Tonya Andreeva

Dr. Tonya Andreeva

University of Reutlingen, Reutlingen, Germany
+1
orcid

Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

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

Representative Publications

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23 July 2021 in ACS Biomaterials Science & Engineering
Verified
Journal Article
Closed access
MSmina shahriari-khalaji
mina shahriari-khalaji
GHGaoquan Hu
Gaoquan Hu
LCLin Chen
Lin Chen
ZCZhangjun Cao
Zhangjun Cao
TATonya Andreeva
Tonya Andreeva
FHFeng Hong
Feng Hong

20 March 2019 in Oxidative Medicine and Cellular Longevity
Verified
Journal Article
Open access
NKNatalia Krasteva
Natalia Krasteva
Milena Keremidarska-MarkovaMilena Keremidarska-Markova
Milena Keremidarska-Markova
Kamelia Hristova-PanushevaKamelia Hristova-Panusheva
Kamelia Hristova-Panusheva
TATonya Andreeva
Tonya Andreeva
Giorgio SperanzaGiorgio Speranza
Giorgio Speranza
Milena GeorgievaMilena Georgieva
Milena Georgieva
Nanotechnology-based drug delivery systems for cancer therapy are the topic of interest for many researchers and scientists. Graphene oxide (GO) and its derivates are among the most extensively studied delivery systems of this type. The increased surface area, elevated loading capacity, and aptitude for surface functionalization together with the ability to induce reactive oxygen species make GO a promising tool for the development of novel anticancer therapies. Moreover, GO nanoparticles not only function as effective drug carriers but also have the potential to exert their own inhibitory effects on tumour cells. Recent results show that the functionalization of GO with different functional groups, namely, with amine groups, leads to increased reactivity of the nanoparticles. The last steers different hypotheses for the mechanisms through which this functionalization of GO could potentially lead to improved anticancer capacity. In this research, we have evaluated the potential of amine-functionalized graphene oxide nanoparticles (GO-NH2) as new molecules for colorectal cancer therapy. For the purpose, we have assessed the impact of aminated graphene oxide (GO) sheets on the viability of colon cancer cells, their potential to generate ROS, and their potential to influence cellular proliferation and survival. In order to elucidate their mechanism of action on the cellular systems, we have probed their genotoxic and cytostatic properties and compared them to pristine GO. Our results revealed that both GO samples (pristine and aminated) were composed of few-layer sheets with different particle sizes, zeta potential, and surface characteristics. Furthermore, we have detected increased cyto- and genotoxicity of the aminated GO nanoparticles following 24-hour exposure on Colon 26 cells. The last leads us to conclude that exposure of cancer cells to GO, namely, aminated GO, can significantly contribute to cancer cell killing by enhancing the cytotoxicity effect exerted through the induction of ROS, subsequent DNA damage, and apoptosis.

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VSVelichka Strijkova
Velichka Strijkova
STSvetla Todinova
Svetla Todinova
TATonya Andreeva
Tonya Andreeva
DBDesislava Bogdanova
Desislava Bogdanova
ALAriana Langari
Ariana Langari
STStefka Taneva
Stefka Taneva
Human red blood cells (RBCs) are unique cells with the remarkable ability to deform, which is crucial for their oxygen transport function, and which can be significantly altered under pathophysiological conditions. Here we performed ultrastructural analysis of RBCs as a peripheral cell model, looking for specific signatures of the neurodegenerative pathologies (NDDs)—Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS) and Alzheimer’s disease (AD), utilizing atomic force (AFM) and conventional optical (OM) microscopy. We found significant differences in the morphology and stiffness of RBCs isolated from patients with the selected NDDs and those from healthy individuals. Neurodegenerative pathologies’ RBCs are characterized by a reduced abundance of biconcave discoid shape, lower surface roughness and a higher Young’s modulus, compared to healthy cells. Although reduced, the biconcave is still the predominant shape in ALS and AD cells, while the morphology of PD is dominated by crenate cells. The features of RBCs underwent a marked aging-induced transformation, which followed different aging pathways for NDDs and normal healthy states. It was found that the diameter, height and volume of the different cell shape types have different values for NDDs and healthy cells. Common and specific morphological signatures of the NDDs were identified.

1 September 2013 in Journal of Photochemistry and Photobiology B: Biology
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Journal Article
Closed access
Sashka KrumovaSashka Krumova
Sashka Krumova
Miroslava ZhiponovaMiroslava Zhiponova
Miroslava Zhiponova
Kolyo DankovKolyo Dankov
Kolyo Dankov
VVVioleta Velikova
Violeta Velikova
Konstantin BalashevKonstantin Balashev
Konstantin Balashev
STS. Taneva
S. Taneva

1 November 2013 in Surface and Coatings Technology
Verified
Journal Article
Closed access
RBRayna Bryaskova
Rayna Bryaskova
NGNelly Georgieva
Nelly Georgieva
TATonya Andreeva
Tonya Andreeva
Rumiana TzonevaRumiana Tzoneva
Rumiana Tzoneva