Preparation of aminosilane–alginate hybrid microcapsules and their use for enzyme encapsulation

Abstract

Organic-inorganic hybrid microcapsules (AP-capsules) were fabricated by sequential preparation of calcium alginate microcapsules (Alg-capsules), followed by the addition of the Alg-capsules to an aqueous solution of 3-aminopropyltriethoxysilane (APTES) in mild conditions without the use of any catalyst. Results showed that the shell thickness of AP-capsules was found to vary with time during the APTES incorporation onto the Alg-capsules, suggesting that the shell thickness was dependent on the amount of CaCl 2 contained initially in the core solution as well as on the reaction time. A model enzyme, formate dehydrogenase (FDH), was successfully encapsulated in AP-capsules, and maximum efficiency of encapsulation was found with the capsule size of 1 mm diameter. The AP-capsules were reused efficiently for 10 cycles without loss of FDH activity. The approach developed in this study could evolve as a generic platform of enzyme immobilization for biotechnology applications using core-shell microcapsule technology.

One‐step preparation of organic‐inorganic hybrid capsules based on simultaneous gelation and silicification

“…EDX analysis confirmed the existence of Si (AAPTS) and calcium in the shell of AEA‐capsule (Figure F). Our previous studies, describing two‐step preparation method of alginate‐aminosilane hybrid capsules, have shown that soaking of Alg‐capsules in an aqueous solution containing aminopropyltriethoxysilane (APTES) induced gradual shrinkage of alginate shell along the thickness direction with time course and finally formed thin shell membrane with homogenous structure . The results of the morphological and EDX analyses were consistent with those obtained in the previous study.…”

“…Our previous studies, describing two-step preparation method of alginate-aminosilane hybrid capsules, have shown that soaking of Alg-capsules in an aqueous solution containing aminopropyltriethoxysilane (APTES) induced gradual shrinkage of alginate shell along the thickness direction with time course and finally formed thin shell membrane with homogenous structure. 23,24 The results of the morphological and EDX analyses were consistent with those obtained in the previous study. Therefore, these results suggested that AAPTS was successfully incorporated into alginate shell via an electrostatic interaction between positively charged amino groups of AAPTS and negatively charged carboxyl groups of alginate along with polycondensation of AAPTS.…”

Synthesis and characterization of a stable humic–urease complex: application to barley seed encapsulation for improving N uptake

“…The values of enzyme activity retained in the seed coating layer may be related to the coating process. Firstly, leakage of the enzyme can occur during the encapsulation process, probably before the alginate capsule was formed, which could result in a decrease in the calculated coating yield. Thus Vikartovská et al reported enzyme losses of about 56% during the first step of the encapsulation of glucose oxidase in polyelectrolyte complex capsules.…”

Thermostable α‐amylase immobilization: Enhanced stability and performance for starch biocatalysis

“…a. The use of alginate–enzyme immobilization has a good track record for biotechnological applications, which are listed in Table . Several studies have shown that immobilized enzymes are functionally active and can be reused up to several cycles.…”