PLASTAMINATION: Outcomes on the Central Nervous System and Reproduction.

BACKGROUND: Environmental exposures to non-biodegradable and biodegradable plastics are unavoidable. Microplastics (MPs) and nanoplastics (NPs) from the manufacturing of plastics (primary sources) and the degradation of plastic waste (secondary sources) can enter the food chain directly or indirectly and, passing biological barriers, could target both the brain and the gonads. Hence, the worldwide diffusion of environmental plastic contamination (PLASTAMINATION) in daily life may represent a possible and potentially serious risk to human health. OBJECTIVE: This review provides an overview of the effects of non-biodegradable and the more recently introduced biodegradable MPs and NPs on the brain and brain-dependent reproductive functions, summarizing the molecular mechanisms and outcomes on nervous and reproductive organs. Data from in vitro, ex vivo, non-mammalian and mammalian animal models and epidemiological studies have been reviewed and discussed. RESULTS: MPs and NPs from non-biodegradable plastics affect organs, tissues and cells from sensitive systems such as the brain and reproductive organs. Both MPs and NPs induce oxidative stress, chronic inflammation, energy metabolism disorders, mitochondrial dysfunction and cytotoxicity, which in turn are responsible for neuroinflammation, dysregulation of synaptic functions, metabolic dysbiosis, poor gamete quality, and neuronal and reproductive toxicity. In spite of this mechanistic knowledge gained from studies of non-biodegradable plastics, relatively little is known about the adverse effects or molecular mechanisms of MPs and NPs from biodegradable plastics. CONCLUSION: The neurological and reproductive health risks of MPs/NPs exposure warrant serious consideration, and further studies on biodegradable plastics are recommended.

Stem Cells from Healthy and Tendinopathic Human Tendons: Morphology, Collagen and Cytokines Expression and Their Response to T3 Thyroid Hormone.

The aim of this study was to investigate the effect of triiodothyronine (T3) on tendon specific markers and cytokines expression of stem cells extracted from human tendons. Indeed, thyroid hormones have been reported to be protective factors, maintaining tendons' homeostasis, whereas tendinopathy is believed to be related to a failed healing response. Healthy and tendinopathic human tendons were harvested to isolate tendon stem/progenitor cells (TSPCs). TSPCs obtained from pathological samples showed gene expression and morphological modifications at baseline in comparison with cells harvested from healthy tissues. When cells were maintained in a medium supplemented with T3 (10-6 M), only pathological populations showed a significant upregulation of tenogenic markers (DCN, TNC, COL1A1, COL3A1). Immunostaining revealed that healthy cells constantly released type I collagen, typical of tendon matrix, whereas pathological ones overexpressed and secreted type III collagen, typical of scarred and impaired tissue. Pathological cells also overexpressed pro- and anti-inflammatory cytokines, suggesting an impaired balance in the presence of T3, without STAT3 activation. Moreover, DKK-1 was significantly high in the culture medium of pathological cell cultures and was reversed by T3. This study opens perspectives on the complex biochemical alteration of cells from pathological tendons, which may lead to the chronic disease context with an impaired extracellular matrix.

Tendon and Cytokine Marker Expression by Human Bone Marrow Mesenchymal Stem Cells in a Hyaluronate/Poly-Lactic-Co-Glycolic Acid (PLGA)/Fibrin Three-Dimensional (3D) Scaffold.

