The use of integrin binding domain loaded hydrogel (RGD) with minimally invasive surgical technique in treatment of periodontal intrabony defect: a randomized clinical and biochemical study

Abstract Periodontal regeneration faces multiple challenges, the most important being cellular insufficiency. In an attempt to improve defect cellularity, we aimed to demonstrate enhancing cellular attraction using arginine-glycine-aspartic acid (RGD) adhesion molecule legend blended hydrogel within the intrabony defects. Methodology Forty-five intrabony defects were selected from patients with stage III or IV - grade A or B periodontitis and divided randomly into three equal groups of 15 each: group1 (G1): received minimally invasive surgical technique (MIST) alone, group2 (G2): received MIST and placebo hydrogel injection, and group3 (G3): were treated with MIST and RGD hydrogel injection. Primary outcomes 6 months following therapy were; defect base fill (DBF) and defect width measurement (DW); secondary outcomes were clinical attachment level (CAL), pocket depth (PD), plaque index (PI), gingival index (GI), and biochemical analysis of bone morphogenetic protein (BMP-2) evaluated at 1,7,14 and 21 days following therapy. Results Significant improvements in DBF, CAL, and PD were observed in the three studied groups 6 months following therapy compared to baseline (p<0.05). A significant improvement in DBF was reported in G3 compared to G1 and 2 (p=0.005). Additionally, a significantly higher CAL gain was reported in G3 compared to that of G1 (p=0.02). Group 3 was associated with a significantly higher level of BMP-2 compared to G1 and G2 in all reported periods. Conclusion RGD peptide carried on a hydrogel delivery agent and contained with a minimally invasive flap could be a reliable option in improving the outcomes of periodontal therapy.

Snake venom disintegrins update: insights about new findings

ABSTRACT Snake venom disintegrins are low molecular weight, non-enzymatic proteins rich in cysteine, present in the venom of snakes from the families Viperidae, Crotalidae, Atractaspididae, Elapidae, and Colubridae. This family of proteins originated in venom through the proteolytic processing of metalloproteinases (SVMPs), which, in turn, evolved from a gene encoding an A Disintegrin And Metalloprotease (ADAM) molecule. Disintegrins have a recognition motif for integrins in their structure, allowing interaction with these transmembrane adhesion receptors and preventing their binding to proteins in the extracellular matrix and other cells. This interaction gives disintegrins their wide range of biological functions, including inhibition of platelet aggregation and antitumor activity. As a result, many studies have been conducted in an attempt to use these natural compounds as a basis for developing therapies for the treatment of various diseases. Furthermore, the FDA has approved Tirofiban and Eptifibatide as antiplatelet compounds, and they are synthesized from the structure of echistatin and barbourin, respectively. In this review, we discuss some of the main functional and structural characteristics of this class of proteins and their potential for therapeutic use.

RGD peptide inhibits tumor growth by affecting angiogenesis related signaling pathway of laryngeal cancer stem cells / El péptido RGD inhibe el crecimiento tumoral al afectar la vía de señalización relacionada con la angiogénesis de las células madre del cáncer de laringe

SUMMARY: This study is to investigate the role and mechanism of RGD peptide in laryngeal cancer stem cells (CSCs). Laryngeal cancer CD133+Hep-2 CSCs were sorted by flow cytometry. RGD peptide was co-cultured with sorted laryngeal CSCs. Cell proliferation was detected with CCK-8 assay. The mRNA levels of VEGF/VEGFR2/STAT 3/HIF-1α were detected with RT-PCR. The proteins of VEGF/ VEGFR2/STAT 3/HIF-1α were detected with Western blot. The sorted CSCs were inoculated into nude mice. Tumor volume was measured. Integrin αvβ3 expression in tumor tissues was analyzed with immunohistochemistry. The results showed that the ratio of CD133+ CSCs to the total number of cells was 1.34±0.87 %, while CD133-non-tumor stem cells accounted for 95.0±5.76 %. The sorted cancer stem cells grew well. The RGD peptide significantly inhibited the proliferation of CD133+Hep-2 laryngeal CSCs in a dose-dependent manner. The RGD peptide significantly inhibited the mRNA of VEGFR2, STAT3 and HIF-1α in laryngeal CSCs in a concentration-dependent manner. Consistently, the RGD peptide significantly inhibited the protein expression of VEGFR2, STAT3 and HIF-1α in laryngeal CSCs in a dose-dependent manner. At the same time, in vivo tumor experiments showed that the RGD peptide significantly inhibited tumor volume but not the body weight. Furthermore, RGD peptide significantly inhibited the expression of tumor angiogenesis-related protein integrin αvβ3. Our findings demonstrate that RGD peptide inhibits tumor cell proliferation and tumor growth. The underlying mechanism may that RGD inhibits tumor angiogenesis-related signaling pathways, thus affecting the tumor angiogenesis, and decreasing the progression of human laryngeal CSCs.

