Magnetically controlled protein nanocontainers as a drug depot for the hemostatic agent.

Purpose: Currently, there is a number of successfully implemented local hemostatic agents for external bleedings in forms of wound dressings and other topical materials. However, little has been done in the field of intravenous hemostatic agents. Here, we propose a new procedure to fabricate biocompatible protein nanocontainers (NCs) for intravenous injection allowing magneto-controllable delivery and short-term release of the hemostatic agent ε-aminocaproic acid (EACA).

Methods: The nanocontainers were synthesized by the desolvation method from bovine serum albumin (BSA) using methanol without any further crosslinking. Polyethylene glycol (PEG) was used both as a stabilization agent and for size control. Characterization of nanocontainers was performed by the transmission and scanning electron microscopy, dynamic light scattering, X-ray diffraction, and FTIR spectroscopy. Cytotoxicity was estimated using MTT assay. The dopant release from nanocontainers was measured spectrophotometrically using rhodamine B as a model molecule. The specific hemostatic activity was assessed by analyzing clot lysis and formation curve (CloFAL). Moreover, the ability for magneto targeting was estimated using the original flow setup made of a syringe pump and silicon contours.

Results: Fabricated nanocontainers had an average size of 186±24 nm and were constructed from building blocks-nanoparticles with average size ranged from 10 to 20 nm. PEG shell was also observed around nanocontainers with thickness 5-10 nm. NCs were proved to be completely non-cytotoxic even at concentrations up to 8 mg BSA/mL. Uptake capacity was near 36% while release within the first day was 17%. The analysis of the CloFAL curve showed the ability of NCs to inhibit the clot lysis successfully, and the ability of magneto targeting was confirmed under flow conditions.

Conclusion: The ability of synthesized NCs to deliver and release the therapeutic drug, as well as to accumulate at the desired site under the action of the magnetic field was proved experimentally.