Antioxidative protection of haemoglobin microparticles (HbMPs) by PolyDopamine

Abstract

Clinically applicable haemoglobin-based oxygen carriers (HBOCs) should neither induce immunological nor toxic reactions. Additionally, Hb should be protected against oxidation. In the absence of protective enzymes (superoxide dismutase (SOD) and catalase (CAT)) Hb is oxidized to MetHb and thus losing its function of oxygen delivery. Alternatively, polydopamine (PD), a scavenger of free radicals, could be used for Hb protection against oxidation Therefore, we synthetized HbMPs modified with PD. The content of functional haemoglobin in these PD-HbMPs was twice higher than that in the control HbMPs due to the protective antioxidant effect of PD. In addition, the PD-HbMPs exhibited a high scavenging activity of free radicals including H 2 O 2 and excellent biocompatibility. In contrast to monomeric dopamine, which has been shown to produce toxic effects on neurons due to formation of H 2 O 2 , hydroxyl radicals and superoxide during the process of auto-oxidation, PD-HbMPs are not neurotoxic. Consequently, the results presented here suggest a great potential of PD-HbMPs as HBOCs.

Fabrication and Characterization of Human Serum Albumin Particles Loaded with Non-Sericin Extract Obtained from Silk Cocoon as a Carrier System for Hydrophobic Substances

“…NS-HSA MPs exhibited a submicron size ranging from 0.8 to 0.9 µm with a negative zeta potential. The values of the zeta potential of the particles were different depending on the ionic strength of the suspension media such as those composed of water, PBS buffer, and 0.9% NaCl [33]. In accordance with this observation, the size and zeta potential of NS-HSA MPs were not significantly different from the empty HS-MPs when measured in PBS buffer.…”

“…Moreover, the establishment of a hemoglobin particle was modified and embedded with polydopamine, which was also identified in the submicron size. The particles displayed excellent biocompati-bility and were capable of protecting against the cytotoxic effects that can be caused by polydopamine substances [33]. The size of NS-HSA MPs was investigated by CLSM images.…”

Low‐Fouling Electrosprayed Hemoglobin Nanoparticles with Antioxidant Protection as Promising Oxygen Carriers

“…PDA has scarcely any chemical reaction with Hb's functional groups while also allowing for post‐functionalization (e.g., PEGylation) by its ability to react via Schiff base and/or Michael addition with thiols and amines . Furthermore, PDA can also offer antioxidant protection thus minimizing the conversion of Hb into nonfunctional metHb …”

“…Prior to PEGylation, the Hb‐NPs are coated with polydopamine (PDA), which is an effective adhesive material that can spontaneously form a continuous coating layer on a wide variety of surfaces . Furthermore, PDA has antioxidant properties which are crucial to minimize the conversion of Hb into nonfunctional methemoglobin (metHb) . Additionally, PEGylation of the Hb‐NPs (Hb/PEG‐NPs) is easily achievable by reaction of the PDA coating with the amino groups of the poly‐ l ‐lysine‐ graft ‐PEG (PLL‐ g ‐PEG) copolymer.…”

Surface Modification of Hemoglobin-Based Oxygen Carriers Reduces Recognition by Haptoglobin, Immunoglobulin, and Hemoglobin Antibodies

“…All samples were measured at the absorption spectra at wavelength 574 nm using a UV-vis spectrophotometer (Hitachi U2800, Hitachi High-Technologies Corporation, Tokyo, Japan), and an average of three individual measurements were recorded for calculation of the Hb concentration. The ferricyanide method was applied for measurement of the oxygen content on the surface-modified HbMPs [28,29]. Briefly, 2% (v/v) particle suspensions was placed into a glass vial containing a magnetic stirrer.…”