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Cellular Biology in Tissue Engineering
Published in Joseph W. Freeman, Debabrata Banerjee, Building Tissues, 2018
Joseph W. Freeman, Debabrata Banerjee
When discussing stimulatory influences, it is almost impossible to avoid the subject of bone composition. Bone is a very dynamic material, it can break down or build up based on the metabolic requirements of our body. Usually, growth factors and hormones are the ones responsible for these catabolic/anabolic processes. However, there are many external stimulatory influences that are designed to try to mimic the physiological actions of the body. For example, therapeutic ultrasound has been used as a healing technique to treat bone fractures and avoid invasive procedures.92 Studies have shown that ultrasound therapy has successfully been able to promote regeneration and bio-absorption.93,94 It can treat bone defects by emitting mechanical frequencies that are above the threshold of human hearing. Ultrasound (US) therapy has been used for many years and has now become an essential tool in the clinic. High-intensity US can damage tissues; therefore, low-intensity pulsed ultrasound (LIPUS) is generally used in the clinic.
Medical Applications
Published in Suresh C. Ameta, Rakshit Ameta, Garima Ameta, Sonochemistry, 2018
Veronick et al. (2016) studied the effect of low-intensity pulsed ultrasound (LIPUS) to help in bone fracture repair and to treat non-union defects. Ultrasound was also evaluated as a means of generating a transdermal physical force that could initiate osteoblasts that had been encapsulated within collagen hydrogels and led to bony defects. It was also shown that ultrasound generates a physical force and when applied to hydrogel, results in their deformation. The effect became intense as ultrasound intensity was increased and hydrogel stiffness was reduced.
Application of electrospun nanofibers in bone, cartilage and osteochondral tissue engineering
Published in Journal of Biomaterials Science, Polymer Edition, 2020
Huixiu Ding, Yizhu Cheng, Xiaolian Niu, Yinchun Hu
Low-intensity pulsed ultrasound (LIPUS) is a physical stimulation method used to treat osteoarthritis. Studies have found that LIPUS can affect various types of cells involved in bone healing, which can affect cell metabolism to a certain extent, thereby improving the cell survival microenvironment, increasing cell nutrition, and further achieving the purpose of promoting bone repair. Chen et al. proposed a multi-layer integrated scaffold bionic structure design containing cartilage calcification layer [126]. Sodium alginate (SA)/CS hydrogel was used as cartilage layer, and after compounding with micron hydroxyapatite (μmHA) was the cartilage calcification layer; the lower layer was the SA/HA composite parallel channel scaffold; the cell partition membrane prepared by the electrospinning technology in the middle was used as the interface barrier layer, and different growth factors were respectively loaded (Figure 9(A)). The results showed that the integrated scaffold composite system had good binding properties, and the bone scaffold layer exhibited a parallel pore structure. The composite scaffold was implanted into the rabbit bone cartilage defect. After 12 weeks, the subchondral bone in the composite growth factor + LIPUS group was almost completely reconstructed into normal cancellous bone, and the new cartilage was no different from normal cartilage (Figure 9(B)).
Prevention and repair of orthodontically induced root resorption using ultrasound: a scoping review
Published in Expert Review of Medical Devices, 2023
Mahmoud Sedky Adly, Afnan Sedky Adly, Richard Younes, Marwan El Helou, Ivan Panayotov, Frederic Cuisinier, Delphine Carayon, Elias Estephan
Regarding the intensity of ultrasound, studies reported that low intensity pulsed ultrasound (30–150 mW/cm2) has the ability to stimulate osteoblasts and inhibit root resorption. In addition, it may cause inhibition of osteoclastogenesis with long-term exposure [32]. The intensity of 30–150 mW/cm2 is commonly recommended due to its anabolic biophysical effects on numerous cell type in vitro studies [25,29]. The reparative effect of 150 mW/cm2 US is reported to be effective because of its anabolic effects on cementoblasts. However, it can cause fibrosis of the dental pulp cells [22]. Another study found that this intensity can impair TNF-α signaling in vitro and reduce trauma-related root resorption and it can also improve collagen synthesis [36]. It was revealed that ultrasound stimulation of 30 mW/cm2 improved the healing process of orthodontically induced root resorption in humans. In contrast, an intensity of 150 mW/cm2 was more effective in alkaline phosphatase transcription and calcium content upregulation [32]. Therapeutic ultrasounds of 1 to 3 W/cm2 intensities can produce a significant thermal reaction in the living tissues. These intensities demonstrated anti-inflammatory effects around the roots, and enhanced bone protein expression and growth factors stimulation [30]. It was also found that a quantitative relationship was present between ultrasound intensity and thicknesses of regenerated cementum, since greater cementum thickness was observed in areas of the root which received higher power and vice versa [19]. There was a heterogeneity of intensities found in the literature concerning root resorption; however, our findings demonstrated that the most commonly used intensity was 30 mW/cm2 which was reported to be effective in all of the studies except for one study that utilized only a single-dose application. On the other hand, studies with tooth movement acceleration as a main motive tend to use higher intensities such as 100 and 300 mW/cm2 [25].