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Journal of Chromatography A (00219673) 1757
Microfluidic lab-on-a-chip technologies are revolutionizing diagnostic processes by enabling High-purity particle separation in heterogeneous mixtures, like blood, crucial for swift and accurate diagnoses, particularly in common diseases like cancer or infections where effective pathogen isolation is required. Passive deterministic lateral displacement (DLD) and active acoustophoresis are prominent microfluidic separation methods, each with distinct advantages and limitations. A hybrid approach, combining both, allows simultaneous utilization of their benefits, and enhances separation efficiency and purity through optimal design. A groundbreaking versatile 3D finite element (FE) model of an innovative-designed hybrid microfluidic device, featuring I-shaped DLD arrays and acoustofluidic module based on tilted-angle standing surface acoustic wave (TaSSAW) with focused interdigital transducers (FIDTs), has been presented, accurately predicting particles' behavior and separation dynamics. Simulations of individual devices were also conducted to optimize hybrid device performance, revealing high-efficiency and high-purity separation of polystyrene particles and bioparticles, including circulating tumor cells (MCF-7 CTCs), RBCs, and Escherichia coli bacteria. In the optimized acoustofluidic device, 15 µm polystyrene particles were separated with 100 % purity and 94 % efficiency, while MCF-7 CTCs were separated with 100 % purity and 98 % efficiency. The optimized DLD device achieved 100 % purity and efficiency for 2 µm and 8 µm polystyrene particles, RBCs, and bacteria. In the hybrid device, due to unpredictable factors, MCF-7 CTCs were isolated with 100 % purity but 40 % efficiency, while RBCs and bacteria maintained 100 % purity and efficiency. The results highlight the potential for further geometrical and fluidic optimizations to improve performance, with the 3D model providing a superior predictive tool compared to 2D models, facilitating cost-effective modeling of complex lab-on-a-chip structures. © 2025 Elsevier B.V.
Microfluidics and Nanofluidics (16134982) 29(8)
Bacterial infections are a leading cause of mortality globally, and the timeliness of diagnosis is crucial for effective treatment. Traditional diagnostic methods, reliant on bacterial cultures, are often slow, leading to delays in treatment and increased mortality rates. To address delayed treatments, the study proposes a hybrid microfluidic device that employs deterministic lateral displacement (DLD) and dielectrophoresis (DEP) for rapid and continuous bacterial separation from blood cells. The research utilized COMSOL Multiphysics 5.6 to design and simulate the device, focusing on the optimization of various parameters such as pillar geometry, electrode geometry, fluid velocity, voltage, and DEP frequency. In order to calculate the separation efficiency, 120 particles along with the fluid were entered into the primary initial and the optimized hybrid device. The initial simulations yielded a separation efficiency of approximately 72% for bacteria and red blood cells (RBCs), and 100% for white blood cells (WBCs). After iterative optimization of the device’s design, including changes to the pillar geometries and electrode geometries and numbers, the separation efficiency for bacteria and RBCs was enhanced to 95%, while the efficiency for WBCs remained at 100%. These findings demonstrate the high efficiency of the designed microfluidic device in separating particles, indicating its potential to significantly reduce the time required for the detection of bacterial infections compared to conventional methods. The study presents a model of a microfluidic device that not only accelerates the diagnosis process but also maintains high separation efficiency, making it a promising tool for rapid point-of-care diagnostics. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.
