International journal of molecular sciencesarticle polymeric nanoparticle-based photodynamic therapy for chronic periodontitis in vivo

Research performed at:

1. Faculdade de Ciencias Farmaceuticas, UNESP—Univ Estadual Paulista, Brazil.

2. Instituto de Fisica de Sao Carlos, Universidade de Sao Paulo, Brazil.

3. Applied Molecular Photomedicine Laboratory, the Forsyth Institute, Cambridge, USA.

4. Department of PharmaceuticalSciences, School of Pharmacy, Bouvé College of Health Sciences,USA.

The authors:

Laura Marise de Freitas, Giovana Maria Fioramonti Calixto, Marlus Chorilli, Juçaíra Stella M. Giusti, Vanderlei Salvador Bagnato, Nikolaos S. Soukos, Mansoor M. Amiji, Carla Raquel Fontana.

High rates of artemisinin-based combination therapy (ACT) failures in the treatment of Plasmodium falciparum malaria in Southeast Asia have led to triple drug strategies to extend the useful life of ACTs.

Antimicrobial photodynamic therapy (aPDT) is increasingly being explored for treatment of periodontitis. Here, we investigated the effect of aPDT on human dental plaque bacteria in suspensions and biofilms in vitro using methylene blue (MB)-loaded poly(lactic-co-glycolic) (PLGA) nanoparticles (MB-NP) and red light at 660 nm. The effect of MB-NP-based aPDT was also evaluated in a clinical pilot study with 10 adult human subjects with chronic periodontitis.

Dental plaque samples from human subjects were exposed to aPDT—in planktonic and biofilm phases—with MB or MB-NP (25 μg/mL) at 20 J/cm2 in vitro. Patients were treated either with ultrasonic scaling and scaling and root planing (US + SRP) or ultrasonic scaling + SRP + aPDT with MB-NP (25 μg/mL and 20 J/cm2) in a split-mouth design. In biofilms, MB-NP eliminated approximately 25% more bacteria than free MB.

The clinical study demonstrated the safety of aPDT. Both groups showed similar improvements of clinical parameters one month following treatments. However, at three months ultrasonic SRP + aPDT showed a greater effect (28.82%) on gingival bleeding index (GBI) compared to ultrasonic SRP. The utilization of PLGA nanoparticles encapsulated with MB may be a promising adjunct in antimicrobial periodontal treatment.