Browsing by Author "Bottino, Marco C."
Now showing 1 - 10 of 63
Results Per Page
Sort Options
Item A Highly Ordered, Nanostructured Fluorinated CaP-Coated Melt Electrowritten Scaffold for Periodontal Tissue Regeneration(Wiley, 2021) Daghrery, Arwa; Ferreira, Jessica A.; de Souza Araújo, Isaac J.; Clarkson, Brian H.; Eckert, George J.; Bhaduri, Sarit B.; Malda, Jos; Bottino, Marco C.; Biostatistics, School of Public HealthPeriodontitis is a chronic inflammatory, bacteria-triggered disorder affecting nearly half of American adults. Although some level of tissue regeneration is realized, its low success in complex cases demands superior strategies to amplify regenerative capacity. Herein, highly ordered scaffolds are engineered via Melt ElectroWriting (MEW), and the effects of strand spacing, as well as the presence of a nanostructured fluorinated calcium phosphate (F/CaP) coating on the adhesion/proliferation, and osteogenic differentiation of human-derived periodontal ligament stem cells, are investigated. Upon initial cell-scaffold interaction screening aimed at defining the most suitable design, MEW poly(𝝐-caprolactone) scaffolds with 500 µm strand spacing are chosen. Following an alkali treatment, scaffolds are immersed in a pre-established solution to allow for coating formation. The presence of a nanostructured F/CaP coating leads to a marked upregulation of osteogenic genes and attenuated bacterial growth. In vivo findings confirm that the F/CaP-coated scaffolds are biocompatible and lead to periodontal regeneration when implanted in a rat mandibular periodontal fenestration defect model. In aggregate, it is considered that this work can contribute to the development of personalized scaffolds capable of enabling tissue-specific differentiation of progenitor cells, and thus guide simultaneous and coordinated regeneration of soft and hard periodontal tissues, while providing antimicrobial protection.Item Advanced biomaterials for periodontal tissue regeneration(Wiley, 2022) Daghrery, Arwa; Bottino, Marco C.; Biomedical and Applied Sciences, School of DentistryThe periodontium is a suitable target for regenerative intervention, since it does not functionally restore itself after disease. Importantly, the limited regeneration capacity of the periodontium could be improved with the development of novel biomaterials and therapeutic strategies. Of note, the regenerative potential of the periodontium depends not only on its tissue‐specific architecture and function, but also on its ability to reconstruct distinct tissues and tissue interfaces, suggesting that the advancement of tissue engineering approaches can ultimately offer new perspectives to promote the organized reconstruction of soft and hard periodontal tissues. Here, we discuss material‐based, biologically active cues, and the application of innovative biofabrication technologies to regenerate the multiple tissues that comprise the periodontium.Item Advanced Scaffolds for Dental Pulp and Periodontal Regeneration(Elsevier, 2017-10) Bottino, Marco C.; Pankajakshan, Divya; Nör, Jacques E.; Biomedical Sciences and Comprehensive Care, School of DentistryNo current therapy promotes root canal disinfection and regeneration of the pulp-dentin complex in cases of pulp necrosis. Antibiotic pastes used to eradicate canal infection negatively affect stem cell survival. Three-dimensional easy-to-fit antibiotic-eluting nanofibers, combined with injectable scaffolds, enriched or not with stem cells and/or growth factors, may increase the likelihood of achieving predictable dental pulp regeneration. Periodontitis is an aggressive disease that impairs the integrity of tooth-supporting structures and may lead to tooth loss. The latest advances in membrane biomodification to endow needed functionalities and technologies to engineer patient-specific membranes/constructs to amplify periodontal regeneration are presented.Item Antibacterial TAP-mimic electrospun polymer scaffold: effects on P. gingivalis-infected dentin biofilm(Springer, 2016-03) Albuquerque, Maria Tereza P.; Evans, Joshua D.; Gregory, Richard L.; Valera, Marcia C.; Bottino, Marco C.; Department of Anatomy & Cell Biology, IU School of MedicineOBJECTIVES: This study sought to investigate, in vitro, the effects of a recently developed triple antibiotic paste (TAP)-mimic polymer nanofibrous scaffold against Porphyromonas gingivalis-infected dentin