Hadian, M. ,
Rabbani, M. ,
Shariati, L. ,
Ghasemi, F. ,
Presley, J.F. ,
Sanati, A. Acs Sensors (23793694) 10(2)pp. 857-867
The high rate of cancer worldwide and the heavy costs imposed on governments and humanity have always motivated researchers to develop point-of-care (POC) biosensors for easy diagnosis and monitoring of cancer treatment. Herein, we report on a label-free impedimetric biosensor based on Ti3C2Tx MXene and imprinted ortho-phenylenediamine (o-PD) for the detection of carcinoembryonic antigen (CEA), a biomarker for various cancers surveillance, especially colorectal cancer (CRC). Accordingly, MXene was drop-casted on the surface of a disposable silver electrode to increase the sensitivity and create high-energy nanoareas on the surface, which are usable for protein immobilization and detection. A self-assembled monolayer (SAM) was exploited for oriented CEA immobilization on the MXene-modified electrode. The monomer-protein interaction and successful protein removal were confirmed by molecular docking and atomic force microscopy (AFM) investigations to evaluate the quality of the fabricated molecularly imprinted polymer (MIP). Also, the role of MXene in increasing the electrical field inside the nanoareas was simulated using COMSOL Multiphysics software. A suitable limit of detection (9.41 ng/mL), an appropriate linear range of detection (10 to 100 ng/mL) in human serum, and a short detection time (10 min) resulted from the use of SAM/MIP next to MXene. This biosensor presented outstanding repeatability (97.60%) and reproducibility (98.61%). Moreover, acceptable accuracy (between 93.04 and 116.04%) in clinical serum samples was obtained compared with immunoassay results, indicating the high potential of our biosensor for real sample analysis. This biomimetic and disposable sensor provides a cost-effective method for facile and POC monitoring of cancer patients during treatment. © 2024 American Chemical Society.
Farhadi, N. ,
Soltanizadeh, N. ,
Masaeli, E. ,
Rabbani, M. Journal of Food Science and Technology (Iran) (20088787) 22(159)pp. 301-315
The purpose of this study is to investigate the ability of smart scaffolds of Kappa-carrageenan (Carr) and the combination of Kappa-carrageenan and quince seed mucilage (Carr:Quc) to support C2C12 viability and growth for cultured meat production. Carr and Carr:Quc with a final concentration of 1.5% (v/w) were developed using a 5% potassium chloride solution. The capability of the scaffolds to respond to the pH change of the environment was evaluated, and the viability of C2C12 at normal pH (7.4) and varying pH levels (7.4-5.5) was assessed. The evaluation of swelling changes with varying pH (pH 1-7) showed that for the Carr scaffold, the highest swelling was observed at pH 5, reaching 145%, which showed a significant difference compared to swelling at other pH levels (p < 0.05). The highest swelling for the Carr:Quc scaffold was also observed at pH 5, reaching 428%, with a significant difference compared to swelling at other pH levels (p < 0.05). Moreover, the change in the swelling behavior of the scaffolds was evaluated by changing the pH from 7.4 to 5.5. Carr did not show any swelling change, while Carr:Quc demonstrated a significant change in swelling after exposure to pH 5.5 for 30, 45, 60, 180, and 360 min. On Carr:Quc, C2C12 showed higher viability in normal conditions compared to varying pH levels from 7.4 to 5.5. Furthermore, after culturing on Carr:Quc, C2C12 maintained their viability throughout the culture period for 15 days at pH 7.4 and showed the potential for spheroid formation. The findings of this study could pave the way for the design of scaffolds made of edible biopolymers to facilitate tissue engineering of cultured meat. © 2025 Tarbiat Modares University. All rights reserved.
