January 2025
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52 Reads
Journal of Cleaner Production
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January 2025
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52 Reads
Journal of Cleaner Production
January 2025
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34 Reads
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1 Citation
ChemPhysMater
February 2024
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58 Reads
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1 Citation
There is a growing need for sensing materials that can provide multiple sensing capabilities for wearable devices, implantable sensors, and diagnostics tools. As complex human physiology requires materials that can simultaneously detect and respond to slow and fast pressure fluctuations. Mimicking the slow adaptive (SA) and fast adaptive (FA) mechanoreceptors in skin can lead to the development of dual sensing electrospun polymer nanocomposites for biomedical applications. These dual sensing nanocomposites can provide simultaneous sensing of both slow and fast pressure fluctuations, making them ideal for applications such as monitoring vital signs, detecting a wider range of movements and pressures. Here we develop a novel dual sensing PVDF-HFP-based nanocomposite that combines the advantages of capacitive and piezoelectric properties through controling electrospinning environment and processing parameters, polymer solution composition, and addition of nucleating agents such as Carbon Black (CB) to enhance the crystalline development of β-phase, fibre thickness, and morphology. The developed PVDF-HFP/CB nanocomposite presents and response to both slow and fast pressure fluctuations with high capacitance (5.37 nF) and output voltage (1.51 V) allowing for accurate and reliable measurements.
June 2023
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149 Reads
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2 Citations
International Journal of Bioprinting
Polyethylene terephthalate glycol (PETG) is a difficult-to-spin material, and no previous papers have reported the correct conditions to create PETG meshes. To address this issue, a preliminary study on the solubility and electrospinnability of PETG using a range of solvent system was conducted and a Teas graph was established to select the ideal solvent system. Based on these preliminary results, electrospun PETG fibers were produced using a highly volatile binary solvent system consisting of dichloromethane (DCM) and trifluoroacetic acid (TFA). Produced meshes were extensively characterized, and the results demonstrated for the first time the ability of electrospun PETG meshes to support the inoculation and germination of yellow rust spores, thus confirming that PETG is an ideal material to be used for the fabrication of agriculture biosensors. The results also showed that the best solvent split was 85/15 (DCM/TFA).
August 2022
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192 Reads
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124 Citations
Polymers
Polycaprolactone (PCL) is widely used in tissue engineering due to its interesting properties, namely biocompatibility, biodegradability, elastic nature, availability, cost efficacy, and the approval of health authorities such as the American Food and Drug Administration (FDA). The PCL degradation rate is not the most adequate for specific applications such as skin regeneration due to the hydrophobic nature of bulk PCL. However, PCL electrospun fiber meshes, due to their low diameters resulting in high surface area, are expected to exhibit a fast degradation rate. In this work, in vitro and in vivo degradation studies were performed over 90 days to evaluate the potential of electrospun PCL as a wound dressing. Enzymatic and hydrolytic degradation studies in vitro, performed in a static medium, demonstrated the influence of lipase, which promoted a rate of degradation of 97% for PCL meshes. In an in vivo scenario, the degradation was slower, although the samples were not rejected, and were well-integrated in the surrounding tissues inside the subcutaneous pockets specifically created.
July 2022
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290 Reads
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22 Citations
Journal of Functional Biomaterials
The use of biocompatible and biodegradable porous scaffolds produced via additive manufacturing is one of the most common approaches in tissue engineering. The geometric design of tissue engineering scaffolds (e.g., pore size, pore shape, and pore distribution) has a significant impact on their biological behavior. Fluid flow dynamics are important for understanding blood flow through a porous structure, as they determine the transport of nutrients and oxygen to cells and the flushing of toxic waste. The aim of this study is to investigate the impact of the scaffold architecture, pore size and distribution on its biological performance using Computational Fluid Dynamics (CFD). Different blood flow velocities (BFV) induce wall shear stresses (WSS) on cells. WSS values above 30 mPa are detrimental to their growth. In this study, two scaffold designs were considered: rectangular scaffolds with uniform square pores (300, 350, and 450 µm), and anatomically designed circular scaffolds with a bone-like structure and pore size gradient (476–979 µm). The anatomically designed scaffolds provided the best fluid flow conditions, suggesting a 24.21% improvement in the biological performance compared to the rectangular scaffolds. The numerical observations are aligned with those of previously reported biological studies.
