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Gil ACK, Prado MM, Rocha LRD, Benfatti C, Schuldt Filho G, Almeida JD. In vitro evaluation of membranes for regenerative procedures against oral bacteria. Braz Dent J 2023; 34:57-65. [PMID: 37466526 PMCID: PMC10355258 DOI: 10.1590/0103-6440202305060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Accepted: 03/20/2023] [Indexed: 07/20/2023] Open
Abstract
The current literature on guided bone regeneration (GBR) and guided tissue regeneration (GTR) membrane contamination reports that the physicochemical characteristics of these biomaterials might influence affinity to bacteria, which appears to be a major drawback for the clinical outcome of the regenerative procedures. Thus, this study aimed to evaluate, in vitro, a multispecies biofilm adherence and passage of bacteria through different types of commercially available membranes for GTR/GBR. Four types of membranes were tested (n=12): LC) Lumina Coat®; JS) Jason®; BG) Biogide®; and LP) Lumina PTFE®. Aluminum foil (AL) simulated an impermeable barrier and was used as the control. The membranes were adapted to specific apparatus and challenged with a mixed bacterial culture composed of A. actinomycetemcomitans b, S. mutans, S. mitis, and A. israelii. After 2 h or 7 days, bacterial adhesion and passage of bacteria were evaluated through CFU counting, which was analyzed by two-way ANOVA e post hoc Tukey, at a 5% significance level. Representative areas of two membranes of each group were analyzed through scanning electron microscopy (SEM) to assess the morphology and organization of the biofilm over the membrane fibers. LC and LP presented similar values of adhered bacterial cells (p > 0.05), significantly inferior when compared to the other groups, in both time points (p < 0.05). All the tested groups were permeable to bacterial cells, with no significant difference between the trial period of 2 h and 7 days (p > 0.05). SEM analyses demonstrated that adhered bacteria number increased throughout the time points (2 h < 7 days). Commercially available biological membranes demonstrated intense bacterial adherence and passage of bacteria, which increased throughout the trial period.
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Affiliation(s)
- Ana Clara Kuerten Gil
- Department of Implant Dentistry, Federal University of Santa Catarina (UFSC), Florianópolis, Santa Catarina, Brazil
| | - Maick Meneguzzo Prado
- Department of Chemical Engineering, Federal University of Santa Catarina (UFSC), Florianópolis, Santa Catarina, Brazil
| | - Laura Rhoden da Rocha
- Department of Endodontics, University of Southern Santa Catarina (UNISUL), Palhoça, Santa Catarina, Brazil
| | - César Benfatti
- Department of Implant Dentistry, Federal University of Santa Catarina (UFSC), Florianópolis, Santa Catarina, Brazil
| | - Guenther Schuldt Filho
- Department of Implant Dentistry, University of Southern Santa Catarina (UNISUL), Palhoça, Santa Catarina, Brazil
| | - Josiane de Almeida
- Department of Endodontics, University of Southern Santa Catarina (UNISUL), Palhoça, Santa Catarina, Brazil
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Kichler V, Teixeira LS, Prado MM, Colla G, Schuldt DPV, Coelho BS, Porto LM, de Almeida J. A novel antimicrobial-containing nanocellulose scaffold for regenerative endodontics. Restor Dent Endod 2021; 46:e20. [PMID: 34123756 PMCID: PMC8170374 DOI: 10.5395/rde.2021.46.e20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Accepted: 09/23/2020] [Indexed: 11/11/2022] Open
Abstract
Objectives The aim of this study was to evaluate bacterial nanocellulose (BNC) membranes incorporated with antimicrobial agents regarding cytotoxicity in fibroblasts of the periodontal ligament (PDLF), antimicrobial activity, and inhibition of multispecies biofilm formation. Materials and Methods The tested BNC membranes were BNC + 1% clindamycin (BNC/CLI); BNC + 0.12% chlorhexidine (BNC/CHX); BNC + nitric oxide (BNC/NO); and conventional BNC (BNC; control). After PDLF culture, the BNC membranes were positioned in the wells and maintained for 24 hours. Cell viability was then evaluated using the MTS calorimetric test. Antimicrobial activity against Enterococcus faecalis, Actinomyces naeslundii, and Streptococcus sanguinis (S. sanguinis) was evaluated using the agar diffusion test. To assess the antibiofilm activity, BNC membranes were exposed for 24 hours to the mixed culture. After sonicating the BNC membranes to remove the remaining biofilm and plating the suspension on agar, the number of colony-forming units (CFU)/mL was determined. Data were analyzed by 1-way analysis of variance and the Tukey, Kruskal-Wallis, and Dunn tests (α = 5%). Results PDLF metabolic activity after contact with BNC/CHX, BNC/CLI, and BNC/NO was 35%, 61% and 97%, respectively, compared to BNC. BNC/NO showed biocompatibility similar to that of BNC (p = 0.78). BNC/CLI showed the largest inhibition halos, and was superior to the other BNC membranes against S. sanguinis (p < 0.05). The experimental BNC membranes inhibited biofilm formation, with about a 3-fold log CFU reduction compared to BNC (p < 0.05). Conclusions BNC/NO showed excellent biocompatibility and inhibited multispecies biofilm formation, similarly to BNC/CLI and BNC/CHX.