biofilm. MATERIALS AND METHODS: Dentin specimens (4 × 4 × 1 mm(3)) were prepared from human canines. The specimens were sterilized, inoculated with P. gingivalis (ATCC 33277), and incubated for 1 week to allow for biofilm formation. Infected dentin specimens were exposed for 3 days to the following treatments: antibiotic-free polydioxanone scaffold (PDS, control), PDS + 25 wt% TAP [25 mg of each antibiotic (metronidazole, ciprofloxacin, and minocycline) per mL of the PDS polymer solution], or a saturated TAP-based solution (50 mg of each antibiotic per mL of saline solution). In order to serve as the negative control, infected dentin specimens were left untreated (bacteria only). To determine the antimicrobial efficacy of the TAP-mimic scaffold, a colony-forming unit (CFU) per milliliter (n = 10/group) measurement was performed. Furthermore, additional specimens (n = 2/group) were prepared to qualitatively study biofilm inhibition via scanning electron microscopy (SEM). Statistics were performed, and significance was set at the 5% level. RESULTS: Both the TAP-mimic scaffold and the positive control (TAP solution) led to complete bacterial elimination, differing statistically (p < 0.05) from the negative control group (bacteria only). No statistical differences were observed for CFU per milliliter data between antibiotic-free scaffolds (2.7 log10 CFU/mL) and the negative control (5.9 log10 CFU/mL). CONCLUSIONS: The obtained data revealed significant antimicrobial properties of the novel PDS-based TAP-mimic scaffold against an established P. gingivalis-infected dentin biofilm. CLINICAL RELEVANCE: Collectively, the data suggest that the proposed nanofibrous scaffold might be used as an alternative to the advocated clinical gold standard (i.e., TAP) for intracanal disinfection prior to regenerative endodontics.Item Antimicrobial Effects of Novel Triple Antibiotic Paste-Mimic Scaffolds on Actinomyces naeslundii Biofilm(Elsevier, 2015-08) Albuquerque, Maria T.P.; Ryan, Stuart J.; Münchow, Eliseu A.; Kamocka, Maria M.; Gregory, Richard L.; Valera, Marcia C.; Bottino, Marco C.; Department of Medicine, IU School of MedicineINTRODUCTION: Actinomyces naeslundii has been recovered from traumatized permanent teeth diagnosed with necrotic pulps. In this work, a triple antibiotic paste (TAP)-mimic scaffold is proposed as a drug-delivery strategy to eliminate A. naeslundii dentin biofilm. METHODS: Metronidazole, ciprofloxacin, and minocycline were added to a polydioxanone (PDS) polymer solution and spun into fibrous scaffolds. Fiber morphology, mechanical properties, and drug release were investigated by using scanning electron microscopy, microtensile testing, and high-performance liquid chromatography, respectively. Human dentin specimens (4 × 4 × 1 mm(3), n = 4/group) were inoculated with A. naeslundii (ATCC 43146) for 7 days for biofilm formation. The infected dentin specimens were exposed to TAP-mimic scaffolds, TAP solution (positive control), and pure PDS (drug-free scaffold). Dentin infected (7-day biofilm) specimens were used for comparison (negative control). Confocal laser scanning microscopy was done to determine bacterial viability. RESULTS: Scaffolds displayed a submicron mean fiber diameter (PDS = 689 ± 312 nm and TAP-mimic = 718 ± 125 nm). Overall, TAP-mimic scaffolds showed significantly (P ≤ .040) lower mechanical properties than PDS. Within the first 24 hours, a burst release for all drugs was seen. A sustained maintenance of metronidazole and ciprofloxacin was observed over 4 weeks, but not for minocycline. Confocal laser scanning microscopy demonstrated complete elimination of all viable bacteria exposed to the TAP solution. Meanwhile, TAP-mimic scaffolds led to a significant (P < .05) reduction in the percentage of viable bacteria compared with the negative control and PDS. CONCLUSIONS: Our findings suggest that TAP-mimic scaffolds hold significant potential in the eradication/elimination of bacterial biofilm, a critical step in regenerative endodontics.Item The antimicrobial efficacy of innovative 3D triple antibiotic paste-mimic tubular scaffold against actinomyces naeslundii(2015) Azabi, Asma Abulqasem; Bottino, Marco C.; Gregory, Richard L.; Spolnik, Kenneth J.; Cook, Norman Blaine, 1954-; Chu, Tien-Min GabrielBackground: Root canal disinfection is an essential requirement for the success of regenerative endodontics. Currently, the so-called triple