Chitosan/calcium—alginate beads for oral delivery of insulin

Abstract

A mild chitosan/calcium alginate microencapsulation process, as applied to encapsulation of biological macromolecules such as albumin and insulin, was investigated. The microcapsules were derived by adding dropwise a protein-containing sodium alginate mixture into a chitosan-CaC12 system. The beads containing a high concentration of entrapped bovine serum albumin (BSA) as more than 70% of the initial concentration were achieved via varying chitosan coat. It was observed that approximately 70% of the content is being released into Tris-HC1 buffer, pH 7.4 within 24 h and no significant release of BSA was observed during treatment with 0.1M HC1 pH 1.2 for 4 h. But the acid-treated beads had released almost all the entrapped protein into Tris-HC1 pH 7.4 media within 24 h. Instead of BSA, the insulin preload was found to be very low in the chitosan/calcium alginate system; the release characteristics were similar to that of BSA. From scanning electron microscopic studies, it appears that the chitosan modifies the alginate microspheres and subsequently the protein loading. The results indicate the possibility of modifying the formulation in order to obtain the desired controlled release of bioactive peptides (insulin), for a convenient gastrointestinal tract delivery system.

Chitosan coated alginate beads containing poly(N‐isopropylacrylamide) for dual‐stimuli‐responsive drug release

“…An increased load of other drugs in chitosan-coated alginate beads has also been reported. 18,19,23,30 It can also be noted from Table I that the chitosan concentration has little effect on the loading efficiency. So, the electrostatic interaction between chitosan and alginate tightens and stabilizes the surface of the beads.…”

Investigation of mechanical properties of soft hydrogel microcapsules in relation to protein delivery using a MEMS force sensor

“…The relatively inert aqueous environment inside the gel, a controllable gel porosity by coating with polycationic polymers (e.g., chitosan), and degradability under physiological conditions make alginate an excellent material for protein delivery. Alginate microcapsules have been studied for sustained release or immobilization of bioactive agents such as enzymes, 25 vaccine, 26 insulin, 27 and cytokines. 28,29 In a previous work by Liu et al, 22 an internal gelation-protein-adsorption-polyelectrolyte coating method was employed.…”

Synthesis of chitosan‐based thermo‐ and pH‐responsive porous nanoparticles by temperature‐dependent self‐assembly method and their application in drug release

“…[31][32][33][34][35][36][37][38] In the drug delivery field, chitosan and derivatives have been designed as carriers in various forms, such as film, gel, and microsphere for delivery of vaccines, DNA, and insulin. [39][40][41] In addition, chitosan also has pH-sensitive properties due to the protonation-deprotonation equilibrium of amino groups in chitosan. Therefore, chitosan is a smart environmental sensitive polymer.…”