【Abstract】 Objective To build nano-biomimetic tissue engineered blood vessel (NBTEBV) with nanotopology by using electrospinning (ELSP) technology. Methods Cony vascular endothel ial cell(VEC) on tubiform tooting in vitro was cultured. NBTEBV was built by use of multi-row nozzle with the suspension of cony vascular smooth muscle cell (VSMC) and mimic ECM (MECM) solution. NBTEBV was cultured with bioreactor in vitro . VEC and VSMC viabil ity and prol iferation were observed with MTT; and HE staining, scanning electron microscopy(SEM) observation and biomechanical test were carried out after 24 hours of static culture and 7 days of dynamic culture. Results After 7 days of culture, the length of NBTEBV was 57 mm, the external diameter was 4 mm and the thickness of wall was 0.4 mm. The NBTEBV’s color was white and the texture was even and flexible. MTT results indicated the viabil ity of cells cultured on NBTEBV for 7 days was normal(8.9 × 106 /mg, 3.5 ×105/mg for 24 hours). SEM and HE staining indicated that the topologic character of NBTEBV was similar to that of the naturalblood vessel. The NBTEBV showed a network scaffolds structure with 100 nm thick fiber and 600 nm aperture. The HE stainingresult showed that the NBTEBV was composed of VEC and VSMC by layer. Vascular mechanical results showed that the NBTEBVultimate hydrostatic pressure was 950 mmHg, the compl iance of the NBTEBV under physio-pressure (110/70 mmHg) was 3.0%; the ultimate tensile strength of 20 mm × 5 mm tissue sl ice was 18.5 MPa. Conclusion The technology of ELSP can use VSMC and MECM scaffold simultaneously to build tissue engineered blood vessel with nanotopology mimic native blood vessel.
Objective To observe the occurrence condition of endoleak after endovascular aneurysm repair (EVAR) operation for abdominal aortic aneurysm (AAA), and to analyze the factors of the endoleak. Methods Between July 2005 and June 2013, 210 cases of AAA were treated with EVAR. Of 210 patients, 175 were male and 35 were female, aging 42-89 years (mean, 65.7 years). The patients were all proved to have infrarenal AAA by computed tomography angiography (CTA). The disease duration ranged from 1 week to 2 years (median, 11.3 weeks). The maximum diameter of the aneurysms was 44-72 mm (mean, 57.3 mm). The proximal landing zone was longer than 1.5 cm. CTA was performed routinely at 2 months after operation to detect the endoleak of contrast agent. If endoleak was found, CTA was performed again at 6 months. If obvious endoleak still existed, digital subtraction angiography (DSA) would be performed to clarify the character and the degree of the endoleak, and EVAR should be done if necessary. Results Endoleak occurred in 31 cases (14.8%) during operation, including 11 cases of type I endoleak (8 cases of type IA and 3 cases of type IB), 18 cases of type II endoleak, and 2 cases of type III endoleak (type IIIB). The patients were followed up 2-8 months (mean, 3.1 months). At 2 months after operation, contrast agent endoleak was found in the remnant aneurysm cavity of 12 cases (5.7%). At 6 months after eperation, contrast agent endoleak was found in 10 cases (4.8%) by CTA. In 8 patients receiving DSA, there were 4 cases of type I endoleak (3 cases of type IA and 1 case of type IB), 3 cases of type II endoleak, and 1 case of type III (type IIIB) endoleak. In 5 patients having type I and type III endoleak, collateral movement of stent graft was observed in different degree; after increased stent graft was implanted, the endoleak disappeared after 2-4 months. The patients having type II endoleak were not given special treatment, endoleak still existed at 2 months after reexamination of CTA, but the maximum diameter of AAA had no enlargement. Conclusion The collateral movement of stent graft is a very important factor to cause type I and type III endoleak in the patients of AAA after EVAR, and endoleak can be plugged by EVAR again.
