Sajjad Rahmani Dabbagh
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Sajjad Rahmani Dabbagh has a total of 37 co-authors. Here are the top co-authors by number of shared publications:
- Savas Tasoglu
Department of Biomedical Sciences and Engineering, Koç University, Sariyer, Istanbul, Turkey 34450
13 shared publications - Ali Kemal Yetisen
Department of Chemical Engineering, Imperial College London, South Kensington, London, SW7 2BU, UK
3 shared publications Ali Kemal Yetisen
Department of Chemical Engineering, Imperial College London 6 , London SW7 2AZ, United Kingdom
2 shared publications- Berin Ozdalgic
Istanbul Univ, Grad Sch Engn & Sci, TR-34452 Istanbul, Turkey
2 shared publications - Merve Ustun
Graduate School of Sciences and Engineering, Koc University, Sariyer, 34450 Istanbul, Turkey
2 shared publications Oguzhan Ozcan
Koç University Arçelik Research Center for Creative Industries (KUAR) , Koç University , Sariyer , 34450 Istanbul , Turkey
2 shared publications
Latest Publications
- 13 January 2023
- Published by Springer Nature in Archives of Gynecology and Obstetrics
- Vol. 308 (6) , 1679-1690
Additive manufacturing and three-dimensional printing in obstetrics and gynecology: a comprehensive review
Three-dimensional (3D) printing, also known as additive manufacturing, is a technology used to create complex 3D structures out of a digital model that can be almost any shape. Additive manufacturing allows the creation of customized, finely detailed constructs. Improvements in 3D printing, increased 3D printer availability, decreasing costs, development of biomaterials, and improved cell culture techniques have enabled complex, novel, and customized medical applications to develop. There have been rapid development and utilization of 3D printing technologies in orthopedics, dentistry, urology, reconstructive surgery, and other health care areas. Obstetrics and Gynecology (OBGYN) is an emerging application field for 3D printing. This technology can be utilized in OBGYN for preventive medicine, early diagnosis, and timely treatment of women-and-fetus-specific health issues. Moreover, 3D printed simulations of surgical procedures enable the training of physicians according to the needs of any given procedure. Herein, we summarize the technology and materials behind additive manufacturing and review the most recent advancements in the application of 3D printing in OBGYN studies, such as diagnosis, surgical planning, training, simulation, and customized prosthesis. Furthermore, we aim to give a future perspective on the integration of 3D printing and OBGYN applications and to provide insight into the potential applications.
- 13 January 2023
- Published by Springer Nature in Archives of Gynecology and Obstetrics
- Vol. 308 (6) , 1679-1690
Additive manufacturing and three-dimensional printing in obstetrics and gynecology: a comprehensive review
Three-dimensional (3D) printing, also known as additive manufacturing, is a technology used to create complex 3D structures out of a digital model that can be almost any shape. Additive manufacturing allows the creation of customized, finely detailed constructs. Improvements in 3D printing, increased 3D printer availability, decreasing costs, development of biomaterials, and improved cell culture techniques have enabled complex, novel, and customized medical applications to develop. There have been rapid development and utilization of 3D printing technologies in orthopedics, dentistry, urology, reconstructive surgery, and other health care areas. Obstetrics and Gynecology (OBGYN) is an emerging application field for 3D printing. This technology can be utilized in OBGYN for preventive medicine, early diagnosis, and timely treatment of women-and-fetus-specific health issues. Moreover, 3D printed simulations of surgical procedures enable the training of physicians according to the needs of any given procedure. Herein, we summarize the technology and materials behind additive manufacturing and review the most recent advancements in the application of 3D printing in OBGYN studies, such as diagnosis, surgical planning, training, simulation, and customized prosthesis. Furthermore, we aim to give a future perspective on the integration of 3D printing and OBGYN applications and to provide insight into the potential applications.
