effect of microcurrent therapy on repair of induced tendon injury in albino rat: possible role of endogenous stem cells

ABSTRACT

Tendon repair involves a slow repair process, which results in inferior repair of tissue and failure to obtain full active range of motion. Microcurrent therapy [MCT] is a new therapy after arthroplasty. Stem cells with capacity of self-renewal are ideal for tissue engineering. The present work aimed at investigating the effect of MCT and the possible role of endogenous stem cells in repair of induced tendon injury in albino rat. Twenty-four male albino rats were classified into Control group, tenotomy group, 5 rats were sacrificed 2 weeks and 5 rats sacrificed 4 weeks following achillis tendon injury [Subgroups IIa and IIb respectively]. MCT group of 10 rats subjected to tendon injury followed by MCT, 5 rats sacrificed 2 weeks and 5 rats sacrificed 4 weeks following MCT [Subgroups IIIa and IIIb respectively]. Tendon sections were stained with H and E and CD44 and CD105 immunostains. A morphometric study was performed. Subgroup IIa demonstrated multiple areas of widely separated collagen fibers, infiltrating cells and multiple congested vessels. Subgroup IIb showed multiple areas of disorganized collagen bundles, less infiltrating cells and few congested vessels. MCT subgroup IIIa revealed some areas of parallel collagen bundles, some infiltrating cells and some dilated congested vessels. MCT subgroup IIIb showed multiple areas of parallel collagen bundles, few infiltrating cells and occasional congested vessels. CD44 +ve and CD105 +ve cells were seen among disorganized, parallel collagen fibers and inside blood vessels. A significant increase in the area of regenerated collagen bundles was recorded in MCT subgroup IIIb. The area% of CD44 +ve and CD105 +ve MSCs denoted a significant increase in MCT subgroup IIIa. MCT activated endogenous bone marrow derived MSCs migration to the injured achillis tendon, which stimulated tendon repair following induced tenotomy