إنشاء منظومة اللهب لتحضير طبقة متوافقة حيوياً من فوسفات الكالسيوم في الزوارع الطبية

Construction of the Flame Coating system for Preparing Biocompatible Layer of Calcium Phosphate Medical Implants

In this work, a biocompatible layer of calcium phosphite was prepared on stainless steel substrates and tested for use as medical implants with layers compatible with in human body. These coatings have shorten the healing period for bone building on the materials used. The flame coating system was built and designed. Also, the properties of the deposited films were controlled by several variables (the ratio between the components, the distance between the flame source and the bases), the examination of the deposited films using several techniques. X-ray diffraction (XRD), infrared spectroscopy (FTIR), field emission scanning electron microscopy (FE-SEM) , X-ray energy dispersive spectrometry (EDX), then testing the deposited layers by immersing them in a solution simulating the human body to monitor the growth of the Hydroxyapatite (HA) layers on the deposited films to study the antibacterial activity of the prepared layers.
In this research, layers of calcium phosphite with different ratios (1.4, 1.5, 1.65, 1.8, 1.9) and different distances from the flame nozzle (2,3,4,5,6 cm) were prepared using the flame coating process on the substrate at a distance of 3 cm from flame nozzle. XRD showed many peaks that match the crystal structure of calcium phosphate. Additional peaks for the stainless steel substrate appeared in all samples. There are small differences in the positions of the peaks due to lattice strain due to the variation in crystal size. It is also clear that the intensity of the peaks increased at the ratio 1.65 and the best at the distance of 3 cm. On the other hand, the width of the peaks for the same sample decreases indicating higher crystallization level and crystal size growth.
Infrared spectroscopic examinations(FTIR) showed that the samples contained carbonate ions with bands showing at 1412.42, 1082.69 and 805.81 cm-1 for the organic compounds of the which gas butane used in the deposition process. In addition, the hydroxide bands appeared in 3400, 1640.69, 6450.17 cm-1, which are identical to the water molecules adsorbed on the surface of the samples. It was demonstrated that the carbonate bands are of higher density compared to the phosphate bands indicating a high percentage of carbonates in all samples. Phosphate peaks were the most visible in the prepared sample with a ratio of 1.65 and a distance of 3 cm compared to the other samples.
Electron microscopy (FE-SEM) examination showed that the distinct and clear sample at the ratio of 1.65 and a distance of 3 cm, which has high porosity and contains distinct nanostructures.
The elements were analyzed using an energy-dispersive X-ray spectrometer (EDX) and the appearance of the basic elements for the synthesis of calcium phosphate. The samples were immersed in the body fluid simulating the human body to examine the biocompatibility, where the tests showed that the calcium phosphate ratio of 1.65 is the appropriate and biocompatible ratio in the human body. Tests showed antibacterial activity using diffusion disc technology. On the surface of the culture medium, was noticed the spread of Escherichia coli bacteria on the entire medium except for some areas around some samples.
The used method can be considered as a promising method to be used in coating medical implants in a simple way instead of the complicated traditional methods that require high technologies.