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ABSTRACT: Tendon adhesions are one of the most concerning complications after surgical repair of flexor tendon injury. Extracellular signal-regulated kinase (ERK) 2 plays crucial roles in fibroblast proliferation and collagen expression which contributes to the formation of tendon adhesions after flexor tendon surgery. Using a chicken model, we have examined the effects of a small interfering RNA (siRNA) targeting ERK2 delivered by a lentiviral system on tendon adhesion formation with an adhesion scoring system, histological assessment, and biomechanical evaluation. It was found that ERK2 siRNA effectively suppressed the increase of fibroblasts and the formation of tendon adhesions (p < 0.05 compared with the control group). Moreover, no statistically significant reduction in breaking force was detected between the ERK2 siRNA group and the control group. These results show that the lentiviral-mediated siRNA system is effective in preventing tendon adhesion formation but not to tendon healing, and may be used for tendon repair after confirmation and improvement by future detailed studies.
International Journal of Molecular Sciences 01/2013; 14(2):4361-71. · 2.60 Impact Factor
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ABSTRACT: The hierarchical architecture and complex biologic functions of native sheath make its biomimetic substitute a daunting challenge. In this study, a biomimetic bilayer sheath membrane consisting of hyaluronic acid-loaded poly(ε-caprolactone) (HA/PCL) fibrous membrane as the inner layer and PCL fibrous membrane as the outer layer was fabricated by a combination of sequential and microgel electrospinning technologies. This material was characterized by mechanical testing and analysis of morphology, surface wettability, and drug release. Results of an in vitro drug release study showed sustained release. The outer layer had fewer cells proliferating on its surface compared to tissue culture plates or the inner layer. In a chicken model, peritendinous adhesions were reduced and tendon gliding were improved by the application of this sheath membrane. Taken together, our results demonstrate that such a biomimetic bilayer sheath can release HA sustainably as well as promoting tendon gliding and preventing adhesion.
Biomacromolecules 10/2012; · 5.48 Impact Factor
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ABSTRACT: The objective of the present investigation was to characterize the antibacterial and osteogenic properties of plasma sprayed
silver-containing hydroxyapatite (HA/Ag) coating in vitro. HA/Ag coating was deposited via vacuum plasma spraying. The concentration of silver ions released from HA/Ag coating, the
efficacy of the HA/Ag coating against bacterial biofilm development, the effect of the HA/Ag coating on early adhesion and
ossification of osteoblast cells in vitro was measured. The silver ion concentration released from the HA/Ag coating was between the minimum inhibitory concentration
to bacteria and the cytotoxic concentration. Bacterial biofilm inhibition studies indicated an antibacterial activity on the
HA/Ag coating surface when compared with hydroxyapatite (HA) coating alone. Moreover, it was demonstrated that osteoblast
cell adhesion and mineralization occurred on the HA/Ag coating surface during the testing period. We conclude that the vacuum
plasma sprayed HA/Ag coating possesses good antibacterial capability and osteogenic properties in vitro and represents a promising candidate for coating orthopedic implants.
Chinese Science Bulletin 04/2012; 54(23):4438-4445. · 1.32 Impact Factor
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ABSTRACT: To discuss the feasibility of repairing soft tissue defects of lower extremity with a distally based posterior tibial artery perforator cross-bridge flap or a distally based peroneal artery perforator cross-bridge flap.
