The effect of focal-adhesion micromanipulation in trauma and wound healing / 中华整形外科杂志

<p><b>OBJECTIVE</b>To explore the effect of focal-adhesion micromanipulation on the biological behavior of fibroblast.</p><p><b>METHODS</b>Micro-pot was made by microcontact printing. The molecules of constitutive protein was adhered on micro-pot by self-assemble of peptides. Skin fibroblasts were cultured on the membrane by self-made biomechanical cell culture for 2 weeks. Morphology observation and cell immunohistochemistry analysis was performed.</p><p><b>RESULTS</b>After 2 weeks, the morphology of the fibroblasts was diverse and more compliant. Cell immunohistochemistry analysis found that the expression of integrinbeta1, alpha5 and tensin was dramatically reduced.</p><p><b>CONCLUSIONS</b>The morphology and the biological behaviour of the fibroblasts in hypertrophic scar can be changed after micromanipulation of focal adhesion.</p>

Study on the mechanism of scar formation: epidermis template defect theory / 中华烧伤杂志

Dermal defection and the degree of its loss determine the natural process of wound healing, which is the key reason leading to excess scar hyperplasia. The function of tri-dimensional structure in dermis acts as a template to regulate the properties of reparative cells. The template structure induces the reparative cells to grow into the structure which changes the skin mechanic status on wound area. Also, the component of extracellular matrix can affect behaviours of fibroblasts negatively or positively, for the reason that the structure of dermal tissue has a permissive effect on the dermal components in regulating behaviours of reparative cells. Therefore, the behaviors of cells depend on the structure of the template. The suitable tri-dimensional structure of dermis facilitates normal cell cycling. The more the structure of dermis closed to its physiological status, the better the biological behaviors of cells act. Moreover, the integrity as well as the continuity of dermal tissue is the prerequisite for serving as a template. The damage to the integrity and the continuity of dermal tissue may be one of the key reasons to lead abnormal tissue repair and scar formation. Thus, we hypothesize that the loss of dermal template may be one of the mechanism of abnormal scar formation and propose the theory of extracellular matrix framework deficiency or destruction.

Study on the biological function of vascular endothelial cells in the hypertrophic scar / 中华烧伤杂志

<p><b>OBJECTIVE</b>To explore the biological function of vascular endothelial cells from hypertrophic scar, and to analyze the relationship between them.</p><p><b>METHODS</b>The samples from human hypertrophic scar and normal skin tissue were harvested for histological examination. Then vascular endothelial cells were purified and isolated from the samples, and the level of transforming growth factor (TGF) beta1, platelet derived growth factor (PDGF), endothelin1 (ET)-1, fibroblast growth factor (FGF)2 and vascular endothelial growth factor (VEGF) were determined in a single cell with ELISA.</p><p><b>RESULTS</b>Few capillary vessels were observed in normal skin under microscope, while an increased number of them were present in hypertrophic scar, with slender, tortuous in morphology and even occluded. The diameter of blood capillary in hypertrophic scar was tiny under electron microscope, and the exfoliation of endothelial cells was observed. The levels of TGF-beta1, PDGF, ET-1, bFGF and VEGF from vascular endothelial cells from hypertrophic scar were 60 +/- 8, 30 +/- 4, 0.12 +/- 0.03, 52 +/- 5, 18.1 +/- 1.2 microg/cell, respectively, which were obviously lower than those in normal skin (P < 0.05).</p><p><b>CONCLUSION</b>The biological function of vascular endothelial cells was attenuated in the hypertrophic scar, which mightbe the result of the production of large amounts of collagen in the scar tissue, as well as hypoxia.</p>

The influence of dermal template on the expressions of signal transduction protein Smad 3 and transforming growth factor beta1 and its receptor during wound healing process in patients with deep burns / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the influence of dermal template on the expressions of signal transduction protein Smad 3 and transforming growth factor beta1 and its receptor during wound healing process in patients with deep burns.</p><p><b>METHODS</b>Twenty burn patients with excision of full thickness burn in the extremities were enrolled in the study and divided into two groups, i.e. template interfering group (E, n = 20, grafting of dermal template [allogeneic acellular dermal matrix] with razor thin autoskin) and control group (C, n = 20, grafting of razor thin autoskin only). The contralateral side served as the self-control. Tissue samples from the burn wounds were harvested at 1, 2, 3 and 4 post-operative weeks (POW) for immunohistochemistry staining. The positive expression rates of TGF-beta1, TbetaRI, TbetaRII and Smad3 proteins were determined by image analysis system.</p><p><b>RESULTS</b>The positive expressions of TGFbeta1, TbetaRI, TbetaRII and signal transduction protein Smad 3 in the tissue samples in both groups could be identified during 1 approximately 4 POW, and they diminished thereafter with the process of wound healing. The expression rate of TGF-beta1 in E group was (13.08 +/- 4.65)% at 1 POW and (9.03 +/- 1.89)% at 4 POW. The positive expression rate of above indices in E group was obviously lower than that in C group in corresponding time points (P < 0.05).</p><p><b>CONCLUSION</b>The expression levels of TGFbeta1, TbetaRI, TbetaRII and Smad 3 protein in deep burn wounds could be lowered by mixed grafting of dermal template with razor thin autoskin, which might be beneficial in ameliorating of scar hyperplasia in the burn wound.</p>

The influence of dermal template application on the p53 gene expression and apoptosis during wound repairing in burn patients / 中华烧伤杂志

<p><b>OBJECTIVE</b>To observe dynamically the influence of the application of dermal template on the p53 gene expression and apoptosis during wound repairing in burn patients.</p><p><b>METHODS</b>Twenty burn patients were enrolled in the study and were divided into experiment (E, n = 11) and control (C, n = 9) groups. The escharectomy wounds in patients with 3rd degree burn in E group were covered with dermal template overlain with thin split-thickness autograft, while those in C group were covered with thin split-thickness autograft only. Specimens were harvested from wounds of both groups at 1st, 2nd, 3rd, 4th and 5th post operative week (POW). The P53 expression and the apoptosis were assessed respectively by immunohistochemistry and by TUNEL kit. The change in cell number was observed after HE staining.</p><p><b>RESULTS</b>The P53 expression increased gradually along with the wound healing process from 1st to 4th POW, which was significantly higher than that in C group at 2nd, 3rd, and 4th POW (P < 0.05), and it reached the peak at 4th POW. Fibroblasts underwent apoptosis at 1st POW in E group, while apoptosis of the endothelial cells occurred mainly at 2nd and 3rd POW. There was obvious difference in the rate of apoptosis between the two groups in 3rd and 4th POW (P < 0.05). The numbers of fibroblasts and vascular endothelial cells in E group were smaller than those in C group.</p><p><b>CONCLUSION</b>Application of dermal template overlain with thin split-thickness autograft to wounds could induce P53 expression and cell apoptosis, thereby reduce scar formation, resulting in improvement of the quality of wound healing.</p>