Rabbani, M. ,
Salehani, A.A. ,
Farnaghi, M. ,
Moshtaghi, M. Journal Of Medical Signals And Sensors (22287477) 14(4)
Fabricating three-dimensional (3D) scaffolds is attractive due to various advantages for tissue engineering, such as cell migration, proliferation, and adhesion. Since cell growth depends on transmitting nutrients and cell residues, naturally vascularized scaffolds are superior for tissue engineering. Vascular passages help the inflow and outflow of liquids, nutrients, and waste disposal from the scaffold and cell growth. Porous scaffolds can be prepared by plant tissue decellularization which allows for the cultivation of various cell lines depending on the intended application. To this end, researchers decellularize plant tissues by specific chemical and physical methods. Researchers use plant parts depending on their needs, for example, decellularizing the leaves, stems, and fruits. Plant tissue scaffolds are advantageous for regenerative medicine, wound healing, and bioprinting. Studies have examined various plants such as vegetables and fruits such as orchid, parsley, spinach, celery, carrot, and apple using various materials and techniques such as sodium dodecyl sulfate, Triton X-100, peracetic acid, deoxyribonuclease, and ribonuclease with varying percentages, as well as mechanical and physical techniques like freeze-thaw cycles. The process of data selection, retrieval, and extraction in this review relied on scholarly journal publications and other relevant papers related to the subject of decellularization, with a specific emphasis on plant-based research. The obtained results indicate that, owing to the cellulosic structure and vascular nature of the decellularized plants and their favorable hydrophilic and biological properties, they have the potential to serve as biological materials and natural scaffolds for the development of 3D-printing inks and scaffolds for tissue engineering. © 2024 Journal of Medical Signals & Sensors.
Ahangar salehani, A. ,
Rabbani, M. ,
Biazar, E. ,
Heidari keshel, S. ,
Pourjabbar, B. Engineering Reports (25778196) 5(2)
The decellularization of plant tissues can be one of the design options of scaffolds in tissue engineering. Chemical detergents such as Triton X-100 and sodium dodecyl sulfate (SDS) in different concentrations were used to decellularize olive leaves as an acellular plant matrix for tissue engineering. The samples were investigated by different analyses such as Hematoxylin and Eosin staining, SEM, tensile strength, swelling, water vapor transmission, and toxicity. The results of staining and toxicity tests showed that the Triton X-100 decellularized samples at a concentration of 0.1% had the best morphology and the lowest toxicity. Mechanical results showed that the elasticity modulus of acellular samples was significantly reduced compared to normal leaf samples. While swelling rate and water vapor transmission in acellular samples compared to the control sample doubled and tripled, respectively. In general, acellular olive leaf can be suggested as a scaffold for tissue engineering applications. © 2022 The Authors. Engineering Reports published by John Wiley & Sons Ltd.
Applied Biochemistry and Biotechnology (02732289) 194(5)pp. 2077-2092
The prevalence of diabetes has increased over the past years. Therefore, developing minimally invasive, user-friendly, and cost-effective glucose biosensors is necessary especially in low-income and developing countries. Cellulose paper–based analytical devices have attracted the attention of many researchers due to affordability, not requiring trained personnel, and complex equipment. This paper describes a microfluidic paper-based analytical device (μPAD) for detecting glucose concentration in tear range with the naked eye. The paper-based biosensor fabricated by laser CO2; and glucose oxidase/horseradish peroxidase (GOx/HRP) enzyme solution coupled with tetramethylbenzidine (TMB) were utilized as reagents. A sample volume of 10 μl was needed for the biosensor operation and the results were observable within 5 min. The color intensity–based and distance-based results were analyzed by ImageJ and Tracker to evaluate the device performance. Distance-based results showed a linear behavior in 0.1–1.2 mM with an R2 = 0.9962 and limit of detection (LOD) of 0.1 mM. The results could be perceived by the naked eye without needing additional equipment or trained personnel in a relatively short time (3–5 min). © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
Applied Bionics and Biomechanics (discontinued) (11762322) 2022
Myocardial infarction is one of the leading causes of death in the developed countries. A majority of myocardial infarctions are caused by the rupture of coronary artery plaques. In order to achieve a better understanding of the effect of the extension of the lipid core into the artery wall on the change of flow field and its effect on plaque vulnerability, we have studied the hemodynamic parameters by utilizing a finite element method and taking into account the fluid-structure interaction (FSI). Four groups of stenosis models with different sizes of lipid core were used in the study. The fully developed pulsatile velocity profile of the right coronary artery was used as the inlet boundary condition, and the pressure pulse was applied as the outlet boundary condition. The non-Newtonian Carreau model was used to simulate the non-Newtonian behavior of blood. Results indicate that the extension of the lipid core into the artery wall influences the flow field; subsequently, creates favorable conditions for additional development of the lipid core which can lead to a higher risk of plaque rupture. © 2022 Morteza Teymoori et al.
