Refolding Behavior of Urea-Induced Denaturation Collagen

Xu Wei,Yanqiu Zhao,Jingjing Zheng,Qin Cao,Sheng Li,Lang He,Benmei Wei,Juntao Zhang,Chengzhi Xu,Haibo Wang 한국고분자학회 2021 Macromolecular Research Vol.29 No.6

Exploration of the denaturation and refolding of natural collagen is important for the application of collagen and its denatured products. In this study, using urea as a denaturant, we prepared a denatured natural collagen product and analyzed its structural changes. The denaturation treatment severely destroyed the triple helix conformation of collagen, but had no significant effect on the primary structure of its α chains or the covalent cross-linking between α chains. Next, we observed the refolding behavior of the denatured collagen by removing urea through dialysis. We found that the denatured collagen products from different sources (grass carp skin, bovine tendon) all showed a reconstruction of the triple helix conformation up to 60-75% of the value of natural collagen during the refolding process. The telopeptide did not significantly promote triple helix reconstruction. In conclusion, the reconstruction of the α chains did not perfectly occur in a “head-to-head, tail-to-tail” manner in refolded collagen, as each α chain was participating in the reconstruction of multiple triple helix domains. The refolded collagen still had weak self-assembly ability and formed a unique network-like structure containing small interlaced and closely combined fibers, which shows favorable cell compatibility and potential applications.

Ground type-I collagen—a focused study on its fibrillogenesis behavior and bioactivity in vitro

Yuling Xu,Lei Dai,Ke Li,Jialin Liu,Haibo Wang,Lang He,Chengzhi Xu,Benmei Wei,Juntao Zhang 한국고분자학회 2023 Macromolecular Research Vol.31 No.1

Take bovine tendon type-I collagen as the raw material, we pretreated it by freezing and then grinding the macromolecule at a low temperature (4–10 °C). Effects of the grinding process on the molecular structure, water solubility, fibrillogenesis behavior in vitro and biological activity of collagen were systematically prospected. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) results revealed that the collagen had typical structural characteristics of type-I collagen; moreover, grinding treatment gave rise to partially degraded collagen molecules which took on continuous bands with lower molecular weights different from α1 and α2. More strikingly, the degradation degree positively corresponded to the grinding duration. Circular dichroism (CD) analysis manifested that with extended grinding, intensities of both the positive and negative peaks for collagen samples shrunk. Interestingly, grinding also contributed to improved water solubility of collagen. The water solubility of the sample ground for 20 min (COL20) was 1.91 mg/mL, which is about 6 times higher than that of the natural collagen sample (0.28 mg/mL). Amid the study concerning the fibrillogenesis behavior, turbidity and rheological data collaboratively demonstrated that with prolonged grinding time, the assembly rate and degree of the sample plunged. Assembled gel from the ground collagen with finer fibrils was also observed in scanning electron microscope (SEM), which further embraced the conclusion aforementioned in fibrillogenesis kinetics. Cell experiments corroborated that the grinding process can be harnessed to manipulate the cell proliferation promoting ability of collagen. Simultaneously, further dissection of COL20 with the best biological activity clarified that the water-soluble part and water-insoluble part of COL20 had distinct aptitudes as to promoting cell proliferation as well as inhibiting the growth of liver cancer cells.

CDH17 nanobodies facilitate rapid imaging of gastric cancer and efficient delivery of immunotoxin

Jingbo Ma,Xiaolong Xu,Chunjin Fu,Peng Xia,Ming Tian,Liuhai Zheng,Kun Chen,Xiaolian Liu,Yilei Li,Le Yu,Qinchang Zhu,Yangyang Yu,Rongrong Fan,Haibo Jiang,Zhifen Li,Chuanbin Yang,Chengchao Xu,Ying Long,J 한국생체재료학회 2022 생체재료학회지 Vol.26 No.4

