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Yasami-Khiabani S, Karkhaneh A, Shokrgozar MA, Amanzadeh A, Golkar M. Size effect of human epidermal growth factor-conjugated polystyrene particles on cell proliferation. Biomater Sci 2020; 8:4832-4840. [PMID: 32760979 DOI: 10.1039/d0bm00183j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Conjugation of growth factors to a carrier is a favorable method to improve their efficacy as therapeutic molecules. Here, we report the carrier size effect on bioactivity of human epidermal growth factor (hEGF) conjugated to polystyrene particles. BALB/3T3 cells were treated with hEGF-conjugated particles (hEGF-conjs) sized from 20 to 1000 nm. At hEGF concentrations less than 0.5 ng ml-1, free hEGF was more potent than the hEGF-conjs at inducing cell proliferation. However, cell proliferation was size-dependent at higher concentrations of hEGF i.e. hEGF-conjs sized equal to or less than 200 nm displayed lower cell proliferation, compared to free hEGF, but larger particles showed increased cell proliferation. This is in agreement with previous studies showing accumulation of activated-EGFRs in early endosomes triggers apoptosis of A431 and HeLa cells. The confocal microscopy and co-localization fluorescence staining showed the 500 and 1000 nm hEGF-conjs exclusively remained on the cell surface, probably enabling them to activate EGF receptors for a longer time. Conversely, smaller particles were mostly inside the cells, indicating their rapid endocytosis. Similarly, A431 cells treated with 20 nm hEGF-conj, endocytosed the particles and experienced decreased cell proliferation, while the 500 and 1000 nm hEGF-conjs were not internalized, and induced partial cell proliferation. Moreover, we showed multivalency of hEGF-conjs is not the cause of enhanced cell proliferation by large particles, as the degree of EGFR phosphorylation by free EGF was higher, compared to hEGF-conjs. Our results suggest the potential of micron-sized particles as a carrier for hEGF to enhance cell proliferation, which could be explored as a promising approach for topical application of growth factors for accelerating wound healing.
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Affiliation(s)
- Setayesh Yasami-Khiabani
- Department of Biomedical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran, Iran.
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2
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Sahinturk V, Kacar S, Sahin E, Aykanat NEB. Investigation of endoplasmic reticulum stress and sonic hedgehog pathway in diabetic liver injury in mice. Life Sci 2020; 246:117416. [PMID: 32035927 DOI: 10.1016/j.lfs.2020.117416] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/31/2019] [Accepted: 02/05/2020] [Indexed: 12/16/2022]
Abstract
AIMS Diabetes is a common metabolic disease which damages many organs including the liver and causes endoplasmic reticulum (ER) stress, which originates from non-folded proteins. Sonic hedgehog (Shh) pathway plays a role in liver regeneration and repair. To our knowledge, there is no study showing the relation between ER stress and Shh pathway in the liver in diabetes. Thus, the aim of this study was to investigate the interaction between ER stress and Shh pathway in the liver of diabetic mice. MAIN METHODS Six groups of male mice were formed as control, diabetes (streptozotocine-treated), Shh activator (SAG-treated), Shh inhibitor (SANT1-treated), diabetes + SAG and diabetes + SANT1. At the end of the experiment, mice were weighed, anaesthetized and euthanized. Blood samples were collected, livers were excised and weighed. Thereafter, blood glucose, serum ALT and AST levels, TOS and TAC levels in liver tissue were measured. ER stress marker (GRP78) and Shh pathway molecules (Gli1 and Smo) were evaluated by immunohistochemistry, H-score and western blot analyses. Besides, histopathological examination was performed. KEY FINDINGS Results showed that GRP78, Gli1 and Smo were increased in liver due to Type 1 diabetes. The SAG agent decreased GRP78 and increased Gli1 and Smo, leading to liver repair, while the inhibitor SANT1 increased GRP78 and decreased Gli1and Smo, causing progression of the liver stress induced by diabetes. SIGNIFICANCE In conclusion, the Shh pathway is related to ER stress and may provide a new strategy for its treatment, especially liver stress induced by diabetes.
