Browsing by Subject "Scaffold"
Now showing 1 - 9 of 9
Results Per Page
Sort Options
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 Dental pulp stem cell responses to novel antibiotic-containing scaffolds for regenerative endodontics(Wiley, 2015-12) Kamocki, K.; Nör, J. E.; Bottino, M. C.; Department of Restorative Dentistry, IU School of DentistryAIM: To evaluate both the drug-release profile and the effects on human dental pulp stem cells' (hDPSC) proliferation and viability of novel bi-mix antibiotic-containing scaffolds intended for use as a drug delivery system for root canal disinfection prior to regenerative endodontics. METHODOLOGY: Polydioxanone (PDS)-based fibrous scaffolds containing both metronidazole (MET) and ciprofloxacin (CIP) at selected ratios were synthesized via electrospinning. Fibre diameter was evaluated based on scanning electron microscopy (SEM) images. Pure PDS scaffolds and a saturated CIP/MET solution (i.e. 50 mg of each antibiotic in 1 mL) (hereafter referred to as DAP) served as both negative (nontoxic) and positive (toxic) controls, respectively. High-performance liquid chromatography (HPLC) was performed to investigate the amount of drug(s) released from the scaffolds. WST-1(®) proliferation assay was used to evaluate the effect of the scaffolds on cell proliferation. LIVE/DEAD(®) assay was used to qualitatively assess cell viability. Data obtained from drug release and proliferation assays were statistically analysed at the 5% significance level. RESULTS: A burst release of CIP and MET was noted within the first 24 h, followed by a sustained maintenance of the drug(s) concentration for 14 days. A concentration-dependent trend was noticed upon hDPSCs' exposure to all CIP-containing scaffolds, where increasing the CIP concentration resulted in reduced cell proliferation (P < 0.05) and viability. In groups exposed to pure MET or pure PDS scaffolds, no changes in proliferation were observed. CONCLUSIONS: Synthesized antibiotic-containing scaffolds had significantly lower effects on hDPSCs proliferation when compared to the saturated CIP/MET solution (DAP).Item Effects of Novel 3-dimensional Antibiotic-containing Electrospun Scaffolds on Dentin Discoloration(Elsevier, 2016-01) Porter, Margaret Louise A.; Münchow, Eliseu A.; Albuquerque, Maria T. P.; Spolnik, Kenneth J.; Hara, Anderson T.; Bottino, Marco C.; Department of Biomedical & Applied Sciences, IU School of DentistryINTRODUCTION: Although intracanal application of the triple antibiotic paste (TAP) may offer advantages (eg, disinfection), this practice has been associated with significant drawbacks, including tooth discoloration. In this study, the color change of dentin was monitored during treatment with distinct TAP pastes and novel tubular-shaped 3-dimensional electrospun scaffolds containing minocycline (MINO) or doxycycline (DOX). METHODS: Two TAP pastes (TAPMINO [MINO, metronidazole, and ciprofloxacin] and TAPDOX [DOX, metronidazole, and ciprofloxacin]), 4 scaffold-based groups containing MINO or DOX at distinct concentrations, 1 antibiotic-free scaffold, and 1 untreated group (control) were investigated. Human canines were sectioned at the cementoenamel junction and tubular-shaped scaffolds or paste were placed into the root canals and sealed. Color measurements (CIEL(*)a(*)b(*) parameters) were performed at baseline and after 1, 3, 7, 14, 21, and 28 days. Color changes were expressed as ΔE(*) values. In addition, scanning electron microscopy and energy-dispersive X-ray spectroscopy were also performed on the specimens after treatment. Data were analyzed using repeated measures analysis of variance (alpha = 0.05). RESULTS: All antibiotic-containing groups led to greater discoloration than the antibiotic-free groups. A severe discoloration occurred after 1 day. At the end of the experiment, antibiotic-treated samples exhibited crusts/agglomerates over the dentin surface, which totally or partially obliterated the dentinal tubules. The presence of MINO resulted in a greater color change than DOX. CONCLUSIONS: Scaffolds containing MINO or DOX produced similar color change to dentin when compared with their respective TAP systems, although DOX-related discoloration was less pronounced.Item Mineral deposition and vascular invasion of hydroxyapatite reinforced collagen scaffolds seeded with human adipose-derived stem cells(BMC, 2019-10-17) Weiss-Bilka, Holly E.; Meagher, Matthew J.; Gargac, Joshua A.; Niebur, Glen L.; Roeder, Ryan K.; Wagner, Diane R.; Mechanical Engineering and Energy, School of Engineering and TechnologyBackground: Collagen-based scaffolds reinforced with hydroxyapatite (HA) are an attractive choice for bone tissue engineering because their composition mimics that of bone. We previously reported the development of compression-molded collagen-HA scaffolds that exhibited high porosity, interconnected pores, and mechanical properties that were well-suited for surgical handling and fixation. The objective of this study was to investigate these novel collagen-HA scaffolds in combination with human