**4. Conclusions**

Grafting of PHEMA and poly(HEMA-*co*-PEGMA) hydrogels onto the surface of PET fabrics was achieved by two methods: Photochemical crosslinking and gamma irradiation. Photochemical crosslinking used less energy to achieve a smooth and thin (~50 microns) coverage of the PET fabric not affecting the fiber diameter. The hydrogel cover changed the thermal behavior of the PET fabric, increasing its *Tg* with increased crosslinking of the hydrogel and decreasing the *Tg* with the increase in the PEGMA content. The grafted hydrogel was able to contain silver nanoparticles distributed randomly and able to inhibit bacterial growth against *S. aureus* and *E. coli*. Gamma irradiation was used to graft more profoundly PHEMA and poly(HEMA-*co*-PEGMA) into PET fabric, resulting in a thicker coverage of the surface of the fabric (600 microns), and therefore increasing the diameter of the single fibers, with similar impact on thermal properties of PET than the photochemical method; the gamma irradiation modified PET was also able to contain randomly distributed silver nanoparticles. The hydrogel coating containing silver nanoparticles was able to inhibit the growth of *S. aureus* to a

similar extent than the photochemical method and inhibit better the growth of *E. coli* than the other method. Hydrogel-coated fabrics by both methods were highly hydrophilic.

**Author Contributions:** Conceptualization, Á.L.-C. and E.B.; methodology, K.A.M.-V., E.B., S.P.-S., and J.B.-S.; validation, K.A.M.-V., A.R.-J., and A.F.L.-N.; formal analysis, Á.L.-C.; investigation, K.A.M.-V. and J.B.-S.; resources, Á.L.-C., E.B., and A.F.L.-N.; writing—original draft preparation, K.A.M.-V. and A.R.-J.; writing—review and editing, S.P.-S., Á.L.-C., and A.F.L.-N.; supervision, Á.L.-C., E.B., and A.F.L.-N.; project administration, Á.L.-C., E.B., and A.F.L.-N.; funding acquisition, Á.L.-C., E.B., and A.F.L.-N.

**Funding:** This investigation was supported by grants from the National Council of Science and Technology of México [CONACYT-CNPq 2011-174378] and [CONACYT-CB-2012-178709], by a gran<sup>t</sup> from the Tecnológico Nacional de México [TNM-5635.15-P] and from CICESE [685-101].

**Acknowledgments:** Technical support by Pedro Navarro-Vega and Felipe <sup>L</sup>ópez-Saucedo is gratefully acknowledged.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
