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Hybrid silk fibroin–gelatin nanofibrous sheet for drug delivery and regenerative medicine: In-vitro characterization and controlled release of simvastatin/protein
, Article Polymers for Advanced Technologies ; 2020 ; Alemzadeh, I ; Vossoughi, M ; Sharif University of Technology
John Wiley and Sons Ltd
2020
Abstract
Blend drug-loading method in electrospun scaffolds has gained much attention as a cost-effective and simple delivery system in regenerative medicine. However, it has some drawbacks, such as the burst release of encapsulated drugs and denaturing active agents in harsh organic solvents. In this study, a new silk fibroin-gelatin (SF–G) fibrous sheet has been introduced as an engineered scaffold and a straightforward drug delivery system for skin tissue engineering applications. The hybrid sheets have been prepared via co-electrospinning and in-situ crosslinking methods without corrosive solvents and toxic crosslinking agents. To evaluate the proposed scaffold as a controlled release system, the...
A porous hydrogel-electrospun composite scaffold made of oxidized alginate/gelatin/silk fibroin for tissue engineering application
, Article Carbohydrate Polymers ; Volume 245 , 2020 ; Alemzadeh, I ; Vossoughi, M ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In the article, a bilayer nanocomposite scaffold made of oxidized alginate (OAL), gelatin (G), and silk fibroin (SF) has been prepared via combining electrospinning, in situ gas foaming, in situ crosslinking and freeze drying methods. The physicochemical and mechanical properties, as well as thermal stability of the proposed composite, have been investigated by SEM, FTIR, XRD, tensile, and TGA analysis. The data indicate that structure and degree of crosslinking play a vital role in adjusting the physical and mechanical properties of composite scaffolds. Further, the authors find a favorable adipose-derived mesenchymal stem cell's (AMSC) attachment and distribution within this novel...
Hybrid silk fibroin–gelatin nanofibrous sheet for drug delivery and regenerative medicine: In-vitro characterization and controlled release of simvastatin/protein
, Article Polymers for Advanced Technologies ; Volume 32, Issue 3 , 2021 , Pages 1333-1344 ; 10427147 (ISSN) ; Alemzadeh, I ; Vossoughi, M ; Sharif University of Technology
John Wiley and Sons Ltd
2021
Abstract
Blend drug-loading method in electrospun scaffolds has gained much attention as a cost-effective and simple delivery system in regenerative medicine. However, it has some drawbacks, such as the burst release of encapsulated drugs and denaturing active agents in harsh organic solvents. In this study, a new silk fibroin-gelatin (SF–G) fibrous sheet has been introduced as an engineered scaffold and a straightforward drug delivery system for skin tissue engineering applications. The hybrid sheets have been prepared via co-electrospinning and in-situ crosslinking methods without corrosive solvents and toxic crosslinking agents. To evaluate the proposed scaffold as a controlled release system, the...
In-situ crosslinking of electrospun gelatin-carbodiimide nanofibers: fabrication, characterization, and modeling of solution parameters
, Article Chemical Engineering Communications ; 2020 ; Alemzadeh, I ; Vossoughi, M ; Shamloo, A ; Sharif University of Technology
Taylor and Francis Ltd
2020
Abstract
This work has focused on in-situ crosslinking of gelatin (G) to produce electrospun scaffold with improved fiber morphology retention and mechanical properties. As per this approach, we prepared G nanofibers through mixing G, 1-ethyl-3-(3 dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) in the new solvent system. Response surface methodology (RSM) was employed to study the influence of solution parameters on fiber diameter. The morphological structure was examined, and the appropriate level of setting to obtain smooth fibers with a favorable diameter was reported. Results revealed using EDC/NHS for in-situ crosslinking improves the mechanical properties...
