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Multiple therapies have been studied to ameliorate the neuroinhibitory cues present after traumatic injury to the central nervous system. Two previous in vitro studies have demonstrated the efficacy of the FDA-approved cardiovascular therapeutic, protamine (PRM), to overcome neuroinhibitory cues presented by chondroitin sulfates; however, the effect of a wide range of PRM concentrations on neuronal and glial cells has not been evaluated. In this study, we investigate the therapeutic efficacy of PRM with primary cortical neurons, hippocampal neurons, mixed glial cultures, and astrocyte cultures. We show the threshold for PRM toxicity to be at or above 10 µg/ml depending on the cell population, that 10 µg/ml PRM enables neurons to overcome the inhibitory cues presented by chondroitin sulfate type A, and that soluble PRM allows neurons to more effectively overcome inhibition compared to a PRM coating. We also assessed changes in gene expression of reactive astrocytes with soluble PRM and determined that PRM does not increase their neurotoxic phenotype and that PRM may reduce brevican production and serpin transcription in cortical and spinal cord astrocytes. This is the first study to thoroughly assess the toxicity threshold of PRM with neural cells and study astrocyte response after acute exposure to PRM in vitro.
RESUMO
SAR studies on a series of thiophene amide derivatives provided CB(2) receptor agonists. The activity of the compounds was characterized by radioligand binding determination, multiple functional assays, ADME, and pharmacokinetic studies. A representative compound with selectivity for CB(2) over CB(1) effectively produced analgesia in behavioral models of neuropathic, inflammatory, and postsurgical pain. Control experiments using a CB(2) antagonist demonstrated the efficacy in the pain models resulted from CB(2) agonism.
Assuntos
Amidas/síntese química , Analgésicos/síntese química , Hiperalgesia/tratamento farmacológico , Neuralgia/tratamento farmacológico , Receptor CB2 de Canabinoide/agonistas , Tiofenos/síntese química , Amidas/farmacocinética , Amidas/farmacologia , Analgésicos/farmacocinética , Analgésicos/farmacologia , Animais , Disponibilidade Biológica , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Humanos , Hiperalgesia/metabolismo , Neuralgia/metabolismo , Ensaio Radioligante , Ratos , Ratos Sprague-Dawley , Receptor CB1 de Canabinoide/metabolismo , Receptor CB2 de Canabinoide/metabolismo , Relação Estrutura-Atividade , Tiofenos/farmacocinética , Tiofenos/farmacologiaRESUMO
Electrospun fibers are versatile biomaterial platforms with great potential to support regeneration. Electrospun fiber characteristics such as fiber diameter, degree of alignment, rate of degradation, and surface chemistry enable the creation of unique, tunable scaffolds for various drug or gene delivery applications. The delivery of genetic material and genome editing tools via viral and non-viral vectors are approaches to control cellular protein production. However, immunogenicity, off-target effects, and low delivery efficiencies slow the progression of gene delivery strategies to clinical settings. The delivery of genetic material from electrospun fibers overcomes such limitations by allowing for localized, tunable delivery of genetic material. However, the process of electrospinning is harsh, and care must be taken to retain genetic material bioactivity. This review presents an up-to-date summary of strategies to incorporate genetic material onto or within electrospun fiber platforms to improve delivery efficiency and enhance the regenerative potential of electrospun fibers for various tissue engineering applications.
Assuntos
Nanofibras , Materiais Biocompatíveis , Edição de Genes , Técnicas de Transferência de Genes , Humanos , Engenharia Tecidual , Alicerces TeciduaisRESUMO
Objective.Nerve guidance scaffolds containing anisotropic architectures provide topographical cues to direct regenerating axons through an injury site to reconnect the proximal and distal end of an injured nerve or spinal cord. Previousin vitrocultures of individual neurons revealed that fiber characteristics such as fiber diameter and inter-fiber spacing alter neurite morphological features, such as total neurite length, the longest single neurite, branching density, and the number of primary neurites. However, the relationships amongst these four neurite morphological features have never been studied on fibrous topographies using multivariate analysis.Approach.In this study, we cultured dissociated dorsal root ganglia on aligned, fibrous scaffolds and flat, isotropic films and evaluated the univariate and multivariate differences amongst these four neurite morphological features.Main results.Univariate analysis showed that fibrous scaffolds increase the length of the longest neurite and decrease branching density compared to film controls. Further, multivariate analysis revealed that, regardless of scaffold type, overall neurite length increases due to a compromise between the longest extending neurite, branching density, and the number of primary neurites. Additionally, multivariate analysis indicated that neurite branching is more independent of the other neurite features when neurons were cultured on films but that branching is strongly related to the other neurite features when cultured on fibers.Significance.These findings are significant as they are the first evidence that aligned topographies affect the relationships between neurite morphological features. This study provides a foundation for analyzing how individual neurite morphology may relate to neural regeneration on a macroscopic scale and provide information that may be used to optimize nerve guidance scaffolds.
Assuntos
Gânglios Espinais , Neuritos , Células Cultivadas , Gânglios Espinais/fisiologia , Análise Multivariada , Regeneração Nervosa/fisiologia , Neuritos/fisiologia , Neurônios/fisiologia , Poliésteres , Alicerces TeciduaisRESUMO
Synthesis and biological evaluation of a novel class of substituted N-benzyl-1-(2,3-dichlorophenyl)-1H-tetrazol-5-amine derivatives resulted in the identification of potent P2X(7) antagonists. These compounds were assayed for activity at both the human and rat P2X(7) receptors. On the benzyl moiety, a variety of functional groups were tolerated, including both electron-withdrawing and electron-donating substituents. Ortho-substitution on the benzyl group provided the greatest potency. The ortho-substituted analogs showed approximately 2.5-fold greater potency at human compared to rat P2X(7) receptors. Compounds 12 and 38 displayed hP2X(7)pIC(50)s>7.8 with less than 2-fold difference in potency at the rP2X(7).
