A mechanochemical approach was utilized for the synthesis of naloxone covalently linked poly(lactic acid) and nanoparticles. This preparation was achieved using lactide as a monomer in anionic ring opening polymerization, naloxone as a drug initiator, and CHCl3 to perform liquid-assisted grinding. This process resulted in the direct preparation of a naloxone nanoparticle with a drug loading of similar to 8.3% w/w and nanoparticles around 600 nm. These findings underscore the promise of mechanochemistry in developing drug delivery systems.

Polysaccharides, including chitin, are one of the most abundant biopolymers in nature and are increasingly recognized as a sustainable alternative to petroleum-derived plastics and synthetic fillers in polymer composites. Traditionally sourced from crustacean shells, chitin offers mechanical strength and biocompatibility with limitations also in processability and functionality. Fungal-derived chitin material represents a promising alternative, with advantages including scalable fermentation on low-cost substrates, absence of shellfish allergens, and tunable molecular architectures that vary by species, developmental stage, and growth environment. In this study, we systematically examined chitinous materials obtained from taxonomically and functionally distinct fungi, Laccaria bicolor, Trichoderma reesei and Rhizopus oryzae, to assess their structural, chemical, and morphological properties as reinforcement agents in polymer composites. Mild alkaline pretreatment was employed to obtain mycelium chitin particles, thereby improving accessibility to chitin and co-occurring β-D-glucans while maintaining microparticle integrity. Comprehensive FTIR and solid-state NMR analyses revealed species-specific differences in chemical composition and microstructure, with R. oryzae exhibiting a unique spectral signature. These fungal-derived chitin were then incorporated into poly(vinyl alcohol) (PVA) hydrogels, where they acted as reinforcing fillers without the need for additional chemical crosslinkers. Comparative evaluation of hydrogel properties demonstrated that fungal chitin significantly enhanced mechanical performance, with all mycelium fillers mitigating the water weakening in PVA hydrogels. R. oryzae-derived composites tripled the hydrogel tensile strength while the submicron fibrous morphology in L. bicolor contributes to over 45 % tensile improvement in dry PVA composites. Our findings highlight the potential of fungal biomass as a tunable, sustainable platform for producing chitin-based reinforcing agents.

Cryptococcus neoformans is an opportunistic fungal pathogen that causes meningitis in >152,000 immunocompromised individuals annually, leading to 112,000 yearly deaths. The four classes of existing antifungal agents target plasma membrane sterols (ergosterol), nucleic acid synthesis, and cell wall synthesis. Existing drugs are not highly effective against Cryptococcus, and antifungal drug resistance is an increasing problem. A novel antimicrobial compound, a eumelanin-inspired indoylenepheyleneethynylene, EIPE-1, was synthesized and has antimicrobial activity against Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MSRA), but not towards Gram-negative organisms. Based on EIPE-1’s antibacterial activity, we hypothesized that EIPE-1 could have antifungal activity. For these studies, we tested EIPE-1 against C. neoformans strain H99 and 6 additional cryptococcal clinical isolates. We examined antifungal activity, cytotoxicity, effects on fungal gene expression, and mechanism of action of EIPE-1. Results showed that EIPE-1 has fungicidal effects on seven cryptococcal strains with MICs ranging from 1.56 to 3.125 μg/mL depending on the strain, and it is non-toxic to mammalian cells. We conducted scanning and transmission electron microscopy on the exposed cells to examine structural changes to the organism following EIPE-1 treatment. Cells exposed displayed structural changes to their cell wall and membranes, with internal contents leaking out of the cells. To understand the effect of EIPE-1 on fungal gene expression, RNA sequencing was conducted. Results showed that EIPE-1 affects several processes involved stress response, ergosterol biosynthesis, capsule biosynthesis, and cell wall attachment and remodeling. Therefore, our studies demonstrate that EIPE-1 has antifungal activity against C. neoformans, which affects both cellular structure and gene expression of multiple fungal pathways involved in cell membrane stability and viability.

