Chemokine (C-X-C motif) ligand 1 (CXCL1) and chemokine (C-X-C motif) ligand 2 (CXCL2) modulate the activity of TRPV1+/IB4+ cultured rat dorsal root ganglia neurons upon short-term and acute application.

CXCL1 and CXCL2 are two chemokines with 78% homology of their sequence. CXCL1 was associated with atopic dermatitis, a highly pruritic skin disease, but it is not clear what is its mechanism of action, while for CXCL2 there are no data about an association with itch sensitivity. CXCL1 and CXCL2 can modulate TRPV1 receptors, which are one of the most important downstream effectors for itch sensitivity, upon short-term (4 h) or long-term (24 h) incubation, but the data are incomplete. Therefore, the aims of this study were to better characterize the short-term effects of CXCL1 and CXCL2 on TRPV1+/IB4+ dorsal root ganglia neurons known to include nociceptor and itch-sensitive neurons, and to obtain new data about the acute application (12 min) of the two chemokines on the same population of neurons. The results showed that 4 nM CXCL1 and 3.6 nM CXCL2 significantly reduce TRPV1 desensitization in TRPV1+/IB4+ DRG +neurons after short-term incubation, but when acutely applied CXCL1 activated a sub-population of itch-sensitive TRPV1+/IB4+ cells in a slow, low amplitude manner, while CXCL2 had a similar effect but on non-itch TRPV1+/IB4+ DRG neurons. These data contribute to a better understanding of CXCL1 and CXCL2 mechanism of action for both pain and itch inducing effects.

Laser deposition of poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) - lysozyme microspheres based coatings with anti-microbial properties.

The purpose of this study was to obtain, characterize and evaluate the cytotoxicity and antimicrobial activity of coatings based on poly(3-hydroxybutyric acid-co-3-hydroxyvaleric acid) - Lysozyme (P(3HB-3HV)/Lys) and P(3HB-3HV) - Polyethylene glycol - Lysozyme (P(3HB-3HV)/PEG/Lys) spheres prepared by Matrix Assisted Pulsed Laser Evaporation (MAPLE) technique, in order to obtain functional and improved Ti-based implants. Morphological investigation of the coatings by Infrared Microscopy (IRM) and SEM revealed that the average diameter of P(3HB-3HV)/Lys spheres is around 2µm and unlike the drop cast samples, IRM recorded on MAPLE films revealed a good distribution of monitored functional groups on the entire scanned surface. The biological evaluation of MAPLE structured surfaces revealed an improved biocompatibility with respect to osteoblasts and endothelial cells as compared with Ti substrates and an enhanced anti-biofilm effect against Gram positive (Staphylococcus aureus) and Gram negative (Pseudomonas aeruginosa) tested strains. Thus, we propose that the fabricated P(3HB-3HV)/PEG/Lys and P(3HB-3HV)/Lys microspheres may be efficiently used as a matrix for controlled local drug delivery, with practical applications in developing improved medical surfaces for the reduction of implant-associated infections.