A Finite Element Investigation into the Cohesive Properties of Glass-Fiber-Reinforced Polymers with Nanostructured Interphases.

Glass-fiber-reinforced polymer (GFRP) composites represent one of the most exploited composites due to their outstanding mechanical properties, light weight and ease of manufacture. However, one of the main limitations of GFRP composites is their weak inter-laminar properties. This leads to resin delamination and loss of mechanical properties.

Seeded-Growth Experiment Demonstrating Size- and Shape-Dependence on Gold Nanoparticle-Light Interactions.

Gold nanoparticles are exciting materials in nanotechnology and nanoscience research and are being applied across a wide range of fields including imaging, chemical sensing, energy storage, and cancer therapies. In this experiment, students will synthesize two sizes of gold nanospheres (~20 nm and ~100 nm) and will create gold nanostars utilizing a seed-mediated growth synthetic approach. Students will compare how each sample interacts differently with light (absorption and scattering) based on the nanoparticles' size and shape.

In vivo soft tissue reinforcement with bacterial nanocellulose.

The use of surgical meshes to reinforce damaged internal soft tissues has been instrumental for successful hernia surgery; a highly prevalent condition affecting yearly more than 20 million patients worldwide. Intraperitoneal adhesions between meshes and viscera are one of the most threatening complications, often implying reoperation or side effects such as chronic pain and bowel perforation. Despite recent advances in the optimization of mesh porous structure, incorporation of anti-adherent coatings or new approaches in the mesh fixation systems, clinicians and manufacturers are still pursuing an optimal material to improve the clinical outcomes at a cost-effective ratio.

Limbal Stem Cells on Bacterial Nanocellulose Carriers for Ocular Surface Regeneration.

Limbal stem cells (LSCs) are already used in cell-based treatments for ocular surface disorders. Clinical translation of LSCs-based therapies critically depends on the successful delivery, survival, and retention of these therapeutic cells to the desired region. Such a major bottleneck could be overcome by using an appropriate carrier to provide anchoring sites and structural support to LSC culture and transplantation.

Bacterial Nanocellulose and Titania Hybrids: Cytocompatible and Cryopreservable Cell Carriers.

Carrier-assisted cell transplantation offers new strategies to improve the clinical outcomes of cellular therapies. Bacterial nanocellulose (BC) is an emerging biopolymer that might be of great value in the development of animal-free, customizable, and temperature-stable novel cell carriers. Moreover, BC exhibits a myriad of modification possibilities to incorporate additional functionalities.

Reduction of the Lattice Thermal Conductivity of Polymer Semiconductors by Molecular Doping.

Here we show that molecular doping of polymer thermoelectrics increases the electrical conductivity while reducing the thermal conductivity. A high-throughput methodology based on annealing and doping gradients within individual films is employed to self-consistently analyze and correlate electrical and thermal characteristics for the equivalent of >100 samples. We focus on the benchmark material system poly(2,5-bis(3-alkylthiophen-2-yl)thieno[3,2-]thiophene) (PBTTT) doped with molecular acceptor 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ).

Multi-layered polydopamine coatings for the immobilization of growth factors onto highly-interconnected and bimodal PCL/HA-based scaffolds.

For bone tissue engineering applications, scaffolds that mimic the porous structure of the extracellular matrix are highly desirable. Herein, we employ a PCL/HA-based scaffold with a double-scaled architecture of small pores coupled to larger ones. To improve the osteoinductivity of the scaffold, we incorporate two different growth factors via polydopamine (PDA) coating.

Pristine and hydrated fluoroapatite (0001).

The surface structure of fluoroapatite (0001) (FAp) under quasi-dry and humid conditions has been probed with surface X-ray diffraction (SXRD). Lateral and perpendicular atomic relaxations corresponding to the FAp termination before and after HO exposure and the location of the adsorbed water molecules have been determined from experimental analysis of the crystal truncation rod (CTR) intensities. The surface under dry conditions exhibits a bulk termination with relaxations in the outermost atomic layers.

CCL21-loaded 3D hydrogels for T cell expansion and differentiation.

