Current use of biologic therapies for musculoskeletal disease: A survey of board-certified equine specialists.

OBJECTIVE: To evaluate the use of mesenchymal stem cells (MSCs), autologous conditioned serum (ACS), platelet-rich plasma (PRP), and autologous protein solution (APS) for the treatment of equine musculoskeletal disease by diplomates of the American College of Veterinary Surgery (ACVS), and American College of Veterinary Sports Medicine and Rehabilitation (ACVSMR). STUDY DESIGN: Cross-sectional study. SAMPLE POPULATION: Diplomates (n = 423). METHODS: An email link was sent to ACVS and ACVMR diplomates. A survey contained 59 questions regarding demographics, as well as indications, frequency, adverse effects, and limitations of use. Responses were analyzed using Fisher's exact test. RESULTS: One hundred and fifty four surveys were analyzed. Years in practice and type of practice were not associated with biologic therapy use. PRP was the most used therapy (120/137; 87.5%). PRP and MSCs were most often administered intralesionally while ACS and APS were most often administered intra-articularly. ACS (50/104; 48.1%) treatment was repeated commonly within 2 weeks of initial injection. MSCs (39/90; 43.3%) and PRP (38/100; 38%) were commonly repeated 1-2 months after initial injection and APS was typically repeated >4 months after initial injection (21/53; 39.6%). Local inflammation and expense were the most common adverse effect and limitation of use. CONCLUSION: Diplomates most commonly utilized PRP and MSC intralesionally for soft-tissue injuries, and ACS and ACP intra-articularly for joint injury. Protocols for repeated administration varied widely. Local inflammation was a clinical concern with the use of biologics. CLINICAL SIGNIFICANCE: Biologic therapies are used commonly by ACVS and ACVSMR diplomates for soft tissue and joint disease.

In Vitro Effects of High-Intensity Laser Photobiomodulation on Equine Bone Marrow-Derived Mesenchymal Stem Cell Viability and Cytokine Expression.

OBJECTIVE: This study aimed to examine the influence of neodymium-doped yttrium aluminum garnet (Nd:YAG) laser irradiation on equine bone marrow-derived mesenchymal stem cell (MSC) viability, proliferation, and cytokine expression in vitro. BACKGROUND: Photobiomodulation of cells using monochromatic light is a technique designed to influence cellular processes. Previous studies have shown dose-dependent effects of low-level laser irradiation on cell proliferation and cytokine expression in a range of cell types and species. Evidence for the influence of 1064 nm wavelength near-infrared irradiation on MSCs is sparse, and high-energy doses have shown inhibitory effects. METHODS: MSC cultures from six horses were exposed to 1064 nm irradiation with an energy density of 9.77 J/cm2 and a mean output power of 13.0 W for 10 sec. MSC viability and proliferation were evaluated through flow cytometry and real-time live cell analysis. Gene expression and cytokine production in the first 24 h after irradiation were analyzed through polymerase chain reaction (PCR), multiplex assay, and enzyme-linked immunosorbent assay. RESULTS: No difference in viability was detected between irradiated and control MSCs. Irradiated cells demonstrated slightly lower proliferation rates, but remained within 3.5% confluence of control cells. Twenty-four hours after irradiation, irradiated MSCs demonstrated a significant increase in expression of interleukin (IL)-10 and vascular endothelial growth factor (VEGF) compared with control MSCs. CONCLUSIONS: Under these irradiation parameters, equine MSCs remained viable and expressed increased concentrations of IL-10 and VEGF. IL-10 has an anti-inflammatory action by inhibiting the synthesis of proinflammatory cytokines at the transcriptional level. This response to 1064 nm irradiation shows promise in the photobiomodulation of MSCs to enhance their therapeutic properties.

Osteoblastic differentiation of human and equine adult bone marrow-derived mesenchymal stem cells when BMP-2 or BMP-7 homodimer genetic modification is compared to BMP-2/7 heterodimer genetic modification in the presence and absence of dexamethasone.

Bone marrow-derived mesenchymal stem cells (BMDMSCs) have been targeted for use in enhancement of bone healing; and their osteogenic potential may be further augmented by genes encoding bone morphogenetic proteins (BMP's). The purpose of this study was to compare the effect of genetic modification of human and equine BMDMSCs with BMP-2 or -7 or BMP-2 and -7 on their osteoblastogenic differentiation in the presence or absence of dexamethasone. The BMDMSCs were harvested from the iliac crest of three human donors and tuber coxae of three equine donors. Monolayer cells were genetically modified using adenovirus vectors encoding BMP-2, -7 or both and cultured in the presence or absence of dexamethasone. Expression of BMPs was confirmed by enzyme linked immunosorbent assay (ELISA). To evaluate osteoblastic differentiation, cellular morphology was assessed every other day and expression and secretion of alkaline phosphatase (ALP), as well as expression levels of osteonectin (OSTN), osteocalcin (OCN), and runt-related transcription factor-2 (Runx2) were measured for up to 14 days. Human and equine BMDMSCs showed a capacity for osteogenic differentiation regardless of genetic modification or dexamethasone supplementation. Dexamethasone supplementation was more important for osteoblastogenic differentiation of equine BMDMSCs than human BMDMSCs. Genetic modification of BMDMSCs increased ALP secretion with AdBMP-2 homodimer having the greatest effect in both human and equine cells compared to AdBMP 7 or AdBMP 2/7. BMP protein elution rates reached their maximal concentration between day 4 and 8 and remained relatively stable thereafter, suggesting that genetically modified BMDMSCs could be useful for cell-based delivery of BMPs to a site of bone formation.