Biomineralization of calcium carbonate by adding aspartic acid and lysozyme

Abstract

Calcium carbonate is one of the most abundant materials present in nature. Crystal structures of CaCO 3 become three polymorphic modifications, namely calcite, aragonite and vaterite. Polymorphic modifications are mediated by adding aspartic acid (Asp) and lysozyme. Lysozyme, which is a major component of egg white proteins, has influenced the calcification of avian eggshells. The influence of Asp and lysozyme on the crystallization of CaCO 3 was investigated by adding these additives and calcium chloride solution into sodium carbonate solution in a crystallization vessel. CaCO 3 crystals were analyzed by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and Fourier transform infrared spectrometry (FT-IR). XRD was used to select the intensities and crystal structure of specific calcium carbonate. SEM was employed for the analysis of the morphology of the precipitation and particle size. Two kinds of crystals were identified by FT-IR spectrum. Hexagonal crystals of vaterite were affected by the Asp in the crystallization solution. However, rhombohedral crystals of calcite by lysozyme were formed without any sign of vaterite. INTODUCTIONCaCO 3 crystal is essential to form the frame of an organism and has contributed to synthesis of nanomaterials. In biomineralization, calcium carbonate (CaCO 3 ) is one of the most abundant mineral resources formed in the natural environment. CaCO 3 has increasingly attracted interest and industrial demand has increased for several years on account of physical and chemical properties of CaCO 3 . Therefore, crystallization of calcium carbonate was extensively studied as it is widely used in the paper, paint, rubber and biomedical application [1]. The application of calcium carbonate particles is determined by several factors, such as particle morphology, specific surface area, particle size, particle size distribution [2]. Calcium carbonate exhibits three polymorphic modifications (rhombic calcite, needlelike aragonite and spherical vaterite) [1]. Crystal properties can be controlled by modifying the reaction medium using surfactants, suspensions, additives and precipitation conditions such as pH [3] and temperature. Calcite is usually formed at a high solution pH and low temperature, while vaterite and aragonite are formed at a low solution pH and high temperature. They are transformed to stable calcite since vaterite is unstable crystal morphology [4-6]. The ACC (amorphous calcium carbonate) forms in the initial stage of calcium carbonate reaction, and it is transformed into vaterite, aragonite and calcite [7-10].The gas-liquid reaction of CaCO 3 is that CO 2 gas is absorbed into calcium hydroxide solution. CaCl 2 -Na 2 CO 3 represents liquid-liquid reaction. The liquid-liquid reaction for CaCO 3 crystallization makes both CaCO 3 crystals and NaCl byproduct as Eq. (1) CaCl 2 (aq)+Na 2 CO 3 (aq)→CaCO 3 (sol)+2NaCl (byproduct) (1) This is because the reaction easily controls saturation concentration in solution and produces various morphologies of CaCO 3...

Protein-Mediated Precipitation of Calcium Carbonate

“…The data shown in Figure 2 c indicates that the addition of lysozyme had a weak influence on the morphological rhombohedral calcite. These data are in a good agreement with previous results [ 32 ]. This is due to the lysozyme possessing 18 positively-charged surface amino acids [ 12 ].…”

“…These data are in a good agreement with previous results [32]. This is due to the lysozyme possessing 18 positively-charged surface amino acids [12].…”

CaCO3 powder-mediated biomineralization of antigen nanosponges synergize with PD-1 blockade to potentiate anti-tumor immunity

“…3D,G), BANSs consisted of two CaCO 3 crystalline forms (calcite and aragonite) (Figs. 2D and 3D), whereas the crystalline form of CaCO 3 in OVA@CaCO 3 was vaterite phase as reported [7]; The CaCO 3 crystal structure was related to its stability, the CaCO 3 crystalline forms of calcite (triangles structure) and aragonite (rhombohedral crystal system) were stable under ambient conditions [13,21].…”

“…However, the integration of calcium adjuvants like Calcium carbonate (CaCO 3 ) is easy to lead to large particle sizes (~ 500 nm) [7], which are not favorable for lymph node transportation of vaccine and antigen crosspresentation. The underlying mechanism of the one-pot biomineralization method is probably associated with the fast kinetic reaction of Ca 2+ and CO 3 2− , leading to random and quick biomineralization [11][12][13]. In addition, the uncontrolled quick biomineralization tends to embed the antigen inside and thus adversely affects the exposure of antigen display.…”

Effect of Biomolecules on the Nanostructure and Nanomechanical Property of Calcium-Silicate-Hydrate

“…The three proteins studied were lysozyme, albumin, and hemoglobin. These proteins have been extensively studied for various applications including biomineralization of calcium carbonate 33 , synthesis of nanoparticles 34 , and synthesis of metal oxide nanocomposites and inorganic/organic hybrid materials 35 – 39 . The specifications of the proteins are given in Table 2 .…”