Magnetosome Modification: From Bio‐Nano Engineering Toward Nanomedicine

Abstract

Bacterial magnetosomes (MS) are one of the most intriguing paradigms for microbial production of iron crystals within a membrane vesicle by a biomineralization process with high degree of biological control in specific intracellular locations. The use of unique properties of MS has gained considerable interest in board applications, such as magneto immunoassays and biosensing, as well as drug delivery and biomedical imaging. The functionalization of these membrane and protein bound crystals of magnetic iron minerals is of great interest for the bioengineering and biomedical applications. Herein, an overview on bioengineering strategies to develop functionalized MS for better capabilities in diagnostic and therapeutic nanomedicine is presented. Specifically, the strategies in which MS could be functionalized by genetic and chemical modifications on the membrane, as well as the crystals modifications by the mineral concentration chages in culture medium are discussed. In addition, biomimetic generation of MS-like magnetic nanoparticles using the mechanisms of biomineralization in MS is also described. Finally, new perspectives and future directions for MS development in personalized and precision nanomedicine are discussed.

Microbe‐Mediated Extracellular and Intracellular Mineralization: Environmental, Industrial, and Biotechnological Applications

“…These custom‐tailored magnetosomes have been intensively investigated for MRI‐based detection of cancerous cells in experimental tumor models, [ 320–324 ] Bioengineering of MTB may be achieved using methods that include direct chemical modification, genetic engineering, and hybrid modification ( Figure A). With the advancement of nanotechnology, magnetosomes may be functionalized with different ligands such as enzymes, proteins, nucleic acids, green‐fluorescent protein, antibodies, and drugs (Figure 16B) [ 325 ] for multifunctional applications (Figure 16C). Among these applications, enhancement of imaging contrast is one of the best‐known examples.…”

“…A,B) Reproduced with permission. [ 325 ] Copyright 2018, Wiley‐VCH. C) Reproduced under the terms of the CC‐BY Creative Commons Attribution 4.0 International license ( http://creativecommons.org/licenses/by/4.0/).…”

Bioengineered Polyhydroxyalkanoates as Immobilized Enzyme Scaffolds for Industrial Applications

“…Meanwhile, the size and morphology of the magnetosomes are controlled by another set of magnetosome membrane proteins as, for example, MamC/Mms13, MamD, MamF, MamG, MamR, MamS, Mms6, and MmsF (Uebe and Schüler, 2016;Islam et al, 2018;Dieudonné et al, 2019). Interestingly, magnetosomes can be functionalized in vivo by fusing foreign proteins of interest to the magnetosome membrane proteins, such as MamC/Mms13, MagA, and Mms16 (Arakaki et al, 2008;Ren et al, 2018). The translational fusion of functional proteins to these transmembrane proteins of magnetosomes has led to numerous successful prototypes in a wide range of applications, including of industrial uses (Ginet et al, 2011;Sugamata et al, 2013;Honda et al, 2015a,b;Xiang et al, 2017;Mickoleit and Schüler, 2018).…”

“…The translational fusion of functional proteins to these transmembrane proteins of magnetosomes has led to numerous successful prototypes in a wide range of applications, including of industrial uses (Ginet et al, 2011;Sugamata et al, 2013;Honda et al, 2015a,b;Xiang et al, 2017;Mickoleit and Schüler, 2018). The inherent magnetic characteristics of magnetosomes make them very useful in some situations, especially for implementation in magneticfield-related technologies, such as magneto-immunoassays and biomedical imaging (Ren et al, 2018). The implementation of magnetosomes also allows rapid magnetic separation of the functionalized particulate scaffolds from the bulk fluids .…”

Photoacoustic reporter genes for noninvasive molecular imaging and theranostics

“…18,19 Therefore, PAI could be applied in various clinical¯elds such as primary tumor detection, therapeutic monitoring, molecular characterization of cancer, metastatic lymph nodes assessment, etc. 14,[20][21][22][23][24][25] As the fastest-growing molecular imaging technique, many e®orts have been made to improve the PAI technologies to achieve better resolution and sensitivity over the past two decades, [26][27][28][29][30] especially with various PA probes being extensively developed for high contrast images. [31][32][33] The ideal PA probes need to exhibit the characteristics such as with strong absorption in the near-infrared optical window, high speci¯city and stability in vivo, good targeting and biocompatibility, easy labeling, low°uorescence quantum yield, no need for exogenous substances, etc.…”