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    Prevascularized micro-/nano-sized spheroid/bead aggregates for vascular tissue engineering

    , Article Nano-Micro Letters ; Volume 13, Issue 1 , 2021 ; 23116706 (ISSN) Rahimnejad, M ; Nasrollahi Boroujeni, N ; Jahangiri, S ; Rabiee, N ; Rabiee, M ; Makvandi, P ; Akhavan, O ; Varma, R. S ; Sharif University of Technology
    Springer Science and Business Media B.V  2021
    Abstract
    Efficient strategies to promote microvascularization in vascular tissue engineering, a central priority in regenerative medicine, are still scarce; nano- and micro-sized aggregates and spheres or beads harboring primitive microvascular beds are promising methods in vascular tissue engineering. Capillaries are the smallest type and in numerous blood vessels, which are distributed densely in cardiovascular system. To mimic this microvascular network, specific cell components and proangiogenic factors are required. Herein, advanced biofabrication methods in microvascular engineering, including extrusion-based and droplet-based bioprinting, Kenzan, and biogripper approaches, are deliberated with... 

    Melt electrowriting of PLA, PCL, and composite PLA/PCL scaffolds for tissue engineering application

    , Article Scientific Reports ; Volume 12, Issue 1 , 2022 ; 20452322 (ISSN) Shahverdi, M ; Seifi, S ; Akbari, A ; Mohammadi, K ; Shamloo, A ; Movahhedy, M. R ; Sharif University of Technology
    Nature Research  2022
    Abstract
    Fabrication of well-ordered and bio-mimetic scaffolds is one of the most important research lines in tissue engineering. Different techniques have been utilized to achieve this goal, however, each method has its own disadvantages. Recently, melt electrowriting (MEW) as a technique for fabrication of well-organized scaffolds has attracted the researchers’ attention due to simultaneous use of principles of additive manufacturing and electrohydrodynamic phenomena. In previous research studies, polycaprolactone (PCL) has been mostly used in MEW process. PCL is a biocompatible polymer with characteristics that make it easy to fabricate well-arranged structures using MEW device. However, the... 

    Fabrication of a novel 3D scaffold for cartilage tissue repair: In-vitro and in-vivo study

    , Article Materials Science and Engineering C ; Volume 128 , 2021 ; 09284931 (ISSN) Haghighi, P ; Shamloo, A ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    Self-repairing is not an advanced ability of articular cartilage. Tissue engineering has provided a novel way for reconstructing cartilage using natural polymers because of their biocompatibility and bio-functionality. The purpose of cartilage tissue engineering is to design a scaffold with proper pore structure and similar biological and mechanical properties to the native tissue. In this study, porous scaffolds prepared from gelatin, chitosan and silk fibroin were blended with varying ratios. Between the blends of chitosan (C), gelatin (G) and silk fibroin (S), the scaffold with the weight per volume ratio of 2:2:3 (w/v) showed the most favorable and higher certain properties than the... 

    Rolled graphene oxide foams as three-dimensional scaffolds for growth of neural fibers using electrical stimulation of stem cells

    , Article Carbon ; Volume 97 , 2016 , Pages 71-77 ; 00086223 (ISSN) Akhavan, O ; Ghaderi, E ; Shirazian, S. A ; Rahighi, R ; Sharif University of Technology
    Elsevier Ltd 
    Abstract
    Graphene oxide foam (GOF) layers with thicknesses of ∼15-50 μm and density of ∼10 graphene oxide (GO) sheets/μm were fabricated by precipitation of chemically exfoliated GO sheets in an aqueous suspension at ∼80 °C under UV irradiation. Then, rolled GOFs with desirable scales were developed as electrically conductive 3D-scaffolds and applied in directional growth of neural fibers, through differentiation of human neural stem cells (hNSCs) into neurons under an electrical stimulation. X-ray photoelectron spectroscopy indicated that the UV irradiation resulted in partial deoxygenation of the layers. Scanning electron microscopy and Raman spectroscopy confirmed the presence of multilayer GO... 

