Abstract
Effective enzyme stabilization through immobilization is essential for the functional usage of enzymatic reactions. We propose a new method for synthesizing elastic hydroxyapatite microgel (E-HAp-M) materials and immobilizing lipase using this mesoporous mineral via the ship-in-a-bottle-neck strategy. The physicochemical parameters of E-HAp-M were thoroughly studied, revealing that E-HAp-M provides efficient space for enzyme immobilization. As a model enzyme, lipase (LP) was entrapped and then cross-linked enzyme structure, preventing leaching from mesopores, resulting in highly active and stable LP/E-HAp-M composites. By comparing LP activity under different temperature and pH conditions, it was observed that the cross-linked LP exhibited improved thermal stability and pH resistance compared to the free enzyme. In addition, they demonstrated a 156% increase in catalytic activity compared with free LP in hydrolysis reactions at room temperature. The immobilized LP maintained 45% of its initial activity after 10 cycles of recycling and remained stable for over 160 days. This report presents the first demonstration of a stabilized cross-linked LP in E-HAp-M, suggesting its potential application in enzyme-catalyzed processes within biocatalysis technology.