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Browsing by Author "Palasuk, Jadesada"
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Item Attachment and proliferation of dental pulp stem cells on dentine treated with different regenerative endodontic protocols(Wiley, 2017) Alghilan, M. A.; Windsor, L. Jack; Palasuk, Jadesada; Yassen, Ghaeth H.; Department of Endodontics, School of DentistryAim To investigate the attachment and proliferation of dental pulp stem cells (DPSC) on dentine treated with various endodontic regeneration protocols. Methodology Standardized dentine samples were irrigated with sodium hypochlorite (1.5% NaOCl) and ethylenediaminetetraacetic acid (17% EDTA) and randomized into four treatment groups and two control groups. The treatment groups were treated with a clinically used concentration of triple antibiotic paste (TAP), double antibiotic paste (DAP), calcium hydroxide (Ca(OH)2) or diluted TAP in a methylcellulose system (DTAP) for 1 week. Each sample in the treatment groups was then irrigated with EDTA. The two control groups were treated with EDTA or received no treatment. Dental pulp stem cells were seeded on each dentine specimen (10 000 cells). Lactate dehydrogenase activity assays were then performed to evaluate the attached DPSC after 1 day of incubation. Water-soluble tetrazolium assays were used to determine DPSC proliferation after three additional days of incubation. Friedman's test followed by least significant difference were used for statistical analyses (α = 0.05). Results Triple antibiotic paste and DTAP regeneration protocols, as well as EDTA-treated dentine, caused significant increases in DPSC attachment to dentine. Triple antibiotic paste, DAP and Ca(OH)2 regeneration protocols caused significant reductions in DPSC proliferation on dentine. However, the DTAP regeneration protocol did not have any significant negative effects on DPSC proliferation. Conclusions The clinically used endodontic regeneration protocols that include the use of TAP, DAP or Ca(OH)2 medicament negatively affected DPSC proliferation on dentine. However, the use of DTAP medicament during regenerative endodontic treatment may not adversely affect the proliferation of DPSC.Item A Bi-Mix Antibacterial Drug-Delivery System for Regenerative Endodontics(Office of the Vice Chancellor for Research, 2013-04-05) Palasuk, Jadesada; Hippenmeyer, Lauren; Gregory, Richard L.; Platt, Jeffrey A.; Spolnik, Kenneth J.; Bottino, Marco C.Traumatic injuries to immature teeth have traditionally been managed via apexification therapy with intracanal calcium hydroxide/Ca(OH)2. Recently, the use of a bi-mix (metronidazole-MET and ciprofloxacin-CIP) paste appears to provide more predictable results. The objective of this study was to fabricate/characterize polydioxanone (PDSII®)-based electrospun bi-mix drug-delivery systems incorporated with the combination of MET and CIP. The antibacterial property of the released media was tested against Enterococcus faecalis (Ef), Porphyromonas gingivalis (Pg) , Aggregatibacter actinomycetemcomitans (Aa). PDSII® was dissolved in HFP to obtain a 10wt.% solution. Either MET, CIP or distinct drug combinations were added into the solution followed by homogenization overnight. Six groups of study were employed: Control-100%PDS, G1-100%MET, G2-75%MET+25%CIP, G3- 50%MET+50%CIP, G4-25%MET+75%CIP and G5-100%CIP. Electrospinning was done based on optimized parameters to fabricate the distinct samples. Uniaxial microtensile testing (n=10), Fourier transform infrared spectroscopy/FTIR, scanning electron microscopy (SEM), and agar diffusion assay were used to characterize mechanical, chemical and antibacterial properties. One-way ANOVA (only for fiber diameter), Kruskal-Wallis and Mann-Whitney tests were performed (α=0.05). The results showed that uniaxial tensile strength was not significantly decreased compared to the control except G3. Average fiber diameters were in the nano-scaled range and significantly lower then the control. SEM imaging indicated a submicron fibrous