Levodopa-loaded nanoparticles for the treatment of Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder characterized by degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc) resulting in dopamine (DA) deficiency, which manifests itself in motor symptoms including tremors, rigidity and bradykinesia. Current PD treatments aim at symptom reduction through oral delivery of levodopa (L-DOPA), a precursor of DA. However, L-DOPA delivery to the brain is inefficient and increased dosages are required as the disease progresses, resulting in serious side effects like dyskinesias. To improve PD treatment efficacy and to reduce side effects, recent research focuses on the encapsulation of L-DOPA into polymeric- and lipid-based nanoparticles (NPs). These formulations can protect L-DOPA from systemic decarboxylation into DA and improve L-DOPA delivery to the central nervous system. Additionally, NPs can be modified with proteins, peptides and antibodies specifically targeting the blood-brain barrier (BBB), thereby reducing required dosages and free systemic DA. Alternative delivery approaches for NP-encapsulated L-DOPA include intravenous (IV) administration, transdermal delivery using adhesive patches and direct intranasal administration, facilitating increased therapeutic DA concentrations in the brain. This review provides an overview of the recent advances for NP-mediated L-DOPA delivery to the brain, and debates challenges and future perspectives on the field

A Chemically Defined Hydrogel for Human Liver Organoid Culture

End-stage liver diseases are an increasing health burden, and liver transplantations are currently the only curative treatment option. Due to a lack of donor livers, alternative treatments are urgently needed. Human liver organoids are very promising for regenerative medicine; however, organoids are currently cultured in Matrigel, which is extracted from the extracellular matrix of the Engelbreth-Holm-Swarm mouse sarcoma. Matrigel is poorly defined, suffers from high batch-to-batch variability and is of xenogeneic origin, which limits the clinical application of organoids. Here, a novel hydrogel based on polyisocyanopeptides (PIC) and laminin-111 is described for human liver organoid cultures. PIC is a synthetic polymer that can form a hydrogel with thermosensitive properties, making it easy to handle and very attractive for clinical applications. Organoids in an optimized PIC hydrogel proliferate at rates comparable to those observed with Matrigel; proliferation rates are stiffness-dependent, with lower stiffnesses being optimal for organoid proliferation. Moreover, organoids can be efficiently differentiated toward a hepatocyte-like phenotype with key liver functions. This proliferation and differentiation potential maintain over at least 14 passages. The results indicate that PIC is very promising for human liver organoid culture and has the potential to be used in a variety of clinical applications including cell therapy and tissue engineering

Bdnf gene is a downstream target of Nurr1 transcription factor in rat midbrain neurons in vitro

The transcription factor Nurr1 is essential for the generation of midbrain dopaminergic neurons (mDA). Only a few Nurr1-regulated genes have so far been identified and it remains unclear how Nurr1 influences the development and function of dopaminergic neurons. To identify novel Nurr1 target genes we have used genome-wide expression profiling in rat midbrain primary cultures, enriched in dopaminergic neurons, following up-regulation of Nurr1 expression by depolarization. In this study we demonstrate that following depolarization the hyperexpression of Nurr1 and the brain derived neurotrophic factor (BDNF) are phospholipase C- and protein kinase C-dependent. We show that Bdnf, which encodes a neurotrophin involved also in the phenotypic maturation of mDA neurons, is a novel Nurr1 target gene. By RNA interference experiments we show that a decreased Nurr1 expression is followed by tyrosine hydroxylase and BDNF mRNA and protein down-regulation. Reporter gene assay experiments performed on midbrain primary cultures using four Bdnf promoter constructs show that Bdnf is a direct target gene of Nurr1. Taken together, our findings suggest that Nurr1 might also influence the development and the function of midbrain dopaminergic neurons via direct regulation of Bdnf expression. © 2007 The Authors