antibiotic paste (TAP) is considered the standard of care. Notwithstanding the good antimicrobial capacity, the high concentration of TAP has shown significant toxicity to human cells, especially dental pulp stem cells. A novel drug release system, i.e., a triple antibiotic paste-mimic electrospun scaffold containing low concentrations of the antibiotics present in the TAP, has emerged as an effective and reliable alternative to fight root canal infections without potential toxic effects on dental stem cells, which are an integral part of the regenerative treatment. Objectives: The aim of this study was to determine the antimicrobial efficacy of an innovative three-dimensional (3D) triple antibiotic paste-mimic tubular scaffold against Actinomyces naeslundii biofilm formed inside human root canal dentinal tubules. Materials and methods: Pure polydioxanone (PDS) polymer solution and PDS loaded with metronidazole, ciprofloxacin and minocycline (35 wt.% of each antibiotic, 3D-TAP-mimic scaffold) were spun into 3D fibrous scaffolds. A. naeslundii (ATCC 43146) was centrifuged to induce biofilm formation inside human root canal dentinal tubules using a dentin slice model (1 mm thickness and 2.5 mm canal diameter). The infected dentin slices were exposed to the 3D-TAP-mimic scaffold, TAP solution (50 mg/mL of each antibiotic), and antibiotic-free PDS. Biofilm elimination was quantitatively and qualitatively analyzed by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM), respectively. Results: A dense penetration of A. naeslundii biofilm was observed by CLSM throughout the dentinal tubules. 3D-TAP-mimic scaffold significantly reduced the percentage of viable bacteria compared with PDS (p <.05). TAP solution completely eliminated viable bacteria without differing from 3D-TAP-mimic scaffolds. SEM images showed results similar to CLSM. Conclusion: Collectively, the proposed tubular 3D-TAP-mimic scaffold holds significant clinical potential for root canal disinfection strategy prior to regenerative endodontics.Item Antimicrobial Efficacy of Triple Antibiotic-Eluting Polymer Nanofibers against Multispecies Biofilm(Elsevier, 2017-09) Albuquerque, Maria T.P.; Nagata, Juliana; Bottino, Marco C.; Biomedical Sciences and Comprehensive Care, School of DentistryThe elimination of microbial flora in cases of immature permanent teeth with necrotic pulp is both key and a challenging goal for the long-term success of regenerative therapy. Recent research has focused on the development of cell-friendly intracanal drug delivery systems. This in vitro study aimed to investigate the antimicrobial action of 3-dimensional (3D) tubular-shaped triple antibiotic-eluting nanofibrous constructs against a multispecies biofilm on human dentin. Polydioxanone polymer solutions, antibiotic-free or incorporated with metronidazole, ciprofloxacin, and minocycline, were electrospun into 3D tubular-shaped constructs. A multispecies biofilm consisting of Actinomyces naeslundii, Streptococcus sanguinis, and Enterococcus faecalis was forced inside the dentinal tubules via centrifugation in a dentin slice in vitro model. The infected specimens were exposed to 2 experimental groups (ie, 3D tubular-shaped triple antibiotic-eluting constructs and triple antibiotic paste [TAP]) and 2 control groups (7-day biofilm untreated and antibiotic-free 3D tubular-shaped constructs). Biofilm elimination was quantitatively analyzed with confocal laser scanning microscopy. Confocal laser scanning microscopic (CLSM) analysis showed a dense population of viable (green) bacteria adhered to dentin and penetrated into the dentinal tubules. Upon 3D tubular-shaped triple antibiotic-eluting nanofibrous construct exposure, nearly complete elimination of viable bacteria on the dentin surface and inside the dentinal tubules was shown in the CLSM images, which was similar (P < .05) to the bacterial death promoted by the TAP group but significantly greater when compared with both the antibiotic-free 3D tubular-shaped constructs and the control (saline). The proposed 3D tubular-shaped antibiotic-eluting construct showed pronounced antimicrobial effects against the multispecies biofilm tested and therefore holds significant clinical potential as a disinfection strategy before regenerative endodontics.Item Antimicrobial properties of drug-containing electrospun scaffolds(2012) Jeppson, John; Spolnik, Kenneth Jacob, 1950-; Vail, Mychel