Este estudio se realizó para investigar el papel y el mecanismo del péptido RGD en las células madre del cáncer de laringe (CSC). Las CSC CD133+Hep-2 de cáncer de laringe se clasificaron mediante citometría de flujo. El péptido RGD se cocultivó con CSC laríngeas clasificadas. La proliferación celular se detectó con el ensayo CCK-8. Los niveles de ARNm de VEGF/VEGFR2/ STAT 3/HIF-1α se detectaron con RT-PCR. Las proteínas de VEGF/ VEGFR2/STAT 3/HIF-1α se detectaron con Western blot. Las CSC clasificadas se inocularon en ratones nudos. Se midió el volumen del tumor. La expresión de integrina αvβ3 en tejidos tumorales se analizó con inmunohistoquímica. Los resultados mostraron que la proporción de CSC CD133+ con respecto al número total de células fue de 1,34 ± 0,87 %, mientras que las células madre no tumorales CD133 representaron el 95,0 ± 5,76 %. Las células madre cancerosas clasificadas crecieron bien. El péptido RGD inhibió significativamente la proliferación de CSC laríngeas CD133+Hep-2 de una manera dependiente de la dosis. El péptido RGD inhibió significativamente el ARNm de VEGFR2, STAT3 y HIF-1α en CSC laríngeas de manera dependiente de la concentración. De manera consistente, el péptido RGD inhibió significativamente la expresión proteica de VEGFR2, STAT3 y HIF-1α en CSC laríngeas, de manera dependiente de la dosis. Al mismo tiempo, los experimentos con tumores in vivo mostraron que el péptido RGD inhibía significativamente el volumen del tumor pero no el peso corporal. Además, el péptido RGD inhibió significativamente la expresión de la proteína integrina αvβ3 relacionada con la angiogénesis tumoral. Nuestros hallazgos demuestran que el péptido RGD inhibe la proliferación de células tumorales y el crecimiento tumoral. El mecanismo subyacente puede ser que RGD inhiba las vías de señalización relacionadas con la angiogénesis tumoral, afectando así la angiogénesis tumoral y disminuyendo la progresión de las CSC laríngeas humanas.

The anti-glioma effects of borneol and RGD co-modified docetaxel loaded nanoparticles after intranasal administration / 药学学报

Borneol (Bo) and Arg-Gly-Asp (RGD) co-modified docetaxel (DTX) loaded MPEG-PLGA nanoparticles (DTX-Bo-RGD-NPs) were prepared to improve the therapeutic effect of DTX against glioma after intranasal administration. DTX-Bo-RGD-NPs were prepared by emulsification-solvent evaporation method, and their morphology, particle size, zeta potential, drug loading capacity (DLC), stability, and in vitro release properties were investigated. The fluorescence probe coumarin-6 loaded NPs were prepared for investigating the NPs' uptake property on C6 and 16HBE cell models to evaluate in vitro targeting ability. The DiR loaded NPs were prepared for observing the fluorescence intensity at the brain tumor site after intranasal administration through in vivo imaging system in a C6 rat orthotropic model, evaluating the targeting ability in vivo. The anti-tumor effects of DTX-Bo-RGD-NPs were also investigated in such C6 rat orthotropic model in vivo. Animal welfare and experimental procedures are in compliance with the regulations of the Animal Ethics Committee of Shanghai University of Traditional Chinese Medicine. The results showed that DTX-Bo-RGD-NPs were spherical and uniformly distributed, with a particle size of about 140 nm and a zeta potential of -20 to -30 mV. The drug delivery system showed good stability and sustained release property in vitro, and favorable brain tumor targeting effect in vitro and in vivo. Such novel drug delivery system significantly improved the accumulation of DTX-Bo-RGD-NPs in tumor sites and displayed a higher brain tumor targeting efficiency, providing promising therapeutics of DTX for the treatment of glioma after intranasal administration.

