Abstract: Musculoskeletal disorders are a major cause of lameness in horses, often necessitating innovative regenerative strategies to restore joint function and improve quality of life. This study investigated the effects of platelet-rich plasma (PRP), ozonized PRP, hyaluronic acid, paracetamol, and polyacrylamide hydrogel (NOLTREX) on the behavior of mesenchymal stem cells (MSCs) derived from equine synovial fluid. Synovial fluid samples were collected under strict cytological criteria to ensure viability, followed by in vitro expansion and phenotypic characterization of MSCs. Cultures were supplemented with the tested preparations, and cellular proliferation and viability were evaluated at 24 h, 72 h, and 7 days. PRP significantly promoted MSC proliferation in a time- and dose-dependent manner, with maximal effect at 10%. Hyaluronic acid stimulated growth, most pronounced at 1 mg/mL, while paracetamol induced a concentration-dependent proliferative response, strongest at 100 μg/mL. NOLTREX displayed a biphasic effect, initially inhibitory at high concentrations but stimulatory at 7 days. Ozonized PRP showed concentration-dependent redox activity, with lower doses maintaining viability and higher doses producing an initial suppression followed by delayed stimulation. Collectively, these findings support the therapeutic potential of PRP and related biologic preparations as intra-articular regenerative therapies in equine medicine, while underscoring the importance of dose optimization and standardized protocols to facilitate clinical translation.
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Overview
This study evaluated the effects of several treatments—including platelet-rich plasma (PRP), ozonized PRP, hyaluronic acid, paracetamol, and polyacrylamide hydrogel—on the growth and viability of mesenchymal stem cells (MSCs) derived from horse joint fluid.
The results demonstrated how these substances influence MSC proliferation and survival over time, providing insight into their potential use for joint regeneration in horses.
Background and Rationale
Musculoskeletal disorders are a leading cause of lameness in horses, impacting their mobility and quality of life.
Regenerative medicine, particularly using MSCs, offers promising strategies to repair joint damage and restore function.
Synovial fluid-derived MSCs are of special interest because they originate from the joint environment and may have higher relevance for intra-articular therapies.
Various biological and synthetic agents—such as PRP, ozonized PRP, hyaluronic acid, paracetamol, and polyacrylamide hydrogels—are proposed to support stem cell function or joint health, but their direct effects on MSCs need clarification.
Methods
Synovial fluid samples were collected from horses using strict cytological criteria to ensure viable MSC isolation.
Isolated MSCs were expanded in vitro, characterized phenotypically to confirm their identity.
MSC cultures were supplemented with different concentrations of:
Platelet-rich plasma (PRP)
Ozonized PRP (PRP treated with ozone for oxidizing effects)
Hyaluronic acid
Paracetamol (acetaminophen)
Polyacrylamide hydrogel (commercially known as NOLTREX)
Proliferation and viability were assessed at three time points: 24 hours, 72 hours, and 7 days post-treatment.
Key Findings
PRP:
Significantly stimulated MSC proliferation in both a time- and dose-dependent manner.
10% concentration produced the maximum proliferative effect.
Hyaluronic Acid:
Induced growth stimulation, especially notable at 1 mg/mL concentration.
Paracetamol:
Caused a concentration-dependent increase in proliferation.
Strongest proliferative effect observed at 100 μg/mL.
Higher doses caused early suppression followed by delayed stimulation of proliferation.
Interpretation and Clinical Implications
PRP and related biologic agents have demonstrated the capacity to modulate MSC behavior positively, suggesting utility as regenerative intra-articular therapies for equine joint diseases.
Hyaluronic acid and paracetamol also support MSC proliferation but their mechanisms may differ, as hyaluronic acid is a natural joint lubricant and paracetamol is commonly a pain reliever with some effects on cell metabolism.
The biphasic profile of NOLTREX highlights the importance of dosage and timing in therapeutic applications, indicating that immediate effects may differ from long-term outcomes.
Ozonized PRP’s redox effects suggest potential for controlled oxidative modulation of MSCs, but precise dosing is critical to avoid cytotoxicity.
The findings emphasize the need for optimized dosing protocols and standardization to maximize therapeutic benefits and ensure safety when translating these treatments to clinical practice.
Conclusions
The study provides evidence supporting the use of PRP, ozonized PRP, hyaluronic acid, paracetamol, and polyacrylamide hydrogel as modulators of equine synovial fluid-derived MSCs.