    A hybrid scaffold of gelatin glycosaminoglycan matrix and fibrin as a carrier of human corneal fibroblast cells

    , Article Materials Science and Engineering C ; Volume 118 , 2021 ; 09284931 (ISSN) Hajian Foroushani, Z ; Mahdavi salimi, S ; Abdekhodaie, M. J ; Baradaran Rafii, A ; Tabatabei, M. R ; Mehrvar, M ; Sharif University of Technology
    Elsevier Ltd  2021
    Abstract
    A hybrid scaffold of gelatin-glycosaminoglycan matrix and fibrin (FGG) has been synthesized to improve the mechanical properties, degradation time and cell response of fibrin-like scaffolds. The FGG scaffold was fabricated by optimizing some properties of fibrin-only gel and gelatin-glycosaminoglycan (GG) scaffolds. Mechanical analysis of optimized fibrin-only gel showed the Young module and tensile strength of up to 72 and 121 KPa, respectively. Significantly, the nine-fold increase in the Young modulus and a seven-fold increase in tensile strength was observed when fibrin reinforced with GG scaffold. Additionally, the results demonstrated that the degradation time of fibrin was enhanced... 

    Fabrication of a highly ordered hierarchically designed porous nanocomposite via indirect 3D printing: Mechanical properties and in vitro cell responses

    , Article Materials and Design ; Volume 88 , 2015 , Pages 924-931 ; 02641275 (ISSN) Tamjid, E ; Simchi, A ; Sharif University of Technology
    Elsevier Ltd  2015
    Abstract
    Design and development of biodegradable scaffolds with highly uniform and controlled internal structure that stimulate tissue regeneration are the focus of many studies. The aim of this work is to apply a modified three-dimensional (3D) printing process to fabricate polymer-matrix composites with controlled internal architecture. Computationally-designed plaster molds with various pore sizes in the range of 300-800. μm were prepared by employing 3D printing of a water-based binder. The molds were converted to ε-polycaprolactone (PCL) and PCL/bioactive glass (BG) composite scaffolds by solvent casting and freeze drying methods. Optical and electron microscopy studies revealed that the pore... 

    Influence of Fe3O4 nanoparticles in hydroxyapatite scaffolds on proliferation of primary human fibroblast cells

    , Article Journal of Materials Engineering and Performance ; 2016 , Pages 1-9 ; 10599495 (ISSN) Maleki Ghaleh, H ; Aghaie, E ; Nadernezhad, A ; Zargarzadeh, M ; Khakzad, A ; Shakeri, M. S ; Beygi Khosrowshahi, Y ; Siadati, M. H ; Sharif University of Technology
    Springer New York LLC  2016
    Abstract
    Modern techniques for expanding stem cells play a substantial role in tissue engineering: the raw material that facilitates regeneration of damaged tissues and treats diseases. The environmental conditions and bioprocessing methods are the primary determinants of the rate of cultured stem cell proliferation. Bioceramic scaffolds made of calcium phosphate are effective substrates for optimal cell proliferation. The present study investigates the effects of two bioceramic scaffolds on proliferating cells in culture media. One scaffold was made of hydroxyapatite and the other was a mixture of hydroxyapatite and ferromagnetic material (Fe3O4 nanoparticles). Disk-shaped (10 mm × 2 mm) samples of... 

    Construction of scaffolds composed of acellular cardiac extracellular matrix for myocardial tissue engineering

    , Article Biologicals ; Volume 53 , 2018 , Pages 10-18 ; 10451056 (ISSN) Esmaeili Pourfarhangi, K ; Mashayekhan, S ; Ghanbari Asl, S ; Hajebrahimi, Z ; Sharif University of Technology
    Academic Press  2018
    Abstract
    High rates of mortality and morbidity stemming from cardiovascular diseases unveil extreme limitations in current therapies despite enormous advances in medical and pharmaceutical sciences. Following myocardial infarction (MI), parts of myocardium undergo irreversible remodeling and is substituted by a scar tissue which eventually leads to heart failure (HF). To address this issue, cardiac patches have been utilized to initiate myocardial regeneration. In this study, a porous cardiac patch is fabricated using a mixture of decellularized myocardium extracellular matrix (ECM) and chitosan (CS). Results of rheological measurements, SEM, biodegradation test, and MTT assay showed that the... 