- Open Access
- 7 November 2022
- Published by MDPI AG in Journal of Functional Biomaterials
- Vol. 13 (4) , 225
Shape Fidelity Evaluation of Alginate-Based Hydrogels through Extrusion-Based Bioprinting
Extrusion-based 3D bioprinting is a promising technique for fabricating multi-layered, complex biostructures, as it enables multi-material dispersion of bioinks with a straightforward procedure (particularly for users with limited additive manufacturing skills). Nonetheless, this method faces challenges in retaining the shape fidelity of the 3D-bioprinted structure, i.e., the collapse of filament (bioink) due to gravity and/or spreading of the bioink owing to the low viscosity, ultimately complicating the fabrication of multi-layered designs that can maintain the desired pore structure. While low viscosity is required to ensure a continuous flow of material (without clogging), a bioink should be viscous enough to retain its shape post-printing, highlighting the importance of bioink properties optimization. Here, two quantitative analyses are performed to evaluate shape fidelity. First, the filament collapse deformation is evaluated by printing different concentrations of alginate and its crosslinker (calcium chloride) by a co-axial nozzle over a platform to observe the overhanging deformation over time at two different ambient temperatures. In addition, a mathematical model is developed to estimate Young’s modulus and filament collapse over time. Second, the printability of alginate is improved by optimizing gelatin concentrations and analyzing the pore size area. In addition, the biocompatibility of proposed bioinks is evaluated with a cell viability test. The proposed bioink (3% w/v gelatin in 4% alginate) yielded a 98% normalized pore number (high shape fidelity) while maintaining >90% cell viability five days after being bioprinted. Integration of quantitative analysis/simulations and 3D printing facilitate the determination of the optimum composition and concentration of different elements of a bioink to prevent filament collapse or bioink spreading (post-printing), ultimately resulting in high shape fidelity (i.e., retaining the shape) and printing quality.
- 7 November 2022
- Published by MDPI AG in Journal of Functional Biomaterials
- Vol. 13 (4) , 225
Open AccessShape Fidelity Evaluation of Alginate-Based Hydrogels through Extrusion-Based Bioprinting
Extrusion-based 3D bioprinting is a promising technique for fabricating multi-layered, complex biostructures, as it enables multi-material dispersion of bioinks with a straightforward procedure (particularly for users with limited additive manufacturing skills). Nonetheless, this method faces challenges in retaining the shape fidelity of the 3D-bioprinted structure, i.e., the collapse of filament (bioink) due to gravity and/or spreading of the bioink owing to the low viscosity, ultimately complicating the fabrication of multi-layered designs that can maintain the desired pore structure. While low viscosity is required to ensure a continuous flow of material (without clogging), a bioink should be viscous enough to retain its shape post-printing, highlighting the importance of bioink properties optimization. Here, two quantitative analyses are performed to evaluate shape fidelity. First, the filament collapse deformation is evaluated by printing different concentrations of alginate and its crosslinker (calcium chloride) by a co-axial nozzle over a platform to observe the overhanging deformation over time at two different ambient temperatures. In addition, a mathematical model is developed to estimate Young’s modulus and filament collapse over time. Second, the printability of alginate is improved by optimizing gelatin concentrations and analyzing the pore size area. In addition, the biocompatibility of proposed bioinks is evaluated with a cell viability test. The proposed bioink (3% w/v gelatin in 4% alginate) yielded a 98% normalized pore number (high shape fidelity) while maintaining >90% cell viability five days after being bioprinted. Integration of quantitative analysis/simulations and 3D printing facilitate the determination of the optimum composition and concentration of different elements of a bioink to prevent filament collapse or bioink spreading (post-printing), ultimately resulting in high shape fidelity (i.e., retaining the shape) and printing quality.
- Open Access
- 16 May 2022
- Published by MDPI AG in Applied Sciences
- Vol. 12 (10) , 5029
Three-Dimensional-Bioprinted Liver Chips and Challenges
Drug testing, either on animals or on 2D cell cultures, has its limitations due to inaccurate mimicking of human pathophysiology. The liver, as one of the key organs that filters and detoxifies the blood, is susceptible to drug-induced injuries. Integrating 3D bioprinting with microfluidic chips to fabricate organ-on-chip platforms for 3D liver cell cultures with continuous perfusion can offer a more physiologically relevant liver-mimetic platform for screening drugs and studying liver function. The development of organ-on-chip platforms may ultimately contribute to personalized medicine as well as body-on-chip technology that can test drug responses and organ–organ interactions on a single or linked chip model.
