific research project and the system under investigation. While many simulation packages come with a set of some general data analysis utilities, it is not unusual for such analysis tools to be developed on a per project basis inside research groups. Interestingly, there is a very limited set of available tools for setting up simulation systems, even though this is the very first and vital step of every simulation study. This lack of convenient general simulation system generators sometimes may even dictate the kind of simulations done based on the available initial systems rather than on the system being the best for a particular problem. In this work we describe a general software tool, bio.b-gen, for the creation of initial systems for biological molecular simulations. A number of case systems are demonstrated using an atomistic force field as well as the coarse grained MARTINI force field. The tool is designed to generate initial systems for the GROMACS general simulation package.

Applied Surface Science, 2019

The main objective of this study is to hydrophobize nitinol (Ni-Ti alloy) for cardiovascular appl... more The main objective of this study is to hydrophobize nitinol (Ni-Ti alloy) for cardiovascular applications. For this purpose, medical nitinol samples were subjected to sodium hydroxide hydrothermal treatments at various temperatures, followed by hexadecyltrimethoxysilane (HDTMS) functionalization. Then, the structure, wettability, corrosion, cytocompatibility and cell adhesion of the prepared samples were evaluated. According to the results, porous blade-shaped layers of sodium titanate were formed on the substrate surface as a result of the alkaline treatment. These nano-rough features offered considerable hydrophobicity after HDTMS processing, where a maximum water contact angle of about 140° was obtained for the sample treated at 120 °C, followed by the HDTMS coating. In contrast to the individual application of the alkaline treatments, the subsequent HDTMS processing improved corrosion resistance in the simulated body fluid. Although all the samples presented appropriate cytocompatibility with respect to human umbilical vein endothelial cells, the cells did not show an adhesion tendency to the hydrophobic surfaces. It is concluded that alkaline hydrothermal and HDTMS processed nitinol can be considered for cardiovascular applications demanding hydrophobic surfaces.

Regenerative Medicine, 2020

Currently, many corneal diseases are treated by corneal transplantation, artificial corneal impla... more Currently, many corneal diseases are treated by corneal transplantation, artificial corneal implantation or, in severe cases, keratoprosthesis. Owing to the shortage of cornea donors and the risks involved with artificial corneal implants, such as infection transmission, researchers continually seek new approaches for corneal regeneration. Corneal tissue engineering is a promising approach that has attracted much attention from researchers and is focused on regenerative strategies using various biomaterials in combination with different cell types. These constructs should have the ability to mimic the native tissue microenvironment and present suitable optical, mechanical and biological properties. In this article, we review studies that have focused on the current clinical techniques for corneal replacement. We also describe tissue-engineering and cell-based approaches for corneal regeneration.

Journal of Nanobiotechnology

Skin is the body’s first barrier against external pathogens that maintains the homeostasis of the... more 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 improve angiogenesis during the healing period. Over the last decade, there has been an impressive growth of new potential applications for nanobiomaterials in tissue engineering. Various approaches have been developed to improve the rate and quality of the healing process using angiogenic nanomaterials. In this review, we focused on molecular mechanisms and key factors in angiogenesis, the role of nanobiomaterials in angiogenesis, and scaffold-based tissue engineering approaches for accelerated wound healing based on improved angiogenesis.

International Journal of Biological Macromolecules

Natural polymer-based scaffolds can increase cell affinity to biomaterials and improve cell respo... more Natural polymer-based scaffolds can increase cell affinity to biomaterials and improve cell responses. Silk fibroin, chitosan and gelatin that mimic the properties of natural extra-cellular matrix (ECM) were chosen due to their biocompatibility, biodegradability and less immunogenic reactions. We prepared composite scaffolds with different blending ratios of silk fibroin-chitosan-gelatin by freeze-drying technique. Silk fibroin was extracted from the Bombyx mori silkworm. The scaffolds were characterized by scanning electron microscopy (SEM), surface wet-tability, swelling measurements, In Vitro enzymatic degradation measurements and tensile test. The composite scaffolds showed pore sizes from 125 μm to 175 μm, good interconnectivity between pores and suitable porosity which are desirable for cell growth. The addition of chitosan-gelatin to silk fibroin increased water uptake and degradation rate and reduced mechanical strength but silk fibroin affect reversely on the degradation and mechanical strength of composite scaffolds. Biocompatibility of scaffolds was demonstrated by MTT-assay and hematoxylin-eosin (H&E) staining which lead to the growth and adhesion of endothelial cells. In this study, the fabricated composite scaffolds have the potential for tissue engineering applications.