We developed a (three-dimensional) 3D scaffold, we named HY-FIB, incorporating a force-transmission band of braided hyaluronate embedded in a cell localizing fibrin hydrogel and poly-lactic-co-glycolic acid (PLGA) nanocarriers as transient components for growth factor controlled delivery. The tenogenic supporting capacity of HY-FIB on human-Bone Marrow Mesenchymal Stem Cells (hBM-MSCs) was explored under static conditions and under bioreactor-induced cyclic strain conditions. HY-FIB elasticity enabled to deliver a mean shear stress of 0.09 Pa for 4 h/day. Tendon and cytokine marker expression by hBM-MSCs were studied. Results: hBM-MSCs embedded in HY-FIB and subjected to mechanical stimulation, resulted in a typical tenogenic phenotype, as indicated by type 1 Collagen fiber immunofluorescence. RT-qPCR showed an increase of type 1 Collagen, scleraxis, and decorin gene expression (3-fold, 1600-fold, and 3-fold, respectively, at day 11) in dynamic conditions. Cells also showed pro-inflammatory (IL-6, TNF, IL-12A, IL-1ß) and anti-inflammatory (IL-10, TGF-ß1) cytokine gene expressions, with a significant increase of anti-inflammatory cytokines in dynamic conditions (IL-10 and TGF-ß1 300-fold and 4-fold, respectively, at day 11). Mechanical signaling, conveyed by HY-FIB to hBM-MSCs, promoted tenogenic gene markers expression and a pro-repair cytokine balance. The results provide strong evidence in support of the HY-FIB system and its interaction with cells and its potential for use as a predictive in vitro model.

Therapeutic potential of microRNA in tendon injuries.

INTRODUCTION: The regulatory role of microRNA (miRNA) in several conditions has been studied, but their function in tendon healing remains elusive. This review summarizes how miRNAs are related to the pathogenesis of tendon injuries and highlights their clinical potential, focusing on the issues related to their delivery for clinical purposes. SOURCES OF DATA: We searched multiple databases to perform a systematic review on miRNA in relation to tendon injuries. We included in the present work a total of 15 articles. AREAS OF AGREEMENT: The mechanism of repair of tendon injuries is probably mediated by resident tenocytes. These maintain a fine equilibrium between anabolic and catabolic events of the extracellular matrix. Specific miRNAs regulate cytokine expression and orchestrate proliferation and differentiation of stromal cell lines involved in the composition of the extracellular matrix. AREAS OF CONTROVERSY: The lack of effective delivery systems poses serious obstacles to the clinical translation of these basic science findings. GROWING POINT: In vivo studies should be planned to better explore the relationship between miRNA and tendon injuries and evaluate the most suitable delivery system for these molecules. AREAS TIMELY FOR DEVELOPING RESEARCH: Investigations ex vivo suggest therapeutic opportunities of miRNA for the management of tendon injuries. Given the poor pharmacokinetic properties of miRNAs, these must be delivered by an adequate adjuvant transport system.

Investigating the Mechanobiology of Cancer Cell-ECM Interaction Through Collagen-Based 3D Scaffolds.

Deregulated dynamics of the extracellular matrix (ECM) are one of the hallmarks of cancer. Studies on tumor mechanobiology are thus expected to provide an insight into the disease pathogenesis as well as potentially useful biomarkers. Type I collagen is among the major determinants of breast ECM structural and tensile properties, and collagen modifications during tumor evolution drive a number of disease-related processes favoring cancer progression and invasion. We investigated the use of 3D collagen-based scaffolds to identify the modifications induced by cancer cells on the mechanical and structural properties of the matrix, comparing cell lines from two breast tumor subtypes with different clinical aggressiveness. Orthotopic implantation was used to investigate the collagen content and architecture of in vivo breast tumors generated by the two cell lines. MDA-MB-231, which belongs to the aggressive basal-like subtype, increased scaffold stiffness and overexpressed the matrix-modifying enzyme, lysyl oxidase (LOX), whereas luminal A MCF-7 cells did not significantly alter the mechanical characteristics of extracellular collagen. This replicates the behavior of in vivo tumors generated by MDA-MB-231, characterized by a higher collagen content and higher LOX levels than MCF-7. When LOX activity was blocked, the ability of MDA-MB-231 to alter scaffold stiffness was impaired. Our model could constitute a relevant in vitro tool to reproduce and investigate the biomechanical interplay subsisting between cancer cells and the surrounding ECM and its impact on tumor phenotype and behavior.

Liposomes Size Engineering by Combination of Ethanol Injection and Supercritical Processing.

