Expression And Clinical Significance Of Transforming Growth Factorβ1 In Fibrous Capsule Around Expanders

Objectives: To explore the expression and clinical significance of transforming growth factor-β1(TGF-β1) in fibrous capsule around expanders, to identify the cause of fibroblast outside fibrous capsule, to find the way to control fibrous capsule's formation, and to improve the achievement ratio of rebuilding skin soft tissue or organ after dilatation.Methods1. Clinical data:We enrolled 30 patients who visited our hospital with the skin dilating symptoms over the past 2007. Every one received skin soft tissue dilation with one or more dilation implement .Of all the patients, there were 16 males, 14 females, and their age from 17 to 33( mean age 25).2 GroupsThe experiment was designed as self-contrast. The materials in the experiment group was drawn from the fibrous capsule of dilating bag, while the control group was drawn from the adjacent undertissue of the stripping lacune when the spreader implanted during one phase of operation dilation. 3 Expander implant and injection Under the local anesthesia, all cases were through operation. After striped the embedding lacune, the soft tissue dilation implement was implanted. On the 8th day after operation, water injection was executed,then repeated every 2-5 days. The volume of affusion was up to the force of the skin flap, not exceeding the limit of skin piece of blood vessel finger pressure. Water injection stopped when reaching 1.5 times of fixed capacities.4 MaterialsControl group: Under local anesthesia state, the materials (1cm*1cm) were drawn from subcutaneous tissue around expandor at implanting period and were fixed in neutral glutaraldehyde after washed in PBS. The paraffin sections were used for HE staining, Masson stainingand immunohistoche–mistry staining. The examples (0.1cm*0.1cm*0.3cm) of subcutaneous tissue were obtained and fixed in neutral formalin for transmission electron microscope.Experimental group: Under local anesthesia state, the materials (1cm*1cm) were drawn from subcutaneous tissue around expandor after implanting period and were fixed in neutral glutaraldehyde after washed in PBS. The paraffin sections were used for HE staining, Masson staining and immunohistochemistry. The examples (0.1cm*0.1cm*0.3cm) of subcutaneous tissue were obtained and fixed in neutral formalin for transmission electron microscope.5 Observation index (1) HE staining sections and Masson staining sections were observed under optical microscope to compare the contents of collagen fibers in control group and experimental group. Immunohistochemistry were observed under optical microscope to compare the contents of TGF-β1 in fibrous capsule. (2) The quantity of fibroblast was observed under transmission electron microscope to compare the difference of collagen secreted by fibroblast between two groups.Results1 Optical microscopy1.1 HE stainingOptical microscope: (1) Experimental group: massive fibroblasts and newborn thin-walled blood capillary; lots of mid-naive fibroblasts and naive fibroblast with big cell body, ecphyma on both ends and blue kytoplasm. Control group: amount of fat cells, mature fibroblasts occasionally, sporadic blood capillarys and neutrophilic granulocytes. The significant characteristic is that the contents of immature fibroblast in the experimental group were much more than that in control group.1.2 Masson stainingObservation in the optical microscope: Experimental group: green color of full-thickness fibrous capsule, sporadic fibroblast with long fusiform shape and sporadic endotheliocyte like spindle cell. Control group: thickness gray color around expandor,less fibroblast, black nuclea, orbicular-ovate, lining up puffly. 1.3 Immunohistochemistry stainingExperimental group: The positive expression of TGF-β1, distributed in endochylema and extracellular matrix of fibroblast, was large and deep. Control group: The positive expression of TGF-β1, distributed in fibroblast around interstitial vascellum, was weak. The immunohistochemistry stainings of all 30 cases were positive (high expression 25, low expreesion 5), compared with control group (p<0.01).2 Transmission electron microscope observation.Compared with control group, there were more distended rough endoplasmic reticulums with less degranulation, more integrity crista mitochondriales, more conspicuous microfil -aments,more normal Golgi complexes and free ribosomes in experimental group.Conclusion(1) The positive expression of TGF-β1 in experimental group was more than that in control group, with significant difference (p<0.01), which proves that there is close relation between TGF-β1 and formation of fibrous capsule and verifies that TGF-β1 is important cause of cicatricial tissue. (2) The overexpression of TGF-β1 in fibroblasts indicates that the excessive collagen secretion of fibroblasts can promote the formation of fibrous capsule. All our findings can provide experimental base for clinical application of TGF-β1 to control thickness and contraction of fibrous capsule and can offer an optimized skin soft tissue dilatation to improve therapeutic effect.