morphology. FTIR confirmed the characteristic peaks for PDS as well as for the employed drugs. Agar diffusion assay suggested that the higher the CIP concentration the greater the antibacterial property against Ef, Pg and Aa. The results indicated that higher amount of CIP (G4 & G5) did not compromise mechanical properties of nanofibers and showed the highest bacterial inhibition against Ef, Pg and Aa. Optimization of the physical-mechanical properties, kinetics of drug release, and the effect of released drugs on dental pulp stem cells are currently being pursued. Partially funded by American Association of Endodontists/AAE (M.C.B.).Item Bimix antimicrobial scaffolds for regenerative endodontics(Elsevier, 2014-11) Palasuk, Jadesada; Kamocki, Krzysztof; Hippenmeyer, Lauren; Platt, Jeffrey A.; Spolnik, Kenneth J.; Gregory, Richard L.; Bottino, Marco C.; Department of Restorative Dentistry, IU School of DentistryINTRODUCTION: Eliminating and/or inhibiting bacterial growth within the root canal system has been shown to play a key role in the regenerative outcome. The aim of this study was to synthesize and determine in vitro both the antimicrobial effectiveness and cytocompatibility of bimix antibiotic-containing polydioxanone-based polymer scaffolds. METHODS: Antibiotic-containing (metronidazole [MET] and ciprofloxacin [CIP]) polymer solutions (distinct antibiotic weight ratios) were spun into fibers as a potential mimic to the double antibiotic paste (DAP, a MET/CIP mixture). Fiber morphology, chemical characteristics, and tensile strength were evaluated by scanning electron microscopy, Fourier transform infrared spectroscopy, and tensile testing, respectively. Antimicrobial efficacy was tested over time (aliquot collection) against Enterococcus faecalis (Ef), Porphyromonas gingivalis (Pg), and Fusobacterium nucleatum (Fn). Similarly, cytotoxicity was evaluated in human dental pulp stem cells. Data were statistically analyzed (P < .05). RESULTS: Scanning electron microscopy and Fourier transform infrared spectroscopy confirmed that electrospinning was able to produce antibiotic-containing fibers with a diameter mostly in the nanoscale. The tensile strength of 1:1MET/CIP scaffolds was significantly (P < .05) higher than pure polydioxanone (control). Meanwhile, all other groups presented similar strength as the control. Aliquots obtained from antibiotic-containing scaffolds inhibited the growth of Ef, Pg, and Fn, except pure MET, which did not show an inhibitory action toward Pg or Fn. Antibiotic-containing aliquots promoted slight human dental pulp stem cell viability reduction, but none of them were considered to be cytotoxic. CONCLUSIONS: Our data suggest that the incorporation of multiple antibiotics within a nanofibrous scaffold holds great potential toward the development of a drug delivery system for regenerative endodontics.Item Doxycycline-loaded nanotube-modified adhesives inhibit MMP in a dose-dependent fashion(Springer Nature, 2018-04) Palasuk, Jadesada; Windsor, L. Jack; Platt, Jeffrey A.; Lvov, Yuri; Geraldeli, Saulo; Bottino, Marco C.; Biomedical Sciences and Comprehensive Care, School of DentistryOBJECTIVES: This article evaluated the drug loading, release kinetics, and matrix metalloproteinase (MMP) inhibition of doxycycline (DOX) released from DOX-loaded nanotube-modified adhesives. DOX was chosen as the model drug, since it is the only MMP inhibitor approved by the U.S. Food and Drug Administration. MATERIALS AND METHODS: Drug loading into the nanotubes was accomplished using DOX solution at distinct concentrations. Increased concentrations of DOX significantly improved the amount of loaded DOX. The modified adhesives were fabricated by incorporating DOX-loaded nanotubes into the adhesive resin of a commercial product. The degree of conversion (DC), Knoop microhardness, DOX release kinetics, antimicrobial, cytocompatibility, and anti-MMP activity of the modified adhesives were investigated. RESULTS: Incorporation of DOX-loaded nanotubes did not compromise DC, Knoop microhardness, or