October 2021
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454 Reads
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37 Citations
International Journal of Molecular Sciences
The practice of combining external stimulation therapy alongside stimuli-responsive bio-scaffolds has shown massive potential for tissue engineering applications. One promising example is the combination of electrical stimulation (ES) and electroactive scaffolds because ES could enhance cell adhesion and proliferation as well as modulating cellular specialization. Even though electroactive scaffolds have the potential to revolutionize the field of tissue engineering due to their ability to distribute ES directly to the target tissues, the development of effective electroactive scaffolds with specific properties remains a major issue in their practical uses. Conductive polymers (CPs) offer ease of modification that allows for tailoring the scaffold's various properties, making them an attractive option for conductive component in electroactive scaffolds. This review provides an up-to-date narrative of the progress of CPs-based electroactive scaffolds and the challenge of their use in various tissue engineering applications from biomaterials perspectives. The general issues with CP-based scaffolds relevant to its application as electroactive scaffolds were discussed, followed by a more specific discussion in their applications for specific tissues, including bone, nerve, skin, skeletal muscle and cardiac muscle scaffolds. Furthermore, this review also highlighted the importance of the manufacturing process relative to the scaffold's performance, with particular emphasis on additive manufacturing, and various strategies to overcome the CPs' limitations in the development of electroactive scaffolds.
April 2021
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754 Reads
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34 Citations
Molecules
Electroactive biomaterials are fascinating for tissue engineering applications because of their ability to deliver electrical stimulation directly to cells, tissue, and organs. One particularly attractive conductive filler for electroactive biomaterials is silver nanoparticles (AgNPs) because of their high conductivity, antibacterial activity, and ability to promote bone healing. However, production of AgNPs involves a toxic reducing agent which would inhibit biological scaffold performance. This work explores facile and green synthesis of AgNPs using extract of Cilembu sweet potato and studies the effect of baking and precursor concentrations (1, 10 and 100 mM) on AgNPs’ properties. Transmission electron microscope (TEM) results revealed that the smallest particle size of AgNPs (9.95 ± 3.69 nm) with nodular morphology was obtained by utilization of baked extract and ten mM AgNO3. Polycaprolactone (PCL)/AgNPs scaffolds exhibited several enhancements compared to PCL scaffolds. Compressive strength was six times greater (3.88 ± 0.42 MPa), more hydrophilic (contact angle of 76.8 ± 1.7°), conductive (2.3 ± 0.5 × 10−3 S/cm) and exhibited anti-bacterial properties against Staphylococcus aureus ATCC3658 (99.5% reduction of surviving bacteria). Despite the promising results, further investigation on biological assessment is required to obtain comprehensive study of this scaffold. This green synthesis approach together with the use of 3D printing opens a new route to manufacture AgNPs-based electroactive with improved anti-bacterial properties without utilization of any toxic organic solvents.
January 2021
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40 Reads
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9 Citations
Methods in molecular biology (Clifton, N.J.)
The design of optimized scaffolds for tissue engineering and regenerative medicine is a key topic of current research, as the complex macro- and micro-architectures required for scaffold applications depend not only on the mechanical properties but also on the physical and molecular queues of the surrounding tissue within the defect site. Thus, the prediction of optimal features for tissue engineering scaffolds is very important, for both its physical and biological properties.The relationship between high scaffold porosity and high mechanical properties is contradictory, as it becomes even more complex due to the scaffold degradation process. Biomimetic design has been considered as a viable method to design optimum scaffolds for tissue engineering applications. In this research work, the scaffold designs are based on biomimetic boundary-based bone micro-CT data. Based on the biomimetic boundaries and with the aid of topological optimization schemes, the boundary data and given porosity is used to obtain the initial scaffold designs. In summary, the proposed scaffold design scheme uses the principles of both the boundaries and porosity of the micro-CT data with the aid of numerical optimization and simulation tools.
November 2020
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128 Reads
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22 Citations
The properties of the surrounding cell environment are major determinants of cell response in 3D. However, the ability to unravel how these cues dictate the biological function in bioprinted constructs is limited by the lack of extracellular matrix (ECM)‐mimetic bioinks with fully controllable properties. In this study, a multifunctional bioink that uniquely combines the independent control over the biochemical and biophysical cues that regulate cell fate with the bioorthogonal nature of thiol–norbornene photoclick chemistry is designed for the extrusion bioprinting of bioinspired 3D cellular niches with tunable properties. The bioink rheology is controlled by ionic gelation, being dependent on both the type and content of divalent ions (calcium and barium), while the mechanical and biochemical properties of hydrogels are tailored via a post printing thiol–ene reaction. Bioprinted cell‐adhesive and protease‐degradable hydrogels modulate cell proliferation and ECM deposition in a matrix‐stiffness dependent manner over 14 days of culture regardless of cell spreading, demonstrating the ability to probe the effect of matrix cues on cell response. This bioink can be used as a versatile platform where building blocks can be rationally combined for the bioprinting of functional cell‐ and tissue‐specific constructs with controlled cellular behavior.