Asgari kheirabadi, Z. ,
Rabbani, M. ,
Samiei foroushani, M. Applied Biochemistry and Biotechnology (02732289) 194(8)pp. 3689-3705
In this report, a green, simple, inexpensive, and effective nonenzymatic electrochemical glucose sensor was fabricated using multi-walled carbon nanotubes (MWCNT) decorated with copper (II) oxide nanoparticles (CuO NPs). Basil seed mucilage (BSM) was served as reducing, capping, and stabilizing agents in the synthesis of CuO NPs. The prepared MWCNT/CuO nanocomposite was characterized using Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and electrochemical methods. The FTIR results indicated that the nanocomposite surface was covered by BSM. The FESEM results show that the CuO NPs with an average particle size lower than 10 nm have been well distributed on the walls of the MWCNT. The electrochemical behavior of the nanocomposite was explored by studying the electrocatalytic behavior of the screen-printed carbon electrode (SPCE) modified by the nanocomposite (SPCE-MWCNT/CuO) toward the glucose oxidation. In the optimum conditions, the electrode indicated a wide linear response from 5.0 to 620.0 μM with regression coefficients of 0.992, the sensitivity of 1050 μA mM−1 cm−2, a limit of detection (LOD) of 1.7 μM, and a reproducibility with relative standard deviation (RSD) variations from 3.5 to 11% for three measurements at each point. The obtained results also showed good selectivity to glucose against interfering species such as lactate (LA), L-ascorbic acid (AA), and urea (U) due to the use of the negatively charged BSM in the form of a coating on the nanocomposite surface. The applicability of the sensor was successfully verified by the determination of glucose concentration in artificial tears with a certain amount of glucose. Graphical abstract: [Figure not available: see fulltext.] © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
Sanati, A. ,
Bidram, E. ,
Poursamar, S.A. ,
Rabbani, M. ,
Rafienia m., M. FlatChem (24522627) 36
Recently, developing appropriate printing techniques and conductive inks has received considerable attention in the field of (bio)sensors. Extrusion printing technology is an interesting alternative to conventional screen-printing for making flexible and disposable electronics due to its special features such as, direct printing, easy control of design, and manufacturing processes. Moreover, fabricating highly dispersed and stable graphene inks with appropriate conductivity and printability is always a challenge in (bio)sensors. Here, a water-based chitosan/reduced graphene oxide (CS/rGO) ink was obtained using extrusion printing to make conductive electrodes on paper. CS/GO ratio of 0.2 showed the best stability, electrochemical performance and hydrophilicity (water contact angle of 85° ± 6). The resulting sensor was a simple two-electrode device based on the chronoamperometry technique, representing a good potential for detecting glucose in the linear range of 0.5 to 4 mM and with a limit of detection (LOD) of 0.45 mM (S/N = 3). Furthermore, this non-enzymatic sensor showed proper selectivity against interfering substances, as well as an excellent stability during 28 days (2.9% response fall). Ultimately, the developed conductive ink can be considered as an innovative material with high stability and dispersivity of rGO for the future studies on disposable (bio)sensors and flexible electronics. © 2022 Elsevier B.V.