Porous tantalum coated with RGD polypeptide can activate the integrin/focal adhesion kinase signaling pathway of MG63 cells / 中国组织工程研究

BACKGROUND: The compounding of RGD polypeptide on the surface of the material can induce the expression of osteoblast integrin gene, promote the adhesion of osteoblasts to the surface of biomaterials and differentiate into mature cells, and promote the formation of new bone. OBJECTIVE: To analyze the effect of domestic porous tantalum modified by RGD polypeptide on integrin/focal adhesion kinase signaling pathway in MG63 cells. METHODS: Porous tantalum material modified by RGD polypeptide was prepared. MG63 cells were inoculated on the surface of porous tantalum and porous tantalum materials modified with RGD polypeptide. MG63 cells cultured alone were used as the blank group. When cultured for 1, 3, 5, and 7 days, the cell proliferation was detected by the CCK-8 method. At 1, 3, and 5 days, the cell growth status was observed under an inverted microscope. At 3, 5 days of culture, cell adhesion was observed with scanning electron microscope. At 5 days of culture, RT-PCR and western blot assay were used to detect type I collagen and integrin β1 and focal adhesion kinase expression. RESULTS AND CONCLUSION: (1) The cell proliferation of the RGD modified group cultured at 3, 5, and 7 days was faster than that of the porous tantalum group and the blank group (P 0.05). (2) Observation by an inverted phase contrast microscope showed that the cells of the porous tantalum group and the RGD modified group were attached to the edge of the material when cultured for 1 day, and the number of cells gradually increased with the extension of the culture time. The number and density of cells in the RGD modified group were better than that of the porous tantalum group. (3) Observation by scanning electron microscope showed that cells adhered to the surface of the porous tantalum group and RGD modified group after 3 days of culture. The cells adhered to the material pore walls and pores, and protruded pseudopods into the pores. When cultured for 5 days, the cells secreted a large amount of extracellular matrix, and the cells were connected to each other through the matrix and gradually covered the surface of the material. The cell growth state, matrix secretion and cell coverage area of the RGD modified group were better than those of the porous tantalum group. (4) Western blot detection results showed that the expressions of type I collagen and integrin β1 protein in the RGD modified group were higher than those in the porous tantalum group and the blank group (P < 0.05). The expression levels of type I collagen, integrin β1, and focal adhesion kinase protein in the porous tantalum group were higher than those in the blank group (P < 0.05). (5) RT-PCR detection showed that the expressions of type I collagen, integrin β1, and focal adhesion kinase mRNA in the RGD modified group were higher than those of the porous tantalum group and the blank group (P < 0.05), and the expression of the porous tantalum group was higher than that of the blank group (P < 0.05). (6) The results showed that porous tantalum modified with RGD polypeptide can up-regulate the expression of type I collagen and integrin β1 on the cell membrane, activate the integrin/focal adhesion kinase signaling pathway, and promote cell adhesion and growth.

D-RADA16-RGD-Reinforced Nano-Hydroxyapatite/Polyamide 66 Ternary Biomaterial for Bone Formation

BACKGROUND: Nano-hydroxyapatite/polyamide 66 (nHA/PA66) is a composite used widely in the repair of bone defects. However, this material is insufficient bioactivity. In contrast, D-RADA16-RGD self-assembling peptide (D-RADA16-RGD sequence containing all D-amino acids is Ac-RADARADARADARADARGDS-CONH2) shows admirable bioactivity for both cell culture and bone regeneration. Here, we describe the fabrication of a favorable biomaterial material (nHA/PA66/D-RADA16-RGD). METHODS: Proteinase K and circular dichroism spectroscopy were employed to test the stability and secondary structural properties of peptide D-RADA16-RGD respectively. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the surface of these materials. Confocal laser scanning (CLS), cell counting kit-8 tests (CCK-8), alizarin red S staining, cell immunofluorescence analysis and Western blotting were involved in vitro. Also biosafety and bioactivity of them have been evaluated in vivo. RESULTS: Proteinase K and circular dichroism spectroscopy demonstrated that D-RADA16-RGD in nHA/PA66 was able to form stable-sheet secondary structure. SEM and TEM showed that the D-RADA16-RGD material was 7–33 nm in width and 130–600 nm in length, and the interwoven pore size ranged from 40 to 200 nm. CLS suggests that cells in nHA/PA66/D-RADA16-RGD group were linked to adjacent cells with more actin filaments. CCK-8 analysis showed that nHA/PA66/D-RADA16-RGD revealed good biocompatibility. The results of Alizarin-red S staining and Western blotting as well as vivo osteogenesis suggest nHA/PA66/D-RADA16-RGD exhibits better bioactivity. CONCLUSION: This study demonstrates that our nHA/PA66/D-RADA16-RGD composite exhibits reasonable mechanical properties, biocompatibility and bioactivity with promotion of bone formation.

