• Macromolecular Research
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• v.15 no.6
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• pp.553-559
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• 2007

Nanocomposite films were prepared by sol-gel synthesis from vanadium triisopropoxide with $poly((oxyethylene)_9$ methacrylate)-graft-poly(dimethyl siloxane), POEM-g-PDMS, producing in situ growth of vanadium oxide within the continuous ion-conducting POEM domains of micro phase-separated graft copolymer. The formation of vanadium oxide was confirmed by wide angle x-ray scattering (WAXS) and Fourier transform infrared (FT-IR) spectroscopy. Small angle x-ray scattering (SAXS) revealed the spatially-selective incorporation of vanadium oxide in the POEM domains. Upon the incorporation of vanadium oxide, the domain periodicity of the graft copolymer monotonously increased from 17.2 to 21.0 nm at a vanadium content 14 v%, above which it remained almost invariant. The selective interaction of vanadium oxide with POEM was further verified by differential scanning calorimetry (DSC) and FT-IR spectroscopy. The nanocomposite films exhibited excellent mechanical properties $(l0^{-5}-10^{-7}dyne/cm^2)$, mostly due to the confinement of vanadium oxide in the POEM chains as well as the interfaces created by the microphase separation of the graft copolymer.

• The Korean Journal of Health Service Management
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• v.13 no.4
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• pp.133-144
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• 2019

Objectives: To analyze the radiologic results of patients treated with bone defects treated with beta-tricalcium phostphate (β-TCP) in orthopedic surgery. Methods: Medical records of 49 patients, consisting of 24 (49.0%) men and 25 (51.0%) women were retrospectively reviewed. Graft incorporation was evaluated based on Irwin's radiologic staging. Results: The explanatory power of the total regression equation in Irwin's stage at 3 months postoperatively according to three explanatory variables, namely graft tightness, age at diagnosis, and lesion volume, was 65.6%; the explanatory power of Irwin's stage at 6 months postoperatively according to two variables, namely lesion volume and graft tightness, was 32.9%; and the explanatory power of Irwin's stage at 9 months postoperatively for two variables, namely longitudinal lesion length and graft tightness in the total regression, was 30.8%. Conclusions: Graft tightness, lesion volume, age at diagnosis, and longitudinal lesion length are the common factors affecting graft incorporation.

• Journal of the Korean Arthroscopy Society
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• v.13 no.1
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• pp.53-57
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• 2009

The pretibial cyst is a very rare complication after anterior cruciate ligament (ACL) reconstruction. It occurs whatever kind of graft choice or kind of graft fixation method at tibial side. It have been known such as graft necrosis at tibial side, extra-articular leakage of joint fluid through tibial tunnel, foreign body reaction due to breakdown of the bioabsorbable screw and incomplete incorporation of graft to bony tunnel as the cause of pretibial cyst. We experienced one case of pretibial cyst which had undergone ACL reconstruction with autogenous hamstring graft fixed with biodegradable interference screw. We report a rare case of pretibial cyst with literature review.

• Journal of the Korean Orthopaedic Association
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• v.56 no.1
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• pp.14-25
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• 2021

Several factors need to be considered for a successful anterior cruciate ligament (ACL) reconstruction, such as preoperative planning, operation technique, and postoperative rehabilitation. Graft choice, fixation, preparation method, maturation, incorporation to host bone, and graft tension should also be considered to achieve a good outcome after an ACL reconstruction. Factors to consider when selecting a graft are the graft strength, graft fixation, fixation site healing, and donor site morbidity, as well as the effects of initial strength, size, surface area, and origin of the graft on its potential for weakening during healing. There are two types of graft for an ACL reconstruction, autograft or allograft. Several autografts have been introduced, including the bone-patellar tendon-bone, hamstring tendon, and quadriceps tendon-bone. On the other hand, each has its advantages and disadvantages. The recent increased use of allografts for an ACL reconstruction is the lack of donor site morbidity, decreased surgical time, diminished postoperative pain, and good availability of source. Despite this, there are no reports suggesting that an allograft may have a better long-term outcome than an autograft. Allografts have inherent disadvantages, including a longer and less complete course of incorporation, remodeling, biomechanically inferiority to autograft, the potential risk of an immunogenic reaction and disease transmission. Higher long-term failure rates and poorer graft maturation scores were reported for allografts compared to autografts. An autograft in an ACL reconstruction should remain the gold standard, although the allograft is a reasonable alternative. If adequate length and diameter of autograft can be obtained for an ACL reconstruction, an autograft with adequate graft fixation and postoperative rehabilitation should be chosen instead of an allograft to achieve better results.

