Effect of TGF-ß3 on wound healing of bone cell monolayer in static and hydrodynamic shear stress conditions.

Introduction: Wound healing is characterized as a complicated and sophisticated biological process through which tissue heals and repairs itself after injury. However, the normal wound healing process relies on different growth factors as well as the presence of an accurate cytokine level to ensure appropriate cellular responses. In the case of wound healing, the effects of various growth factors have been studied, but the effects of transforming growth factor beta (TGF-ß) on wound healing have been found to be more significant because of its broad spectrum of impacts on healing the wounded tissues or skins. Methods: In the current study, the impact of TGF-ß3 in bone cells' wound healing was examined in vitro. Furthermore, the activities and characteristics of TGF-ß3, as well as those of related growth factors throughout this wound healing process, were studied under hydrodynamic shear stress conditions as well as static conditions of cultured bone cells. Results: We demonstrated that a positive outcome of TGF-ß3 treatment was found after 24 h under a static condition, while TGF-ß3 treatment was found to be effective under a dynamic condition for wound closure. In the case of the dynamic condition, a full wound closure was obtained after 18 h in both the control and TGF-ß3 treatment, while in the case of static conditions, wounds were found to remain open, even after 24 h, for both the control and TGF-ß3 treatment. Additionally, in the static condition, the wound closure rate with TGF-ß3 treatment was found to be quicker than that of the control flask, which implies that wound healing can be postponed in the static condition. In the dynamic condition, the wound healing process became more rapid in a cultured cell environment. Conclusion: The synergistic effect of TGF-ß3 and hydrodynamic shear stress conditions had a positive impact on increasing wound healing and improving the rate of wound closure.

Applications and Life Cycle Assessment of Shape Memory Polyethylene Terephthalate in Concrete for Crack Closure.

Shape memory polymer (SMP) products have been developed for application as crack closure devices in concrete. They have been made from PET in the form of both fibres and hollow tubes. Here, manufacturing methods using die-drawing and mandrel-drawing to induce shape memory are reported. The fibre-based devices are incorporated into concrete and, upon triggering, exert shrinkage restraint forces that close cracks in the concrete. The evolution of shrinkage restraint force in the fibres as manufactured was measured as a function of temperature, showing stresses in excess of 35 MPa. Tendons consisting of fibre bundles are incorporated into concreate beams subjected to controlled cracking. When activated, the tendons reduce the crack widths by 80%. The same fibres are used to produce another class of device known as knotted fibres, which have knotted ends that act as anchor points when they incorporated directly into concrete. Upon activation within the cracked concrete, these devices are shown to completely close cracks. The tubes are used to enclose and restrain prestressed Kevlar fibres. When the tubes are triggered, they shrink and release the prestress force in the Kevlar, which is transferred to the surrounding concrete in the form of a compressive force, thereby closing cracks. The Kevlar fibres also provide substantial reinforcement after activation. The devices are shown to be able to partially and fully close cracks that have been opened to 0.3 mm and achieve post-activation flexural strengths comparable to those of conventional reinforced and prestressed structural elements. Finally, a preliminary life cycle assessment study was used to assess the carbon footprint a nominal unit of concrete made with SMPs fibres compared to conventional concrete.

Investigation of Plasma Treatment on Micro-Injection Moulded Microneedle for Drug Delivery.

Plasma technology has been widely used to increase the surface energy of the polymer surfaces for many industrial applications; in particular to increase in wettability. The present work was carried out to investigate how surface modification using plasma treatment modifies the surface energy of micro-injection moulded microneedles and its influence on drug delivery. Microneedles of polyether ether ketone and polycarbonate and have been manufactured using micro-injection moulding and samples from each production batch have been subsequently subjected to a range of plasma treatment. These samples were coated with bovine serum albumin to study the protein adsorption on these treated polymer surfaces. Sample surfaces structures, before and after treatment, were studied using atomic force microscope and surface energies have been obtained using contact angle measurement and calculated using the Owens-Wendt theory. Adsorption performance of bovine serum albumin and release kinetics for each sample set was assessed using a Franz diffusion cell. Results indicate that plasma treatment significantly increases the surface energy and roughness of the microneedles resulting in better adsorption and release of BSA.