• 생명과학회지
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• 제23권11호
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• pp.1409-1414
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• 2013

림프절은 체내로 침입한 병원체에 반응하여 성숙한 림프구들이 활성화 되는 곳이다. 림프구들은 스트로마의 구조적 뼈대를 따라 동계항원을 제시하고 있는 항원제시세포의 표면을 탐색한다. Fibroblastic reticular cells(FRC)는 림프절 T zone에서 3차원구조 네트워크를 형성하는데 관여하는 스트로마 세포로 유입되는 T 림프구들에 대한 안내길을 제공한다. 이런 상호 협력적인 환경에서 FRC와 T세포의 양방향적 관계는 림프절의 정상적 기능을 수행하는데 필수적이다. FRC는 물리적으로 림프절 조형물을 형성 할 뿐만 아니라 T세포 생물학적 기능조절에도 필수적이다. FRC는 T 림프구와 상호 반응하며 T세포에 발판을 제공하고 T세포 면역반응에 영향을 미치는 용해성 인자들을 방출한다. 최근에는 FRC는 말초에서 자기 관용 T세포 생성에도 관여하며 림프절에서 활성화된 T세포 분열을 조절하는데도 관여하고 있다. 따라서, FRC와 T세포 상호간 협력은 림프절에서 T세포기능을 조절하는데 중요한 결과를 야기한다. 더욱이, FRC는 염증 상황에서 항생펩타이드, 보체 등의 분비를 통한 선천성 면역에도 중요한 역할도 한다. 결론적으로 FRC와 T세포 상호간에 T세포 생물학적 효능을 증대를 위해 양방향성 접촉을 하며 이러한 상호 협력적 피드백은 면역반응 동안 조직기능 유지를 돕게 된다.

• Nutritional Sciences
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• 제9권4호
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• pp.233-239
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• 2006

Porous matrices of bioactive polymers such as polyglycolic acid (PGA) or polylactic acid (PLA) can be used as scaffolds in bone tissue growth during bone repair process. These polymers are highly porous and serve as a template for the growth and organization of new bone tissues. We evaluated the effect of PGA and PLA polymers on osteoblastic MC3T3-E1 cell extracellular mineralization. MC3T3-E1 cells were cultured in a time-dependent manner -1, 15, 25d as appropriate - for the period of bone formation stages in one of the five culture circumstances, such as normal osteogenic differentiation medium, PGA-plated, fetal bovine serum (FBS)-plated, PGA/FBS-coplated, and PLA-plated For the evaluation of bone formation, minerals (Ca, Mg, Mn) and alkaline phosphatase activity, a marker for osteoblast differentiation, were measured Alizarin Red staining was used for the measurement of extracellular matrix Ca deposit During the culture period, PGA-plated one was reabsorbed into the medium more easily and faster than the PLA-plated one. At day 15, at the middle stage of bone formation, cellular Ca and Mg levels showed higher tendency in PGA- or PLA-plated treatments compared to non-plated control and at day 25, at the early late stage of bone formation, all three cellular Ca, Mg or Mn levels showed higher tendency as in order of PGA-related treatments and PLA-plated treatments, compared to control even without significance. Medium Ca, Mg or Mn levels didn't show any consistent tendency. Cellular ALP activity was higher in the PGA- or PLA-plated treatments compare to normal osteogenic medium treatment PGA-plated and PGA/FBS-plated treatments showed better Ca deposits than other treatments by measurement of Alizarin Red staining, although PLA-plated treatment also showed reasonable Ca deposit. The results of the present study suggest that biodegradable material, PGA and also with less extent for PLA, can be used as a biomaterial for better extracellular matrix mineralization in osteoblastic MC3T3-E1 cells.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권5호
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• pp.366-374
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• 2010

Introduction: This study evaluated the capability of silk fibroin (SF) and recombinant human bone morphogenetic protein-2 loaded SF (SF-BMP) as a bone defect replacement matrix when grafted in a calvarial bone defect of rats in vivo. Materials and Methods: A total 70 calvarial critical size defects (5.0 mm in diameter) made on 35 adult female Sprague-Dawley rats were used in this study. The defects were transplanted with (1) rhBMP-2 loaded silk fibroin graft (SF-BMP: 0.8+$10\;{\mu}g$), (2) Silk fibroin (SF: $10\;{\mu}g$), and (3) no graft material (Raw). The samples were evaluated with soft x-rays, alkaline phosphatase activity, calcium/phosphate quantification, histological and histomorphometric analysis at postoperative 4 and 8 weeks. Results: The SF-BMP group ($48.86{\pm}14.92%$) had a significantly higher mean percentage bone area than the SF group ($24.96{\pm}11.01%$) at postoperative 4 weeks.(P<0.05) In addition, the SF-BMP group ($40.01{\pm}12.43%$) had a higher % bone area at postoperative 8 weeks than the SF group ($33.26{\pm}5.15%$). The mean ratio of gray scale levels to the host bone showed that the SF-BMP group ($0.67{\pm}0.08$) had a higher mean ratio level than the SF group ($0.61{\pm}0.09$) at postoperative 8 weeks. These differences were not statistically significant.(P=0.168 and P=0.243, respectively) The ratio of the calcium and phosphate contents of the SF-BMP ($0.93{\pm}0.22$) group was lower than that of the SF ($1.90{\pm}1.42$) group at postoperative 4 weeks. However, the SF-BMP group ($0.75{\pm}0.31$) had a higher Ca/$PO_4$ ratio than the SF ($0.68{\pm}0.04$) at postoperative 8 weeks. These differences were not statistically significant.(P=0.126 and P=0.627, respectively) For the bone-specific alkaline phosphatase (ALP) activity, which is recognized as a reliable indicator of the osteoblast function, the SF-BMP ($23.71{\pm}8.60\;U/L$) groups had a significantly higher value than the SF group ($12.65{\pm}6.47\;U/L$) at postoperative 4 weeks.(P<0.05) At postoperative 8 weeks, the SF-BMP ($21.65{\pm}10.02\;U/L$) group had a lower bone-specific ALP activity than the SF group ($16.72{\pm}7.35\;U/L$). This difference was not statistically significant.(P=0.263) For the histological evaluation, the SF-BMP group revealed less inflammation, lower foreign body reactions and higher bone healing than the SF group at postoperative 4 and 8 weeks. The SF group revealed more foreign body reactions at postoperative 4 weeks. However, this immunogenic reaction decreased and the remnant of grafted material was observed at postoperative 8 weeks. For histomorphometric analysis, the SF-BMP group had a significantly longer bone length to total length ratio than those of the SF group at postoperative 4 and 8 weeks.(P<0.05) Conclusion: The rhBMP-2 loaded silk fibroin graft revealed fewer immunoreactions and inflammation as well as more new bone formation than the pure silk fibroin graft. Therefore, silk fibroin may be a candidate scaffold for tissue engineered bone regeneration.