Molecular properties of lysozyme-microbubbles: towards the protein and nucleic acid delivery

Abstract

Microbubbles (MBs) have specific acoustic properties that make them useful as contrast agents in ultrasound imaging. The use of the MBs in clinical practice led to the development of more sensitive imaging techniques both in cardiology and radiology. Protein-MBs are typically obtained by dispersing a gas phase in the protein solution and the protein deposited/cross-linked on the gas-liquid interface stabilizes the gas core. Innovative applications of protein-MBs prompt the investigation on the properties of MBs obtained using different proteins that are able to confer them specific properties and functionality. Recently, we have synthesized stable air-filled lysozyme-MBs (LysMBs) using high-intensity ultrasound-induced emulsification of a partly reduced lysozyme in aqueous solutions. The stability of LysMBs suspension allows for post-synthetic modification of MBs surface. In the present work, the protein folded state and the biodegradability property of LysMBs were investigated by limited proteolysis. Moreover, LysMBs were coated and functionalized with a number of biomacromolecules (proteins, polysaccharides, nucleic acids). Remarkably, LysMBs show a high DNA-binding ability and protective effects of the nucleic acids from nucleases and, further, the ability to transform the bacteria cells. These results highlight on the possibility of using LysMBs for delivery of proteins and nucleic acids in prophylactic and therapeutic applications.

Design of a Novel Composite H2S‐Releasing Hydrogel for Cardiac Tissue Repair

“…By calibration curves, the used concentrations of the mixture and the number of MBs and PHFMBs were estimated at 250.0 ± 32 × 10 6 mL –1 and 153.3 ± 40 × 10 8 mL –1 , respectively. Fluorescent MBs were obtained using an FITC conjugation protocol: 1 μL of 10 mg mL –1 fluorescein isothiocyanate (FITC, Sigma‐Aldrich, Italy) in DMSO solution was added to 100 μL of MBs (3 mg mL –1 of BSA) in 15 × 10 –3 m sodium bicarbonate, pH 8.0, buffer and the mixture incubated in dark condition for 2 h at room temperature, after washing with H 2 O dd the MBs were observed at fluorescence microscopy. No significant changes of the molar concentration of BSA of the MBs were observed at this molar concentration of buffer in the incubation time.…”

“…MBs were obtained by sonication of protein solutions combining two acoustic phenomena: emulsification and cavitation. MBs protect the coated proteins against the enzymatic digestion and prolong their release. Moreover, the presence of gas‐filled microbubbles within the scaffold structure increases the oxygen availability to enhance cell proliferation.…”

H2S-releasing nanoemulsions: a new formulation to inhibit tumor cells proliferation and improve tissue repair

“…FITC-BSA solution was obtained using an optimized FITC conjugation protocol [153, 154]. 1 μl of 10 mg/ml FITC in DMSO solution was added to 100 μl of NEs (with 3 mg/ml BSA) in 15 mM sodium bicarbonate, pH 8.0, buffer and the mixture incubated at room temperature for 2 h in dark condition.…”

Treatment effects of lysozyme-shelled microbubbles and ultrasound in inflammatory skin disease

“…Stable air-filled LY-shelled MBs were recently synthesized using high-intensity US-induced emulsification of partly reduced LY in aqueous solutions14. That study investigated the possibility of using LY-shelled MBs for delivering proteins and nucleic acids in prophylactic and therapeutic applications.…”