Tumor targeting and suppression effect in nude mice induced by rgd and r8 peptides modifieds liposomes loading ergosterol and cisplatin / 中国药学杂志

OBJECTIVE: To preliminarily evaluate the targeting and anti-lung cancer effect in vivo in nude mice induced by Cyclo (RGD) and R8 peptides modified ergosterol combined cisplatin liposomes. METHODS: The first step, injected RGD cyclo peptide and R8 peptide-modified, single modified or no modified ergosterol combined cisplatin liposome in the caudal vein of nude mouse bearing the tumor, the body distribution and targeting of each group under the different time points through small animals living imager were observed. The second step, continuously, dose every other day for 14 d, observating the weight of mice and the tumor growth situation. The animals were drawed blood and then were put to death, removing the tumor, the spleen and the lung tissue of all the mice. As the index of the tumor weight, the tumor suppression effect, the level of TGF-β1, TIMPs and TNF-α in serum, the spleen index and changes of the tumor and lung tissue, investigate the tumor suppression effect in mice of the liposomes preliminary. RESULTS: The targeting result of tumor-bearing nude mice displays that the fluorescence intensity of RGD and R8 peptides-modified liposome is the highest and the targeting is most obvious under high concentration and other group of liposome are weaker. Preliminary pharmacodynamics results show that each dosage group of mice have no obvious change in body weight and the high and middle dose group of RGD and R8 peptides-modified liposomes has tumor suppression effect obviously. The high dose group of RGD and R8 peptides-modified liposome is the most significant. It has high expression of cytokines (TNF-α) in serum. The spleen index of middle and low dose group of RGD and R8 peptides-modified liposomes significantly increased compared with positive medicine group. CONCLUSION: RGD cyclo peptide and R8 peptide-modified ergosterol combined cisplatin targeting liposome drug delivery system further improves the tumor targeting and anti-lung cancer effect in vivo.

Effects of RGD-grafted TiO2 nanotubes on the adhesion and proliferation of MG63 osteoblasts / 口腔疾病防治

Objective@#To investigate the effect of pure titanium surface of large diameter TiO2 nanotubes modified by RGD peptide on the adhesion and proliferation of MG63 osteoblasts. to provide theoretical proof for developing titanium implants.@*Methods@#Commercially pure titanium discs were divided into four groups and treated with SLA to obtain a microrough surface (SLA group). Then, nanotubes were imposed on this microrough surface by anodization (SLA+80 group). The surface was then modified by dopamine (DOPA) (DOPA Group), after which bioactive RGD peptide layers were generated on the TiO2 nanotube surfaces via electrochemical and molecular self-assembly techniques (RGD group). The titanium surface morphology and elemental composition of each group were characterized by field emission scanning electron microscopy (FE-SEM) and X-ray photoelectron spectroscopy (XPS). MG63 cells were cultured in vitro to evaluate biological activities of titanium before and after treatment, including the evaluation of early-stage cell adhesion capacity by fluorescence microscopy, proliferation capacity by MTS assay, and mRNA expression of the cell osteoblast-related genes alkaline phosphatase (ALP) and osteocalcin (OCN) by qRT-PCR.@*Results@#FE-SEM and XPS showed that hierarchical micro/nanosurfaces decorated with TiO2 nanotubes were produced on titanium using sandblasting and large grit etching combined with anodization, dopamine was then self-polymerized to form a polydopamine film on the TiO2 nanotube surfaces, and RGD peptides were then conjugated to the polydopamine film, finally forming RGD peptide-modified bioactive layers. In vitro experiments showed that compared with the other three materials, the RGD-modified material was more conducive to cell adhesion and proliferation (P < 0.05). The expression levels of ALP and OCN mRNA in the RGD group were significantly higher than those in the SLA group and DOPA group (P < 0.05).@*Conclusion@#Hierarchical micro/nanosurfaces decorated with TiO2 nanotubes functionally modified with RGD peptides have good biocompatibility and could be used for developing titanium implants and further improving early osseointegration.