These agents have distinct and concentration-dependent effects on MSC proliferation and viability, which can inform the development of effective regenerative therapies for equine musculoskeletal disorders.
Future work should focus on clinical trials to validate these in vitro findings and establish guidelines for their safe and effective application in veterinary medicine.
Cite This Article
APA
Bungărdean D, Pall E, Daradics Z, Popescu M, Tripon MA, Lupșan AF, Crecan CM, Morar IA, Nicolescu A, Bora FD, Marcus I.
(2025).
In Vitro Effects of PRP, Ozonized PRP, Hyaluronic Acid, Paracetamol, and Polyacrylamide on Equine Synovial Fluid-Derived Mesenchymal Stem Cells.
Life (Basel), 15(10), 1558.
https://doi.org/10.3390/life15101558
Department of Pathophysiology, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine (UASVM) Cluj-Napoca, Mănăştur Street 3-5, 400372 Cluj-Napoca, Romania.
Pall, Emoke
Department of Infectious Diseases, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca, Calea Mănăştur nr. 3-5, 400372 Cluj-Napoca, Romania.
Daradics, Zsofia
Department of Internal Medicine, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine (UASVM) Cluj-Napoca, Mănăştur Street 3-5, 400372 Cluj-Napoca, Romania.
Popescu, Maria
Equine Clinic, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine (UASVM) Cluj-Napoca, Mănăştur Street 3-5, 400372 Cluj-Napoca, Romania.
Tripon, Mirela Alexandra
Department of Reproduction, Obstetrics and Veterinary Gynecology, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine (UASVM) Cluj-Napoca, Mănăştur Street 3-5, 400372 Cluj-Napoca, Romania.
Lupșan, Alexandru Florin
Department of Anesthesiology and Surgery, University of Agricultural Sciences and Veterinary Medicine (UASVM) Cluj-Napoca, Mănăştur Street 3-5, 400372 Cluj-Napoca, Romania.
Crecan, Cristian Mihăiță
Department of Anesthesiology and Surgery, University of Agricultural Sciences and Veterinary Medicine (UASVM) Cluj-Napoca, Mănăştur Street 3-5, 400372 Cluj-Napoca, Romania.
Morar, Ianu Adrian
Department of Reproduction, Obstetrics and Veterinary Gynecology, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine (UASVM) Cluj-Napoca, Mănăştur Street 3-5, 400372 Cluj-Napoca, Romania.
Nicolescu, Alexandru
Laboratory of Chromatography, Advanced Horticultural Research Institute of Transylvania, Faculty of Horticulture and Business for Rural Development, University of Agricultural Sciences and Veterinary Medicine, 400372 Cluj-Napoca, Romania.
Bora, Florin Dumitru
Laboratory of Chromatography, Advanced Horticultural Research Institute of Transylvania, Faculty of Horticulture and Business for Rural Development, University of Agricultural Sciences and Veterinary Medicine, 400372 Cluj-Napoca, Romania.
Viticulture and Oenology Department, Advanced Horticultural Research Institute of Transylvania, Faculty of Horticulture and Business in Rural Development, University of Agricultural Sciences and Veterinary Medicine (UASVM) Cluj-Napoca, Mănăştur Street 3-5, 400372 Cluj-Napoca, Romania.
Marcus, Ioan
Department of Pathophysiology, Faculty of Veterinary Medicine, University of Agricultural Sciences and Veterinary Medicine (UASVM) Cluj-Napoca, Mănăştur Street 3-5, 400372 Cluj-Napoca, Romania.
Sakata R, Reddi AH. Platelet-Rich Plasma Modulates Actions on Articular Cartilage Lubrication and Regeneration. Tissue Eng. Part B Rev. 2016;22:408–419.
Zhu Y, Yuan M, Meng HY, Wang AY, Guo QY, Wang Y, Peng J. Basic Science and Clinical Application of Platelet-Rich Plasma for Cartilage Defects and Osteoarthritis: A Review. Osteoarthr. Cartil. 2013;21:1627–1637.
Fotouhi A, Maleki A, Dolati S, Aghebati-Maleki A, Aghebati-Maleki L. Platelet Rich Plasma, Stromal Vascular Fraction and Autologous Conditioned Serum in Treatment of Knee Osteoarthritis. Biomed. Pharmacother. 2018;104:652–660.
