Kameliya Bratoeva

Prof. Dr. Kameliya Bratoeva

orcid

Research Focus & Metrics

Academic Career Length

17Years (2010-Present)

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

Representative Publications

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5 June 2024 in Gels
Verified
Journal Article
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Nadezhda IvanovaNadezhda Ivanova
Nadezhda Ivanova
NENeli Mitkova Ermenlieva
Neli Mitkova Ermenlieva
LSLora Simeonova
Lora Simeonova
NVNeli Milenova Vilhelmova-Ilieva
Neli Milenova Vilhelmova-Ilieva
KBKameliya Bratoeva
Kameliya Bratoeva
Velichka AndonovaVelichka Andonova
Velichka Andonova
A combination of Poloxamer 407 (P407) and hydroxypropyl methylcellulose (HPMC) hydrosols is proposed as an in situ thermo-gelling vehicle for the nasal drug delivery of chlorhexidine–silver nanoparticles conjugates (SN-CX). Optimization of the formulation was carried out by applying varying ratios of P407 and HPMC in the presence and absence of SN-CX so that gelation would occur in the temperature range of the nasal cavity (30–34 °C). Mechanisms for the observed gelation phenomena were suggested based on viscosimetry, texture analysis, and dynamic light scattering. Tests were carried out for sprayability, washout time, in vitro drug release, ex vivo permeation, and antimicrobial activity. When applied separately, HPMC was found to lower the P407 gelation temperature (Tg), whereas SN-CX increased it. However, in the presence of HPMC, SN-CX interfered with the P407 micellar organization in a principally contrasting way while leading to an even further decrease in Tg. SN-CX-loaded nasal formulations composed of P407 16% and HPMC 0.1% demonstrated a desired gelation at 31.9 °C, good sprayability (52.95% coverage of the anterior nasal cavity), mucoadhesion for 70 min under simulated nasal clearance, expedient release and permeation, and preserved anti-infective activity against seasonal Influenza virus and beta-coronavirus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus and other pathogens. Our findings suggest that the current development could be considered a potential formulation of a protective nasal spray against respiratory infections.

7 November 2017 in Cureus
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Journal Article
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KBKameliya Bratoeva
Kameliya Bratoeva
GSGeorge S. Stoyanov
George S. Stoyanov
AMAlbena Merdzhanova
Albena Merdzhanova
MRMariya Radanova
Mariya Radanova
International studies show an increased incidence of chronic kidney disease (CKD) in patients with metabolic syndrome (MS). It is assumed that the major components of MS - obesity, insulin resistance, dyslipidemia, and hypertension - are linked to renal damage through the systemic release of several pro-inflammatory mediators, such as uric acid (UA), C-reactive protein (CRP), and generalized oxidative stress. The aim of the present study was to investigate the extent of kidney impairment and manifestations of dysfunction in rats with fructose-induced MS. We used a model of high-fructose diet in male Wistar rats with 35% glucose-fructose corn syrup in drinking water over a duration of 16 weeks. The experimental animals were divided into two groups: control and high-fructose drinking (HFD). Serum samples were obtained from both groups for laboratory study, and the kidneys were extracted for observation via light microscopy examination. All HFD rats developed obesity, hyperglycemia, hypertriglyceridemia, increased levels of CRP and UA (when compared to the control group), and oxidative stress with high levels of malondialdehyde and low levels of reduced glutathione. The kidneys of the HFD group revealed a significant increase in kidney weight in the absence of evidence of renal dysfunction and electrolyte disturbances. Under light microscopy, the kidneys of the HFD group revealed amyloid deposits in Kimmelstiel-Wilson-like nodules and the walls of the large caliber blood vessels, early-stage atherosclerosis with visible ruptures and scarring, hydropic change (vacuolar degeneration) in the epithelial cells covering the proximal tubules, and increased eosinophilia in the distant tubules when compared to the control group. Under the conditions of a fructose-induced metabolic syndrome, high serum UA and CRP correlate to the development of early renal disorders without a clinical manifestation of renal dysfunction. These phenomena are of particular importance for assessing the risk of developing future CKD.

