Geometrically controlled liquefied capsules for modular tissue engineering strategies

A plethora of bioinspired cell-laden hydrogels are being explored as building blocks that once assembled are able to create complex and highly hierarchical structures recapitulating the heterogeneity of living tissues. Yet, the resulting 3D bioengineered systems still present key limitations, mainly related with limited diffusion of essential molecules for cell survival, which dictates the failure of most strategies upon implantation. To maximize the hierarchical complexity of bioengineered systems, while simultaneously fully addressing the exchange efficiency of biomolecules, the high-throughput fabrication of liquefied capsules is proposed using superhydrophobic-superhydrophilic microarrays as platforms to produce the initial structures with high fidelity of geometry and size. The liquefied capsules are composed by i) a permselective multilayered membrane; ii) surface-functionalized poly(ε-caprolactone) microparticles loaded into the liquefied core acting as cell adhesion sites; and iii) cells. It is demonstrated that besides the typical spherical liquefied capsules, it is also possible to obtain multi-shaped blocks with high geometrical precision and efficiency. Importantly, the internal gelation approach used to produce such blocks does not jeopardize cell viability, evidencing the mild conditions of the proposed cell encapsulation technique. The proposed system is intended to be used as hybrid devices implantable using minimally invasive procedures for multiple tissue engineering applications.publishe

Nanogrooved microdiscs for bottom-up modulation of osteogenic differentiation

Grooved topographical features have effectively modulated cell differentiation on two-dimensional substrates. To transpose patterning into a 3D environmment, nanogrooved microdiscs, "topodiscs", are produced as cell carriers for bottom-up cell-mediated assembly. While enhancing cell proliferation, topodiscs led to the formation of bone-like aggregates, even in culture medium lacking osteoinductive factors.publishe

Advanced Control over Cell-Material Interfaces

Cells in vivo sense and respond to signals from their environment (e.g., other cells and extracellular matrices) for their orchestrated behaviour and function.[...

Advance of Polymers Applied to Biomedical Applications: Cell Scaffolds

Since Langer’s seminal work, polymers have been on every corner of tissue engineering. The roles of bioresorbable polymers, as a scaffold, are not merely structural, providing three-dimensional (3D) homing sites to cells, but also functional at their interface with the cells. The polymeric scaffolds actively act as both biochemical and physical cues for cell behaviors, such as adhesion, growth, proliferation, and differentiation. Polymers and cells could interact further with each other mutually, sensing and responding to the signals from the partner. Technological advances in this direction, including chemical modification of polymer scaffolds, highly cytocompatible hybrid materials/composites, dynamic scaffolds, control of juxtacrine interactions, and 3D bioprinting and microfluidic devices, ensure the advances in polymers as cell scaffolds. The detection and characterization methods for cell-material interactions and cell behaviors have been greatly improved, and new characterization techniques have emerged. Recent years have witnessed a quantum leap of progress in tissue engineering and regenerative medicine, and this edited book illustrates some of the advances in polymers as cell scaffolds

Real-Time Monitoring of a Botulinum Neurotoxin Using All-Carbon Nanotube-Based Field-Effect Transistor Devices

The possibility of exposure to botulinum neurotoxin (BoNT), a powerful and potential bioterrorism agent, is considered to be ever increasing. The current gold-standard assay, live-mouse lethality, exhibits high sensitivity but has limitations including long assay times, whereas other assays evince rapidity but lack factors such as real-time monitoring or portability. In this study, we aimed to devise a novel detection system that could detect BoNT at below-nanomolar concentrations in the form of a stretchable biosensor. We used a field-effect transistor with a p-type channel and electrodes, along with a channel comprising aligned carbon nanotube layers to detect the type E light chain of BoNT (BoNT/E-Lc). The detection of BoNT/E-Lc entailed observing the cleavage of a unique peptide and the specific bonding between BoNT/E-Lc and antibody BoNT/E-Lc (Anti-BoNT/E-Lc). The unique peptide was cleaved by 60 pM BoNT/E-Lc; notably, 52 fM BoNT/E-Lc was detected within 1 min in the device with the antibody in the bent state. These results demonstrated that an all-carbon nanotube-based device (all-CNT-based device) could be produced without a complicated fabrication process and could be used as a biosensor with high sensitivity, suggesting its potential development as a wearable BoNT biosensor

In Vitro Studies on Therapeutic Effects of Cannabidiol in Neural Cells: Neurons, Glia, and Neural Stem Cells

(‒)-Cannabidiol (CBD) is one of the major phytocannabinoids extracted from the Cannabis genus. Its non-psychoactiveness and therapeutic potential, partly along with some anecdotal—if not scientific or clinical—evidence on the prevention and treatment of neurological diseases, have led researchers to investigate the biochemical actions of CBD on neural cells. This review summarizes the previously reported mechanistic studies of the CBD actions on primary neural cells at the in vitro cell-culture level. The neural cells are classified into neurons, microglia, astrocytes, oligodendrocytes, and neural stem cells, and the CBD effects on each cell type are described. After brief introduction on CBD and in vitro studies of CBD actions on neural cells, the neuroprotective capability of CBD on primary neurons with the suggested operating actions is discussed, followed by the reported CBD actions on glia and the CBD-induced regeneration from neural stem cells. A summary section gives a general overview of the biochemical actions of CBD on neural cells, with a future perspective. This review will provide a basic and fundamental, but crucial, insight on the mechanistic understanding of CBD actions on neural cells in the brain, at the molecular level, and the therapeutic potential of CBD in the prevention and treatment of neurological diseases, although to date, there seem to have been relatively limited research activities and reports on the cell culture-level, in vitro studies of CBD effects on primary neural cells