Azadeh Golmohamadpour1, Bahram Bahramian1, Mehdi Khoobi2, Maryam Pourhajibagher3, Hamid Reza Barikani4, Abbas Bahador5. 1. College of Chemistry, Shahrood University of Technology, Shahrood, P.O. Box 36155-316, Iran. 2. The Institute of Pharmaceutical Sciences (TIPS), Tehran University of Medical Sciences, Tehran, Iran; Department of Pharmaceutical Biomaterials and Medical Biomaterials Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: m-khoobi@tums.ac.ir. 3. Dental Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. 4. Dental Implant Research Center, Dentistry Research Institute, Tehran University of Medical Sciences, Tehran, Iran. 5. Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Electronic address: Ab.bahador@gmail.com.
Abstract
BACKGROUND: 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. MATERIALS AND METHODS: 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. RESULTS: 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 < 0.05). The Fe-88-ICG-PDT, Fe-101-ICG-PDT and Al-101-ICG-PDT considerably dropped the biofilm formation of E. faecalis by 37.54%, 47.01% and 53.68% (p < 0.05). The expression of esp gene was also remarkably declined to 4.4-, 6.0- and 6.2-fold after aPDT in the presence of Fe-88-ICG, Al-101-ICG and Fe-101-ICG, respectively (P < 0.05). CONCLUSION: Owing to the significant features of the Fe-101 including acceptable ICG loading and stability, as well as reasonable antimicrobial effect after ICG loading in comparison to free ICG, it could be considered as a promising nano-PSs in aPDT to remove E. faecalis.
BACKGROUND: 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. MATERIALS AND METHODS: 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. RESULTS: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 < 0.05). The Fe-88-ICG-PDT, Fe-101-ICG-PDT and Al-101-ICG-PDT considerably dropped the biofilm formation of E. faecalis by 37.54%, 47.01% and 53.68% (p < 0.05). The expression of esp gene was also remarkably declined to 4.4-, 6.0- and 6.2-fold after aPDT in the presence of Fe-88-ICG, Al-101-ICG and Fe-101-ICG, respectively (P < 0.05). CONCLUSION: Owing to the significant features of the Fe-101 including acceptable ICG loading and stability, as well as reasonable antimicrobial effect after ICG loading in comparison to free ICG, it could be considered as a promising nano-PSs in aPDT to remove E. faecalis.
Authors: Manlin Qi; Minghan Chi; Xiaolin Sun; Xianju Xie; Michael D Weir; Thomas W Oates; Yanmin Zhou; Lin Wang; Yuxing Bai; Hockin Hk Xu Journal: Int J Nanomedicine Date: 2019-08-28
Authors: Patrícia Diogo; M Amparo F Faustino; M Graça P M S Neves; Paulo J Palma; Isabel P Baptista; Teresa Gonçalves; João Miguel Santos Journal: J Funct Biomater Date: 2019-09-30