Browsing by Subject "Nanofibers"
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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 Bioactive nanofibrous scaffolds for regenerative endodontics(SAGE, 2013-11) Bottino, M.C.; Kamocki, K.; Yassen, G.H.; Platt, J.A.; Vail, M.M.; Ehrlich, Y.; Spolnik, K.J.; Gregory, R.L.; Endodontics, School of DentistryHere we report the synthesis, materials characterization, antimicrobial capacity, and cytocompatibility of novel antibiotic-containing scaffolds. Metronidazole (MET) or Ciprofloxacin/(CIP) was mixed with a polydioxanone (PDS)polymer solution at 5 and 25 wt% and processed into fibers. PDS fibers served as a control. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), tensile testing, and high-performance liquid chromatography (HPLC) were used to assess fiber morphology, chemical structure, mechanical properties, and drug release, respectively. Antimicrobial properties were evaluated against those of Porphyromonas gingivalis/Pg and Enterococcus faecalis/Ef. Cytotoxicity was assessed in human dental pulp stem cells (hDPSCs). Statistics were performed, and significance was set at the 5% level. SEM imaging revealed a submicron fiber diameter. FTIR confirmed antibiotic incorporation. The tensile values of hydrated 25 wt% CIP scaffold were significantly lower than those of all other groups. Analysis of HPLC data confirmed gradual, sustained drug release from the scaffolds over 48 hrs. CIP-containing scaffolds significantly (p < .00001) inhibited biofilm growth of both bacteria. Conversely, MET-containing scaffolds inhibited only Pg growth. Agar diffusion confirmed the antimicrobial properties against specific bacteria for the antibiotic-containing scaffolds. Only the 25 wt% CIP-containing scaffolds were cytotoxic. Collectively, this study suggests that polymer-based antibiotic-containing electrospun scaffolds could function as a biologically safe antimicrobial drug delivery system for regenerative endodontics.Item Biodegradable nanofibrous drug delivery systems: effects of metronidazole and ciprofloxacin on periodontopathogens and commensal oral bacteria(Springer-Verlag, 2014-12) Bottino, Marco C.; Arthur, Rodrigo A.; Waeiss, R. Aaron; Kamocki, Krzysztof; Gregson, Karen S.; Gregory, Richard L.; Department of Restorative Dentistry, IU School of DentistryOBJECTIVES: The purposes of this study were to fabricate biodegradable polydioxanone (PDS II®) electrospun periodontal drug delivery systems (hereafter referred to as matrices) containing either metronidazole (MET) or ciprofloxacin (CIP) and to investigate the effects of antibiotic incorporation on both periodontopathogens and commensal oral bacteria. MATERIALS AND METHODS: Fibrous matrices were processed from PDS polymer solution by electrospinning. Antibiotic-containing PDS solutions were prepared to obtain four distinct groups: 5 wt.% MET, 25 wt.% MET, 5 wt.% CIP, and 25 wt.% CIP. Pure PDS was used as a control. High-performance liquid chromatography (HPLC) was done to evaluate MET and CIP release. Dual-species biofilms formed by Lactobacillus casei (Lc) and Streptococcus salivarius (Ss) were grown on the surface of all electrospun matrices. After 4 days of biofilm growth, the viability of bacteria on biofilms was assessed. Additionally, antimicrobial properties were evaluated against periodontopathogens Fusobacterium nucleatum (Fn) and Aggregatibacter actinomycetemcomitans (Aa) using agar diffusion assay. RESULTS: A three-dimensional interconnected porous network was observed in the different fabricated matrices. Pure PDS showed the highest fiber diameter mean (1,158 ± 402 nm) followed in a descending order by groups 5 wt.% MET (1,108 ± 383 nm), 25 wt.% MET (944 ± 392 nm), 5 wt.% CIP (871 ± 309 nm), and 25 wt.% CIP (765 ± 288 nm). HPLC demonstrated that groups containing higher amounts (25 wt.%) of incorporated drugs released more over time, while those with lower levels (5 wt.%) the least. No inhibitory effect of the tested antibiotics was detected on biofilm formation by the tested commensal oral bacteria. Meanwhile, CIP-containing matrices inhibited growth of Fn and Aa. CONCLUSION: CIP-containing matrices led to a significant inhibition of periodontopathogens without negatively impairing the growth of periodontal beneficial bacteria. CLINICAL RELEVANCE: Based on the proven in vitro inhibition of periodontitis-related bacteria, future in vivo research using relevant animal models is needed to confirm the effectiveness of these drug delivery systems.Item Clindamycin-modified Triple Antibiotic Nanofibers: A Stain-free Antimicrobial Intracanal Drug Delivery System(Elsevier, 2018-01) Karczewski, Ashley; Feitosa, Sabrina A.; Hamer, Ethan I.; Pankajakshan, Divya; Gregory, Richard L.; Spolnik, Kenneth J.; Bottino, Marco C.; Biomedical Sciences and Comprehensive Care, School of