Spiro M. Konstantinov

Prof. Dr. Spiro M. Konstantinov


Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

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

Representative Publications

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20 May 2020 in Polymers
Verified
Journal Article
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DMDenitsa Momekova
Denitsa Momekova
EIErvin Ivanov
Ervin Ivanov
SKSpiro M. Konstantinov
Spiro M. Konstantinov
FUFilip Ublekov
Filip Ublekov
Petar Dimitrov PetrovPetar Dimitrov Petrov
Petar Dimitrov Petrov
In this contribution, we report the development of original nanocomposite cryogels for sustained topical delivery of hydrophobic natural active substances such as cannabidiol (CBD). The cryogels were fabricated by a method involving cryogenic treatment and photo-crosslinking of aqueous systems containing biodegradable 2-hydroxyethyl cellulose (HEC) and CBD-loaded polymeric micelles. The preparation of the water-soluble form of CBD was a key element for the successful drug loading in the one-pot reaction. The main physical, mechanical and biological characteristics of CBD-loaded and blank cryogels such as gel fraction yield, swelling degree, morphology, storage and loss moduli, and cytotoxicity were studied in detail. The advantage of nanocomposite over pure HEC cryogel carriers in terms of achieving a sustained release profile was also demonstrated.

31 December 2021 in Molecules
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Maya Margaritova ZaharievaMaya Margaritova Zaharieva
Maya Margaritova Zaharieva
Lyudmila DimitrovaLyudmila Dimitrova
Lyudmila Dimitrova
SPStanislav Philipov
Stanislav Philipov
INIvanka Nikolova
Ivanka Nikolova
NVNeli Milenova Vilhelmova-Ilieva
Neli Milenova Vilhelmova-Ilieva
Hristo NajdenskiHristo Najdenski
Hristo Najdenski
This study evaluated the in vitro antineoplastic and antiviral potential and in vivo toxicity of twelve extracts with different polarity obtained from the herbaceous perennial plant Geum urbanum L. (Rosaceae). In vitro cytotoxicity was determined by ISO 10993-5/2009 on bladder cancer, (T-24 and BC-3C), liver carcinoma (HEP-G2) and normal embryonic kidney (HEK-293) cell lines. The antineoplastic activity was elucidated through assays of cell clonogenicity, apoptosis induction, nuclear factor kappa B p65 (NFκB p65) activation and total glutathione levels. Neutral red uptake study was applied for antiviral activity. The most promising G. urbanum extract was analyzed by UHPLC–HRMS. The acute in vivo toxicity analysis was carried out following OEDC 423. The ethyl acetate extract of aerial parts (EtOAc-AP) exhibited the strongest antineoplastic activity on bladder cancer cell lines (IC50 = 21.33–25.28 µg/mL) by inducing apoptosis and inhibiting NFκB p65 and cell clonogenicity. EtOAc and n-butanol extracts showed moderate antiviral activity against human adenovirus type 5 and human simplex virus type I. Seventy four secondary metabolites (gallic and ellagic acid derivatives, phenolic acids, flavonoids, etc.) were identified in EtOAc-AP by UHPLC–HRMS. This extract induced no signs of acute toxicity in liver and kidney specimens of H-albino mice in doses up to 210 mg/kg. In conclusion, our study contributes substantially to the detailed pharmacological characterization of G. urbanum, thus helping the development of health-promoting phytopreparations.

23 April 2014 in Phytochemistry Reviews
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Journal Article
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YIY. Ilieva
Y. Ilieva
KKK. Kaloyanov
K. Kaloyanov
DYDeyan Yordanov Yosifov
Deyan Yordanov Yosifov
BRB. Robev
B. Robev
IZI. Zhelezova
I. Zhelezova
SKSpiro M. Konstantinov
Spiro M. Konstantinov

1 December 2022 in Pharmaceutics
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ATAntonios G. X. Trochopoulos
Antonios G. X. Trochopoulos
Yana IlievaYana Ilieva
Yana Ilieva
AKAlexander Dimitrov Kroumov
Alexander Dimitrov Kroumov
Lyudmila DimitrovaLyudmila Dimitrova
Lyudmila Dimitrova
IPIvanka Pencheva
Ivanka Pencheva
Maya Margaritova ZaharievaMaya Margaritova Zaharieva
Maya Margaritova Zaharieva
Cutaneous T-cell lymphoma (CTCL) is a rare form of cancer with local as well as systemic manifestations. Concomitant bacterial infections increase morbidity and mortality rates due to impaired skin barrier and immune deficiency. In the current study, we demonstrated that the in vitro anti-lymphoma potential of erufosine is diminished by TWIST1 expression and micellar curcumin substantially increases its antineoplastic activity. Pharmacokinetic analysis showed that the micellar curcumin (MCRM) used in our study was characterized by low zeta potential, slow release of curcumin, and fast cell membrane penetration. The combination ratio 1:4 [erufosine:MCRM] achieved strong synergism by inhibiting cell proliferation and clonogenicity. The combined antiproliferative effects were calculated using the symbolic mathematical software MAPLE 15. The synergistic combination strongly decreased the expression of TWIST1 and protein kinase B/Akt as proven by western blotting. Significant reductions in NF-κB activation, induction of apoptosis, and altered glutathione levels were demonstrated by corresponding assays. In addition, the synergistic combination enhanced the anti-staphylococcal activity and prevented biofilm formation, as shown by crystal violet staining. Taken together, the above results show that the development of nanotechnological treatment modalities for CTCL, based on rational drug combinations exhibiting parallel antineoplastic and antibacterial effects, may prove efficacious.

2 October 2024 in Fermentation
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SRSnezhana Rusinova-Videva
Snezhana Rusinova-Videva
Maya Margaritova ZaharievaMaya Margaritova Zaharieva
Maya Margaritova Zaharieva
DHDilyana Hristova
Dilyana Hristova
SNStefka Rumenova Nachkova
Stefka Rumenova Nachkova
MKMargarita Kambourova
Margarita Kambourova
SKSpiro M. Konstantinov
Spiro M. Konstantinov
Antarctic yeasts represent a poorly explored source of novel bioactive compounds with antineoplastic activity and a favorable toxicological profile. The present paper presents the newest data on the antiproliferative and antimicrobial potential of extracts obtained from the psychrophilic strain AL103 of the species Sporobolomyces roseus. The capacity of AL103 to grow under different cultivation conditions, including in a bioreactor system with optimal biomass quantities of approximately 6.0 g/L, was demonstrated. A comparative examination of the metabolic profiles (GC-MS-based) of yeast extracts revealed a wide variety of synthesized molecules responsible for the different levels of antineoplastic activity depending on the tissue origin of the malignant cell lines. Concentration response curves were generated by the MTT dye reduction test. The respective IC50 values were extrapolated and found between 35.3 and 163 µg/mL. The antibacterial potential of both extracts was evaluated with the broth microdilution test against four referent pathogenic bacterial strains. The estimated minimal inhibitory concentrations revealed a moderate antibacterial activity. According to the GC-MS results, both extracts are rich in long-chain fatty acids which are known for their antibacterial properties. In conclusion, the Antarctic strain AL103 possesses promising potential for further pharmacological investigations aiming to elucidate its application as a health-promoting food additive or/and as a source of biologically active compounds.

15 May 2013
Verified
Book Chapter
Open access
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MKMila Kaleva
Mila Kaleva
GAG. Amudov
G. Amudov
SKSpiro M. Konstantinov
Spiro M. Konstantinov
MLM. L.
M. L.