Journal Of Medical Signals And Sensors (22287477) 11(1)pp. 1-11
Biologic scaffolds composed of extracellular matrix (ECM) are frequently used for clinical purposes of tissue regeneration. Different methods have been developed for this purpose. All methods of decellularization including chemical and physical approaches leave some damage on the ECM; however, the effects of these methods are different which make some of these procedures more proper to maintain ECM structure than other methods. This review is aimed to introduce and compare new physical methods for the decellularization of different tissues and organs in tissue engineering. All recent reports and research that have used at least one physical method in the procedure of decellularization, were included and evaluated in this paper. The advantages and drawbacks of each method were examined and compared considering the effectiveness. This review tried to highlight the prospective potentials and benefits of applying physical methods for decellularization protocols in tissue engineering instead of the current chemical methods. These chemical methods are harsh in nature and were shown to be destructive and harmful to essential substances of ECM and scaffold structure. Therefore, using physical methods as a partial or even a whole protocol could save time, costs, and quality of the final acellular tissue in complicated decellularization procedures. Moreover, regarding the control factor that could be achieved easily with physical methods, optimization of different decellularization protocols would be quite satisfactory. Combined methods take advantage of both chemical and physical approaches. © 2021 Isfahan University of Medical Sciences(IUMS). All rights reserved.
Bio-indicators are nowadays being increasingly used by the food and drug industry to detect the changes in environmental conditions. In this study, a time-temperature indicator (TTI) is fabricated by using an office thermal inkjet printer to print a new custom-made bio-ink for detecting changes in color that occur with time and temperature variation. In lieu of the regular inks, the TTI uses solutions containing Geobacillus stearothermophilus (G. stearothermophilus) and Bacillus atrophaeus (B. atrophaeus) spores, tryptic soy broth, pH indicators, and a combination of polyvinyl alcohol and borax as the gelling agent, to be dispensed from the printer cartridge. Following the printing process, the samples thus obtained are coated with a protective film to avoid moisture loss. The effects of bio-ink gelatinization, pH, color intensity, and print resolution on bacterial printing are determined by varying the level of each parameter. The presence of the protective film on printed bacteria is found not only to lead to the growth and proliferation of bacteria but also to reveal color with sharper contrast. The indicator's initial and final colors are modified by varying the pH levels of the solutions. Increasing color intensity (20%, 40%, 60%, 80%, and 100%) in the software settings is used to induce significant enhancements in the printed bacterial populations, thereby controlling the rate of color change. It is, moreover, observed that changes in print resolution do not have any significant effects on the populations of printed bacterial spores. In general, the TTI's endpoint may be modified so as to suit various pharmaceutical and food applications. © 2020 Elsevier B.V.
In this study, a commercial laser printer was used for the first time to print bacteria on different substrates as bacterial carriers to be used in biosensors. For this purpose, the spores of Geobacillus stearothermophilus and Bacillus atrophaeus were mixed with the printer toner and used as a bio-powder in a conventional laser printer to print on a polypropylene film (PF) or copy paper (CP), transfer paper (TP), and filter paper (FP). Subsequently, the effects of the substrate material, print density, print pattern, and color intensity were investigated on the number of bacteria recovered. It was also found that FP was the best substrate, followed, with a significant difference, by TP, for the maximum number of bacteria recovered. Moreover, a color intensity of 100% was found the most appropriate. However, changing print density and pattern showed differences in their effects on bacterial numbers for the two strains tested albeit the differences were not significant. Based on the results obtained, it may be claimed that laser printers can be effectively used for transferring bacteria to paper substrates and used in fabricating biosensors. Printing capabilities and novel toner bio-powders are exploited to choose the proper number of printed bacteria to adapt the printed substrates for use in manufacturing bacterial biosensors. © 2020 Elsevier B.V.
