Drug Delivery Systems That Eradicate and/or Prevent Biofilm Formation - Antibiofilm Agents: From Diagnosis to Treatment and Prevention - page 406

Fig. 4 Divergent synthesis of dendrimer: from core to surface

Fig. 5 Convergent synthesis of dendrimer: fragment condensation

Dendrimers acquire several unique properties that make them an excellent
platform for antimicrobial drug delivery. The highly branched nature of dendrimers
provides enormous surface area to size ratio and allows great reactivity with
microorganisms in vivo. In addition, both hydrophobic and hydrophilic agents
can be loaded into dendrimers. Hydrophobic drugs can be trapped inside the cavity
in the hydrophobic core and hydrophilic drugs can be linked to the multivalent
surfaces of dendrimers through covalent conjugation or electrostatic interaction
(Florence 2005 ; Gillies and Frechet 2005 ). The polycationic nature of dendrimer
biocides facilitates the initial electrostatic adsorption to negatively charged bacte-
ria. Glycopeptide dendrimers (branched oligopeptides) have great potential to block
P. aeruginosa biofilm formation and induce biofilm dispersal in vitro (Emma
et al. 2008 ) due to their high affinity toward the P. aeruginosa lectins LecB and
LecA, which are responsible for formation of antibiotic-resistant biofilms. The
dendrimeric peptide (RW) 4D has been shown to be active against multidrug-
resistant (MDR) S. aureus and E. coli (D31) as well as Acinetobacter baumannii
and E. coli RP437 (Hou et al. 2009 ).

5 Chitosan-Based Drug Delivery Systems

Chitosan is a natural cationic polymer that consists of D -glucosamine and N-actyl-
glucosamine linked via -(1,4)-glycosidic bonds and is obtained by the alkaline

deacetylation of chitin. It is nontoxic, biocompatible, biodegradable, and has

ʲ