Verified
Journal Article
Open access
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KBKameliya Bratoeva
Kameliya Bratoeva
Maria RadanovaMaria Radanova
Maria Radanova
Albena MerdzhanovaAlbena Merdzhanova
Albena Merdzhanova
IDIvan Donev
Ivan Donev
Introduction. It has been shown that S-adenosylmethionine (S-AMe) stimulates glutathione synthesis and increases cell resistance to the cytotoxic action of free radicals and pro-inflammatory cytokines. The aim of this study was to determine the effect of S-adenosylmethionine on the oxidative stress in adipose tissue in a model of fructose-induced obesity. Methods. The study was performed on male Wistar rats divided into 3 groups: control, fructose fed (HFD) (35%, 16 weeks), and HFD + S-AMe (20 mg/kg). We examined the changes in the ratio of retroperitoneal adipose tissue weight / body weight; levels of reduced glutathione (GSH) and malondialdehyde (MDA) in the retroperitoneal adipose tissue, and serum levels of GSH and TNF-α. Results. Significant increases in the retroperitoneal adipose tissue, MDA, and serum TNF-α were identified, as well as decreased tissue and serum levels of GSH in rats fed with a high-fructose diet as compared with the control group. In the group fed with HFD and S-AMe, we found significant reduction in the retroperitoneal adipose tissue and decreased levels of MDA and serum TNF-α, as well as increased tissue and serum levels of GSH as compared with the group only on HFD. In conclusion, our results show that fructose-induced obesity causes oxidative stress in hypertrophic visceral adipose tissue. The administration of S-AMe improves the antioxidative protection of adipocytes, and reduces oxidative damage and excessive accumulation of lipids and inflammation.

17 August 2020 in Journal of IMAB – Annual Proceeding (Scientific Papers)
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Journal Article
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Veselina PanayotovaVeselina Panayotova
Veselina Panayotova
Albena MerdzhanovaAlbena Merdzhanova
Albena Merdzhanova
Diana Atanasova DobrevaDiana Atanasova Dobreva
Diana Atanasova Dobreva
KBKameliya Bratoeva
Kameliya Bratoeva
LMLubomir Makedonski
Lubomir Makedonski

23 April 2024 in Preprints.org
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Preprint
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NINadezhda Ivanova
Nadezhda Ivanova
NENeli Mitkova Ermenlieva
Neli Mitkova Ermenlieva
LSLora Simeonova
Lora Simeonova
NVNeli Milenova Vilhelmova-Ilieva
Neli Milenova Vilhelmova-Ilieva
KBKameliya Bratoeva
Kameliya Bratoeva
Velichka AndonovaVelichka Andonova
Velichka Andonova
A combination of Poloxamer 407 (P407) and hydroxypropyl methylcellulose (HPMC) hydrosols is proposed as an in situ thermo-gelling vehicle for the nasal drug delivery of chlorhexidine-silver nanoparticles conjugates (SN-CX). Varying ratios of P407 and HPMC were applied in the presence and absence of SN-CX in order to optimize the gelation temperature (Tg) to values close to the physiological nasal such (30–34°C). Mechanisms for the observed gelation phenomena were suggested based on viscosimetry, texture analysis, and dynamic light scattering. Tests were carried out for sprayability, washout time, in vitro drug release, ex vivo permeation, and antimicrobial activity. When applied separately, HPMC was found to lower the P407 gelation temperature, whereas SN-CX increased it. However, in the presence of HPMC, SN-CX interfered with the P407 micellar organization in a principally contrasting way, while leading to an even further decrease in Tg. SN-CX-loaded nasal formulation composed of P407 16% and HPMC 0.1% demonstrated a desired gelation at 31.9 °C, good sprayability (52.95% coverage of the anterior nasal cavity), mucoadhesion for 70 min under simulated nasal clearance, expedient release and permeation, and preserved anti-infective activity against seasonal Influenza virus and beta-coronavirus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus and other pathogens. Our findings suggest that the current development could be considered a potential formulation of a protective nasal spray against respiratory infections.

29 July 2025 in Veterinarni Medicina
Verified
Journal Article
Open access
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DCDariya Chivchibashi-Pavlova
Dariya Chivchibashi-Pavlova
KBKameliya Bratoeva
Kameliya Bratoeva
Autism spectrum disorder (ASD) is a group of human neurodevelopmental disorders with significant global prevalence. Deficits in social communication and interaction and repetitive, stereotyped patterns of behaviour characterise ASD. The aetiol...