Douglas Vieira Thomaz

Dr. Douglas Vieira Thomaz

., Frankfurt, Hesse, Germany
orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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29 June 2023 in International Journal of Oral Science
Verified
Journal Article
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Paola DongiovanniPaola Dongiovanni
Paola Dongiovanni
MMMarica Meroni
Marica Meroni
SCSara Casati
Sara Casati
RGRiccardo Goldoni
Riccardo Goldoni
Douglas Vieira ThomazDouglas Vieira Thomaz
Douglas Vieira Thomaz
GTGianluca M. Tartaglia
Gianluca M. Tartaglia
Several chronic disorders including type 2 diabetes (T2D), obesity, heart disease and cancer are preceded by a state of chronic low-grade inflammation. Biomarkers for the early assessment of chronic disorders encompass acute phase proteins (APP), cytokines and chemokines, pro-inflammatory enzymes, lipids and oxidative stress mediators. These substances enter saliva through the blood flow and, in some cases, there is a close relation between their salivary and serum concentration. Saliva can be easily collected and stored with non-invasive and cost-saving procedures, and it is emerging the concept to use it for the detection of inflammatory biomarkers. To this purpose, the present review aims to discuss the advantages and challenges of using standard and cutting-edge techniques to discover salivary biomarkers which may be used in diagnosis/therapy of several chronic diseases with inflammatory consequences with the pursuit to possibly replace conventional paths with detectable soluble mediators in saliva. Specifically, the review describes the procedures used for saliva collection, the standard approaches for the measurement of salivary biomarkers and the novel methodological strategies such as biosensors to improve the quality of care for chronically affected patients.

1 September 2022 in Polymers
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EBElisa Brambilla
Elisa Brambilla
SLSilvia Alice Locarno
Silvia Alice Locarno
Salvatore GalloSalvatore Gallo
Salvatore Gallo
FOFrancesco Orsini
Francesco Orsini
CPCarolina Pini
Carolina Pini
Gianluca TartagliaGianluca Tartaglia
Gianluca Tartaglia
Thermogelling amphiphilic block copolymers have been widely investigated in the development of pharmaceutical drug carriers. In particular, thermosensitive gels based on poloxamer 407 (P407) have great potential for periodontal disease treatment, thanks to their ability to be liquid at room temperature and become viscous gels at body temperature. However, some problems, related to short in situ residence time, reduce their feasible clinical use. Thus, in order to improve the effective applicability of these materials, we studied how P407 thermogels are affected by the pH and by the inclusion of different hydrophilic polymers, used as excipients for increasing the gel stiffness. For this scope, a complete chemical-physical characterization of the synthesized gels is provided, in terms of determination of sol-gel transition temperature, viscosity and erosion degree. The data are correlated according to a statistical multivariate approach based on Principal Component Analysis and their mucoadhesion properties are also tested by Tapping mode-Atomic Force Microscopy (TM-AFM) imaging. Finally, we studied how the different P407 formulations are able to influence the release pathway of two antibacterial drugs (i.e., chlorhexidine digluconate and doxycycline hyclate) largely used in oral diseases.

1 May 2018 in Revista Brasileira de Farmacognosia
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Journal Article
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KLKarla Carneiro de Siqueira Leite
Karla Carneiro de Siqueira Leite
LGLuane Ferreira Garcia
Luane Ferreira Garcia
GLGermán Sanz Lobón
Germán Sanz Lobón
Douglas Vieira ThomazDouglas Vieira Thomaz
Douglas Vieira Thomaz
EMEmily Kussmaul Gonçalves Moreno
Emily Kussmaul Gonçalves Moreno
EGEric Gil
Eric Gil
The prevention of chronic and degenerative diseases, is a health concern deeply associated with oxidative stress. Such progressive phenomena can be avoided through exogenous antioxidant intake, which set up a reductant cascade, mopping up damaging free radicals. Medicinal herbs are commonly associated with high antioxidant potential, and hence their health benefits. The commerce of dried herbal extracts movements a big portion of developing countries economy. The determination of medicinal herbs the antioxidant activity capacity is of utmost importance. The assessment of antioxidant activity in phytotherapics is mostly achieved by spectrophotometric assays, however colored substances can produce interferences that do not occur in electroanalytical methods. Therefore, the aim of this paper is to compare spectrophotometric and voltammetric techniques to evaluate antioxidant activity in herbal drugs such as: Ginkgo biloba L., Camellia sinensis (L.) Kuntze, Theaceae; Hypericum perforatum L., Hypericaceae; Aesculus hippocastanum L., Sapindaceae; Rosmarinus officinalis L., Lamiaceae; Morinda citrifolia L., Rubiaceae; Centella asiatica (L.) Urb., Apiaceae; Trifolium pratense L., Fabaceae; Crataegus oxyacantha L., Rosaceae; and Vaccinium macrocarpon Aiton, Ericaceae. The spectrophotometric methods employed were DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) and the Folin-Ciocalteu assays. The electroanalytical method used was voltammetry and it was developed a phenoloxidase based biosensor. The redox behavior observed for each herbal sample resulted in distinguishable voltammetric profiles. The highest electrochemical indexes were found to G. biloba and H. perforatum, corroborating to traditional spectrophotometric methods. Thus, the electroanalysis of herbal drugs, may be a promising tool for antioxidant potential assessment.