DentistryINTRODUCTION: A biocompatible strategy to promote bacterial eradication within the root canal system after pulpal necrosis of immature permanent teeth is critical to the success of regenerative endodontic procedures. This study sought to synthesize clindamycin-modified triple antibiotic (metronidazole, ciprofloxacin, and clindamycin [CLIN]) polymer (polydioxanone [PDS]) nanofibers and determine in vitro their antimicrobial properties, cell compatibility, and dentin discoloration. METHODS: CLIN-only and triple antibiotic CLIN-modified (CLIN-m, minocycline-free) nanofibers were processed via electrospinning. Scanning electron microscopy, Fourier-transform infrared spectroscopy (FTIR), and tensile testing were performed to investigate fiber morphology, antibiotic incorporation, and mechanical strength, respectively. Antimicrobial properties of CLIN-only and CLIN-m nanofibers were assessed against several bacterial species by direct nanofiber/bacteria contact and over time based on aliquot collection up to 21 days. Cytocompatibility was measured against human dental pulp stem cells. Dentin discoloration upon nanofiber exposure was qualitatively recorded over time. The data were statistically analyzed (P < .05). RESULTS: The mean fiber diameter of CLIN-containing nanofibers ranged between 352 ± 128 nm and 349 ± 128 nm and was significantly smaller than PDS fibers. FTIR analysis confirmed the presence of antibiotics in the nanofibers. Hydrated CLIN-m nanofibers showed similar tensile strength to antibiotic-free (PDS) nanofibers. All CLIN-containing nanofibers and aliquots demonstrated pronounced antimicrobial activity against all bacteria. Antibiotic-containing aliquots led to a slight reduction in dental pulp stem cell viability but were not considered toxic. No visible dentin discoloration upon CLIN-containing nanofiber exposure was observed. CONCLUSIONS: Collectively, based on the remarkable antimicrobial effects, cell-friendly, and stain-free properties, our data suggest that CLIN-m triple antibiotic nanofibers might be a viable alternative to minocycline-based antibiotic pastes.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 DESIGN AND FABRICATION OF MULTI-FUNCTIONAL ENERGY STORAGE COMPOSITES INTEGRATING ULTRATHIN LITHIUM-ION BATTERY WITH ENHANCED ELECTRO-MECHANICAL PERFORMANCE(EPFL Lausanne, Composite Construction Laboratory, 2022-06) Biswas, Pias Kumar; Jadhav, Mayur; Ananda Habarakada Liyanage, Asel; Dalir, Hamid; Agarwal, MangilalExponential advancement in the automotive and aerospace industry promotes the need for Multifunctional Energy Storage Composites (MESCs) to minimize the dependence on fossil fuels and reduce structural weight. This study proposes and evaluates a multi-functional carbon fiber reinforced polymer (CFRP) composite with an embedded lithium-ion polymer battery, demonstrating a structural integrity concept. Here electrospun epoxy-multiwalled carbon nanotubes (epoxy-MWCNT) nanofibers were incorporated precisely on the uncured CFRP surface to enhance adequate interfacial bonding and adhesion between the layers after curing. The mechanical and physical properties of modified CFRP have been evidenced to possess higher mechanical strength than the traditional CFRP composite. Commercial ultra-thin lithium-ion battery with higher energy density has been uniquely integrated into the core of the CFRP composite structure. Comparison with conventional CFRP composite and electro-mechanical testing ensured that the electrochemical property of the embedded battery was preserved in loading/unloading conditions, and the mechanical strength of the composite structure was not compromised.Item Electrospun Nanofibers for Label-Free Sensor Applications(MDPI, 2019-08-17) Aliheidari, Nahal; Aliahmad, Nojan; Agarwal, Mangilal; Dalir, Hamid; Engineering Technology, School of Engineering and TechnologyElectrospinning is a simple, low-cost and versatile method for fabricating submicron and nano size fibers. Due to their large surface area, high aspect ratio and porous structure, electrospun nanofibers can be employed in wide range of applications. Biomedical, environmental, protective clothing and sensors are just few. The latter has attracted a great deal of attention, because for biosensor application, nanofibers have several advantages over traditional sensors, including a high surface-to-volume ratio and ease of functionalization. This review provides a short overview of several electrospun nanofibers applications, with an emphasis on biosensor applications. With respect to this area, focus is placed on label-free sensors, pertaining to both recent advances and fundamental research. Here, label-free sensor properties of sensitivity, selectivity, and detection are critically evaluated. Current challenges in this area and prospective future work is also discussed.