Original Scientific Article
Radiological and histological assessment of the regeneration of experimental fractures of critical length, treated with hydroxyapatite alone and in combination with autologous PRP-gel
Georgi Marinov Marinov * ,
Nadya Zlatozareva Zlateva-Panayotova ,
Vesela Ivanova Todorova

Mac Vet Rev 2026; 49 (2): i - xiv

10.2478/macvetrev-2026-0021

Received: 07 October 2025

Received in revised form: 28 January 2026

Accepted: 09 April 2026

Available Online First: 31 July 2026

Published on: 15 October 2026

Correspondence: Georgi Marinov Marinov, g.marinov@ltu.bg
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Abstract

The aim of this study was to evaluate the effect of autologous platelet-rich plasma (PRP) gel combined with nanohydroxyapatite (HA) on bone regeneration in critical-sized diaphyseal defects in rabbits. Fourteen clinically healthy adult New Zealand White rabbits were divided into two groups: control (HA only, n=7) and experimental (HA+PRP, n=7). Standardized defects were created in the radius (≥1.5× bone diameter), and radiological, histological, histochemical, and immunohistochemical analyses were performed on days 30, 60, and 90 post-surgery. Radiographically, the PRP group demonstrated earlier bone bridge formation and complete defect filling by day 90, with significantly higher healing coefficients (0.64 vs 0.21; p<0.05). Histological evaluation revealed accelerated callus maturation and active osteogenesis with organized bone marrow in the PRP group, whereas the HA group showed incomplete union and persistent fibrous tissue. Immunohistochemical staining (CD34) confirmed neovascularization and hematopoietic precursor cell proliferation in the PRP-treated defects. The combined use of nanohydroxyapatite and PRP gel significantly enhanced osteoregeneration and shortened healing time in critical-sized bone defects.

Keywords: platelet-rich plasma, hydroxyapatite, bone regeneration, rabbit, histology

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Copyright  

©2026 Marinov G.M. This is an open-access article published under the terms of the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Conflict of Interest Statement

The authors declared that they have no financial or non-financial conflict of interest regarding authorship and publication of this article.

Citation Information

Macedonian Veterinary Review. Volume 49, Issue 2, Pages i-xiv, e-ISSN 1857-7415, p-ISSN 1409-7621, DOI:  https://doi.org/10.2478/macvetrev-2026-0021

The all content of the Macedonian Veterinary Review, except where otherwise noted, is licensed under a Creative Commons Attribution License.