• Journal of Korean Foot and Ankle Society
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• v.9 no.2
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• pp.197-200
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• 2005

We performed lateral ankle ligament reconstructions using Achilles allograft on patients who had failed previous Brostrom repair. The bone plug is fixed with an interference screw into the calcaneus, the tendon graft is passed through a fibular tunnel, and then anchored into the talus with the biotenodesis screw. The graft is strong enough to maintain joint stability until graft incorporation and remodeling occurs. In patients with chronic failed lateral ankle instability requiring graft for ligament reconstruction, this technique allows anatomic reconstruction without the need to sacrifice autogenous peroneal tendons.

• Biomaterials and Biomechanics in Bioengineering
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• v.2 no.2
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• pp.97-109
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• 2015

A series of amphiphilic graft copolymers were synthesized by varying the number of graft chains and graft chain lengths. The polarity of the hydrophobic graft chain on the copolymers was varied their solution properties. The glass transition temperature of the copolymers was in the low-temperature region, because of the amorphous nature of poly (trimethylene carbonate) (PTMC). The surface morphology of the lyophilized colloid gel had a bundle structure, which was derived from the combination of poly(N-hydroxyethylacrylamide)( poly(HEAA)) and PTMC. The solution properties were evaluated using dynamic light scattering and fluorescence measurements. The particle size of the graft copolymers was about 30-300 nm. The graft copolymers with a higher number of repeating units attributed to the TMC (trimethylene carbonate) component and with a lower macromonomer ratio showed high thermal stability. The critical association concentration was estimated to be between $2.2{\times}10^{-3}$ and $8.9{\times}10^{-2}mg/mL$, using the pyrene-based fluorescence probe technique. These results showed that the hydrophobic chain of the graft copolymer having a long PTMC segment had a low polarity, dependent on the number of repeating units of TMC and the macromonomer composition ratio. These results demonstrated that a higher number of repeating units of TMC, with a lower macromonomer composition, was preferable for molecular encapsulation.

• Macromolecular Research
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• v.17 no.5
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• pp.301-306
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• 2009

This work has demonstrated that a novel amphiphilic poly(epichlorohydrine)-graft-polystyrene (PECH-g-PS) copolymer at 34:66 wt% was synthesized via atom transfer radical polymerization (ATRP) of styrene using PECH as a macroinitiator. The structure of the graft copolymer was characterized by nuclear magnetic resonance ($^1H$ NMR) and FTIR spectroscopy, demonstrating that the "grafting from" method using ATRP was successful. The self-assembled graft copolymer was used as a template film for the in-situ growth of silver nanoparticles from $AgCF_3SO_3$ precursor under UV irradiation. The in situ formation of silver nanoparticles with 6-8 nm in average size in the solid state template film was confirmed by transmission electron microscopy (TEM), UV-visible spectroscopy and wide angle X-ray scattering (WAXS). Differential scanning calorimetry (DSC) also displayed the selective incorporation and the in situ formation of silver nanoparticles within the hydrophilic PECH domains, probably due to stronger interaction of the silvers with the ether oxygens of PECH backbone than that with hydrophobic PS side chains.

• Archives of Plastic Surgery
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• v.36 no.4
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• pp.432-436
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• 2009

Purpose: Negative pressure therapy has been used in various conditions to promote wound healing. It has also been used to secure a skin graft by improving microcirculation and improving tight adhesion between the graft and the recipient bed. To reduce post burn scar contracture and improve aesthetical result, many types of dermal substitutes have been invented and used widely. The goal of this study was evaluate usefulness of the VAC (Kinetic concepts Inc., San Antonio, TX) in improving the take rate and time to incorporation of Integra$^{(R)}$ in reconstruction of burn scar contracture. Methods: A retrospective study was performed from October, 2006 to December, 2008. The VAC was utilized for 11 patients. The average patient's age was 19.7 years (range 5 - 27) and average surface area was $785cm^2$ (range 24 - 1600). The burn scars were excised deep into normal subcutaneous tissue to achieve complete release of the scar, Integra$^{(R)}$ was sutured in place with skin staple와 Steri - strip$^{(R)}$. Then slit incisions were made on silicone sheet only with No.11 blade for effective drainage. The VAC was used as a bolster dressing over Integra$^{(R)}$. Negative - Pressure ranging from 100 to 125 mm Hg was applied to black polyurethane foam sponge trimmed to the appropriate wound size. An occlusive seal over the black polyurethane foam sponge was maintained by a combination of the occlusive dressing, OP - site$^{(R)}$. The VAC dressing changes were performed every 3 or 4 days until adequate incorporation was obtained. The neodermis appeared slightly yellow to orange color. When the Integra$^{(R)}$ deemed clinically incorporated, The VAC was removed and take was estimated with visual inspection. Very thin STSG(0.006 ~ 0.008 inches) was performed after silicone sheet removal. Result: The mean time for clinically assessed incorporation of Integra$^{(R)}$ was 10.00 days (range 9 - 12). The mean dressing change was 3.5 times until take was obtained. In All patients, Integra$^{(R)}$ had successful incorporation in tissue without serious complications. Conclusion: Integra$^{(R)}$ in combination with Vacuum - Assisted Closure(VAC) may be incorporated earlier than conventional dressing method.