Objective To investigate the efficacy of autologous bone marrow mononuclear cells transplantation in treating lower l imb thromboangiitis obl iterans (TAO). Methods From January 2005 to November 2008, 25 patients (27 l imbs) with lower l imb TAO were treated. There were 24 males (26 l imbs) and 1 female (1 l imb), aging 16-44 years (33 years on average). Fifteen left l imbs and 12 right l imbs were involved. The median duration of disease was 2 years (from 3 months to9 years). Intermittent claudication was observed in 5 cases (5 l imbs), 16 patients (17 l imbs) had symptom of rest pain, 4 patients (5 l imbs) suffered ulcer on the distal l imbs. The results of visual analogue scale (VAS), maximum walking distance (MWD), ankle/brachial index (ABI), and transcutaneous oxygen pressure (TcPO2) before operation were (7.16 ± 1.12) points, (0.098 ± 0.043) km, 0.20 ± 0.09, and (11.78 ± 3.46) mm Hg (1 mm Hg=0.133 kPa), respectively. A total of 300 mL bone-marrow blood was extracted from the il iac bone. And then the mononuclear cells were isolated from the bone-marrow blood. All patients received cell transplantation only one time. The amount of transplantation bone marrow mononuclear cells was (1.82-29.46) × 109 (mean 13.33 × 109). Results All patients were followed up for 1 years. After 4 weeks of implantation, the results of VAS, MWD, ABI, and TcPO2 were (2.39 ± 0.51) points, (0.783 ± 0.176) km, 0.28 ± 0.16, (21.33 ± 6.57) mm Hg, respectively, showing significant difference compared with preoperative results (P lt; 0.05). The VAS, MWD, ABI, and TcPO2 increased to (2.44 ± 0.67) points, (1.199 ± 0.304) km, 0.37 ± 0.09, (27.90 ± 5.23) mm Hg after 1 year of implantation, showing significant differences compared with preoperative results (P lt; 0.05). One ulcer healed well and the improvement was obtained in other 3 cases after 4 weeks of implantation (80%). Four ulcers healed well after 1 year of implantation (80%). After 1 year of implantation, angiography revealed 37.04% affected limbs had a satisfactory neovascularization. The angiographic levels were grade 0 in 5 cases, grade 1 in 12 cases, grade 2 in 4 cases, and grade 3 in 6 cases. Conclusion Autologous bone marrow mononuclear cells transplantation could be a simple, safe, effective method to treat TAO.
Objective To investigate the etiology, diagnosis, revascularization of upper l imb ischemia and the compl ications. Methods From March 2003 to February 2008, 72 cases of upper l imb ischemia were treated. There were 44males and 28 females, aged 19-90 years old (median 63 years old). The duration of the disease was 1 hour to 2 years. All cases had symptoms of l imb ischemia such as paleness, coldness, paralysis. According to individual condition, 72 patients accepted revascularizations including thromboembolectomy, reconstruction after traumatic injuries, pseudoaneurysm excision and angioplasty, balloon dilatation and stent implant, arterial repair, patch, vascular prosthesis or vein bypass/transplantation, and l igation or coarctation of fistula. Results Sixty patients (83.3%) recovered well after operation. Re-occlusion following thromboemboletomy was found in 6 patients (8.3%). And there were 4 patients (5.6%) with l imbs disturbance and muscles contracture and 2 patients (2.8%) with compartment syndrome in this series. The affected l imb had to be amputated in 2 patients (2.8%). And 1 patient (1.4%) died of cerebral hemorrhage because of anticoagulation 3 days after operation. All patients were followed up 1-6 years (mean 52 months) after operation. Four patients recurred and got improved after retreatments. The others got a good result with normal skin color and temperature, restoration of the radial and ulnar pulses, normal saturation of blood oxygen of finger ti p (gt; 90%) and patent blood flow of affected arteries was shown by color Doppler ultrasound. Conclusion The study indicates that identifying the etiology of upper l imb ischemia before operation and active revascularizations consistent with different causes are the key to treat the upper l imb ischemia.
