Alexandr Bubnov

Mr. Alexandr Bubnov


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

View All Publications
5 August 2023 in Nanomaterials
Verified
Journal Article
Open access
PDF file
ABAlexandr Bubnov
Alexandr Bubnov
VBVladimir S. Belov
Vladimir S. Belov
YKYulia V. Kargina
Yulia V. Kargina
GTGleb Tikhonowski
Gleb Tikhonowski
APAnton Popov
Anton Popov
Victor TimoshenkoVictor Timoshenko
Victor Timoshenko
The combination of photothermal and magnetic functionalities in one biocompatible nanoformulation forms an attractive basis for developing multifunctional agents for biomedical theranostics. Here, we report the fabrication of silicon–iron (Si-Fe) composite nanoparticles (NPs) for theranostic applications by using a method of femtosecond laser ablation in acetone from a mixed target combining silicon and iron. The NPs were then transferred to water for subsequent biological use. From structural analyses, it was shown that the formed Si-Fe NPs have a spherical shape and sizes ranging from 5 to 150 nm, with the presence of two characteristic maxima around 20 nm and 90 nm in the size distribution. They are mostly composed of silicon with the presence of a significant iron silicide content and iron oxide inclusions. Our studies also show that the NPs exhibit magnetic properties due to the presence of iron ions in their composition, which makes the formation of contrast in magnetic resonance imaging (MRI) possible, as it is verified by magnetic resonance relaxometry at the proton resonance frequency. In addition, the Si-Fe NPs are characterized by strong optical absorption in the window of relative transparency of bio-tissue (650–950 nm). Benefiting from such absorption, the Si-Fe NPs provide strong photoheating in their aqueous suspensions under continuous wave laser excitation at 808 nm. The NP-induced photoheating is described by a photothermal conversion efficiency of 33–42%, which is approximately 3.0–3.3 times larger than that for pure laser-synthesized Si NPs, and it is explained by the presence of iron silicide in the NP composition. Combining the strong photothermal effect and MRI functionality, the synthesized Si-Fe NPs promise a major advancement of modalities for cancer theranostics, including MRI-guided photothermal therapy and surgery.

15 October 2021 in Digital Diagnostics
Verified
Journal Article
Open access
PDF file
PRPavel O. Rumiantsev
Pavel O. Rumiantsev
ABAlexandr Bubnov
Alexandr Bubnov
MDMikhail V. Degtyarev
Mikhail V. Degtyarev
KSKonstantin Y. Slushchuk
Konstantin Y. Slushchuk
SZSvetlana M. Zakharova
Svetlana M. Zakharova
ДВДегтярев Михаил Владимирович
Дегтярев Михаил Владимирович
The pathologies of parathyroid glands are widespread among endocrine system diseases, excluding diabetes and thyroid pathology. There are only two methods that are used to treat hyperparathyroidisms, such as surgery and conservative therapy. However, transracial thermal destruction methods (ablation) have recently appeared in clinical practice. The methods have good precision and connect with physical phenomena, such as interaction laser, radiofrequency, microwave, and HIFU irradiation with bio substance. The review is dedicated to critically analyze the modern methods for local thermal destruction of the hyper-functioning parathyroid glands. The review includes data from randomized clinical trials from 2012 to 2021. The studies were from Google Scholar and Pubmed with a total number of 1,938 patients (laser ablation ― 216 patients, radiofrequency ablation ― 225, microwave ablation ― 1467, high-density ultrasound ablation ― 30 patients). Recommendations methods of thermal destruction application were obtained during the review. Furthermore, we have designed some algorithms for hyperparathyroidism treatment. Moreover, thermal destruction methods were observed. There are four modern methods of thermal destruction which have been analyzed like alternatives to surgery. Each of them has advantages and disadvantages, its profile of safety and effectiveness. After processing information from a proven database, the most popular among specialists is methods of microwave ablation. However, laser ablation is more effective than other ways.