Journal Of Medical Signals And Sensors (22287477) 9(4)pp. 227-233
Background: Decellularization techniques have been widely used in tissue engineering recently. However, applying these methods which are based on removing cells and maintaining the extracellular matrix (ECM) encountered some difficulties for dense tissues such as articular cartilage. Together with chemical agents, using physical methods is suggested to help decellularization of tissues. Methods: In this study, to improve decellularization of articular cartilage, the effects of direct and indirect ultrasonic waves as a physical method in addition to sodium dodecyl sulfate (SDS) as chemical agents with 0.1% and 1% (w/v) concentrations were examined. Decellularization process was evaluated by nucleus staining with hematoxylin and eosin (H and E) and by staining glycosaminoglycans (GAG) and collagen. Results: The H and E staining indicated that 1% (w/v) SDS in addition to ultrasonic bath for 5 h significantly decreased the cell nucleus residue to lacuna ratio by 66%. Scanning electron microscopy showed that using direct sonication caused formation of micropores on the surface of the sample which results in better penetration of decellularization material and better cell attachment after decellularization. Alcian Blue and Picrosirius Red staining represented GAG and collagen, respectively, which maintained in ECM structure after decellularization by ultrasonic bath and direct sonicator. Conclusion: Ultrasonic bath can help better penetration of the decellularization material into the cartilage. This improves the speed of the decellularization process while it has no significant defect on the structure of the tissue. © 2019 Journal of Medical Signals & Sensors.
Journal Of Medical Signals And Sensors (22287477) 8(3)pp. 170-174
Background: Bacterial sensors are recommended for medical sciences, pharmaceutical industries, food industries, and environmental monitoring due to low cost, high sensitivity, and appropriate response time. There are some advantages of using bacterial spores instead of bacteria in vegetative forms as spores remain alive without any nutrient for a long time and change to vegetative form when a suitable environment is provided for them. Methods: For biosensor fabrication, it is important to define how the bacterial spores are delivered to the substrate media. The main purpose of this paper is an investigation of transferring bacterial spores on a flexible substrate media using a commercial inkjet printer (HP Deskjet 1510). It should be noted that in the previous researches, the special printers were used to transfer bacteria on rigid films. Results: These printed bacterial spores are used as a colorimetric temperature indicator. The custom-made bio-inks are prepared by bacterial spores along with a gelling agent and pH indicator. Conclusions: Finally, transformation of bacterial spores into vegetative bacteria is occurred by changing of temperature. A color change in the bio-prints is demonstrated because the bacterial transformation and growth change the environmental pH to an acidic level. © 2018 Journal of Medical Signals & Sensors | Published by Wolters Kluwer - Medknow
Journal of Food Measurement and Characterization (21934134) 12(1)pp. 441-448
Dormant bacterial spores can sense their environments and under favorable conditions exchange their cycle from spore state to germinated one through the processes of germination and outgrowth. Here, the capability of spore germination is used to design an antibiotic bio-sensing system. Germination assays were carried out by reduction of optical density, release of Dipicolinic acid and respiration test under different germinats and various concentrations of Penicillin as a germination inhibitor. This study showed that although current germinants are not properly useful for germination of Bacillus amyloliquefaciens in starch media, presence of a small amount of cell wall destruction antibiotics (25 µg/ml) can accelerate germination but prevent outgrowth of germinated spores. So, the germinated spores cannot use the starch and stain blue with iodine reagent. This phenomenon is beneficial for detection of antibiotic residues in food and feed which are severe problem for consumers or by giving rise to the expansion of antibiotic resistances. © 2017, Springer Science+Business Media, LLC.
Rabbani, M. ,
Tafazzoli-shadpour, M. ,
Shokrgozar m.a., M.A. ,
Janmaleki, M. ,
Teymoori, M. Tissue Engineering and Regenerative Medicine (17382696) 14(3)pp. 279-286
Recent investigations consider adipose-derived stem cells (ASCs) as a promising source of stem cells for clinical therapies. To obtain functional cells with enhanced cytoskeleton and aligned structure, mechanical stimuli are utilized during differentiation of stem cells to the target cells. Since function of muscle cells is associated with cytoskeleton, enhanced structure is especially essential for these cells when employed in tissue engineering. In this study by utilizing a custom-made device, effects of uniaxial tension (1Hz, 10% stretch) on cytoskeleton, cell alignment, cell elastic properties, and expression of smooth muscle cell (SMC) genes in ASCs are investigated. Due to proper availability of ASCs, results can be employed in cardiovascular engineering when production of functional SMCs in arterial reconstruction is required. Results demonstrated that cells were oriented after 24 hours of cyclic stretch with aligned pseudo-podia. Staining of actin filaments confirmed enhanced polymerization and alignment of stress fibers. Such phenomenon resulted in stiffening of cell body which was quantified by atomic force microscopy (AFM). Expression of SM α-actin and SM22 α-actin as SMC associated genes were increased after cyclic stretch while GAPDH was considered as internal control gene. Finally, it was concluded that application of cyclic stretch on ASCs assists differentiation to SMC and enhances functionality of cells. © 2017, The Korean Tissue Engineering and Regenerative Medicine Society and Springer Science+Business Media Dordrecht.