- 16 May 2022
- Published by MDPI AG in Applied Sciences
- Vol. 12 (10) , 5029
Open AccessThree-Dimensional-Bioprinted Liver Chips and Challenges
Drug testing, either on animals or on 2D cell cultures, has its limitations due to inaccurate mimicking of human pathophysiology. The liver, as one of the key organs that filters and detoxifies the blood, is susceptible to drug-induced injuries. Integrating 3D bioprinting with microfluidic chips to fabricate organ-on-chip platforms for 3D liver cell cultures with continuous perfusion can offer a more physiologically relevant liver-mimetic platform for screening drugs and studying liver function. The development of organ-on-chip platforms may ultimately contribute to personalized medicine as well as body-on-chip technology that can test drug responses and organ–organ interactions on a single or linked chip model.
- Open Access
3D bioprinted organ‐on‐chips
Organ‐on‐a‐chip (OOC) platforms recapitulate human in vivo‐like conditions more realistically compared to many animal models and conventional two‐dimensional cell cultures. OOC setups benefit from continuous perfusion of cell cultures through microfluidic channels, which promotes cell viability and activities. Moreover, microfluidic chips allow the integration of biosensors for real‐time monitoring and analysis of cell interactions and responses to administered drugs. Three‐dimensional (3D) bioprinting enables the fabrication of multicell OOC platforms with sophisticated 3D structures that more closely mimic human tissues. 3D‐bioprinted OOC platforms are promising tools for understanding the functions of organs, disruptive influences of diseases on organ functionality, and screening the efficacy as well as toxicity of drugs on organs. Here, common 3D bioprinting techniques, advantages, and limitations of each method are reviewed. Additionally, recent advances, applications, and potentials of 3D‐bioprinted OOC platforms for emulating various human organs are presented. Last, current challenges and future perspectives of OOC platforms are discussed.
Open Access3D bioprinted organ‐on‐chips
Organ‐on‐a‐chip (OOC) platforms recapitulate human in vivo‐like conditions more realistically compared to many animal models and conventional two‐dimensional cell cultures. OOC setups benefit from continuous perfusion of cell cultures through microfluidic channels, which promotes cell viability and activities. Moreover, microfluidic chips allow the integration of biosensors for real‐time monitoring and analysis of cell interactions and responses to administered drugs. Three‐dimensional (3D) bioprinting enables the fabrication of multicell OOC platforms with sophisticated 3D structures that more closely mimic human tissues. 3D‐bioprinted OOC platforms are promising tools for understanding the functions of organs, disruptive influences of diseases on organ functionality, and screening the efficacy as well as toxicity of drugs on organs. Here, common 3D bioprinting techniques, advantages, and limitations of each method are reviewed. Additionally, recent advances, applications, and potentials of 3D‐bioprinted OOC platforms for emulating various human organs are presented. Last, current challenges and future perspectives of OOC platforms are discussed.
- Open Access
- 6 February 2022
- Published by MDPI AG in Micromachines
- Vol. 13 (2) , 260
Deep Learning-Enabled Technologies for Bioimage Analysis
Deep learning (DL) is a subfield of machine learning (ML), which has recently demonstrated its potency to significantly improve the quantification and classification workflows in biomedical and clinical applications. Among the end applications profoundly benefitting from DL, cellular morphology quantification is one of the pioneers. Here, we first briefly explain fundamental concepts in DL and then we review some of the emerging DL-enabled applications in cell morphology quantification in the fields of embryology, point-of-care ovulation testing, as a predictive tool for fetal heart pregnancy, cancer diagnostics via classification of cancer histology images, autosomal polycystic kidney disease, and chronic kidney diseases.