BMC Nephrology

Background Silver nanoparticles (AgNPs) can accumulate in various organs after oral exposure. The... more Background Silver nanoparticles (AgNPs) can accumulate in various organs after oral exposure. The main objective of the current study is to evaluate the renal toxicity induced by AgNPs after repeated oral exposure and to determine the relevant molecular mechanisms. Methods In this study, 40 male Wistar rats were treated with solutions containing 30, 125, 300, and 700 mg/kg of AgNPs. After 28 days of exposure, histopathological changes were assessed using hematoxylin-eosin (H&E), Masson’s trichrome, and periodic acid-Schiff (PAS) staining. Apoptosis was quantified by TUNEL and immunohistochemistry of caspase-3, and the level of expression of the mRNAs of growth factors was determined using RT-PCR. Results Histopathologic examination revealed degenerative changes in the glomeruli, loss of tubular architecture, loss of brush border, and interrupted tubular basal laminae. These changes were more noticeable in groups treated with 30 and 125 mg/kg. The collagen intensity increased in the ...

Future Medicine, 2020

Currently, many corneal diseases are treated by corneal transplantation, artificial corneal impla... more Currently, many corneal diseases are treated by corneal transplantation, artificial corneal implantation or, in severe cases, keratoprosthesis. Owing to the shortage of cornea donors and the risks involved with artificial corneal implants, such as infection transmission, researchers continually seek new approaches for corneal regeneration. Corneal tissue engineering is a promising approach that has attracted much attention from researchers and is focused on regenerative strategies using various biomaterials in combination with different cell types. These constructs should have the ability to mimic the native tissue microenvironment and present suitable optical, mechanical and biological properties. In this article, we review studies that have focused on the current clinical techniques for corneal replacement. We also describe
tissue-engineering and cell-based approaches for corneal regeneration.

Churchill Livingstone, 2021

Any significant loss of vision or blindness caused by corneal damages is referred to as corneal b... more 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 artificial cornea (keratoprosthesis) is suggested after a patient has had a donor corneal transplant failure. The shortage of donors and the side effects of keratoprosthesis are limiting these approaches. Recently, researchers have been actively pursuing new approaches for corneal regeneration because of these limitations. Nowadays, tissue engineering of different corneal layers (epithelium, stroma, endothelium, or full thickness tissue) is a promising approach that has attracted a great deal of interest from researchers and focuses on regenerative strategies using different cell sources and biomaterials. Various sources of corneal and non-corneal stem cells have shown significant advantages for corneal epithelium regeneration applications. Pluripotent stem cells (embryonic stem cells and iPS cells), epithelial stem cells (derived from oral mucus, amniotic membrane, epidermis and hair follicle), mesenchymal stem cells (bone marrow, adipose-derived, amniotic membrane, placenta, umbilical cord), and neural crest origin stem cells (dental pulp stem cells) are the most promising sources in this regard. These cells could also be used in combination with natural or synthetic scaffolds to improve the efficacy of the therapeutic approach. As the ocular surface is exposed to external damage, the number of studies on regeneration of the corneal epithelium is rising. In this paper, we reviewed the stem cell-based strategies for corneal epithelium regeneration.

The stroma is one of the 5 layers of the cornea that comprises more than 90% of the corneal thick... more The stroma is one of the 5 layers of the cornea that comprises more than 90% of the corneal thickness, and is the most important layer for the transparency of cornea and refractive function critical for vision. Any significant damage to this layer may lead to corneal blindness. Corneal blindness refers to loss of vision or blindness caused by corneal diseases or damage, which is the 4 th most common cause of blindness worldwide. Different approaches are used to treat these patients. Severe corneal damage is traditionally treated by transplantation of a donor cornea or implantation of an artificial cornea. Other alternative approaches, such as cell/stem cell therapy, drug/gene delivery and tissue engineering, are currently promising in the regeneration of damaged cornea. The aim of tissue engineering is to functionally repair and regenerate damaged cornea using scaffolds with or without cells and growth factors. Among the different types of scaffolds, polymer-based scaffolds have shown great potential for corneal stromal regeneration. In this paper, the most recent findings of corneal stromal tissue engineering are reviewed.

