Hydroxyapatite (HA) has been widely used as a scaffold in tissue engineering. HA possesses high mechanical stress and exhibits particularly excellent biocompatibility owing to its similarity to natural bone. Nonetheless, this ceramic scaffold has limited applications due to its apparent brittleness. Therefore, this had presented some difficulties when shaping implants out of HA and for sustaining a high mechanical load. Fortunately, these drawbacks can be improved by combining HA with other biomaterials. Starch was heavily considered for biomedical device applications in favor of its low cost, wide availability, and biocompatibility properties that complement HA. This review provides an insight into starch/HA composites used in the fabrication of bone tissue scaffolds and numerous factors that influence the scaffold properties. Moreover, an alternative characterization of scaffolds via dielectric and free space measurement as a potential contactless and nondestructive measurement method is also highlighted.
The mineral composition, crystallinity, and dielectric properties of salts can provide valuable insights into the quality and suitability of different types of salt for various applications. In this study, comprehensive analysis of the X-Ray Diffraction (XRD), X-ray fluorescence (XRF) and dielectric analysis of the Ba'kelalan salt, Himalaya salt and Bamboo salt have been investigated. The mineral composition of these salts, encompassing vital elements such as iodine and other trace minerals, significantly influences the salt's nutritional profile and overall excellence. Nonetheless, gauging the dispersion and density of these minerals poses difficulties due to conventional techniques that can be arduous, damaging, and expensive. Sample preparation is carried out before conducting X-ray diffraction (XRD), X-ray fluorescence (XRF), and dielectric analysis. XRD measurements are performed using the Bruker D2 Phaser to identify crystalline material phases. XRD operates on the principle of constructive X-ray interference within crystalline samples. For elemental analysis across a broad spectrum of materials, XRF is employed. Elemental peaks are scanned, starting from the lowest to the highest angle of incidence. The X-ray intensity at characteristic peaks is compared to the standard series. Dielectric spectroscopy analysis examines the dielectric behaviour of Ba'kelalan salt, Himalaya salt, and Bamboo salt. The setup involves a vector network analyser (VNA) paired with an open-ended coaxial probe, utilizing the microwave method. This approach ensures rapid, efficient, and non-destructive measurements of dielectric constants (ε') and loss factors (ε"). The dielectric permittivity spectra are acquired within the frequency range of 4 GHz-20 GHz. ε' of these salts increase with frequency. Meanwhile, ε" seem varies insignificantly over frequency. Mineral contents and crystallinity are the crucial factors lead to these responses. Based on the study, the quality and suitability of the selected salts for specific applications can be determined by considering their mineral composition, crystallinity, and dielectric properties in the context of the intended use. This gives an insight for some applications that may benefit from certain minerals or crystalline structures, others may require specific dielectric properties for effective use. Therefore, understanding these properties allows for decision-making in choosing the right type of salt for a given purpose, whether it's for foods, medical, industrial, healthcare, and technological applications.