- 6 February 2022
- Published by MDPI AG in Micromachines
- Vol. 13 (2) , 260
Open AccessDeep Learning-Enabled Technologies for Bioimage Analysis
Deep learning (DL) is a subfield of machine learning (ML), which has recently demonstrated its potency to significantly improve the quantification and classification workflows in biomedical and clinical applications. Among the end applications profoundly benefitting from DL, cellular morphology quantification is one of the pioneers. Here, we first briefly explain fundamental concepts in DL and then we review some of the emerging DL-enabled applications in cell morphology quantification in the fields of embryology, point-of-care ovulation testing, as a predictive tool for fetal heart pregnancy, cancer diagnostics via classification of cancer histology images, autosomal polycystic kidney disease, and chronic kidney diseases.
- Open Access
- 16 August 2021
- Published by Wiley in Advanced NanoBiomed Research
- Vol. 1 (11) , 2100001
Recent Technological Developments in the Diagnosis and Treatment of Cerebral Edema
Latest technological advancements in neurocritical care have translated to improved clinical outcomes and have paved the way for the effective diagnosis and treatment of cerebral edema. Effective management of cerebral edema has the potential to provide a personalized treatment by obtaining the complete pathophysiological information of the patient. The aims of this review are to inform the reader about the research and development in this field in the past decade as well as the materialization of scientific literature through patents. There is a growing interest in multimodal monitoring of the diseased brain as it provides a necessary means to implement effective intervention strategies. Although there is a gradual shift toward the adoption of noninvasive devices for research purposes, their clinical applications are hindered by their inaccuracies. However, the inherent risk of complication and high costs of implementation challenge the status quo. The role of neuroprotectants is explored and the combination of neurodiagnostic and neuroprotective approaches is proposed. Finally, the impacts of the current state of global affairs are discussed and it is predicted that the rising number of traumatic brain injury patents will inevitably translate to improvements in technologies to effectively address cerebral edema.
- 16 August 2021
- Published by Wiley in Advanced NanoBiomed Research
- Vol. 1 (11) , 2100001
Open AccessRecent Technological Developments in the Diagnosis and Treatment of Cerebral Edema
Latest technological advancements in neurocritical care have translated to improved clinical outcomes and have paved the way for the effective diagnosis and treatment of cerebral edema. Effective management of cerebral edema has the potential to provide a personalized treatment by obtaining the complete pathophysiological information of the patient. The aims of this review are to inform the reader about the research and development in this field in the past decade as well as the materialization of scientific literature through patents. There is a growing interest in multimodal monitoring of the diseased brain as it provides a necessary means to implement effective intervention strategies. Although there is a gradual shift toward the adoption of noninvasive devices for research purposes, their clinical applications are hindered by their inaccuracies. However, the inherent risk of complication and high costs of implementation challenge the status quo. The role of neuroprotectants is explored and the combination of neurodiagnostic and neuroprotective approaches is proposed. Finally, the impacts of the current state of global affairs are discussed and it is predicted that the rising number of traumatic brain injury patents will inevitably translate to improvements in technologies to effectively address cerebral edema.
- Open Access
- 26 April 2021
- Published by MDPI AG in Micromachines
- Vol. 12 (5) , 490
Glioma-on-a-Chip Models
Glioma, as an aggressive type of cancer, accounts for virtually 80% of malignant brain tumors. Despite advances in therapeutic approaches, the long-term survival of glioma patients is poor (it is usually fatal within 12–14 months). Glioma-on-chip platforms, with continuous perfusion, mimic in vivo metabolic functions of cancer cells for analytical purposes. This offers an unprecedented opportunity for understanding the underlying reasons that arise glioma, determining the most effective radiotherapy approach, testing different drug combinations, and screening conceivable side effects of drugs on other organs. Glioma-on-chip technologies can ultimately enhance the efficacy of treatments, promote the survival rate of patients, and pave a path for personalized medicine. In this perspective paper, we briefly review the latest developments of glioma-on-chip technologies, such as therapy applications, drug screening, and cell behavior studies, and discuss the current challenges as well as future research directions in this field.