Due to their notable antimicrobial activity and optical properties, Schiff base ligands, along with their lanthanide and transition metal complexes, have seen extensive use in various applications. However, despite their potential, a comprehensive investigation into lanthanide and transition metal complexes using the same Schiff base ligand has not been reported to date. In this study, coordination compounds of lanthanide and transition metal ions were synthesized from the Schiff base ligand salicylaldehyde‐dipropylenetriamine. These complexes were characterized by elemental analysis, 1H and 13C NMR, mass spectroscopy, Fourier‐transform infrared spectroscopy ultraviolet–visible spectroscopy (UV–Vis), fluorescence spectroscopy, molar conductivity measurements, and thermogravimetric studies. Furthermore, the molecular structure of the Co (II) complex was determined by means of X‐ray crystallography. Thermogravimetric studies illustrated endothermic and non‐spontaneous degradation pathways of the complexes. UV–Vis spectra showed a new absorption band attributed to the ligand‐to‐metal charge transfer peak supporting the complexation between the ligand and metals. The lanthanide complexes exhibited distinctive luminescence emissions in the Sm (III), Tb (III), and Eu (III) complexes. This observation suggests that the ligand possesses the capability to absorb and efficiently transfer energy to the metal center of these lanthanide ions, thereby resulting in their characteristic luminescent properties. Additionally, antimicrobial investigations revealed that transition metal complexes generally exhibited antimicrobial activity against both gram‐positive and gram‐negative bacterial strains compared to lanthanide metal complexes, in most cases. However, it is noteworthy that the Dy (III) complex displayed the lowest minimum inhibitory concentration and minimum biocidal concentration values of 16 μg/ml against Staphylococcus epidermidis, indicating its potential as a candidate for the treatment of this pathogenic bacterium. The main purpose of this article is to investigate the variations in the synthesis and characterization of lanthanide and transition metal complexes utilizing the same Schiff base ligand suitable for applications in the pharmaceutical industry and optical material sciences.

Introduction Unique impermeability properties of the gram-negative outer cell envelope typically render these organisms intrinsically resistant to hydrophobic antibacterial compounds. Eumelanin-inspired indoylenephenyleneethynylene (EIPE) compounds possess scaffolding to which functional groups were attached to potentially provide antibacterial properties in the forms of hydrophilic (EIPE-HCl) and hydrophobic (EIPE-1) derivatives. Methods Standardized disk agar diffusion and microbroth dilution bioassays were employed to assess the susceptibility of disparate gram-negative and gram-positive bacterial pathogens to the two compounds. EIPE-1 mechanisms of action and intrinsic resistance were further investigated turbidimetrically in batch cultures with the aid of the gram-negative outer membrane permeabilizer compound 48/80. Results Hydrophobic derivative EIPE-1 exhibited a gram-positive antibacterial spectrum, while hydrophilic derivative EIPE-HCl possessed no antibacterial properties. EIPE-1 exhibited minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values below 2.0 µg/mL against all gram-positive bacteria, including two methicillin-resistant strains. In contrast, MIC/MBC values greater than 128 µg/mL were obtained for all gram-negative bacteria examined. Susceptibility of two strains of the strict anaerobe Clostridioides difficile indicated the EIPE-1 mechanism of action does not require molecular oxygen. Turbidimetric growth curves revealed EIPE-1 induced rapid bacteriolysis of Bacillus subtilis ATCC 6633, thereby suggesting a membrane-directed modality. Lastly, the outer membrane permeabilizer compound 48/80 failed to markedly sensitize any of three phylogenetically disparate gram-negative organisms to EIPE-1. Conclusion These data suggest that the hydrophobic melanin-inspired derivative EIPE-1 inhibits gram-positive bacteria in a cytoplasmic membrane-directed manner independent of oxygen. Moreover, a secondary mechanism may function concomitantly with outer membrane exclusionary properties to underly the intrinsic resistance of gram-negative pathogens.

Due to its biodegradable and biocompatible nature, poly(lactic acid) (PLA) has found widespread use in biomedical applications. Controlled drug delivery using PLA-based nanoparticles (PLA-NPs) is an important tool for tuning the bioavailability of therapeutics. Traditional methods to prepare PLA-NPs require a multistep process that is time-consuming and produces significant aqueous and organic waste streams. This work reports a one-pot mechanochemical synthesis of lactide to PLA-NPs. In this report, we developed and trained an artificial neural network algorithm to optimize PLA and PLA-NP preparation. Our results demonstrate a robust and optimized one-pot method for preparing precisely defined nanoparticles that generates minimal waste.

Organic semiconductors (OSCs) are promising advanced materials, due to various advantages including their lightweight, flexibility and processability. As a result, applications for their use in organic photovoltaics, organic light-emitting diodes, and organic field-effect transistors have been identified. However, up to this point, most of the feedstock from which OSCs are synthesized comes from nonrenewable resources, such as petroleum and coal. It is imperative to switch to renewable feedstocks to ensure a sustainable future; therefore there has been considerable effort to synthesize OSCs from sustainable feedstocks. There are many compounds present in nature, which could be used as OSCs as found in their natural forms. Similarly, there are also many natural moieties that could be modified, oligomerized, or polymerized to synthesize OSCs. In this chapter, we cover a wide range of examples of such research occurring in the last few decades.

