**1. Introduction**

Antibacterial surfaces are very important with regard to minimizing infectious diseases which are one of the main causes of mortality worldwide [1]. This problem is mainly due to the increasing resistance of pathogenic microorganisms to antibiotics applied in clinical practice [2] Heterocyclic compounds have major role in the design and investigations of new bioactive drugs [3,4] Therefore acridine derivatives are one of the intensively exploited organic fluorophores in which fluorescence color intensity depends strongly on the polarization of their chromophoric system [5,6]. Possessing a heteroaromatic polycyclic molecule acridine derivatives are well known for their DNA intercalating abilities and pharmacological activity. That has led to the design and preparation of acridine compounds with anticancer, antimalarial, antiviral and antifungal activities [5–10].

Dendrimers are macromolecules with well-defined molecular weight and a high degree of branching units containing different reactive functional groups to which substances with biological activity may be attached by a chemical bond or by weak intermolecular interactions [11]. Compared to the low molecular weight bioactive compounds, dendrimers have the potential to deliver a large dose of biologically active substances, depending on the dendrimer generation. [12,13]. On the other hand, dendrimers containing metal ions, or metal nanoparticles also exhibit good biological activity [14–17].

Cotton fabrics are natural polymers, that have properties, such as high water absorptivity and air permeability and which are used for the production of textile products with different applications [18,19]. One of the major drawbacks of ordinary cotton fabrics is the possibility of being colonized by pathogenic microorganisms forming biofilms leading to undesired hygienic problems [20,21]. In the medical and clinical practice, cotton materials are used to obtain antibacterial textiles like wound dressings, hospital linen, sterile surgical materials, etc. [22]. Therefore, the improvement of their antimicrobial resistance is of major importance.

In this paper, the peripheral modification of a second-generation poly (propylene imine) dendrimer with acridine fluorophores has been described for the first time. Its copper complex has also been obtained and characterized. The spectral characteristics of the new fluorescent dendrimer have been investigated in different organic solvents. The antimicrobial activity of the dendrimers in agar, liquid medium and after their deposition on a textile material has also been tested. The cytotoxicity of the dendrimers has been evaluated in vitro in the model HEp-2 cell line.
