Tese_Tânia Vieira.pdf - Ubi Thesis

Chapter I - Introduction
Besides its antimicrobial activity, it has been recently found that AgNPs reduce cytokine
release (Guidelli et al. 2011), decreasing lymphocyte and mast cell infiltration and also induce
apoptosis of inflammatory cells (Chaloupka et al. 2010). These characteristics of AgNPs are
responsible for the anti-inflammatory effect and contributes for accelerating the
epithelialization by over 40% and, as a consequence, accelerate wound healing (Lu et al. 2008;
Chaloupka et al. 2010; Kalishwaralal et al. 2010).
1.3.1. Applications of silver nanoparticles
The properties presented by AgNPs make them good candidates to be used in different
applications, like in electronics and in sensor design based on the surface-enhanced Raman
spectroscopy (SERS) (Badawy et al. 2010; Parashar et al. 2011). Moreover, these nanoparticles
have been used in a number of medical applications (Arora et al. 2009), due to the antimicrobial
activity owned by the silver-based compounds containing ionic silver or metallic silver (Panác ek
et al. 2006; Arora et al. 2008).
Some applications of silver and AgNPs are presented in figure 1. In the case of silver, it is
used in the form of AgNO 3 solutions to perform cauterization, in order to stop epistaxis and the
growth of post-traumatic granulomas (Chaloupka et al. 2010). AgNO 3 is also used to prevent
some infections and to promote an anti-inflammatory effect in the procedure of pleurodesis
(Chaloupka et al. 2010). Silver is also used in the form of silver sulfadiazine cream to apply in
ulcers and burns to promote the skin regeneration (Chaloupka et al. 2010).
AgNPs have been used as coating material for medical purposes, orthopedic, vascular or
dental graft materials (Panác ek et al. 2006; Ruparelia et al. 2008; Vertelov et al. 2008),
indwelling catheters (Vasilev et al. 2010), and arthroplasty (Panác ek et al. 2006). AgNPs can be
impregnated in wound dressings (Xu et al. 2011), in diabetic ulcers (Ip et al. 2006; Li et al.
2011), in chronic ulcers, and in traumatic injuries in order to prevent infections and enhance
wound repair (Ip et al. 2006). Some medical products containing AgNPs available in the market,
as wound dressings and catheters, are presented in table 1 (Arora et al. 2009; Chaloupka et al.
2010).
Moreover, silver can also be employed to eliminate microorganisms on textile products,
food storage containers, cosmetics in the form of nanogels and nanolotions, contraceptive
devices, and they can be used for water filtration too (Monteiro et al. 2009; Shameli et al. 2010;
Vasilev et al. 2010; Mirzajani et al. 2011).
9