Bioengineering / Biyomühendislik

Permanent URI for this collectionhttps://hdl.handle.net/11147/4529

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Start date: 2020Institution Author: search.filters.institutionAuthor.Aldemir Dikici, Betül

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Now showing 1 - 5 of 5
  • Article
    Citation - WoS: 18
    Citation - Scopus: 17
    Modifying Pickering Polymerized High Internal Phase Emulsion Morphology by Adjusting Particle Hydrophilicity
    (Elsevier, 2024) Durgut, Enes; Zhou, Muchu; Dikici, Betuel Aldemir; Foudazi, Reza; Claeyssens, Frederik
    This study investigates the use of submicron polymeric particles with varying crosslinking densities as the sole stabilizer for producing Polymerized High Internal Phase Emulsions (PolyHIPE). We establish a direct correlation between the crosslinking density and the hydrophilicity of the polymer particles. The hydrophilicity of these particles significantly influences the morphology and rheology of HIPEs. These differences manifest as various morphological variations in the resulting PolyHIPE templates. It was discovered that by increasing the crosslinker weight percentage in the particles from 0 % to 100 %, PolyHIPEs with semi-open, open, and closed porous structures can be obtained. Furthermore, non-crosslinked particles were observed to dissolve in the continuous phase, acting as macromolecular surfactants that generate small pores akin to surfactant-stabilized structures in PolyHIPE. These findings offer fresh insights into the relationship between particle localization at the interface, HIPE rheology, and the formation of pore throats in Pickering PolyHIPEs, leading to the creation of either closed or open porous networks. Additionally, interfacial rheological results demonstrate that particles synthesized with varying monomer-to-crosslinker ratios exhibit different interfacial elasticities, which are linked to PolyHIPE morphology.
  • Article
    Citation - WoS: 27
    Citation - Scopus: 27
    In Vivo Bone Regeneration Capacity of Multiscale Porous Polycaprolactone-Based High Internal Phase Emulsion (polyhipe) Scaffolds in a Rat Calvarial Defect Model
    (American Chemical Society, 2023) Aldemir Dikici, Betül; Chen, Min-Chia; Dikici, Serkan; Chiu, Hsien-Chung; Claeyssens, Frederik
    Globally, one of the most common tissue transplantationproceduresis bone grafting. Lately, we have reported the development of polymerizedhigh internal phase emulsions (PolyHIPEs) made of photocurable polycaprolactone(4PCLMA) and shown their potential to be used as bone tissue engineeringscaffolds in vitro. However, it is essential to evaluatethe in vivo performance of these scaffolds to investigatetheir potential in a clinically more relevant manner. Therefore, inthis study, we aimed to compare in vivo performancesof macroporous (fabricated using stereolithography), microporous (fabricatedusing emulsion templating), and multiscale porous (fabricated usingemulsion templating and perforation) scaffolds made of 4PCLMA. Also,3D-printed macroporous scaffolds (fabricated using fused depositionmodeling) made of thermoplastic polycaprolactone were used as a control.Scaffolds were implanted into a critical-sized calvarial defect, animalswere sacrificed 4 or 8 weeks after implantation, and the new boneformation was assessed by micro-computed tomography, dental radiography,and histology. Multiscale porous scaffolds that include both micro-and macropores resulted in higher bone regeneration in the defectarea compared to only macroporous or only microporous scaffolds. Whenone-grade porous scaffolds were compared, microporous scaffolds showedbetter performance than macroporous scaffolds in terms of mineralizedbone volume and tissue regeneration. Micro-CT results revealed thatwhile bone volume/tissue volume (Bv/Tv) values were 8 and 17% at weeks4 and 8 for macroporous scaffolds, they were significantly higherfor microporous scaffolds, with values of 26 and 33%, respectively.Taken together, the results reported in this study showed the potentialapplication of multiscale PolyHIPE scaffolds, in particular, as apromising material for bone regeneration.
  • Article
    Citation - WoS: 14
    Citation - Scopus: 16
    Synergistic Effect of Type and Concentration of Surfactant and Diluting Solvent on the Morphology of Emulsion Templated Matrices Developed as Tissue Engineering Scaffolds
    (Elsevier, 2022) Claeyssens, Frederik; Aldemir Dikici, Betül; Dikici, Serkan