Tjandra KC, Novriansyah R, Sudiasa INS, Ar A, Rahmawati NAD, Dilogo IH. Modified Mesenchymal Stem Cell, Platelet-Rich Plasma, and Hyaluronic Acid Intervention in Early Stage Osteoarthritis: A Systematic Review, Meta-Analysis, and Meta-Regression of Arthroscopic-Guided Intra-Articular Approaches.. PLoS ONE 2024;19:e0295876.
Dernek B, Kesiktas FN. Efficacy of Combined Ozone and Platelet-Rich-Plasma Treatment versus Platelet-Rich-Plasma Treatment Alone in Early Stage Knee Osteoarthritis.. J. Back Musculoskelet. Rehabil. 2019;32:305–311.
Vinod E, Padmaja K, Ramasamy B, Sathishkumar S. Systematic Review of Articular Cartilage Derived Chondroprogenitors for Cartilage Repair in Animal Models.. J. Orthop. 2023;35:43–53.
Hauschild G., Geburek F., Gosheger G., Eveslage M., Serrano D., Streitbürger A., Johannlükens S., Menzel D., Mischke R.. Short Term Storage Stability at Room Temperature of Two Different Platelet-Rich Plasma Preparations from Equine Donors and Potential Impact on Growth Factor Concentrations. BMC Vet. Res. 2016;13:7.
Yang X., Zhong Y., Wang D., Lu Z.. A Simple Colorimetric Method for Viable Bacteria Detection Based on Cell Counting Kit-8. Anal. Methods 2021;13:5211–5215.
Rinnovati R., Bonelli F., Tognetti R., Gallo C., Bassini R.F., Marchetti V., Sgorbini M.. Effect of Repeated Arthrocentesis on Cytology of Synovial Fluid. J. Equine Vet. Sci. 2017;57:112–115.
Jiang D., Muschhammer J., Qi Y., Kügler A., de Vries J.C., Saffarzadeh M., Sindrilaru A., Vander Beken S., Wlaschek M., Kluth M.A.. Suppression of Neutrophil-Mediated Tissue Damage—A Novel Skill of Mesenchymal Stem Cells. Stem Cells 2016;34:2393–2406.
Fiala-Rechsteiner S.M., Amaral M.G., Cruz L.A., Rodrigues R.F., Pimentel A.M., Mattos R.C.. Inflammatory Lesions in the Oviducts and Its Relationship With Endometrial Inflammation and Ovarian Activity in Criollo Mares. J. Equine Vet. Sci. 2015;35:731–734.
Soares C.S., Babo P.S., Reis R.L., Carvalho P.P., Gomes M.E.. Platelet-Derived Products in Veterinary Medicine: A New Trend or an Effective Therapy?. Trends Biotechnol. 2021;39:225–243.
Naor D.. Editorial: Interaction Between Hyaluronic Acid and Its Receptors (CD44, RHAMM) Regulates the Activity of Inflammation and Cancer. Front. Immunol. 2016;7:00039.
Almaawi A., Wang H.T., Ciobanu O., Rowas S.A.L., Rampersad S., Antoniou J., Mwale F.. Effect of Acetaminophen and Nonsteroidal Anti-Inflammatory Drugs on Gene Expression of Mesenchymal Stem Cells. Tissue Eng. Part A 2013;19:1039–1046.
Wang X., Wu Q., Liu A., Anadón A., Rodríguez J.-L., Martínez-Larrañaga M.-R., Yuan Z., Martínez M.-A.. Paracetamol: Overdose-Induced Oxidative Stress Toxicity, Metabolism, and Protective Effects of Various Compounds in Vivo and in Vitro. Drug Metab. Rev. 2017;49:395–437.
Wang P., Cui Y., Wang J., Liu D., Tian Y., Liu K., Wang X., Liu L., He Y., Pei Y.. Mesenchymal Stem Cells Protect against Acetaminophen Hepatotoxicity by Secreting Regenerative Cytokine Hepatocyte Growth Factor. Stem Cell Res. Ther. 2022;13:94.
Yiang G., Yu Y., Lin K., Chen J., Chang W., Wei C.. Acetaminophen Induces JNK/P38 Signaling and Activates the Caspase-9-3-Dependent Cell Death Pathway in Human Mesenchymal Stem Cells. Int. J. Mol. Med. 2015;36:485–492.