Clinical Application of Long-Pulsed 800-Nm Diode Laser Depilation Technology on Microtia Reconstruction in 965 Patients.

BACKGROUND: The issue of hair growth on reconstructed ears has been a matter of concern for both patients and surgeons, despite the notable progress made in microtia reconstruction technology in recent times. OBJECTIVE: This study aims to present the practical implementation of long-pulsed 800-nm diode laser depilation technology in the field of auricular reconstruction. Furthermore, it seeks to establish a comprehensive and standardized protocol for utilizing lasers in the reconstruction of microtia ears. METHODS: A total of 965 patients (comprising 1021 ears) diagnosed with congenital microtia underwent treatment using 800-nm long-pulsed diode laser depilation. The participants received 1-3 treatment sessions with intervals of 25-30 days. To assess the effectiveness of the treatment, two independent observers compared photographs and measured the reduction in terminal hair count before and after the final session. Clinical outcomes were evaluated using VAS questionnaires, and any adverse events were diligently recorded. RESULTS: The findings indicated that the utilization of the long-pulsed 800-nm diode laser was both safe and efficient in achieving hair removal during microtia ear reconstruction. As additional sessions were conducted, pain scores demonstrated a decline, while adverse reactions remained minimal. LIMITATIONS: This is a retrospective single-institution study. CONCLUSION: The application of a long-pulsed 800-nm diode laser has been proved to be a safe and effective method for removing hair during the process of microtia ear reconstruction, involving the use of a tissue expander and autologous costal cartilage. To achieve satisfactory results in hair removal, it was found necessary to repeat the shots procedure two to three times. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Aberrant Notch signalling contributes to hypertrophic scar formation by modulating the phenotype of keratinocytes.

Hypertrophic scar (HS) is characterized by fibroblast hyperproliferation and excessive matrix deposition. Aberrant keratinocyte differentiation and their abnormal cytokine secretion are said to contribute to HS by activating fibroblasts. However, the signalling pathway causing the aberrant keratinocytes in HS has remained unidentified thus far. Given that Notch signalling is crucial in initiating keratinocyte differentiation, we hypothesized that Notch signalling contributes to HS by modulating the phenotype of keratinocytes. We found that Notch1, Notch intracellular domain, Jagged1 and Hes-1 were overexpressed in the epidermis of patients with HS. Supernatants from recombinant-Jagged1-treated keratinocyte cultures could accelerate dermal fibroblast proliferation and collagen production. Furthermore, Jagged1 induced keratinocyte differentiation and upregulated the expression of fibrotic factors, including transforming growth factors ß1 and ß2 , insulin-like growth factor-1, connective tissue growth factor, vascular endothelial growth factor and epidermal growth factor, while DAPT (a Notch inhibitor) significantly suppressed these processes. In a rabbit ear model of HS, local application of DAPT downregulated the production of fibrotic factors in keratinocytes, together with ameliorated scar hyperplasia. Our findings suggest that Notch signalling contributes to HS by modulating keratinocyte phenotype. These results provide new insights into the pathogenesis of HS and indicate a potential therapeutic target.

An alternative model of vascularized bone marrow transplant: partial femur transplantation.

The vascularized whole femur transplantation model is one of the commonly used vascularized bone marrow transplant models. It involves technical complexity and morbidities. To optimize this model, we took 2/3 femur as the carrier of bone marrow cells, and developed a vascularized partial femur model. Four experimental groups were carried out, namely, the syngeneic partial femur transplantation, allogeneic partial femur transplantation with or without cyclosporine A, and allogeneic whole femur transplantation with cyclosporine A. The results showed that the partial femur model was technically simpler and shortened the operative and ischemia time compared to the whole femur model. Gross and histologic appearance confirmed the viability of femur, and its bone marrow inside the bone could also maintain normal morphologically at 60-day posttransplant. Besides, donor multilineage chimerism could be continuously detected in immunosuppressed allogeneic partial femur recipients at 1-, 2-, 3-, 4-, and 8-week posttransplant, and it showed no significant differences when compared with whole femur transplantation. Meanwhile, long-term engraftment of donor-origin cells was also confirmed in recipients' bone marrow, lymph nodes, and spleen, but not in thymus. Therefore, the vascularized partial femur can serve as a continuous resource of bone morrow cells and may provide a useful tool for the study of immune tolerance in vascularized composite allotransplantation.

