Conjugate of chitosan nanoparticles with chloroaluminium phthalocyanine: Synthesis, characterization and photoinactivation of Streptococcus mutans biofilm

Author(s)

Unten Takahashi, Luandra Aparecida ^[1] ; Milori Corona, Silmara Aparecida ^[2]

Affiliation

^[1] FFCLRP Univ Sao Paulo USP, Ctr Nanotechnol & Tissue Engineers, Dept Chem, Photobiol & Photomed Res Grp, Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Ribeirao Preto Sch Dent, Dept Restorat Dent, Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: Photodiagnosis and Photodynamic Therapy; v. 30, JUN 2020.
• Web of Science Citations: 0

Abstract

Background: Antimicrobial photodynamic therapy (aPDT) using chloroaluminium phthalocyanine (ClAlPc) has high oxidative power allowing for the control of biofilms, especially when the photosensitizer is administered in an appropriate release vehicle. This study aimed to develop/characterize the ClAlPc encapsulated in chitosan nanoparticles (CSNPs), and evaluate its antimicrobial properties against S. mutans biofilms. Methods: CSNPs were prepared by ion gelation, and characterization studies included particle size, polydispersion index (IPd), zeta potential, accelerated stability, absorption spectrum and ClAlPc quantification. The S. mutans biofilms were formed in bovine dentin blocks at 37 degrees C for 48 h under microaerophilic conditions. 8 mu M ClAlPc was combined with a diode laser (InGaAlP) at 660 nm and 100 J/cm(2). The aPDT toxicity was verified by dark phototoxicity. The antimicrobial activity was verified by CFU/mL and biofilm was analyzed by scanning electron microscopy (SEM). The number of viable bacteria was analyzed by ANOVA and Tukey HSD tests (alpha = 0.05). Results: The characterization revealed that the ClAlPc nanoparticles were found in nanometer-scale with adequate photophysical and photochemical properties. The aPDT mediated by ClAlPc + CSNPs nanoconjugate showed a significant reduction in the viability of S. mutans (1 log10 CFU/mL) compared to the negative control (PBS, p < 0.05). The aPDT mediated by ClAlPc was similar to PBS (p > 0.05). SEM revealed change in biofilm morphology following the treatment of bacteria with aPDT ClAlPc + CSNPs. Cells were arranged as single or in shorted chains. Irregular shapes of S. mutans were found. Conclusion: ClAlPc nanoparticles are considered stable and aPDT mediated by ClAlPc + CSNPs nanoconjugate was effective against S. mutans biofilm. (AU)

• FAPESP's process: 13/50181-1 - Use of drugs containing nanocarriers with photosensitizers and/or other active compounds applied to cell therapy and treatment of central nervous system disorders
• Grantee: Antonio Claudio Tedesco
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 19/05965-0 - Evaluation of antimicrobial photodynamic therapy on heterogeneous cariogenic biofilm mediated by chloro-aluminum phthalocyanine encapsulated in chitosan nanoparticles
• Grantee: Silmara Aparecida Milori Corona
• Support Opportunities: Regular Research Grants