Evaluation of an Immune-privileged Scaffold for In vivo Implantation of Tissue-engineered Trachea

Shu Pan,Fei Sun,Hongcan Shi,Fangbiao Zhang,Xingchen Liu,Weidong Zhang 한국생물공학회 2014 Biotechnology and Bioprocess Engineering Vol.19 No.5

Forty tracheas were harvested from donor NewZealand rabbits. Thirty of the tracheas were randomlydivided into four treatment groups corresponding to 4, 5, 6,or 7% NaClO4 and one untreated group (n = 6 each group). Scanning electron microscopy distinctly revealed thecilium of epithelial cells in the fresh trachea. The internalsurface of the trachea was rough in the 4% treatment groupand smooth in the 5% treatment group, whereas the matrixwas fractured in the 6% treatment group and highlyfractured in the 7% treatment group. We observed that thenumber of nuclei in the cells of the 4, 5, 6, and 7%treatment groups decreased compared to the cells of theuntreated group (p < 0.05). Although there was a significantdecrease in maximum tensile strength, tensile strain atfracture and the elastic modulus (p < 0.05) with increasingconcentrations of NaClO4, the content of glycosaminoglycans(GAGs) did not significantly decline (p > 0.05) in the 5%treatment group. In addition, histopathological analysisshowed that the fiber component and basement membraneof the matrix in the 5% treatment group were retained afteroptimal decellularization. Despite the preserved cartilage,in vitro immunohistochemical analysis revealed that thematrix did not show the presence of major histocompatibilitycomplex (MHC) antigens. The remaining ten donor tracheas,which were divided into a positive control group and anoptimal decellularized group, were used for allogeneictransplantation. Blood samples were taken regularly, andhistologic examinations were performed at 30 days postimplantation,which showed no significant immune rejection. In conclusion, we surveyed the structural integrity throughmorphological observation and compared the biomechanicaland immunogenic changes in the tracheal matrix under thedifferent treatments. The optimal decellularized trachealmatrix with preserved cartilage, which was acquired via 5%NaClO4 treatment, exhibited structural integrity, antigen cellremoval and immune privilege and would be suitable for useas a tissue-engineered trachea for in vivo transplantation inrabbit models.

Synthesis and Biological Evaluation of Novel Benzimidazole Derivatives Bearing a Heterocyclic Ring at 4/5 Position

Reyila Wubulikasimu,Yanbing Yang,Fei Xue,Xianjin Luo,Dongping Shao,Yuhuan Li,Rongmei Gao,Weidong Ye 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.8

A series of novel benzimidazole derivatives bearing a heterocyclic ring as oxadiazole (21-32), thiadiazole (33- 34), triazole (35-36) were synthesized and evaluated for their activities against Coxsackie virus B3 and B6 in Vero cells. Compounds 21-26, 31-36 with moieties of 2'-pyridyl, 3'-pyridyl and 4'-pyridyl at the 2-position and oxadiazoles, thiadiazole, or triazole substituent at the 4- or 5-position generally displayed activities against CVB3 and CVB6. Especially compound 24 (IC50 = 1.08 μg/mL, SI = 61.7 against CVB3) was the promising candidate as lead compound for anti-enteroviral drug. It was observed in the incorporation of heterocyclic rings in benzimidazole at the 5-position could enhance their biological activities.

Sharpened VO₂ Phase Transition via Controlled Release of Epitaxial Strain

Lee, Daesu,Lee, Jaeseong,Song, Kyung,Xue, Fei,Choi, Si-Young,Ma, Yanjun,Podkaminer, Jacob,Liu, Dong,Liu, Shih-Chia,Chung, Bongwook,Fan, Wenjuan,Cho, Sang June,Zhou, Weidong,Lee, Jaichan,Chen, Long-Qin American Chemical Society 2017 NANO LETTERS Vol.17 No.9

<P>Phase transitions in correlated materials can be manipulated at the nanoscale to yield emergent functional properties, promising new paradigms for nanoelectronics and nanophotonics. Vanadium dioxide (VO2), an archetypal correlated material, exhibits a metal insulator transition (MIT) above room temperature. At the thicknesses required for heterostructure applications, such as an optical modulator discussed here, the strain state of VO2 largely determines the MIT dynamics critical to the device performance. We develop an approach to control the MIT dynamics in epitaxial VO2 films by employing an intermediate template layer with large lattice mismatch to relieve the interfacial lattice constraints, contrary to conventional thin film epitaxy that favors lattice match between the substrate and the growing film. A combination of phase-field simulation, in situ real-time nanoscale imaging, and electrical measurements reveals robust undisturbed MIT dynamics even at preexisting structural domain boundaries and significantly sharpened MIT in the templated VO2 films. Utilizing the sharp MIT, we demonstrate a fast, electrically switchable optical waveguide. This study offers unconventional design principles for heteroepitaxial correlated materials, as well as novel insight into their nanoscale phase transitions.</P>