Applied Food Biotechnology (24234214) 4(2)pp. 79-84
Background and Objective: Time-temperature indicators are used in smart packaging, and described as intelligent tools attached to the label of food products to monitor their timetemperature history. Since the previous studies on microbial time-temperature indicators were only based on pH-dependent changes, and they were long-time response indicators, in the present work, a new microbial time-temperature indicator was designed by using the alphaamylase activity of Bacillus amyloliquefaciens vegetative cells. Material and Methods: The designed time-temperature indicator system consists of Bacillus amyloliquefaciens, specific substrate medium and iodine reagent. The relation of the timetemperature indicator' response to the growth and metabolic activity (starch consumption and production of reduced sugars) of Bacillus amyloliquefaciens was studied. In addition, the temperature dependence of the time-temperature indicator was considered at 8 and 28°C. Finally, in order to adjust time-temperature indicator endpoint, the effect of the inoculum level was investigated at 8°C. Results and Conclusion: In the designed system, a color change of an iodine reagent to yellow progressively occurs due to the starch hydrolysis. The effect of the inoculum level showed the negative linear relationship between the levels of Bacillus amyloliquefaciens inoculated in the medium and the endpoints of the time-temperature indicators. The endpoints were adjusted to 156, 72 and 36 hours at the inoculum levels of 102, 104 and 106 CFU ml-1, respectively. The main advantages of the time-temperature indicator is low cost and application for monitoring the quality of chilled food products. Conflict of interest: The authors declare no conflict of interest.
Rabbani, M. ,
Janmaleki, M. ,
Tafazzoli-shadpour, M. ,
Teymoori, M. ,
Rezvaninejad, S. Tissue Engineering and Regenerative Medicine (17382696) 13(4)pp. 396-402
Adipose derived stem cells (ADSC) are good candidates for the replacement of bone marrow derived mesenchymal stem cells due to their abundance, multipotency property, and easier accessibility. In order to explore the behavior of these cells in response to mechanical stimulation, in this study we have investigated the effects of uniaxial dynamic mechanical loading on ADSC’s morphology. Stem cells derived from the fat tissue of human and after an overnight culture were seeded on a silicone rubber strips. Afterwards, cells were subjected to a uniaxial dynamic loading in three different groups. Cell images were evaluated considering different morphological parameters. Fractal dimension decreased significantly after loading while in control groups there were a significant increase (p<0.05), approving that cyclic strain would lead to more aligned and organized cells. Cell orientation also increased significantly (p<0.05). Moreover cells’ orientation angle, 24 hour after loading does not change compared to the observations immediately after loading, which attests to the practicality of the cyclic strain in functional tissue engineering. Cell width decreased and cell length increased which led to a significant increase in cell shape index (p<0.05). Results confirmed that uniaxial dynamic loading affects cell morphological parameters comparing their values before and after loading. In addition, the number of cycles are also an important factor since different number of cycles lead to different amounts of certain morphological parameters. Conclusively, cyclic strain can be a practical method in the field of functional tissue engineering. © 2016, The Korean Tissue Engineering and Regenerative Medicine Society and Springer Science+Business Media Dordrecht.
