Microcurrent and adipose-derived stem cells modulate genes expression involved in the structural recovery of transected tendon of rats

Advancing Chronic Wound Healing through Electrical Stimulation and Adipose-Derived Stem Cells

Chronic cutaneous wounds are a major clinical challenge worldwide due to delayed healing, recurrent infections, and resistance to conventional therapies. Adipose-derived stem cells (ASCs) have shown promise as a cell-based therapy, but their therapeutic efficacy is often compromised by the harsh microenvironment of chronic wounds. Recent advances in bioengineering, particularly the application of electrical stimulation (ES), offer an innovative approach to enhancing the regenerative properties of ASCs. By restoring the natural electrical current in the wound, ES provides a strong stimulus to the cells involved in healing, thereby accelerating the overall wound-healing process. Recent studies show that ASCs can be significantly activated by ES, which increases their viability, proliferation, migration, and secretory capacity, all of which are crucial for the proper healing of chronic wounds. This review examines the synergistic effects of ES and ASCs on wound healing, focusing on the biological mechanisms involved. The review also highlights novel self-powered systems and other emerging technologies such as advanced conductive materials and devices that promise to improve the clinical translation of ES-based treatments. By summarizing the current state of knowledge, this review aims to provide a framework for future research and clinical application of ES and ASCs in wound care.

Molecular Biological Verification of the Healing Effect of Biphasic Microcurrent Electrical Stimulation in Model Rats of Skin Abrasion

In this study, we investigated the effect of biphasic microcurrent electrical stimulation (b-MES) on the epidermal healing process using a rat model of skin abrasion. We analyzed the expression levels of growth factors [fibroblast growth factor 2 (FGF2) and epidermal growth factor (EGF)] and keratin subtypes (K10) in both the b-MES and control groups at different time points after wounding. The b-MES group showed a significantly accelerated healing process of the epithelial tissue, resulting in more consistent healing as compared to the control group. A molecular biological analysis showed that the FGF2 mRNA expression level on Day 2 after wounding was significantly higher in the b-MES group, whereas the EGF mRNA expression level on Days 1, 2, and 4 after wounding was significantly lower in the b-MES group. Additionally, the K10 mRNA expression level on Days 1 and 2 after wounding was significantly higher in the b-MES group. Our study findings suggest that b-MES facilitates wound healing by regulating the growth factors. However, the precise mechanisms underlying these effects remain to be fully elucidated. Further research is needed to fully understand the therapeutic potential of b-MES and its applications in clinical setting. Clinically, m-MES requires shunting due to residual electrical charge at the application site. However, b-MES alternates polarity, leaving no charge at the site of application. Therefore, b-MES also has the advantage of being safer and allowing treatment for longer periods of time.

Electrospun heparin-loaded nano-fiber sutures for the amelioration of achilles tendon rupture regeneration: in vivo evaluation

Peritendinous blood circulation improvement is a challenge to promote the healing of ruptured tendons in clinical treatment. Although electrospun membranes or scaffolds enable the reduction of complications such as adhesion, however, low efficiency, toxicity issues, the loss of biological activity, and complex electrospinning techniques are all bottlenecks of these systems. Improving the blood supply is crucial for their successful use, which involves promoting the metabolism and nutrient absorption in tendons. Here, a multifunctional, structurally simple strategy involving heparin-loaded sutures (PPH) that are clinically applicable is reported, in the form of electrospun core-shell nanofibers, with the ability to perform sustained release of anticoagulants heparin (verified in our previous publication) for the improvement of the healing of Achilles tendon. The morphology and diameter distribution of the collagen fiber in the PPH group are closely related to the health of the Achilles tendon than those of commercial sutures (CS). The in vivo results of the total collagen content and the expression of collagen type I in the PPH group are more than those of the CS group. After 6 weeks of culture, the tensile strength of the PPH group shows no significant difference compared to the healthy group. The data obtained in this study improves the current understanding on the regeneration of ruptured tendons and presents a promising strategy for clinical treatment.

Electrical therapies act on the Ca2+ /CaM signaling pathway to enhance bone regeneration with bioactive glass [S53P4] and allogeneic grafts

This study aimed to investigate the application of low-intensity electrostimulation (ES) and electromagnetic stimulation (EM) associated with bioactive glass (BG) or allogeneic grafts (BB) in bone regeneration. A cell viability test on osteoblasts (UMR-106) was performed in the presence of BB and BG grafts associated with ES (10 μA/5 min) and EM (500 Hz/2 min). Critical defects (25 mm² ) in calvaria were generated in male Wistar rats, and bone regeneration was evaluated on the 30th, 60th, and 120th days after surgery. Cell proliferation increased with the application of ES in both grafts and after EM with BG. Bone remodeling was more effective using the allogeneic graft in both therapies, with increased angiogenesis, osteoblast proliferation, and OPN expression in the BB + EM group. A higher number of osteoblasts and osteoclasts, and an increase in bone sialoprotein, Runx-2, and Opn gene expression were found in the BB + ES group. The BG graft associated with EM therapy had an increased proliferation of osteoblasts and increased expression of Runx-2 and Opn. Groups that had BG and ES therapy had increased numbers of osteoblasts, osteoclasts, and increased OPN expression. The expression of voltage-gated calcium channels increased in groups with ES, while calmodulin expression increased in therapies without grafting. ES and EM therapies favored the repair of bone defects upon grafting by improving angiogenesis, osteogenic gene expression, and tissue reorganization. Despite activating different pathways, both therapies increased the intracellular concentrations of calmodulin, leading to cell proliferation and bone regeneration.

Influence of microcurrent on the modulation of remodelling genes in a wound healing assay

The literature has shown the beneficial effects of microcurrent (MC) therapy on tissue repair. We investigated if the application of MC at 10 μA/90 s could modulate the expression of remodeling genes transforming growth factor beta (Tgfb), connective tissue growth factor (Ctgf), insulin-like growth factor 1 (Igf1), tenascin C (Tnc), Fibronectin (Fn1), Scleraxis (Scx), Fibromodulin (Fmod) and tenomodulin in NIH/3T3 fibroblasts in a wound healing assay. The cell migration was analyzed between days 0 and 4 in both fibroblasts (F) and fibroblasts + MC (F+MC) groups. On the 4th day, cell viability and gene expression were also analyzed after daily MC application. Higher expression of Ctgf and lower expression of Tnc and Fmod, respectively, were observed in the F+MC group in relation to F group (p < 0.05), and no difference was observed between the groups for the genes Tgfb, Fn1 and Scx. In cell migration, a higher number of cells in the scratch region was observed in group F+MC (p < 0.05) compared to group F on the 4th day, and the cell viability assay showed no difference between the groups. In conclusion, MC therapy at an intensity/time of 10 μA/90 s with 4 daily applications did not affect cell viability, stimulated fibroblasts migration with the involvement of Ctgf, and reduced the Tnc and Fmod expression.