In situ nanoparticle formation embedded into hydrogel matrix, acting as container and stabilizer for nanoparticle reaction was the focus in this research; this method was realized using AgNO 3 (0.75 and 1.0 M) as silver source for nanoparticle formation; also, monomers (HEMA), cross-linker agents (DEGDMA) and a photoinitiator (Irgacure 651) were used for the hydrogel synthesis. For the reduction of Ag ? ? Ag 0 , the reaction mixture was irradiated with an UV lamp at 365 nm for 30 min; parallel to this process, the hydrogel photopolymerization occurs. All these systems were studied by Infrared and Raman Spectroscopy, optical studies: UV/Vis absorption, thermal studies: differential scanning calorimetry and thermogravimetric analysis, X-ray diffraction, fluorescence X-ray spectroscopy and transmission electronic microscopy. Characterization techniques are capable to detect the presence of non-agglomerated silver nanoparticles homogeneously distributed in all the systems. X-Ray photoemission spectroscopy establishes the presence of Ag 0 and Ag ? as mixture in the synthesized composite. Quantitative assays show that the sample Ag_Hg3-89.5 % (1.0 M) presents an important biocide property, by reducing 99.9 % of bacterium Escherichia coli ATCC 25922 as compared with the alone hydrogel used as control.

Bioglass nanoparticles (n‐BGs, 54SiO2:40CaO:6P2O5 mol %) with about 27 nm diameter were synthesized by the sol–gel method and incorporated into a poly(lactic acid) (PLA) matrix by the melting process in order to obtain nanocomposites with filler contents of 5, 10, and 25 wt %. Our results showed that during the cooling scan, the crystallization temperature (Tc) of the PLA/n‐BG nanocomposites decreased 13°C as compared to neat PLA. The presence of nanoparticles also decreased the thermal stability of the PLA matrix, as nanocomposites presented up to about 20°C lower degradation temperatures in a nitrogen atmosphere. The presence of n‐BG increased the stiffness of the polymer matrix, and for instance the composite with 25 wt % of filler presented about 52.6% higher Young's modulus than neat PLA. n‐BG incorporation into PLA increased also the hydrolytic degradation of the polymer over time. When the PLA composites were immersed in simulated body fluid, an apatite layer was formed on their surface, as verified by Fourier transform infrared, X‐Ray Diffraction (XRD), and scanning electron microscopy‐EDS, showing that the presence of n‐BG induced bioactivity on the PLA matrix. Moreover, the viability of cervical uterine adenocarcinoma cells was higher on PLA/n‐BG nanocomposite with 25 wt % of filler. The presence of n‐BG barely gave an antibacterial effect on the polymer matrix, despite the well‐known biocidal properties of these nanoparticles. Our results show that the presence of n‐BGs is a proper route for improving the bioactivity of PLA with potential application in tissue engineering.

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