혈행화 신경이식 후 신경재생에 대한 형태계측학적 연구

탁관철,안성준,김대용,이영호,Tark, Kwan-Chul,Ahn, Sung-Jun,Kim, Dae-Yong,Lee, Young-Ho 대한미세수술학회 1997 Archives of reconstructive microsurgery Vol.6 No.1

Adequate vascularization is pivotally essential for a successful nerve graft. Theoretically, the immediate vascularization will inhibit fibroblast infiltration and stimulate nerve cell regeneration. In this study, histomorphological and electrophysiological studies were performed to determine if vascularized grafts are functionally superior. In rat model, a 4cm segment of the sciatic nerve was obtained and placed as a non vascularized graft on one side, and as a vascularized graft connected to the inferior gluteal vessels on the opposite side. To determine the compound action potential of the gastrocnemius muscle, electromyography was done after 2, 3 and 4 months. Histomorphologically, the distribution of myelinated nerve fibers and Schwann cell were evaluated after toluidine blue staining, The following resutls were obtained: 1. The electrophysiological studies showed no difference between the nonvascularized and vascularized grafts. 2. Two and three months after grafting, myelinated nerve fibers were more abundant in the vascularized proximal, middle and distal areas in all nerve fibers of varying diameters. 3. In the post-nonvascularized graft 2-month group, a few myelinated nerve fibers were present in the proximal and middle areas, but none distally. In the post-vascularized graft 2 month group, myelinated nerve fibers ranging $2-8{\mu}m$ were present in all three areas. 4. In the post-nonvascularized graft 3 month group, a few myelinated nerve fibers ranging in $2-6{\mu}m$ were present in all three areas, but in the post-vascularized graft 3 month group, many myelinated nerve fibers ranging in $2-10{\mu}m$ were present in all three areas. 5. In the post-graft 4-month group, more myelinated nerve fibers were present in all three areas of the vascularized grafts. However, nerve fibers of less than $2{\mu}m$ in diameter were more abundant in the non vascularized grafts. 6. Schwann cells were more abundant in the proximal, middle and distal areas of the post-vascularized 2, 3 and 4-month grafts. Based on these findings, the immediate restoration of circulation in vascularized nerve grafts allows for the increased number of surviving Schwann cells, rapid healing of the axon and myelin sheath changes which occur during Wallerian degeneration, and thus is able to stimulate a morphologically optimal regeneration.

Surface Coating of Polytetrafluoroethylene with Extracellular Matrix and Anti-CD34 Antibodies Facilitates Endothelialization and Inhibits Platelet Adhesion Under Sheer Stress

Lei Chen,Haipeng He,Mian Wang,Xiaoxi Li,Henghui Yin 한국조직공학과 재생의학회 2017 조직공학과 재생의학 Vol.14 No.4

Expanded polytetrafluoroethylene (ePTFE) polymers do not support endothelialization because of nonconductive characteristics towards cellular attachment. Inner surface modification of the grafts can improve endothelialization and increase the long-term patency rate of the ePTFE vascular grafts. Here we reported a method of inner-surface modification of ePTFE vascular graft with extracellular matrix (ECM) and CD34 monoclonal antibodies (CD34 mAb) to stimulate the adhesion and proliferation of circulating endothelial progenitor cells on ePTFE graft to enhance graft endothelialization. The inner surface of ECM-coated ePTFE grafts were linked with CD34 mAb in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) solution and the physicochemical properties, surface morphology, biocompatibility, and hemocompatibility of the grafts were studied. The hydrophilicity of CD34 mAb-coated graft inner surface was significantly improved. Fourier transform infrared spectroscopy analysis confirmed ECM and CD34 mAb cross-linking in the ePTFE vascular grafts with our method. Scanning electron microscopy analysis showed protein layer covering uniformly on the inner surface of the modified grafts. The cell-counting kit-8 (CCK-8) assay confirmed that the modified graft has no obvious cytotoxicity. The modified graft showed a low hemolytic rate (0.9%) in the direct contact hemolysis test, suggesting the modification improved hemocompatibility of biopolymers. The modification also decreased adhesion of platelets, while significantly increased the adhesion of endothelial cells on the grafts. We conclude that our method enables ePTFE polymers modification with ECM and CD34 mAb, facilitates endothelialization, and inhibits platelet adhesion on the grafts, thus may increase the long-term patency rate of the prosthetic bypass grafts.

Enhancement of in vivo endothelialization of tissue-engineered vascular grafts by granulocyte colony-stimulating factor

Cho, Seung-Woo,Lim, Joung Eun,Chu, Hun Su,Hyun, Hye-Jin,Choi, Cha Yong,Hwang, Ki-Chul,Yoo, Kyung Jong,Kim, Dong-Ik,Kim, Byung-Soo Wiley Publishers 2006 Journal of Biomedical Materials Research Part A Vol. No.

