Influence of silver nanoparticles on the tissue reaction of polyacrylic acid-based gel.

Purpose: To study the influence of silver nanoparticles (AgNP) on tissue reaction when incorporated into a polymeric matrix of polyacrylic acid-based (Carbopol®) gel as a proposal for a new low-cost type of biomaterial that is simple to manufacture for use as an antimicrobial and antioxidative dressing.

Methods: In-vivo tests of implantation in the subcutaneous tissue of the back of rats were performed using polyethylene tubes in three situations: empty, only the gel, and gel incorporated with AgNP. Then, the tissue reaction was studied by counting inflammatory cells. Additionally, in-vitro tests of the antioxidative and antimicrobial activity of AgNP were performed. The radical 2,2 diphenyl-1 picrylhydrazyl (DPPH) was used to test the antioxidative activity of AgNP using electron spin resonance. The antimicrobial activity of AgNP was determined by minimum inhibitory concentration against the microorganisms: Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli.

Results: The results indicated that AgNP presents antioxidative activity and was able to inhibit the growth of the microorganisms tested. The addition of AgNP in Carbopol® did not alter the tissue inflammatory response (p>0.05, Kruskal-Wallis's test).

Conclusions: The new biomaterial is promising for future use as a dressing for its beneficial properties for regenerative processes.