Besides the “green” technologies, researchers have also studied the usage of “green” modifying
antimicrobial agents, such as natural biopolymers extracted from animals or plants, namely chitosan,
cyclodextrin, sericin, alginate and others, which are renewable and have the potential to be a key
resource in the development of sustainable bioactive textiles [120]. Hu et al., for instance, used a “green”
approach to modify cellulose fibers’ surface by using alkali lignin as a functional agent to bind onto the
fibers’ surface, then complexed with silver cations and reduced them to atomic silver by growing into
nanoparticles [121]. Khurshid et al. have developed an eco-friendly natural antimicrobial textile finish
for cotton, using extracted Aloe vera gel mixed with an active substance of Neem plants. This hybrid
combination presented an effective antibacterial and antifungal activity and even good durability to
washing [122].