• The Journal of the Korean bone and joint tumor society
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• v.2 no.1
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• pp.18-26
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• 1996

We investigated the effect of deep-freezed, boiled and autoclaved autogenous long bone graft on the incorporation of the radial diaphyseal reconstruction in 30 rabbits by radiogram and histology for 8 weeks. Immediate histologic changes of 1cm of resected long bone treated by deep freezing, boiling and autoclaving in each 2 rabbits were also observed as control. Resected, boiled ($95^{\circ}C$ for 5 min.) and reimplanted bone was compared with resected, autoclaved ($131^{\circ}C$ for 5 min.) and reimplanted bone, and resected, deep freezed with liquid nitrogen for 5 minutes and thawing in saline and reimplanted bone in the reconstruction of bilateral radial defects in each of 8, and in total 24 adult rabbits. The results were as follows : 1. Immediate histologic changes showed that intracortical osteocytes in lacunae were partially necrotized and the cortex were faintly stained with they Masson trichrome stain in both boiled and deep freezed groups, while they completely necrotized and their cortex stained more weakly with Masson trichrome stain in autoclaved group which means less amount of collagen and protein in cortex of long bone. 2. Radiographies at 8 weeks showed complete union with more marked incorporation and external callus formation in all boiled and freezed groups, whereas there was delayed union in four of sixteen (25%) in autoclaved group. Histologically, at 8 weeks after boiled and freezed, more intense incorporation with new bone formation and neovascularization were observed, whereas transverse clefts consisted with delayed union in 4 cases of autoclaved group (25%) were observed at osteotomy site. Through these studies, the boilod and deeply freezed bones acted as an osteoinductive material as well as osteoconductive, but the autoclaved bone only as osteoconductive. Though boilod and deeply freezed bone showed higher osteogenic potentials than autoclaved bone, the necrotizing effect on cortical and boiled bone was inferior to that of autoclaved. Thus the deeply freezed bone can be used for the treatment of aggressive benign or less malignant bone tumor not involving cortical bone, but the autoclaved bone supplemented with bone graft for the treatment of malignant bone tumor involving cortex of long bone.

• Journal of Periodontal and Implant Science
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• v.33 no.2
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• pp.289-299
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• 2003

The autogenous free gingival graft is the most predictable procedure currently used to increase the width of　the attached gingiva in periodontics. But the major disadvantage of the procedure is to create the multiple surgical wounds at both a donor site and a recipient site. The other problem is the limited amount of available　graft material in oral cavity. Therefore, recent researches have been focused to develop the biomaterial to substitute the autogenous gingival tissue. The purpose of this study was to evaluate the histologic healing after　grafting of bilayer artificial dermis, compared to the free gingival graft. Four non-smoking subjects (mean age, 32.5 years) in systemically healthy state and good oral hygiene were selected according to their particular needs for correction of mucogingival problems as suggested by Nabers(1966). The recipient sites were prepared through the procedure for the free gingival graft and were grouped according to the graft materials: Experimental group(n=5) - bilayer artifcia1 dermis ($Terudermis^{(R)}$; Terumo Co. Japan) and Control group(n=6) - free gingival graft with autogenous palatal mucosa. Biopsies were harvested at 1,2,3 and 6 weeks postsurgery to evaluate histologically. At the third week in the experimental group and at the second week of in the control group, the grafts has been clinically stabilized on the recipient bed and the graft border has been blended into the surrounding tissue. In the experimental group after 1 week of grafting, the epithelial migration from the adjacent tissue to graft material was seen and after 3 weeks of grafting, the : nflmmation decreased, collagen layer of the artificial dermis was lost and the basement membrane of epithelium was formed. After 6 weeks of grafting, both groups demonstrated orthokeratinized epithelium and increased thickness of epithelial tissue and the rete peg formation, similar to the adjacent tissue, Histologic evaluation revealed a biologic acceptance and incorporation of the collagen layers of the graft tissue to the host tissue, without foreign body reaction. In conclusion, a bilayer artificial dermis is essentially similar to autogeneous free gingival graft in the correction of mucogingival problems, and has the advantages of decreased patient morbidity (no donor site) and availability of abundant amounts of graft material when needed.