Antimicrobial Activity of Copolymer Structures from Bio-Based Monomers.

The urgent need for new antimicrobial compounds has led scientists to explore antimicrobial peptides (AMPs) and antimicrobial polymers as solutions for multidrug resistance. In this study, we synthesized copolymers with cationic and hydrophobic moieties by free-radical polymerization (FRP) using a chain transfer agent to control molecular weights. The potential of natural products as part of the hydrophobic moiety was evaluated, along with variations in their monomer content (13-25%) and the molecular weight (MW) of the copolymer (5000-20,000 g·mol).

Improved Interfacial Electron Dynamics with Block Poly(4-vinylpyridine)-Poly(styrene) Polymers for Efficient and Long-Lasting Dye-Sensitized Solar Cells.

Dye-sensitized solar cells (DSSCs) have recently entered the market for indoor photovoltaics. Fast electron injection from dye to titania, the lifetime of the excited dye, and the suppression of back electron recombination at the photoanode/electrolyte interface are crucial for a high photocurrent conversion efficiency (PCE). This study presents block copolymers of poly(4-vinylpyridine) and poly(styrene)-P4VP--PSt as efficient accelerators of electron injection from dye to titania with extended lifetime excited states and long-lasting back electron recombination suppression.

Recycling Polyethylene/Polyamide Multilayer Films with Poly(isoprene--Maleic Anhydride) Compatibilizer.

Polymers generally form incompatible mixtures that make the process of recycling difficult, especially the mechanical recycling of mixed plastic waste. One of the most commonly used films in the packaging industry is multilayer films, mainly composed of polyethylene (PE) and polyamide (PA). Recycling these materials with such different molecular structures requires the use of compatibilizers to minimize phase separation and obtain more useful recycled materials.

Electrochemically Mediated Atom Transfer Radical Polymerization Driven by Alternating Current.

Alternating current (AC) and pulsed electrolysis are gaining traction in electro(organic) synthesis due to their advantageous characteristics. We employed AC electrolysis in electrochemically mediated Atom Transfer Radical Polymerization (eATRP) to facilitate the regeneration of the activator Cu complex on Cu electrodes. Additionally, Cu served as a slow supplemental activator and reducing agent (SARA ATRP), enabling the activation of alkyl halides and the regeneration of the Cu activator through a comproportionation reaction.

Replacing Harmful Flame Retardants with Biodegradable Starch-Based Materials in Polyethylene Formulations.

The addition of toxic flame retardants to commercially available polymers is often required for safety reasons due to the high flammability of these materials. In this work, the preparation and incorporation of efficient biodegradable starch-based flame retardants into a low-density polyethylene (LDPE) matrix was investigated. Thermoplastic starch was first obtained by plasticizing starch with glycerol/water or glycerol/water/choline phytate to obtain TPS-G and TPS-G-CPA, respectively.

Fast-Gelling Polyethylene Glycol/Polyethyleneimine Hydrogels Degradable by Visible-Light.

The treatment of burn wounds remains a clinical challenge due to the need for repeated dressings changes. Therefore, the development of a dressing system that can be atraumatically removed from the wound bed can be considered a breakthrough and improve treatment times. In this work, the development of an injectable, fast-gelling hydrogel is proposed that can change its mechanical properties when exposed to visible light.

Facile Synthesis of Highly Stretchable, Tough, and Photodegradable Hydrogels.

Recently, highly stretchable and tough hydrogels that are photodegradable on-demand have been reported. Unfortunately, the preparation procedure is complex due to the hydrophobic nature of the photocrosslinkers. Herein, a simple method is reported to prepare photodegradable double-network (DN) hydrogels that exhibit high stretchability, toughness, and biocompatibility.

Targeted downregulation of MYC mediated by a highly efficient lactobionic acid-based glycoplex to enhance chemosensitivity in human hepatocellular carcinoma cells.

