No abstract

Fourier transform (FT) Raman spectroscopy has been proved to be an adequate technique for the study of the quantitative structural changes which take place in poly(ethy1ene terephthalate) on annealing. The two-phase conformational model proposed previously in the infrared domain using photoacoustic FTIR has been extended to the Raman domain. Moreover, typical Raman spectral changes with the thermal process have been directly related to conformational rather than crystallinity changes. The correlation between the percentage of the trans isomer obtained by FT-Raman and skin layer crystallinity values obtained by differential scanning calorimetry allows the crystalline and amorphous trans isomer contents to be obtained and their evolution with the annealing process to be followed.

Elastin-like recombinamer click gels (ELR-CGs) for biomedical applications, such as drug delivery or tissue engineering, have been developed by taking advantage of the click reaction (CuAAC) in the absence of traditional crosslinking agents. ELRs are functionalized with alkyne and azide groups using conventional chemical techniques to introduce the reactivity required to carry out the 1,3-dipolar cycloaddition under mild biocompatible conditions, with no toxic by-products and in short reaction times. Hydrogels with moduli in the range 1,000-10,000 Pa have been synthesized, characterized, and tested in vitro against several cell types. The cells embedded into ELR-CGs possessed high viability and proliferation rate. The mechanical properties, porosity and swelling of the resulting ELR-CGs can easily be tuned by adjusting the ELR concentration. We also show that it is possible to replicate different patterns on the hydrogel surface, thus allowing the use of this type of hydrogel to improve applications that require cell guidance or even differentiation depending on the surface topography.

No abstract