In-situ crosslinking of electrospun gelatin-carbodiimide nanofibers: fabrication, characterization, and modeling of solution parameters
, Article Chemical Engineering Communications ; Volume 208, Issue 7 , 2021 , Pages 976-992 ; 00986445 (ISSN) ; Alemzadeh, I ; Vossoughi, M ; Shamloo, A ; Sharif University of Technology
Taylor and Francis Ltd
2021
Abstract
This work has focused on in-situ crosslinking of gelatin (G) to produce electrospun scaffold with improved fiber morphology retention and mechanical properties. As per this approach, we prepared G nanofibers through mixing G, 1-ethyl-3-(3 dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) in the new solvent system. Response surface methodology (RSM) was employed to study the influence of solution parameters on fiber diameter. The morphological structure was examined, and the appropriate level of setting to obtain smooth fibers with a favorable diameter was reported. Results revealed using EDC/NHS for in-situ crosslinking improves the mechanical properties...
Investigating the Optimum Conditions for Cell Growth and Behavior on Hydrogel Surfaces
, M.Sc. Thesis Sharif University of Technology ; Mashayekhan, Shohre (Supervisor) ; Maghsudi, Vida (Supervisor)
Abstract
Generally, the concept of producing ‘spare parts’ of the body for replacement of damaged or lost organs lies at the core of the varied biotechnological practices referred as tissue engineering. Tissue engineering is an interdisciplinary field that incorporates principles of engineering with the life sciences. Tissue engineering is based on three principle; cells, scaffolds for cells expansion, attachment as an environment like ECM and growth factors. These things together can help tissue engineers to provide microenvironments which are suitable for special cells. The most important thing in this kind of works is the ability to simulate environment for cells the same as body. According to the...
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) ; 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...
Study and Fabrication of a Multilayer Scaffold Containing Biological Agents for Skin Wounds Regeneration
, Ph.D. Dissertation Sharif University of Technology ; Alemzadeh, Iran (Supervisor) ; Vossoughi, Manouchehr (Supervisor) ; Shamloo, Amir (Co-Supervisor)
Abstract
In recent years, it is expected that the fabrication of multilayer scaffolds and the use of different methodologies in one product can be a new progressing method in skin substitute production. Accordingly, this project aims to fabricate a bilayered composite scaffold with a combination of hydrogel and electrospinning method. We have tried to prepare a scaffold made of oxidized alginate (OAL), gelatin (G), and silk fibroin (SF) without using corrosive solvents and toxic crosslinking agents as a scaffold and drug delivery system. As different biological, chemical, physical, and mechanical factors play a vital role in the healing process, we have characterized the proposed scaffold via DSC,...
Probability of missed detection as a criterion for receiver placement in MIMO PCL
, Article IEEE National Radar Conference - Proceedings, 7 May 2012 through 11 May 2012, Atlanta, GA ; 2012 , Pages 0924-0927 ; 10975659 (ISSN) ; 9781467306584 (ISBN) ; Chitgarha, M. M ; Radmard, M ; Nayebi, M. M ; Sharif University of Technology
IEEE
2012
Abstract
Using multiple antennas at the transmit and receive sides of a passive radar brings both the benefits of MIMO radar and passive radar. However one of the obstacles arisen in such configuration is the receive antennas placement in proper positions so that the radar performance is improved. Here we just consider the case of positioning one receiver among multiple illuminators of opportunity. Indeed it is a start for the solution of optimizing the geometry of the multiple receivers in a passive radar
An efficient method for the ring opening of epoxides with aromatic amines by Sb(III) chloride under microwave irradiation
, Article Journal of Chemical Research ; Issue 4 , 2008 , Pages 220-221 ; 03082342 (ISSN) ; Hashemi, M. M ; Mottaghi, M. M ; Foroughi, M. M ; Sharif University of Technology
2008
Abstract
SbCl3 supported on montmorillonite K-10 is an efficient catalyst for the ring opening of epoxides with aromatic amines under solvent-free conditions and microwave irradiation to give the corresponding b-amino alcohols in high yields with high regioselectivity
Resource allocation for uav-enabled integrated sensing and communication (isac) via multi-objective optimization
, Article ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings ; Volume 2023-June , 2023 ; 15206149 (ISSN); 978-172816327-7 (ISBN) ; Naghsh, M. M ; Karbasi, M ; Nayebi, M. M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2023
Abstract
In this paper, we consider an integrated sensing and communication (ISAC) system with wireless power transfer (WPT) where an unmanned aerial vehicle (UAV)-based radar serves a group of energy-limited communication users in addition to its sensing functionality. In this architecture, the radar senses the environment in phase 1 (namely sensing phase) and mean-while, the communications users (nodes) harvest and store the energy from the radar transmit signal. The stored energy is then used for information transmission from the nodes to UAV in phase 2, i.e., uplink phase. Performance of the radar system depends on the transmit signal as well as the receive filter; the energy of the transmit...
