Search

In the search for new biotechnological advances, increasing attention is currently being paid to the development of magnetic nanoplatforms loaded with enzymes, since, on the one hand, they can be recovered and reused, and on the other hand, they improve their catalytic activity and increase their stability, avoiding processes such as aggregation or autolysis. In this review, we evaluate a series of key parameters governing the enzyme–nanoparticle immobilization phenomena from a thermodynamic and kinetic point of view. We also focus on the use of magnetite nanoparticles (MNPs) as multifunctional vectors able to anchor enzymes, summarize the most relevant aspects of functionalization and immobilization and, finally, describe some recent and relevant applications of the enzyme–MNP hybrids as biocatalysts with especial emphasis on cancer therapy.

This study was supported by projects RTI-2018-095794-A-C22, RYC-2016-21042 and project PID2020-118498GB-I00 funded by MCIN/AEI/10.13039/501100011033 and projects P18-FR-3533 and P18-TP-0969 by FEDER/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades (Spain). Thanks go to the CIC personnel of the University of Granada for technical assistance. MCMT acknowledges grant PRE2018-083773 funded by MCIN/AEI/10.13039/501100011033 and FSE "El FSE invierte en tu futuro", Spain. GBRR also acknowledges Junta de Andalucia for her postdoctoral contract within the PAIDI 2020 program ( DOC_01383)., Self-assembled peptides and proteins have turned out to be excellent templates for the growth of inorganic minerals and can be used to emulate natural biomineralization processes. Doing this, researchers have developed complex sophisticated materials with properties, in some cases, similar to those found in nature. Of special interest is the development of scaffolds able to guide bone regeneration. The bone tissue comprises an organic matrix composed of aligned collagen fibers containing nanoapatite crystals oriented along the fiber direction. During bone mineralization, both processes, the self-assembly of collagen fibrils and mineralization occur simultaneously. Collagen fibers are able to control calcium phosphate nucleation and subsequent apatite crystal growth at a very limited range of collagen density and ionic concentration. In this study, we reproduced the simultaneity of both processes using an artificial peptide fluorenylmethoxycarbonyl-diphenylalanine (Fmoc-FF) that has the ability to self-assemble in water after the addition of Ca2+ ions. Therefore, the peptide self-assembly process and the mineralization of apatite are Ca-demanding processes and occur simultaneously. The role of peptide and ionic concentrations has been investigated affording organic/inorganic hybrid hydrogels with different degrees of homogeneity and mineralization. Interestingly, at very low Ca2+ concentrations, we found that apatite nanocrystals are integrated into Fmoc-FF fibrils and oriented as in biologically mineralized collagen fibrils, the basic building blocks of bone., FEDER/Junta de Andalucia-Consejeria de Transformacion Economica, Industria, Conocimiento y Universidades (Spain) P18-FR-3533 P18-TP-0969, FSE "El FSE invierte en tu futuro", Spain, Junta de Andalucia DOC_01383; RTI-2018-095794-A-C22; RYC-2016-21042; PID2020-118498GB-I00; MCIN/AEI/10.13039/501100011033; PRE2018-083773