The effects of vasonatrin peptide on random pattern skin flap survival.

BACKGROUND: A lot of methods have been intensively investigated to improve random skin flap survival. Decreasing inflammation and alleviating tissue injury have been reported to be effective in improving survival ratio. Vasonatrin peptide (VNP) is a chimera of atrial natriuretic peptide (ANP) and C-type natriuretic peptide (CNP). The current study demonstrates that VNP possesses the venodilating actions of CNP, the natriuretic actions of ANP, and the unique arterial vasodilating actions not associated with either ANP or CNP. However, its effects on skin flap survival have not been previously reported. METHODS: Sprague-Dawley rats, weighing 220 to 260 g, were randomly divided into 2 groups, namely, the VNP-treated group and the control group. Rectangular random dorsal skin flaps measuring 3 × 9 cm including the panniculus carnosus were elevated, then the flaps were sutured into their original places. In the VNP group, 0.1 mg/kg of VNP was administered intravenously (IV) after surgery and then daily for 3 days. In the control group, 1 mL/kg of saline was administered IV after surgery and then daily for 3 days. To observe the effects of VNP, blood perfusion, histopathological examination, the inflammatory mediators (tumor necrosis factor α, interleukin 1ß, and interferon γ), and biochemical analysis (malondialdehyde, glutathione, and myeloperoxidase) were detected and the flap viability was evaluated 7 days after surgery by measuring necrotic flap area and total flap area. RESULTS: The viability measurements showed the percentage of flap survival was increased in the VNP-treated group (76.53% ± 6.36%) as compared with the control group (61.12% ± 4.92%) (P < 0.05), and the histological and biochemical assays corroborated the data. The blood perfusion of flaps in the VNP-treated group was higher than the control group (P < 0.05). The inflammatory mediators (tumor necrosis factor α, interleukin 1ß, and interferon γ) were significantly lower in the VNP-treated group than the control group (P < 0.05). CONCLUSIONS: This study found that VNP, which could elevate the tissue blood perfusion and mitigate the tissue damage and inflammatory reaction, is associated with a higher percentage of survival random pattern skin flap area.

Staged corrective surgery for complex adolescent kyphoscoliosis caused by back scalding during the childhood period.

INTRODUCTION: Adolescent scar contracture kyphoscoliosis is a very rare disease. METHODS AND RESULTS: Here, we present the case of a 21-year-old man who was scalded due to ebullient water when he was 10 years old. Moreover, kyphoscoliosis was found when he was 12 years old and developed rapidly. Thereafter, no management was proposed before his consultation at our center. On examination, kyphoscoliosis was detected in thoracolumbar, the trunk deviated to the right on standing view, extensive contractured scar presented on the right side of the back, abdomen, chest wall, hip, right thighs and armpit anterior, especially in the right flank. A one-stage correction was deemed too risky, we therefore released contractured scar during the first stage with the defect of soft tissue protected by vacuum sealing drainage and then performed skeletal traction with halo and bilateral femoral pins. A reasonable correction was achieved without any neurological deficits 1 month after traction. Next, a second-stage operation was taken to translate a free anterolateral thigh myocutaneous flap to overlay the extensive defect of soft tissue. 1.5 months later, a third posterior segmental pedicle screw instrumented fusion with Smith-Peterson osteotomy between T9 and L2 was performed. Postoperative recovery was uneventful and as there were no complications, he was discharged 10 days after the third surgery. At 2-year follow-up the patient's outcome is excellent with balance and correction of the deformity. CONCLUSION: Based this grand round case and relevant literature, we discuss the different options for the treatment of adolescent scar contracture scoliosis.

Effect of combined OX40Ig and CTLA4Ig gene local transfer on allograft rejection and the underlying mechanisms.