1 February 2020 in Food Hydrocolloids
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Journal Article
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RBRayssa Dias Batista
Rayssa Dias Batista
DMDianiny de Cássia Sousa Mendes
Dianiny de Cássia Sousa Mendes
CMCleiber Cintra Morais
Cleiber Cintra Morais
Douglas Vieira ThomazDouglas Vieira Thomaz
Douglas Vieira Thomaz
DADiego Palmiro Ramirez Ascheri
Diego Palmiro Ramirez Ascheri
EAEduardo Ramirez Asquieri
Eduardo Ramirez Asquieri

1 January 2018 in Oxidative Medicine and Cellular Longevity
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TOThiago Sardinha de Oliveira
Thiago Sardinha de Oliveira
Douglas Vieira ThomazDouglas Vieira Thomaz
Douglas Vieira Thomaz
HNHiasmin Franciely da Silva Neri
Hiasmin Franciely da Silva Neri
LCLetícia Bonancio Cerqueira
Letícia Bonancio Cerqueira
LGLuane Ferreira Garcia
Luane Ferreira Garcia
PGPaulo César Ghedini
Paulo César Ghedini
Pequi (Caryocar brasiliense) is an endemic species from Brazilian Cerrado, and their fruits are widely used in regional cuisine. In this work, a crude hydroalcoholic extract (CHE) of C. brasiliense leaves and its resulting fractions in hexane (HF), chloroform (CF), ethyl acetate (EAF), and butanol (BF) were investigated for their antioxidant properties and anticholinesterase activities. The antioxidant properties were evaluated by free radical scavenging and electroanalytical assays, which were further correlated with the total phenolic content and LC‐MS results. The acetylcholinesterase and butyrylcholinesterase inhibitory activities were examined using Ellman’s colorimetric method. The LC‐MS analysis of EAF revealed the presence of gallic acid and quercetin. CHE and its fractions, EAF and BF, showed anticholinesterase and antioxidant activities, suggesting the association of both effects with the phenolic content. In addition, behavioral tests performed with CHE (10, 100, and 300 mg/kg) showed that it prevented mice memory impairment which resulted from aluminium intake. Moreover, CHE inhibited brain lipid peroxidation and acetyl and butyryl‐cholinesterase activities and the extract’s neuroprotective effect was reflected at the microscopic level. Therefore, the leaves of pequi are a potential source of phenolic antioxidants and can be potentially used in treatments of memory dysfunctions, such as those associated with neurodegenerative disorders.

8 February 2019 in Preparative Biochemistry & Biotechnology
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Journal Article
Closed access
LGLuane Ferreira Garcia
Luane Ferreira Garcia
MLMonike Fabiane Alves Ribeiro Lacerda
Monike Fabiane Alves Ribeiro Lacerda
Douglas Vieira ThomazDouglas Vieira Thomaz
Douglas Vieira Thomaz
JGJhéssica Cavalcante de Souza Golveia
Jhéssica Cavalcante de Souza Golveia
MPMaria das Graças Cabral Pereira
Maria das Graças Cabral Pereira
MSMariângela Fontes Santiago
Mariângela Fontes Santiago
Laccase extract (LE) from Pycnoporus sanguineus was immobilized on calcium and copper alginate–chitosan beads and applied for the removal of 17α-ethinylestradiol (EE2). Effects of immobilization conditions such as: sodium alginate (SA) concentration; LE/SA ratio and chitosan/ion (Ca+2 or Cu+2) ratio on the immobilization yield were investigated. Immobilized LE on Ca-beads and Cu-beads was then used to degrade an EE2 solution. The optimal conditions for LE immobilization on Ca-beads were: 1.5% (w/v) SA, 1:5 (v/v) LE/SA and 3:7 (v/v) chitosan/ion (Ca+2). The optimal conditions for immobilization on Cu-beads were 2.0% (w/v) SA, 0.5:5 (v/v) LE/SA and 3:7 (v/v) chitosan/ion (Cu+2). The best result was obtained for immobilized LE on Ca-beads in buffer-absent medium. Furthermore, the immobilized enzyme was reused in five cycles for EE2 removal. The formation of EE2 dimers by LE treatment has been demonstrated by electrospray ionization coupled to time of flight mass spectrometer (ESI–TOF–MS). The results evidenced that immobilized LE in alginate–chitosan–divalent cation bead is an effective alternative for EE2 removal.