Neural tube morphogenesis in synthetic 3D microenvironments

Three-dimensional organoid constructs serve as increasingly widespread in vitro models for development and disease modeling. Current approaches to recreate morphogenetic processes in vitro rely on poorly controllable and ill-defined matrices, thereby largely overlooking the contribution of biochemical and biophysical extracellular matrix (ECM) factors in promoting multicellular growth and reorganization. Here, we show how defined synthetic matrices can be used to explore the role of the ECM in the development of complex 3D neuroepithelial cysts that recapitulate key steps in early neurogenesis. We demonstrate how key ECM parameters are involved in specifying cytoskeleton-mediated symmetry-breaking events that ultimately lead to neural tube-like patterning along the dorsal-ventral (DV) axis. Such synthetic materials serve as valuable tools for studying the discrete action of extrinsic factors in organogenesis, and allow for the discovery of relationships between cytoskeletal mechanobiology and morphogenesis

Neural tube morphogenesis in synthetic 3D microenvironments

Three-dimensional organoid constructs serve as increasingly widespread in vitro models for development and disease modeling. Current approaches to recreate morphogenetic processes in vitro rely on poorly controllable and ill-defined matrices, thereby largely overlooking the contribution of biochemical and biophysical extracellular matrix (ECM) factors in promoting multicellular growth and reorganization. Here, we show how defined synthetic matrices can be used to explore the role of the ECM in the development of complex 3D neuroepithelial cysts that recapitulate key steps in early neurogenesis. We demonstrate how key ECM parameters are involved in specifying cytoskeleton-mediated symmetry-breaking events that ultimately lead to neural tube-like patterning along the dorsal-ventral (DV) axis. Such synthetic materials serve as valuable tools for studying the discrete action of extrinsic factors in organogenesis, and allow for the discovery of relationships between cytoskeletal mechanobiology and morphogenesis.status: publishe

Neural tube morphogenesis in synthetic 3D microenvironments

Three-dimensional organoid constructs serve as increasingly widespread in vitro models for development and disease modeling. Current approaches to recreate morphogenetic processes in vitro rely on poorly controllable and ill-defined matrices, thereby largely overlooking the contribution of biochemical and biophysical extracellular matrix (ECM) factors in promoting multicellular growth and reorganization. Here, we show how defined synthetic matrices can be used to explore the role of the ECM in the development of complex 3D neuroepithelial cysts that recapitulate key steps in early neurogenesis. We demonstrate how key ECM parameters are involved in specifying cytoskeleton-mediated symmetry-breaking events that ultimately lead to neural tube-like patterning along the dorsal-ventral (DV) axis. Such synthetic materials serve as valuable tools for studying the discrete action of extrinsic factors in organogenesis, and allow for the discovery of relationships between cytoskeletal mechanobiology and morphogenesis

Direct conversion of fibroblasts into functional astrocytes by defined transcription factors.

Direct cell reprogramming enables direct conversion of fibroblasts into functional neurons and oligodendrocytes using a minimal set of cell-lineage-specific transcription factors. This approach is rapid and simple, generating the cell types of interest in one step. However, it remains unknown whether this technology can be applied to convert fibroblasts into astrocytes, the third neural lineage. Astrocytes play crucial roles in neuronal homeostasis, and their dysfunctions contribute to the origin and progression of multiple human diseases. Herein, we carried out a screening using several transcription factors involved in defining the astroglial cell fate and identified NFIA, NFIB, and SOX9 to be sufficient to convert with high efficiency embryonic and postnatal mouse fibroblasts into astrocytes (iAstrocytes). We proved both by gene-expression profiling and functional tests that iAstrocytes are comparable to native brain astrocytes. This protocol can be then employed to generate functional iAstrocytes for a wide range of experimental applications

Multi-organ investigation in 16 CADASIL families from central Italy sharing the same R1006C mutation

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) may involve many target organs with relevant variability among affected individuals. We performed a multi-organ assessment tapping nervous system, skeletal muscle and cardiovascular system in thirty-nine individuals belonging to 16 families from Central Italy sharing the same R1006C CADASIL mutation. Stroke prevalence was larger in female patients (66.7%) than in males (23.8%); high levels of CKemia were quite frequent (21.6%) and were related to a myopathy without mitochondrial alterations; several individuals had atrial septal aneurysm (10.3%). No specific relationships between common cardiovascular risk factors and clinical manifestations were found. The present systematic study thus identified several gender-related, myopathic and cardiovascular peculiarities of R1006C mutation. This kind of comprehensive approach is necessary to define clinical course, prognosis and treatment options for a multi-organ disease such as CADASIL