BACKGROUND: OX40Ig and CTLA4Ig fusion proteins have been suggested to induce immune tolerance and prevent rejection in allografts. The present study aims to investigate and compare the effects of ex vivo combined OX40Ig and CTLA4Ig lentivirus-mediated gene transfer on the long-term survival of the graft, as well as potential underlying mechanisms. METHODS: We ex vivo transferred Brown Norway rats' superficial groin free flap with lentivirus vectors expressing OX40Ig or CTLA4Ig, or OX40Ig and CTLA4Ig combined, and transplanted the free flaps to Lewis rats. Short-course rapamycin was administered after transfection and transplantation. RT-PCR and Western blot were employed to evaluate expression of OX40Ig and CTLA4Ig. We assessed the survival time of the grafts and the degree of acute graft rejection after indicated treatment. Mixed lymphocyte reaction, flow cytometry, and ELISA were also used to evaluate systemic immune reactions. RESULTS: Ex vivo transfer of OX40Ig or CTLA4Ig lentivirus vectors led to local expression of corresponding mRNA and proteins in the donor flap without affecting other organs of the recipient. The graft survival time was significantly expanded and rejection was markedly attenuated after transfection. Mixed lymphocyte reaction, flow cytometry (CD4(+) and CD8(+) T lymphocyte proportions), and serum ELISA analysis (IL-2, IFN-γ, IL-4, and IL-10) also showed decreased immune response following transfection. Combined OX40Ig and CTLA4Ig transfer exerted superior effect on improving graft survival and preventing graft rejection, inhibiting the immune response and decreasing the production of proinflammatory cytokines, compared with singular transfer of either OX40Ig or CTLA4Ig. CONCLUSION: Combined ex vivo transfer of OX40Ig and CTLA4Ig lentivirus vectors provided superior benefits on long-term survival and restoration of the graft through inhibiting immune response and decreasing the production of proinflammatory cytokines.

[Study on the effect of CD4+CD25+ regulatory T cell adoptive transfusion on humoral immune function in rat composite tissue allotransplantation model].

OBJECTIVE: To approach the effect of the donor antigenic specificity CD4+CD25+ regulatory T cell (Treg) on cellular immune tolerance function in rat composite tissue allotransplantation (CTA). METHODS: Use the method of immunomagnetic beads to separate CD4+CD25+ Treg, (1 x 10(6))CD4+CD25+ Treg was transfused to rat CTA model. Collected peripheral blood 30 days after operation, and used nylon wool column to separate B cell and T cell. With the stimulation of IgM, detected B cell proliferation and the level of IgG and IgA in serum. Observed the effect of CD4+CD25+ Treg on B cell and T cell function and the survival of allotransplants, and analyzed the data by statistics. RESULTS: The purity of separated CD4+CD25+ Treg was 95.6%. The CPM of T cell of normal control group, topical intervention group, systemic intervention group and non-intervention group were (2436 +/- 358), (2273 +/- 136), (2338 +/- 228) and (3749 +/- 245). The CPM of B cells of normal control group, topical intervention group, systemic intervention group and non-intervention group were (2418 +/- 348), (2252 +/- 127), (2315 +/- 218) and (3720 +/- 224), there was a significant difference in these groups (P < 0.01). The serum level of IgG and IgA of topical intervention group and systemic intervention group were (12.56 +/- 1.30), (2.38 +/- 0.21), (13.48 +/- 1.23) and (2.86 +/- 0.24) g/L, and of normal control group was (12.35 +/- 1.28), (2.36 +/- 0.12) g/L, had no significant difference (P > 0.05). But Treg of non-intervention group was (16.58 +/- 1.12), (3.75 +/- 0.37) g/L, there was a significant difference in the non-intervention group and the three above groups (P < 0.01). The survival time of CTA in intervention of local and systemic groups were (97 +/- 13) and (63 +/- 10) d, which were significant longer than the non-intervention group [(22 +/- 8) d, P < 0.01]. CONCLUSIONS: Donor antigen specific CD4+CD25+ Treg has significantly inhibited B cell and T cell function. It can induce immune tolerance and extend the survival time of CTA; as well local application is better than systemic.

Effect of camptothecin on collagen synthesis in fibroblasts from patients with keloid.