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Affiliation(s)
- Varol Sahinturk
- Ekisehir Osmangazi University, Faculty of Medicine, Department of Histology and Embryology, Eskisehir, Turkey.
| | - Sedat Kacar
- Ekisehir Osmangazi University, Faculty of Medicine, Department of Histology and Embryology, Eskisehir, Turkey
| | - Erhan Sahin
- Ekisehir Osmangazi University, Faculty of Medicine, Department of Histology and Embryology, Eskisehir, Turkey
| | - Nuriye Ezgi Bektur Aykanat
- Ekisehir Osmangazi University, Faculty of Medicine, Department of Histology and Embryology, Eskisehir, Turkey
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3
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Hayes AJ, Melrose J. Glycosaminoglycan and Proteoglycan Biotherapeutics in Articular Cartilage Protection and Repair Strategies: Novel Approaches to Visco‐supplementation in Orthobiologics. ADVANCED THERAPEUTICS 2019. [DOI: 10.1002/adtp.201900034] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Anthony J. Hayes
- Bioimaging Research HubCardiff School of BiosciencesCardiff University Cardiff CF10 3AX Wales UK
| | - James Melrose
- Graduate School of Biomedical EngineeringUNSW Sydney Sydney NSW 2052 Australia
- Raymond Purves Bone and Joint Research LaboratoriesKolling Institute of Medical ResearchRoyal North Shore Hospital and The Faculty of Medicine and HealthUniversity of Sydney St. Leonards NSW 2065 Australia
- Sydney Medical SchoolNorthernRoyal North Shore HospitalSydney University St. Leonards NSW 2065 Australia
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Arsiwala A, Castro A, Frey S, Stathos M, Kane RS. Designing Multivalent Ligands to Control Biological Interactions: From Vaccines and Cellular Effectors to Targeted Drug Delivery. Chem Asian J 2019; 14:244-255. [DOI: 10.1002/asia.201801677] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Indexed: 01/02/2023]
Affiliation(s)
- Ammar Arsiwala
- School of Chemical and Biomolecular Engineering; Georgia Institute of Technology; Atlanta Georgia- 30332 USA
| | - Ana Castro
- School of Chemical and Biomolecular Engineering; Georgia Institute of Technology; Atlanta Georgia- 30332 USA
| | - Steven Frey
- School of Chemical and Biomolecular Engineering; Georgia Institute of Technology; Atlanta Georgia- 30332 USA
| | - Mark Stathos
- School of Chemical and Biomolecular Engineering; Georgia Institute of Technology; Atlanta Georgia- 30332 USA
| | - Ravi S. Kane
- School of Chemical and Biomolecular Engineering; Georgia Institute of Technology; Atlanta Georgia- 30332 USA
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Gong P, Li M, Zou C, Tian Q, Xu Z. Tissue Plasminogen Activator Causes Brain Microvascular Endothelial Cell Injury After Oxygen Glucose Deprivation by Inhibiting Sonic Hedgehog Signaling. Neurochem Res 2018; 44:441-449. [PMID: 30552546 PMCID: PMC6394519 DOI: 10.1007/s11064-018-2697-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Revised: 11/22/2018] [Accepted: 12/10/2018] [Indexed: 11/29/2022]
Abstract
The thrombolytic activity of tissue plasminogen activator (tPA) has undisputed benefits. However, the documented neurotoxicity of tPA raises important issues. Currently, common treatments for stroke might not be optimum if exogenous tPA can pass through the blood–brain barrier and enter the brain, thus adding to the deleterious effects of tPA within the cerebral parenchyma. Here, we determined whether tPA could damage brain microvascular endothelial cells (BMECs) during cerebral ischemia. We showed that treatment of BMECs with tPA decreased trans-endothelial electrical resistance and cell proliferation, and blocked the cell cycle at the G0–G1 phase. In addition, the Sonic hedgehog (Shh) signaling pathway was involved in tPA-induced BMECs dysfunction. However, tPA-enhanced oxygen glucose deprivation-induced BMECs dysfunction was eliminated by Shh administration and the effects could be reversed by Shh inhibitors. Taken together, these results demonstrate that tPA administration might result in damage to the endothelial barrier owing to blocked Shh signaling pathway.