<P>Successful reconstruction of large-diameter blood vessel in humans has been demonstrated using the tissue engineering technique, but improvement in patency of small-diameter bioartificial vascular graft remains a great challenge. This study reports that granulocyte colony-stimulating factor (G-CSF) can enhance in vivo endothelialization of tissue-engineered vascular grafts, which could be used to improve patency of small-diameter vascular graft. Vascular grafts were tissue engineered with decellularized canine abdominal aortas and canine autologous bone marrow–derived cells. Prior to cell seeding onto decellularized graft matrices, bone marrow–derived cells were induced to differentiate into endothelial cells and smooth muscle cells. The cell-seeded vascular grafts were implanted into the abdominal aortas of bone marrow donor dogs. Before and after graft implantation, G-CSF was administered subcutaneously to the dogs (n = 3). The grafts implanted into the dogs not receiving G-CSF were used as controls (n = 3). Eight weeks after implantation, grafts in both groups showed regeneration of vascular tissues including endothelium and smooth muscle. Importantly, endothelium formation was more extensive in the G-CSF–treated grafts than in the control grafts, as assessed with reverse transcription polymerase chain reaction, western blot, and immunohistochemistry. In addition, intimal hyperplasia was significantly reduced in the G-CSF–treated grafts compared to the control grafts. This study suggests that G-CSF administration could be applied to improve patency of small-diameter tissue-engineered vascular grafts. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res, 2006</P>

항혈전성 소구경 인조 혈관에 대한 동물 실험

나찬영 世宗醫學硏究所 2000 世宗醫學 Vol.17 No.2

Effect of Wall Structures on Mechanical Properties of Small Caliber PHBHHx Vascular Grafts

Jing Gao,Zhenzhen Huang,Huiwen Guo,Shunzhu Tian,Lu Wang,Yuling Li 한국섬유공학회 2019 Fibers and polymers Vol.20 No.11

In order to analyze the effect of vascular wall structures on static and dynamic mechanical properties of vasculargrafts, small calibre PHBHHx (Poly(3-hydroxybutyrate-co-3-hydroxhexanoate)) vascular grafts (inner diameter 6 mm) withvarious wall shapes and thicknesses were fabricated by changing electrospinning time and receiving molds. As spinning timeincreased, wall thickness of the vascular grafts increased and both circumferential tensile strength and suture retentionstrength improved significantly. When the wall thicknesses of straight grafts were about 120 μm, the great radial dynamiccompliance was exhibited, however, the tensile strength and suture retention strength of the straight tubes can’t reach therequirements of normal blood vessel grafting. With the wall thicknesses increasing above 250 μm, although thecircumferential tensile strength and suture retention strength gradually achieved the transplanting requirements, the dynamiccompliance of the straight tubes declined too sharply to adapt the blood radial shock. For corrugated grafts, the effect of wallthickness on radial dynamic compliance was little, and the radial dynamic compliance was close to that of the commercialvascular grafts. The circumferential tensile strength and suture retention strength of the corrugated grafts were also improvedto approach the commercial vessels’ performances with the wall thickness improving to about 425 μm. Elastic recovery ratesof all the prepared vascular grafts were superior to that of the commercial sample. Along with the wall thickness exceeding250 μm, the water permeabilities of both the straight and the corrugated grafts were less than 300 ml/(cm2·min).

Vascular loop graft 술식을 이용한 $Kienb\"{o}ck$씨 질환의 치료

한정수,정덕환,박보연,남기운,한현수,Han, Chung-Soo,Chung, Duke-Whan,Park, Bo-Yeon,Nam, Gi-Un,Han, Hyun-Soo 대한미세수술학회 1993 Archives of reconstructive microsurgery Vol.2 No.1

Although the etiology of $Kienb\"{o}ck's$ disease is clearly related to avascular changes in the lunate, but the actual cause leading to this vascular impairment has remained elusive. Therefore, a great many different surgical procedures have been proposed for the correction of the multiple factors leading to lunate collapse or for the treatment of the lunatomalacia. The treatment modalities includes lunate excision, intercarpal arthrodesis, lunate implant resection arthroplasty, joint levelling operation(e.g ulnar lengthening & radial shortening), pronater quadratus pedicle graft and vascular loop graft. In the period from Jan. 1981 to Dec. 1992, we performed operative treatment in 19 cases of $Kienb\"{o}ck's$ disease. Among them, 6 cases were treated with vascular loop graft. We analysed all patients who were treated with vascular loop graft after followed up of 4 year 6 months, on an average(range from 1 year to 8 year 10 months). The results analysed are as follows, 1. All cases were stage III according to Lichtman's classification. 2. Ulnar variance was -1.5(range$-2{\sim}0$), on an average. 3. The average age of patients were 37.7years old(range 31-41). 4. Postoperatively, there were considerable restoration of range of motion and complete relief of pain in all cases, but continued decrease of grip power in one case. 5. Decreased sclerosis, loss of fragmentation and new bone formation were appeared in the last follow up film, in all cases. The vascular loop graft considered as a useful method for the treatment of the $Kienb\"{o}ck's$ disease.

