Petya B. Tsekova

Dr. Petya B. Tsekova


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

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

Representative Publications

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18 May 2021 in Polymers
Verified
Journal Article
Open access
PDF file
Maria SpasovaMaria Spasova
Maria Spasova
NMNevena Manolova
Nevena Manolova
IRIliya Rashkov
Iliya Rashkov
PTPetya B. Tsekova
Petya B. Tsekova
RTReneta Toshkova
Reneta Toshkova
NMNadya Markova
Nadya Markova
Novel eco-friendly fibrous materials with complex activities from cellulose acetate and cellulose acetate/polyethylene glycol (CA,PEG) containing 5-chloro-8-hydroxyquinoline as a model drug were obtained by electrospinning. Several methods, including scanning electron microscopy, X-ray diffraction analysis, ultraviolet-visible spectroscopy, water contact angle measurements, and mechanical tests, were utilized to characterize the obtained materials. The incorporation of PEG into the fibers facilitated the drug release. The amounts of the released drug from CA/5-Cl8Q and CA,PEG/5-Cl8Q were 78 ± 3.38% and 86 ± 3.02%, respectively (for 175 min). The antibacterial and antifungal activities of the obtained materials were studied. The measured zones of inhibition of CA/5-Cl8Q and CA,PEG/5-Cl8Q mats were 4.0 ± 0.18 and 4.5 ± 0.2 cm against S. aureus and around 4.0 ± 0.15 and 4.1 ± 0.22 cm against E. coli, respectively. The complete inhibition of the C. albicans growth was detected. The cytotoxicity of the obtained mats was tested toward HeLa cancer cells, SH-4 melanoma skin cells, and mouse BALB/c 3T3 fibroblasts as well. The CA/5-Cl8Q and CA,PEG/5-Cl8Q materials exhibited anticancer activity and low normal cell toxicity. Thus, the obtained fibrous materials can be suitable candidates for wound dressing applications and for application in local cancer treatment.

28 September 2024 in Polymers
Verified
Journal Article
Open access
PDF file
PTPetya B. Tsekova
Petya B. Tsekova
NNNasko Nachev
Nasko Nachev
IVIliyana Valcheva
Iliyana Valcheva
DDDonka Draganova
Donka Draganova
MNMladen Naydenov
Mladen Naydenov
Olya StoilovaOlya Stoilova
Olya Stoilova
One of the latest trends in sustainable agriculture is the use of beneficial microorganisms to stimulate plant growth and biologically control phytopathogens. Bacillus subtilis, a Gram-positive soil bacterium, is recognized for its valuable properties in various biotechnological and agricultural applications. This study presents, for the first time, the successful encapsulation of B. subtilis within electrospun poly(3-hydroxybutyrate) (PHB) fibers, which are dip-coated with cellulose derivatives. In that way, the obtained fibrous biohybrid materials actively ensure the viability of the encapsulated biocontrol agent during storage and promote its normal growth when exposed to moisture. Aqueous solutions of the cellulose derivatives—sodium carboxymethyl cellulose and 2-hydroxyethyl cellulose, were used to dip-coat the electrospun PHB fibers. The study examined the effects of the type and molecular weight of these cellulose derivatives on film formation, mechanical properties, bacterial encapsulation, and growth. Scanning electron microscopy (SEM) was utilized to observe the morphology of the biohybrid materials and the encapsulated B. subtilis. Additionally, ATR-FTIR spectroscopy confirmed the surface chemical composition of the biohybrid materials and verified the successful coating of PHB fibers. Mechanical testing revealed that the coating enhanced the mechanical properties of the fibrous materials and depends on the molecular weight of the used cellulose derivatives. Viability tests demonstrated that the encapsulated B. subtilis exhibited normal growth from the prepared materials. These findings suggest that the developed fibrous biohybrid materials hold significant promise as biocontrol formulations for plant protection and growth promotion in sustainable agriculture.

22 November 2022 in Polymers
Verified
Journal Article
Open access
PDF file
PTPetya B. Tsekova
Petya B. Tsekova
Olya StoilovaOlya Stoilova
Olya Stoilova
The creation of eco-friendly clay-based composites for pollutant removal by adsorption still remains a challenge. This problem might be successfully solved by the development of electrospun polymer–clay composites. For the first time in this study, a one-step fabrication of cellulose acetate (CA) fibers filled with commercially available nanoclays (NCs) was described. The optimal ratio at which CA/NCs dispersions remained stable was accomplished by varying the nanoclay concentration with respect to CA. Furthermore, the selected solvent system and the electrospinning conditions allowed for the successful fabrication of electrospun CA/NC composites. It was found that the composites’ surface morphology was not affected by the incorporated nanoclays and was the same as that of the electrospun CA fibers. The performed analyses clearly showed that CA and nanoclays did not react during the electrospinning process. It was found that the distribution of nanoclay layers probably was a mixture of intercalated and exfoliated structures. Notably, the type of the nanoclay strongly influenced the adsorption ability of CA/NC composites toward Cr(VI) ions and MB dye. These results suggested that the fabricated CA/NC composites are suitable for pollutant removal due to their specific structure.