Background: It is highly desirable to develop new therapeutic strategies for gastric cancer given the low survival rate despite improvement in the past decades. Cadherin 17 (CDH17) is a membrane protein highly expressed in cancers of digestive system. Nanobody represents a novel antibody format for cancer targeted imaging and drug delivery. Nanobody targeting CHD17 as an imaging probe and a delivery vehicle of toxin remains to be explored for its theragnostic potential in gastric cancer. Methods: Naïve nanobody phage library was screened against CDH17 Domain 1-3 and identified nanobodies were extensively characterized with various assays. Nanobodies labeled with imaging probe were tested in vitro and in vivo for gastric cancer detection. A CDH17 Nanobody fused with toxin PE38 was evaluated for gastric cancer inhibition in vitro and in vivo. Results: Two nanobodies (A1 and E8) against human CDH17 with high affinity and high specificity were successfully obtained. These nanobodies could specifically bind to CDH17 protein and CDH17-positive gastric cancer cells. E8 nanobody as a lead was extensively determined for tumor imaging and drug delivery. It could efficiently co-localize with CDH17-positive gastric cancer cells in zebrafish embryos and rapidly visualize the tumor mass in mice within 3 h when conjugated with imaging dyes. E8 nanobody fused with toxin PE38 showed excellent anti-tumor effect and remarkably improved the mice survival in cell-derived (CDX) and patient-derived xenograft (PDX) models. The immunotoxin also enhanced the anti-tumor effect of clinical drug 5-Fluorouracil. Conclusions: The study presents a novel imaging and drug delivery strategy by targeting CDH17. CDH17 nanobodybased immunotoxin is potentially a promising therapeutic modality for clinical translation against gastric cancer.

Existence and multiplicity of solutions for nonlinear Schr\"{o}dinger-Kirchhoff-type equations

Haibo Chen,Hongliang Liu,Liping Xu 대한수학회 2016 대한수학회지 Vol.53 No.1

In this paper, we consider the following Schr\"{o}dinger-Kirch\-hoff-type equations \[ \left[a+b\left(\int_{\mathbb{R}^{N}}(|\nabla u|^{2}+V(x)|u|^{2})dx\right)\right][-\Delta u+V(x)u]=f(x,u), ~~\mbox{in}~ \mathbb{R}^{N}. \] Under certain assumptions on $V$ and $f$, some new criteria on the existence and multiplicity of nontrivial solutions are established by the Morse theory with local linking and the genus properties in critical point theory. Some results from the previously literature are significantly extended and complemented.

Survival Association and Cell Cycle Effects of B7H3 in Neuroblastoma

Zhang, Haibo,Zhang, Jinsen,Li, Chunjie,Xu, Hao,Dong, Rui,Chen, Clark C.,Hua, Wei The Korean Neurosurgical Society 2020 Journal of Korean neurosurgical society Vol.63 No.6

Objective : The function of B7H3, a member of the B7 family of proteins, in neuroblastoma (NB) remains poorly characterized. Here we examine the expression pattern of B7H3 in clinical NB specimens and characterize the phenotype of B7H3 knock-down in NB cell line. Methods : Immunohistochemical (IHC) staining was carried out to assess the expression of B7H3 in clinical NB specimens. Survival association was analyzed using five Gene Expression Omnibus (GEO) datasets (GSE85047, GSE45480, GSE62564, GSE16476, GSE49710). Clonogenic survival and flow cytometry were performed after B7H3 knockdown to assess the cellular proliferation and cell survival in vitro. Impact of B7H3 silencing on NB growth was examined in vivo using the SH-SY5Y xenograft model. Results : On IHC staining, B7H3 was widely expressed in clinical NB specimens. Analysis of the transcriptional profiles of five GEO datasets clinically annotated NB specimens revealed that decreased B7H3 expression was associated with improved overall survival. B7H3 knockdown suppressed the proliferation of the SH-SY5Y NB model in vitro and in vivo. Cell cycle analysis revealed that B7H3 silencing induced G1/S arrest. This arrest was associated with the suppression of E2F1 expression and induction of Rb expression. Conclusion : Our results demonstrate that B7H3 expression correlate with clinical survival in NB patients. Preliminary studies suggest that B7H3 may mediate the G1/S transition.

The USP21/YY1/SNHG16 axis contributes to tumor proliferation, migration, and invasion of non-small-cell lung cancer

Pei Xu,Haibo Xiao,Qi Yang,Rui Hu,Lianyong Jiang,Rui Bi,Xueyan Jiang,Lei Wang,Ju Mei,Fangbao Ding,Jianbing Huang 생화학분자생물학회 2020 Experimental and molecular medicine Vol.52 No.-

Deubiquitinases (DUBs) and noncoding RNAs have been the subjects of recent extensive studies regarding their roles in lung cancer, but the mechanisms involved are largely unknown. In our study, we used The Cancer Genome Atlas data set and bioinformatics analyses and identified USP21, a DUB, as a potential contributor to oncogenesis in nonsmall-cell lung cancer (NSCLC). We further demonstrated that USP21 was highly expressed in NSCLCs. We then conducted a series of in vitro and in vivo assays to explore the effect of USP21 on NSCLC progression and the underlying mechanism involved. USP21 promoted NSCLC cell proliferation, migration, and invasion and in vivo tumor growth by stabilizing a well-known oncogene, Yin Yang-1 (YY1), via mediating its deubiquitination. Furthermore, YY1 transcriptionally regulates the expression of SNHG16. Moreover, StarBase bioinformatics analyses predicted that miR4500 targets SNHG16 and USP21. A series of in vitro experiments indicated that SNHG16 increased the expression of USP21 through miR-4500. In summary, the USP21/YY1/SNHG16 axis plays a role in promoting the progression of NSCLC. Therefore, the USP21/YY1/SNHG16/miR-4500 axis may be a potential therapeutic target in NSCLC treatment.