Enhanced Patency and Endothelialization of Small-Caliber Vascular Grafts Fabricated by Coimmobilization of Heparin and Cell-Adhesive Peptides

Choi, Won Sup,Joung, Yoon Ki,Lee, Yunki,Bae, Jin Woo,Park, Han Ki,Park, Young Hwan,Park, Jong-Chul,Park, Ki Dong American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.7

<P>The clinical utility of a small-caliber vascular graft is still limited, owing to the occlusion of graft by thrombosis and restenosis. A small-caliber vascular graft (diameter, 2.5 mm) fabricated by electrospinning with a polyurethane (PU) elastomer (Pellethane) and biofunctionalized with heparin and two cell-adhesive peptides, GRGDS and YIGSR, was developed for the purpose of preventing the thrombosis and restenosis through antithrombogenic activities and endothelialization. The vascular grafts showed slightly reduced adhesion of platelets and significantly decreased adsorption of fibrinogen. In vitro studies demonstrated that peptide treatment on a vascular graft enhanced the attachment of human umbilical vein endothelial cells (HUVECs), and the presence of heparin and peptides on the graft significantly increased the proliferation of HUVECs. In vivo implantation of heparin/peptides coimmobilized graft (PU-PEG-Hep/G+Y) and PU (control) grafts was performed using an abdominal aorta rabbit model for 60 days followed by angiographic monitoring and explanting for histological analyses. The patency was significantly higher for the modified PU grafts (71.4%) compared to the PU grafts (46.2%) at 9 weeks after implantation. The nontreated PU grafts showed higher levels of alpha-SMA expression compared to the modified grafts, and for both samples, the proximal and distal regions expressed higher levels compared to the middle region of the grafts. Moreover, immobilization of heparin and peptides and adequate porous structure were found to play important roles in endothelialization and cellular infiltration. Our results strongly encourage that the development of small-caliber vascular grafts is feasible.</P>

토끼의 협골궁을 이용한 유경골이식과 유리골이식의 비교연구

장가용,한상훈,정복성,박철규 大韓成形外科學會 1993 Archives of Plastic Surgery Vol.20 No.1

The membranous bone is new used frequently to fill the defect made during the craniofacial osteotmy. The membranous bone is resolved less than the endochondral bone after the free graft, and maintains its greater preportion when it is transfered with its vascular pedicle. It is also known that there is less resorption in the orthotopic graft than in the heterotopic graft. We have stuided the amount of resorption of the orthotopically grafted bone in the vascularized and nonvascularized model. A zygomatic arch of the rabbit was resected completely and was fixed orthotopically using a wire. The contralateral one was resected and fixed with its muscle attachment(masseter). After 8 weeks the animals were sacrificed. The volume of the grafted bone was compared. There 10±2% volume loss in the vascularized modol and 18±4% volume loss in the free graft model with a statistically significant difference(P<0.001). Histologically, in the vascularized graft, primary bony union was observed and the original architecture was preserved well and the periosteal activity way great. The free graft was also healed by bony union except in 1 case. But the architectural irregularity was more prominent in the free graft than in the vascularized graft.

혈관부착 생비골 중첩 이식술

정덕환,Chung, Duke-Whan 대한미세수술학회 1998 Archives of reconstructive microsurgery Vol.7 No.1

Free vascularized fibular is the most usuful bony donor of the long bone reconstruction in reconstructive microsurgical field. It has many benifits such as very strong strut tubular bone, very reliable vascular anatomy with large vascular diameter with long pedicle, minimal donor site morbity too. In that situations of the huge long bone defects in distal femur or proximal tibia, the defective bony shape and strength of the transplanted fibular bone is not enough if only one strut of the fibula is transfered. The bony circulation of the fibula has two ways, one from nutrient artery via peroneal artery through nutrient foramen which makes endosteal arterial network inside of the fibula, another way is periosteal network through outside encircling vascular network of the bone which distributed in muscle sleeves of the fibular diaphysis. Authors modified free vascularized fibular bone graft with transverse osteotomy is made from the anterolateral aspect of the fibular shaft just distal to entry of the nutrient artery. This produces two vascularized bone struts that may be folded pararell to each other but that remain connected by the periosteum and muscle cuff surrounding the peroneal artery and veins. The proximal strut is vascularized by both a periosteal and endosteal blood supply, whereas the distal strut is vascularized by a periosteal blood supply alone. This procedure can call "doule barrel" free vascularized fibular graft. We performed 7 cases of doule barrel fashined fibular transplantation on distal femur and proximal tibial large defects. Average bone union time takes 7 months from that procedure. There were no significant bone union time differences between both proximal and distal struts. After solid union of the transfered double barrel fibular graft, there were no stress fracture in our series. We can propose double barrel free vascualized fibular graft is usuful method in that cases with very large bone defect on large long bones especially metaphyseal defects.

무세포혈관과 자가 골수줄기세포를 이용한 조직공학적 인공혈관 제조

김동익,김병수,조승우,임정은,어현선,이민재,김종성,장인성 대한혈관외과학회 2004 Vascular Specialist International Vol.20 No.1