    Bioengineering approaches for corneal regenerative medicine

    , Article Tissue Engineering and Regenerative Medicine ; Volume 17, Issue 5 , July , 2020 , Pages 567-593 Mahdavi, S. S ; Abdekhodaie, M. J ; Mashayekhan, S ; Baradaran Rafii, A ; Djalilian, A. R ; Sharif University of Technology
    Korean Tissue Engineering and Regenerative Medicine Society  2020
    Abstract
    Background:: Since the cornea is responsible for transmitting and focusing light into the eye, injury or pathology affecting any layer of the cornea can cause a detrimental effect on visual acuity. Aging is also a reason for corneal degeneration. Depending on the level of the injury, conservative therapies and donor tissue transplantation are the most common treatments for corneal diseases. Not only is there a lack of donor tissue and risk of infection/rejection, but the inherent ability of corneal cells and layers to regenerate has led to research in regenerative approaches and treatments. Methods:: In this review, we first discussed the anatomy of the cornea and the required properties for... 

    Microfluidic technologies to engineer mesenchymal stem cell aggregates—applications and benefits

    , Article Biophysical Reviews ; Volume 12, Issue 1 , 2020 , Pages 123-133 Salehi, S. S ; Shamloo, A ; Kazemzadeh Hannani, S. K ; Sharif University of Technology
    Springer  2020
    Abstract
    Three-dimensional cell culture and the forming multicellular aggregates are superior over traditional monolayer approaches due to better mimicking of in vivo conditions and hence functions of a tissue. A considerable amount of attention has been devoted to devising efficient methods for the rapid formation of uniform-sized multicellular aggregates. Microfluidic technology describes a platform of techniques comprising microchannels to manipulate the small number of reagents with unique properties and capabilities suitable for biological studies. The focus of this review is to highlight recent studies of using microfluidics, especially droplet-based types for the formation, culture, and... 

    A foreign body response-on-a-chip platform

    , Article Advanced Healthcare Materials ; Volume 8, Issue 4 , 2019 ; 21922640 (ISSN) Sharifi, F ; Htwe, S. S ; Righi, M ; Liu, H ; Pietralunga, A ; Yesil Celiktas, O ; Maharjan, S ; Cha, B. H ; Shin, S. R ; Dokmeci, M. R ; Vrana, N. E ; Ghaemmaghami, A. M ; Khademhosseini, A ; Zhang, Y. S ; Sharif University of Technology
    Wiley-VCH Verlag  2019
    Abstract
    Understanding the foreign body response (FBR) and desiging strategies to modulate such a response represent a grand challenge for implant devices and biomaterials. Here, the development of a microfluidic platform is reported, i.e., the FBR-on-a-chip (FBROC) for modeling the cascade of events during immune cell response to implants. The platform models the native implant microenvironment where the implants are interfaced directly with surrounding tissues, as well as vasculature with circulating immune cells. The study demonstrates that the release of cytokines such as monocyte chemoattractant protein 1 (MCP-1) from the extracellular matrix (ECM)-like hydrogels in the bottom tissue chamber... 

    Chitosan-gelatin sheets as scaffolds for muscle tissue engineering

    , Article Artificial Cells, Nanomedicine and Biotechnology ; Volume 43, Issue 2 , Nov , 2015 , Pages 124-132 ; 21691401 (ISSN) Hajiabbas, M ; Mashayekhan, S ; Nazaripouya, A ; Naji, M ; Hunkeler, D ; Rajabi Zeleti, S ; Sharifiaghdas, F ; Sharif University of Technology
    Informa Healthcare  2015
    Abstract
    Hydrogels made of natural polymers [chitosan (CS) and gelatin (G)] have been prepared having mechanical properties similar to those of muscle tissues. In this study, the effect of polymer concentration and scaffold stiffness on the behavior of seeded muscle-derived cells (MDCs) on the CS-G hydrogel sheets has been evaluated. Both variables were found to be important in cell viability. Viability was assessed by observation of the cell morphology after 1 day as well as a 14-day MTT assay. The CS-G hydrogels were characterized using Fourier transform infrared (FTIR) analysis, which revealed evidences of strong intermolecular interactions between CS and G. Hydrogel samples with intermediate... 