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Affiliation(s)
- Pian Gong
- Department of Neurosurgery, Renmin Hospital of Wuhan University, No. 9 Zhangzhidong Road, Wuchang District, Wuhan, 430072, Hubei Province, China
| | - Mingchang Li
- Department of Neurosurgery, Renmin Hospital of Wuhan University, No. 9 Zhangzhidong Road, Wuchang District, Wuhan, 430072, Hubei Province, China.
| | - Changlin Zou
- Department of Neurosurgery, Renmin Hospital of Wuhan University, No. 9 Zhangzhidong Road, Wuchang District, Wuhan, 430072, Hubei Province, China
| | - Qi Tian
- Department of Neurosurgery, Renmin Hospital of Wuhan University, No. 9 Zhangzhidong Road, Wuchang District, Wuhan, 430072, Hubei Province, China
| | - Zhou Xu
- Department of Neurosurgery, Renmin Hospital of Wuhan University, No. 9 Zhangzhidong Road, Wuchang District, Wuhan, 430072, Hubei Province, China
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Salybekov AA, Salybekova AK, Pola R, Asahara T. Sonic Hedgehog Signaling Pathway in Endothelial Progenitor Cell Biology for Vascular Medicine. Int J Mol Sci 2018; 19:E3040. [PMID: 30301174 PMCID: PMC6213474 DOI: 10.3390/ijms19103040] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2018] [Revised: 09/28/2018] [Accepted: 10/01/2018] [Indexed: 01/08/2023] Open
Abstract
The Hedgehog (HH) signaling pathway plays an important role in embryonic and postnatal vascular development and in maintaining the homeostasis of organs. Under physiological conditions, Sonic Hedgehog (SHH), a secreted protein belonging to the HH family, regulates endothelial cell growth, promotes cell migration and stimulates the formation of new blood vessels. The present review highlights recent advances made in the field of SHH signaling in endothelial progenitor cells (EPCs). The canonical and non-canonical SHH signaling pathways in EPCs and endothelial cells (ECs) related to homeostasis, SHH signal transmission by extracellular vesicles (EVs) or exosomes containing single-strand non-coding miRNAs and impaired SHH signaling in cardiovascular diseases are discussed. As a promising therapeutic tool, the possibility of using the SHH signaling pathway for the activation of EPCs in patients suffering from cardiovascular diseases is further explored.
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Affiliation(s)
- Amankeldi A Salybekov
- Department of Regenerative Medicine Science, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa 2591193, Japan.
| | - Ainur K Salybekova
- Department of Regenerative Medicine Science, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa 2591193, Japan.
| | - Roberto Pola
- Department of Medicine, Fondazione Policlinico Universitario A. Gemelli IRCCS, Università Cattolica del Sacro Cuore, Rome 00168, Italy.
| | - Takayuki Asahara
- Department of Regenerative Medicine Science, Tokai University School of Medicine, 143 Shimokasuya, Isehara, Kanagawa 2591193, Japan.
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Kim YS, Sung DK, Kong WH, Kim H, Hahn SK. Synergistic effects of hyaluronate - epidermal growth factor conjugate patch on chronic wound healing. Biomater Sci 2018; 6:1020-1030. [PMID: 29616250 DOI: 10.1039/c8bm00079d] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The proteolytic microenvironment in the wound area reduces the stability and the half-life of growth factors in vivo, making difficult the topical delivery of growth factors. Here, epidermal growth factor (EGF) was conjugated to hyaluronate (HA) to improve the long-term stability against enzymatic degradation and the therapeutic effect by enhancing the biological interaction with HA receptors on skin cells. After the synthesis of HA-EGF conjugates, they were incorporated into a patch-type formulation for the facile topical application and sustained release of EGF. According to ELISA, the HA-EGF conjugates showed a long-term stability compared with native EGF. Furthermore, HA-EGF conjugates appeared to interact with skin cells through two types of HA and EGF receptors, resulting in a synergistically improved healing effect. Taken together, we could confirm the feasibility of HA-EGF conjugates for the transdermal treatment of chronic wounds.
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Affiliation(s)
- Yun Seop Kim
- Department of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongamro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea.