Synthesis and Biological Evaluation of Novel Benzimidazole Derivatives Bearing a Heterocyclic Ring at 4/5 Position

Wubulikasimu, Reyila,Yang, Yanbing,Xue, Fei,Luo, Xianjin,Shao, Dongping,Li, Yuhuan,Gao, Rongmei,Ye, Weidong Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.8

A series of novel benzimidazole derivatives bearing a heterocyclic ring as oxadiazole (21-32), thiadiazole (33-34), triazole (35-36) were synthesized and evaluated for their activities against Coxsackie virus B3 and B6 in Vero cells. Compounds 21-26, 31-36 with moieties of 2'-pyridyl, 3'-pyridyl and 4'-pyridyl at the 2-position and oxadiazoles, thiadiazole, or triazole substituent at the 4- or 5-position generally displayed activities against CVB3 and CVB6. Especially compound 24 ($IC_{50}=1.08{\mu}g/mL$, SI = 61.7 against CVB3) was the promising candidate as lead compound for anti-enteroviral drug. It was observed in the incorporation of heterocyclic rings in benzimidazole at the 5-position could enhance their biological activities.

The 16-year experience in treating low-risk gestational trophoblastic neoplasia patients with failed primary methotrexate chemotherapy

Xiaodong Wu,Jiale Qin,Tao Shen,Weidong Fei,Lili Chen,Xing Xie,Weiguo Lu 대한부인종양학회 2020 Journal of Gynecologic Oncology Vol.31 No.4

Objective: To assess the outcomes and toxic effects of 5-day actinomycin D (Act-D) salvagetherapy and to explore the predictors of Act-D resistance in patients with low-risk gestationaltrophoblastic neoplasia (GTN)who failed 5-day methotrexate (MTX) chemotherapy. Methods: This retrospective study analyzed patients with low-risk GTN administered Act-Dsalvage therapy after failing MTX chemotherapy at Women's Hospital, School of MedicineZhejiang University between January 2000 and December 2015. The clinical parameters ofthese patients were collected and analyzed. Results: The final analysis included 89 cases. Of these, 73 cases (82.02%) responded tosalvage Act-D. The remaining 16 resistant cases were switched to etoposide, MTX, Act-D/cyclophosphamide, and vincristine chemotherapy and achieved complete remission. Serumhuman chorionic gonadotrophin levels before Act-D salvage therapy (hCGAct-D)in the Act-D resistant cases were significantly higher than those in the Act-D responders (median 605 vs. 103 IU/L, p=0.009). However, the range of hCGAct-D values in Act-D responders was wider thanthat in Act-D-resistant cases (5.76–16,664 IU/L vs. 11.43–6,732 IU/L). Thus, assigning a generalcut-off value was difficult considering the individual setting. Except for 2 cases requiring othersalvage regimens due to Act-D toxicity, 97.80% of cases (89/91) tolerated the toxicity. During atleast 1-year follow-up, the survival rate was 100.00% and no case developed recurrence. Conclusion: Based on the good therapeutic effect and tolerable toxicity, we recommendAct-D salvage therapy for all patients with low-risk GTN who fail primary MTX chemotherapy. The higher serum hCG levels before Act-D salvage therapy may be associated with resistanceto this treatment.

Substrate effect on phonon in graphene layers

Xiao Guo,Yongsong Wang,Siwen You,Dingbang Yang,Guiping Jia,Fei Song,Weidong Dou,Han Huang 한국탄소학회 2023 Carbon Letters Vol.33 No.5

Graphene exhibits high carrier mobility and concentration as well as other remarkable properties. Among them, the thermal behaviors of phonon modes play important roles in the application of optical and electronic devices. Here, A–A stacked graphene were proved well by Raman investigation on G and 2D modes. Temperature-dependent Raman scattering measurements on graphene with various number of layers on different substrates were conducted in the temperature range of 80–460 K. The first-order temperature coefficient of single layer graphene (SLG) on SiO2/ Si substrate is obviously smaller than that on Cu foil, indicating that the substrate effect attributes a great impact on graphene phonon temperature dependence. The first-order temperature coefficients of multilayer graphene linearly decrease as the number of layers increases, attributed to the reduction of substrate effect in phonon behaviors, rather than to the anharmonic phonon–phonon (ph–ph) coupling or thermal expansion.