cell compatibility. Higher concentrations of DOX led to an increase in DOX release in a concentration-dependent manner from the modified adhesives. DOX released from the modified adhesives did not inhibit the growth of caries-related bacteria, but more importantly, it did inhibit MMP-1 activity. CONCLUSIONS: The loading of DOX into the nanotube-modified adhesives did not compromise the physicochemical properties of the adhesives and the released levels of DOX were able to inhibit MMP activity without cytotoxicity. CLINICAL SIGNIFICANCE: Doxycycline released from the nanotube-modified adhesives inhibited MMP activity in a concentration-dependent fashion. Therefore, the proposed nanotube-modified adhesive may hold clinical potential as a strategy to preserve resin/dentin bond stability.Item Effect of surface treatments on microtensile bond strength of repaired aged silorane resin composite(2010) Palasuk, Jadesada; Platt, Jeffrey A., 1958-; Levon, John A.; Brown, David T.; Hovijitra, Suteera, 1944-; Cho, Sopanis D.Background: A silorane based resin composite, Filtek LS restorative, has been introduced to overcome the polymerization shrinkage of the methacrylate based resin composite. The repair of resin composite may hold clinical advantages. Currently, there is no available information regarding the repair potential of silorane resin composite with either silorane or methacrylate based resin composite. Objectives: The purpose of this study was to compare the repaired microtensile bond strength of aged silorane resin composite using different surface treatments and either silorane or methacrylate based resin composite. Methods: One hundred and eight silorane resin composite blocks (Filtek LS) were fabricated and aged by thermocycling between 8oC and 48oC (5000 cycles). A control (solid resin composite) and four surface treatment groups (no treatment, acid treatment, aluminum oxide sandblasting and diamond bur abrasion) were tested. Each treatment group was randomly divided in half and repaired with either silorane resin composite (LS adhesive) or methacrylate based resin composite (Filtek Z250/Single Bond Plus). Specimens were 12 blocks and 108 beams per group. After 24 hours in 37oC distilled water, microtensile bond strength testing was performed using a non-trimming technique. Fracture surfaces were examined using an optical microscopy (20X) to determine failure mode. Data was analyzed using Weibull-distribution survival analysis. Results: Aluminum oxide sandblasting followed by silorane or methacrylate based resin composite and acid treatment with methacrylate based resin composite provided insignificant differences from the control (p>0.05). All other groups were significantly lower than the control. Failure was primarily adhesive in all groups. Conclusion: Aluminum oxide sandblasting produced comparable microtensile bond strength compared to the cohesive strength of silorane resin composite. After aluminum oxide sandblasting, aged silorane resin composite can be repaired with either silorane resin composite with LS system adhesive or methacrylate based resin composite with methacrylate based dentin adhesive.Item Green tea catechin inhibits the activity and neutrophil release of Matrix Metalloproteinase-9.(Elsevier, 2016-10) Kim-Park, Wan K.; Allam, Eman S.; Palasuk, Jadesada; Kowolik, Michael; Park, Kichuel K.; Windsor, L. Jack; Department of Biomedical and Applied Sciences, IU School of DentistryGreen tea (Camellia sinensis; 綠茶 lǜ chá) extracts have been shown to possess anti-oxidant and anti-inflammatory effects in various cell types. Green tea extract (GTX) has been shown to significantly inhibit the activity of collagenase-3 (matrix metalloproteinase-13 (MMP-13)) in vitro. MMPs, such asItem Physicochemical and Biological Properties of Novel Chlorhexidine-Loaded Nanotube-Modified Dentin Adhesive(Wiley, 2018-09-10) Feitosa, Sabrina A.; Palasuk, Jadesada; Geraldeli, Saulo; Windsor, L. Jack; Bottino, Marco C.; Biomedical Sciences and Comprehensive Care, School of DentistryA commercially