Fidgetin-Like 2 siRNA Enhances the Wound Healing Capability of a Surfactant Polymer Dressing

Abstract

Microtubules (MTs) are intracellular polymers that provide structure to the cell, serve as railways for intracellular transport, and regulate many cellular activities, including cell migration. The dynamicity and function of the MT cytoskeleton are determined in large part by its regulatory proteins, including the recently discovered MT severing enzyme Fidgetin-like 2 (FL2). Downregulation of FL2 expression with small interfering RNA (siRNA) results in a more than twofold increase in cell migration rate in vitro as well as translates into improved wound-healing outcomes in in vivo mouse models. Here we utilized a commercially available surfactant polymer dressing (SPD) as a vehicle to deliver FL2 siRNA. To this end we incorporated collagen microparticles containing FL2 siRNA into SPD (SPD-FL2-siRNA) for direct application to the injury site. Topical application of SPD-FL2 siRNA to murine models of full-thickness excision wounds and full-thickness burn wounds resulted in significant improvements in the rate and quality of wound healing, as measured clinically and histologically, compared with controls. Wound healing occurred more rapidly and with high fidelity, resulting in properly organized collagen substructure. Taken together, these findings indicate that the incorporation of FL2 siRNA into existing treatment options is a promising avenue to improve wound outcomes.

A Virus-Derived Immune Modulating Serpin Accelerates Wound Closure with Improved Collagen Remodeling

“…Collagen I is an important factor in angiogenic sprouting and is associated with increased and improved vessel formation [82]. In contrast, increased deposition of collagen III reduces the density of blood vessels at sites of wound healing [83,84]. Here, we have further demonstrated that Serp-1 treatment is associated with more organized collagen deposition (Masson’s trichrome), as well as more collagen maturation (Herovici’s polychrome).…”

Recombinant Myxoma Virus-Derived Immune Modulator M-T7 Accelerates Cutaneous Wound Healing and Improves Tissue Remodeling

“…Here, we found that in addition to accelerating wound healing, recombinant M-T7 also resulted in earlier, improved collagen maturation, as determined by quantification with Herovici’s polychrome in a metric we term the “Herovici Ratio” ( Figure 2 ). A similar quantification of Type III:I collagen was observed by O’Rourke and colleagues in their investigation of accelerated wound healing by surfactant polymer dressings containing siRNA to Fidgetin-Like 2, with the authors noting increased red Type I collagen, illustrating higher-fidelity healing [ 56 ].…”

A Novel Therapeutic Approach to Corneal Alkaline Burn Model by Targeting Fidgetin-Like 2, a Microtubule Regulator

“…This occurs within the RNA interference (RNAi) pathway within the cell. Whereas siRNA-based therapies have shown some promise for treating a wide range of maladies, including wound closure, 11 – 13 the effective delivery of therapeutic siRNA has proven difficult in many circumstances. The siRNA is a relatively large and negatively charged molecule, making it impermeable to cellular membranes.…”

“…As a result, silencing FL2 with siRNA (FL2-siRNA) promotes cell motility in vitro and wound healing in animal models, such as dermal excision and burn wounds in mice. 12 , 13 …”