Biochemical and Biophysical Research Communications (0006291X) 464(2)pp. 473-479
Alteration in specific inertial conditions can lead to changes in morphology, proliferation, mechanical properties and cytoskeleton of cells. In this report, the effects of hypergravity on morphology of Adipose-Derived Stem Cells (ADSCs) are indicated. ADSCs were repeatedly exposed to discontinuous hypergravity conditions of 10 g, 20 g, 40 g and 60 g by utilizing centrifuge (three times of 20 min exposure, with an interval of 40 min at 1 g). Cell morphology in terms of length, width and cell elongation index and cytoskeleton of actin filaments and microtubules were analyzed by image processing. Consistent changes observed in cell elongation index as morphological change. Moreover, cell proliferation was assessed and mechanical properties of cells in case of elastic modulus of cells were evaluated by Atomic Force Microscopy. Increase in proliferation and decrease in elastic modulus of cells are further results of this study. Staining ADSC was done to show changes in cytoskeleton of the cells associated to hypergravity condition specifically in microfilament and microtubule components. After exposing to hypergravity, significant changes were observed in microfilaments and microtubule density as components of cytoskeleton. It was concluded that there could be a relationship between changes in morphology and MFs as the main component of the cells. © 2015 Elsevier Inc.
Shokrgozar m.a., M.A. ,
Bonakdar, S. ,
Dehghan, M.M. ,
Hojjati emami, S. ,
Montazeri, L. ,
Azari, S. ,
Rabbani, M. Journal of Materials Science: Materials in Medicine (15734838) 24(10)pp. 2449-2460
Polyvinyl alcohol (PVA) hydrogel chains were crosslinked by urethane pre-polymer (PPU) in order to fabricate a new substitute for cartilage lesions. The microscopy images showed that the cultured chondrocytes had spherical morphology on PVA-PPU sample after 4 weeks of isolation in vitro. The alcian blue and safranin O staining proved the presence of proteoglycan on the surface of PVA-PPU sample secreted by cultured chondrocytes. This was confirmed by the detection of sulfate ions in the wavelength dispersive X-ray (WDX) analysis. In addition, the expression of collagen type II and aggrecan were observed in chondrocytes cultured on PVA-PPU by RT-PCR. Moreover, the implantation of the PVA-PPU sample with autologous cultured chondrocytes revealed the formation of neocartilage tissue in a rabbit model during 12 weeks follow up. In conclusion, the results verified that isolated chondrocytes cultured on PVA-PPU retain their original phenotype and this composition can be considered as promising substrate for cartilage tissue engineering. © 2013 Springer Science+Business Media New York.
Goli-malekabadi, Z. ,
Tafazzoli-shadpour, M. ,
Rabbani, M. ,
Janmaleki, M. Biomedizinische Technik (1862278X) 56(5)pp. 259-265
Human mesenchymal stem cells (hMSCs) are capable of self-renewal and differentiation into various cell lineages. Mechanical stimuli have been shown to regulate function of stem cells through alteration in morphology and structure. The aim of this study was to evaluate and compare effects of uniaxial static stretch and combined static-dynamic stretch on the orientation, regulation and cytoskeletal structure of hMSCs. Mean values of topological were calculated before and after loadings. Moreover, fractal dimension (FD) was employed to quantify alterations in shape complexity of the cells. Internal cytoskeletal structure of cells was observed by actin filament staining. Results demonstrated a statistically significant change in cell topology and FD due to 10% static-dynamic stretch after 24 h. Static stretch was not as influential as dynamic loading. Whereas for combined static-dynamic stretch systemic alignment of cells was detected, in the static test group local alignment of actin fibers was observed, although the entire cell network was not totally aligned in a specific direction. It was concluded that dynamic stretch leads to cytoskeletal alignment and repolarization of hMSCs, whereas static stretch does not. Under static stretch hMSCs proliferated more than under dynamic stretch. Results can be applied in tissue engineering when functionalization of stem cells is required. © 2011 by Walter de Gruyter Berlin Boston.