Recent achievements in the field of immunotherapy, such as the development of engineered T cells used in adoptive cell therapy, are introducing more efficient strategies to combat cancer. Nevertheless, there are still many limitations. For example, these T cells are challenging to manufacture, manipulate, and control.

Bacterial nanocellulose as a corneal bandage material: a comparison with amniotic membrane.

Corneal trauma and ulcerations are leading causes of corneal blindness around the world. These lesions require attentive medical monitoring since improper healing or infection has serious consequences in vision and quality of life. Amniotic membrane grafts represent the common solution to treat severe corneal wounds.

Bacterial nanocellulose from agro-industrial wastes: low-cost and enhanced production by Komagataeibacter saccharivorans MD1.

Bacterial nanocellulose (BNC) has been drawing enormous attention because of its versatile properties. Herein, we shed light on the BNC production by a novel bacterial isolate (MD1) utilizing various agro-industrial wastes. Using 16S rRNA nucleotide sequences, the isolate was identified as Komagataeibacter saccharivorans MD1.

Closing the Stability-Performance Gap in Organic Thermoelectrics by Adjusting the Partial to Integer Charge Transfer Ratio.

Two doping mechanisms are known for the well-studied materials poly(3-hexylthiophene) (P3HT) and poly(2,5-bis(3-alkylthiophen-2-yl)thieno[3,2-]thiophene) (PBTTT), namely, integer charge transfer (ICT) and charge transfer complex (CTC) formation. Yet, there is poor understanding of the effect of doping mechanism on thermal stability and the thermoelectric properties. In this work, we present a method to finely adjust the ICT to CTC ratio.

Mineralization-Inspired Synthesis of Magnetic Zeolitic Imidazole Framework Composites.

Metal-organic frameworks (MOFs) capable of mobility and manipulation are attractive materials for potential applications in targeted drug delivery, catalysis, and small-scale machines. One way of rendering MOFs navigable is incorporating magnetically responsive nanostructures, which usually involve at least two preparation steps: the growth of the magnetic nanomaterial and its incorporation during the synthesis of the MOF crystals. Now, by using optimal combinations of salts and ligands, zeolitic imidazolate framework composite structures with ferrimagnetic behavior can be readily obtained via a one-step synthetic procedure, that is, without the incorporation of extrinsic magnetic components.

Will organic thermoelectrics get hot?

The generally low energy density from most heat sources-the Sun, Earth as well as most human activities-implies that solid-state thermoelectric devices are the most versatile heat harvesters since, unlike steam engines, they can be used on a small scale and at small temperature differences. In this opinion piece, we first discuss the materials requirements for the widespread use of thermoelectrics. We argue that carbon-based materials, such as conducting polymers and carbon nanotubes, are particularly suited for large area and low-temperature operation applications, as they are abundant, low-toxicity and easy to process.

Functionalization of polyacrylamide for nanotrapping positively charged biomolecules.

Engineering new materials which are capable of trapping biomolecules in nanoscale quantities, is crucial in order to achieve earlier diagnostics in different diseases. This article demonstrates that using free radical copolymerization, polyacrylamide can be successfully functionalized with specific synthons for nanotrapping positively charged molecules, such as numerous proteins, through electrostatic interactions due to their negative charge. Specifically, two functional random copolymers, acrylamide/acrylic acid (1) and acrylamide/acrylic acid/-(pyridin-4-yl-methyl)acrylamide (2), whose negative net charges differ in their water solutions, were synthetized and their ability to trap positively charged proteins was studied using myoglobin as a proof-of-concept example.

Farming thermoelectric paper.

Waste heat to electricity conversion using thermoelectric generators is emerging as a key technology in the forthcoming energy scenario. Carbon-based composites could unleash the as yet untapped potential of thermoelectricity by combining the low cost, easy processability, and low thermal conductivity of biopolymers with the mechanical strength and good electrical properties of carbon nanotubes (CNTs). Here we use bacteria in environmentally friendly aqueous media to grow large area bacterial nanocellulose (BC) films with an embedded highly dispersed CNT network.

Opportunities of Bacterial Cellulose to Treat Epithelial Tissues.