Background. Skin, the first barrier to pathogens, loses its integrity and function after an injur... more 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 chronic wounds.
Material and methods. The membranes, fabricated through electrospinning, are comprised of poly(ethylene oxide) (PEO) and zinc oxide nanoparticles (ZnO-NPs) as the main biomaterial and antibacterial agent, respectively. Antibacterial activity, cell attachment and viability were tested to evaluate the biological properties of the membranes. The optimal cell compatible concentration of ZnO-NPs was determined for further studies. In vitro characterization of the membranes was performed to confirm their suitable properties for wound healing.
Results. The antibacterial PEO/ZnO-NP membrane containing 2% of nanoparticles showed no cell toxicity, and human fibroblast cells were able to adhere and proliferate on the scaffold. The in vitro results from the tensile test, wettability, porosity, and protein adsorption revealed appropriate properties of the membrane as a scaffold for skin tissue engineering.
Conclusions. Synthetic polymers have been widely used for tissue engineering applications. The proper characteristics of PEO nanofibers, including a high ratio of surface/volume, moderate hydrophilicity and good mechanical properties, make this polymer interesting for skin regeneration. The results demonstrate the potential of the antibacterial PEO/ZnO-NP membrane to be used as an engineered scaffold to improve the wound healing process.

Cold Spring Harbor Laboratory, 2018

Background This investigation is concentrated on how hematological and serum biochemical markers ... more Background This investigation is concentrated on how hematological and serum biochemical markers would change in streptozotocin-induced Insulin-Dependent diabetes mellitus(IDDM) in male adult wistar rats. Hematological parameters, serum protein electrophoresis parameters and hepatic transaminases level (SGOT-SGPT) were all measured in both control group rats (N=6) and diabetic group rats (N=6) and comparison between two groups was performed. Material and Method Single dose intraperitoneal injection of 60 mg/kg dose of streptozotocin(STZ) in male adult wistar rats, induces extensive necrosis in langerhans β-cell islets, because of its cytotoxicity. Experimental diabetes mellitus can be induced completely in less than 72 hours after STZ intraperitoneal injection. Streptozotocin(STZ) was purchased from Sigma company. Diabetic and control group rats were kept separately in different metabolic cages, and their blood glucose(BG), hematological parameters, serum protein electrophoretic pattern and hepatic transaminases level were analyzed and comparison was done. Results In our investigation, Insulin-Dependent Diabetes Mellitus(IDDM) was completely induced one week after single intraperitoneal injection of 60 mg/kg BW. Diabetes mellitus induction was verified by measuring fasting plasma glucose level in blood samples of rats. Level of blood glucose, hematological parameters, serum protein electrophoretic pattern and hepatic transaminase enzymes level, were all measured. In diabetic group rats level of blood glucose (BG), hepatic transaminase enzymes (SGOT & SGPT), serum α 1-globulin and β-globulin were significantly increased but in albumin, albumin/globulin ratio (A/G ratio) and serum α 2-globulin a significant decrease was observed in diabetic rats in comparison with normal rats. Conclusion Extensive inflammation and tissue necrosis induced following diabetes mellitus induction in rats. Significant alterations were observed in serum protein electrophoresis fractions and hepatic transaminase enzymes level due to streptozotocin cytotoxic impacts on some tissues specifically liver. Because of extensive β-cells necrosis and degeneration caused by streptozotocin exposure, high level of blood glucose(diabetic hyperglycemia) was observed in diabetic rats. This type of experimentally induced diabetes mellitus would highly affect hematological parameters. Insulin-Dependent Diabetes Mellitus induced by streptozotocin, can lead to anemia, neutrophilia and lymphocytosis and also has decreasing effects on red blood cell indices (HGB, MCV, MCH, MCHC) in diabetic group rats. certified by peer review)

Elsevier, 2020

Nowadays, because of the resistance of bacteria to antibiotics, researchers are trying to make ne... more Nowadays, because of the resistance of bacteria to antibiotics, researchers are trying to make new antibiotics or sometimes even bring them back into the treatment cycle so that they could eliminate the bacteria’s resistance. On the other hand, the use of nanofibers has become widespread in many fields for their unique properties and convenient design. The present study focuses on the production of hydrophobic nanofibers to absorb the bacteria and their toxins from the bloodstream that contains the infection. Many bacterial surfaces have hydrophobic surfactant properties due to hydrophobic surface protein. According to the principle of binding two hydrophobic molecules to each other in an aqueous medium, the nanofibers are designed to physically absorb the bacteria. The use of antibiotics in the study can remove some unattached bacteria. In addition, using nanofiber manufacturing techniques can reduce the resistance of bacteria to antibiotics. The construction of the desired membrane can be used in subsequent studies as a replacement membrane for dialysis filters.