The chemosensitization of tumor cells by gene therapy represents a promising strategy for hepatocellular carcinoma (HCC) treatment. In this regard, HCC-specific and highly efficient gene delivery nanocarriers are urgently needed. For this purpose, novel lactobionic acid-based gene delivery nanosystems were developed to downregulate c-MYC expression and sensitize tumor cells to low concentration of sorafenib (SF).

pH-responsive nanoparticles based on POEOMA-b-PDPA block copolymers for RNA encapsulation, protection and cell delivery.

The use of gene-based products, such as DNA or RNA, is increasingly being explored for various innovative therapies. However, the success of these strategies is highly dependent on the effective delivery of these biomolecules to target cells. Therefore, the development of pH-responsive nanoparticles comprises the creation of intelligent delivery systems with high therapeutic efficiency.

Scaling-Up an Aqueous Self-Degassing Electrochemically Mediated ATRP in Dispersion for the Preparation of Cellulose-Polymer Composites and Films.

Electrochemically mediated atom transfer radical polymerization (ATRP) is developed in dispersion conditions to assist the preparation of cellulose-based films. Self-degassing conditions are achieved by the addition of sodium pyruvate (SP) as a ROS scavenger, while an aluminum counter electrode provides a simplified and more cost-effective electrochemical setup. Different polyacrylamides were grown on a model cellulose substrate which was previously esterified with 2-bromoisobutyrate (-BriB), serving as initiator groups.

Photo-degradable, tough and highly stretchable hydrogels.

We present for the first time highly stretchable and tough hydrogels with controlled light-triggered photodegradation. A double-network of alginate/polyacrylamide (PAAm) is formed by using covalently and ionically crosslinked subnetworks. The ionic Ca alginate interpenetrates a PAAm network covalently crosslinked by a bifunctional acrylic crosslinker containing the photodegradable -nitrobenzyl (ONB) core instead of the commonly used methylene bisacrylamide (MBAA).

Dual electrochemical and chemical control in atom transfer radical polymerization with copper electrodes.

In Atom Transfer Radical Polymerization (ATRP), Cu acts as a supplemental activator and reducing agent (SARA ATRP) by activating alkyl halides and (re)generating the Cu activator through a comproportionation reaction, respectively. Cu is also an unexplored, exciting metal that can act as a cathode in electrochemically mediated ATRP (ATRP). Contrary to conventional inert electrodes, a Cu cathode can trigger a dual catalyst regeneration, simultaneously driven by electrochemistry and comproportionation, if a free ligand is present in solution.

Application of vinyl polymer-based materials as nucleic acids carriers in cancer therapy.

Nucleic acid-based therapies have changed the paradigm of cancer treatment, where conventional treatment modalities still have several limitations in terms of efficacy and severe side effects. However, these biomolecules have a short half-life in vivo, requiring multiple administrations, resulting in severe suffering, discomfort, and poor patient compliance. In the early days of (nano)biotechnology, these problems caused concern in the medical community, but recently it has been recognized that these challenges can be overcome by developing innovative formulations.

Fabrication of 3D scaffolds based on fully biobased unsaturated polyester resins by microstereo-lithography.

Additive Manufacturing (AM) technologies are an effective route to fabricate tailor made scaffolds for tissue engineering (TE) and regenerative medicine, with microstereo-lithography (µSLA) being one of the most promising techniques to produce high quality 3D structures. Here, we report the crosslinking studies of fully biobased unsaturated polyesters (UPs) with 2-hydroxyethyl methacrylate (HEMA) as the unsaturated monomer (UM), using thermal and µSLA crosslinking processes. The resulting resins were fully characterized in terms of their thermal and mechanical properties.

Development of light-degradable poly(urethane-urea) hydrogel films.

Biocompatible hydrogels are exciting platforms that have stood out in recent years for their outstanding potential for biomedical applications. For these applications, the ability of the material to respond to an external stimulus can be a relevant addition. This responsiveness allows the material to modify its physical properties in such a way that it can deliver molecules that support the healing process or allow easy removal of the films from the tissue.