Progress on clinical application of RGD tripeptide / 基础医学与临床

The integrin is a family of membrane receptor proteins composed of heterologous dimer , it can identify the sequence RGD .Integrin excessive expressed in tumor cells and angiogenesis .Using their special relationship a-mong them, the RGD as the carrier, combined with the radioactive tracer , antineoplastic drugs and other substances,which has tumoraffin imaging ,targeted anticancer therapy ,anti-inflammatory,anti depression effect and bone and nerve repair , and so on .

Synergistic Effect of Cold Plasma Treatment and RGD Peptide Coating on Cell Proliferation over Titanium Surfaces

The aim of this study was to investigate the synergistic effect of cold atmospheric plasma (CAP) treatment and RGD peptide coating for enhancing cellular attachment and proliferation over titanium (Ti) surfaces. The surface structure of CAP-treated and RGD peptide-coated Ti discs were characterized by contact angle goniometer and atomic force microscopy. The effect of such surface modification on human bone marrow derived mesenchymal stem cells (hMSCs) adhesion and proliferation was assessed by cell proliferation and DNA content assays. Besides, hMSCs' adhesion and morphology on surface modified Ti discs were observed via fluorescent and scanning electron microscopy. RGD peptide coating following CAP treatment significantly enhanced cellular adhesion and proliferation among untreated, CAP-treated and RGD peptide-coated Ti discs. The treatment of Ti surfaces with CAP may contribute to improved RGD peptide coating, which enables increased cellular integrations with the Ti surfaces.

Cell migration inhibition activity of a non-RGD disintegrin from Crotalus durissus collilineatus venom

In recent decades, snake venom disintegrins have received special attention due to their potential use in anticancer therapy. Disintegrins are small and cysteine-rich proteins present in snake venoms and can interact with specific integrins to inhibit their activities in cell-cell and cell-ECM interactions. These molecules, known to inhibit platelet aggregation, are also capable of interacting with certain cancer-related integrins, and may interfere in important processes involved in carcinogenesis. Therefore, disintegrin from Crotalus durissus collilineatus venom was isolated, structurally characterized and evaluated for its toxicity and ability to interfere with cell proliferation and migration in MDA-MB-231, a human breast cancer cell line. Methods: Based on previous studies, disintegrin was isolated by FPLC, through two chromatographic steps, both on reversed phase C-18 columns. The isolated disintegrin was structurally characterized by Tris-TricineSDS-PAGE, mass spectrometry and N-terminal sequencing. For the functional assays, MTT and wound-healing assays were performed in order to investigate cytotoxicity and effect on cell migration in vitro, respectively. Results: Disintegrin presented a molecular mass of 7287.4 Da and its amino acid sequence shared similarity with the disintegrin domain of P-II metalloproteases. Using functional assays, the disintegrin showed low cytotoxicity (15% and 17%, at 3 and 6 µg/mL, respectively) after 24 h of incubation and in the wound-healing assay, the disintegrin (3 µg/mL) was able to significantly inhibit cell migration (24%, p < 0.05), compared to negative control. Conclusion: Thus, our results demonstrate that non-RGD disintegrin from C. d. collilineatus induces low cytotoxicity and inhibits migration of human breast cancer cells. Therefore, it may be a very useful molecular tool for understanding ECM-cell interaction cancer-related mechanisms involved in an important integrin family that highlights molecular aspects of tumorigenesis. Also, non-RGD disintegrin has potential to serve as an agent in anticancer therapy or adjuvant component combined with other anticancer drugs.(AU)

A Systematic Comparative Evaluation of ⁶⁸Ga-Labeled RGD Peptides Conjugated with Different Chelators / 대한핵의학회잡지