Elsevier, 2023

Wound care and treatment can be critical from a clinical standpoint. While different strategies f... more 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 of novel promising approaches for accelerating wound healing. The use of various biomaterials capable of accelerating the regeneration of damaged tissue is critical in tissue engineering. In this regard, cerium oxide nanoparticles (CeO 2 NPs) have recently received much attention because of their excellent biological properties, such as antibacterial, anti-inflammatory, antioxidant, and angiogenic features. The incorporation of CeO 2 NPs into various polymer-based scaffolds developed for wound healing applications has led to accelerated wound healing due to the presence of CeO 2 NPs. This paper discusses the structure and functions of the skin, the wound healing process, different methods for the synthesis of CeO 2 NPs, the biological properties of CeO 2 NPs, the role of CeO 2 NPs in wound healing, the use of scaffolds containing CeO 2 NPs for wound healing applications, and the potential toxicity of CeO 2 NPs.

MDPI, 2023

The field of regenerative medicine is constantly advancing and aims to repair, regenerate, or sub... more The field of regenerative medicine is constantly advancing and aims to repair, regenerate,
or substitute impaired or unhealthy tissues and organs using cutting-edge approaches such as stem
cell-based therapies, gene therapy, and tissue engineering. Nevertheless, incorporating artificial
intelligence (AI) technologies has opened new doors for research in this field. AI refers to the ability
of machines to perform tasks that typically require human intelligence in ways such as learning the
patterns in the data and applying that to the new data without being explicitly programmed. AI
has the potential to improve and accelerate various aspects of regenerative medicine research and
development, particularly, although not exclusively, when complex patterns are involved. This review
paper provides an overview of AI in the context of regenerative medicine, discusses its potential
applications with a focus on personalized medicine, and highlights the challenges and opportunities
in this field.

Journal of Biomedical Materials Research Part B: Applied Biomaterials

Chronic wounds are among the most therapeutically challenging conditions, which are commonly foll... more 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 several carriers developed for drug delivery. Moreover, advances in tissue engineering have resulted in new drug delivery systems that can improve the skin regeneration rate and quality. In this study, cefazolin-loaded niosomes were electrosprayed onto chitosan membrane for wound healing applications. For this purpose, niosomes were obtained by the thin-film hydration method; electrospinning was then conducted to fabricate nanofibrous mats. In vitro characterization of the scaffold was performed to evaluate the physicochemical and biological properties. Finally, in vivo studies were carried out to evaluate the potential use of the membrane for skin regeneration. In vitro results indicated the antibacterial properties of the membrane against Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) due to the gradual release of cefazolin from niosomes. The scaffolds also showed no cell toxicity. In vivo studies also confirmed the ability of the membrane to enhance skin regeneration by improving re-epithelialization, tissue remodeling, and angiogenesis. The current study could well show the promising role of the prepared scaffold for skin regeneration and bacterial infection elimination.

Medical Hypotheses, 2020

This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

International Journal of Biological Macromolecules, 2021

Today, chronic wound care and management can be regarded as a clinically critical issue. However,... more 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 approaches that can accelerate wound healing and improve the skin regeneration rate and quality. The design and fabrication of scaffolds that can address the multifactorial nature of chronic wound occurrence and provide support for the healing process can be considered an important area requiring improvement. In this regard, polysaccharide-based scaffolds have distinctive properties such as biocompatibility, biodegradability, high water retention capacity and nontoxicity, making them ideal for wound healing applications. Their tunable structure and networked morphology could facilitate a number of functions, such as controlling their diffusion, maintaining wound moisture, absorbing a large amount of exudates and facilitating gas exchange. In this review, the wound healing process and the influential factors, structure and properties of carbohydrate polymers, physical and chemical crosslinking of polysaccharides, scaffold fabrication techniques, and the use of polysaccharide-based scaffolds in skin tissue engineering and wound healing applications are discussed.