MIMO radar signal design to improve the MIMO ambiguity function via maximizing its peak
, Article Signal Processing ; Volume 118 , 2016 , Pages 139-152 ; 01651684 (ISSN) ; Radmard, M ; Nazari Majd, M ; Karbasi, S. M ; Nayebi, M. M ; Sharif University of Technology
Elsevier
2016
Abstract
One of the important obstacles in MIMO (Multiple Input Multiple Output) radars is the issue of designing proper transmit signals. Indeed, the capability of signal design is a significant advantage in MIMO radars, through which, the system can achieve much better performance. Many different aspects of this performance improvement have been considered yet, and the transmit signals have been designed to attain such goal, e.g., getting higher SNR or better detector's performance at the receiver. However, an important tool for evaluating the radar's performance is its ambiguity function. In this paper, we consider the problem of transmit signal design, in order to optimize the ambiguity function...
Detection-localization tradeoff in MIMO radars
, Article Radioengineering ; Volume 26, Issue 2 , 2017 , Pages 581-587 ; 12102512 (ISSN) ; Radmard, M ; Chitgarha, M. M ; Bastani, M. H ; Nayebi, M. M ; Sharif University of Technology
2017
Abstract
Two gains play key roles in recently developed MIMO wireless communication systems: "spatial diversity" gain and "spatial multiplexing" gain. The diversity gain refers to the capability to decrease the error rate of the MIMO channel, while the multiplexing gain implicitly refers to the amount of increase in the capacity of the MIMO channel. It has been shown that there is a fundamental tradeoff between these two types of gains, meaning interplay between increasing reliability (via an increase in the diversity gain) and increasing data rate (via an increase in the multiplexing gain). On the other hand, recently, MIMO radars have attracted much attention for their superior ability to enhance...
Antenna placement and power allocation optimization in MIMO detection
, Article IEEE Transactions on Aerospace and Electronic Systems ; Vol. 50, Issue 2 , April , 2014 , pp. 1468-1478 ; Chitgarha, M. M ; Majd, M. N ; Nayebi, M. M ; Sharif University of Technology
2014
Abstract
It is a well known fact that using multiple antennas at transmit and receive sides improves the detection performance. However, in such multiple-input multiple-output (MIMO) configuration, proper positioning of transmitters and receivers is a big challenge that can have significant influence on the performance of the overall system. In addition, determining the power of each transmitter under a total power constraint is a problem that should be solved in order to enhance the performance and coverage of such a system. In this paper, we design the Neyman-Pearson detector under the Rayleigh scatter model and use it to introduce a criterion for the antenna placement at both transmit and receive...