Keloids are distinguished by substantial deposition of collagen in the dermis, resulting in an imbalanced production and aggregation of extra cellular matrix. This study was undertaken to evaluate the effects of the topoisomerase I inhibitor camptothecin (CPT) on collagen synthesis in the activated dermal fibroblasts from healthy donors and patients with keloid. The fibroblasts were cultured in the presence or absence of CPT. Cellular toxicity assay was determined by MTT analysis. The expression of type I collagen and type III collagen was studied both at the transcriptional and post-transcriptional levels, using conventional quantitative real-time reverse transcription PCR and Western blotting. Results showed that there was predominantly a clear and dose-dependent decrease in the synthesis of collagen 1, not collagen 3, in keloid fibroblasts without significantly cellular toxicity. The CPT had an activity on the regulation of the ratio of type I/III collagen in the metabolism of keloid fibroblasts by inhibiting the secretion of type I collagen. The data suggest that the inhibitory effect of CPT, a topoisomerase I inhibitor, on collagen synthesis may be an effective treatment for limiting fibrosis in keloid patients.

Wedge-shaped excision and modified vertical mattress suture fully buried in a multilayered and tensioned wound closure.

BACKGROUND: A successful deep multilayered wound suture should provide a firm tension-relieving closure, good wound-edge eversion, hemostasis, and minimal intradermal extraneous materials. However, this is not always achieved with a single standard technique. The authors describe their modification of a wound closure method that can rapidly and reliably achieve these results. METHODS: A wedge-shaped excision was adopted to obtain a trapezoid pattern transect, after which a modified fully buried vertical mattress suture technique was used to close the wound. These techniques were compared with the standard excision and suture techniques used for the same patient at different times after surgery. RESULTS: The wedge-shaped excision can facilitate good wound-edge eversion, and the modified fully buried vertical mattress suture can provide firm tension relief and optimal apposition. Compared with conventional excision and suture techniques, the described techniques brought about a better outcome in terms of hypertrophic scar prevention. CONCLUSION: The described modified technique seems to be more efficient than conventional procedures used to prevent hypertrophic scar formation.

[Blocking of Notch signaling decreased scar formation in rabbit ear hypertrophic scar model].

OBJECTIVE: To investigate the effects of Notch signaling on scars in a rabbit ear model of hypertrophic scarring. METHODS: The hypertrophic scar of rabbits' ears was reproduced. The left rabbit's ear wounds as the N-[N-(3,5-difluorophenacetyl-L-alanyl)]-(S)-phenylglycine t-butyl ester (DAPT) treated group were treated intradermally with the gamma-secretase inhibitor DAPT to inhibit the activation of Notch at 1, 3, 7 and 14 day time points. The right ears as the control group were treated with normal saline at the same time points. Experimental and control wounds were harvested on days 14, 21, 28 and 35 post wounding, and then examined histologically to quantify hypertrophic index and fibroblasts. The expression of epidermal differentiation markers-keratin 14 (K14), keratin 19 (K19), Involucrin and Notch downstream molecules-P21, P63 were examined and analyzed with immunohistochemistry staining. RESULTS: Both hypertrophic index (1.93 +/- 0.32, 1.82 +/- 0.36, 1.79 +/- 0.25) and number of fibroblasts [(4.08 +/- 0.88), (3.30 +/- 0.53), (3.19 +/- 0.73) x 10(3)/mm(2)] in the DAPT treated group were significantly reduced on days 21, 28 and 35, compared with the control group [2.56 +/- 0.29, 2.61 +/- 0.30, 2.58 +/- 0.39, and (5.45 +/- 0.99), (4.80 +/- 1.13), (4.43 +/- 1.17) x 10(3)/mm(2), all P < 0.01)]. The K19, K14 and P63 increased their expression in the DAPT treated group (28.6% +/- 5.7%, 53.1% +/- 4.5%, 57.0% +/- 5.8%) relative to the control group (10.1% +/- 2.8%, 30.8% +/- 4.9%, 16.5% +/- 2.2%, all P < 0.01) on day 14 post wounding, while the Involucrin and P21 decreased their expression in the DAPT treated group (12.3% +/- 1.9%, 11.0% +/- 1.7%) relative to the control group (29.3% +/- 4.6%, 44.3% +/- 3.5%, both P < 0.01). CONCLUSION: Inactivation of Notch signaling will inhibit scar epidermis to over-differentiation, and thereby inhibit proliferation of hypertrophic scars in the rabbit ears.

[Adenovirus-mediated CTLA4 immunoglobulin based conditioning for non-myeloablative allogeneic hematopoietic cell transplantation to induce tolerance to hind limb allografts in rats].

