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Bioactive Ceramics and Metals for Regenerative Engineering
Published in Yusuf Khan, Cato T. Laurencin, Regenerative Engineering, 2018
Changchun Zhou, Xiangfeng Li, Junqiu Cheng, Hongsong Fan, Xingdong Zhang
The development of regenerative engineering provides an effective approach for tissue repair and regeneration. The selection of scaffold material and structure optimization is important to fully mimic the 3D network structure of natural tissue. Bioactive ceramics and metals are drawing more attention due to their excellent biocompatibility and osteogenesis. Thanks to the founding of bioactive ceramics with osteoinductivity, more focus is on the design of material bioactivity to induce tissue regeneration, to realize the replacement of damaged tissue by the regenerated new tissue. To achieve the objective, on the one hand, it is necessary to explore the responding mechanism between biomaterials and cells on a molecular and genetic level to supply principles for improving material bioactivity; on the other hand, it is necessary to probe new material designs and fabrication techniques to obtain tunable and optimized mechanical and degradation properties. For metals with superior mechanical properties, a future revolution might come from biodegradable metal implants. By optimizing the bioactivity of metals to achieve specific biological function such as osteoinduction and regulation of metal degradation, biometals are also expected to be able to achieve bone tissue regeneration in the future.
Nanostructured Biomaterials for Load-Bearing Applications
Published in Ashwani Kumar, Mangey Ram, Yogesh Kumar Singla, Advanced Materials for Biomechanical Applications, 2022
Tissue engineering and regenerative medicine aim to repair tissue and/or regeneration with the help of stem cells, scaffolds, growth and signaling factors. Tissue engineering serves as the alternate way to resolve orthopedic-related problems by reducing the limitations of traditional interventional methods. The effective ways of accomplishing tissue engineering include cell-based therapies, scaffold material implementation, growth factors and bioactive molecules delivery. The notable features of the materials to be used in scaffolds are biocompatibility, bioresorbability, mechanical properties and porosity.
Nanotechnology for Tissue Engineering and Regenerative Medicine
Published in Šeila Selimovic, Nanopatterning and Nanoscale Devices for Biological Applications, 2017
Şükran Şeker, Y. Emre Arslan, Serap Durkut, A. Eser Elçin, Y. Murat Elçin
Over the course of the last decades, the electrostatic fiber formation technique, also known as electrospinning, has received great interest due to its outstanding properties such as ease of operation and versatility, while being inexpensive, scalable, and reliable. The process allows the fabrication of fibers at the nano/microscale from a wide range of synthetic and natural polymers. The well-known technique was first documented in 1897 by Rayleigh and studied by Zeleny in 1914 [14]. Formhals acquired a series of patents in 1934 [15]. Utilizing this material processing method, ultrafine polymer fibers with diameters ranging from 2 nm to several micrometers can be achieved. Nowadays there are a myriad of commercially available electro-spun polymers for research and medical use. Electrospinning can be successfully performed using many kinds of polymers. Electrospun polymer meshes are used in a wide range of applications such as filtration devices, textiles, electrical and optical components, sensors, pharmaceuticals, biotechnology, environmental engineering, defense, and security [16]. Another promising field of application is the tissue-engineering approach for regenerative medicine. Owing to their unique properties, such as smaller pores and higher surface area, electrospun fibers have been successfully used as tissue engineering scaffolds [17]. Nano/microfibrous tissue engineering scaffolds can be fabricated from a variety of natural and synthetic polymers, including poly(lactic acid), poly(urethane), silk fibroin, collagen, hyaluronic acid, chitosan/ collagen, and cellulose. To increase the yield of nanofiber production, techniques such as multiple spinnerets or nozzle systems, and bottom-up gas electrospinning (Figure 14.2) (known as bubble electrospinning in the literature) have been developed [18].