- 26 April 2021
- Published by MDPI AG in Micromachines
- Vol. 12 (5) , 490
Open AccessGlioma-on-a-Chip Models
Glioma, as an aggressive type of cancer, accounts for virtually 80% of malignant brain tumors. Despite advances in therapeutic approaches, the long-term survival of glioma patients is poor (it is usually fatal within 12–14 months). Glioma-on-chip platforms, with continuous perfusion, mimic in vivo metabolic functions of cancer cells for analytical purposes. This offers an unprecedented opportunity for understanding the underlying reasons that arise glioma, determining the most effective radiotherapy approach, testing different drug combinations, and screening conceivable side effects of drugs on other organs. Glioma-on-chip technologies can ultimately enhance the efficacy of treatments, promote the survival rate of patients, and pave a path for personalized medicine. In this perspective paper, we briefly review the latest developments of glioma-on-chip technologies, such as therapy applications, drug screening, and cell behavior studies, and discuss the current challenges as well as future research directions in this field.
- 1 April 2021
- Published by Frontiers Media SA in Advanced Optical Technologies
- Vol. 10 (2) , 109-121
Portable magnetic levitation technologies
Magnetic levitation (MagLev) is a density-based method which uses magnets and a paramagnetic medium to suspend multiple objects simultaneously as a result of an equilibrium between gravitational, buoyancy, and magnetic forces acting on the particle. Early MagLev setups were bulky with a need for optical or fluorescence microscopes for imaging, confining portability, and accessibility. Here, we review design criteria and the most recent end-applications of portable smartphone-based and self-contained MagLev setups for density-based sorting and analysis of microparticles. Additionally, we review the most recent end applications of those setups, including disease diagnosis, cell sorting and characterization, protein detection, and point-of-care testing.
- 1 April 2021
- Published by Frontiers Media SA in Advanced Optical Technologies
- Vol. 10 (2) , 109-121
Portable magnetic levitation technologies
Magnetic levitation (MagLev) is a density-based method which uses magnets and a paramagnetic medium to suspend multiple objects simultaneously as a result of an equilibrium between gravitational, buoyancy, and magnetic forces acting on the particle. Early MagLev setups were bulky with a need for optical or fluorescence microscopes for imaging, confining portability, and accessibility. Here, we review design criteria and the most recent end-applications of portable smartphone-based and self-contained MagLev setups for density-based sorting and analysis of microparticles. Additionally, we review the most recent end applications of those setups, including disease diagnosis, cell sorting and characterization, protein detection, and point-of-care testing.
- Open Access
- 12 February 2021
- Published by MDPI AG in Micromachines
- Vol. 12 (2) , 182
Hemp-Based Microfluidics
Hemp is a sustainable, recyclable, and high-yield annual crop that can be used to produce textiles, plastics, composites, concrete, fibers, biofuels, bionutrients, and paper. The integration of microfluidic paper-based analytical devices (µPADs) with hemp paper can improve the environmental friendliness and high-throughputness of µPADs. However, there is a lack of sufficient scientific studies exploring the functionality, pros, and cons of hemp as a substrate for µPADs. Herein, we used a desktop pen plotter and commercial markers to pattern hydrophobic barriers on hemp paper, in a single step, in order to characterize the ability of markers to form water-resistant patterns on hemp. In addition, since a higher resolution results in densely packed, cost-effective devices with a minimized need for costly reagents, we examined the smallest and thinnest water-resistant patterns plottable on hemp-based papers. Furthermore, the wicking speed and distance of fluids with different viscosities on Whatman No. 1 and hemp papers were compared. Additionally, the wettability of hemp and Whatman grade 1 paper was compared by measuring their contact angles. Besides, the effects of various channel sizes, as well as the number of branches, on the wicking distance of the channeled hemp paper was studied. The governing equations for the wicking distance on channels with laser-cut and hydrophobic side boundaries are presented and were evaluated with our experimental data, elucidating the applicability of the modified Washburn equation for modeling the wicking distance of fluids on hemp paper-based microfluidic devices. Finally, we validated hemp paper as a substrate for the detection and analysis of the potassium concentration in artificial urine.