OBJECTIVE: To investigate a non-toxic AdCTLA4-Ig-based protocol for non-myeloablative allogeneic hematopoietic cell transplantation to induce donor-specific tolerance to hind limb allografts in rats. METHODS: Fully mismatched, 4 to 8 week old Brown Norway (RT1(n)) and Lewis (RT1(1)) rats were used as cell/organ donors and recipients, respectively. Recipients were treated with AdCTLA4-Ig (5 x 10(9) PFU, day -30, 0, 30), standard immunosuppressive therapy (MP: 10 mg x kg(-1) x d(-1), MMF: 20 mg x kg(-1) x d(-1), RAPA: 0.2 mg x kg(-1) x d(-1);day -33 - 100), soon after total body irradiation (3 Gy, day -30) and donor bone marrow (100 x 10(6), day -30) transplantation (BMT). Thirty days after BMT, chimeric animals received hind limb transplantations. And 100 days after hind limb transplantations, immunosuppressive therapy was changed for low-dosed CsA (8 mg x kg(-1) x d(-1), day 100-), until the allografts were rejected. RESULTS: In Group C, hematopoietic chimerism was (38.8 +/- 10.6)% at day 0, and was stable (29.3 +/- 11.9)% at 330 days post-BMT. There was no graft versus host disease in both Group C and Group D. When the standard immunosuppressive therapy was stopped and changed for low-dosed CsA, chimeric recipients (Lewis, RT1(1)) permanently accepted (> 200 days) donor specific (Brown Norway, RT1(n)) hind limb allografts in Group C, yet rapidly rejected in Group A (8 +/- 2) d, Group B (18 +/- 3) d and in Group C (20 +/- 2) d. Lymphocytes of graft tolerant animals' demonstrated hyporesponsiveness in mixed lymphocyte cultures in a donor-specific manner in Group C. Tolerant graft histology showed no obliterative arteriopathy or chronic rejection. CONCLUSION: The AdCTLA4-Ig based conditioning regimen with donor BMT produce stable mixed chimerism and induce donor-specific tolerance to hind limb allografts.

Inhibition of vascular endothelial growth factor expression in keloid fibroblasts by vector-mediated vascular endothelial growth factor shRNA: a therapeutic potential strategy for keloid.

Vascular endothelial growth factor (VEGF) plays important roles in the regulation of angiogenesis and inflammation in both pathological and physiological wound repair. Several strategies have been developed for keloid therapy; however, a universally effective treatment has not been explored to date. In this study, three potential short interfering RNA (siRNA) sequences for the VEGF gene were cloned into expression plasmids and transfected into keloid fibroblasts. PGC-VEGF shRNA 2 (short hairpin RNA 2) plasmid significantly inhibited VEGF expression determined by real-time polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), and fibroblasts growth was also significantly by (methyl thiazolyl tetrazolium) MTT assay and apoptosis detection, whereas the control transfection showed no obviously effects. Plasminogen activator inhibitor-1 (PAI-1) expression in pGC-VEGF shRNA2 group was also obviously downregulated when compared to the pGC-VEGF shRNA negative control and mock group. These results suggest that modulation of VEGF production by vector-based RNAi in keloid fibroblasts may be a therapeutic potential strategy for keloid.

Infantile hemangioma is originated from placental trophoblast, fact or fiction?

Infantile hemangiomas are common, benign tumors, distinctive for their perinatal presentation, rapid growth and subsequent involution. Hemangiomas can pose serious concerns to the cosmetic and psychosocial development of the afflicted child, but none of the current therapeutic modalities is ideal to date, partly because the origin of the pathogenic ECs in infantile hemangioma is unknown. Many clues and evidences suggest a link between infantile hemangiomas and the maternal placental trophoblasts. Shared expression of distinct endothelial markers in hemangioma and placental tissues raises a possibility that infantile hemangioma is originated from placental trophoblast. Moreover, the findings of a very high similarity between the transcriptomes of placenta and hemangioma provide strong support for this theory. Furthermore, epidemiologic and clinical evidences accumulated in recent years also suggest the placental trophoblast as the cell of origin for infantile hemangioma. These findings imply a unique relationship between hemangioma and the placental trophoblast and suggest a hypothesis that infantile hemangioma is originated from placental trophoblast. The hypothesis could provide new understanding of these vascular tumors of childhood and may become the most promising research fields for the etiology of infantile hemangiomas. Further study of the precise mechanisms for the placental trophoblast originated hemangiomas will produce new preventive strategies and therapeutic avenues, possibly immunologic treatment, to the very difficult problem.