adipose-derived stem cells (hASCs) as a template for bone formation in a subcutaneous athymic mouse model. Methods: Collagen-HA scaffolds and collagen-only scaffolds were fabricated as previously described, and a clinically approved bone void filler was used as a control for the material. Constructs were seeded with hASCs and were pre-treated with either control or osteogenic media. A cell-free group was also included. Scaffolds were implanted subcutaneously in the backs of athymic nude mice for 8 weeks. Mineral deposition was quantified via micro-computed tomography. Histological and immunofluorescence images of the explants were used to analyze their vascular invasion, remodeling and cellularity. Results: Cell-free collagen-HA scaffolds and those that were pre-seeded with osteogenically differentiated hASCs supported mineral deposition and vascular invasion at comparable rates, while cell-seeded constructs treated with the control medium showed lower mineralization after implantation. HA-reinforcement allowed collagen constructs to maintain their shape, provided improved cell-tissue-scaffold integration, and resulted in a more organized tissue when pre-treated in an osteogenic medium. Scaffold type and pre-treatment also determined osteoclast activity and therefore potential remodeling of the constructs. Conclusions: The results of this study cumulatively indicate that treatment medium and scaffold composition direct mineralization and angiogenic tissue formation in an ectopic model. The data suggest that it may be necessary to match the scaffold with a particular cell type and cell-specific pre-treatment to achieve optimal bone formation.Item Short Arrestin-3-Derived Peptides Activate JNK3 in Cells(MDPI, 2022-08-04) Perry-Hauser, Nicole A.; Kaoud, Tamer S.; Stoy, Henriette; Zhan, Xuanzhi; Chen, Qiuyan; Dalby, Kevin N.; Iverson, Tina M.; Gurevich, Vsevolod V.; Gurevich, Eugenia V.; Biochemistry and Molecular Biology, School of MedicineArrestins were first discovered as suppressors of G protein-mediated signaling by G protein-coupled receptors. It was later demonstrated that arrestins also initiate several signaling branches, including mitogen-activated protein kinase cascades. Arrestin-3-dependent activation of the JNK family can be recapitulated with peptide fragments, which are monofunctional elements distilled from this multi-functional arrestin protein. Here, we use maltose-binding protein fusions of arrestin-3-derived peptides to identify arrestin elements that bind kinases of the ASK1-MKK4/7-JNK3 cascade and the shortest peptide facilitating JNK signaling. We identified a 16-residue arrestin-3-derived peptide expressed as a Venus fusion that leads to activation of JNK3α2 in cells. The strength of the binding to the kinases does not correlate with peptide activity. The ASK1-MKK4/7-JNK3 cascade has been implicated in neuronal apoptosis. While inhibitors of MAP kinases exist, short peptides are the first small molecule tools that can activate MAP kinases.Item Stabilized collagen matrix dressing improves wound macrophage function and epithelialization(Federation of American Society of Experimental Biology, 2019-02) El Masry, Mohamed S.; Chaffee, Scott; Das Ghatak, Piya; Mathew-Steiner, Shomita S.; Das, Amitava; Higuita-Castro, Natalia; Roy, Sashwati; Anani, Raafat A.; Sen, Chandan K.; Surgery, School of MedicineDecellularized matrices of biologic tissue have performed well as wound care dressings. Extracellular matrix–based dressings are subject to rapid degradation by excessive protease activity at the wound environment. Stabilized, acellular, equine pericardial collagen matrix (sPCM) wound care dressing is flexible cross-linked proteolytic enzyme degradation resistant. sPCM was structurally characterized utilizing scanning electron and atomic force microscopy. In murine excisional wounds, sPCM was effective in mounting an acute inflammatory response. Postwound inflammation resolved rapidly, as indicated by elevated levels of IL-10, arginase-1, and VEGF, and lowering of IL-1β and TNF-α. sPCM induced antimicrobial proteins S100A9 and β-defensin-1 in keratinocytes. Adherence of Pseudomonas aeruginosa and Staphylococcus aureus on sPCM pre-exposed to host immune cells in vivo was inhibited. Excisional wounds dressed with sPCM showed complete closure at d 14, while control wounds remained open. sPCM accelerated wound re-epithelialization. sPCM not only accelerated wound closure but also improved the quality of healing by increased collagen deposition and maturation. Thus, sPCM is capable of presenting scaffold functionality during the course of wound healing. In addition to inducing endogenous antimicrobial defense systems, the dressing itself has properties that minimize biofilm formation. It mounts robust inflammation, a process that rapidly resolves, making way for wound healing to advance.—El Masry, M. S., Chaffee, S., Das Ghatak, P., Mathew-Steiner, S. S., Das, A., Higuita-Castro, N., Roy, S., Anani, R. A., Sen, C. K. Stabilized collagen matrix dressing improves wound macrophage function and epithelialization.