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8
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Zbinden A, Browne S, Altiok EI, Svedlund FL, Jackson WM, Healy KE. Multivalent conjugates of basic fibroblast growth factor enhance in vitro proliferation and migration of endothelial cells. Biomater Sci 2018; 6:1076-1083. [PMID: 29595848 PMCID: PMC5930118 DOI: 10.1039/c7bm01052d] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Growth factors hold great promise for regenerative therapies. However, their clinical use has been halted by poor efficacy and rapid clearance from tissue, necessitating the delivery of extremely high doses to achieve clinical effectiveness which has raised safety concerns. Thus, strategies to either enhance growth factor activity at low doses or to increase their residence time within target tissues are necessary for clinical success. In this study, we generated multivalent conjugates (MVCs) of basic fibroblast growth factor (bFGF), a key growth factor involved in angiogenesis and wound healing, to hyaluronic acid (HyA) polymer chains. Multivalent bFGF conjugates (mvbFGF) were fabricated with minimal non-specific interaction observed between bFGF and the HyA chain. The hydrodynamic radii of mvbFGF ranged from ∼50 to ∼75 nm for conjugation ratios of bFGF to HyA chains at low (10 : 1) and high (30 : 1) feed ratios, respectively. The mvbFGF demonstrated enhanced bioactivity compared to unconjugated bFGF in assays of cell proliferation and migration, processes critical to angiogenesis and tissue regeneration. The 30 : 1 mvbFGF outperformed the 10 : 1 conjugate, which could be due to either FGF receptor clustering or interference with receptor mediated internalization and signal deactivation. This study simultaneously investigated the role of both protein to polymer ratio and multivalent conjugate size on their bioactivity, and determined that increasing the protein-to-polymer ratio and conjugate size resulted in greater cell bioactivity.
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Affiliation(s)
- Aline Zbinden
- Department of Bioengineering and California Institute for Quantitative Biosciences (QB3), University of California at Berkeley, Berkeley, California 94720, USA.
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Holstlaw TA, Mahomed M, Brier LW, Young DM, Boudreau NJ, Jackson WM. Biopolymer Molecular Weight Can Modulate the Wound Healing Efficacy of Multivalent Sonic Hedgehog-Hyaluronic Acid Conjugates. Biomacromolecules 2017; 18:2350-2359. [PMID: 28679037 DOI: 10.1021/acs.biomac.7b00553] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
There is a clinical need for new therapeutics to improve healing of chronic impaired wounds. Thus, we investigated how biopolymer conjugation could be used to improve the wound healing performance of a key growth factor for tissue regeneration: Sonic hedgehog (Shh). We generated two multivalent Shh conjugates (mvShh) using hyaluronic acid with two different MWs, which exhibited equivalent potency and proteolytic protection in vitro. Using db/db diabetic mice, we showed that mvShh made with smaller HyA MW resulted in more rapid and robust neovascularization compared to mvShh made with larger MW HyA. Further, smaller mvShh conjugates resulted in faster wound resolution compared to the unconjugated Shh. This study is the first to show how the wound healing efficacy of multivalent protein-polymer conjugates is sensitive to the polymer MW, and our findings suggest that this parameter could be used to enhance the efficacy of growth factor conjugates.
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Affiliation(s)
| | | | - Livia W Brier
- Valitor, Inc. Berkeley, California 94710, United States
| | - David M Young
- Department of Surgery, University of California San Francisco , San Francisco, California 94110, United States
| | - Nancy J Boudreau
- Department of Surgery, University of California San Francisco , San Francisco, California 94110, United States
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10
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Svedlund FL, Altiok EI, Healy KE. Branching Analysis of Multivalent Conjugates Using Size Exclusion Chromatography-Multiangle Light Scattering. Biomacromolecules 2016; 17:3162-3171. [PMID: 27548567 DOI: 10.1021/acs.biomac.6b00785] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Multivalent conjugates (MVCs) (conjugation of multiple proteins to a linear polymer chain) are powerful for improving the bioactivity and pharmacokinetics of a bioactive molecule. Since this effect is highly dependent upon the valency of the conjugated proteins, it is imperative to have a technique for analysis of the conjugation ratio. Studies of MVCs have used size exclusion chromatography-multiangle light scattering (SEC-MALS), which allows for the separate and individual analysis of the protein and biopolymer components based on their specific refractive index increment and UV extinction coefficient constants to determine the number of proteins bound per biopolymer molecule. In this work, we have applied traditional branching analysis to the SEC-MALS data, with the primary assumption that the polymer backbone can be used as the linear counterpart. We demonstrated good agreement between the branching values and the valency determined by traditional analysis, demonstrating that branching analysis can be used as an alternative technique to approximate the valency of MVCs. The branching analysis method also provides a more complete picture of the distribution of the measured values, provides important branching information about the molecules, and lowers the cost and complexity of the characterization. However, since MVC molecules are both conjugate molecules and branched molecules, the most powerful approach to their characterization would be to use both traditional multivalent conjugate analysis and branching analysis in conjunction.