Herein are reported the syntheses of poly(9,9-di-n-octylfluorenyl-2,7-diyl) (PF), poly(9,9-dioctylfluorene-alt-benzothiadiazole) (PFBT), and poly[(9,9-bis(3′-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN) by employing catalytic mechanochemical Suzuki polymerization in a ball mill. This mechanochemical synthesis technique can yield soluble functionalized polyfluorenes and its derivatives in 30 min or less. Furthermore, the polymer light emitting diode and photovoltaic interfacial electrolyte, poly(9,9-bis(3′-(N,N-dimethyl)-N-ethylammoinium-propyl-2,7-fluorene)-alt-2,7-(9,9-dioctylfluprene))dibromide (PFN-Br), was obtained via a facile mechanochemical quaternization reaction at the terminal amino groups of PFN.

The reliance on antibiotics and antimicrobials to treat bacterial infectious diseases is threatened by the emergence of antibiotic resistance and multi-drug-resistant organisms, thus having the potential to greatly impact human health. Thus, the discovery and development of antimicrobials capable of acting on antibiotic-resistant bacteria is a major area of significance in scientific research. Herein, we present the development of a eumelanin-inspired antimicrobial capable of killing methicillin-resistant Staphylococcus aureus (MRSA). By ligating quaternary ammonium-functionalized "arms" to a eumelanin-inspired indole with intrinsic antimicrobial activity, an antimicrobial agent with enhanced activity was prepared. This resulting antimicrobial, EIPE-1, had a minimum inhibitory concentration of 16 μg/mL (17.1 μM) against a clinical isolate of MRSA obtained from an adult cystic fibrosis patient. The biocidal activity occurred within 30 min of exposure and resulted in changes to the bacterial cell surface as visualized with a scanning electron microscope. Taken together, these studies demonstrate that EIPE-1 is effective at killing MRSA.

Typically, Suzuki couplings used in polymerizations are performed at raised temperatures in inert atmospheres. As a result, the synthesis of aromatic materials that utilize this chemistry often demands expensive and specialized equipment on an industrial scale. Herein, we describe a bimetallic methodology that exploits the distinct reactivities of palladium and copper to perform high yielding aryl-aryl dimerizations and polymerizations that can be performed on a benchtop under ambient conditions. These couplings are facile and can be performed by simple mixing in the open vessel. To demonstrate the utility of this method in the context of polymer synthesis: polyfluorene, polycarbazole, polysilafluorene, and poly(6,12-dihydro-dithienoindacenodithiophene) were created at ambient temperature and open to air.

The mu opioid receptor antagonist naloxone has been a vital, long-standing countermeasure in the ongoing battle against opioid use disorders (OUD) and toxicity. However, due to its distinctive short elimination half-life, naloxone has shown diminished efficacy in cases of synthetic opioid poisoning as larger or repeated doses of the antidote have been required to achieve adequate reversal of severe respiratory depression and prevent episodes of renarcotization. This report describes the synthesis, characterization, and in vivo evaluation of a novel, nanoparticle-based naloxone formulation that provides extended protection against the toxic effects of the powerful synthetic opioid fentanyl. The strategy was predicated on a modified two-step protocol involving the synthesis and subsequent nanoprecipitation of a poly(lactic-co-glycolic acid) polymer scaffold bearing a covalently linked naloxone chain end (drug loading ∼7% w/w). Pharmacokinetic evaluation of the resulting covalently loaded naloxone nanoparticles (cNLX-NP) revealed an elimination half-life that was 34 times longer than high dose free naloxone (10 mg/kg) in male Sprague-Dawley rats. This enhancement was further demonstrated by cNLX-NP in subsequent in vivo studies affording protection against fentanyl-induced respiratory depression and antinociception for up to 48 h following a single intramuscular injection. These discoveries support further investigation of cNLX-NP as a potential therapeutic to reverse overdose and prevent renarcotization from fentanyl and its potent analogs.

Multifunctional carbon fiber-reinforced polymer (CFRP) composites are promising structural materials for lightweight applications. However, the low conductivity in the through-thickness direction of the composites limits its applications in the fields that require the high stability of composite against lightning strikes. This work presents the study on the synergetic effect of conducting polymer, polyaniline (PANI), and graphene nanoplatelets (GNP) for increasing the electrical conductivity of CFRP composites. PANI doped GNP flexible film is fabricated with the aid of compatible polymer polyvinylpyrrolidone (PVP), and its effect on the electrical conductivity of CFRP composites has been studied. About 250% in through-thickness conductivity has improved with 11 wt% GNP as a function of the composite. The incorporation of conductive film not only increases the conductivity of the CFRP laminates but also enhances the resistance against lightning strikes. Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), three-point bending tests were used to analyze the morphology, thermal stability, and mechanical strengths of the composites. Finally, the observation of post-strike damage confirms the importance of through-thickness conductivity for mitigating the lightning strike damage.

