[Experimental study of tissue-engineered skin loaded with keratinocyte growth factor nanocapsules for skin defect].

OBJECTIVE: To study the effect of tissue-engineered skin loaded with keratinocyte growth factor (KGF) nanocapsules for skin defect on athymic mice. METHODS: The acellular dermal matrix (ADM) loaded with KGF-ADM was constructed by means of phacoemulsification solvent evaporation and low temperature drying. The human epidermal stem cells and fibroblasts were captured and identified, then cultivated on the surface of the KGF-ADM. The cell growth was observed. The tissue-engineered skin without KGF was used as sham group. The autogenous skin graft was used as control group. 2 and 6 weeks after the skin was transplanted to the back of athymic mice, the contraction and histological healing of the transplanted skins were observed respectively. Then the immunofluorescence examination with anti-human K10-FITC and beta1-integrin-Cy3 were applied to detect the origin, growth and differentiation of epidermal and dermal cells in tissue-engineered skin. RESULTS: The epidermal stem cells grew well and attached tightly on KGF-ADM. There were small round stem cells and polygonal terminally-differentiated cells, which appeared a partly cloning growth and a tendency of merging. The tissue-engineered skin with KGF nanocapsules gained better result in repairing the skin defects as compared with the blank group and the control group 2 and 6 weeks after transplantation. The regenerative skin cells could connect and mix closely with the athymic mouse skin cells on the border of skin defect. Meanwhile, the regenerative skin existed some contraction. The histological observation with HE staining showed that the regenerative skin possessed intact epidermis with several cell layers and normal keratose stratum, among which there were still some beta1-integrin (+) cells which represented epidermal stem cells or transient amplifying cells when they were tested by immunofluorescence after 6 weeks of transplantation. CONCLUSIONS: The tissue-engineered skin loaded with KGF nanocapsules had a better result in repairing athymic mice skin defects than common tissue-engineered skin without KGF nanocapsules or skin auto-graft.

A comparative study on two kinds of surgical procedures of penile corpora cavernosa augmentation.

OBJECTIVE: Penile augmentation surgery is still a controversial issue because of the uncertain indication, the possibility of severe complications and a variety of surgical techniques. The purpose of this study is to provide two surgical procedures of penile corpora cavernosa augmentation and to investigate its effect by implanting autogenous saphenous vein grafts or expanded polytetrafluoroethylene (ePTFE) vessel patches. METHODS: Between January 2001 and December 2005, 20 patients underwent surgeries in which bilateral longitudinal incisions were placed on the tunica albuginea and the penile corpora cavernosa were extended by means of implantation of saphenous grafts or PTFE artificial vessel patches. The patients included in this study presented either with congenital idiopathic micropenis or normal penile length and perimeter (dysmorphophobia). Before the operation, the penile length and perimeter in the flaccid and erectile states were as follows: flaccid length 2.5-7.5 cm and flaccid perimeter 3.0-7.5 cm; erectile length 4.9-10.5 cm and erectile perimeter 4.5-10.0 cm. RESULTS: Immediately after surgery, the penile corpus circumferential measurements (on table), showed remarkable increases which were 1.0-2.3 cm and 1.5-3.0 cm in the flaccid and erectile states, respectively; then, at 12 months to 5 years' follow-up, these girth gains had reduced by 0.5-1 cm in some cases. All cases in the two groups obtained satisfactory surgical results with satisfactory erection and no serious complications, such as infection and fistula. In 20 cases, 17 married cases resumed regular and satisfactory sexual activities 1 month after the operation without any functional limitation. CONCLUSION: The two kinds of surgical procedures for augmenting penile corpora cavernosa were proved to be effective and reliable, with few complications. Both saphenous grafts and ePTFE artificial vessel patches are excellent materials for reconstructing the tunica albuginea. These augmenting phalloplasties can not only be used for patients with micropenis, but also applied to satisfy the cosmetic and functional requests of patients with normal penile length and perimeter. However, the long-term outcomes of these surgical procedures need a further, detailed follow-up study.