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Affiliation(s)
- Felicia L Svedlund
- Department of Materials Science and Engineering and §Department of Bioengineering, University of California at Berkeley , Berkeley, California 94720, United States
| | - Eda I Altiok
- Department of Materials Science and Engineering and §Department of Bioengineering, University of California at Berkeley , Berkeley, California 94720, United States
| | - Kevin E Healy
- Department of Materials Science and Engineering and §Department of Bioengineering, University of California at Berkeley , Berkeley, California 94720, United States
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Altiok EI, Browne S, Khuc E, Moran EP, Qiu F, Zhou K, Santiago-Ortiz JL, Ma JX, Chan MF, Healy KE. sFlt Multivalent Conjugates Inhibit Angiogenesis and Improve Half-Life In Vivo. PLoS One 2016; 11:e0155990. [PMID: 27257918 PMCID: PMC4892585 DOI: 10.1371/journal.pone.0155990] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 05/06/2016] [Indexed: 11/30/2022] Open
Abstract
Current anti-VEGF drugs for patients with diabetic retinopathy suffer from short residence time in the vitreous of the eye. In order to maintain biologically effective doses of drug for inhibiting retinal neovascularization, patients are required to receive regular monthly injections of drug, which often results in low patient compliance and progression of the disease. To improve the intravitreal residence time of anti-VEGF drugs, we have synthesized multivalent bioconjugates of an anti-VEGF protein, soluble fms-like tyrosine kinase-1 (sFlt) that is covalently grafted to chains of hyaluronic acid (HyA), conjugates that are termed mvsFlt. Using a mouse corneal angiogenesis assay, we demonstrate that covalent conjugation to HyA chains does not decrease the bioactivity of sFlt and that mvsFlt is equivalent to sFlt at inhibiting corneal angiogenesis. In a rat vitreous model, we observed that mvsFlt had significantly increased intravitreal residence time compared to the unconjugated sFlt after 2 days. The calculated intravitreal half-lives for sFlt and mvsFlt were 3.3 and 35 hours, respectively. Furthermore, we show that mvsFlt is more effective than the unconjugated form at inhibiting retinal neovascularization in an oxygen-induced retinopathy model, an effect that is most likely due to the longer half-life of mvsFlt in the vitreous. Taken together, our results indicate that conjugation of sFlt to HyA does not affect its affinity for VEGF and this conjugation significantly improves drug half-life. These in vivo results suggest that our strategy of multivalent conjugation could substantially improve upon drug half-life, and thus the efficacy of currently available drugs that are used in diseases such as diabetic retinopathy, thereby improving patient quality of life.
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Affiliation(s)
- Eda I. Altiok
- Department of Bioengineering, University of California, Berkeley, California, United States of America
| | - Shane Browne
- Department of Bioengineering, University of California, Berkeley, California, United States of America
- Centre for Research in Medical Devices (CÚRAM), National University of Ireland Galway, Galway, Ireland
| | - Emily Khuc
- Department of Ophthalmology, University of California at San Francisco, San Francisco, California, United States of America
| | - Elizabeth P. Moran
- Department of Physiology, Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Fangfang Qiu
- Department of Physiology, Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Kelu Zhou
- Department of Physiology, Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Jorge L. Santiago-Ortiz
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California, United States of America
| | - Jian-xing Ma
- Department of Physiology, Harold Hamm Diabetes Center, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, United States of America
| | - Matilda F. Chan
- Department of Ophthalmology, University of California at San Francisco, San Francisco, California, United States of America
| | - Kevin E. Healy
- Department of Bioengineering, University of California, Berkeley, California, United States of America
- Department of Materials Science and Engineering, University of California, Berkeley, California, United States of America
- * E-mail:
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Multivalent hyaluronic acid bioconjugates improve sFlt-1 activity in vitro. Biomaterials 2016; 93:95-105. [PMID: 27086270 DOI: 10.1016/j.biomaterials.2016.03.017] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 03/07/2016] [Accepted: 03/10/2016] [Indexed: 11/24/2022]
Abstract
Anti-VEGF drugs that are used in conjunction with laser ablation to treat patients with diabetic retinopathy suffer from short half-lives in the vitreous of the eye resulting in the need for frequent intravitreal injections. To improve the intravitreal half-life of anti-VEGF drugs, such as the VEGF decoy receptor sFlt-1, we developed multivalent bioconjugates of sFlt-1 grafted to linear hyaluronic acid (HyA) chains termed mvsFlt. Using size exclusion chromatography with multiangle light scattering (SEC-MALS), SDS-PAGE, and dynamic light scattering (DLS), we characterized the mvsFlt with a focus on the molecular weight contribution of protein and HyA components to the overall bioconjugate size. We found that mvsFlt activity was independent of HyA conjugation using a sandwich ELISA and in vitro angiogenesis assays including cell survival, migration and tube formation. Using an in vitro model of the vitreous with crosslinked HyA gels, we demonstrated that larger mvsFlt bioconjugates showed slowed release and mobility in these hydrogels compared to low molecular weight mvsFlt and unconjugated sFlt-1. Finally, we used an enzyme specific to sFlt-1 to show that conjugation to HyA shields sFlt-1 from protein degradation. Taken together, our findings suggest that mvsFlt bioconjugates retain VEGF binding affinity, shield sFlt-1 from enzymatic degradation, and their movement in hydrogel networks (in vitro model of the vitreous) is controlled by both bioconjugate size and hydrogel network mesh size. These results suggest that a strategy of multivalent conjugation could substantially improve drug residence time in the eye and potentially improve therapeutics for the treatment of diabetic retinopathy.
