The Role of Interstitial Fluid Pressure in Cerebral Porous Biomaterial Integration.

Recent advances in biomaterials offer new possibilities for brain tissue reconstruction. Biocompatibility, provision of cell adhesion motives and mechanical properties are among the present main design criteria. We here propose a radically new and potentially major element determining biointegration of porous biomaterials: the favorable effect of interstitial fluid pressure (IFP).

Design of an elastic porous injectable biomaterial for tissue regeneration and volume retention.

Soft tissue reconstruction currently relies on two main approaches, one involving the implantation of external biomaterials and the second one exploiting surgical autologous tissue displacement. While both methods have different advantages and disadvantages, successful long-term solutions for soft tissue repair are still limited. Specifically, volume retention over time and local tissue regeneration are the main challenges in the field.

An Injectable Meta-Biomaterial: From Design and Simulation to In Vivo Shaping and Tissue Induction.

A novel type of injectable biomaterial with an elastic softening transition is described. The material enables in vivo shaping, followed by induction of 3D stable vascularized tissue. The synthesis of the injectable meta-biomaterial is instructed by extensive numerical simulation as a suspension of irregularly fragmented, highly porous sponge-like microgels.

Neurothreads: Development of supportive carriers for mature dopaminergic neuron differentiation and implantation.

In this study we present the use of elastic macroporous cryogels for differentiation and transplantation of mature neurons. We develop a coating suitable for long-term neuronal culture, including stem cell differentiation, by covalent immobilization of neural adhesion proteins. In the context of cell therapy for Parkinson's disease, we show compatibility with established dopaminergic differentiation of both immortalized mesencephalic progenitors - LUHMES - and human embryonic stem cells (hESCs).

Injectable, scalable 3D tissue-engineered model of marrow hematopoiesis.

Modeling the interaction between the supportive stroma and the hematopoietic stem and progenitor cells (HSPC) is of high interest in the regeneration of the bone marrow niche in blood disorders. In this work, we present an injectable co-culture system to study this interaction in a coherent in vitro culture and in vivo transplantation model. We assemble a 3D hematopoietic niche in vitro by co-culture of supportive OP9 mesenchymal cells and HSPCs in porous, chemically defined collagen-coated carboxymethylcellulose microscaffolds (CCMs).

Regenerative potential of primary adult human neural stem cells on micropatterned bio-implants boosts motor recovery.

Background: The adult brain is unable to regenerate itself sufficiently after large injuries. Therefore, hopes rely on therapies using neural stem cell or biomaterial transplantation to sustain brain reconstruction. The aim of the present study was to evaluate the improvement in sensorimotor recovery brought about by human primary adult neural stem cells (hNSCs) in combination with bio-implants.

Detection of Alzheimer's disease amyloid-beta plaque deposition by deep brain impedance profiling.

Objective: Alzheimer disease (AD) is the most common form of neurodegenerative disease in elderly people. Toxic brain amyloid-beta (Aß) aggregates and ensuing cell death are believed to play a central role in the pathogenesis of the disease. In this study, we investigated if we could monitor the presence of these aggregates by performing in situ electrical impedance spectroscopy measurements in AD model mice brains.

A compressible scaffold for minimally invasive delivery of large intact neuronal networks.

Millimeter to centimeter-sized injectable neural scaffolds based on macroporous cryogels are presented. The polymer-scaffolds are made from alginate and carboxymethyl-cellulose by a novel simple one-pot cryosynthesis. They allow surgical sterility by means of autoclaving, and present native laminin as an attachment motive for neural adhesion and neurite development.

Investigation of the competition between cell/surface and cell/cell interactions during neuronal cell culture on a micro-engineered surface.

To investigate the respective roles of topography and cell/cell interactions in the development of a guided neuronal network on an engineered surface, micropatterned PDMS substrates were generated with different microgrooves geometry and investigated for the influence of cell density on neurite outgrowth and alignment. Through this systematic investigation, using a human neuronal stem cell line, the rules of neuronal network development and guiding could be learned. The results show that when cell density is increased the influence on neuritic outgrowth and alignment is very different for the various grooves geometries.

[Micro/nano-engineering to control growth of neuronal cells and tissue engineering applied to the central nervous system].

Central nervous system pathologies are often characterized by the loss of cell populations. A promising therapy now being developed consists in using bioactive materials, associating grafted cells to biopolymers which provide a scaffold for the in vitro building of new tissues, to be implanted in vivo. In the present article, the state of the art of this field, at crossroads between microtechnology and neuroscience, is described in detail; thereafter our own approach and results about interactions between adult human neural stem cells and microstructured polymers are summarized and discussed.

Elucidation of the role of carbon nanotube patterns on the development of cultured neuronal cells.

Carbon nanotubes (CNTs) promise various novel neural biomedical applications for interfacing neurons with electronic devices or to design appropriate biomaterials for tissue regeneration. In this study, we use a new methodology to pattern SiO(2) cell culture surfaces with double-walled carbon nanotubes (DWNTs). In contrast to homogeneous surfaces, patterned surfaces allow us to investigate new phenomena about the interactions between neural cells and CNTs.

Engineering of adult human neural stem cells differentiation through surface micropatterning.

Interaction between differentiating neural stem cells and the extracellular environment guides the establishment of cell polarity during nervous system development. Developing neurons read the physical properties of the local substrate in a contact-dependent manner and retrieve essential guidance cues. To restore damage brain area by tissue engineering, the biomaterial scaffold has to mimic this microenvironment to allow organized tissue regeneration.

Frustrated phagocytosis on micro-patterned immune complexes to characterize lysosome movements in live macrophages.

Lysosome mobilization is a key cellular process in phagocytes for bactericidal activities and trans-matrix migration. The molecular mechanisms that regulate lysosome mobilization are still poorly known. Lysosomes are hard to track as they move toward phagosomes throughout the cell volume.