Figure 1.

Illustration of α-gal nanoparticles. (A) Suggested functions of α-gal nanoparticles in wounds. The α-gal nanoparticle comprises phospholipids and α-gal glycolipids, each capped with an α-gal epitope (α-GAL in rectangles). When α-gal nanoparticles are applied to wounds, their α-gal epitopes bind the natural anti-Gal antibody, resulting in activation of the complement system (step #1). The produced chemotactic complement cleavage peptides induce rapid recruitment of macrophages (step #2). Anti-Gal coating the α-gal nanoparticles further interacts through its Fc tail with Fcγ receptors (FcR) on macrophages (step #3). This interaction activates macrophages to produce and secrete a variety of cytokines that accelerate wound healing (step #4). (B) Binding of anti-Gal-coated α-gal nanoparticles to macrophages as a result of Fc/FcR interaction (step #3 in Fig. 1A), as evaluated by scanning electron microscopy. (C) Enlargement of the inset in (B). The surface of a representative macrophage is covered with α-gal nanoparticles. The size of the α-gal nanoparticles is ∼100–300 nm (modified from Ref.²⁷).