7 September 2022 in Endocrine Surgery
Verified
Journal Article
Open access
PDF file
ABAlexandr Bubnov
Alexandr Bubnov
KSK. Yu. Slashchuk
K. Yu. Slashchuk
ESE. A. Shirshin
E. A. Shirshin
Victor TimoshenkoVictor Timoshenko
Victor Timoshenko
Nowadays, diabetes and diseases of thyroid gland take place on the first two stage in the rank of all endocrine diseases. There are 3 directions to treat thyroid glands pathologies such as: using special pills which substitute natural thyroid hormones, surgery and radioiodine therapy. It has proven that surgery of thyroid gland is the most effective method among considering upper. at The same time, it is associated with the greatest risks of complications. The most common injuries are damage to the recurrent laryngeal nerve and unintentional traumatization or removal of a healthy parathyroid gland. Parathyroid gland is a critical organ during thyroid surgery. It means that all negative reaction nearby the structure can lead to development different complications: hypoparathyroidism (transient or chronic) and hypocalcemia. In this article is considered actual methods of intraoperative optical visualization of parathyroid glans. The fundamental foundations of such methods, their advantages and disadvantages are also analyzed. It is shown that fluorescent methods in the red and near infrared regions of the spectrum using exogenous dyes have essential importance for endocrine surgery, as they allow to improve identification and reduce the risk of postoperative complications.

22 July 2021 in Research Square
Verified
Preprint
Open access
PDF file
ABAlexandr Bubnov
Alexandr Bubnov
ATAlexey A Trukhin
Alexey A Trukhin
PRPavel O Rumyantsev
Pavel O Rumyantsev
MDMikhail V Degtyarev
Mikhail V Degtyarev
YSYaroslaw I Sirota
Yaroslaw I Sirota
NMNatalya G Mokrysheva
Natalya G Mokrysheva
Purposes: Current research design is dedicated to 131-I SUV evaluation on post therapeutic scintigrams and setting up predictive model for radioiodine therapy repeated course prescription in differentiated thyroid cancer (DTC). Methods: Study includes 148 patients (f-105, m-43) with DTC treated with 131-iodine. Administered treatment activities of 131I calculated according to clinical features and tumor recurrence risk group. Patients were divided into three groups using ATA 2018 recommendations. Absolute risk groups: low risk (L), medium risk (M), high risk (H). Administered 131-I activity [MBq]: = 3223±729, = 3696±456, = 4589±1078; Tg [ng/ml]: = 7,4±1.7 ng/ml, = 14,8 ±5,9, = 68,3 ±18,5; TgAb [IU/ml]: = 124,3 ± 81.7, = 29,2 ±15,9, = 85,7 ±28,9. All null hypothesis were checked using paired Mann-Whitney U-test. Calibration of system SPECT/CT and evaluation SUVs completed according to protocols designed using Jaszczak phantom Deluxe. Model development based on logistic regression with ROC-analysis, regularization and cross-validation. Results: Reference intervals of SUVpeak and SUVmax calculated for all groups of risk. SUVpeak: low risk >155, medium risk 105-155, high risk 0-105 pL-M=0.069 pL-H=0.0037 pM-H=0.7514; SUVmax: low risk >38, medium risk 29-38, high risk 0-29 pL-M=0.052 pL-H=0.0033 pM-H=0.949. Logit model based on SUVpeak without regularization has: AUC = 0.67 (95%CI 0.33-1.00); Accuracy = 0.82; SE = 0.89; SP = 0.4; PPV = 0.41; NPV = 0.89, cross-validated AUC =0.67 (0.4-0.88), regression coefficients: B0=0.037, B1=0.001. Regularization (SUVpeak<100) lead to AUC = 0.75, (95%CI 0.44-1.00); accuracy = 0.89; SE =0.98; SP = 0.4; PPV = 0.76; NPV = 0.87, cross-validated AUC = 0.513 (0.36-0.71) regression coefficients: B0=0.473, B1=0.003.Conclusion: Study shows that SUV has wide range of values and can be matched with existed model of risk assessment of DTC. Algorithm of image segmentation and evaluation of SUVpeak and SUVmax for SPECT/CT systems was developed. According to the ROC analysis, developed predictive model shows an acceptable performance for further clinical investigation and advancement focused on refining model parameters and introducing additional predictors