- 12 February 2021
- Published by MDPI AG in Micromachines
- Vol. 12 (2) , 182
Open AccessHemp-Based Microfluidics
Hemp is a sustainable, recyclable, and high-yield annual crop that can be used to produce textiles, plastics, composites, concrete, fibers, biofuels, bionutrients, and paper. The integration of microfluidic paper-based analytical devices (µPADs) with hemp paper can improve the environmental friendliness and high-throughputness of µPADs. However, there is a lack of sufficient scientific studies exploring the functionality, pros, and cons of hemp as a substrate for µPADs. Herein, we used a desktop pen plotter and commercial markers to pattern hydrophobic barriers on hemp paper, in a single step, in order to characterize the ability of markers to form water-resistant patterns on hemp. In addition, since a higher resolution results in densely packed, cost-effective devices with a minimized need for costly reagents, we examined the smallest and thinnest water-resistant patterns plottable on hemp-based papers. Furthermore, the wicking speed and distance of fluids with different viscosities on Whatman No. 1 and hemp papers were compared. Additionally, the wettability of hemp and Whatman grade 1 paper was compared by measuring their contact angles. Besides, the effects of various channel sizes, as well as the number of branches, on the wicking distance of the channeled hemp paper was studied. The governing equations for the wicking distance on channels with laser-cut and hydrophobic side boundaries are presented and were evaluated with our experimental data, elucidating the applicability of the modified Washburn equation for modeling the wicking distance of fluids on hemp paper-based microfluidic devices. Finally, we validated hemp paper as a substrate for the detection and analysis of the potassium concentration in artificial urine.
- 6 January 2021
- Published by Wiley in Biotechnology and Bioengineering
- Vol. 118 (4) , 1716-1734
Microfluidics for microalgal biotechnology
Microalgae have expanded their roles as renewable and sustainable feedstocks for biofuel, smart nutrition, biopharmaceutical, cosmeceutical, biosensing, and space technologies. They accumulate valuable biochemical compounds from protein, carbohydrate, and lipid groups, including pigments and carotenoids. Microalgal biomass, which can be adopted for multivalorization under biorefinery settings, allows not only the production of various biofuels but also other value‐added biotechnological products. However, state‐of‐the‐art technologies are required to optimize yield, quality, and the economical aspects of both upstream and downstream processes. As such, the need to use microfluidic‐based devices for both fundamental research and industrial applications of microalgae, arises due to their microscale sizes and dilute cultures. Microfluidics‐based devices are superior to their competitors through their ability to perform multiple functions such as sorting and analyzing small amounts of samples (nanoliter to picoliter) with higher sensitivities. Here, we review emerging applications of microfluidic technologies on microalgal processes in cell sorting, cultivation, harvesting, and applications in biofuels, biosensing, drug delivery, and nutrition.
- 6 January 2021
- Published by Wiley in Biotechnology and Bioengineering
- Vol. 118 (4) , 1716-1734
Microfluidics for microalgal biotechnology
Microalgae have expanded their roles as renewable and sustainable feedstocks for biofuel, smart nutrition, biopharmaceutical, cosmeceutical, biosensing, and space technologies. They accumulate valuable biochemical compounds from protein, carbohydrate, and lipid groups, including pigments and carotenoids. Microalgal biomass, which can be adopted for multivalorization under biorefinery settings, allows not only the production of various biofuels but also other value‐added biotechnological products. However, state‐of‐the‐art technologies are required to optimize yield, quality, and the economical aspects of both upstream and downstream processes. As such, the need to use microfluidic‐based devices for both fundamental research and industrial applications of microalgae, arises due to their microscale sizes and dilute cultures. Microfluidics‐based devices are superior to their competitors through their ability to perform multiple functions such as sorting and analyzing small amounts of samples (nanoliter to picoliter) with higher sensitivities. Here, we review emerging applications of microfluidic technologies on microalgal processes in cell sorting, cultivation, harvesting, and applications in biofuels, biosensing, drug delivery, and nutrition.