A pilot study to demonstrate the paracrine effect of equine, adult allogenic mesenchymal stem cells in vitro, with a potential for healing of experimentally-created, equine thoracic wounds in vivo

Preliminary in vivo investigation of the mesenchymal stromal cell secretome as a novel treatment for methicillin-resistant Staphylococcus aureus in equine skin wounds

OBJECTIVE

We aimed to study the antimicrobial and pro-healing potential of equine mesenchymal stromal cell secreted products (i.e. secretome), collected as conditioned media (mesenchymal stromal cell-conditioned media, MSC CM), in a novel in vivo model of methicillin-resistant Staphylococcus aureus (MRSA)-inoculated equine thorax wounds.

STUDY DESIGN

Prospective in vivo study.

ANIMALS

Two Thoroughbred geldings.

METHODS

Six full-thickness cutaneous wounds were created bilaterally on the dorsal thorax of two horses (n = 12 wounds/horse). Wounds on the left thoraces were inoculated with MRSA on day 0. All wounds were then treated with either mupirocin ointment, MSC CM, or vehicle control (n = 4 wounds per group) once daily for 3 days. Photographs were taken to quantify wound scores and sizes, as well as samples to determine bacterial colony forming units (CFUs), at days 0, 1, 2, 3, 7, 14, 21, and 28. The wound edge was biopsied on days 0, 7, and 28, and scored histologically.

RESULTS

Inoculated wounds had more bacterial CFUs at day 1 (p < .0001) and were larger in size at day 28 (p = .0009) than noninoculated wounds. Mupirocin-treated wounds were smaller than MSC CM and vehicle control-treated wounds at day 28 (p = .003). Mesenchymal stromal cell-conditioned media did not affect CFU numbers in inoculated and noninoculated wounds. Moreover, MSC CM did not affect the parameters of wound size or gross or microscopic wound scores over time.

CONCLUSION

Mesenchymal stromal cell-conditioned media did not exhibit antimicrobial or pro-healing properties in the current study; however, the in vivo model of inoculated equine thorax wounds requires further optimization.

CLINICAL SIGNIFICANCE

This pilot study contributes to a growing understanding of the equine MSC secretome as an antimicrobial and pro-healing therapeutic for equine wounds.

The Best Protocol to Treat Equine Skin Wounds by Second Intention Healing: A Scoping Review of the Literature

Equine skin wound treatment continues to be a challenge for veterinarians. Despite being a frequent practice, it remains difficult to choose an evidence-based treatment protocol. This study aimed to comprehensively explore the literature and provide a scoping review of therapeutic strategies for equine skin wounds and identify knowledge gaps and opportunities for future research. This review was conducted using specific criteria to select literature that described methods to manage second intention wound healing. After removing duplicates and screening papers for suitability, 81 manuscripts were included for data extraction. Of these, 59 articles were experimental studies, 10 were case reports, 9 were case series, and 3 were clinical studies. The most frequent wound location was the distal limbs. Macroscopic assessment was the main tool used to evaluate treatment effectiveness. All of the case reports, case series, and clinical studies reported positive outcomes with regard to the treatment used, while only 36% of the experimental studies found significant healing improvement in treated wounds compared to control groups. It was found that there are many treatments that have exhibited controversial results, and there exists a lack of evidence for the adoption of specific treatment protocols.

Curcumin-infused nanostructured lipid carriers: a promising strategy for enhancing skin regeneration and combating microbial infection

BACKGROUND

Curcumin is a biomolecule that can be extracted from the Curcuma longa that has been shown to have the potential to aid skin wound healing. It has been studied for its anti-inflammatory and antioxidant properties, which may help to reduce swelling and promote tissue repair. However, curcumin has low solubility in water, which can limit its absorption and bioavailability. Encapsulating it in lipid nanoparticles may help to increase its absorption, leading to improved bioavailability.

METHODS

Curcumin-loaded nanostructure lipid nanocarriers (CURC-NLCs) were prepared and characterized. Also, the phenolic, flavonoid contents, antioxidant and antimicrobial efficacy against gram-positive and gram-negative bacteria were investigated. Furthermore, in vivo rabbit animal model was used to test its regenerative capacity and wound-healing efficiency.

RESULTS

The CURC-NLCs significantly increased the content of phenolic and flavonoid compounds compared to curcumin, resulting in a dramatic increase in antioxidant activity. CURC-NLCs also showed a potent inhibitory effect on Gram-positive, Gram-negative, and fungi, two times higher than curcumin. CURC-NLCs showed a higher potential to fasten the wound healing of full-thickness skin injuries as it resulted in 1.15- and 1.9-fold higher wound closure at the first week of injury compared to curcumin and control, respectively (p < 0.0001).

CONCLUSION

These results suggest that CURC-NLCs have an excellent potential to promote skin regeneration, which could be attributed to its antioxidant and broad-spectrum antimicrobial effect.

Equine mesenchymal stem cell derived extracellular vesicle immunopathology biomarker discovery

The use of mesenchymal stem cells (MSCs) in human and veterinary clinical applications has become a subject of increasing importance due to their roles in immunomodulation and regenerative processes. MSCs are especially relevant in equine medicine because they may have the ability to treat prevalent musculoskeletal disorders, among other conditions. However, recent evidence suggests that the components secreted by MSCs, particularly extracellular vesicles (EVs), are responsible for these properties. EVs contain proteins and nucleic acids, which possess an active role in intercellular communication and can be used as therapeutics. However, because the intersection of equine veterinary medicine with EVs remains a relatively new field, there is a demand to identify biomarkers that can discern and enrich for therapeutic EVs, progressing their clinical efficacy. In this study, we identified and characterized 84 miRNAs, between three equine donors involved in immunomodulation in cell and EV subjects. We discovered distinct groups of shared miRNAs, like miR-21-5p and miR-451a, that are abundant and enriched between the donors' EVs, respectively. By mapping and comparing the MSC-EV miRNA expression, we discovered many pathways that are involved in immunomodulation and tissue regenerative processes related to equine clinical applications. Therefore, the miRNAs highlighted in this article can be used as valuable biomarkers for screening MSC-derived EVs for potential equine therapy.