Regulatory effects of bio-intensity electric field on transformation of human skin fibroblasts / 中华烧伤杂志

Objective: To investigate the regulatory effects of bio-intensity electric field on the transformation of human skin fibroblasts (HSFs). Methods: The experimental research methods were used. HSFs were collected and divided into 200 mV/mm electric field group treated with 200 mV/mm electric field for 6 h and simulated electric field group placed in the electric field device without electricity for 6 h. Changes in morphology and arrangement of cells were observed in the living cell workstation; the number of cells at 0 and 6 h of treatment was recorded, and the rate of change in cell number was calculated; the direction of cell movement, movement velocity, and trajectory velocity within 3 h were observed and calculated (the number of samples was 34 in the simulated electric field group and 30 in 200 mV/mm electric field group in the aforementioned experiments); the protein expression of α-smooth muscle actin (α-SMA) in cells after 3 h of treatment was detected by immunofluorescence method (the number of sample was 3). HSFs were collected and divided into simulated electric field group placed in the electric field device without electricity for 3 h, and 100 mV/mm electric field group, 200 mV/mm electric field group, and 400 mV/mm electric field group which were treated with electric fields of corresponding intensities for 3 h. Besides, HSFs were divided into simulated electric field group placed in the electric field device without electricity for 6 h, and electric field treatment 1 h group, electric field treatment 3 h group, and electric field treatment 6 h group treated with 200 mV/mm electric field for corresponding time. The protein expressions of α-SMA and proliferating cell nuclear antigen (PCNA) were detected by Western blotting (the number of sample was 3). Data were statistically analyzed with Mann-Whitney U test, one-way analysis of variance, independent sample t test, and least significant difference test. Results: After 6 h of treatment, compared with that in simulated electric field group, the cells in 200 mV/mm electric field group were elongated in shape and locally adhered; the cells in simulated electric field group were randomly arranged, while the cells in 200 mV/mm electric field group were arranged in a regular longitudinal direction; the change rates in the number of cells in the two groups were similar (P>0.05). Within 3 h of treatment, the cells in 200 mV/mm electric field group had an obvious tendency to move toward the positive electrode, and the cells in simulated electric field group moved around the origin; compared with those in simulated electric field group, the movement velocity and trajectory velocity of the cells in 200 mV/mm electric field group were increased significantly (with Z values of -5.33 and -5.41, respectively, P<0.01), and the directionality was significantly enhanced (Z=-4.39, P<0.01). After 3 h of treatment, the protein expression of α-SMA of cells in 200 mV/mm electric field group was significantly higher than that in simulated electric field group (t=-9.81, P<0.01). After 3 h of treatment, the protein expressions of α-SMA of cells in 100 mV/mm electric field group, 200 mV/mm electric field group, and 400 mV/mm electric field group were 1.195±0.057, 1.606±0.041, and 1.616±0.039, respectively, which were significantly more than 0.649±0.028 in simulated electric field group (P<0.01). Compared with that in 100 mV/mm electric field group, the protein expressions of α-SMA of cells in 200 mV/mm electric field group and 400 mV/mm electric field group were significantly increased (P<0.01). The protein expressions of α-SMA of cells in electric field treatment 1 h group, electric field treatment 3 h group, and electric field treatment 6 h group were 0.730±0.032, 1.561±0.031, and 1.553±0.045, respectively, significantly more than 0.464±0.020 in simulated electric field group (P<0.01). Compared with that in electric field treatment 1 h group, the protein expressions of α-SMA in electric field treatment 3 h group and electric field treatment 6 h group were significantly increased (P<0.01). After 3 h of treatment, compared with that in simulated electric field group, the protein expressions of PCNA of cells in 100 mV/mm electric field group, 200 mV/mm electric field group, and 400 mV/mm electric field group were significantly decreased (P<0.05 or P<0.01); compared with that in 100 mV/mm electric field group, the protein expressions of PCNA of cells in 200 mV/mm electric field group and 400 mV/mm electric field group were significantly decreased (P<0.05 or P<0.01); compared with that in 200 mV/mm electric field group, the protein expression of PCNA of cells in 400 mV/mm electric field group was significantly decreased (P<0.01). Compared with that in simulated electric field group, the protein expressions of PCNA of cells in electric field treatment 1 h group, electric field treatment 3 h group, and electric field treatment 6 h group were significantly decreased (P<0.01); compared with that in electric field treatment 1 h group, the protein expressions of PCNA of cells in electric field treatment 3 h group and electric field treatment 6 h group were significantly decreased (P<0.05 or P<0.01); compared with that in electric field treatment 3 h group, the protein expression of PCNA of cells in electric field treatment 6 h group was significantly decreased (P<0.01). Conclusions: The bio-intensity electric field can induce the migration of HSFs and promote the transformation of fibroblasts to myofibroblasts, and the transformation displays certain dependence on the time and intensity of electric field.