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Affiliation(s)
- Victoria Kichler
- Department of Endodontics, Faculty of Dentistry, University of Southern Santa Catarina, Palhoça, SC, Brazil
| | - Lucas Soares Teixeira
- Department of Endodontics, Faculty of Dentistry, University of Southern Santa Catarina, Palhoça, SC, Brazil
| | - Maick Meneguzzo Prado
- Department of Chemical Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Guilherme Colla
- Department of Chemical Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | | | - Beatriz Serrato Coelho
- Department of Endodontics, Faculty of Dentistry, University of Southern Santa Catarina, Palhoça, SC, Brazil
| | - Luismar Marques Porto
- Department of Chemical Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Josiane de Almeida
- Department of Endodontics, Faculty of Dentistry, University of Southern Santa Catarina, Palhoça, SC, Brazil.,Department of Chemical Engineering, Federal University of Santa Catarina, Florianópolis, SC, Brazil
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Prado MM, Kovalski DJ, Torrez WB, Bueno-Silva B, Feres M, de Almeida J, Porto LM. Development of a multispecies periodontal biofilm model within a stirred bioreactor. Biofouling 2020; 36:725-735. [PMID: 32781835 DOI: 10.1080/08927014.2020.1805600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/18/2020] [Accepted: 07/28/2020] [Indexed: 06/11/2023]
Abstract
The objective of this work was to develop a subgingival biofilm model using a stirred bioreactor. Discs of bovine teeth were adapted to a stirred bioreactor filled with a culture medium containing bacterial species associated with periodontal health or disease. After anaerobic incubation, the biofilms growing on the substratum surfaces were collected and analyzed. The mean number of Colony-forming Units (CFUs) varied, but with no difference between 3 and 7 days of biofilm formation (p > 0.05). Scanning Electron Microscopy (SEM) analysis showed a uniform biofilm layer covering the cement layer of the root surface containing bacteria with diverse morphology. In checkerboard DNA-DNA hybridization, bacterial species were identified in both biofilms. In conclusion, a subgingival biofilm model was developed using a stirred bioreactor, allowing the in vitro reproduction of complex microbial communities. This is an advanced model that may be useful to mimic complex clinical periodontal biofilms.
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Affiliation(s)
- Maick Meneguzzo Prado
- LiEB - Integrated Laboratory of Biological Engineering, Chemical and Food Engineering Department, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - Davi J Kovalski
- LiEB - Integrated Laboratory of Biological Engineering, Chemical and Food Engineering Department, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | | | - Bruno Bueno-Silva
- Dental Research Division, Guarulhos University, Guarulhos, SP, Brazil
| | - Magda Feres
- Dental Research Division, Guarulhos University, Guarulhos, SP, Brazil
| | - Josiane de Almeida
- LiEB - Integrated Laboratory of Biological Engineering, Chemical and Food Engineering Department, Federal University of Santa Catarina, Florianópolis, SC, Brazil
- Faculty of Dentistry, Department of Endodontics, University of Southern Santa Catarina, Palhoça, SC, Brazil
| | - Luismar M Porto
- LiEB - Integrated Laboratory of Biological Engineering, Chemical and Food Engineering Department, Federal University of Santa Catarina, Florianópolis, SC, Brazil
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Thewes S, Prado-Cabrero A, Prado MM, Tudzynski B, Avalos J. Characterization of a gene in the car cluster of Fusarium fujikuroi that codes for a protein of the carotenoid oxygenase family. Mol Genet Genomics 2005; 274:217-28. [PMID: 16049681 DOI: 10.1007/s00438-005-0015-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2004] [Accepted: 05/19/2005] [Indexed: 10/25/2022]
Abstract
