Georgios Konstantopoulos

Mr. Georgios Konstantopoulos

orcid

Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

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

Representative Publications

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12 January 2024 in Viruses
Verified
Journal Article
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GKGeorgios Konstantopoulos
Georgios Konstantopoulos
DLDanai Leventakou
Danai Leventakou
DSDespoina-Rozi Saltiel
Despoina-Rozi Saltiel
Efthalia ZervoudiEfthalia Zervoudi
Efthalia Zervoudi
ELEirini Logotheti
Eirini Logotheti
Christine KottaridiChristine Kottaridi
Christine Kottaridi
Human Papillomaviruses have been associated with the occurrence of cervical cancer, the fourth most common cancer that affects women globally, while 70% of cases are caused by infection with the high-risk types HPV16 and HPV18. The integration of these viruses’ oncogenes E6 and E7 into the host’s genome affects a multitude of cellular functions and alters the expression of molecules. The aim of this study was to investigate how these oncogenes contribute to the expression of immune system control molecules, using cell lines with integrated HPV16 genome, before and after knocking out E6 viral gene using the CRISPR/Cas9 system, delivered with a lentiviral vector. The molecules studied are the T-cell inactivating protein PD-L1, its transcription factor HIF-1a and the latter’s negative regulator, miR-143. According to our results, in the E6 knock out (E6KO) cell lines an increased expression of miR-143 was recorded, while a decrease in the expression of HIF-1a and PD-L1 was exhibited. These findings indicate that E6 protein probably plays a significant role in enabling cervical cancer cells to evade the immune system, while we propose a molecular pathway in cervical cancer, where PD-L1’s expression is regulated by E6 protein through a miR-143/HIF-1a axis.

22 September 2024 in Biomimetics
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Journal Article
Open access
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PMPanagiotis Manoudis
Panagiotis Manoudis
Ioannis ZuburtikudisIoannis Zuburtikudis
Ioannis Zuburtikudis
GKGeorgios Konstantopoulos
Georgios Konstantopoulos
HKHadil Abu Khalifeh
Hadil Abu Khalifeh
Christine KottaridiChristine Kottaridi
Christine Kottaridi
Ioannis KarapanagiotisIoannis Karapanagiotis
Ioannis Karapanagiotis
The erosion phenomena of the natural stone in cultural heritage are induced by various sources. Consequently, the development of multifunctional protective materials that combine two or more useful properties is an effective strategy in addressing the synergistic effects of various erosion mechanisms. A multifunctional coating, consisting of a silane-based precursor and zinc oxide (ZnO) nanoparticles (NPs), is produced and tested for the protection of limestone. The hybrid coating combines the following three properties: superhydrophobicity, including water-repellency, photocatalytic self-cleaning and biocidal activity. The relative concentration of the NPs (0.8% w/w), used for the suggested composite coating, is carefully selected according to wetting studies, colourimetric measurements and durability (tape peeling) tests. The non-wetting state is evidenced on the surface of the composite coating by the large contact angle of water drops (≈153°) and the small contact angle hysteresis (≈5°), which gives rise to a physical self-cleaning scenario (lotus effect). The photocatalytic chemical self-cleaning is shown with the removal of methylene blue, induced by UV-A radiation. Moreover, it is shown that the suggested coating hinders the incubation of E. coli and S. aureus, as the inhibitions are 94.8 and 99.9%, respectively. Finally, preliminary studies reveal the chemical stability of the suggested coating.

Verified
Journal Article
Open access
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IZIoannis Zygouras
Ioannis Zygouras
DLDanai Leventakou
Danai Leventakou
APAbraham Pouliakis
Abraham Pouliakis
SPStyliana Panagiotou
Styliana Panagiotou
DTDimitris Tsakogiannis
Dimitris Tsakogiannis
Christine KottaridiChristine Kottaridi
Christine Kottaridi
Persistent high-risk human papillomavirus (HPV) infection is a pivotal factor in the progression of cervical cancer. In recent years, an increasing interest has emerged in comprehending the influence of HPV on head and neck squamous cell carcinoma (HNSCC). Notably, it is well established that HPV-associated HNSCC show cases with distinct molecular and clinical attributes compared to HPV-negative cases. The present study delves into the epigenetic landscape of HPV16, specifically its L1 gene and untranslated region (UTR), through pyrosequencing, while the HPV16 DNA physical status was evaluated using E2/E6 ratio analysis in HPV16-positive HNSCC FFPE biopsies. Our findings reveal substantial methylation across six sites within the HPV16 L1 gene and seven sites in the UTR. Specifically, methylation percentages of two L1 CpG sites (7136, 7145) exhibit significant associations with tumor histological grade (p < 0.01), while proving concurrent methylation across multiple sites. The HPV16 DNA physical status was not correlated with the methylation of viral genome or tumor characteristics. This is the first study that examines epigenetic modifications and the HPV16 DNA physical status in Greek HNSCC patients. Our findings suggest an orchestrated epigenetic modulation among specific sites, impacting viral gene expression and intricate virus–host interactions.

