<p>A Protein Corona Adsorbed to a Bacterial Magnetosome Affects Its Cellular Uptake</p>

Abstract

It is well known that when exposed to human blood plasma, nanoparticles are predominantly coated by a layer of proteins, forming a corona that will mediate the subsequent cell interactions. Magnetosomes are protein-rich membrane nanoparticles which are synthesized by magnetic bacteria; these have gained a lot of attention owing to their unique magnetic and biochemical characteristics. Nevertheless, whether bacterial magnetosomes have a corona after interacting with the plasma, and how such a corona affects nanoparticle-cell interactions is yet to be elucidated. The aim of this study was to characterize corona formation around a bacterial magnetosome and to assess the functional consequences. Methods: Magnetosomes were isolated from the magnetotactic bacteria, M. gryphiswaldense (MSR-1). Size, morphology, and zeta potential were measured by transmission electron microscopy and dynamic light scattering. A quantitative characterization of plasma corona proteins was performed using LC-MS/MS. Protein absorption was further examined by circular dichroism and the effect of the corona on cellular uptake was investigated by microscopy and spectroscopy. Results: Various serum proteins were found to be selectively adsorbed on the surface of the bacterial magnetosomes following plasma exposure, forming a corona. Compared to the pristine magnetosomes, the acquired corona promoted efficient cellular uptake by human vascular endothelial cells. Using a protein-interaction prediction method, we identified cell surface receptors that could potentially associate with abundant corona components. Of these, one abundant corona protein, ApoE, may be responsible for internalization of the magnetosome-corona complex through LDL receptor-mediated internalization. Conclusion: Our findings provide clues as to the physiological response to magnetosomes and also reveal the corona composition of this membrane-coated nanomaterial after exposure to blood plasma.

Harnessing the Protein Corona towards Surface Design for Nanoparticle Tumor Delivery

“…The external boundary of BMPs is a biomembrane, and the large amounts of functional groups on surface proteins and lipids [13] facilitates chemical and genetic engineering. In the present study, BMPs adsorbed ~ 200 µg IgGs per mg, in contrast to 1.5 µg proteins per mg of iron oxide NPs in a previous study [37] .…”

“…Coronas of BMPs have not been analyzed until last year [37] . We developed and describe here a simple alternative design strategy for directed formation of NP protein corona.…”

Indian Herb-Derived Phytoconstituent-Based Antiviral, Antimicrobial and Antifungal Formulation: An Oral Rinse Candidate for Oral Hygiene and the Potential Prevention of COVID-19 Outbreaks

“…Total flavonoid content in the herbal extract was measured using the Aluminum chloride method (15). Briefly, 50 µL of herbal extract was homogenously mixed with 100 µL of 2% AlCl 3 , and the reaction mixture was incubated in darkness for 1 hour at room temperature.…”

“…For decades, common human coronaviruses (HCoVs) have circulated in the human population without any significant mortality [ 2 , 3 , 4 , 5 , 6 , 7 ]. However, in less than 20 years, three new HCoVs have emerged, causing severe respiratory syndromes and significant mortality [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ]. Several viral infections have created serious threats in the last two decades, claiming thousands of human lives.…”

“…The major method of transmission of SARS-CoV-2 is through aerosolized respiratory droplets. Some of the most common symptoms of COVID-19, such as coughing and sneezing, are associated with the formation of aerosols [ 15 , 19 ]. Persons infected but showing only mild or no symptoms (asymptomatic infection) can readily spread the virus through aerosols [ 15 , 19 , 26 , 27 ].…”