Blood Circulation in the Implantation Area of a Bioengineered Construct Based on Histological and Tomographic Examination in an Experimental Study

Extravascular macrocapsules represent a possible method for soft tissue defect replacement in the setting of a shortage of autologous tissues or when standard flaps cannot be used. The aim of the study was a morphofunctional evaluation of vascular condition and blood flow parameters at the site of bioengineered construct implantation, employing histological and tomographic examination methods.

Material and methods. The experiment was performed on 12 Wistar rats divided into 4 groups: Group 1 – empty 3D macrocapsule (n=3); Group 2 – 3D macrocapsule with bone marrow (n=3); Group 3 – 3D macrocapsule with bone marrow and nonwoven matrix (n=3); Group 4 – control group of sham-operated animals (n=3). One rat served as a donor of syngeneic bone marrow from the femoral bones. Implantation was performed onto the femoral neurovascular bundle. Assessment of the surgical site condition was carried out on days 3, 7, and 14. After necropsy on day 30, histological and morphometric evaluation of the vascular wall was performed using standard hematoxylin–eosin and Mallory staining. The thickness and morphology of the intima and media were assessed, along with the intima-to-media ratio. MRI examination with gadobutrol contrast enhancement was performed, followed by assessment of vascular patency and tissue perfusion parameters (Ktrans, Kep, Ve).

Results. Positive healing dynamics and the absence of signs of inflammation were observed in the implantation zone. In all groups, the vascular wall retained its typical three-layer structure, with no changes in the lumen, no evidence of media fibrosis, and no formation of pronounced intimal hyperplasia. Magnetic resonance imaging demonstrated preserved main blood flow and suggested enhanced perfusion of the tissue-engineered constructs placed within the 3D macrocapsule.

Conclusion. Implantation of all versions of extravascular macrocapsules onto the neurovascular bundle does not induce significant morphological changes or impair the systemic circulation of the femoral artery.

1. Bogdanov LA, Kutikhin AG. Optimization of hematoxylin and eosin staining of heart, blood vessels, liver, and spleen. Fundamental and Clinical Medicine. 2019; 4(4): 70-77. (in Russian). doi: 10.23946/2500-0764-2019-4-4-70-77

2. Bolbasov EN, Kudryavtseva VL, Stankevich KS, Antonova LV, Matveeva VG, Tverdokhlebov SI et al. Structure and certain properties of the nanofiber materials produced by electrospinning и solution blow spinning: comparative studies. Polymer materials and technologies. 2016; (4): 30–38. (In Russian). doi: 10.32864/polymmattech-2016-2-4-30-38

3. Dvornichenko MV, Marzol EA, Zinoviev EA, Mitryaykin NS, Khlusov IA. The state and vascularization of the bone marrow transplanted in the diffusion chamber to the rat neurovascular bundle. Bulletin of Siberian Medicine. 2024; 23(2): 37–45. (In Russian). doi: 10.20538/1682-0363-2024-2-37-45

4. Igamberdieva RSh, Karimdzhanova GA, Mirzaeva BM. Sostoyanie endoteliya sonnykh arteriy pri arterial'noy gipertonii [State of the carotid artery endothelium in arterial hypertension]. Molodoy uchenyy. 2017; (45): 77-84. (In Russian).

5. Marzol EA, Dvornichenko MV, Zinoviev EA, Zhernakov DE, Khlusov IA. Application of diffusion chambers for cell macroencapsulation: from concept to clinical trials (literature review). Siberian Journal of Clinical and Experimental Medicine. 2024; 39(4): 38-46. (In Russian). doi: 10.29001/2073-8552-2024-39-4-38-46

6. Albu M, Şeicaru DA, Pleşea RM, Mirea OC, Gherghiceanu F, Grigorean VT, et al. Remodeling of the aortic wall layers with ageing. Romanian Journal of Morphology and Embryology. 2022; 63(1): 71–82. doi:10.47162/RJME.63.1.07.