Polymers in Medicine, 2020

The stroma is one of the 5 layers of the cornea that comprises more than 90% of the corneal thick... more The stroma is one of the 5 layers of the cornea that comprises more than 90% of the corneal thickness, and is the most important layer for the transparency of cornea and refractive function critical for vision. Any significant damage to this layer may lead to corneal blindness. Corneal blindness refers to loss of vision or blindness caused by corneal diseases or damage, which is the 4 th most common cause of blindness worldwide. Different approaches are used to treat these patients. Severe corneal damage is traditionally treated by transplantation of a donor cornea or implantation of an artificial cornea. Other alternative approaches, such as cell/stem cell therapy, drug/gene delivery and tissue engineering, are currently promising in the regeneration of damaged cornea. The aim of tissue engineering is to functionally repair and regenerate damaged cornea using scaffolds with or without cells and growth factors. Among the different types of scaffolds, polymer-based scaffolds have shown great potential for corneal stromal regeneration. In this paper, the most recent findings of corneal stromal tissue engineering are reviewed.

Journal of Biomedical Materials Research Part B: Applied Biomaterials, 2020

Dual-pump electrospinning of antibacterial N-decyl-N, N-dimethyl-1-decanaminium-chloride (DDAC)-l... more Dual-pump electrospinning of antibacterial N-decyl-N, N-dimethyl-1-decanaminium-chloride (DDAC)-loaded polycaprolactone (PCL) nanofibers, and chitosan (CS)/polyethylene-oxide (PEO)-based wound dressings with hydrophilic and hydrophobic properties to eliminate and absorb pathogenic bacteria from wound surface besides antibacterial action and to support wound healing and accelerate its process. Physicochemical properties of the prepared nanofibrous mat as well as antibacterial, cytotoxicity, and cell compatibility were studied. The full-thickness excisional wound healing properties up to 3 weeks using hematoxylin and eosin and Masson-trichrome staining were investigated. Addition of DDAC to CS/PEO-PCL mats decreased the diameter of the nanofibers, which is a crucial property for wound healing as large surface area per volume ratio of nanofibers, in addition to proper cell adhesion, increases loading of DDAC in mats and leads to increased cell viability and eliminating Gram-positive bacteria at in vitro studies. In vivo studies showed DDAC-loaded CS/PEO-PCL mats increased epithelialization and angiogenesis and decreased the inflammation according to histological results. We demonstrated that hydrophobic PCL/DDAC mats, besides antibacterial properties of DDAC, absorbed and eliminated the hydrophobic pathological microorganisms, whereas the hydrophilic nanofibers consisted of CS/PEO, increased the cell adhesion and proliferation due to positive charge of CS. Finally, we were able to increase the wound healing quality by using multifunctional wound dressing. CS/PEO-PCL containing 8 wt % of DDAC nanofibrous mats is promising as a wound dressing for wound management due to the favorable interactions between the pathogenic bacteria and PCL/CS-based wound dressing.

Tissue and Cell, 2021

Atomistic and coarse-grained simulations can be a great help in uncovering the mechanisms of phys... more Atomistic and coarse-grained simulations can be a great help in uncovering the mechanisms of physical processes at microscopic and mesoscopic levels at time scales ranging from femtoseconds to milliseconds. Any simulation study involves (1) setting up an appropriate simulation system representing the physical problem, (2) running the simulation and collecting information about the system, and (3) analyzing the collected data. The last step eventually leads to final conclusions about the system. Software for molecular simulation has been in development for many years and a number of high quality freely distributed general purpose simulation packages is available for researchers. Data analysis tools are usually less general as they often depend on a specific research project and the system under investigation. While many simulation packages come with a set of some general data analysis utilities, it is not unusual for such analysis tools to be developed on a per project basis inside research groups. Interestingly, there is a very limited set of available tools for setting up simulation systems, even though this is the very first and vital step of every simulation study. This lack of convenient general simulation system generators sometimes may even dictate the kind of simulations done based on the available initial systems rather than on the system being the best for a particular problem. In this work we describe a general software tool, bio.b-gen, for the creation of initial systems for biological molecular simulations. A number of case systems are demonstrated using an atomistic force field as well as the coarse grained MARTINI force field. The tool is designed to generate initial systems for the GROMACS general simulation package.

