Search

In this work, we described the combination of photocurable methacrylic monomer and poly(glycerol adipate) (PGA) macromer to form networks that can be further quaternized to provide antimicrobial character. Both monomers were synthesized enzymatically. Networks with different content of methacrylic monomer were prepared and further characterized by water contact angle measurements, surface charge, soluble fractions, differential scanning calorimetry and microhardness to determine the effect of the methacrylic monomer in the PGA network. Methacrylic monomer affected the mechanical behavior but did not alter the surface wettability, whereas the quaternization did not alter the wettability nor the mechanical properties of the network surfaces. Finally, the obtained network with the introduced permanent cationic charges were tested against Gram-positive S. aureus and Gram-negative E. coli bacteria showing remarkable antimicrobial activity which increased with the content of methacrylic monomer in the network. Moreover, the assays against red blood cells demonstrated that networks are no toxic.

The catalytic specificity of Lipase B from Candida antarctica (CALB) has been exploited to achieve specific terminal groups for the synthesis of glycerol poly(ester)s. This permits the preparation of glycerol-derived macromers able to undergo further reactions/chemical modifications for customization as functional systems and building blocks for polymer synthesis. Poly(glycerol adipate) based macromers with different terminal structures were achieved from the reaction between glycerol and divinyl adipate by varying the stoichiometry (from equimolar to 1.5 and 3.0 excess either of glycerol or divinyl adipate) and amount of catalyst (1 and 3 wt%). In the course of polymerization, transesterification and hydrolysis reactions occur over vinyl functionalities that result in acid endgroups. Thus, the resulting macromers are either terminated with hydroxyl groups and/or acid groups and/or vinyl groups. Therefore, an understanding of how acid functionality appears (from vinyl groups hydrolysis) and its quantification under various conditions may provide an opportunity for the design of synthetic strategies to avoid acid production and obtain the desired structures. Endgroup analysis was carried out using H NMR and C NMR spectroscopies and MALDI-TOF spectrometry. Mainly linear hydroxyl and vinyl-terminated macromers were obtained with high efficiency without significant hydrolysis of the chain ends (for vinyl terminated).