Synthesis and bioactivity of chemotactic tetrapeptides: fMLF-OMe analogues incorporating spacer aminoacids at the lateral positions.

none5A small library of N-For and N-Boc tetrapeptidic analogues of the chemotactic tripeptide For-Met-Leu-Phe-OMe (fMLF-OMe), obtained by incorporating three different spacer aminoacids (Gly, betaAla and Pro) between the native residues of Met and Leu (N-For- and N-Boc-Met-Xaa-Leu-Phe-OMe; Xaa(2) series) and Leu and Phe (N-For- and N-Boc-Met-Leu-Xaa-Phe-OMe; Xaa(3) series), have been synthesized and examined for their biological activity as agonists and antagonists. Chemotaxis, lysozyme release and superoxide anion production have been measured. All the N-For analogues maintain good to moderate chemotactic activity with the betaAla(3) 15 model reaching the maximum value. All the N-Boc tetrapeptides are efficient chemotactic antagonists. Conversely, with the exception of the moderate antagonistic activity exhibited by the N-Boc Xaa(2) models against lysozyme release, all the other N-Boc analogues do not show significant activity against both superoxide anion and lysozyme release.noneG. Lucente; C. Giordano; A. Sansone; D. Torini; S. SpisaniG., Lucente; C., Giordano; A., Sansone; D., Torini; Spisani, Susann

Formation of Pegylated Polyurethane and Lysine-Coated Polyurea Nanoparticles Obtained from O/W Nano-emulsions

The present work describes the formation of Pegylated polyurethane and Lysine-coated polyurea nanoparticles obtained from O/W nano-emulsions via an interfacial polycondensation process in the aqueous solution/polysorbate 80/diisocyanate/medium chain triglyceride systems. The initial nano-emulsions were prepared using the phase inversion composition (PIC) method. Dynamic light scattering studies revealed the changes in the particle size occurring during the process of nanoparticle formation. Well-defined polymeric nanoparticles with a small particle diameter (below 80 nm) and low polydispersity index were obtained using a highly hydrophilic component (polyethylene glycol or lysine) and an aliphatic diisocyante monomer. FT-IR and AFM studies showed that the polymeric matrix of nanoparticles was built by copolymers derived from reaction between the diisocyanate and the hydroxyl groups of both nonionic surfactant and the highly hydrophilic component. Pegylated-polyurethane and lysine-coated polyurea nanoparticles designed in this study are promising tools for future applications in biomedical sciences.The authors acknowledge financial support by the Spanish Ministry of Education and Science, DGI (CTQ 2008-06892-C03-02/PPQ), “Generalitat de Catalunya” DURSI (Grant 2009 SGR-961), and CIBER-BBN. CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008–2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fundation.Peer reviewe