Physicochemical Characterization and In Vitro Activity of Poly(ε-Caprolactone)/Mycophenolic Acid Amorphous Solid Dispersions.

The obtention of amorphous solid dispersions (ASDs) of mycophenolic acid (MPA) in poly(ε-caprolactone) (PCL) is reported in this paper. An improvement in the bioavailability of the drug is possible thanks to the favorable specific interactions occurring in this system. Differential scanning calorimetry (DSC) was used to investigate the miscibility of PCL/MPA blends, measuring glass transition temperature (T) and analyzing melting point depression to obtain a negative interaction parameter, which indicates the development of favorable inter-association interactions.

Self-assembled three-dimensional hydrogels based on graphene derivatives and cerium oxide nanoparticles: scaffolds for co-culture of oligodendrocytes and neurons derived from neural stem cells.

Stem cell-based therapies have shown promising results for the regeneration of the nervous system. However, the survival and integration of the stem cells in the neural circuitry is suboptimal and might compromise the therapeutic outcomes of this approach. The development of functional scaffolds capable of actively interacting with stem cells may overcome the current limitations of stem cell-based therapies.

Lactide and Ethylene Brassylate-Based Thermoplastic Elastomers and Their Nanocomposites with Carbon Nanotubes: Synthesis, Mechanical Properties and Interaction with Astrocytes.

Polylactide (PLA) is among the most commonly used polymers for biomedical applications thanks to its biodegradability and cytocompatibility. However, its inherent stiffness and brittleness are clearly inappropriate for the regeneration of soft tissues (e.g.

In vitro preparation of human Dental Pulp Stem Cell grafts with biodegradable polymer scaffolds for nerve tissue engineering.

Human Dental Pulp Stem Cells (hDPSCs) are one of the most promising stem cell sources for tissue engineering and regeneration, due to their extraordinary multi-lineage differentiation ability, ease of extraction from biological waste in dental clinics, safe non-tumorigenic phenotype, immune-tolerance upon in vivo transplantation, and great possibilities of application in autologous tissue reconstruction. The in vitro manipulation of hDPSCs paves the way for drug screening and tailor-made regeneration of damaged tissues, in the context of personalized medicine. The neural crest phenotype of these stem cells gives them the capacity to differentiate to a large variety of cell types, including neural-lineage cells.

Lactide-Valerolactone Copolymers for Packaging Applications.

Lactide-valerolactone copolymers have potential application in the packaging sector. Different copolymers were synthesized, and the kinetics of the copolymerization reactions and the microstructure of the copolymers were analysed. Lactide showed higher reactivity than valerolactone which leads to composition drift through the reaction.

Amorphous solid dispersions in poly(ε-caprolactone)/xanthohumol bioactive blends: physicochemical and mechanical characterization.

This paper reports the obtention of amorphous solid dispersions (ASDs) of xanthohumol (XH) in PCL containing up to 50 wt% of the bioactive compound in the amorphous form thanks to the advantageous specific interactions established in this system. The miscibility of the PCL/XH blends was investigated using DSC. Melting point depression analysis yielded a negative interaction parameter indicating the occurrence of favorable inter-association interactions.

Smart Layer-by-Layer Polymeric Microreactors: pH-Triggered Drug Release and Attenuation of Cellular Oxidative Stress as Prospective Combination Therapy.

Polymer capsules fabricated the layer-by-layer (LbL) approach have emerged as promising biomedical systems for the release of a wide variety of therapeutic agents, owing to their tunable and controllable structure and the possibility to include several functionalities in the polymeric membrane during the fabrication process. However, the limitation of the capsules with a single functionality to overcome the challenges involved in the treatment of complex pathologies denotes the need to develop multifunctional capsules capable of targeting several mediators and/or mechanisms. Oxidative stress is caused by the accumulation of reactive oxygen species [, hydrogen peroxide (HO), hydroxyl radicals (OH), and superoxide anion radicals (O)] in the cellular microenvironment and is a key modulator in the pathology of a broad range of inflammatory diseases.

Advances and Perspectives in Dental Pulp Stem Cell Based Neuroregeneration Therapies.