PURPOSE: The present paper reports a systematic study on the effect of bifunctional chelators (BFC) namely, NOTA, DOTA, and DTPA, on the radiochemical formulation, in vitro stability, and in vivo biological properties of ⁶⁸Ga-labeled RGD peptide derivatives.METHODS: The three RGD conjugates namely, NOTA-Bn-E-[c(RGDfk)]₂, DOTA-Bn-E-[c(RGDfk)]₂, and DTPA-Bn-E-[c(RGDfk)]₂ were radiolabeled with ⁶⁸Ga and the radiolabeling was optimized with respect to the ligand amount, radiolabeling time, and temperature. Further, the ⁶⁸Ga complexes were assessed for their in vitro and in vivo stabilities. The biodistribution studies of the three radiolabeled conjugates were carried out in C57BL/6 mice bearing melanoma tumor at 30 min and 1 h post-adimistration.RESULTS: NOTA-Bn-E-[c(RGDfk)]₂ could be radiolabeled with ⁶⁸Ga at room temperature while DOTA-Bn-E-[c(RGDfk)]₂ and DTPA-Bn-E-[c(RGDfk)]₂ were radiolabeled at high temperature. ⁶⁸Ga-NOTA-Bn-E-[c(RGDfk)]₂ was found to be the most kinetically rigid in in vitro stability assay. The uptake of the three radiolabeled peptide conjugates in melanoma tumor was comparable at 1 h post-administration (NOTA; DOTA; DTPA (% I.D./g):: 2.78 ± 0.38; 3.08 ± 1.1; 3.36 ± 0.49). However, the tumor/background ratio of ⁶⁸Ga-NOTA-Bn-E-[c(RGDfk)]₂ was the best amongst the three radiotracers. ⁶⁸Ga-complexes of NOTA-Bn-E-[c(RGDfk)]₂ and DOTABn-E-[c(RGDfk)]₂ showed excellent in vivo stability while ⁶⁸Ga-DTPA-Bn-E-[c(RGDfk)]₂ showed significant metabolic degradation.CONCLUSION: These studies show that ⁶⁸Ga-NOTA-Bn-E-[c(RGDfk)]₂ would be the most appropriate ⁶⁸Ga-labeled radiotracer and the most amenable for kit formulation.

Engineered M13 Nanofiber Accelerates Ischemic Neovascularization by Enhancing Endothelial Progenitor Cells

Dysfunction or loss of blood vessel causes several ischemic diseases. Although endothelial progenitor cells (EPCs) are a promising source for cell-based therapy, ischemia-induced pathophysiological condition limits the recovery rate by causing drastic cell death. To overcome this issue, we attempted to develop a cell-targeted peptide delivery and priming system to enhance EPCbased neovascularization using an engineered M13 bacteriophage harboring nanofibrous tubes displaying ∼ 2700 multiple functional motifs. The M13 nanofiber was modified by displaying RGD, which is an integrin-docking peptide, on the minor coat protein, and bymutilayering SDKPmotifs,which are the key active sites for thymosin b4, on themajor coat protein. The engineered M13 nanofiber dramatically enhanced ischemic neovascularization by activating intracellular and extracellular processes such as proliferation, migration, and tube formation in the EPCs. Furthermore, transplantation of the primed EPCs with the M13 nanofiber harboring RGD and SDKP facilitated functional recovery and neovascularization in a murine hindlimb ischemia model. Overall, this study demonstrates the effectiveness of theM13 nanofiber-based novel peptide deliveryandprimingstrategy inpromotingEPC bioactivity and neovessel regeneration. To our knowledge, this is first report onM13 nanofibers harboring dual functional motifs, the use of which might be a novel strategy for stem and progenitor cell therapy against cardiovascular ischemic diseases.

Progress on radionuclide-labeled small peptides in targeting tumor angiogenesis / 中国肿瘤临床

Early diagnosis and precision medicine generally show significant differences in the prognosis of patients with carcinoma. Angiogenesis not only plays a key role in tumor pathophysiology but also acts as an important drug target. Peptides with specific se-quences can target specific molecules on the endothelial cellular membrane during tumor angiogenesis. Radionuclide-labeled molecu-lar probes exhibit many advantages in oncotherapy. This article focuses on the progress of radionuclide-labeled RGD and RRL in radio-immunoimaging and radioimmunotherapy targeting tumor angiogenesis.