    Emulsion templating is an advantageous route for the fabrication of tissue engineering scaffolds. Emulsions are mostly stabilised using surfactants, and the performances of the surfactants depend on various parameters such as emulsification temperature and the presence of the electrolytes. In this study, we suggest that diluting solvent type also has a dramatic impact on the efficiency of the surfactant and morphology of the polymerised emulsions. For this, morphologies of polycaprolactone methacrylate-based polymerised emulsions, which are designed for tissue engineering applications and in vitro biocompatibilities, were shown by our group, prepared using four different surfactants, and three different solvents were investigated. Results showed that the diluting solvent used in the emulsion composition has a strong impact on the performance of the surfactant and consequently on the morphology of polymerised emulsions. Increasing surfactant concentration and diluting solvent volume have an opposite impact on the characteristics of emulsions. Scaffolds with average pore sizes changing from 10 to 78 μm could be fabricated. Establishing these relations enables us to have control over the overall morphology of polymerised emulsions and precisely engineer them for specific tissue engineering applications by tuning solvent and surfactant type and concentration.
  • Article
    Citation - WoS: 46
    Citation - Scopus: 46
    Thiolene- and Polycaprolactone Methacrylate-Based Polymerized High Internal Phase Emulsion (polyhipe) Scaffolds for Tissue Engineering
    (American Chemical Society, 2022) Aldemir Dikici, Betül; Malayeri, Atra; Sherborne, Colin; Dikici, Serkan; Paterson, Thomas; Dew, Lindsey; Claeyssens, Frederik
    Highly porous emulsion templated polymers (PolyHIPEs) provide a number of potential advantages in the fabrication of scaffolds for tissue engineering and regenerative medicine. Porosity enables cell ingrowth and nutrient diffusion within, as well as waste removal from, the scaffold. The properties offered by emulsion templating alone include the provision of high interconnected porosity, and, in combination with additive manufacturing, the opportunity to introduce controlled multiscale porosity to complex or custom structures. However, the majority of monomer systems reported for PolyHIPE preparation are unsuitable for clinical applications as they are nondegradable. Thiol-ene chemistry is a promising route to produce biodegradable photocurable PolyHIPEs for the fabrication of scaffolds using conventional or additive manufacturing methods; however, relatively little research has been reported on this approach. This study reports the groundwork to fabricate thiol- and polycaprolactone (PCL)-based PolyHIPE materials via a photoinitiated thiolene click reaction. Two different formulations, either three-arm PCL methacrylate (3PCLMA) or four-arm PCL methacrylate (4PCLMA) moieties, were used in the PolyHIPE formulation. Biocompatibility of the PolyHIPEs was investigated using human dermal fibroblasts (HDFs) and human osteosarcoma cell line (MG-63) by DNA quantification assay, and developed PolyHIPEs were shown to be capable of supporting cell attachment and viability.
  • Article
    Citation - WoS: 34
    Citation - Scopus: 34
    Decellularised Extracellular Matrix Decorated Pcl Polyhipe Scaffolds for Enhanced Cellular Activity, Integration and Angiogenesis
    (Royal Society of Chemistry, 2021) Dikici, Serkan; Aldemir Dikici, Betül; MacNeil, Sheila; Claeyssens, Frederik
    Wound healing involves a complex series of events where cell-cell and cell-extracellular matrix (ECM) interactions play a key role. Wounding can be simple, such as the loss of the epithelial integrity, or deeper and more complex, reaching to subcutaneous tissues, including blood vessels, muscles and nerves. Rapid neovascularisation of the wounded area is crucial for wound healing as it has a key role in supplying oxygen and nutrients during the highly demanding proliferative phase and transmigration of inflammatory cells to the wound area. One approach to circumvent delayed neovascularisation is the exogenous use of pro-angiogenic factors, which is expensive, highly dose-dependent, and the delivery of them requires a very well-controlled system to avoid leaky, highly permeable and haemorrhagic blood vessel formation. In this study, we decorated polycaprolactone (PCL)-based polymerised high internal phase emulsion (PolyHIPE) scaffolds with fibroblast-derived ECM to assess fibroblast, endothelial cell and keratinocyte activity in vitro and angiogenesis in ex ovo chick chorioallantoic membrane (CAM) assays. Our results showed that the inclusion of ECM in the scaffolds increased the metabolic activity of three types of cells that play a key role in wound healing and stimulated angiogenesis in ex ovo CAM assays over 7 days. Herein, we demonstrated that fibroblast-ECM functionalised PCL PolyHIPE scaffolds appear to have great potential to be used as an active wound dressing to promote angiogenesis and wound healing.