Assuntos
Aminas/síntese química , Antagonistas do Receptor Purinérgico P2X/síntese química , Antagonistas do Receptor Purinérgico P2X/farmacologia , Tetrazóis/síntese química , Aminas/química , Aminas/farmacologia , Animais , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Ligação Proteica/efeitos dos fármacos , Antagonistas do Receptor Purinérgico P2X/química , Ratos , Relação Estrutura-Atividade , Tetrazóis/química , Tetrazóis/farmacologiaRESUMO
Neurological and functional recovery is limited following central nervous system injury and severe injury to the peripheral nervous system. Extracellular matrix (ECM)-mimetic hydrogels are of particular interest as regenerative scaffolds for the injured nervous system as they provide 3D bioactive interfaces that modulate cellular response to the injury environment and provide naturally degradable scaffolding for effective tissue remodeling. In this review, three unique ECM-mimetic hydrogels used in models of neural injury are reviewed: fibrin hydrogels, which rely on a naturally occurring enzymatic gelation, hyaluronic acid hydrogels, which require chemical modification prior to chemical crosslinking, and elastin-like polypeptide (ELP) hydrogels, which exhibit a temperature-sensitive gelation. The hydrogels are reviewed by summarizing their unique biological properties, their use as drug depots, and their combination with other biomaterials, such as electrospun fibers and nanoparticles. This review is the first to focus on these three ECM-mimetic hydrogels for their use in neural tissue engineering. Additionally, this is the first review to summarize the use of ELP hydrogels for nervous system applications. ECM-mimetic hydrogels have shown great promise in preclinical models of neural injury and future advancements in their design and use can likely lead to viable treatments for patients with neural injury.
Assuntos
Elastina , Ácido Hialurônico , Matriz Extracelular , Fibrina , Humanos , Hidrogéis , Peptídeos , Engenharia TecidualRESUMO
Electrospinning is a fabrication technique used to produce nano- or micro- diameter fibers to generate biocompatible, biodegradable scaffolds for tissue engineering applications. Electrospun fiber scaffolds are advantageous for neural regeneration because they mimic the structure of the nervous system extracellular matrix and provide contact guidance for regenerating axons. Glia are non-neuronal regulatory cells that maintain homeostasis in the healthy nervous system and regulate regeneration in the injured nervous system. Electrospun fiber scaffolds offer a wide range of characteristics, such as fiber alignment, diameter, surface nanotopography, and surface chemistry that can be engineered to achieve a desired glial cell response to injury. Further, electrospun fibers can be loaded with drugs, nucleic acids, or proteins to provide the local, sustained release of such therapeutics to alter glial cell phenotype to better support regeneration. This review provides the first comprehensive overview of how electrospun fiber alignment, diameter, surface nanotopography, surface functionalization, and therapeutic delivery affect Schwann cells in the peripheral nervous system and astrocytes, oligodendrocytes, and microglia in the central nervous system both in vitro and in vivo. The information presented can be used to design and optimize electrospun fiber scaffolds to target glial cell response to mitigate nervous system injury and improve regeneration.
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N'-aryl acyl hydrazides were identified as P2X7 receptor antagonists. Structure-activity relationship (SAR) studies evaluated functional activity by monitoring calcium flux inhibition in cell lines expressing recombinant human and rat P2X7 receptors. Selected analogs were assayed in vitro for their capacity to inhibit release of cytokine IL-1beta. Compounds with potent antagonist function were evaluated in vivo using the zymosan-induced peritonitis model. A representative compound effectively attenuated mechanical allodynia in a rat model of neuropathic pain.
Assuntos
Analgésicos/síntese química , Hidrazinas/síntese química , Antagonistas do Receptor Purinérgico P2 , Analgésicos/química , Analgésicos/farmacologia , Animais , Cálcio/metabolismo , Linhagem Celular , Humanos , Hidrazinas/química , Hidrazinas/farmacologia , Interleucina-1beta/antagonistas & inibidores , Interleucina-1beta/metabolismo , Isoquinolinas/síntese química , Isoquinolinas/química , Isoquinolinas/farmacologia , Dor/tratamento farmacológico , Medição da Dor , Doenças do Sistema Nervoso Periférico/tratamento farmacológico , Cavidade Peritoneal , Peritonite/metabolismo , Peritonite/prevenção & controle , Quinolinas/síntese química , Quinolinas/química , Quinolinas/farmacologia , Ratos , Receptores Purinérgicos P2X7 , Proteínas Recombinantes/antagonistas & inibidores , Relação Estrutura-AtividadeRESUMO
1-Benzyl-5-aryltetrazoles were discovered to be novel antagonists for the P2X(7) receptor. Structure-activity relationship (SAR) studies were conducted around both the benzyl and phenyl moieties. In addition, the importance of the regiochemical substitution on the tetrazole was examined. Compounds were evaluated for activity to inhibit calcium flux in both human and rat recombinant P2X(7) cell lines using fluorometric imaging plate reader technology. Analogues were also assayed for their ability to inhibit IL-1beta release and to inhibit P2X(7)-mediated pore formation in human THP-1 cells. Compound 15d was advanced to efficacy studies in a model of neuropathic pain where significant reversal of mechanical allodynia was observed at doses that did not affect motor coordination.