Ambiguity function of MIMO radar with widely separated antennas
, Article Proceedings International Radar Symposium ; 16 -18 June , 2014 ; ISSN: 21555753 ; Chitgarha, M. M ; Nazari Majd, M ; Nayebi, M. M ; Sharif University of Technology
2014
Abstract
There has been much interest, recently, towards exploiting the Multiple-Input Multiple-Output (MIMO) technique in radar. It is shown that using multiple antennas at transmit and receive sides can improve the performance of the system. However, in order to analyze the system's performance, its ambiguity function, i.e. the ambiguity function of a MIMO radar, is needed to be defined. In this paper, beginning from the information theoretic definitions, we derive such function, specifically for a MIMO radar with widely separated antennas
Choosing the position of the receiver in a MISO passive radar system
, Article European Microwave Week 2012: "Space for Microwaves", EuMW 2012, Conference Proceedings - 9th European Radar Conference, EuRAD 2012 ; 2012 , Pages 318-321 ; 9782874870293 (ISBN) ; Majd, M. N ; Radmard, M ; Nayebi, M. M ; Sharif University of Technology
2012
Abstract
By combining the two ideas of MIMO (Multiple Input Multiple Output) and PCL (Passive Coherent Location) in radar, one can achieve the advantages of both recently developed techniques simultaneously. While using multiple antennas at the receive side provides a spatial diversity of the object to be detected, using multiple illuminators of opportunity, most importantly, makes the radar covert to the interceptors. One obstacle in such MIMO configuration is choosing the positions of the receive antennas. In this paper, after analyzing the Neyman-Pearson detector for the DVB-T based PCL, we introduce the probability of missed detection as a criterion to place the receive antenna. Here, we only...
Adaptive filtering techniques in passive radar
, Article Proceedings International Radar Symposium, Dresden ; Volume 2 , June , 2013 , Pages 1067-1078 ; 21555753 (ISSN) ; 9783954042234 (ISBN) ; Radmard, M ; Majd, M. N ; Nayebi, M. M ; Sharif University of Technology
2013
Abstract
One of the most important obstacles in passive radar applications is removing the direct signal from the target channel. Otherwise, week echoes from the targets in the target channel would be ignored due to the limited dynamic range of the system. One of the most effective techniques in this field is using adaptive filters. In this paper various adaptive filters are introduced and their performances are shown and compared
Ambiguity function based receiver placement in multi-site radar
, Article 2016 CIE International Conference on Radar, RADAR 2016, 10 October 2016 through 13 October 2016 ; 2017 ; 9781509048281 (ISBN) ; Chitgarha, M. M ; Nazari Majd, M ; Nayebi, M. M ; Sharif University of Technology
2017
Abstract
It has been shown that using multiple antennas in a radar system improves the performance considerably, since multiple target echoes are received from different aspect angles of the target. In this way, the target detection is improved. However, when using multiple antennas, some problems, such as designing the transmit signals, synchronization, etc. emerge that should be solved. One of such problems is the receiver placement. Receiver placement deals with choosing a proper position for the receive antenna in order to optimize the whole system's performance. In this paper, a receiver placement procedure based on improving the radar ambiguity function is proposed for the case of a multisite...
Improving MIMO radar's performance through receivers' positioning
, Article IET Signal Processing ; Volume 11, Issue 5 , 2017 , Pages 622-630 ; 17519675 (ISSN) ; Radmard, M ; Nazari Majd, M ; Nayebi, M. M ; Sharif University of Technology
Institution of Engineering and Technology
2017
Abstract
By employing the MIMO (multiple-input-multiple-output) technology in radar, some new problems emerged, that, in order to benefit the MIMO gains in radar, it was necessary to solve them suitably. One of such obstacles is determining the positions of receive antennas in a MIMO radar system with widely separated antennas (WS MIMO radar), since it is shown that the antennas' positions affect the whole system's performance considerably. In this study, a proper receivers' positioning procedure is proposed. To do this end, four criteria are developed based on the proposed MIMO detector and the MIMO ambiguity function. The simulations verify that the proposed positioning procedure improves the...
Silylation of hydroxy groups with HMDS under microwave irradiation and solvent-free conditions
, Article Phosphorus, Sulfur and Silicon and Related Elements ; Volume 177, Issue 2 , 2002 , Pages 289-292 ; 10426507 (ISSN) ; Saidi, M. R ; Bolourtchian, M ; Heravi, M. M ; Sharif University of Technology
2002
Abstract
Phenols and alcohols are silylated with hexamethyldisilazane (HMDS) under microwave irradiation in solvent-free condition in good to excellent yields