Applied Surface Science, 2019

The main objective of this study is to hydrophobize nitinol (Ni-Ti alloy) for cardiovascular appl... more The main objective of this study is to hydrophobize nitinol (Ni-Ti alloy) for cardiovascular applications. For this purpose, medical nitinol samples were subjected to sodium hydroxide hydrothermal treatments at various temperatures, followed by hexadecyltrimethoxysilane (HDTMS) functionalization. Then, the structure, wettability, corrosion, cytocompatibility and cell adhesion of the prepared samples were evaluated. According to the results, porous blade-shaped layers of sodium titanate were formed on the substrate surface as a result of the alkaline treatment. These nano-rough features offered considerable hydrophobicity after HDTMS processing, where a maximum water contact angle of about 140° was obtained for the sample treated at 120 °C, followed by the HDTMS coating. In contrast to the individual application of the alkaline treatments, the subsequent HDTMS processing improved corrosion resistance in the simulated body fluid. Although all the samples presented appropriate cytocompatibility with respect to human umbilical vein endothelial cells, the cells did not show an adhesion tendency to the hydrophobic surfaces. It is concluded that alkaline hydrothermal and HDTMS processed nitinol can be considered for cardiovascular applications demanding hydrophobic surfaces.

Regenerative Medicine, 2020

Currently, many corneal diseases are treated by corneal transplantation, artificial corneal impla... more Currently, many corneal diseases are treated by corneal transplantation, artificial corneal implantation or, in severe cases, keratoprosthesis. Owing to the shortage of cornea donors and the risks involved with artificial corneal implants, such as infection transmission, researchers continually seek new approaches for corneal regeneration. Corneal tissue engineering is a promising approach that has attracted much attention from researchers and is focused on regenerative strategies using various biomaterials in combination with different cell types. These constructs should have the ability to mimic the native tissue microenvironment and present suitable optical, mechanical and biological properties. In this article, we review studies that have focused on the current clinical techniques for corneal replacement. We also describe tissue-engineering and cell-based approaches for corneal regeneration.

Journal of Nanobiotechnology

Skin is the body’s first barrier against external pathogens that maintains the homeostasis of the... more 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 improve angiogenesis during the healing period. Over the last decade, there has been an impressive growth of new potential applications for nanobiomaterials in tissue engineering. Various approaches have been developed to improve the rate and quality of the healing process using angiogenic nanomaterials. In this review, we focused on molecular mechanisms and key factors in angiogenesis, the role of nanobiomaterials in angiogenesis, and scaffold-based tissue engineering approaches for accelerated wound healing based on improved angiogenesis.

International Journal of Biological Macromolecules

Natural polymer-based scaffolds can increase cell affinity to biomaterials and improve cell respo... more Natural polymer-based scaffolds can increase cell affinity to biomaterials and improve cell responses. Silk fibroin, chitosan and gelatin that mimic the properties of natural extra-cellular matrix (ECM) were chosen due to their biocompatibility, biodegradability and less immunogenic reactions. We prepared composite scaffolds with different blending ratios of silk fibroin-chitosan-gelatin by freeze-drying technique. Silk fibroin was extracted from the Bombyx mori silkworm. The scaffolds were characterized by scanning electron microscopy (SEM), surface wet-tability, swelling measurements, In Vitro enzymatic degradation measurements and tensile test. The composite scaffolds showed pore sizes from 125 μm to 175 μm, good interconnectivity between pores and suitable porosity which are desirable for cell growth. The addition of chitosan-gelatin to silk fibroin increased water uptake and degradation rate and reduced mechanical strength but silk fibroin affect reversely on the degradation and mechanical strength of composite scaffolds. Biocompatibility of scaffolds was demonstrated by MTT-assay and hematoxylin-eosin (H&E) staining which lead to the growth and adhesion of endothelial cells. In this study, the fabricated composite scaffolds have the potential for tissue engineering applications.

