Plamen Zagorchev

Prof. Plamen Zagorchev

Medical University Pleven, Pleven, Bulgaria
orcid

Research Focus & Metrics

Academic Career Length

29Years (1998-Present)

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

Representative Publications

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1 December 2018 in Folia Medica
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MMMaria Zaharieva Mutafchieva
Maria Zaharieva Mutafchieva
MDMilena N. Draganova-Filipova
Milena N. Draganova-Filipova
PZPlamen Zagorchev
Plamen Zagorchev
GTGeorge T. Tomov
George T. Tomov
Lichen planus is a chronic mucocutaneous inflammatory disease aff ecting 1-2% of the general population with maximum prevalence of the disease in women above the age of 40. Its aetiology remains unclear and the pathogenesis is still the object of much speculation. It is considered to be an autoimmune disorder mediated mainly by the T-lymphocytes. The present paper presents the most well-known external agents (viruses in particular), internal agents like stress, and the heat shock protein thought to be trigger factors and describes the action of diff erent cells and proteins associated with the development of that disease. Diagnosis is based on clinical and histopathologic evidence; direct and indirect immunofluorescence techniques can also be of use. Despite the wide variety of therapeutic modalities, treatment outcomes are often insufficient. Currently, topical corticosteroids are widely accepted as a standard therapy, but also retinoids, calcineurin inhibitors and other immunosuppressants can be administered. Because of the aspect relevant to these drugs, priority is given to alternative harmless methods such as LLLT and PDLT. There is an ongoing controversy in the literature about the possible premalignant character of oral lichen planus, however, periodic followup is recommended.

23 November 2012 in Applied Biochemistry and Biotechnology
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SDStela Dimitrova
Stela Dimitrova
KPKostantsa Pavlova
Kostantsa Pavlova
LLLudmil Lukanov
Ludmil Lukanov
EKElena Korotkova
Elena Korotkova
EPEkaterina Petrova
Ekaterina Petrova
MKMargarita Kuncheva
Margarita Kuncheva

4 August 2023 in Biomedicines
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Radka Petkova BoyuklievaRadka Petkova Boyuklieva
Radka Petkova Boyuklieva
PZPlamen Zagorchev
Plamen Zagorchev
Bissera PilichevaBissera Pilicheva
Bissera Pilicheva
Direct nose-to-brain drug delivery offers the opportunity to treat central nervous system disorders more effectively due to the possibility of drug molecules reaching the brain without passing through the blood–brain barrier. Such a delivery route allows the desired anatomic site to be reached while ensuring drug effectiveness, minimizing side effects, and limiting drug losses and degradation. However, the absorption of intranasally administered entities is a complex process that considerably depends on the interplay between the characteristics of the drug delivery systems and the nasal mucosa. Various preclinical models (in silico, in vitro, ex vivo, and in vivo) are used to study the transport of drugs after intranasal administration. The present review article attempts to summarize the different computational and experimental models used so far to investigate the direct delivery of therapeutic agents or colloidal carriers from the nasal cavity to the brain tissue. Moreover, it provides a critical evaluation of the data available from different studies and identifies the advantages and disadvantages of each model.

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Milena GeorgievaMilena Georgieva
Milena Georgieva
BVBela Vasileva
Bela Vasileva
Giorgio SperanzaGiorgio Speranza
Giorgio Speranza
Dayong WangDayong Wang
Dayong Wang
KSKalin Stoyanov
Kalin Stoyanov
NKNatalia Krasteva
Natalia Krasteva
Clinically, there is an urgent need to identify new therapeutic strategies for selectively treating cancer cells. One of the directions in this research is the development of biocompatible therapeutics that selectively target cancer cells. Here, we show that novel aminated graphene oxide (haGO-NH2) nanoparticles demonstrate increased toxicity towards human hepatocellular cancer cells compared to pristine graphene oxide(GO). The applied novel strategy for amination leads to a decrease in the size of haGO-NH2 and their zeta potential, thus, assuring easier penetration through the cell membrane. After characterization of the biological activities of pristine and aminated GO, we have demonstrated strong cytotoxicity of haGO-NH2 toward hepatic cancer cells—HepG2 cell line, in a dose-dependent manner. We have presented evidence that the cytotoxic effects of haGO-NH2 on hepatic cancer cells were due to cell membrane damage, mitochondrial dysfunction and increased reactive oxygen species (ROS) production. Intrinsically, our current study provides new rationale for exploiting aminated graphene oxide as an anticancer therapeutic.

31 January 2023 in Pharmaceutics
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Nikolay ZaharievNikolay Zahariev
Nikolay Zahariev
MDMilena Draganova
Milena Draganova
PZPlamen Zagorchev
Plamen Zagorchev
Bissera PilichevaBissera Pilicheva
Bissera Pilicheva
The aim of this study was to develop casein-based nanoscale carriers as a potential delivery system for daunorubicin, as a pH-responsive targeting tool for acute lymphocytic leukemia. A coacervation technique followed by nano spray-drying was used for the preparation of drug-loaded casein nanoparticles. Four batches of drug-loaded formulations were developed at varied drug–polymer ratios using a simple coacervation technique followed by spray-drying. They were further characterized using scanning electron microscopy, dynamic light scattering, FTIR spectroscopy, XRD diffractometry, and differential scanning calorimetry. Drug release was investigated in different media (pH 5 and 7.4). The cytotoxicity of the daunorubicin-loaded nanoparticles was compared to that of the pure drug. The influence of the polymer-to-drug ratio on the nanoparticles’ properties such as their particle size, surface morphology, production yield, drug loading, entrapment efficiency, and drug release behavior was studied. Furthermore, the cytotoxicity of the drug-loaded nanoparticles was investigated confirming their potential as carriers for daunorubicin delivery.

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TGTsenka Grancharova
Tsenka Grancharova
PZPlamen Zagorchev
Plamen Zagorchev
Bissera PilichevaBissera Pilicheva
Bissera Pilicheva
Photothermal therapy (PTT) can overcome cancer treatment resistance by enhancing the cell membrane permeability, facilitating drug accumulation, and promoting drug release within the tumor tissue. Iron oxide nanoparticles (IONPs) have emerged as effective agents for PTT due to their unique properties and biocompatibility. Approved for the treatment of anemia, as MRI contrast agents, and as magnetic hyperthermia mediators, IONPs also offer excellent light-to-heat conversion and can be manipulated using external magnetic fields for targeted accumulation in specific tissue. Optimizing parameters such as the laser wavelength, power density, shape, size, iron oxidation state, functionalization, and concentration is crucial for IONPs’ effectiveness. In addition to PTT, IONPs enhance other cancer treatment modalities. They improve tumor oxygenation, enhancing the efficacy of radiotherapy and photodynamic therapy. IONPs can also trigger ferroptosis, a programmed cell death pathway mediated by iron-dependent lipid peroxidation. Their magneto-mechanical effect allows them to exert a mechanical force on cancer cells to destroy tumors, minimizing the damage to healthy tissue. This review outlines strategies for the management of the photothermal performance and PTT efficiency with iron oxide nanoparticles, as well as synergies with other cancer therapies.