Objective To observe the adhesion and prol iferation of late endothel ial progenitor cells (EPCs) planted on nanoporous PLLA scaffold in vitro and to provide a new approach that optimizes tissue engineered material. Methods Male and female New Zealand rabbits (weight 2.5-3.0 kg) were used. Isolated late EPCs from rabbit peri pheral blood were cultured. Electrostatic spinning technique was adopted to prepare misal igned nanofibers, al igned nanofibers and super-al igned nanofibers, and low temperature plasma technique was appl ied to prepare misal igned membrane, al igned membrane and super-al igned membrane. After being divided into group A (cells only), B (misal igned membrane), C (normal membrane), D (al igned membrane) and E (super-al igned membrane), the primary late EPCs (1 × 105/mL) werecultured on scaffolds and MTT method was used to detect cell prol iferation abil ity at 3, 5, 7, 9, 11, 13, 15 and 17 days afterculture. After being divided into group A (misal igned membrane), B (normal membrane), C (al igned membrane) and D (superal igned membrane), precipitation method was appl ied to detect cell adhesion rate at 4, 12 and 24 hours after compound culture, and the morphologic changes of cells were observed at 4, 24 and 72 hours after compound culture. Results Fiber diameters in nanofibrous PLLA scaffolds were 300-400 nm, with a porosity rate of above 90%. At 3, 5, 7, 9, 11, 13, 15 and 17 days after culture, A value of each group was increased with time and the cells in each group grew well, showing there was no significant difference between group A and group B at each time point (P gt; 0.05 ); during the period of 7-15 days after culture, the difference between groups C, D and E and groups A and B was significant (P lt; 0.05). At 4 hours after compound culture, the adhesion rate of group A was superior to that of groups B, C and D (P lt; 0.05); at 12 and 24 hours after compound culture, the adhesion rate of groups B, C and D was remarkably higher than that of group A (P lt; 0.05); significant difference was noted in each group between the time point of 4 hours and the time point of 12 and 24 hours after compound culture (P lt; 0.05), but no significant difference between 12 hours and 24 hours was detected (P gt; 0.05). Morphology observation demonstrated that cells grew well on the scaffolds, the cells in groups A and B grew sporadically and disorderly, while the cells in groups C and D attached and al igned along fiber and prol iferated, with an excretion of ECM. Group D was better at maintaining cell morphology. Conclusion Al igned and superal igned nanofibers of PLLA scaffold can promote the adhesion and prol iferation of seed cells on the scaffold and maintain good cell morphology, which is an appropriate candidate scaffold material for blood vessel tissue engineering. Late EPCs is an ideal cell source for blood vessel tissue engineering.
【Abstract】 Objective To design a novel small-cal iber vascular graft using a decellularized allogeneic vascularscaffold pre-loaded with bFGF. Methods The decellularized canine common carotid were obtained by a detergent-enzymatic procedure, then the scaffolds were covalently l inked with heparin and pre-loaded with bFGF, the amount of binding bFGF and releasing curve were assayed by ELISA. Canine BMSCs expanded in vitro were seed on the scaffolds to observe the effects of binding bFGF on prol iferation. Both bFGF pre-loaded and non-pre-loaded decellularized grafts were implanted in canines as carotid artery interposition for 8 weeks, the patency was examined by digital subtraction angiography and histological method. Results Histology and electron microscopic examination of the decellularized scaffolds showed that cellular components were removed completely and that the extracellular matrix structure remained intact. The amount of binding bFGF positively related to the concentration of bFGF. There was a significant difference in the amount of binding bFGF between two different scaffoldsthroughout all bFGF concentrations(P lt; 0.05), and up to 100 ng/mL, the local and sustained release of bFGF from the heparin treated scaffolds were assayed up to 20 days. Additionally, MTT test showed the bFGF-preloaded scaffolds significantly enhanced the prol iferation of seeded BMSCs in vitro compared with non-bFGF-preloaded scaffolds at 3 days after seeding and thereafter(P lt; 0.01). Furthermore, in vivo canine experiments revealed that all 8 bFGF-pre-loaded scaffolds remained patent after 8 weeks of implantation, and host cell l ined the lumen and populated the wall. Only 1 non-bFGF-pre-loaded scaffold was patent, and the other 7 grafts were occluded because of thrombsus formation. Conclusion This study provides a new strategy to develop a small diameter vascular graft with excellent biocompatibil ity and high patency rate.