    Fabrication and characterization of conductive chitosan/gelatin-based scaffolds for nerve tissue engineering

    , Article International Journal of Biological Macromolecules ; Volume 74 , 2015 , Pages 360-366 ; 01418130 (ISSN) Baniasadi, H ; Ramazani S. A., A ; Mashayekhan, S ; Sharif University of Technology
    Abstract
    This paper reports on the development of conductive porous scaffolds by incorporating conductive polyaniline/graphene (PAG) nanoparticles into a chitosan/gelatin matrix for its potential application in peripheral nerve regeneration. The effect of PAG content on the various properties of the scaffold is investigated and the results showed that the electrical conductivity and mechanical properties increased proportional to the increase in the PAG loading, while the porosity, swelling ratio and in vitro biodegradability decreased. In addition, the biocompatibility was evaluated by assessing the adhesion and proliferation of Schwann cells on the prepared scaffolds using SEM and MTT assay,... 

    Simulation of the effects of oxygen carriers and scaffold geometry on oxygen distribution and cell growth in a channeled scaffold for engineering myocardium

    , Article Mathematical Biosciences ; Volume 294 , 2017 , Pages 160-171 ; 00255564 (ISSN) Zehi Mofrad, A ; Mashayekhan, S ; Bastani, D ; Sharif University of Technology
    Abstract
    This study proposes a mathematical model to evaluate the impact of oxygen carriers and scaffold geometry on oxygen distribution and cell growth in a 3D cardiac construct using computational fluid dynamics (CFD). Flow equations, oxygen balance equation and cell balance equation were solved using special initial and boundary conditions. The modeling results revealed that 55% increase in cardiac cell density occurred by using 6.4% perfluorocarbon oxygen carrier (PFC) compared to pure culture medium without PFC supplementation. Moreover, the effects of the scaffold geometry on cell density were examined by changing the channel numbers and the construct length. A 30% increase in the average cells... 

    Fabrication and characterization of core-shell electrospun fibrous mats containing medicinal herbs for wound healing and skin tissue engineering

    , Article Marine Drugs ; Volume 17, Issue 1 , 2019 ; 16603397 (ISSN) Zahedi, E ; Esmaeili, A ; Eslahi, N ; Shokrgozar, M. A ; Simchi, A ; Sharif University of Technology
    MDPI AG  2019
    Abstract
    Nanofibrous structures mimicking the native extracellular matrix have attracted considerable attention for biomedical applications. The present study aims to design and produce drug-eluting core-shell fibrous scaffolds for wound healing and skin tissue engineering. Aloe vera extracts were encapsulated inside polymer fibers containing chitosan, polycaprolactone, and keratin using the co-axial electrospinning technique. Electron microscopic studies show that continuous and uniform fibers with an average diameter of 209 ± 47 nm were successfully fabricated. The fibers have a core-shell structure with a shell thickness of about 90 nm, as confirmed by transmission electron microscopy. By... 

    Extraction of hydroxyapatite nanostructures from marine wastes for the fabrication of biopolymer-based porous scaffolds

    , Article Marine Drugs ; Volume 18, Issue 1 , 2020 Gheysari, H ; Mohandes, F ; Mazaheri, M ; Dolatyar, B ; Askari, M ; Simchi, A ; Sharif University of Technology
    MDPI AG  2020
    Abstract
    Three-dimensional porous nanocomposites consisting of gelatin-carboxymethylcellulose (CMC) cross-linked by carboxylic acids biopolymers and monophasic hydroxyapatite (HA) nanostructures were fabricated by lyophilization, for soft-bone-tissue engineering. The bioactive ceramic nanostructures were prepared by a novel wet-chemical and low-temperature procedure from marine wastes containing calcium carbonates. The effect of surface-active molecules, including sodium dodecyl sulfate (SDS) and hexadecyltrimethylammonium bromide (CTAB), on the morphology of HA nanostructures is shown. It is demonstrated that highly bioactive and monophasic HA nanorods with an aspect ratio > 10 can be synthesized in... 

