Influence of Calcification Solution on in vitro Chitosan Mineralization

Abstract

The influence of the calcification solution on the mineralization of chitosan membranes was analysed. Two factors were studied: pH and chemical composition (excess of calcium or phosphate ions) of solutions. Substrates (membranes) of chitosan underwent mineralization by soaking in calcification solutions for 7 days at 36.5 °C. As expected, SEM-EDS analyses demonstrated that higher pH and concentration of ions increases deposition, however, the morphology and composition of these deposits varies depending on which ion (phosphate or calcium) is in excess. Larger spherical deposits are observed when a calcium-rich solution is used instead of a phosphate-rich one. In the latter, the interconnectivity of the inorganic and organic (matrix) phases is very different, suggesting a different mechanism of deposition for each situation

Chitosan membrane as a template for hydroxyapatite crystal growth in a model dual membrane diffusion system

“…Our results differ from the data obtained by other authors in experiments with the chitosan membranes, which after preparation by casting and coagulation in NaOH were soaked in body fluids-simulating solutions of pH 7.4 and 7.8 [20]. The morphology of CPP deposits on chitosan membranes thus obtained showed the formation of irregular sphere-shaped structures in contrast to the well-defined formation of HAP crystals under the dual membrane diffusion conditions.…”

“…These highly favourable biological and chemical properties make chitosan, hitherto underutilized, an attractive starting material for many diverse biomedical and biorelated applications [5][6][7]. Different forms of chitosan-based biomaterials have recently been developed for biomedical purposes, including scaffolds [8][9][10][11], nanocomposites [12][13][14], tubes [15], sponges [16], coatings [17], microspheres [18], wound dressings [19] and membranes [20,21], of which, notably, those combined with hydroxyapatite are especially useful for potential applications in bone repair and regeneration.…”

Self-Assembled Polyelectrolyte Nanocomplexes between Chitosan Derivatives and Insulin

“…As reported previously,21 at the physiological pH of 7.4 human insulin carries two negative charges per molecule. As for chitosan, the protonation of the molecule's amino groups can be represented by: 22 where α is the fraction of unprotonated free amino‐groups NH 2 . Since the pKa of chitosan is approximately 6.5, we can calculate the proportion of amino groups that are not positively charged based on the final system pH.…”

Electrochemically Active Mercury Nanodroplets Trapped in a Carbon Nanoparticle–Chitosan Matrix

“…Chitosan is a poly-aminosaccharide with good binding properties for both many metal ions (via coordination to the amine) and many anionic molecules (via electrostatic binding to ammonium at a pH lower than the chitosan pK a % 6.5 [27]). The binding properties of chitosan remain after formation of the mesoporous chitosan -carbon nanoparticle composite film and are exploited here for mercury adsorption [28].…”