Proliferation hemangiomas formation through dual mechanism of vascular endothelial growth factor mediated endothelial progenitor cells proliferation and mobilization through matrix metalloproteinases 9.

Infantile hemangioma is the most common tumor of infancy and the mechanism leading to proliferation hemangiomas formation is poorly understood and currently no successful treatment modality exists. We hypothesize that EPCs formed during proliferation hemangiomas, as the result of vascular endothelial growth factor (VEGF) stimulation through MMP9, play the major role in the control of cell proliferation and capillary-like vessels production. Accepting the hypothesis to be correct, a therapy that inhibits EPC mobilization and proliferation can be used to prevent the proliferation hemangiomas formation. Current therapies are only partially effective and safe because they could not eliminate all the relative factors of proliferation hemangiomas formation at all, such as: EPCs in the peripheral blood, and at the same time inducing death (apoptosis and necrosis) of other normal cells. A more efficient prevention of proliferation hemangiomas could be achieved using specific drugs or biologic methods that inhibit EPC mobilization and proliferation. Therapy based on gene therapy, capable to specifically inhibit VEGF and MMP9 expression in gene level, can be possibly effective.

Possibilities and potential roles of estrogen in the pathogenesis of proliferation hemangiomas formation.

Hemangiomas, often categorized as angiogenic diseases, are the most common tumors of infancy, the life span of which is generally divided into proliferating phase, involuting phase, and involuted phase. Despite their high prevalence, the mechanism leading to proliferation hemangiomas formation is poorly understood and the best approach to their management remains controversial. None of the current therapeutic modalities is ideal, partly because the pathogenesis of hemangioma and the mechanism of its proliferation are far from clear. Many clues reveal that estrogen has an important role in developing the vascular system, experimental and clinical evidences accumulated in recent years also suggest the potential for estrogen to influence neovascularization. Based on those, we hypothesize that estrogen play a potential role in the development of hemangiomas, mainly by regulating some key angiogenic factors, including MMP-9, EPCs, VEGF, NO, etc. Accepting the hypothesis to be correct, a therapy that identify estrogen as a potential target for the design of new, more specific treatments can be used to prevent the proliferation hemangiomas formation. The hypothesis may lead a new direction in the study of mechanisms for proliferation hemangiomas formation, and further study of the precise mechanisms for estrogen-induced hemangiomas will produce effective antiestrogens and estrogen receptor antagonists as new medication for the very difficult problem.

Silibinin Induced Human Glioblastoma Cell Apoptosis Concomitant with Autophagy through Simultaneous Inhibition of mTOR and YAP.

Silibinin, also known as silybin, is the major flavonolignan isolated from Silybum marianum. Although previous reports demonstrated that silibinin exhibits significant tumor suppressor activities in various cancers by promoting cell apoptosis, it was also shown to trigger autophagy to counteract apoptosis induced by exogenous stresses in several types of cells. However, there is no report to address the role of silibinin induced autophagy in human A172 and SR glioblastoma cells. Our study showed that silibinin treatment not only inhibited the metabolic activities of glioblastoma cells but also promoted their apoptosis through the regulation of caspase 3 and PARP-1 in concentration- and time-dependent manners. Meanwhile, silibinin induced autophagy through upregulation of microtubule-associated protein a light chain 3- (LC3-) II. And autophagy inhibition with chloroquine, a lysosomotropic agent, significantly enhanced silibinin induced glioblastoma cell apoptosis. Moreover, silibinin dose-dependently downregulated the phosphorylation levels of mTOR at Ser-2448, p70S6K at Thr-389, and 4E-BP1 at Thr-37/46. Furthermore, the expression of YAP, the downstream effector of Hippo signal pathway, was also suppressed by silibinin. These results suggested that silibinin induced glioblastoma cell apoptosis concomitant with autophagy which might be due to simultaneous inhibition of mTOR and YAP and silibinin induced autophagy exerted a protective role against cell apoptosis in both A172 and SR cells.