Development of electrospun mats based on hydrophobic hydroxypropyl cellulose derivatives.

In this work, hydroxypropyl cellulose esters (HPCE) with long aliphatic chains were prepared and innovatively used in electrospinning to obtain hydroxypropyl cellulose (HPC)-based mats with enhanced resistance to moist environments. The described approach is very simple and does not require any post-treatment (e.g.

Process Development for Flexible Films of Industrial Cellulose Pulp Using Superbase Ionic Liquids.

Due to environmental concerns, more attention has been given to the development of bio-based materials for substitution of fossil-based ones. Moreover, paper use is essential in daily routine and several applications of industrial pulp can be developed. In this study, transparent films were produced by industrial cellulose pulp solubilization in tetramethylguanidine based ionic liquids followed by its regeneration.

Light-Activated Antimicrobial Surfaces Using Industrial Varnish Formulations to Mitigate the Incidence of Nosocomial Infections.

Evidence has shown that hospital surfaces are one of the major vehicles of nosocomial infections caused by drug-resistant pathogens. Smart surface coatings presenting multiple antimicrobial activity mechanisms have emerged as an advanced approach to safely prevent this type of infection. In this work, industrial waterborne polyurethane varnish formulations containing for the first time cationic polymeric biocides (SPBs) combined with photosensitizer curcumin were developed to afford contact-active and light-responsive antimicrobial surfaces.

Catalytic Halogen Exchange in Supplementary Activator and Reducing Agent Atom Transfer Radical Polymerization for the Synthesis of Block Copolymers.

Synthesis of block copolymers (BCPs) by catalytic halogen exchange (cHE) is reported, using supplemental activator and reducing agent Atom Transfer Radical Polymerization (SARA ATRP). The cHE mechanism is based on the use of a small amount of a copper catalyst in the presence of a suitable excess of halide ions, for the synthesis of block copolymers from macroinitiators with monomers of mismatching reactivity. cHE overcomes the problem of inefficient initiation in block copolymerizations in which the second monomer provides dormant species that are more reactive than the initiator.

The Impact of the Addition of Compatibilizers on Poly (lactic acid) (PLA) Properties after Extrusion Process.

Poly (lactic acid) (PLA), due to its biodegradability, biocompatibility, and renewability, is one of the most promising biobased polymers for replacing some of the petrol-based materials. Low flexibility of PLA is overcome, by blending it with olefin-based polymers, such as polypropylene (PP). However, the use of compatibilizing agents is required to attain final materials with suitable mechanical properties.

Development of red-light cleavable PEG-PLA nanoparticles as delivery systems for cancer therapy.

The development of targeted delivery systems can improve the selectivity of cancer drugs. Additionally, a system that promotes the controlled delivery of the drug triggered by an external stimulus in the exact target tissue is highly desirable. Regarding the light stimulus, the NIR window (650-950 nm) is the most suitable due to its higher capacity of penetration in human tissues and less harmful effects on normal cells.

A Preliminary Evaluation of the Pro-Chondrogenic Potential of 3D-Bioprinted Poly(ester Urea) Scaffolds.

Degeneration of articular cartilage (AC) is a common healthcare issue that can result in significantly impaired function and mobility for affected patients. The avascular nature of the tissue strongly burdens its regenerative capacity contributing to the development of more serious conditions such as osteoarthritis. Recent advances in bioprinting have prompted the development of alternative tissue engineering therapies for the generation of AC.

Calcium Phosphate Ceramics Can Prevent Bisphosphonate-Related Osteonecrosis of the Jaw.

Bisphosphonate-associated osteonecrosis of the jaw (BRONJ), a post-surgical non-healing wound condition, is one of the most common side effects in patients treated with nitrogen-containing bisphosphonates. Its physiopathology has been related with suppression of bone turnover, of soft tissue healing and infection. Biphasic calcium phosphates (BCP) are used as a drug delivery vehicle and as a bone substitute in surgical wounds.