EXISTENCE AND MULTIPLICITY OF SOLUTIONS FOR NONLINEAR SCHRÖDINGER-KIRCHHOFF-TYPE EQUATIONS

CHEN, HAIBO,LIU, HONGLIANG,XU, LIPING Korean Mathematical Society 2016 대한수학회지 Vol.53 No.1

In this paper, we consider the following $Schr{\ddot{o}}dinger$-Kirchhoff-type equations $\[a+b\({\int}_{{\mathbb{R}}^N}({\mid}{\nabla}u{\mid}^2+V(x){\mid}u{\mid}^2)dx\)\][-{\Delta}u+V(x)u]=f(x,u)$, in ${\mathbb{R}}^N$. Under certain assumptions on V and f, some new criteria on the existence and multiplicity of nontrivial solutions are established by the Morse theory with local linking and the genus properties in critical point theory. Some results from the previously literature are significantly extended and complemented.

Investigation of random fatigue life prediction based on artificial neural network

Jie Xu,Chongyang Liu,Xingzhi Huang,Yaolei Zhang,Haibo Zhou,Hehuan Lian 국제구조공학회 2023 Steel and Composite Structures, An International J Vol.46 No.3

Time domain method and frequency domain method are commonly used in the current fatigue life calculation theory. The time domain method has complicated procedures and needs a large amount of calculation, while the frequency domain method has poor applicability to different materials and different spectrum, and improper selection of spectrum model will lead to large errors. Considering that artificial neural network has strong ability of nonlinear mapping and generalization, this paper applied this technique to random fatigue life prediction, and the effect of average stress was taken into account, thereby achieving more accurate prediction result of random fatigue life.

A 3-prismatic-revolute-spherical compliant parallel platform for optoelectronic packaging

Hongwei Xu,Haibo Zhou,Shuaixia Tan,Zhiping Kong,Ji-An Duan 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.6

To align the optical channels of optoelectronic appliances, a 3-prismaticrevolute-spherical (3-PRS) compliant parallel platform (CPP) is proposed in this work. The platform has special large stroke compliant joints. Attention is paid to the establishment of the inverse kinematics model and the analysis of the parasitic motion (PM) of the platform. A prototype of the platform is also presented, and its accuracy is experimentally evaluated. Besides, the platform is employed as a 3 degree-of-freedom (DOF) platform for optoelectronic packaging. Furthermore, the closed-loop control strategy requires merely one optical power meter to avoid the use of complex multiple DOF detection devices. In this respect, the influence of the precision of inverse kinematics solution on the optoelectronic packaging is reduced. Moreover, a compensation rule is employed to minimize the effect of PM on the motion accuracy of the platform. The results show that the proposed 3-PRS CPP is highly efficient for optoelectronic packaging.

Facile Synthesis of Fluorine Doped Graphitic Carbon Nitride with Enhanced Visible Light Photocatalytic Activity

Mengqiu Xu,Bo Chai,Juntao Yan,Haibo Wang,Zhandong Ren,Kyung-Wook Paik 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.12

Fluorine doped graphitic carbon nitride (g-C3N4) was successfully synthesized by a convenient co-polycondensation of urea and ammonium fluoride (NH4F) mixtures, and characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectra (FTIR), UV-Vis diffuse reflectance absorption spectra (UV-DRS), nitrogen adsorption–desorption, photoelectrochemical measurement and photoluminescence (PL) spectra. The photocatalytic activities of fluorine doped g-C3N4 samples were evaluated by the degradation of Rhodamine B (RhB) solution under visible light irradiation. The results showed that the fluorine doped g-C3N4 had a better photocatalytic activity than that of undoped g-C3N4, which was attributed to the favorable textural, optical and electronic properties derived from the fluorine atoms substituting nitrogen atoms of g-C3N4 frameworks. The photoelectrochemical measurements confirmed that the charges separation efficiency was improved by fluorine doping g-C3N4. Moreover, the tests of radical scavengers demonstrated that the holes (h+) and superoxide radicals (·O- 2 ) were the main active species for the degradation of RhB.