29 October 2023 in Materials
Verified
Journal Article
Open access
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SPSotirios Pemas
Sotirios Pemas
Eleftheria XanthopoulouEleftheria Xanthopoulou
Eleftheria Xanthopoulou
Zoi TerzopoulouZoi Terzopoulou
Zoi Terzopoulou
GKGeorgios Konstantopoulos
Georgios Konstantopoulos
Dimitrios BikiarisDimitrios Bikiaris
Dimitrios Bikiaris
EPEleftheria Maria Pechlivani
Eleftheria Maria Pechlivani
Composite 3D printing filaments integrating antimicrobial nanoparticles offer inherent microbial resistance, mitigating contamination and infections. Developing antimicrobial 3D-printed plastics is crucial for tailoring medical solutions, such as implants, and cutting costs when compared with metal options. Furthermore, hospital sustainability can be enhanced via on-demand 3D printing of medical tools. A PLA-based filament incorporating 5% TiO2 nanoparticles and 2% Joncryl as a chain extender was formulated to offer antimicrobial properties. Comparative analysis encompassed PLA 2% Joncryl filament and a TiO2 coating for 3D-printed specimens, evaluating mechanical and thermal properties, as well as wettability and antimicrobial characteristics. The antibacterial capability of the filaments was explored after 3D printing against Gram-positive Staphylococcus aureus (S. aureus, ATCC 25923), as well as Gram-negative Escherichia coli (E. coli, ATCC 25922), and the filaments with 5 wt.% embedded TiO2 were found to reduce the viability of both bacteria. This research aims to provide the optimal approach for antimicrobial and medical 3D printing outcomes.

27 November 2024 in Journal of Medical Microbiology
Verified
Journal Article
Open access
Ioannis FragkioudakisIoannis Fragkioudakis
Ioannis Fragkioudakis
GKGeorgios Konstantopoulos
Georgios Konstantopoulos
Christine KottaridiChristine Kottaridi
Christine Kottaridi
ADAikaterini-Elisavet Doufexi
Aikaterini-Elisavet Doufexi
DSDimitra Sakellari
Dimitra Sakellari
Introduction. Peri-implantitis poses a significant challenge in oral health due to its complex microbial profile and biofilm-related persistence, complicating both prevention and treatment strategies. Hypothesis/Gap Statement. We hypothesized that biofilm formation by Candida albicans, Staphylococcus aureus and Staphylococcus epidermidis plays a critical role in peri-implantitis by inducing an inflammatory response, contributing to bone loss and implant failure. This study aimed to investigate the presence and quantify C. albicans, S. aureus and S. epidermidis in health and peri-implantitis using quantitative real-time PCR, enhancing our understanding of their roles in peri-implant disease. Aim: To explore the microbial burden of C. albicans, S. aureus, and S. epidermidis in peri-implantitis and healthy conditions, correlating these findings with clinical parameters. Methodology. In this cross-sectional study, 102 patients were recruited from the Department of Periodontology and Implant Biology at Aristotle University, Greece. Participants were divided into healthy/mucositis and peri-implantitis groups. Clinical parameters such as probing depth, clinical attachment levels and bleeding on probing were recorded, and microbiological samples were collected and analysed using real-time PCR, targeting specific genes for the pathogens. Results. Results showed that C. albicans was detected in 3.92 and S. aureus in 9.82% of samples, while S. epidermidis was present in all samples, with significantly higher loads in the peri-implantitis group (404.75 copies µl−1) compared to the healthy/mucositis group (173.04 copies µl−1, P<0.001). Higher concentrations of S. epidermidis correlated with increased probing depth, clinical attachment levels and bleeding on probing. Conclusions. The research strongly emphasizes the notable connection between S. epidermidis and peri-implantitis, indicating its potential impact on the development and progression of the condition. These findings underscore the significance of considering the quantity of S. epidermidis in clinical research aimed at effectively managing patients with peri-implant diseases.

16 July 2024 in Preprints.org
Verified
Preprint
Open access
PDF file
PMPanagiotis Manoudis
Panagiotis Manoudis
Ioannis ZuburtikudisIoannis Zuburtikudis
Ioannis Zuburtikudis
GKGeorgios Konstantopoulos
Georgios Konstantopoulos
HKHadil Abu Khalifeh
Hadil Abu Khalifeh
Christine KottaridiChristine Kottaridi
Christine Kottaridi
Ioannis KarapanagiotisIoannis Karapanagiotis
Ioannis Karapanagiotis
Wear phenomena on natural stone of the cultural heritage are induced from various sources. Consequently, the development of multifunctional protective materials which combine two or more useful properties is an effective strategy to address the synergistic effects of various wear mechanisms. A multifunctional coating, consisting of a silane-based precursor and zinc oxide (ZnO) nanoparticles (NPs), is produced and tested for the protection of limestone. The hybrid coating combines the following three properties: superhydrophobicity, including water-repellency, photocatalytic self-cleaning and biocidal activity. The relative concentration of the NPs (0.8% w/w), used for the suggested composite coating, is carefully selected according to wetting studies, colourimetric measurements and durability (tape peeling) tests. The non-wetting state is evidenced on the surface of the composite coating by the large contact angle of water drops (≈153°) and the small contact angle hysteresis (≈5°) which gives rise to the physical self-cleaning scenario (lotus effect). The photocatalytic chemical self-cleaning is shown with the removal of methylene blue, induced by the UV-A radiation. Moreover, it is shown that the suggested coating hinders the incubation of E. coli and S. aureus as the inhibition were 94.8 and 99.9 %, respectively. Finally, preliminary studies revealed the chemical stability of the suggested coating.