International Journal of Pharmaceutics 288 (2005) 131–140 A chemical method of gentamicin bonding to gelatine-sealed prosthetic vascular grafts Gra˙ zyna Ginalska a,∗ , Dorota Kowalczuk b , Monika Osi ´ nska a a Department of Biochemistry, Maria Curie-Sklodowska University, 20-031 Lublin, Poland b Departmentof Medicinal Chemistry, Medical University, 20-093 Lublin, Poland Received 21 February 2004; received in revised form 7 September 2004; accepted 25 September 2004 Available online 18 November 2004 Abstract Our aim was to develop a new method of chemical binding of gentamicin to vascular prostheses made of poly(ethylene terephthalate) (PET) fibres and covered with pig gelatine. We estimated (with the HPLC method) the immobilization yield, which equalled 76 or 8% depending on the concentration of the antibiotic used and the amount of gentamicin bound to the prosthesis (1.08–20.6 mg/g of prosthesis). The antibiotic was coupled in two modes: stable covalent binding or weak adhesion. The results confirmed that only a small quantity of the antibiotic (1.03–3.09%) was bound by adsorption. The modification of the prosthesis surface with immobilized gentamicin was visualized with a scanning microscope (SEM). Bacteriostatic properties of bound gentamicin were verified against different concentrations (cfu) of Escherichia coli, Pseudomonas aeruginosa and Staphylococcusaureus strains. We have found lack of growth of these pathogen strains in Luria–Bertani (LB) medium containing pieces of gentamicin-coupled prosthesis during at least 28 days of the experiment. Contrary to that, a control medium containing pieces of prosthesis only soaked with gentamicin allowed a constant growth of bacteria. © 2004 Elsevier B.V. All rights reserved. Keywords: Biomaterial; Poly(ethylene terephthalate); Covalent immobilization; Antibacterial capabilities; SEM 1. Introduction Infections of vascular grafts occur despite full steril- ity during surgical procedures and regardless of peri- ∗ Corresponding author. Tel.: +48 81 5375666; fax: +48 81 5375761. E-mail address: ginal@hermes.umcs.lublin.pl (Gra˙ zyna Ginalska). operative parenteral antibiotic prophylaxis. Such infec- tions may cause a significant danger by increasing the risk of a patient’s death. The most common reason for infections is the presence of such bacterial strains as Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa and Pro- teus sp. (Huebner and Golabmann, 1999; Lyczak et al., 2000; Puzova et al., 1994). To prevent the coloniza- tion of biomaterial after implantation, graft surfaces 0378-5173/$ – see front matter © 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.ijpharm.2004.09.021