BMC Nephrology

Background Silver nanoparticles (AgNPs) can accumulate in various organs after oral exposure. The... more Background Silver nanoparticles (AgNPs) can accumulate in various organs after oral exposure. The main objective of the current study is to evaluate the renal toxicity induced by AgNPs after repeated oral exposure and to determine the relevant molecular mechanisms. Methods In this study, 40 male Wistar rats were treated with solutions containing 30, 125, 300, and 700 mg/kg of AgNPs. After 28 days of exposure, histopathological changes were assessed using hematoxylin-eosin (H&E), Masson’s trichrome, and periodic acid-Schiff (PAS) staining. Apoptosis was quantified by TUNEL and immunohistochemistry of caspase-3, and the level of expression of the mRNAs of growth factors was determined using RT-PCR. Results Histopathologic examination revealed degenerative changes in the glomeruli, loss of tubular architecture, loss of brush border, and interrupted tubular basal laminae. These changes were more noticeable in groups treated with 30 and 125 mg/kg. The collagen intensity increased in the ...

Future Medicine, 2020

Currently, many corneal diseases are treated by corneal transplantation, artificial corneal impla... more Currently, many corneal diseases are treated by corneal transplantation, artificial corneal implantation or, in severe cases, keratoprosthesis. Owing to the shortage of cornea donors and the risks involved with artificial corneal implants, such as infection transmission, researchers continually seek new approaches for corneal regeneration. Corneal tissue engineering is a promising approach that has attracted much attention from researchers and is focused on regenerative strategies using various biomaterials in combination with different cell types. These constructs should have the ability to mimic the native tissue microenvironment and present suitable optical, mechanical and biological properties. In this article, we review studies that have focused on the current clinical techniques for corneal replacement. We also describe
tissue-engineering and cell-based approaches for corneal regeneration.

Churchill Livingstone, 2021

Any significant loss of vision or blindness caused by corneal damages is referred to as corneal b... more 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 artificial cornea (keratoprosthesis) is suggested after a patient has had a donor corneal transplant failure. The shortage of donors and the side effects of keratoprosthesis are limiting these approaches. Recently, researchers have been actively pursuing new approaches for corneal regeneration because of these limitations. Nowadays, tissue engineering of different corneal layers (epithelium, stroma, endothelium, or full thickness tissue) is a promising approach that has attracted a great deal of interest from researchers and focuses on regenerative strategies using different cell sources and biomaterials. Various sources of corneal and non-corneal stem cells have shown significant advantages for corneal epithelium regeneration applications. Pluripotent stem cells (embryonic stem cells and iPS cells), epithelial stem cells (derived from oral mucus, amniotic membrane, epidermis and hair follicle), mesenchymal stem cells (bone marrow, adipose-derived, amniotic membrane, placenta, umbilical cord), and neural crest origin stem cells (dental pulp stem cells) are the most promising sources in this regard. These cells could also be used in combination with natural or synthetic scaffolds to improve the efficacy of the therapeutic approach. As the ocular surface is exposed to external damage, the number of studies on regeneration of the corneal epithelium is rising. In this paper, we reviewed the stem cell-based strategies for corneal epithelium regeneration.

The stroma is one of the 5 layers of the cornea that comprises more than 90% of the corneal thick... more The stroma is one of the 5 layers of the cornea that comprises more than 90% of the corneal thickness, and is the most important layer for the transparency of cornea and refractive function critical for vision. Any significant damage to this layer may lead to corneal blindness. Corneal blindness refers to loss of vision or blindness caused by corneal diseases or damage, which is the 4 th most common cause of blindness worldwide. Different approaches are used to treat these patients. Severe corneal damage is traditionally treated by transplantation of a donor cornea or implantation of an artificial cornea. Other alternative approaches, such as cell/stem cell therapy, drug/gene delivery and tissue engineering, are currently promising in the regeneration of damaged cornea. The aim of tissue engineering is to functionally repair and regenerate damaged cornea using scaffolds with or without cells and growth factors. Among the different types of scaffolds, polymer-based scaffolds have shown great potential for corneal stromal regeneration. In this paper, the most recent findings of corneal stromal tissue engineering are reviewed.

