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Publication Metadata only 3D printed biodegradable polyurethaneurea elastomer recapitulates skeletal muscle structure and function(American Chemical Society (ACS), 2021) Gokyer, Seyda; Berber, Emine; Vrana, Engin; Orhan, Kaan; Abou Monsef, Yanad; Guvener, Orcun; Zinnuroglu, Murat; Oto, Cagdas; Huri, Pinar Yilgor; Department of Chemistry; Department of Chemistry; Yılgör, Emel; Yılgör, İskender; Researcher; Faculty Member; Department of Chemistry; College of Sciences; College of Sciences; N/A; 24181Effective skeletal muscle tissue engineering relies on control over the scaffold architecture for providing muscle cells with the required directionality, together with a mechanical property match with the surrounding tissue. Although recent advances in 3D printing fulfill the first requirement, the available synthetic polymers either are too rigid or show unfavorable surface and degradation profiles for the latter. In addition, natural polymers that are generally used as hydrogels lack the required mechanical stability to withstand the forces exerted during muscle contraction. Therefore, one of the most important challenges in the 3D printing of soft and elastic tissues such as skeletal muscle is the limitation of the availability of elastic, durable, and biodegradable biomaterials. Herein, we have synthesized novel, biocompatible and biodegradable, elastomeric, segmented polyurethane and polyurethaneurea (TPU) copolymers which are amenable for 3D printing and show high elasticity, low modulus, controlled biodegradability, and improved wettability, compared to conventional polycaprolactone (PCL) and PCL-based TPUs. The degradation profile of the 3D printed TPU scaffold was in line with the potential tissue integration and scaffold replacement process. Even though TPU attracts macrophages in 2D configuration, its 3D printed form showed limited activated macrophage adhesion and induced muscle-like structure formation by C2C12 mouse myoblasts in vitro, while resulting in a significant increase in muscle regeneration in vivo in a tibialis anterior defect in a rat model. Effective muscle regeneration was confirmed with immunohistochemical assessment as well as evaluation of electrical activity produced by regenerated muscle by EMG analysis and its force generation via a custom-made force transducer. Micro-CT evaluation also revealed production of more muscle-like structures in the case of implantation of cell-laden 3D printed scaffolds. These results demonstrate that matching the tissue properties for a given application via use of tailor-made polymers can substantially contribute to the regenerative outcomes of 3D printed tissue engineering scaffolds.Publication Restricted A numerical and experimental design of high entropy alloys for biomedical applications(Koç University, 2022) Chatroudi, Shabnam Fadaei; Canadinç, Demircan; 0000-0001-9961-7702; Koç University Graduate School of Sciences and Engineering; Materials Science and Engineering; 23433Publication Restricted A portable blood coagulation time measurement platform with fiber-optic based disposable cartridge(Koç University, 2016) Yaraş, Yusuf Samet; Ürey, Hakan; 0000-0002-2031-7967; Koç University Graduate School of Sciences and Engineering; Electrical and Electronics Engineering; 8579Publication Metadata only A review of bioresorbable implantable medical devices: materials, fabrication, and implementation(Wiley, 2020) N/A; N/A; Department of Mechanical Engineering; Department of Mechanical Engineering; Singh, Rahul; Bathaei, Mohammad Javad; İstif, Emin; Beker, Levent; PhD Student; PhD Student; Researcher; Faculty Member; Department of Mechanical Engineering; Graduate School of Sciences and Engineering; Graduate School of Sciences and Engineering; College of Engineering; College of Engineering; N/A; N/A; 354990; 308798Implantable medical devices (IMDs) are designed to sense specific parameters or stimulate organs and have been actively used for treatment and diagnosis of various diseases. IMDs are used for long-term disease screening or treatments and cannot be considered for short-term applications since patients need to go through a surgery for retrieval of the IMD. Advances in bioresorbable materials has led to the development of transient IMDs that can be resorbed by bodily fluids and disappear after a certain period. These devices are designed to be implanted in the adjacent of the targeted tissue for predetermined times with the aim of measurement of pressure, strain, or temperature, while the bioelectronic devices stimulate certain tissues. They enable opportunities for monitoring and treatment of acute diseases. To realize such transient and