Between August 2007 and February 2010, 15 patients with soft tissue defect of the legs or feet were treated. There were 14 males and 1 female with a mean age of 33.9 years (range, 25-48 years). The injury causes included traffic accident in 8 cases, crush injury by machine in 4 cases, and crush injury by heavy weights in 3 cases. There was a scar (22 cm x 8 cm at size) left on the ankle after the skin graft in 1 patient (after 35 months of traffic accident). And in the other 14 patients, the defect locations were the ankle in 1 case, the upper part of the lower leg in 1 case, and the lower part of the lower leg in 12 cases; the defect sizes ranged from 8 cm x 6 cm to 26 cm x 15 cm; the mean interval from injury to admission was 14.8 days (range, 4-28 days). Defects were repaired with distally based posterior tibial artery perforator cross-bridge flaps in 9 cases and distally based peroneal artery perforator cross-bridge flaps in 6 cases, and the flap sizes ranged from 10 cm x 8 cm to 28 cm x 17 cm. The donor sites were sutured directly, but a split-thickness skin graft was used in the middle part. The pedicles of all flaps were cut at 5-6 weeks postoperatively.
Distal mild congestion and partial necrosis at the edge of the skin flap occurred in 2 cases and were cured after dressing change, and the other flaps survived. After cutting the pedicles, all flaps survived, and wounds of recipient sites healed by first intention. Incisions of the donor sites healed by first intention, and skin graft survived. Fifteen patients were followed up 7-35 months with an average of 19.5 months. The color and texture of the flaps were similar to these of the recipient site. According to American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot score system, the mean score was 87.3 (range, 81-92).
A distally based posterior tibial artery perforator cross-bridge flap or a distally based peroneal artery perforator cross-bridge flap is an optimal alternative for the reconstruction of the serious tissue defect of contralateral leg or foot because of no microvascular anastomosis necessary, low vascular crisis risk, and high survival rate.
Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery 07/2011; 25(7):826-9.
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ABSTRACT: To investigate the antibacterial and osteogenic capabilities in vivo of hydroxyapatite (HA)/silver (Ag) coating.
HA/Ag coating (Ag quality percentage was 3%) and HA coating were deposited to external fixator Schanz screws. The tibial fracture model was established in right hindlimb of 18 adult male Beagle dogs (weighing 15-20 kg). The tibia was stabilized with an external fixator and 2 Schanz screws of HA coating at proximal tibia (control group, n = 18) and HA/Ag coating at distal tibia (experimental group, n = 18), and every screw incision was infected with Staphylococcus aureus. Infection in screw holes and the changes of bone-screw interface were observed by wound grading and X-ray films.
In control group, wounds infection became worse with time (chi2 = 13.492, P = 0.001), while in experimental group, no obvious change was observed chi2X = 0.208, P = 0.901). The wound grading of experimental group was significantly better than that of the control group at 1, 2, and 3 weeks (P < 0.05). Laser scanning confocal microscope showed that there was bacterial adhesion on the surface of screws in 2 groups, viable bacteria mainly in control group and non-viable bacteria mainly in experimental group. The scanning electron microscope (SEM) observation results of the fractured sclerous tissue section showed that an obvious transparent boundary between screw and bone in control group, but no obvious boundary in experimental group. The osseointegration ratios were 76.23% +/- 15.54% in control group and 93.42% +/- 5.53% in experimental group, showing significant difference ( t = 8.843, P = 0.000). The SEM observation showed that HA/Ag coating integrated with new bone and the surface of implant was filled with new bone in experimental group; obvious interspace was seen between the HA coating and new bone in control group.
HA/Ag coating has good antibacterial and osteogenic capabilities, so it can take effects in preventing infection in screw holes and loosening of implants.
Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery 06/2011; 25(6):668-72.
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ABSTRACT: To discuss the effect of sciatic nerve repair at different angles on the neural regeneration in rats.
Seventy-two male Sprague Dawley rats were randomly divided into groups A, B, C, and D with 18 rats in each group. The right sciatic nerve was transected at 30, 45, 60, and 90 degrees in groups A, B, C, and D, respectively, and then was repaired. The morphologic assessment of nerve regeneration was performed by gross observation, the wet weight recovery rate of gastrocnemius, histological and ultrastructural observations at 1, 2, and 3 months after operation.
Three months later, the wet weight recovery rate of gastrocnemius, motor nerve conduction velocity and action potential of sciatic nerve, axonal diameter, medullary sheath thickness, and medullated nerve fiber counting in groups A and B were significantly better than those in groups C and D (P < 0.01); but no significant difference was found between group A and group B (P > 0.05), and between group C and group D (P > 0.05).
