Superhydrophilic and tribological improvements of polymeric surfaces via plasma enhanced chemical vapor deposition ceramic coatings.

The main object of this study is the treatment of polymeric (PVC, PC) surfaces with the aim of inducing enhanced superhydrophilic characteristics together with nanohardness features; this would allow polymeric surfaces to have longer durability and prevent the accumulation of dirt on the surface which could disable the proper use of these polymeric surfaces. Indeed plastic surfaces are difficult substrates to be covered effectively and functionalized, mainly due to their high sensitivity to heat treatments and irradiation in the UV-Vis range together with their inert behavior. Their functionalization is achieved through the deposition of ceramic coatings such as titania (TiO2), on the polymeric surfaces via PECVD (Plasma Enhanced Chemical Vapor Deposition) at low temperatures. Characterizations are carried out by contact angle analysis for the superhydrophilic characteristics, and by nanoindentation analysis for the tribological features. A cold PECVD discontinuous method allowed us to improve nanohardness, reaching a value of 1.39 GPa which is nearly ten times higher than that of the uncoated polymeric substrate, and seems a promising solution for improving uniformity of the coatings. Superhydrophilic behavior of the activated TiO2 surfaces showed contact angle values lower than 10 degrees.

Immunological properties of a radioiodinated monoclonal antibody and its F(ab')2mu fragments directed against the polymorphic epithelial mucin of human breast cancer.

The purification of the IgM monoclonal antibody 436 against a breast tumor antigen from mouse ascitic fluid is reported. The purified immunoglobulin was radioiodinated and the resulting product assessed for its binding capacity and binding specificity. Purified IgM-436 served for F(ab')2 mu preparation which was tested for its antigen binding capacity. Radioiodinated IgM-436 and its F(ab')2 mu retained their immunological activity which was never lower than those of the corresponding cold products.

Distribution of SP1, immunoreactivity among different plasma proteins: real molecular heterogeneity or adsorption of SP1-beta to other plasma proteins?

Three SP1-containing factors from pooled term pregnancy sera were subjected to crossed immunoelectrophoresis. New patterns as far as electrophoretic mobilities and shapes of the immunoprecipitates were revealed. The appearance of an additional anodic radioimmunoassayable activity in agarose electrophoresis of mixed SP1-alpha and SP1-beta suggested a binding capacity of SP1-alpha for SP1-beta determinants. In the serum of a single patient at the third trimester of pregnancy we also found two SP1 variants, possessing little radioimmunological reactivity and with crossed immunoelectrophoretic characteristics quite different from those of the 'usual' alpha and beta SP1 forms. These results suggest that, in this particular case, the overall SP1 production cannot be evaluated by competitive binding assay and, that in general, SP1 is a complex antigen the heterogeneity of which can be determined following adsorption of some beta epitopes to another serum protein.