A combined experimental and computational framework to evaluate the behavior of therapeutic cells for peripheral nerve regeneration.

Recent studies have explored the potential of tissue-mimetic scaffolds in encouraging nerve regeneration. One of the major determinants of the regenerative success of cellular nerve repair constructs (NRCs) is the local microenvironment, particularly native low oxygen conditions which can affect implanted cell survival and functional performance. In vivo, cells reside in a range of environmental conditions due to the spatial gradients of nutrient concentrations that are established. Here we evaluate in vitro the differences in cellular behavior that such conditions induce, including key biological features such as oxygen metabolism, glucose consumption, cell death, and vascular endothelial growth factor secretion. Experimental measurements are used to devise and parameterize a mathematical model that describes the behavior of the cells. The proposed model effectively describes the interactions between cells and their microenvironment and could in the future be extended, allowing researchers to compare the behavior of different therapeutic cells. Such a combinatorial approach could be used to accelerate the clinical translation of NRCs by identifying which critical design features should be optimized when fabricating engineered nerve repair conduits.

Naringin nanoparticles against neurodegenerative processes: A preliminary work.

It is well established that during Alzheimer disease (AD), gradual loss of neuronal networks occurs in the brain, consequently, affecting cognition and memory tasks of the patients. Among other causative factors, oxidative stress induces changes that are eventually accompanied by an irreversible disruption of synaptic connectivity and death of neurons. Moreover, aging and oxidative stress cause alterations to the blood brain barrier, leading to increased permeability, which are thought to further aggravate the underlying pathology. Up to date, no effective treatment is available to Alzheimer's disease patients. Lately, scientific efforts are focusing on exploiting the antioxidant properties that natural polyphenol agents such as flavonoids possess and their potential beneficial effect against neurodegenerative diseases. For that reason, the current investigation, aims at developing more effective flavonoid agents by encapsulating naringin into modified PEG 3000 Silica nanoparticles before its use at cellular level. Overall, our findings suggest an enhanced protective capacity of naringin pegylated nanoparticles against Aß amyloid linked oxidative stress mediated neurodegeneration in primary rat neuronal and glial hippocampal cultures for a certain incubation period. The functional biological reactivities of the novel flavonoid nanoparticles were in line with their physicochemical features and reflect the a) differential nature of the structural assemblies of the new nanoparticles, thereby distinguishing them from other polymeric and liposomal drug carriers, and b) significance and impact of PEG chemistry in the synthetic assembly of the nanocarriers. The ability of the employed nanoparticles to entrap a relatively high dose of otherwise insoluble drugs and their biological activity highlight their potential as brain targeting therapeutics.

Chitosan encapsulation of essential oil "cocktails" with well-defined binary Zn(II)-Schiff base species targeting antibacterial medicinal nanotechnology.

The advent of biodegradable nanomaterials with enhanced antibacterial activity stands as a challenge to the global research community. In an attempt to pursue the development of novel antibacterial medicinal nanotechnology, we herein a) synthesized ionic-gelated chitosan nanoparticles, b) compared and evaluated the antibacterial activity of essential oils extracted from nine different herbs (Greek origin) and their combinations with a well-defined antibacterial Zn(II)-Schiff base compound, and c) encapsulated the most effective hybrid combination of Zn(II)-essential oils inside the chitosan matrix, thereby targeting well-formulated nanoparticles of distinct biological impact. The empty and loaded chitosan nanoparticles were physicochemically characterized by FT-IR, Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), with the entrapment and drug release studies being conducted through UV-Visible and atomic absorption techniques. The antimicrobial properties of the novel hybrid materials were demonstrated against Gram positive (S. aureus, B. subtilis, and B. cereus) and Gram negative (E. coli and X. campestris) bacteria using modified agar diffusion methods. The collective physicochemical profile of the hybrid Zn(II)-essential oil cocktails, formulated so as to achieve optimal activity when loaded to chitosan nanoparticles, signifies the importance of design in the development of efficient nanomedicinal pharmaceuticals a) based on both natural products and biogenic metal ionic cofactors, and b) targeting bacterial infections and drug resistance.