Supercritical fluid extraction using a high-pressure packed tower is proposed not only to remove the ethanol residue from liposome suspensions but also to affect their size and distribution leading the production of nanosomes. Different operating pressures, temperatures, and gas to liquid ratios were explored and ethanol was successfully extracted up to a value of 400 ppm; liposome size and distribution were also reduced by the supercritical processing preserving their integrity, as confirmed by Z-potential data and Trasmission Electron Microscopy observations. Operating at 120 bar and 38°C, nanosomes with a mean diameter of about 180 ± 40 nm and good storage stability were obtained. The supercritical processing did not interfere on drug encapsulation, and no loss of entrapped drug was observed when the water-soluble fluorescein was loaded as a model compound. Fluorescein encapsulation efficiency was 30% if pure water was used during the supercritical extraction as processing fluid; whereas an encapsulation efficiency of 90% was obtained if the liposome suspension was processed in water/fluorescein solution. The described technology is easy to scale up to an industrial production and merge in one step the solvent extraction, liposome size engineering, and an excellent drug encapsulation in a single operation unit.

Design of alginate-based aerogel for nonsteroidal anti-inflammatory drugs controlled delivery systems using prilling and supercritical-assisted drying.

In this study, a novel preparation method for alginate-based aerogels charged with nonsteroidal anti-inflammatory drugs (NSAIDs) was developed using prilling in combination with supercritical fluid technique. Nanoporous carriers were prepared by laminar jet breakup of drug/alginate solutions or suspensions followed by cross-linking in ethanol or aqueous CaCl(2) solutions, water replacement, and supercritical-CO(2) -assisted drying. A substantial drug loss was observed for highly soluble ketoprofen lysinate, whereas encapsulation efficiency was satisfying for slightly soluble ketoprofen. The tandem technique successfully produced almost spherical aerogels (sphericity coefficient 0.97-0.99) in narrow size distribution with reduced particle shrinkage and smooth surface (surface roughness 1.10-1.13); the internal porous texture of the parent hydrogels was preserved and appeared as a network of nanopores with diameters around 200 nm. Drug release profiles were monitored using a pH change method to evaluate the possible application of the aerogels as fast dissolving NSAIDs formulation. Aqueous cross-linking led to aerogels encapsulating ketoprofen in the amorphous form and with an enhanced burst effect in simulated gastric fluid (75% in 30 min), whereas ethanol cross-linking produced aerogels embedding drug in crystal clusters with slower dissolution rate. The system appears an interesting potential carrier for the fast delivery of slightly soluble drugs in the upper gastrointestinal tract.

PLGA microdevices for retinoids sustained release produced by supercritical emulsion extraction: continuous versus batch operation layouts.

Retinyl acetate (RA) was selected as a model compound to be entrapped in poly(lactic-co-glycolic)acid (PLGA) microspheres using supercritical emulsion extraction (SEE). Several oil-in-water emulsions prepared using acetone and aqueous glycerol (80% glycerol, 20% water) were processed using supercritical carbon dioxide (SC-CO2 ) to extract the oily phase and to induce microspheres formation. The characteristics of the microspheres obtained by conventional liquid emulsion extraction and SEE were also compared: SEE produced spherical and free flowing microspheres, whereas the conventional liquid-liquid extraction showed large intraparticles aggregation. Emulsion extraction by SC-CO2 technology was tested using two different operation layouts: batch (SEE-B) and continuous (SEE-C). SEE-C was performed using a packed tower to produce emulsion/SC-CO2 contact in countercurrent mode, allowing higher microsphere recovery and process efficiencies. Operating at 80 bar and 36°C, SEE-C produced PLGA/RA microspheres with mean sizes between 3.3 and 4.5 µm with an excellent encapsulation efficiency of 80%-90%. Almost all the drug was released in about 6 days when charged at 2.7% (w/w), whereas only 40% and 10% of RA were released in the same period of time when the charge was 5.2% and 8.8% (w/w), respectively. Release kinetics constants calculated from the experimental data, using a mathematical model, were also proposed and discussed.