End-to-end neurorrhaphy at 30-45 degrees can effectively promote the sciatic nerve regeneration in rats.
Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery 05/2011; 25(5):587-90.
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ABSTRACT: Interleukin (IL)-1β plays an important role in the pathogenesis of osteoarthritis and catabolic processes in articular cartilage. Growing evidence suggests that ERK1/2 activation is involved in IL-1β-mediated matrix metalloproteinase (MMP) 3, MMP13, type II collagen and aggrecan expression in chondrocytes. To investigate the respective effects and the relationship of ERK1 and ERK2, knockdown of ERK1 and/or ERK2 was performed in human chondrocytes using specific small interfering RNAs (siRNAs), and the cells were treated with IL-1β (10 ng/ml) for 24 h. Uninfected chondrocytes treated with IL-1β (10 ng/ml) were used as a positive control. Other cells cultured without IL-1β or siRNA treatment were used as a negative control. The mRNA levels of MMP3, MMP13, type II collagen and aggrecan were evaluated by quantitative real-time PCR. The protein levels of MMP3 and MMP13 in the culture medium were examined by ELISA. The protein levels of type II collagen, aggrecan, ERK1/2 and phospho-ERK1/2 were evaluated by western blotting. The results indicate that IL-1β enhances MMP3 and MMP13 expression and inhibits type II collagen and aggrecan expression. Activation of the MAPK/ERK pathway was observed. Knockdown of ERK1 or ERK2 significantly reversed these effects to similar degree. Combined knockdown of ERK1 and ERK2 displayed synergistic effects. ERK1 and phospho-ERK1 or ERK2 and phospho-ERK2 were inhibited by knockdown of ERK1 or ERK2, respectively. No compensatory effect by up-regulation of the opposite isoform was observed. The combined knockdown suppressed ERK1/2 and phospho-ERK1/2. The data suggest that although inhibition of both ERK1 and ERK2 is more effective, inhibition of either ERK isoform may be sufficient and could be used for novel therapies or as drug targets for pharmacological intervention in cartilage breakdown in osteoarthritis.
International Journal of Molecular Medicine 02/2011; 27(4):583-9. · 1.98 Impact Factor
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ABSTRACT: The MAPK/ERK pathway is involved in IL-1β-induced cyclooxygenase (COX-2) expression and prostaglandin E2 (PGE2) production; two factors that play important roles in OA pathogenesis. In the present study, we find that IL-1β induced COX-2 expression and PGE2 production in human chondrocytes via a process that required the activation of the MAPK/ERK pathway. To evaluate the respective roles and relationship of ERK1 and ERK2 on IL-1β induced COX-2 expression and PGE2 production, small interfering RNA was used to knockdown ERK1, ERK2 or both in human chondrocytes. COX-2 expression and PGE2 production were significantly suppressed to a similar degree by the silencing of ERK1 or ERK2 alone. Moreover, the combined knockdown displayed a synergistic effect. Simultaneously, Western blotting indicated that the knockdown of ERK1 or ERK2 down regulated phospho-ERK1 and ERK1 or phospho-ERK2 and ERK2 levels, respectively. No significant compensatory mechanism through the upregulation of the other phospho-ERK and ERK isoform was observed. The combined silencing suppressed both phospho-ERK1/2 and ERK1/2. In conclusion, each ERK isoform similarly influenced IL-1β-mediated COX-2 expression and PGE2 production in human chondrocytes, and ERK1 and ERK2 displayed synergistic effects. Although, inhibition of both ERK1 and ERK2 would be a more effective, each ERK isoform may sufficiently regulate these effects in human chondrocytes. ERK1 or ERK2 may be potential therapeutic target for the inflammatory process of OA.