Background. Skin, the first barrier to pathogens, loses its integrity and function after an injur... more 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 chronic wounds.
Material and methods. The membranes, fabricated through electrospinning, are comprised of poly(ethylene oxide) (PEO) and zinc oxide nanoparticles (ZnO-NPs) as the main biomaterial and antibacterial agent, respectively. Antibacterial activity, cell attachment and viability were tested to evaluate the biological properties of the membranes. The optimal cell compatible concentration of ZnO-NPs was determined for further studies. In vitro characterization of the membranes was performed to confirm their suitable properties for wound healing.
Results. The antibacterial PEO/ZnO-NP membrane containing 2% of nanoparticles showed no cell toxicity, and human fibroblast cells were able to adhere and proliferate on the scaffold. The in vitro results from the tensile test, wettability, porosity, and protein adsorption revealed appropriate properties of the membrane as a scaffold for skin tissue engineering.
Conclusions. Synthetic polymers have been widely used for tissue engineering applications. The proper characteristics of PEO nanofibers, including a high ratio of surface/volume, moderate hydrophilicity and good mechanical properties, make this polymer interesting for skin regeneration. The results demonstrate the potential of the antibacterial PEO/ZnO-NP membrane to be used as an engineered scaffold to improve the wound healing process.

Cold Spring Harbor Laboratory, 2018

Background This investigation is concentrated on how hematological and serum biochemical markers ... more Background This investigation is concentrated on how hematological and serum biochemical markers would change in streptozotocin-induced Insulin-Dependent diabetes mellitus(IDDM) in male adult wistar rats. Hematological parameters, serum protein electrophoresis parameters and hepatic transaminases level (SGOT-SGPT) were all measured in both control group rats (N=6) and diabetic group rats (N=6) and comparison between two groups was performed. Material and Method Single dose intraperitoneal injection of 60 mg/kg dose of streptozotocin(STZ) in male adult wistar rats, induces extensive necrosis in langerhans β-cell islets, because of its cytotoxicity. Experimental diabetes mellitus can be induced completely in less than 72 hours after STZ intraperitoneal injection. Streptozotocin(STZ) was purchased from Sigma company. Diabetic and control group rats were kept separately in different metabolic cages, and their blood glucose(BG), hematological parameters, serum protein electrophoretic pattern and hepatic transaminases level were analyzed and comparison was done. Results In our investigation, Insulin-Dependent Diabetes Mellitus(IDDM) was completely induced one week after single intraperitoneal injection of 60 mg/kg BW. Diabetes mellitus induction was verified by measuring fasting plasma glucose level in blood samples of rats. Level of blood glucose, hematological parameters, serum protein electrophoretic pattern and hepatic transaminase enzymes level, were all measured. In diabetic group rats level of blood glucose (BG), hepatic transaminase enzymes (SGOT & SGPT), serum α 1-globulin and β-globulin were significantly increased but in albumin, albumin/globulin ratio (A/G ratio) and serum α 2-globulin a significant decrease was observed in diabetic rats in comparison with normal rats. Conclusion Extensive inflammation and tissue necrosis induced following diabetes mellitus induction in rats. Significant alterations were observed in serum protein electrophoresis fractions and hepatic transaminase enzymes level due to streptozotocin cytotoxic impacts on some tissues specifically liver. Because of extensive β-cells necrosis and degeneration caused by streptozotocin exposure, high level of blood glucose(diabetic hyperglycemia) was observed in diabetic rats. This type of experimentally induced diabetes mellitus would highly affect hematological parameters. Insulin-Dependent Diabetes Mellitus induced by streptozotocin, can lead to anemia, neutrophilia and lymphocytosis and also has decreasing effects on red blood cell indices (HGB, MCV, MCH, MCHC) in diabetic group rats. certified by peer review)

Elsevier, 2020

Nowadays, because of the resistance of bacteria to antibiotics, researchers are trying to make ne... more Nowadays, because of the resistance of bacteria to antibiotics, researchers are trying to make new antibiotics or sometimes even bring them back into the treatment cycle so that they could eliminate the bacteria’s resistance. On the other hand, the use of nanofibers has become widespread in many fields for their unique properties and convenient design. The present study focuses on the production of hydrophobic nanofibers to absorb the bacteria and their toxins from the bloodstream that contains the infection. Many bacterial surfaces have hydrophobic surfactant properties due to hydrophobic surface protein. According to the principle of binding two hydrophobic molecules to each other in an aqueous medium, the nanofibers are designed to physically absorb the bacteria. The use of antibiotics in the study can remove some unattached bacteria. In addition, using nanofiber manufacturing techniques can reduce the resistance of bacteria to antibiotics. The construction of the desired membrane can be used in subsequent studies as a replacement membrane for dialysis filters.