In vitro magnetosome remineralization for silver-magnetite hybrid magnetosome biosynthesis and used for healing of the infected wound

Abstract

Background Magnetosomes (BMPs) are organelles of magnetotactic bacteria (MTB) that are responsible for mineralizing iron to form magnetite. In addition, BMP is an ideal biomaterial that is widely used in bio- and nano-technological applications, such as drug delivery, tumor detection and therapy, and immunodetection. The use of BMPs to create multifunctional nanocomposites would further expand the range of their applications. Results In this study, we firstly demonstrate that the extracted BMP can remineralize in vitro when it is exposed to AgNO3 solution, the silver ions (Ag+) were transported into the BMP biomembrane (MM) and mineralized into a silver crystal on one crystal plane of Fe3O4. Resulting in the rapid synthesis of an Ag-Fe3O4 hybrid BMP (BMP-Ag). The synergy between the biomembrane, Fe3O4 crystal, and unmineralized iron enabled the remineralization of BMPs at an Ag+ concentration ≥ 1.0 mg mL−1. The BMP-Ag displayed good biocompatibility and antibacterial activity. At a concentration of 2.0 mg/mL, the BMP-Ag and biomembrane removed Ag-Fe3O4 NPs inhibited the growth of gram-negative and gram-positive bacteria. Thus using BMP-Ag as a wound dressing can effectively enhance the contraction of infected wounds. Conclusions This study represents the first successful attempt to remineralize organelles ex vivo, realizing the biosynthesis of hybrid BMP and providing an important advancement in the synthesis technology of multifunctional biological nanocomposites. Graphical abstract

Large-Scale Cultivation of Magnetotactic Bacteria and the Optimism for Sustainable and Cheap Approaches in Nanotechnology

“…These cavities release mechanical energy that physically disintegrates cell components. Ultrasonic crushing has been applied in different works for BMN isolation [ 3 , 79 ]. However, the scalability of this operation is difficult because of the high energy consumption [ 78 ] and occupational inconvenience involved, as the sound waves released can damage audition without proper protective equipment.…”

“…Notably, under metal-rich environments, bacterial growth can be greatly hindered, highlighting the importance of understanding the growth of the metabolism of MTB considering their application in bioremediation. Recently, it was shown that purified BMNs also can incorporate metals within their membranes [ 79 ]. The ability to re-mineralize and incorporate metals into the BMN crystal may be useful for bioremediation purposes and generate BMNs with different compositions and features.…”

“…The ability to re-mineralize and incorporate metals into the BMN crystal may be useful for bioremediation purposes and generate BMNs with different compositions and features. For example, hybrid silver-magnetite BMNs were obtained by incubating Ag+ with purified BMNs; the hybrid Janus-like nanoparticle presented both BMN and silver nanoparticle characteristics [ 79 ].…”

Strategy for Avoiding Alicyclobacillus acidocaldarius Contamination of Apple Juice by Adding Magnetosomes/Antibacterial Peptide Composites

“…These issues could be potentially addressed through the replacement of magnetic nanomaterials with magnetotactic bacteria, which are gram-negative bacteria that correlate their directional movement with the direction of an applied magnetic field. Currently, among the 11 magnetotactic bacteria that have been isolated and purified, of which Magnetospirillum gryphiswaldense MSR-1 is the most studied as a model strain. − Magnetotactic bacteria have the ability to absorb iron ions in the environment and accumulate these ions as magnetite (Fe 3 O 4 ), pyropyrite (F 3 S 4 ), or tetragonal pyrite (FeS) crystal particles in prokaryotic organelles denoted as magnetosomes (MN), which are coated with lipid bilayer membranes or biofilms in the bacteria cells . Of particular importance in the current context is that, compared with the chemically synthesized magnetic nanoparticles, the MN are small, uniform, difficult to aggregate, and nontoxic.…”

“…Of particular importance in the current context is that, compared with the chemically synthesized magnetic nanoparticles, the MN are small, uniform, difficult to aggregate, and nontoxic. Most importantly, the biofilms on the surfaces of MN include a large number of bioactive groups, such as amino, carboxyl, free fatty acids, sugars, and phospholipids, that can be used as targets for connecting with selected compounds, thereby facilitating the modification of MN with various antibodies, enzymes, nucleic acids, chemotherapy drugs, and metal ions. − As a result, MN have been widely used in tumor chemotherapy, drug delivery, and immunoassay applications. ,− However, MN have rarely been considered for use in food.…”