... 22 But, PCL fibers were seen initially degraded in the presence of enzymatic medium resulting in increased surface roughness and decreased fibre diameter. 23 Such degradation also resulted in undesirable gradual increase in young's modulus, and increase in crystallinity. 23 This attributes may limit the suitability in tissue model application of pure PCL. ...
August 2022
Polymers
... Many previous CFD simulation research works used a Newtonian fluid material such as water to predict the flow properties of permeable BTE scaffolds [58][59][60]. However, having a non-Newtonian fluid of varying viscosity, such as blood-due to constituents of plasma, platelets, white blood cells (WBCs), and red blood cells (RBCs)-gives realistic predictions of flow properties [61][62][63]. Different blood viscosity models such as Casson, Cross, Powell-Erying, Carreau, Carreau-Yasuda [64,65], Generalised power law, and Power law have been applied in CFD simulation research applications. The power law model is the simplest model, which requires only two parameters: consistency index and power law index, and other non-Newtonian models require four to five parameters, such as zero shear rate viscosity, infinite shear rate viscosity, yield stress and relaxation time [66]. ...
July 2022
Journal of Functional Biomaterials
... Articular cartilage and spinal cord networks are embedded within proteoglycans in an organized manner and so on. Several recent developments are reshaping the field [20,21]. CONCLUSION 3D scaffolds represent a cornerstone of modern tissue engineering, bridging the gap between biological systems and synthetic materials to promote tissue repair and regeneration. ...
October 2021
International Journal of Molecular Sciences
... A composite premix was prepared using the melt blending approach [46]. The variants of the composite premix developed in this study are as follows: pure PCL (without fillers); PCL_FNR_0.013 ...
April 2021
Molecules
... The hardware ( Fig. 5.2b) consists of a 6-axis robotic arm (ABB IRB 2400) used to guide a novel printing head [43]. This robot reaches a maximum of 1.55 m with a handling capacity of 16 kg, and so the deposition system was developed considering the following constraints: ...
October 2020
... In addition, this polymer has a non-specific nature, not responding to cells like alginate. Pereira and colleagues [131] emphasized the advantages of this characteristic in the development of biofunctionalized bioinks capable of guiding cell behaviour for specific TE applications. A multicomponent system consisting of a bioink with a single-polymer backbone of NOR-functionalized pectin (pect-NOR) was developed. ...
November 2020
... Degradable biomaterials: Research then turned to degradable biomaterials, allowing The second element is the scaffolding, which is used to give shape to the tissue/organ to be reconstructed but whose nature has significant implications; in particular, it provides adequate mechanical resistance or signals promoting proliferation and differentiation of Bioengineering 2024, 11, 230 6 of 23 the cells, which will be used [79][80][81][82]. There is a vast variety of materials that can be used and have been described [16,44]. ...
January 2021
Methods in molecular biology (Clifton, N.J.)
... Los modelos tridimensionales usados en la fabricación de andamios se diseñan frecuentemente en función de las tecnologías de fabricación existentes y en cumplimiento con las normas y requisitos mecánicos mínimos del hueso humano (Ramakrishna et al., 2001). Los modelos en algunos casos son celdas unitarias con geometrías simples, que cuando se unen forman modelos del tamaño deseado para mejorar las propiedades mecánicas del andamio (Cheah et al., 2003;Egan, 2019;Wang et al., 2016). De esta forma se estudia desde un punto de vista microscópico el andamio, la microestructura y como afecta también a las propiedades mecánicas (Adachi et al., 2006). ...
May 2016
... Rapid prototyping, economic production, reuse of waste material and the ability to fabricate complex geometries and also less need for labour are the main properties of 3D printing systems and advantages, compared with traditional methods (Fasel et al., 2020;Gonabadi et al., 2020). Thanks to these superior capabilities, today, additive manufacturing technology has been used in many fields such as power and energy, building, automotive, aerospace (Fasel et al., 2020;Shi et al., 2020) and biomedical applications (Daskalakis et al., 2020;Huang et al., 2020aHuang et al., , 2020bVyas et al., 2020). ...
January 2020
... Honey has antibacterial properties due to the production of hydrogen peroxide and ROS, high osmolality of sugar, and low pH. Aslan et al. (2020) investigated for the first time the use of Surgihoney ® , a medical-grade honey with antibacterial properties, for wound healing applications. Acetic acid was used as non-toxic solvent for electrospinning. ...
January 2020