Photodynamic therapy disinfection of carious tissue mediated by aluminum-chloride-phthalocyanine entrapped in cationic liposomes: an in vitro and clinical study

Abstract

Photodynamic therapy (PDT) is a technique employed in the treatment of several superficial infections, such as caries. PDT uses a non-toxic drug termed photosensitizer (PS) followed by light irradiation. The cytotoxic effects of the therapy are related to the production of reactive species produced after light activation of a photosensitizer, which reacts with surrounding molecules and disrupts several of the cell's functions. Within this context, this study aimed to develop a clinical protocol involving PDT application mediated by aluminum-chloride-phthalocyanine (AlClPc) entrapped in cationic liposomes against cariogenic bacteria in caries lesions. Cationic liposomes were used to delivery AlClPc preferentially to bacterial cells due to the strong anionic superficial charges of these cell types. The results are represented in two fundamental steps: (1) in vitro evaluation of AlClPc delivery to cariogenic bacteria and pulp cells, as well as its potential phototoxicity; (2) a clinical study involving volunteer patients that were treated with the PDT protocol mediated by AlClPc-cationic liposome. The main results showed that the AlClPc-cationic liposome was preferentially absorbed by bacterial cells compared to eukaryotic dental pulp cells, and it was efficient in the reduction of microbial load from bacterial cultures. In addition, the clinical study showed a mean reduction of 82% of total bacterial in the treated cavities after PDT application. Taken together, the results presented in this study showed that the antimicrobial PDT protocol mediated by cationic liposomes containing AlClPc is safety for clinical application and is efficient in the reduction of bacterial load in caries lesions.

Effect of the antimicrobial photodynamic therapy on microorganism reduction in deep caries lesions: a systematic review and meta-analysis

“…In the included articles, the sample size ranged from 10 to 90 teeth. Of the six selected articles, only Longo et al 11 did not provide the patient age. One article 12 did not …”

“…7,8 aPDT has recently been studied as a coadjuvant therapy against microorganisms of dental caries, which suggests that it might be useful as adjunctive therapy to current deep carious lesion. [9][10][11][12][13][14] Therefore, the aim of this study was to perform a systematic review and meta-analysis to evaluate the effect of aPDT as a coadjuvant therapy in reducing microorganisms in deep carious lesions.…”

Liposomal systems as carriers for bioactive compounds

“…Such systems can be used as biomimetic models for studies of interaction with various hydrophobic drugs and membrane proteins, with potential applications in the field of immunology (vaccines and drugs targeting specific cell membranes). Liposomes associated with proteins can be used to study the activity of photosensitive dyes applied during photodynamic therapy (Bolfarini et al 2012;Longo et al 2012;Rocha et al 2012;Bicalho et al 2013;Faria et al 2015), as well for studies related to the ability of proteins to prevent, treat and/or act as nanosensors for various diseases (Daghastanli et al 2004;Santos et al 2006;Zucolotto et al 2007;Migliaccio et al 2008;Colhone et al 2009Colhone et al , 2015Calderon et al 2009a, b;Perinoto et al 2010;Paulovich et al 2011;Barbosa et al 2011;Salay et al 2011;Barros et al 2013;Fotoran et al 2015).…”

Photodynamic inactivation of biofilms formed by Candida spp., Trichosporon mucoides, and Kodamaea ohmeri by cationic nanoemulsion of zinc 2,9,16,23-tetrakis(phenylthio)-29H, 31H-phthalocyanine (ZnPc)

“…Longo et al [27] developed a clinical protocol involving PDI application mediated by aluminum-chloridephthalocyanine entrapped in cationic liposomes against cariogenic bacterials. In addition, the authors evaluated the cytotoxicity of the proposed PDI protocol in eukaryotic cells.…”

“…The main advantage in the use of phthalocyanine as photosensitizer is the fact that this family of dyes could act by the two classical PDI mechanisms of radical production (type I) or singlet oxygen (type II) [31]. These photosensitizers are more effective in ROS generation after light activation and have less capacity to stain dental structures compared to the traditional phenothiazine molecules [27].…”