Macapagal, 1969-; Erhlich, Ygal; Bottino, Marco C.; Gregory, Richard L.; Legan, Joseph J.; Zunt, Susan L., 1950-Endodontic treatment of the infected immature tooth has undergone a dramatic change. Conventional endodontic treatment can control infection, but root development usually remains impaired. A novel regenerative endodontic procedure, the revascularization method, can now control the infection and enable such teeth to continue root development. This is done by creating a fibrin-matrix scaffold in the antibiotic treated root canal space (RCS). Dental stem cells and growth factors have been able to continue root development in such an environment. The fibrin-matrix scaffold is dependent on the induction of a blood clot into the RCS, and this cannot always be predictably induced. PDS is a biocompatible material that can be electrospun to provide a matrix for cells and growth factors and perhaps improve on the blood clot induced fibrin scaffold by incorporating metronidazole as an adjuvant antimicrobial. A metronidazole containing electrospun PDS scaffold was examined in vitro using a turbidimetric test, the modified direct contact test. This scaffold significantly inhibited growth of an anaerobic primary endodontic pathogen Porphyromonas gingivalis. This scaffold may improve the treatment of the infected immature tooth by providing a designed matrix for root regeneration while serving simultaneously as an antibiotic drug delivery device to disinfect the RCS. The aim of this study is to evaluate in vitro the property of a synthetic scaffold to function as an antibacterial drug delivery device. PDS*II (polydioxanone) suture was obtained from Ethicon, INC. (Somerville, NJ) and was dissolved in 1,1,1,3,3,3-hexafluoro-2-propanol, HFIP (Sigma Aldrich). Three different scaffolds were electrospun onto an aluminum foil background; (1) control scaffold with no antibiotic incorporated, (2) scaffold with 5.0-wt % metronidazole incorporated, and (3) 25-wt % metronidazole incorporated. All scaffolds were cut using a 4-mm diameter biopsy punch under aseptic conditions and removed from foil, control scaffold (n = 64), scaffold containing 5.0-wt % metronidazole (n = 32), and scaffold containing 25-wt % metronidazole (n=32). Experimental scaffolds were placed in a 96- well sterile flat bottom microtiter plate. Porphyromonas gingivalis a known primary endodontic pathogen was grown in 5 ml of BHI + YE with 0.25 μl of vitamin K with incubation at 37°C under anaerobic conditions for 48 hours. Microplates were sterilized before inoculation with Pg with 400 μl of 70-percent EtOH for a minimum of 30 minutes then pipetted out. After sterilization the microwells were washed with 400 μl of sterile water and pipetted out. Group 1 (negative control) microwells (n = 8) contained control scaffold and 190 μl of broth only. Group 2 (positive control) microwells (n = 8) contained 190 μl of broth and Pg only. Group 3 microwells (n = 8) contained control scaffold, 190 μl of broth, and 10 μl of Pg inoculum. Group 4 microwells (n = 8) contained scaffold with 5 wt % metronidazole, 190 μl of broth, and 10 μl of Pg inoculum. Group 5 microwells (n = 8) contained scaffold with 25 wt % metronidazole, 190 μl of broth, and 10 μl of Pg inoculum. Group 6 contained 190 μl of uninoculated broth for spectrophotometer calibration. Sterile microplate lids were used to isolate microwells from the surrounding environment. Microplates were incubated at 37°C under anaerobic conditions for 48 hours. After 48 hours the microplates were read by using an endpoint reading in the spectrophotometer. This was repeated four times. Comparisons among the groups for differences in optical density as a measure of bacterial growth were made using mixed-model ANOVA, with a fixed effect for group and a random effect for experimental run. Pair-wise group comparisons were performed using Tukey's multiple comparisons procedure to control the overall significance level at 5 percent. The analyses were performed using the ranks of the data. Broth had significantly lower OD than all other groups (p < 0.0001). Broth+Pg and Broth+Pg+Scaffold had significantly higher OD than 5-wt % Metro (p < 0.0001) and 25-wt % Metro (p < 0.0001), but Broth+Pg and Broth+Pg+Scaffold were not significantly different from each other (p = 0.97). 