The ascomycete Fusarium fujikuroi produces carotenoids by means of the enzymes encoded by three car genes. The enzymes encoded by carRA and carB are responsible of the synthesis of beta-carotene and torulene, respectively, while the product encoded by carT cleaves torulene to produce the acidic xanthophyll neurosporaxanthin. carRA and carB are found in a cluster with a third gene, carO, which codes for an opsin-like protein. However, no information is available on the sequence or chromosomal location of carT, which has been identified only by mutant analysis. Transcription of the three clustered genes is stimulated by light and by mutations in a regulatory gene, leading to overproduction of carotenoids. We have now identified a fourth gene in the car cluster, called carX, which codes for a protein similar to known carotenoid-cleaving oxygenases. carX is transcribed divergently from carRA, and exhibits the same transcriptional pattern as carRA, carB and carO. Targeted deletion of carX resulted in a phenotype characterized by a significant increase in the overall carotenoid content. In the dark, the carX mutants accumulate at least five times more carotenoids than the wild type, and exhibit partial derepression of carRA and carB transcription. The mutants also show more intense pigmentation in the light, but the increase in the carotenoid content relative to the wild type is less than twofold. Under these conditions, the mutants also show a relative increase in the amounts of phytoene and cyclic carotenoids formed, suggesting that CarRA activity is enhanced.
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Affiliation(s)
- S Thewes
- Institut für Botanik, Westfalische Wilhelms-Universität, Münster, Germany
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Linnemannstöns P, Prado MM, Fernández-Martín R, Tudzynski B, Avalos J. A carotenoid biosynthesis gene cluster in Fusarium fujikuroi: the genes carB and carRA. Mol Genet Genomics 2002; 267:593-602. [PMID: 12172798 DOI: 10.1007/s00438-002-0690-5] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2002] [Accepted: 05/01/2002] [Indexed: 10/27/2022]
Abstract
Phytoene synthase, phytoene dehydrogenase and carotene cyclase are three of the four enzyme activities needed to produce the acidic carotenoid neurosporaxanthin from the precursor geranylgeranyl pyrophosphate. In the filamentous fungus Fusarium fujikuroi, these three enzyme activities are encoded by two closely linked genes, carRA and carB, oriented in the same direction in the genome. The two genes are separated by 548 bp and code for two polypeptides of 612 and 541 amino acids, respectively, which are highly similar to the homologous proteins from other filamentous fungi. The ORF of carRA contains a 96-bp insertion that is absent in the other fungal homologues. The 32 additional residues are located in one of the two repeated domains responsible for the cyclase activity in the homologous fungal proteins. We have determined the function of carRA by gene disruption. The resulting mutants were albino and had lost the ability to produce phytoene, as expected from the simultaneous loss of phytoene synthase and carotene cyclase. In the same experiments, we also found transformants in which carB had been deleted. These mutants accumulate phytoene, confirming the function of the gene previously shown by gene-targeted mutagenesis. Expression of carRA and carB is strongly induced by light. Loss of carB or disruption of the carRA ORF led to enhanced expression of the carRA gene, suggesting the existence of a feedback regulatory mechanism.
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Affiliation(s)
- P Linnemannstöns
- Institut für Botanik, Westfalische Wilhelms-Universität, Schlossgarten 3, D-48149 Münster, Germany
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Affiliation(s)
- S S Sánchez
- Departamento de Biología del Desarrollo, INSIBIO (CONICET-UNT), Chacabuco 461, 4000-San Miguel de Tucumán, Tucumán, Argentina.
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Abstract
This study is a critical reflection on attempts to alter the Declaration of Helsinki, a key document of the democratic theses achieved in the latter half of the 20th century and thus a legacy for humanity because of its ethical guidelines for research involving human beings. Therefore, there must be worldwide social control over such a document, and any change in it demands ample debate with international participation to avoid any reversal in its humanitarian thrust. The study analyzes current aspects of research with human subjects in so-called "outlying" or "developing" countries. It also brings a social and political focus to the matter, highlighting that the economic fundamentalism exercised by wealthy countries inevitably leads to an ethical imperialism, exposing communities of poor countries to even greater vulnerability, discrimination, and social exclusion.
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Affiliation(s)
- V Garrafa
- Núcleo de Estudos e Pesquisas em Bioética, Centro de Estudos Avançados Multidisciplinares, Universidade de Brasília, Brasília, DF, 70910-900, Brasil
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