Novel electrospun conduit based on polyurethane/collagen enhanced by nanobioglass for peripheral nerve tissue engineering
Published in Journal of Biomaterials Science, Polymer Edition, 2022
Somayeh Tofighi Nasab, Nasim Hayati Roodbari, Vahabodin Goodarzi, Hossein Ali Khonakdar, Kourosh Mansoori, Mohammad Reza Nourani
Peripheral nerve injury (PNI) is a clinical issue that leads to long-term organ dysfunction. The main therapeutic goal for the severed peripheral nerves is to reconstruct the extension of the damaged nerve to regenerate and establish physiological communication. The use of autograft (a gold-standard method) is considered an effective method for repairing injured nerves, nevertheless, due to some limitations, the use of this approach is limited, and the long waiting time for organ and tissue transplantations as well as disease transmission urges a need for a new method to overcome these limitations [1]. Besides, recipients of this type of transplant must receive immunosuppressive agents for the entire life span, regardless of the high risk of infection, tumor formation, and adverse side effects [2]. As one of the leading methods in modern medicine, tissue engineering is a rapidly growing field of research. In order to accomplish tissue regeneration, three key factors must be taken into account, namely cells, scaffolds, and biomolecules, such as growth factors and genes [3]. In tissue engineering, there is a permanent solution for the treatment of impaired tissues, so there is no need for complementary therapies, and as a result, treatment costs are greatly reduced [4]. Although much research has been performed over the past century to seek new strategies to repair peripheral nerves, there is currently no satisfactory method to meet the desired criteria for peripheral nerve recovery.
The individual and combined effects of spaceflight radiation and microgravity on biologic systems and functional outcomes
Published in Journal of Environmental Science and Health, Part C, 2021
Jeffrey S. Willey, Richard A. Britten, Elizabeth Blaber, Candice G.T. Tahimic, Jeffrey Chancellor, Marie Mortreux, Larry D. Sanford, Angela J. Kubik, Michael D. Delp, Xiao Wen Mao
The role of gravity in maintaining tissue homeostasis has become apparent with expanded study examining the effects of spaceflight on mammalian physiology. Dysfunction in stem cell populations contribute to many Earth-based disease conditions and can be enhanced by aging, oxidative stress, and genetic predisposition.206,207 Adult stem cell populations are found in multiple physiological systems throughout the body and are surrounded by a highly organized and regulated microenvironment consisting of supporting cells and factors, resulting in the formation of a stem cell niche.208 Following injury, damage, or normal cell attrition, stem cells within the niche receive signals resulting in transition to an active state and initiation of the differentiation process.209 Therefore, in order for regeneration of damaged tissues to occur, resident stem cell pools must be activated and induced to differentiate into lineage specific cells.210 Such activation signals may be biochemical or mechanical in nature, and therefore may be affected by exposure to microgravity. Spaceflight exposure may result in premature aging of specific physiological systems, and loss of stem cell functions may contribute to the initial observed tissue degeneration but more importantly, may be linked to regenerative deficits during long-duration spaceflight exposure beyond LEO.
Biomechanical performance design of joint prosthesis for medical rehabilitation via generative structure optimization
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
Jinghua Xu, Kang Wang, Mingyu Gao, Zhengxin Tu, Shuyou Zhang, Jianrong Tan
Most basic medical research concerning artificial joint prosthesis focus on material science, biomechanics and histological properties. Biological regeneration of the extremities can occur in some organisms (starfish, for example), but humans need recourse to a mechanical solution (Kotz et al. 2000). Myoelectric signals (MES) have been used in various applications, in particular, for identification of user intention to potentially control assistive devices for amputees, orthotic devices, and exoskeleton in order to augment capability of the user (Geethanjali 2016). Koizumi et al. (2016) designed cellular lattice structures with high strength and low Young’s modulus for artificial hip joints. Cengiz et al. (2016) developed patient-specific implants from patients' volumetric knee magnetic resonance imaging (MRI) datasets. Flesher et al. (2016) proposed that intracortical microstimulation of the somatosensory cortex offers the potential for creating a sensory neuroprosthesis to restore tactile sensation. Liverani et al. (2016) presented a study of Cobalt–Chromium–Molybdenum endoprosthetic ankle implant fabrication by means of metal 3 D printing. de Souza Batista et al. (2017) and Prochor and Sajewicz (2018) estimated long-term functionality of implants by a finite element analysis. Toti et al. (2018) evaluated the occurrence of complications and the degree of bone loss in a cohort of patients treated with fixed prostheses supported by immediately loaded dental implants. Liu et al. (2020) proposed the personalized osteotomy guide plate and prosthesis based on 3 D printing technique facilitate joint-preserving tumor resection and functional reconstruction. Total knee arthroplasty (TKA) is presently considered to be the most effective and successful treatment for end-stage or severe knee lesions.