5-wt % Metro and 25-wt % Metro were not significantly different from each other (p = 0.24). From the results of our study, we concluded that the 5.0-wt % and 25-wt % metronidazole containing scaffolds significantly inhibited bacterial growth and could be effectively utilized for the endodontic regeneration procedure.Item The Axolotl Fibula as a Model for the Induction of Regeneration across Large Segment Defects in Long Bones of the Extremities(Public Library of Science, 2015) Chen, Xiaoping; Song, Fengyu; Jhamb, Deepali; Li, Jiliang; Bottino, Marco C.; Palakal, Mathew J.; Stocum, David L.; Department of Biology, School of ScienceWe tested the ability of the axolotl (Ambystoma mexicanum) fibula to regenerate across segment defects of different size in the absence of intervention or after implant of a unique 8-braid pig small intestine submucosa (SIS) scaffold, with or without incorporated growth factor combinations or tissue protein extract. Fractures and defects of 10% and 20% of the total limb length regenerated well without any intervention, but 40% and 50% defects failed to regenerate after either simple removal of bone or implanting SIS scaffold alone. By contrast, scaffold soaked in the growth factor combination BMP-4/HGF or in protein extract of intact limb tissue promoted partial or extensive induction of cartilage and bone across 50% segment defects in 30%-33% of cases. These results show that BMP-4/HGF and intact tissue protein extract can promote the events required to induce cartilage and bone formation across a segment defect larger than critical size and that the long bones of axolotl limbs are an inexpensive model to screen soluble factors and natural and synthetic scaffolds for their efficacy in stimulating this process.Item Beam profile characterization of light-emitting-diode curing units and its effect on polymerization of a resin-matrix composite(2017) AlZain, Afnan Omar; Platt, Jeffrey A.; Chu, Tien-Min G.; Bottino, Marco C.; Hara, Anderson T.; Goodpaster, John V.; Roulet, Jean-FrancoisThe general aim of this study was to investigate the influence of the localized irradiance beam profiles from multiple light-emitting-diode (LED) light-curing units (LCUs) on the polymerization pattern within a resin-matrix composite (RMC). Irradiance beam profiles were generated from one quartz-tungsten-halogen and various single and multiple emission peak LED LCUs using a camera-based beam profiler system combined with LCU power measurements obtained using an integrating sphere/spectrometer assembly. The influence of distance on irradiance, radiant exposure (RE) and degree of conversion (DC) on the top and bottom surfaces of a RMC increment, using various LCUs, at two clinically relevant distances was investigated. Molar absorptivity of the photoinitiators present in the nano-hybrid RMC (Tetric EvoCeram bleaching shade-XL) assessed was using UV-spectrophotometry. The correlation among irradiance, RE and DC was explored. A mapping approach was used to investigate DC, microhardness and cross-link density (CLD) within 5×5×2 mm specimens at various depths; top, 0.5, 0.7, 0.9, 1.1, 1.3,1.5 mm and bottom. The localized irradiance correlation with its corresponding DC, microhardness and CLD was explored, and localized DC correlation with microhardness was assessed. The DC was measured using micro-Raman spectroscopy, and CLD was assessed by an ethanol-softening method (%KHN reduction) using an automated microhardness tester. Molar absorptivity of diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide was 20-fold higher than camphorquinone. Non-uniform LCU beam profiles caused localized polymerization discrepancies that were significant at specific depths and points within the specimens with respect to DC, microhardness and CLD, which did not follow a specific pattern regardless of the LCU or curing distance assessed. A moderate correlation was displayed among irradiance, RE and DC. The localized irradiance from the LCUs was weakly correlated with the corresponding DC, microhardness and CLD on the top surface of a RMC at both curing distances. The localized microhardness was moderately correlated with DC. In conclusion, polymerization within the RMC investigated was non-uniform and did not reflect the LCU irradiance pattern at the area assessed. Also, a mapping approach within the specimens provided a detailed polymerization pattern assessment occurring within a RMC increment. Therefore, the LCUs explored may potentially increase the risk of RMC fracture.