Antimicrobial photodynamic therapy assessment of three indocyanine green-loaded metal-organic frameworks against Enterococcus faecalis

• Published in: Photodiagnosis and photodynamic therapy 2018-09, Vol.23, p.331-338
• Main Authors: Golmohamadpour, Azadeh, Bahramian, Bahram, Khoobi, Mehdi, Pourhajibagher, Maryam, Barikani, Hamid Reza, Bahador, Abbas
• Format: Article
• Language: English
• Subjects: Antimicrobial photodynamic therapy; Bicuspid; Biofilm formation; Biofilms - drug effects; Drug Stability; Enterococcus faecalis; Enterococcus faecalis - drug effects; Humans; Indocyanine green; Indocyanine Green - administration & dosage; Indocyanine Green - pharmacology; Lasers, Semiconductor; Metal organic framework; Metal-Organic Frameworks - chemistry; Nanoparticles - chemistry; Photochemotherapy - methods; Photosensitizing Agents - administration & dosage; Photosensitizing Agents - pharmacology; Real-Time Polymerase Chain Reaction
• ISSN: 1572-1000; 1873-1597
• DOI: 10.1016/j.pdpdt.2018.08.004

[Display omitted] •Three different MOFs were prepared and compared for ICG loading and stability.•MIL-101-based MOFs showed the best ICG loading and aqueous stability after 10 days.•ICG-free MOFs surprisingly suppressed the viability of E. faecalis after laser irradiation.•Fe-101-ICG mediated aPDT could reduce the count of E. faecalis to 62.67% and the expression of esp gene to 6.2-fold. Antimicrobial photodynamic therapy (aPDT) has emerged as one of the promising non-invasive adjuvant treatments of endodontic infections. The key part of this technique is application of an optimized nontoxic photosensitizer (PS), like indocyanine green (ICG) which when activated by light can destroy bacterial contaminants. Notwithstanding all featured properties of ICG, this PS mainly suffers from the lack of stability and concentration-dependent aggregation. A variety of nanomaterials (NMs) has been widely exploited to improve the stability and efficiency of ICG. The objective of this study was to evaluate and compare the efficiency of three high capacious metal organic frameworks (MOFs) to produce MOF-ICG as novel PSs improving ICG loading, stability and antimicrobial activity. This is first report on ICG-loaded MOFs for aPDT against endodontic infections. Three different nano-MOFs were synthesized (denoted as Fe-101, Al-101 and Fe-88), and employed for ICG loading (MOF-ICG). The stability of immobilized ICG, antimicrobial and anti-biofilm properties of MOF-ICG against Enterococcus faecalis (E. faecalis) as one of the main factors of endodontic infections as well as expression ratio of the esp gene in E. faecalis were evaluated. Fe-101 and Al-101 showed acceptable ICG loading (ICG loading capacity of 16.93 ± 0.32 and 18.17 ± 0.31, respectively) as well as considerable enhanced aqueous stability (percent of degradation were only 14% and 17%, respectively) in comparison to free ICG (percent of degradation was 95%) after 10 days. ICG-free MOFs could surprisingly suppress the viability of E. faecalis after laser irradiation up to 18.1%, 28.8%, and 38.3% for Al-101, Fe-88 and Fe-101, respectively. ICG loaded MOFs mediated aPDT could significantly reduce the count of E. faecalis to 60.72%, 45.12%, and 62.67%, respectively (p