Biochemical and Biophysical Research Communications 09/2010; 402(1):23-9. · 2.48 Impact Factor
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ABSTRACT: A cross-leg or cross-bridge free flap is one of the choices for the reconstruction of serious leg soft tissue defects. Here, we report on six cases of leg and foot reconstruction with a distally based extended peroneal artery septocutaneous perforator cross-bridge flap without microvascular anastomoses. The vascular pedicle includes the peroneal artery, its perforator branch, and concomitant veins. The total pedicle length ranges from 10 to 14 cm, and the size ranges from 18 x 8 to 21 x 10 cm. All flaps survived completely without complications. Compared with a cross-leg or cross-bridge free flap, a distally based extended peroneal artery septocutaneous perforator cross-bridge flap without microvascular anastomoses does not require the use of some instruments or techniques for microsurgery, leading to a shorter operation duration and a lower risk of thrombosis in the vessel because microvascular anastomosis is not required.
Journal of Reconstructive Microsurgery 03/2010; 26(4):243-9. · 1.43 Impact Factor
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ABSTRACT: Transforming growth factor-beta1 and fibroblast growth factor-2 play very important roles in fibroblast proliferation and collagen expression. These processes lead to the formation of joint adhesions through the SMAD and MAPK pathways, in which extracellular signal-regulated kinase (ERK)2 is considered to be crucial. Based on these theories, we examined the effects of a lentivirus-mediated small interfering RNA (siRNA) targeting ERK2 on the suppression of joint adhesion formation in vivo. The effects were assessed in vivo from different aspects including the adhesion score, histology and joint contracture angle. We found that the adhesions in the ERK2 siRNA group became soft and weak, and were easily stretched. Accordingly, the flexion contracture angles in the ERK2 siRNA group were also reduced (P<0.05 compared with the control group). The animals appeared healthy, with no signs of impaired wound healing. In conclusion, local delivery of a lentivirus-mediated siRNA targeting ERK2 can ameliorate joint adhesion formation effectively and safely.
Biochemical and Biophysical Research Communications 12/2009; 391(1):795-9. · 2.48 Impact Factor
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ABSTRACT: A cross-leg or cross-bridge free flap is frequently used for the reconstruction of leg defects in cases with no suitable recipient vessels in the vicinity of the defect. Here we report eight cases of leg reconstruction with a distally based posterior tibial artery cross-bridge flap without microvascular anastomosis technology. A distally based posterior tibial artery flap was elevated and used to reconstruct contralateral leg defects. A skin incision was made near the recipient wound to create a skin bridge, and a subcutaneous tunnel was made between the skin incision and the recipient wound for the vascular pedicle to pass over. All flaps survived completely without complications, except for a case with minor erosion in the donor site. Compared with a cross-leg or cross-bridge free flap, a distally based posterior tibial artery cross-bridge flap is reliable and versatile, leading to shorter operation duration and a lower risk of thrombosis in the vessel because microvascular anastomosis is not required.
Journal of Reconstructive Microsurgery 11/2009; 26(3):159-64. · 1.43 Impact Factor
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ABSTRACT: To investigate the operative technique and clinical results of repairing the soft tissue defects of knee with antegrade extended peroneal artery perforator flap.
From October 2007 to January 2008, 3 patients (2 men and 1 woman) with the soft tissue defects of knee were treated, with the ages of 18, 31 and 42 years, respectively. The first case sustained femur and pelvis fractures and soft tissue defect over his right popliteal fossa, which were treated with open reduction and internal fixation (ORIF) and debridement of knee joint 2 weeks ago. The second case was necrosis of skin 3 weeks after ORIF for fracture of tibial plateau. The third case suffered from open fracture of tibial plateau and soft tissue defect, which were treated with external fixation and debridement 3 weeks ago. The defect sizes were 16 cm x 9 cm, 11 cm x 6 cm and 14 cm x 7 cm. The flap was raised by dividing the peroneal artery and veins distally and elevating them proximally, which covered for the defects of knee. The flaps were designed with the size of 18 cm x 10 cm, 12 cm 7 cm and 15 cm x 8 cm. The pure vascular pedicle of the flap was 10 cm to 17 cm in length, including the peroneal vessels and one or two perforator branches. The donor site is covered by a split thickness skin graft.