available three-step (etch-and-rinse) adhesive was modified by adding chlorhexidine (CHX)-loaded nanotubes (Halloysite®, HNT) at two concentrations (CHX10% and CHX20%). The experimental groups were: SBMP (unmodified adhesive, control), HNT (SBMP modified with HNT), CHX10 (SBMP modified with HNT loaded with CHX10%), and CHX20 (SBMP modified with HNT loaded with CHX20%). Changes in the degree of conversion (DC%), Knoop hardness (KHN), water sorption (WS), solubility (SL), antimicrobial activity, cytotoxicity, and anti-matrix metalloproteinase [MMP-1] activity (collagenase-I) were evaluated. In regards to DC%, two-way ANOVA followed by Tukey’s post-hoc test revealed that only the factor “adhesive” was statistically significant (p<0.05). No significant differences were detected in DC% when 20 s light-curing was used (p>0.05). For Knoop microhardness, one-way ANOVA followed by the Tukey’s test showed statistically significant differences when comparing HNT (20.82±1.65) and CHX20% (21.71±2.83) with the SBMP and CHX10% groups. All adhesives presented similar WS and cytocompatibility. The CHX-loaded nanotube-modified adhesive released enough CHX to inhibit the growth of S. mutans and L. casei. Adhesive eluates were not able to effectively inhibit MMP-1 activity. The evaluation of higher CHX concentrations might be necessary to provide an effective and predictable MMP inhibition.Item Synthesis, characterization and matrix metalloproteinase inhibition of doxycycline modified dental adhesives(2015) Palasuk, Jadesada; Windsor, L. Jack; Bottino, Marco C.; Platt, Jeffrey A.; Lee, Chao-Hung; Geraldeli, SauloThe biodegradation of the hybrid layer of dental restorations is due in part to the degradation of the demineralized collagen by matrix metalloproteinases (MMPs). During the bonding procedure, phosphoric acid/acidic primers activate MMPs that degrade denuded type I collagen. As a result, the hybrid layer loses its integrity overtime, leading to the failure of the resin composite restoration. This study aimed to evaluate doxycycline (DOX) for its effects on preventing the degradation of the hybrid layer through the modification of the dental adhesive with aluminosilicate clay nanotubes (HNT) loaded with doxycycline. Doxycycline was encapsulated into HNT at three distinct concentrations (10%, 20% and 30% DOX, w/v). The increases in the concentration of doxycycline significantly increased the amount of doxycycline that was encapsulated into HNT and the drug loading into the HNT. Conversely, the encapsulation efficiency was significantly decreased with the increases in concentration of doxycycline. The modified adhesives were fabricated by incorporation of DOX-encapsulated HNT into a commercially available dental adhesive (Adper Scotchbond Multi-Purpose, SBMP). The degree of conversion (DC), Knoop microhardness, doxycycline release profiles, the biological activity (antibacterial and anti-MMP activity), and cytocompatibility of the modified adhesives were investigated. There were no statistically significant differences (p > 0.05) in DC and Knoop microhardness compared to the control (SBMP). None of the adhesive eluates was cytotoxic to the human dental pulp stem cells. Although higher concentrations of doxycycline led to a higher release of doxycycline from the modified adhesives, the differences were not significant (p = 0.259) among the groups (10%, 20% and 30% DOX). A significant growth inhibition of S. mutans and L. casei by direct contact illustrated successful encapsulation of doxycycline into the modified adhesives. Doxycycline released from the modified adhesives did not inhibit the growth of both cariogenic bacteria but inhibited MMP-1 activity. The results suggested that subantimicrobial levels of doxycycline were gradually released. The immediate microtensile bond strengths were not significantly different from those of the control (SBMP), suggesting no negative effect of doxycycline on dentin bonding (only 10% DOX were investigated). The long-term resin-dentin bond durability should be evaluated.