25 October 2021 in Polymers
Verified
Journal Article
Open access
PDF file
NNNasko Nachev
Nasko Nachev
Maria SpasovaMaria Spasova
Maria Spasova
PTPetya B. Tsekova
Petya B. Tsekova
NMNevena Manolova
Nevena Manolova
IRIliya Rashkov
Iliya Rashkov
MNMladen Naydenov
Mladen Naydenov
Nowadays, diseases in plants are a worldwide problem. Fungi represent the largest number of plant pathogens and are responsible for a range of serious plant diseases. Esca is a grapevine disease caused mainly by fungal pathogens Phaeomoniella chlamydospora (P. chlamydospora) and Phaeoacremonium aleophilum (P. aleophilum). The currently proposed methods to fight esca are not curative. In this study, polymer composites based on biodegradable polymer containing chemical fungicides with antifungal activity were successfully prepared by electrospinning. The obtained materials were hydrophobic with good mechanical properties. In vitro studies demonstrated that the fungicide release was higher from PLLA/K5N8Q fibrous mats (ca. 72% for 50 h) compared to the released drug amount from PLLA/5-Cl8Q materials (ca. 52% for 50 h), which is due to the better water-solubility of the salt. The antifungal activity of the fibrous materials against P. chlamydospora and P. aleophilum was studied as well. The incorporation of the fungicide in the biodegradable fibers resulted in the inhibition of fungal growth. The obtained materials are perspective candidates for the protection of vines from the penetration and growth of fungal pathogens.

25 June 2025 in Agronomy
Verified
Journal Article
Open access
PDF file
PTPetya B. Tsekova
Petya B. Tsekova
MPMariana Krasimirova Petkova
Mariana Krasimirova Petkova
Maria SpasovaMaria Spasova
Maria Spasova
Olya StoilovaOlya Stoilova
Olya Stoilova
This study reports, for the first time, the successful application of chitosan oligosaccharide (COS) and 2-hydroxyethyl cellulose (HEC) coatings on electrospun poly(3-hydroxybutyrate) (PHB) materials for the immobilization of non-conventional yeast strains with fungal biocontrol potential. The coatings enhanced the surface wettability of PHB fibers, facilitating efficient yeast adhesion and viability maintenance. Among the tested strains, Pichia acaciae YD6 was newly isolated and characterized, while Pichia fermentans YP6 and Zygosaccharomyces bailii YE1 had previously been identified as endophytic colonizers. All three strains demonstrated high adaptability, efficient immobilization, and antagonistic activity, confirming their potential for biocontrol applications. COS-coated PHB fibers promoted greater colony expansion than those coated with HEC. Antifungal assays of the yeast-containing biocarriers showed significant inhibition of F. graminearum growth. These findings underscore the potential of PHB-based fibrous materials as sustainable, bioactive carriers for yeast immobilization, with desirable biological properties. This approach offers a promising and eco-friendly strategy for pest control and bioactive agent delivery in agricultural applications.

18 February 2026 in Polymers
Verified
Journal Article
Open access
PDF file
NNNasko Nachev
Nasko Nachev
PTPetya B. Tsekova
Petya B. Tsekova
DDDonka Draganova
Donka Draganova
IVIliyana Valcheva
Iliyana Valcheva
Maria SpasovaMaria Spasova
Maria Spasova
Olya StoilovaOlya Stoilova
Olya Stoilova
The increasing demand for sustainable agriculture necessitates the development of eco-friendly alternatives to chemical pesticides. This study reports the design and characterization of biodegradable fibrous mats for the delivery of Bacillus subtilis, a plant-beneficial biocontrol agent, using cellulose acetate (CA) scaffolds functionalized with chitooligosaccharides (COS). Electrospun CA fibers were coated by electrospraying with COS or COS/B. subtilis suspensions in a single-step process to produce open, porous biohybrid scaffolds. Scanning electron microscopy confirmed uniform fiber formation and successful deposition of COS and bacterial layers, while ATR-FTIR spectroscopy verified the chemical composition of the fibrous mats. Water contact angle measurements indicated a shift from hydrophobic to highly hydrophilic surfaces, enhancing microbial adhesion and moisture-mediated activation. Mechanical testing demonstrated that thin COS coatings slightly improved tensile strength without compromising flexibility. Viability assays confirmed that encapsulated B. subtilis remained viable and capable of sporulation, and dual-culture assays demonstrated effective inhibition of Alternaria solani, Fusarium avenaceum, and Rhizoctonia solani. These results indicate that the electrospun/electrosprayed CA/COS platform provides a protective, sustainable, and effective delivery system for biocontrol agents. This approach offers a promising strategy for reducing reliance on synthetic pesticides while maintaining crop protection efficacy.