    Stereolithography 3D bioprinting method for fabrication of human corneal stroma equivalent

    , Article Annals of Biomedical Engineering ; Volume 48, Issue 7 , June , 2020 , Pages 1955-1970 Mahdavi, S. S ; Abdekhodaie, M. J ; Kumar, H ; Mashayekhan, S ; Baradaran Rafii, A ; Kim, K ; Sharif University of Technology
    Springer  2020
    Abstract
    Abstract: 3D bioprinting technology is a promising approach for corneal stromal tissue regeneration. In this study, gelatin methacrylate (GelMA) mixed with corneal stromal cells was used as a bioink. The visible light-based stereolithography (SLA) 3D bioprinting method was utilized to print the anatomically similar dome-shaped structure of the human corneal stroma. Two different concentrations of GelMA macromer (7.5 and 12.5%) were tested for corneal stroma bioprinting. Due to high macromer concentrations, 12.5% GelMA was stiffer than 7.5% GelMA, which made it easier to handle. In terms of water content and optical transmittance of the bioprinted scaffolds, we observed that scaffold with... 

    Fabrication and characterization of scaffolds containing different amounts of allantoin for skin tissue engineering

    , Article Scientific Reports ; Volume 11, Issue 1 , 2021 ; 20452322 (ISSN) Dorri Nokoorani, Y ; Shamloo, A ; Bahadoran, M ; Moravvej, H ; Sharif University of Technology
    Nature Research  2021
    Abstract
    Using the skin tissue engineering approach is a way to help the body to recover its lost skin in cases that the spontaneous healing process is either impossible or inadequate, such as severe wounds or burns. In the present study, chitosan/gelatin-based scaffolds containing 0.25, 0.5, 0.75, and 1% allantoin were created to improve the wounds’ healing process. EDC and NHS were used to cross-link the samples, which were further freeze-dried. Different in-vitro methods were utilized to characterize the specimens, including SEM imaging, PBS absorption and degradation tests, mechanical experiments, allantoin release profile assessment, antibacterial assay, and cell viability and adhesion tests.... 

    Comparison of engineered cartilage based on BMSCs and chondrocytes seeded on PVA-PPU scaffold in a sheep model

    , Article Journal of Biomedical Materials Research - Part B Applied Biomaterials ; Volume 110, Issue 11 , 2022 , Pages 2411-2421 ; 15524973 (ISSN) Taghizadehjahed, M ; Sepahdar, A ; Rabiee, N ; Nazbar, A ; Farzad Mohajeri, S ; Dehghan, M. M ; Shokrgozar, M. A ; Majidi, M ; Mardjanmehr, S. H ; Aminianfar, H ; Akbari Javar, H ; Bonakdar, S ; Sharif University of Technology
    John Wiley and Sons Inc  2022
    Abstract
    In this study, polyvinyl alcohol hydrogel chains were crosslinked by polyurethane in order to synthesize a suitable substrate for cartilage lesions. The substrate was fully characterized, and in vitro and in vivo investigations were conducted based on a sheep model. In vitro tests were performed based on the chondrocyte cells with the Alcian Blue and safranin O staining in order to prove the presence of proteoglycan on the surface of the synthesized substrate, which has been secreted by cultures of chondrocytes. Furthermore, the expression of collagen type I, collagen type II, aggrecan, and Sox9 was presented in the chondrocyte cultures on the synthesized substrate through RT-PCR. In... 

    Polymer/metal composite 3D porous bone tissue engineering scaffolds fabricated by additive manufacturing techniques: A review

    , Article Bioprinting ; Volume 25 , 2022 ; 24058866 (ISSN) Mohammadi Zerankeshi, M ; Bakhshi, R ; Alizadeh, R ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    The employment of tissue engineering scaffolds in the reconstruction of the damaged bone tissues has shown remarkable promise since they significantly facilitate the healing process. Fabrication of highly porous biocompatible scaffolds with sufficient mechanical strength is still challenging. In this regard, polymers have been widely utilized to construct three-dimensional (3D) porous scaffolds due to their excellent processability and biocompatibility. However, insufficient mechanical strength and inappropriate degradation rate of the monophasic polymer scaffolds in the bone regeneration process, as the main challenges, limit their extensive clinical application. The incorporation of...