To prepared fluorescent chitosan capsules by in situ polyelectrolyte coacervation on poly(methacrylic acid)-doped porous calcium carbonate microparticles

Abstract

To prepare hollow microcapsules composed of native chitosan (CS), a templating method is developed using poly(methacrylic acid) (PMAA)-doped porous calcium carbonate (CaCO 3 ) microparticles as sacrificial templates. At first, CS was adsorbed onto PMAA-doped porous CaCO 3 microparticles, and then the adsorbed CS was covalently cross-linked with each other by using glutaraldehyde. After the dissolution of the templates, the resultant CS capsules ranged from 2 to 5 lm in diameter. Nitrogen adsorption-desorption analysis are applied to characterize the porous CaCO 3 templates, the BET surface area and total pore volume are 160 and 0.50 cm 3 /g. The structure and morphology of the CS capsules are characterized by FESEM and TEM. Confocal laser scanning microscopy images reveal that the capsules have been labeled with green FITC. The gradual capsule invagination in response to bulk osmotic pressure created by CS solutions has also been discussed.

Controlling the Vaterite CaCO3 Crystal Pores. Design of Tailor-Made Polymer Based Microcapsules by Hard Templating

“…This should first of all include the templated particles containing bioactive molecules due to mild decomposition conditions as a significant advantage of the CaCO 3 crystals for hard templating. Coprecipitation or cosynthesis approach − may also be considered for control over the crystal porosity by addition of the molecules of interest during crystal preparation. This would allow one to both include the molecules into the crystals and adjust crystal pore size at the same time.…”

“…Encapsulation of various biomolecules including small drugs and large biomacromolecules by CaCO 3 templating is a simple two-step process . First, the biomolecules are immobilized in the pores of the CaCO 3 crystals, accomplished by physical adsorption, ,− chemical cross-linking, − coprecipitation, − and trapping by coating with polyelectrolyte multilayers. ,,− The second step includes subsequent crystal dissolution (pH below neutral or EDTA) resulting in the formation of the microparticles with encapsulated biomolecules. A crucial step in the encapsulation is immobilization of molecules, because that determines the loading efficiency.…”

The Characterization and Amoxicillin Adsorption Activity of Mesopore CaCO3 Microparticles Prepared Using Rape Flower Pollen

“…An imposing specific surface area, good biocompatibility and non-toxic are the obvious features of porous calcium carbonate. Therefore, porous calcium carbonate is widely applied into all walks of life, such as drug carriers [2][3][4], bioceramics [5,6], biomicrocapsules [7,8], biosensors [9], bone repair [10], biomimetic mineralization [6,11], and so on. Generally, material structures and crystal forms, affected strongly by preparation and operation conditions, have rather significant effects on their application.…”

Spherical and Porous Particles of Calcium Carbonate Synthesized with Food Friendly Polymer Additives

“…Porous calcium carbonates are highly promising for applications in catalysis and biomedicine . This promise and the intriguing mechanisms of biomineralization of calcium carbonate have inspired several recent research efforts devoted to the synthesis of porous calcium carbonates − as well as using such calcium carbonates to induce porosity in solid polymers and proteins. − In general, porous calcium carbonates consist of aggregates of small particles of calcium carbonate. Hence, their porosity is interparticle based and controlled by the size and arrangement of the underlying nanoparticles within the aggregates.…”