Cell engraftment, vascularization, and inflammation after treatment of equine distal limb wounds with endothelial colony forming cells encapsulated within hydrogel microspheres.

The research article describes a study in which researchers examined the therapeutic potential of endothelial colony forming cells (ECFCs) encapsulated in hydrogel microspheres for treating leg wounds in horses, particularly assessing their effects on blood supply, wound vascularization, and inflammation.

Research Context and Objectives

• The researchers were investigating the possible therapeutic uses of ECFCs for treating conditions with poor blood supply, such as wounds on the distal limbs of horses.
• ECFCs were encapsulated in hydrogel microspheres to ensure their survival and effective localization, potentially improving neovascularization (new blood vessel formation) and healing.
• The study aimed to track the location of these cells once they were injected into the wounds, and to evaluate how the treatment affected vascularization and the inflammatory response – two crucial aspects of wound healing.

Research Methodology

• Autologous ECFCs (those derived from the horses themselves) were isolated and marked with quantum nanodots (QD) for tracking.
• The researchers created full-thickness dermal wounds on each horse’s distal limb and injected these with various treatments including empty microspheres, serum, naked ECFCs (i.e., not encapsulated), or ECFCs encapsulated in microspheres (ECFC/MS).
• To understand the effects of the treatments, the researchers induced different categories of changes, such as wound surface area, the formation of granulation tissue, thermography, collagen density staining, and immunohistochemical staining for endothelial (blood vessel lining) and inflammatory cells.

Research Findings

• A significant observation was that ECFCs were located near and within newly formed blood vessels up to three weeks post-injection, suggesting the cells were functioning as intended.
• The ECFC and ECFC/MS treatment groups demonstrated the highest quantity of new blood vessels at the wound periphery during the first week, potentially indicating improved vascularization.
• There was a decreased density of neutrophils (a type of white blood cell involved in inflammation) and macrophages (cells that engulf and digest cellular debris) in wounds treated with ECFCs and ECFC/MS at the 4-week mark. This suggests that these treatments might help control inflammation during the healing process.
• No other significant effects were discovered in relation to other measured parameters of the study.

Research Conclusion

• The researchers found that injecting microsphere-encapsulated ECFCs was practical and well-tolerated in a clinical setting.
• Overall, the study suggests that the use of ECFCs may have positive effects on blood vessel density and wound inflammation, which warrants further investigation.