All flaps survived after surgery. The donor sites healed by first intention and the skin grafts survived. After following up for 6, 8 and 11 months, the appearance and function of the flaps were all satisfactory. Based on the modified HSS knee performance system, post-operative knee functional outcomes of three patients were excellent.
The antegrade extended peroneal artery perforator flap supplied by a pure vascular pedicle can be a good alternative for reconstruction of knee. The flap, with a long and thin pure vascular pedicle, could provide good texture and contour matching the recipient area.
Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery 04/2009; 23(3):303-5.
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ABSTRACT: To prepare silver-containing hydroxyapatite coating (hydroxyapatite/Ag, HA/Ag) and investigate its antibacterial property and biocompatibility in vitro.
Vacuum plasma spraying technique was adopted to prepare HA/Ag coating on titanium alloy substrate (3% Ag). After incubating the HA/Ag and the HA coating under staphylococcus aureus and pseudomonas aeruginosa suspensions of 2% tryptic soy broth (TBS) medium for 2, 4 and 7 days, respectively, the biofilm on the coatings was examined by confocal laser scanning microscope, and the bacterial density and viable bacterial percentage of bacterial biofilm were calculated. Meanwhile, the micro-morphology of bacterial biofilm was observed by SEM, the cytotoxicity was detected via MTT and the biocompatibility of biofilm was evaluated by acute haemolysis test.
Compared with HA coating, the bacterial biofilm's thickness on the surface of HA/Ag coating witnessed no significant difference at 2 days after culture (P > 0.05), but decreased obviously at 4 and 7 days after culture (P < 0.01). The bacterial density of the biofilm increased with time, but there was no significant difference between two coatings (P > 0.05) at 2, and 7 days after culture. The viable bacterial percentage of the biofilms on the surface of HA/Ag coating decreased obviously compared with that of HA coating at 2, 4 and 7 days after culture (P < 0.01). The MTT notified the cytotoxic grade of both coatings was zero. The acute haemolysis assay showed that the hemolytic rate of HA/Ag and HA coating was 0.19% and 0.12%, respectively.
With good biocompatibility, significant antibacterial property against staphylococcus aureus and pseudomonas aeruginosa, no obvious cytotoxicity and no erythrocyte destruction, the vacuum plasma sprayed HA/Ag coating is a promising candidate for the surface of orthopedic metal implants to improve their osseointegration and antibacterial property.
Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery 02/2009; 23(2):226-30.
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ABSTRACT: Silver-containing hydroxyapatite (HA) coatings have been prepared on titanium substrate by vacuum plasma spraying (VPS) method and anti-bacterial properties of the coatings were examined. Three types of bacteria stains, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, were employed in this test. The results showed that the silver-containing HA coatings exhibited significant anti-bacterial effects against the three bacteria with anti-bacterial ratios higher than 95%. The release of silver ions in the physiological environment ensured excellent anti-bacterial properties of the silver-containing HA coatings. International standard ISO 10993-12 was adopted for cytotoxicity evaluation using fibroblast cell line L929, and it was found that the cytotoxicity for the coatings ranked 0 that showed no cytotoxicity for the coatings. Hemolysis test was processed according to ASTM F 756 standard with anti-coagulated rabbit blood, and the hemolysis ratios of the coatings were below 0.4%, indicating of non-hemolysis for the coatings.
Journal of Materials Science Materials in Medicine 12/2008; 19(12):3603-9. · 2.32 Impact Factor
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ABSTRACT: To investigate the method and effect of compound grafting of vascularized fibular head and flaps to repair complicated lateral malleolus defects.
