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Reduction and Fixation of Sacroiliac joint Dislocation by the Combined Use of S1 Pedicle Screws and an Iliac Rod
Published in Kai-Uwe Lewandrowski, Donald L. Wise, Debra J. Trantolo, Michael J. Yaszemski, Augustus A. White, Advances in Spinal Fusion, 2003
Kai-Uwe Lewandrowski, Donald L. Wise, Debra J. Trantolo, Michael J. Yaszemski, Augustus A. White
The term fibroblast growth factor encompasses a group of nine polypeptides that share an affinity for cellular glycosaminoglycan heparin-binding sites [106]. FGFs are secreted by macrophages, mesenchymal cells, chondrocytes, and osteoblasts and act as mitogens on a variety of cellular phenotypes, such as epithelial cells, myocytes, chondrocytes, and osteoblasts via their interaction with a tyrosine kinase receptor [107]. Among FGFs, two types are found in adult human tissues: acid FGF (a-FGF or FGF-1) and basic FGF ((3-FGF or FGF-2), which have been shown to be involved in chondrocyte and osteoblast proliferation, respectively [108,109]. Since experimental research has indicated that FGFs can accelerate bone healing, their clinical application as bone-healing enhancers may be hypothesized [101]. IGFs
Marine Biopolymers
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Bone fractures are caused mainly by diseases, trauma, or accident. For treatment of bone defects, the normal therapies such as autograft bone, allograft bone, and xenograft bone are used. However, these treatments have disadvantages such as more chance for infections, reaction of the immune system, and limits in availability. Bone healing is a complicated process that requires mechanical stability and revascularization along with osteoinduction, osteoconduction, and osseointegaration. Scaffolds made by calcium-alginate showed the ability to facilitate the growth and differentiation of human osteoblast cell clusters with maintained cell viability, up-regulated bone-related gene expression, and biological apatite crystals formation (Chen et al., 2015). The bone substitute should be the appropriate scaffold for promoting the osteoconductivity (bone grows on a surface), containing the growth factors to enhancing the osteoinductivity (the stimulation of the immature cells to develop into preosteoblasts), and making the matrix for osseointegration (Albrektsson & Johansson, 2001). Alginate by itself can not satisfy all the requirements of the bone substitute; therefore, it must be combined with other compounds such as calcium silicate, calcium phosphate, hydroxyapatite, and other polymers such as collagen, gelatin, and chitosan. Sathain et al. examined the properties of the scaffold made from alginate, carrageenan, and calcium silicate. The scaffolds showed good mechanic properties, nontoxicity to human living cells, and proper diclofenac release from the scaffold, promoting the formation of hydroxyapatite in the surface of scaffold that is suitable for the treatment of acute inflammation after surgery (Sathain et al., 2021).
Two-Dimensional Nanomaterials for Drug Delivery in Regenerative Medicine
Published in Harishkumar Madhyastha, Durgesh Nandini Chauhan, Nanopharmaceuticals in Regenerative Medicine, 2022
Zahra Mohammadpour, Seyed Morteza Naghib
Clay-based biomaterials have presented numerous opportunities for constructing bioactive cell-laden scaffolds for efficient repair of bone defects. Besides, due to their high loading capacity, clays are excellent choices for loading bone-forming factors, including BMP-2. Clinical studies have displayed the ability of BMP-2 in eliciting bone formation. To exert the high efficiency of this therapeutic protein, precise and prolonged delivery is of high importance. Laponite, a layered nanosilicate-based platform, has attracted a myriad of interests in bone reformation (Prabha et al. 2019). Apart from its high loading capacity, previous studies have shown that the leakage of silicate and lithium ions from the Laponite nanostructures enhances cell spreading on substrates, upregulates the expression of osteogenic genes, and induces the production of mineralised matrix (Xavier et al. 2015). Driven by such properties, Zhang et al. explored the co-delivery of nanosilicates and growth factors from a 3D hydrogel scaffold for osteoinduction (Zhang et al. 2020e). They synthesised hydrogels consisting of HA and dextran through Schiff base chemistry. They introduced Laponite@BMP-2 complexes into the hydrogel matrix. The synergistic effect of simultaneous delivery of Laponite nanoplatelets and BMP-2 was evaluated. The proliferation rates of stem cells incubated with Laponite and Laponite@BMP-2 complexes were higher than that of BMP-2 alone. Also, the ALP relative activity of the cells that were incubated with Laponite@BMP-2 complexes was markedly upregulated compared with Laponite or BMP-2, which was ascribed to the synergistic effects of both the released ions from the Laponite structure and the sustained release of BMP-2. Evaluation of the protein release kinetics showed that bare hydrogel completely released BMP-2 during the first week, the mechanism of which was probably dominated by diffusion. In case of Laponite-containing hydrogels, the release time prolonged to four weeks. In the next step, for evaluating the in vivo osteogenic capacity of the modified hydrogel, stem cells were loaded into hydrogel and injected into the defective region of a rat calvarial defect model. After eight weeks post-operation, the μ-CT scan revealed that the defective site that was cured by hydrogel/Laponite@BMP-2 was almost completely covered by the new bone. The results of this study revealed that pragmatic challenges associated with direct administration of BMP-2 including fast clearance and very short half-life can be avoided by employing bioactive clay-based scaffolds. In a similar study, Laponite in combination with gelatin and alginate were used for the fabrication of an injectable hydrogel, the composition of which was similar to ECM (Liu et al. 2020). Hydrogels were loaded with stem cells and injected into a bone defective rat model. A significant accelerated bone healing was achieved.
