Biocompatible mesoporous silica particles for enzyme immobilization: A review

Enzyme immobilization within mesoporous silica is a powerful strategy for improving biocatalyst stability, reusability, and process economics in industrial applications. Conventional mesoporous silica materials, such as MCM-41 and SBA-15, possess high surface area, tunable pore size, and excellent thermal stability; however, their synthesis typically relies on surfactant templates and harsh calcination procedures that are incompatible with fragile biomolecules and sustainable manufacturing. In contrast, biocompatible mesoporous silica prepared through non-surfactant templating employs mild extraction conditions compatible with one-pot enzyme immobilization and direct hydrogel coating. The properties of biocompatible mesoporous silica particles (BMSP) can be further enhanced through surface engineering using silane coupling agents, crosslinking chemistry, and silanol density enhancement to improve enzyme–support interactions and immobilization efficiency. Hybrid architectures incorporating magnetic materials, organic polymers, carbonaceous supports, metal oxides, and hierarchical pore networks further expand BMSP functionality by enabling catalyst recovery, enhanced biocompatibility, improved structural robustness, and superior mass transport. However, these engineering strategies may also introduce diffusion limitations, enzyme conformational changes, and additional material and processing burdens that can significantly affect biocatalytic performance and environmental sustainability. This review systematically examines the structure–performance relationships associated with these challenges and evaluates the environmental implications of non-surfactant synthesis, surface functionalization, and hybrid material integration. Mitigation strategies, including larger non-surfactant templates, hierarchical meso-macroporous architectures, and optimized surface functionalization, are discussed to alleviate diffusion limitations and preserve enzyme structure. Quantitative descriptors, including the Thiele modulus, effectiveness factor, Michaelis constant (Km), and maximum reaction rate (Vmax), are highlighted as engineering tools for evaluating support performance and guiding rational materials design. This review provides a framework for developing next-generation biocompatible mesoporous silica platforms for sustainable industrial biocatalysis.