The biocompatibility and antibacterial properties of collagen-stabilized, photochemically prepared silver nanoparticles

EMILIO I. ALARCON; KLAS UDEKWU; MARTEN SKOG; NATALIA L. PACIONI; KEVIN G. STAMPLECOSKIE; MARIA GONZALEZ-BEJAR; NARESH POLISETTI; ABENI WICKHAM; AGNETA RICHTER-DAHLFORS; MAY GRIFFITH; JUAN C. SCAIANO

BIOMATERIALS

ELSEVIER SCI LTD

Año: 2012 p. 4947 - 4956

0142-9612

Spherical 3.5 nm diameter silver nanoparticles (AgNP) stabilized in type I collagen (AgNP@collagen) were prepared in minutes (5e15 min) at room temperature by a photochemical method initiated by UVA irradiation of a water-soluble non-toxic benzoin. This biocomposite was examined to evaluate its biocompatibility and its anti-bacterial properties and showed remarkable properties. Thus, while keratinocytes and fibroblasts were not affected by AgNP@collagen, it was bactericidal against Bacillus megateriumand E. coli but only bacteriostatic against S. epidermidis. In particular, the bactericidal properties displayed by AgNP@collagen were proven to be due to AgNP in AgNP@collagen, rather than to released silver ions, since equimolar concentrations of Ag are about four times less active than AgNP@collagen based on total Ag content. This new biocomposite was stable over a remarkable range of NaCl, phosphate, and 2-(N-morpholino)ethanesulfonic acid concentrations and for over one month at 4C. Circular dichroism studies show that the conformation of collagen in AgNP@collagen remains intact. Finally, we have compared the properties of AgNP@collagen with a similar biocomposite prepared using a-poly-LLysine and also with citrate stabilized AgNP; neither of these materials showed comparable biocompatibility, stability, or anti-bacterial activity.