Design considerations for piezocomposite materials for electrical stimulation in medical implants
Published in Journal of Medical Engineering & Technology, 2022
Ember Krech, Evan Haas, Grace Tideman, Bonnie Reinsch, Elizabeth Friis
Non-union and delayed bone healing from orthopaedic procedures are common complications for many patients causing pain, discomfort and increased time and cost to return to normal activities of daily living [1,2]. Nonunions develop in large gap healing scenarios, most commonly in spinal fusion procedures and long bone fracture fixation procedures where implant stabilisation is necessary to encourage natural bone regeneration [3,4]. However, for 10–30% of patients, the risk of improper, delayed bone healing is a costly outcome [5]. To supplement bone healing and improve fracture and surgical fusion success rates, several adjunct therapies are used in addition to the primary implants. Electrical stimulation has successfully been used clinically for decades in both spinal fusion and long bone fracture healing to stimulate healthy bone growth and enhance fusion success, significantly reducing risk for non-union [6–11]. The most widely used modality is direct current (DC) electrical stimulation [10], increasing overall fusion rates and showing exceptional results in difficult-to-fuse populations, especially tobacco users and high-risk patients [8,10,12,13]. Current implantable DC electrical stimulation devices require additional surgery to place and remove subcutaneous battery packs, limiting widespread clinical adoption even with evidence of enhanced gap healing [8,14,15].
Enhancing the bone healing on electrical stimuli through the dental implant
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
Letícia Bins-Ely, Daniela Suzuki, Ricardo Magini, Cesar A. M. Benfatti, Wim Teughels, Bruno Henriques, Júlio C. M. Souza
The balanced electrical stimuli on titanium implants has some advantages regarding the cell migration, angiogenesis, and bone growth. The fundamentals on the electrical stimuli are related to the electrochemical reactions around the implant. On the direct electrical stimuli, the titanium implant becomes a cathode while the bone and the surrounding tissues are the anode. Then, the electrical current flows around the implants through the surrounding medium leading to the formation of hydroxyl radical that increase the pH (Bodamyali et al. 1999). As a result, the low oxygen content and the alkaline environment stimulate the activity of osteogenic cells and therefore the hydrogen peroxide content stimulates the release of vascular endothelial growth factors (VEGF) (Song et al. 2009). The continuous electrical stimuli at a well-controlled magnitude can regulate the osteoinductive growth factors, such as bone morphogenetic proteins (BMP-2, 6, and 7), which stimulates the cellular proliferation, differentiation, and extracellular matrix synthesis (Fredericks et al. 2007). That can enhance the bone growth by contact and distance osteogenesis processes within a bone healing speed-up (Fredericks et al. 2007).
The application of nanogenerators and piezoelectricity in osteogenesis
Published in Science and Technology of Advanced Materials, 2019
Fu-Cheng Kao, Ping-Yeh Chiu, Tsung-Ting Tsai, Zong-Hong Lin
However, some fracture healings can not be treated with rigidly stable managements, as most fractures need to be treated with bracing that involves some degree of motion, including cast immobilization, intramedullary nails, bridge plating, and external fixation devices. Therefore, primary bone healing is rare, and the majority of fracture healing proceeds via secondary bone healing, or endochondral ossification, which occurs via a cartilage callus. There are four major phases of secondary bone healing, which include the inflammatory phase, early callus phase, mature callus phase, and remodeling phase. The inflammatory phase is characterized by an acute bone marrow response, post-damaged inflammation, and hematoma formation immediately following the fracture and up to 3–4 days after (Figure 2(a)). The damaged tissue releases proinflammatory mediators, such as interleukin 1 (IL-1), IL-6, and tumor necrosis factor alpha (TNF-α), to initiate the repair process [20]. The second stage is the early callus phase. This phase is predominated by soft cartilage callus formation, angiogenesis, and chondrogenesis at the fracture gap [21] (Figure 2(b)). Subsequently, the cartilaginous matrix is mineralized to begin the third phase, the mature callus phase. At this point, the chondrocytes undergo apoptosis and osteoblasts infiltrate the callus. The primary bone is laid down on these surfaces [22] (Figure 2(c)). In the last phase or remodeling phase, the newly formed woven bone is progressively replaced by mature lamellar bone, ultimately restoring the original cortical structure [23] (Figure 2(d)).