Enhancing skin flap survival by a cell-permeable wild-type survivin.

Skin grafts, including skin flaps, are widely used in plastic and reconstructive surgery to cover wounds and tissue defects resulting from mechanic or burn injury. Ischemic necrosis is the main complication in skin graft surgery due to inefficient revascularization. Though the surgical delay procedure has been proved to be the only effective technique to prevent skin flap ischemic necrosis by mechanism of inducing adaption to hypoxia, but it is time consuming, costly, and having high risk of infection due to repeated surgery. Recent research demonstrated that, in addition to protecting cells against apoptosis, the expression of survivin correlates with intratumoral microvessel density in several different types of tumors and survivin could upregulate several proangiogenic factors, including VEGF, Egr-1 and Siah-1. Moreover, Survivin DeltaEx3, one of the survivin alternative splice variants, is necessary for activating the small GTPase Rac1 during endothelial tube formation and required for in vivo endothelial cell invasion. Therefore, we postulate that intracellular delivery of survivin or Survivin DeltaEx3 by fusion with protein transduction domain would enhance skin flap survival through accelerating revascularization by both inhibiting the apoptosis of microvascular endothelial cells and promoting skin flap angiogenesis. If the hypothesis was proved to be practical, the fusion proteins would be widely used in plastic and reconstructive surgery to prevent skin flap from ischemic necrosis in the future.

[Effects of mouse NIH3T3 cells transfected with VEGF gene on neovascularization of ischemic flaps].

OBJECTIVE: To investigate the feasibility of applying NIH3T3 cells transfected by VEGF gene to the treatment of ischemic random skin flaps. METHODS: Plasmid PcDNA3.1(-)/VEGF(165) containing VEGF gene was transduced into the mouse NIH3T3 cells by liposome. Immunohistochemistry was used to detect the expression of VEGF protein of mouse NIH/3T3 cells in vitro. The NIH3T3 cells were stained with CM-DiI before the transplantation. Thirty mice were randomized into 3 groups: Groups A, B and C, and were respectively injected with NIH/3T3 cells transfected with PcDNA3.1(-)/VEGF(165) plasmid, NIH/3T3 cells and medium only. On the 4th day after the injection, random dorsal skin flaps with an area of 4.0 cm x 1.5 cm were established. The survival, neovascularization and blood flow recovery of the flaps were detected. RESULTS: VEGF-transduced NIH3T3 cells expressed VEGF highly in vitro and in vivo. The results showed that flap survival rate in group A (95.1% +/- 3.1%) was significantly higher than those in group B (37.4% +/- 6.3%) and group C (26.2% +/- 5.6%). The capillary density and the blood perfusion of the flaps in group A were significantly higher than those in other two groups. CONCLUSIONS: VEGF-transfected NIH3T3 cells can improve ischemic flap neovascularization and extend survival areas.

Targeting of angiopoietin 2-small interfering RNA plasmid/chitosan magnetic nanoparticles in a mouse model of malignant melanoma in vivo.

The aim of the present study was to observe the in vivo targeting characteristic of angiopoietin 2-small interfering RNA (Ang2-siRNA) plasmid/chitosan magnetic nanoparticles in an established nude mouse model of malignant melanoma (MM) under an external magnetic field. The nude mouse MM model was first established, then divided into 3 groups, including the control group, the non-targeting group and the target group, the control group was given normal saline and the non-targeting and targeting groups were administrated particles through the tail vein; the non-targeting group was not under external magnetic field and the control group and the targeting group were under external magnetic field for 60 min. The mice were then sacrificed and the tumor tissues were stained with hematoxylin and eosin and Prussian blue in order to verify the particle distributions in the tumor tissues. The control group exhibited negative Prussian blue staining in the tumor tissues, the non-targeting group demonstrated weakly positive Prussian blue staining in tumor tissues and the targeting group revealed strongly positive Prussian blue staining in tumor tissues. Ang2-siRNA plasmid vector/chitosan magnetic nanoparticles directly moved towards tumor tissues under the action of external magnetic field, thus it demonstrated good targeting characteristic.