In this mini-review, we highlight the potential of the biopolymer bacterial cellulose to treat damaged epithelial tissues. Epithelial tissues are cell sheets that delimitate both the external body surfaces and the internal cavities and organs. Epithelia serve as physical protection to underlying organs, regulate the diffusion of molecules and ions, secrete substances and filtrate body fluids, among other vital functions.

Impact of physicochemical properties of DNA/PEI complexes on transient transfection of mammalian cells.

Polyethyleneimine (PEI) has been used extensively for transient gene expression (TGE) in mammalian cell cultures. However, the relationship between DNA/PEI complex preparation and their biological activity has not been fully established. Here, a systematic study of DNA/PEI complexes, their physicochemical properties during formation and their transfection efficiency was performed on a virus-like particle (VLP) production platform.

Combining Adhesive Nanostructured Surfaces and Costimulatory Signals to Increase T Cell Activation.

Adoptive cell therapies are showing very promising results in the fight against cancer. However, these therapies are expensive and technically challenging in part due to the need of a large number of specific T cells, which must be activated and expanded in vitro. Here we describe a method to activate primary human T cells using a combination of nanostructured surfaces functionalized with the stimulating anti-CD3 antibody and the peptidic sequence arginine-glycine-aspartic acid, as well as costimulatory agents (anti-CD28 antibody and a cocktail of phorbol 12-myristate 13-acetate, ionomycin, and protein transport inhibitors).

Artificial 3D Culture Systems for T Cell Expansion.

Adoptive cell therapy, i.e., the extraction, manipulation, and administration of ex vivo generated autologous T cells to patients, is an emerging alternative to regular procedures in cancer treatment.

Stimuli-Responsive Functionalization Strategies to Spatially and Temporally Control Surface Properties: Michael vs Diels-Alder Type Additions.

Stimuli-responsive self-assembled monolayers (SAMs) are used to confer switchable physical, chemical, or biological properties to surfaces through the application of external stimuli. To obtain spatially and temporally tunable surfaces, we present microcontact printed SAMs of a hydroquinone molecule that are used as a dynamic interface to immobilize different functional molecules either via Diels-Alder or Michael thiol addition reactions upon the application of a low potential. In spite of the use of such reactions and the potential applicability of the resulting surfaces in different fields ranging from sensing to biomedicine through data storage or cleanup, a direct comparison of the two functionalization strategies on a surface has not yet been performed.

Integrin-Assisted T-Cell Activation on Nanostructured Hydrogels.

Adoptive cell therapy (ACT) has shown very promising results as treatment for cancer in a few clinical trials, such as the complete remissions of otherwise terminal leukemia patients. Nevertheless, the introduction of ACT into clinics requires overcoming not only medical but also technical challenges, such as the ex vivo expansion of large amounts of specific T-cells. Nanostructured surfaces represent a novel T-cell stimulation technique that enables us to fine-tune the density and orientation of activating molecules presented to the cells.

Bio-safe processing of polylactic-co-caprolactone and polylactic acid blends to fabricate fibrous porous scaffolds for in vitro mesenchymal stem cells adhesion and proliferation.

In this study, the design and fabrication of porous scaffolds, made of blends of polylactic-co-caprolactone (PLC) and polylactic acid (PLA) polymers, for tissue engineering applications is reported. The scaffolds are prepared by means of a bio-safe thermally induced phase separation (TIPS) approach with or without the addition of NaCl particles used as particulate porogen. The scaffolds are characterized to assess their crystalline structure, morphology and mechanical properties, and the texture of the pores and the pore size distribution.

Supercritical CO2 foamed polycaprolactone scaffolds for controlled delivery of 5-fluorouracil, nicotinamide and triflusal.

The manufacture of porous polycaprolactone (PCL) scaffolds containing three different drugs, namely 5-fluorouracil, nicotinamide and triflusal, was investigated in this work with the aim of obtaining bioactive systems with controlled drug delivery capabilities. The scaffolds were prepared by means of a supercritical CO2 (scCO2) foaming technique by optimizing the drug loading process. This was achieved by dissolving the drugs in organic solvents miscible with scCO2 and by mixing these drug/solvent solutions with PCL powder.