Aesthetic reconstruction of the scar contracture deformity in chin and neck with expanded flaps based on the "MRIS" principle / 中华烧伤杂志

Objective: The surgical reconstruction strategy for scar contracture deformity in chin and neck was explored, aiming to obtain better aesthetic outcome. Methods: A retrospective observational study was conducted. From December 2017 to April 2021, 34 patients with scar contracture deformity in chin and neck after burns were hospitalized in the Department of Plastic Surgery of the First Affiliated Hospital of Army Medical University (the Third Military Medical University), aged 12-54 years, including 13 males and 21 females, 4 cases with chin affected only, 7 cases with neck affected only, and 23 cases with both chin and neck affected. The scar areas were 48-252 cm2. All the patients were treated by operation with expanded flaps, following the "MRIS" principle of matching of the color and thickness of the repair flaps (match), reconstructing of the aesthetic features of subunits (reconstruction), design of incision according to the plastic principle (incision), and prevention of the surgical incision scar (scar). The rectangular or kidney shaped skin and soft tissue expander (hereinafter referred to as the expander) with rated capacity of 80-400 mL was embedded in the first stage, which was routinely expanded to 3-5 times of the rated capacity of the expander. In the second stage, scar resection and expanded flap excision were performed to repair the secondary wound, and the flap donor site was sutured directly. The expansion ratio of the expander (with average value being calculated), the type of flaps used, the reconstruction of local aesthetic morphology, the appearance of postoperative incision, the survival of flap, and the situation of donor and recipient sites observed during follow-up were recorded. Results: Among the 34 patients, the average expansion ratio of the implanted expander was 3.82 times of the rated capacity of the expander. Three cases were repaired by the expanded local pedicled flap only, 19 cases by the expanded shoulder and/or chest perforator pedicled flap only, 10 cases by the expanded local pedicled flap combined with the expanded shoulder and/or chest perforator pedicled flap, and 2 cases by the expanded local pedicled flap combined with the expanded free flap of the second intercostal perforator of internal thoracic artery. After scar resection, the shapes of lower lip and chin-lip groove were reconstructed in 10 cases, chin process reconstruction and chin lengthening were performed in 16 cases, and the cervico-mental angle and mandibular margin contour were reconstructed in 28 cases. The surgical incision was concealed, most of which were located at the natural junction or turning point of the chin and neck subunits. The vertical incision of neck was Z-shaped or fishtail-shaped. All the expanded flaps in 34 patients survived after operation, of which 8 patients had minor necrosis at the edge or tip of the expanded flaps 1-3 days after operation and healed after dressing change. During the follow-up of 3-18 months, little difference in color and thickness between the expanded flap and the skin of chin and neck was observed, and the aesthetic shape of chin and neck was significantly improved, with mild scar hyperplasia of surgical incision. Conclusions: Reconstruction of scar contracture deformity in chin and neck by using expanded flaps based on the "MRIS" principle is beneficial to improve the quality of surgery and achieve better aesthetic outcome.