Treatment and Consolidation of Mummies and Human Remains with Bio-Natural Chitosan for Improving Antifungal, Antibacterial and Mechanical Strength Properties

Bio-natural chitosan solutions with different concentrations (1, 2, 3 wt., %) were investigated to coat weak bone remains to enhance their durability, mechanical, and antimicrobial characteristics, archaeological bones can be affected by various deterioration problems, resulting in changes in their chemical and physical characteristics. Numerous analyses were used to evaluate the used chitosan material such as X-ray fluorescence spectroscopy (XRF), Fourier Transform Infrared Spectroscopy (FTIR), viscosity, while the coated samples were evaluated using Scanning Electron Microscope (SEM), Bone Mineral Density (BMD), and antimicrobial. According to the results, the chemical composition of bio-natural chitosan possesses important trace elements like Sr, Mn, Zn, and Cu, which have beneficial antimicrobial properties. The particle size by number and zeta potential of chitosan particles ranges from 137.7 nm to 77.4, respectively. In addition, an observed increase in Vickers’s hardness value of about 10.9 % was detected, for samples treated with nano chitosan polymer up to 2 wt.%. On the contrary, when the concentration of chitosan solution was increased to 3 wt.%, Vickers's hardness value decreased as a result of the high viscosity of the solution. Natural chitosan polymer coating the bone remains resulted in a reduction in porosity and an increase in mineral density in the treated bone remnants. The study revealed a significant increase in the color difference (ΔE) value from 0.845 to 2.567 as the chitosan solution's contents increased from 1 to 3 wt.%. Furthermore, the thermal ageing time test for the more optimal sample (C2) resulted in a color difference of 1.546. Significant activity against G-positive and G-negative pathogenic bacteria, in addition to more resistant to various pathogenic fungi was observed in in vitro studies using nano-form chitosan on the treated samples compared to un-treated samples.