Osteopontin Peptide Icosamer Containing RGD and SLAYGLR Motifs Enhances the Motility and Phagocytic Activity of Microglia

Osteopontin (OPN) is a secreted glycoprotein that is expressed in various tissues, including brain, and mediates a wide range of cellular activities. In a previous study, the authors observed the robust neuroprotective effects of recombinant OPN and of RGD and SLAYGLR-containing OPN-peptide icosamer (OPNpt20) in an animal model of transient focal ischemia, and demonstrated anti-inflammatory and pro-angiogenic effects of OPNpt20 in the postischemic brain. In the present study, we investigated the effects of OPNpt20 on the motility and phagocytic activity of BV2 cells (a microglia cell line). F-actin polymerization and cell motility were significantly enhanced in OPNpt20-treated BV2 cells, and numbers of filopodia-like processes increased and lamellipodia-like structures enlarged and thickened. In addition, treatment of cells with either of three mutant OPN icosamers containing mutation within RGD, SLAY, or RGDSLAY showed that the RGD and SLAY motifs of OPNpt20 play critical roles in the enhancement of cell motility, and the interaction between exogenous OPNpt20 and endogenous αv and α4 integrin and the activations of FAK, Erk, and Akt signaling pathways were found to be involved in the OPNpt20-mediated induction of cell motility. Furthermore, phagocytic activity of microglia was also significantly enhanced by OPNpt20 in a RGD and SLAY dependent manner. These results indicate OPNpt20 containing RGD and SLAY motifs triggers microglial motility and phagocytic activity and OPNpt20-integrin mediated signaling plays a critical role in these activities.

Preparation of Vinorelbine-tetrandrine Liposomes Modified with RGD and Study on the in vitro Antitumor Effect / 中国药房

OBJECTIVE:To prepare the vinorelbine-tetrandrine liposomes modified with RGD,and study the inhibitory effect on glioma C6 cells. METHODS:Film dispersion method and ammonium sulfate gradient method were used to prepare the vinorel-bine-tetrandrine liposomes modified with RGD,and the morphology and particle size distribution were observed. The vinorelbine content was determined,and sulforhodamine B method was used to respectively determine the inhibitory effects of blank targeting liposomes,normal vinorelbine liposomes and vinorelbine-tetrandrine liposomes modified with RGD on C6 cells. RESULTS:The prepared vinorelbine-tetrandrine liposomes modified with RGD were spherical or almost spherical with smooth surface,and particle size was about 120 nm. The average content of vinorelbine was 28.27 μg/mL(RSD=0.38％,n=3). Blank targeting liposomes had no significant effect on the growth of C6 cells;vinorelbine-tetrandrine liposomes modified with RGD can obviously inhibit the growth of C6 cells,and cell viability after its effect was significantly lower than normal vinorelbine liposomes (P<0.05). CON-CLUSIONS:Vinorelbine-tetrandrine liposomes modified with RGD are successfully prepared,and they show obvious inhibitory ef-fects on the growth of C6 cells.

⁶⁸Gallium-Arginine-Glycine-Aspartic Acid and ¹⁸F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in Chondroblastic Osteosarcoma of the Skull / 대한핵의학회잡지

We report the case of a 32 year-old male with Chondroblastic Osteosarcoma of the skull, which was imaged with both ¹⁸[F]fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) and ⁶⁸Gallium-arginine-glycine-aspartic acid (⁶⁸Ga-RGD) PET/CT. The ¹⁸F-FDG PET/CT did not demonstrate the tumour,whereas the ⁶⁸Ga-RGD PET/CT clearly depicted a left-sided frontal tumour. ⁶⁸Ga-RGD PET/CT may be a clinically useful imaging modality for early detection of recurrent osteosarcoma, considering the limitations of ¹⁸F-FDG PET in a setting of low glycolytic activity.