miniaturized devices, researchers utilize a variety of materials, novel fabrication methods, and device design strategies. This review discusses potential bioresorbable materials for each component in an IMD followed by programmable degradation and safety standards. Then, common fabrication methods for bioresorbable materials are introduced, along with challenges. The final section provides representative examples of bioresorbable IMDs for various applications with an emphasis on materials, device functionality, and fabrication methods.Publication Metadata only An exploration of plastic deformation dependence of cell viability and adhesion in metallic implant materials(Elsevier, 2016) Gerstein, G.; Maier, H. J.; N/A; N/A; N/A; N/A; Department of Mechanical Engineering; Uzer, Benay; Toker, Sıdıka Mine; Cingöz, Ahmet; Önder, Tuğba Bağcı; Canadinç, Demircan; Researcher; PhD Student; Researcher; Faculty Member; Faculty Member; Department of Mechanical Engineering; N/A; Graduate School of Sciences and Engineering; Graduate School of Health Sciences; School of Medicine; College of Engineering; N/A; 255504; N/A; 184359; 23433The relationship between cell viability and adhesion behavior, and micro-deformation mechanisms was investigated on austenitic 316L stainless steel samples, which were subjected to different amounts of plastic strains (5%, 15%, 25%, 35% and 60%) to promote a variety in the slip and twin activities in the microstructure. Confocal laser scanning microscopy (CLSM) and field emission scanning electron microscopy (FESEM) revealed that cells most favored the samples with the largest plastic deformation, such that they spread more and formed significant filopodial extensions. Specifically, brain tumor cells seeded on the 35% deformed samples exhibited the best adhesion performance, where a significant slip activity was prevalent, accompanied by considerable slip-twin interactions. Furthermore, maximum viability was exhibited by the cells seeded on the 60% deformed samples, which were particularly designed in a specific geometry that could endure greater strain values. Overall, the current findings open a new venue for the production of metallic implants with enhanced biocompatibility, such that the adhesion and viability of the cells surrounding an implant can be optimized by tailoring the surface relief of the material, which is dictated by the micro-deformation mechanism activities facilitated by plastic deformation imposed by machining.Publication Metadata only Application of the finite element method in spinal implant design and manufacture(Woodhead Publ Ltd, 2012) N/A; Department of Mechanical Engineering; Zafarparandeh, Iman; Lazoğlu, İsmail; PhD Student; Faculty Member; Department of Mechanical Engineering; Graduate School of Sciences and Engineering; College of Engineering; N/A; 179391This chapter reviews the application of the finite element (FE) method in designing and manufacturing spinal implants. The structure of the chapter is built upon the procedure of creating the FE model for the human spine, which consists of establishing the FE model for each component of the spine, including mesh generation and material property, verification, validation and, finally, implant design process. Each part of the spine FE model is discussed from the simulation point of view and available models are introduced. For the implant design, some examples are chosen from the literature, which are also being used widely in the medical industry.Publication Restricted Biocompatibility- mechanical property- microstructure relationship in conventional and potential biomedical alloys(Koç University, 2014) Toker, Sıdıka Mine; Canadinç, Demircan; 0000-0001-9961-7702; Koç University Graduate School of Sciences and Engineering; Mechanical Engineering; 23433Publication Restricted Design of a left ventricular assist device: heart turcica centrifugal(Koç University, 2009) Bıyıklı, Emre; Lazoğlu, İsmail; 0000-0002-8316-9623; Koç University Graduate School of Sciences and Engineering; Mechanical Engineering; 179391Publication Restricted Design of functional materials via emulsion templating energy and biomedical applications(Koç University, 2017) Aydın, Derya; Kızılel, Seda; 0000-0001-9092-2698; Koç University Graduate School of Sciences and Engineering; Chemical and Biological Engineering; 28376Publication Restricted Development of a novel hybrid frost detection and defrost system for refrigeration systems and its applications(Koç University, 2021) Malik, Anjum Naeem; Lazoğlu, İsmail; 0000-0002-8316-9623; Koç University Graduate School of Sciences and Engineering; Bio-Medical Sciences and Engineering; 179391
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