This study introduces a benzodithiophene-S,S-tetraoxide (BDTT) monomer as an acceptor and 3,4-ethylenedioxythiophene flanked thiophene (TEDOT2) and terthiophene (T-3) as donor molecules for polymer formation. The synthesis of the poly(TEDOT2-BDTT) and poly(T-3-BDTT) copolymers was performed via a single-step monomer radical formation that is typically associated with electropolymerization methods. The electropolymerization is controlled by using a suitable monomer stoichiometric ratio that enables the deposition of copolymer thin films on the working electrode. Resultant copolymers were investigated by electrochemical analysis and their electronic properties are discussed in detail. A low average electron transport resistance of 16.5 omega was found for poly(TEDOT2-BDTT), indicating excellent conductive behavior. Solid-state absorbance and emission studies of the copolymers show visible to near-infrared spectral activity. Results support an effective strategy towards highly efficient electronically conducting polymers (ECPs) based on a unique BDTT monomer.

Advancements in electrode technologies to both stimulate and record the central nervous system’s electrical activities are enabling significant improvements in both the understanding and treatment of different neurological diseases. However, the current neural recording and stimulating electrodes are metallic, requiring invasive and damaging methods to interface with neural tissue. These electrodes may also degrade, resulting in additional invasive procedures. Furthermore, metal electrodes may cause nerve damage due to their inherent rigidity. This paper demonstrates that novel electrically conductive organic fibers (ECFs) can be used for direct nerve stimulation. The ECFs were prepared using a standard polyester material as the structural base, with a carbon nanotube ink applied to the surface as the electrical conductor. We report on three experiments: the first one to characterize the conductive properties of the ECFs; the second one to investigate the fiber cytotoxic properties in vitro; and the third one to demonstrate the utility of the ECF for direct nerve stimulation in an in vivo rodent model.

Polyphenylenediethynylenes have been synthesized using copper(i) oxide nanocatalysts under ligandless conditions, mild base, and atmospheric air as the oxidant in good yield and number average molecular weight.

Very bright (≈14 000 cd m −2 ) deep blue exciplex organic light emitting diodes (OLEDs) peaking at ≈435 nm, where the photopic response is ≈0.033, and with CIE color coordinates (0.1525, 0.0820), are described. The OLED properties are interestingly linked to PPh 3 O (triphenylphosphine oxide) and attributes of the emitting layer (EML) comprising NPB interfacing host:guest TPBi:PPh 3 O 5:1 weight ratio. A neat PPh 3 O layer that is central for device performance follows the EML (NPB/TPBi:PPh 3 O 5:1/PPh 3 O). The bright electroluminescence originates from NPB/TPBi:PPh 3 O exciplexes involving triplets via thermally activated delayed fluorescence, as evident from the strong quenching of the photoluminescence (PL) by oxygen and interestingly, the monomolecular emission process. The transient PL decay times of a NPB/TPBi:PPh 3 O 5:1/PPh 3 O film are 43 ns in air versus 136, 610, and weak ≈2000 ns in N 2 . For comparison, the respective PL decay times of films of NPB:TPBi are 16 ns in air versus 131 and 600 ns in N 2 , and of NPB:PPh 3 O they are 29 ns in air versus 56, 483, and weak ≈2000 ns in N 2 . It is suspected that slow emitting states are associated with a PPh 3 O aggregate interacting with NPB.

Valuing diversity leads to scientific excellence, the progress of science and, most importantly, it is simply the right thing to do. We must value diversity not only in words, but also in actions.

The self-image that we project to others is a profound statement of who we want others to believe we are, particularly now, when so many meetings and gatherings are virtual. In recent history, people have become bolder in their self-image choices. The hair, for example, is a fantastic medium to make a statement of one’s narrative. The color of one’s hair can speak volumes. The current global hair dye and color industry’s market value is around 30 billion US dollars and projected to be about 42 billion US dollars by 2025. However, this market lacks diversity in its natural options of deep, dark pigments and dyes. There is also a deep concern over the toxicity of many hair-dyeing agents. The challenge to develop more nontoxic, mild, and biocompatible pathways for dyeing hair is ongoing. While henna is a natural plant-based pigment that has been used in many cultures for dyeing hair and creating body art, it is limited to the red color spectrum. Battistella et al. more recently reported a novel, bioinspired, and nontoxic approach to hair pigmentation.