7. Asaad Amin M, Saleh S, Helmy M, Abbas M. A Histomorphometric study on the Effect of Consumption of Caffeinated Energy Drinks on the Aorta of the Adult Male Albino Rats. Egyptian Journal of Histology. 2022. doi:10.21608/ejh.2022.173318.1805

8. Ebert MLA, Schmidt VF, Öcal O, von Thaden A, Dietrich O, Popper B, et al. A minimally invasive animal model of atherosclerosis and neointimal hyperplasia for translational research. European Radiology Experimental. 2025; 9(1): 14. doi: 10.1186/s41747-025-00558-1

9. Field C, Welsh AH. Bootstrapping Clustered Data. Journal of the Royal Statistical Society Series B: Statistical Methodology. 2007;69(3):369–90. doi:10.1111/j.1467-9868.2007.00593.x

10. Fonseca DA, Antunes PE, Antunes MJ, Cotrim MD. Histomorphometric analysis of the human internal thoracic artery and relationship with cardiovascular risk factors. Pizzi C, editor. PLOS ONE. 2019; 14(1): e0211421. doi:10.1371/journal.pone.0211421

11. Fry DL. Certain histological and chemical responses of the vascular interface to acutely induced mechanical stress in the aorta of the dog. Circ Res. 1969;24(1):93-108. doi: 10.1161/01.res.24.1.93.

12. Geierlehner A, Horch RE, Ludolph I, Lang W, Rother U, Meyer A, Arkudas A. Intraoperative blood flow analysis of free flaps with arteriovenous loops for autologous microsurgical reconstruction. J Clin Med. 2023;12(23):7477. doi: 10.3390/jcm12237477

13. Geraci M. Linear Quantile Mixed Models: ThelqmmPackage for Laplace Quantile Regression. Journal of Statistical Software. 2014;57(13). doi:10.18637/jss.v057.i13.

14. Geraci M, Bottai M. Linear quantile mixed models. Statistics and Computing. 2014; 24(3): 461-479. doi:10.1007/s11222-013-9381-9.

15. Goreninskii S, Danilenko N, Filimonov V, Bolbasov E, Tverdokhlebov S, Evtina A, et al. Enhanced properties of poly(εcaprolactone)/polyvinylpyrrolidone electrospun scaffolds fabricated using 1,1,1,3,3,3-hexafluoro-2- propanol. Journal of Applied Polymer Science. 2021; 138(23): 50535. doi: 10.1002/app.50535

16. Hothorn T, Bretz F, Westfall P. Simultaneous inference in general parametric models. Biometrical Journal. 2008; 50(3): 346- 363. doi:10.1002/bimj.200810425

17. Li Y, Fraser D, Mereness J, Van Hove A, Basu S, Newman M, et al. Tissue Engineered Neurovascularization Strategies for Craniofacial Tissue Regeneration. ACS Appl Bio Mater. 2022; 5(1): 20-39. doi:10.1021/acsabm.1c00979

18. Metz R, Nobiling R, Harlacher M, Rosivall L, Taugner R. Cytoplasmic sequestration phenomena in smooth muscle cells of kidney resistance vessels and epithelioid cells of the juxtaglomerular apparatus. Virchows Arch a Pathol Anat Histopathol. 1988; 412(6): 583-9. doi:10.1007/BF00844294

19. Prabhu GS, Rao KG M, Concessao PL, Rai KS. Role of High-Fat Diet Alone on Lipids, Arterial Wall and Hippocampal Neural Cell Alterations in Animal Models and Their Implications for Humans. Biology (Basel). 2025; 14(8): 971. doi:10.3390/biology14080971

20. Royston P. Remark AS R94: A Remark on Algorithm AS 181: The W-test for Normality. Journal of the Royal Statistical Society. Series C (Applied Statistics). 1995; 44(4): 547-551. doi:10.2307/2986146

21. Weigand A, Beier JP, Arkudas A, Al-Abboodi M, Polykandriotis E, Horch RE, et al. The Arteriovenous (AV) Loop in a Small Animal Model to Study Angiogenesis and Vascularized Tissue Engineering. J. Vis. Exp. 2016; (117): e54676. doi:10.3791/54676

22. Westfall PH, Troendle JF. Multiple testing with minimal assumptions. Biometrical Journal. 2008; 50(5): 745-755. doi:10.1002/bimj.200710456

23. Wu YL, Szafron JM, Blum KM, Zbinden JC, Khosravi R, Best CA, et al. Electrospun TissueEngineered Arterial Graft Thickness Affects LongTerm Composition and Mechanics. Tissue Eng Part A. 2021; 27(9-10): 593-603. doi: 10.1089/ten.TEA.2020.0166