Human dental pulp stem cells (hDPSCs) are some of the most promising stem cell types for regenerative therapies given their ability to grow in the absence of serum and their realistic possibility to be used in autologous grafts. In this review, we describe the particular advantages of hDPSCs for neuroregenerative cell therapies. We thoroughly discuss the knowledge about their embryonic origin and characteristics of their postnatal niche, as well as the current status of cell culture protocols to maximize their multilineage differentiation potential, highlighting some common issues when assessing neuronal differentiation fates of hDPSCs.

Novel Hydrogels of Chitosan and Poly(vinyl alcohol) Reinforced with Inorganic Particles of Bioactive Glass.

Chitosan (CS) and poly(vinyl alcohol) (PVA) hydrogels, a polymeric system that shows a broad potential in biomedical applications, were developed. Despite the advantages they present, their mechanical properties are insufficient to support the loads that appear on the body. Thus, it was proposed to reinforce these gels with inorganic glass particles (BG) in order to improve mechanical properties and bioactivity and to see how this reinforcement affects levofloxacin drug release kinetics.

Electrical percolation in extrinsically conducting, poly(ε-decalactone) composite neural interface materials.

By providing a bidirectional communication channel between neural tissues and a biomedical device, it is envisaged that neural interfaces will be fundamental in the future diagnosis and treatment of neurological disorders. Due to the mechanical mismatch between neural tissue and metallic neural electrodes, soft electrically conducting materials are of great benefit in promoting chronic device functionality. In this study, carbon nanotubes (CNT), silver nanowires (AgNW) and poly(hydroxymethyl 3,4-ethylenedioxythiophene) microspheres (MSP) were employed as conducting fillers within a poly(ε-decalactone) (EDL) matrix, to form a soft and electrically conducting composite.

Nanostructured scaffolds based on bioresorbable polymers and graphene oxide induce the aligned migration and accelerate the neuronal differentiation of neural stem cells.

Within the field of neural tissue engineering, there is a huge need for the development of materials that promote the adhesion, aligned migration and differentiation of stem cells into neuronal and supportive glial cells. In this study, we have fabricated bioresorbable elastomeric scaffolds combining an ordered nanopatterned topography together with a surface functionalization with graphene oxide (GO) in mild conditions. These scaffolds allowed the attachment of murine neural stem cells (NSCs) without the need of any further coating of its surface with extracellular matrix adhesion proteins.

Benefits of Polydopamine as Particle/Matrix Interface in Polylactide/PD-BaSO Scaffolds.

This work reports the versatility of polydopamine (PD) when applied as a particle coating in a composite of polylactide (PLA). Polydopamine was observed to increase the particle-matrix interface strength and facilitate the adsorption of drugs to the material surface. Here, barium sulfate radiopaque particles were functionalized with polydopamine and integrated into a polylactide matrix, leading to the formulation of a biodegradable and X-ray opaque material with enhanced mechanical properties.

High Throughput Manufacturing of Bio-Resorbable Micro-Porous Scaffolds Made of Poly(L-lactide-co-ε-caprolactone) by Micro-Extrusion for Soft Tissue Engineering Applications.

Porous scaffolds made of elastomeric materials are of great interest for soft tissue engineering. Poly(L-lactide-co--caprolactone) (PLCL) is a bio-resorbable elastomeric copolymer with tailorable properties, which make this material an appropriate candidate to be used as scaffold for vascular, tendon, and nerve healing applications. Here, extrusion was applied to produce porous scaffolds of PLCL, using NaCl particles as a leachable agent.

Correction: Novel biodegradable and non-fouling systems for controlled-release based on poly(ε-caprolactone)/Quercetin blends and biomimetic bacterial S-layer coatings.

[This corrects the article DOI: 10.1039/C9RA04398E.].

Novel biodegradable and non-fouling systems for controlled-release based on poly(ε-caprolactone)/Quercetin blends and biomimetic bacterial S-layer coatings.

Quercetin is a strong antioxidant with low bioavailability due to its high crystallinity. A further drawback is that Quercetin has potentially toxic effects at high concentrations. To improve this low water solubility, as well as control the concentration of the flavonoid in the body, Quercetin is incorporated into a polymeric matrix to form an amorphous solid dispersion (ASD) stable enough to resist the recrystallization of the drug.