pH-sensitive micelles loaded paclitaxel using carboxymethyl chitosan-palmitic acid mediated by cRGD / 药学学报

cRGD-carboxymethyl chitosan-palmitic acid (cRGD-CMCh-PA) was synthesized and a pHsensitive paclitaxel-loaded cRGD-CMCh-PA micelles (PTX-cRGD-CMCh-PA) was prepared with the film dispersion method; related substances were characterized by FT-IR and 1H NMR. PTX-cRGD-CMCh-PA micelles were studied with the particle size distribution, zeta potential, morphology and release behavior in vitro was investigated by the method of equilibrium dialysis. In vitro cytotoxicity of different formulations on A549 cells was tested by MTT assay. The uptake process of micelles was explored using confocal microscopy and a live cell station was used to observe the dynamic phagocytosis. The subcutaneous and orthotropic tumor models were built to study the distribution of DiR-labeled micelles by near-infrared fluorescence (NIR) imaging system. The FT-IR spectra and 1H NMR spectra confirmed the successful conjugation of cRGD-CMCh-PA polymer and the degree of carboxymethyl and the palmitic acid grafted on chitosan were 45.0% and 15.0%. PTX-cRGD-CMCh-PA micelles were prepared with particle size of (162.9±1.5) nm, zeta potential of +26.3 mV and encapsulation efficiency and the drug loading of 99.67% and 28.5%, respectively. The micelles released slowly in pH 7.4 whose release curves were accorded with the Higuchi equation; they had an initial burst effect in second hours and showed a pH sensitive release behavior in pH 5.3. The IC50 of PXT-CMCh-PA and PTX-cRGD-CMCh-PA were 2.077 μg·mL-1 and 0.876 μg·mL-1, respectively. The cells uptake process of micelles in A549 cells revealed that the micelles were mainly co-located with lysosome and PTX-cRGD-CMCh-PA showed much better targeting effect. The NIR fluorescence imaging results showed that the micelles had a good targeting effect on both subcutaneous and orthotropic tumors. In this study, a novel copolymer cRGDCMCh-PA was synthesized with a sustained and pH-dependent drug release activity which would potentially become a new carrier for hydrophobic drugs.

Preparation of RGD-targeted Microbubble Contrast Agent and Its Adhesion Efifcacy / 中国医学影像学杂志

PurposeTo develop a novel RGD microbubbles (RGD-MBs) and to evaluate the targeted binding effect with endothelial cells in vitro.Materials and MethodsThe RGD peptide was coated onto the microbubbles through biotin-avidin linkage including 10 μg/ml and 30 μg/ml groups. The microbubbles not carrying RGD peptide were obtained as negative control. Blocking studies were performed with pre-incubation of the cells with RGD peptide for 2 hours. The microbubbleswere characterized by Accusizer 780 and optical microscope. The binding specificity of RGD-MBs withανβ3-expressing mouse endothelial cells was determined with competitive inhibition experiments in vitro. The attachment study was performed using parallel plate flow chamber to investigate the dynamic adhesion on endothelial cells at various shear stresses.ResultsThe RGD-MBs had an average diameter of (4.09±0.07) μm. The binding RGD-MBs per cell were 2.98±0.35 for 10 μg/ml RGD and 1.78±0.23 for 30 μg/ml RGD. RGD-MBs binding to mouse endothelial cells decreased 54.64% and 67.00% in the presence of RGD peptide at a concentration of 10 μg/ml and 30 μg/ml respectively. When the shear stress was under 1.5 dyne/cm2, the accumulation rate was increased with the increase of shear stress (P1.5 dyne/cm2 (P<0.05). Conclusion The RGD-MBs can specifically bind to endothelial cells, indicating its usefulness as ultrasonic molecular probe in monitoring integrinανβ3 expression during tumor angiogenesis, and is potentially valuable for in tumor early-staging and prognosis.

PRGD composite nerve conduit in repair of human peripheral nerve defect in upper extremity / 中华显微外科杂志

Objective To explore the clinical efficacy of PRGD composite nerve conduit in the treatment of human large-diameter,critical peripheral nerve defect in upper extremity.Methods From December,2011 to August,2014,19 patients with large-diameter,critical peripheral nerve defect in upper extremity were treated with PRGD composite nerve conduit.The patients were followeded-up periodically.The sensory and motor function recovery,high frequency ultrasound,and EMG were employed to assess the efficacy.Results The patients were followed up for an average time of 12-32 months(mean 21.75 ± 6.86 months),sensory and motor function recovered excellent in 7 patients,satisfactory in 7 patients,tolerable in 3 patients and no improvement in 2 patients were obtained according to the peripheral nerve function assessment standard built by British medical research council,the rate excellent and satisfactory results was 73.7％.Conclusion It is clinically promising to use PRGD composite nerve conduit to repair large-diameter,critical peripheral nerve defect in upper extremity,thus laying a foundation for its further application in clinical practice.