Immobilization of fibrinolytic protease from Mucor subtilissimus UCP 1262 in magnetic nanoparticles.

This work reports the immobilization of a fibrinolytic protease (FP) from Mucor subtilissimus UCP 1262 on Fe3O4 magnetic nanoparticles (MNPs) produced by precipitation of FeCl3·6H2O and FeCl2·4H2O, coated with polyaniline and activated with glutaraldehyde. The FP was obtained by solid state fermentation, precipitated with 40-60% ammonium sulfate, and purified by DEAE-Sephadex A50 ion exchange chromatography. The FP immobilization procedure allowed for an enzyme retention of 52.13%. The fibrinolytic protease immobilized on magnetic nanoparticles (MNPs/FP) maintained more than 60% of activity at a temperature of 40 to 60 °C and at pH 7 to 10, when compared to the non-immobilized enzyme. MNPs and MNPs/FP did not show any cytotoxicity against HEK-293 and J774A.1 cells. MNPs/FP was not hemolytic and reduced the hemolysis induced by MNPs from 2.07% to 1.37%. Thrombus degradation by MNPs/FP demonstrated that the immobilization process guaranteed the thrombolytic activity of the enzyme. MNPs/FP showed a total degradation of the γ chain of human fibrinogen within 90 min. These results suggest that MNPs/FP may be used as an alternative strategy to treat cardiovascular diseases with a targeted release through an external magnetic field.

Fucoidan-Coated Liposomes: A Target System to Deliver the Antimicrobial Drug Usnic Acid to Macrophages Infected with Mycobacterium tuberculosis.

The present study describes the use of fucoidan, a negative sulfated polysaccharide, as a coating material for the development of liposomes targeted to macrophages infected with Mycobacterium tuberculosis. First, fucoidan was chemically modified to obtain a hydrophobized-fucoidan derivative (cholesteryl-fucoidan) using a two-step microwave-assisted (µW) method. The total reaction time was decreased from 14 hours to 1 hour while maintaining the overall yield. Cholesterylfucoidan was then used to prepare surface-modified liposomes containing usnic acid (UA-LipoFuc), an antimicrobial lichen derivative. UA-LipoFuc was evaluated for mean particle size, polydispersity index (PDI), surface charge (ζ), and UA encapsulation efficiency. In addition, a cytotoxicity study, competition assay and an evaluation of antimycobacterial activity against macrophages infected with M. tuberculosis (H37Ra) were performed. When the amount of fucoidan was increased (from 5 to 20 mg), vesicle size increased (from 168 ± 2.82 nm to 1.18 ± 0.01 µm). Changes in from +20 ± 0.41 mV for uncoated liposomes to -5.41 ± 0.23 mV for UA-LipoFuc suggested that the fucoidan was placed on the surface of the liposomes. UA-LipoFuc exhibited a lower IC50 (8.26 ± 1.11 µM) than uncoated liposomes (18.37 ± 3.34 µM), probably due to its higher uptake. UA-LipoFuc5 was internalized through the C-type carbohydrate recognition domain of the cell membrane. Finally, usnic acid, both in its free form and encapsulated in fucoidan-coated liposomes (UA-LipoFuc5), was effective against infected macrophages. Hence, this preliminary investigation suggests that encapsulated usnic acid will aid in further studies related to infected macrophages and may be a potential option for tuberculosis treatment.

Pharmaceutical nanotechnology: which products are been designed against COVID-19?

The current pandemic COVID-19, caused by the SARS-CoV-2 virus, has been affecting thousands of people worldwide, promoting high numbers of deaths. With this, the world population is going through a process of changing habits, with social distance, improvement of hygiene techniques, to reduce the spread of the SARS-CoV-2 virus and, consequently, reduce the number of hospitalized people in serious condition, as well as the mortality rate. This scenario has been promoting a continuous search for researchers, in the most varied areas, for possible methods of prevention or cure. Specifically, in the field of pharmaceutical nanotechnology, a variety of products are being developed against SARS-CoV-2. Under these circumstances, we propose here an exposition of some of the nanotechnological products (nanoscale between 1 to 1000 nm) currently designed for the detection of the virus, for the prevention and treatment of COVID-19, in addition to equipment for personal protection. We believe that pharmaceutical nanotechnology will be a valuable tool in the disease from the development of products that guarantee our protection against the SARS-CoV-2 virus.