Liposome-Encapsulated Photosensitizers Against Bacteria

Abstract

Photodynamic therapy (PDT), utilizing photosensitizers and light, has received considerable interests for its potential to treat microbial infections. The advantages of antimicrobial PDT include a broad spectrum of action, efficient killing against wild-type as well as drug-resistant pathogens. Therefore, antimicrobial PDT could be valuable to rapidly reduce the microbial burden during the management of local infections, especially for the antibiotic resistance. A variety of photosensitizers have been examined its efficacy against pathogens. To increase the efficacy of photosensitizers, various drug delivery systems have been developed. Among these carrier systems, liposomes showed their PDT efficacy and safety in delivering photosensitizers. This review is focused on the application of liposomes mediated photodynamic inactivation of bacteria along with the discussion of few of recent patents.

Non-conventional therapeutics for oral infections

“…However, other effective approaches include using agents with strong cationic charge to enhance binding to Gram-negative bacteria 44 and liposome encapsulation to enhance delivery by fusion with the membrane. 45,46 In each case though, the degree of killing will still depend upon the efficiency of the photosensitizer being used.…”

Antibacterial photodynamic therapy: overview of a promising approach to fight antibiotic-resistant bacterial infections

“…Consequently, liposomes can encapsulate both hydrophilic and lipophilic PSs [32] for delivery into bacteria [191]. In fact, liposomes have been recommended for these purposes due to their fluidic lipophilic nature and the possibility to bear a positive surface charge [191].…”

“…Consequently, liposomes can encapsulate both hydrophilic and lipophilic PSs [32] for delivery into bacteria [191]. In fact, liposomes have been recommended for these purposes due to their fluidic lipophilic nature and the possibility to bear a positive surface charge [191]. Cationic carriers can disorganize the native threedimensional architecture of the bacterial cell envelope, thereby inducing membrane permeability and easier transmembrane passage or settlement of the PS [192].…”

“…Cationic carriers can disorganize the native threedimensional architecture of the bacterial cell envelope, thereby inducing membrane permeability and easier transmembrane passage or settlement of the PS [192]. The increased cytotoxicity of liposome-delivered PS relative to control delivery (unencapsulated PS) may also be ascribed to the more suitable localization of the PS in the cell envelope [191,192]. Proofof-principle for liposomal PS delivery has been provided in methicillin-resistant S. aureus and P. gin-gialis, where highly cytotoxic APDT was achieved with cationic liposome-delivered ZnPc [193].…”

Applications of phototheranostic nanoagents in photodynamic therapy

“…a semiconductor particle that is so small that it exhibits quantum mechanical properties), metal nanoparticles [161][162][163][164][165][166][167][168], liposomes, dendrimers [169][170][171][172][173], carbon nanotubes [174,175], and particles of silica and iron oxide [176][177][178][179]. In vivo efficacy of a phototheranostic is determined by factors such as the particle size and functionalization of the surface.…”