From July 2000 to April 2006, 6 patients with lateral malleolus bone defect underwent the repairing treatment. There were 5 males and 1 female, aged 9-47 years. The causes of injuries was traffic accident in 4 cases and crash in 2 cases. And 5 cases were in the left side and 1 in right side. The bone defect ranged 3.5-8.5 cm in size and the skin defect ranged 14 cm x 4 cm-18 cm x 7 cm in size. The time from injury to surgery ranged from 15 to 30 days. The complicated lateral malleolus defects were repaired by transplanting the fibular head pedicled with the lateral inferior genicular artery 5-10 cm, and the peroneal perforator flaps or latissimus dorsi flaps 16 cm x 5 cm-20 cm x 8 cm. The raw surfaces of donor site were inflated and packaged with intermediate split thickness skin graft.
One flap with 1 cm distal edge dry necrosis healed after change of dressing and others all survived. The free skin grafts survived and the incision healed by the first intention. All the cases were followed up for 4 to 15 months, and all patients achieved the bony healing within 8-16 weeks and the transplanted fibular head grew well. The shape of reconstructed lateral ankles was similar to the normal one and the ankle mortise moved well. The texture of flaps was soft without diagnosis and abrasion. According to Baird-Jackson criterion, the results were excellent in 3 cases, good in 2 cases and fair in 1 case and the excellent and good rate was 83.3%.
The fibular head pedicled with the lateral inferior genicular artery has good blood supply and the reconstructed lateral malleolus is similar to the normal. The peroneal perforator flaps and latissimus dorsi flaps have adequate blood supply and big dermatomic area. So this operation is an effective method to repair lateral malleolus defect.
Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery 12/2008; 22(11):1288-91.
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ABSTRACT: To investigate the operative techniques and clinical results of repairing the soft tissue defects of forearm and hand with free peroneal perforator-based sural neurofasciocutaneous flap.
From May 2006 to January 2007, 6 patients including 5 males and 1 female were treated. Their ages ranged from 22 years to 51 years. They were injured by motor vehicle accidents (2 cases), or crushed by machines (4 cases), with skin defect of hand in 1 case, skin defect of hand associated with tendon injuries and metacarpal fractures in 2 cases, skin defect of forearm in 2 cases, and forearm skin defects with fractures of radius and ulna in 1 case. The areas of soft tissue defect ranged from 16 cm x 7 cm to 24 cm x 10 cm. The debridement and the primary treatment to tendons or bones were performed on emergency. And free flaps were transplanted when the wound areas were stable at 4 to 7 days after the emergent treatment. During the operation, the flaps were designed along the axis of the sural nerve nutrient vessels according to the shape and size of the soft tissue defects, with the peroneal perforator above the lateral malleolus as the pedicle and along with a part of the peroneal artery for vascular anastomosis. Then the flaps were harvested and transferred to the recipient sites with the peroneal varley anastomosed to the radial (or ulnar) artery and the peroneal veins to one of the radial (or ulnar) veins and the cephalic vein, respectively. The flap size ranged from 18 cm x 8 cm to 25 cm x 12 cm. The donor areas were closed by skin grafts.
The 5 flaps survived after the surgery. Partial inadequate venous return and distal superficial necrosis happened in only 1 case, which also got secondary healing by changing dressing and anti-infective therapy. The donor sites reached primary healing completely. The followed-up in all the patients for 6 to 13 months revealed that the appearance and function of the flaps were all satisfactory, and no influence on ambulation of donor site was found.
Peroneal perforator-based sural neurofasciocutaneous flap has the advantages of favourable appearance, constant vascular pedicle, reliable blood supply, large size of elevation and minor influence on the donor site. And the free transfer of this flap is an ideal procedure to repair the large soft tissue defects of forearm and hand.
Zhongguo xiu fu chong jian wai ke za zhi = Zhongguo xiufu chongjian waike zazhi = Chinese journal of reparative and reconstructive surgery 06/2008; 22(6):724-7.