Morphology and mechanical properties of poly(ethylene brassylate)/cellulose nanocrystal composites.

Poly(ethylene brassylate), a novel inexpensive biodegradable polyester, has been reinforced with cellulose nanocrystals (CNCs) with the aim of improving its thermal stability and mechanical properties. The composites have been characterized through calorimetry, tensile tests, thermogravimetry and electron microscopy. The addition of small amounts of CNCs improves both the stiffness and the ductility of the composites, suggesting the existence of some compatibilizing effect.

Analysis of a poly(ε-decalactone)/silver nanowire composite as an electrically conducting neural interface biomaterial.

Background: Advancement in polymer technologies, facilitated predominantly through chemical engineering approaches or through the identification and utilization of novel renewable resources, has been a steady focus of biomaterials research for the past 50 years. Aliphatic polyesters have been exploited in numerous biomedical applications including the formulation of soft-tissue sutures, bone fixation devices, cardiovascular stents etc. Biomimetic 'soft' polymer formulations are of interest in the design of biological interfaces and specifically, in the development of implantable neuroelectrode systems intended to interface with neural tissues.

Release mechanisms of urinary tract antibiotics when mixed with bioabsorbable polyesters.

In depth knowledge of the thermal properties of drugs is particularly important when they are designed for incorporation into a thermoplastic polymer matrix. In this paper a representative set of Urinary Tract Infection (UTI) antibiotics were studied using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), and then blended via solvent-casting method with poly(D,L-lactide-co-ε-caprolactone). Of these, amoxicillin, cefdinir, levofloxacin and norfloxacin showed a co-continuous morphology with the polyester, whereas blends with ciprofloxacin, nitrofurantoin and tobramycin resulted in two immiscible phases.

Catechol End-Functionalized Polylactide by Organocatalyzed Ring-Opening Polymerization.

There is a great interest in incorporating catechol moieties into polymers in a controlled manner due to their interesting properties, such as the promotion of adhesion, redox activity or bioactivity. One possibility is to incorporate the catechol as end-group in a polymer chain using a functional initiator by means of controlled polymerization strategies. Nevertheless, the instability of catechol moieties under oxygen and basic pH requires tedious protection and deprotection steps to perform the polymerization in a controlled fashion.

Antioxidant functionalized polymer capsules to prevent oxidative stress.

Unlabelled: Polymeric capsules exhibit significant potential for therapeutic applications as microreactors, where the bio-chemical reactions of interest are efficiently performed in a spatial and time defined manner due to the encapsulation of an active biomolecule (e.g., enzyme) and control over the transfer of reagents and products through the capsular membrane.

Preparation of Nanocomposites of Poly(ε-caprolactone) and Multi-Walled Carbon Nanotubes by Ultrasound Micro-Molding. Influence of Nanotubes on Melting and Crystallization.

Ultrasound micro-molding technology was successfully applied to prepare nanocomposites based on a poly(ε-caprolactone) (PCL) matrix and multi-walled carbon nanotubes (MWCNTs). Optimization of processing parameters (i.e.

Functionalised collagen spheres reduce HO mediated apoptosis by scavenging overexpressed ROS.

Excess reactive oxygen species (ROS) has been implicated in numerous diseases including cancer, cardiovascular and neurodegenerative diseases. Overexpression of ROS can lead to oxidative stress and subsequently to HO-mediated cell apoptosis. In this study, it was demonstrated that biodegradable PLGA microspheres coated with collagen type I and decorated with MnO nanoparticles acted as ROS scavengers controlling the HO-mediated apoptosis of cells undergoing oxidative stress.

Recent developments in drug eluting devices with tailored interfacial properties.

Drug eluting devices have greatly evolved during past years to become fundamental products of great marketing importance in the biomedical field. There is currently a large diversity of highly specialized devices for specific applications, making the development of these devices an exciting field of research. The replacement of the former bare metal devices by devices loaded with drugs allowed the sustained and controlled release of drugs, to achieve the desired local therapeutic concentration of drug.