Hybrid magnetic nanocomposites of arginine deiminase with improved stability and recyclability for biomedical applications.

Nanocarrier-based immobilization has created new avenues for enhancing the biophysical properties of enzymes. Nanomatrices such as magnetite nanoparticles (MNPs), chitin, and chitosan with large surface areas and tunable morphology have been developed to circumvent the bottlenecks of free enzymes. The present study used MNPs to immobilize the enzyme arginine deiminase (ADI) for improved morphological control, recovery, operational stability, and easy recyclability. Hybrid magnetic arginine deiminase cross-linked enzyme aggregate (mADI-CLEA) was developed for the first time by co-aggregating ADI with magnetite nanocomposites, followed by its cross-linkage with glutaraldehyde. Structural analysis by DLS/ZETA, SEM, and FT-IR revealed their highly stable and robust nature. The resulting mADI-CLEA exhibited higher pH resistivity and thermostability than ADI-CLEA. Reusability and storage stability assay indicated that mADI-CLEA maintained more than 60% residual activity even after seven batch cycles and was stable for more than 70 days. These hybrid magnetic aggregates of ADI offer an economical and stable alternative for biomedical applications of ADI.