International Journal of Pharmaceutics, 41 (1988) 181-187 Elsevier 181 IJP 01383 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Research Papers Sorptive properties of antibodies onto cyanoacrylic nanoparticles C. Kubiak ‘, L. Manil 2 and P. Couvreur 1 ’ Laboratoire de Pharmacie Galhnique et de Biopharmacie, UA CNRS 1218, UniuersitP de Pans-Sud, Ch&enay - M alabry (France) and ’ D&partement de Biologic Clinique et Unit6 de Mkdecine Nuckaire, Institut Gustave-Roussy, Villejuif (France) (Received 31 March 1987) (Accepted 30 June 1987) Key words: Cyanoacrylic nanoparticle; Monoclonal antibody; Immunoradiometric assay; Targeting; Immunonanoparticle Summary Further studies were carried out on the interaction of monoclonal antibodies (MAbs) with cyanoacrylic nanoparticles (NP). Even after incubation in culture media with set-k proteins, these immunoparticles conserved a good immunoreactivity and a sufficient stability for potential usefulness in targeting. On the other hand, optima1 conditions were determined for using these NP as a solid phase for immunoassays. More surprisingly, it was observed that radiolabelling of monoclonal antibodies with iodine induced important changes in the physicochemical interaction between the protein and the polymeric support. Introduction Cyanoacrylic nanoparticles (NP) were firstly designed as a lysosomotropic and biodegradable drug carrier (Couvreur et al., 1979a and b; Lenaerts et al., 1984). However, the major uptake of these particles by the reticuloendothelial system (mainly liver and spleen) could be a drawback for cancer targeting. An increased uptake by the tumoural cells might be obtained after coating the surface of NP with monoclonal antibodies against tumour- associated antigens. In a preliminary paper (Manil et al., 1986a), we demonstrated the feasibility of the preparation of such immunoparticles which, in addition, were efficient for the immunoradio- metric assay (IRMA) of tumoural markers such as a-fetoprotein (AFP). Parameters useful for im- Correspondence: P. Couvreur, Laboratoire de Pharmacie Galenique et de Biopharmacie, UA CNRS 1218, Universite de Paris-Sud, F92290 Chltenay-Malabry, France. proving both the immunoreactivity and the stabil- ity of these conjugates, however, had not been tested. Therefore, the present study describes methodological improvements able to optimize the efficiency of NP-IRMA and the stability of MAb- NP binding. Furthermore, owing to the disappointing results obtained in the in vivo targeting with such carriers (Illum et al., 1984) we investigated the interaction of NP with MAb in seric conditions in particular, with special attention to the bioerosion of the polymer, potentially responsible for a quick re- lease of the antibody. Materials and Methods Chemicals and monoclonal antibodies (MAbs) Isobutylcyanoacrylate (IBC) and isohexylcya- noacrylate (IHC) monomers were obtained from Ethnor (Paris, France) and Weil Chemische Fabrik 0378-5173/88/$03.50 0 1988 Elsevier Science Publishers B.V. (Biomedical Division)