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Ozdemir T, Fowler EW, Hao Y, Ravikrishnan A, Harrington DA, Witt RL, Farach-Carson MC, Pradhan-Bhatt S, Jia X. Biomaterials-based strategies for salivary gland tissue regeneration. Biomater Sci 2016; 4:592-604. [PMID: 26878077 DOI: 10.1039/c5bm00358j] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The salivary gland is a complex, secretory tissue that produces saliva and maintains oral homeostasis. Radiation induced salivary gland atrophy, manifested as "dry mouth" or xerostomia, poses a significant clinical challenge. Tissue engineering recently has emerged as an alternative, long-term treatment strategy for xerostomia. In this review, we summarize recent efforts towards the development of functional and implantable salivary glands utilizing designed polymeric substrates or synthetic matrices/scaffolds. Although the in vitro engineering of a complex implantable salivary gland is technically challenging, opportunities exist for multidisciplinary teams to assemble implantable and secretory tissue modules by combining stem/progenitor cells found in the adult glands with biomimetic and cell-instructive materials.
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Affiliation(s)
- Tugba Ozdemir
- Department of Materials Science and Engineering, University of Delaware, Newark, DE 19716, USA
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Jiang XL, Chen T, Zhang X. Activation of sonic hedgehog signaling attenuates oxidized low-density lipoprotein-stimulated brain microvascular endothelial cells dysfunction in vitro. INTERNATIONAL JOURNAL OF CLINICAL AND EXPERIMENTAL PATHOLOGY 2015; 8:12820-12828. [PMID: 26722472 PMCID: PMC4680417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 09/28/2015] [Indexed: 06/05/2023]
Abstract
The study was performed to investigate the role of sonic hedgehog (SHH) in the oxidized low-density lipoprotein (oxLDL)-induced blood-brain barrier (BBB) disruption. The primary mouse brain microvascular endothelial cells (MBMECs) were exposed to oxLDL. The results indicated that treatment of MBMECs with oxLDL decreased the cell viability, and oxidative stress was involved in oxLDL-induce MBMECs dysfunction with increasing intracellular ROS and MDA formation as well as decreasing NO release and eNOS mRNA expression. In addition, SHH signaling components, such as SHH, Smo and Gli1, mRNA and protein levels were significantly decreased after incubation with increasing concentrations of oxLDL. Treatment with oxLDL alone or SHH loss-of-function significantly increased the permeability of MBMECs, and overexpression of SHH attenuated oxLDL-induced elevation of permeability in MBMECs. Furthermore, SHH gain-of-function could reverse oxLDL-induced apoptosis through inhibition caspase3 and caspase8 levels in MBMECs. Taken together, these results demonstrated that the suppression of SHH in MBMECs might contribute to the oxLDL-induced disruption of endothelial barrier. However, the overexpression of SHH could reverse oxLDL-induced endothelial cells dysfunction in vitro.
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Affiliation(s)
- Xiu-Long Jiang
- Department of Neurology, Provincial Clinic College of Fujian Medical University, Fujian Provincial Hospital Fuzhou 350001, China
| | - Ting Chen
- Department of Neurology, Provincial Clinic College of Fujian Medical University, Fujian Provincial Hospital Fuzhou 350001, China
| | - Xu Zhang
- Department of Neurology, Provincial Clinic College of Fujian Medical University, Fujian Provincial Hospital Fuzhou 350001, China
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