Lignin and functional polymer-based materials: Synthesis, characterization and application for Cr (VI) and As (V) removal from aqueous media.

In this study, lignin derived from corncobs was chemically modified by substituting the hydroxyl groups present in its structure with methacrylate groups through a catalytic reaction using methacrylic anhydride, resulting in methacrylated lignin (ML). These MLs were incorporated in polymerization reaction of the monomer 2-[(acryloyloxy)ethyl trimethylammonium] chloride (Cl-AETA) and Cl-AETA, Cl-AETA/ML polymers were obtained, characterized (spectroscopic, thermal and microscopic analysis), and evaluated for removing Cr (VI) and As (V) from aqueous media in function of pH, contact time, initial metal concentrations and adsorbent amount. The Cl-AETA/ML polymers followed the Langmuir adsorption model for the evaluated metal anions and were able to remove up to 91 % of Cr (VI) with a qmax (maximum adsorption capacity) of 201 mg/g, while for As (V), up to 60 % could be removed with a qmax of 58 mg/g. The results demonstrate that simple modifications in lignin enhance its functionalization and properties, making it suitable for removing contaminants from aqueous media, showing promising results for potential future applications.

A novel XYZ electrospinning that orients the trajectory and collimates the electrified fluid jet of polymer nanofibers by induced electric fields.

Electrospinning is a process in which high voltage creates nanostructured fibers with random orientation from a polymer solution. A novel electrospinning instrument was designed and constructed, capable of orienting and collimating the trajectory of the electrified fluid jet. The equipment collimates and adjusts the electrified fluid jet in the X-Y directions using deflector plates connected to a variable electric field. Simultaneously, different membrane thicknesses can be selected, i.e., in the Z direction. Additionally, by programming the sinusoidal function generator to perform an X-Y sweep, Lissajous figures (LF) were obtained. SEM images obtained through XYZ electrospinning of PVC and PVDF membranes were used to determine the control achieved over the orientation distribution of the processed nanofibers and the modification of their diameter, with and without applying the electric field to the deflector plates. The nanofibers obtained from the polymeric membranes, which originated after the straight segment of the Taylor cone, did not exhibit a random trajectory and position. Instead, the collimated electrified fluid jet deposited them in a cross pattern (X-Y) on the collector-cathode plate.

Comportamiento orgánico en la utilización de barreras con polímeros impresos 3D para la regeneración ósea guiada en implantología / Organic behavior in the utilization of barriers with 3D printed polymers for guided bone regeneration in implantology

Este estudio aborda la viabilidad y los retos inherentes al uso de barreras de polímeros impresos en 3D para la regeneración ósea guiada (en adelante, ROG) en procedimientos de implantología dental. A través del análisis exhaustivo de investigaciones y aplicaciones clínicas actuales, se evalúa detalladamente la biocompatibilidad, la funcionalidad estructural y las respuestas biológicas inducidas por estas barreras innovadoras en entornos terapéuticos. Este enfoque permite una comprensión más profunda de las interacciones osteointegrativas y las perspectivas de adaptabilidad tisular asociadas con materiales poliméricos avanzados (AU)

This scholarly investigation delineates the efficacy and inherent challenges of utilizing 3D printed polymer barriers for guided bone regeneration (GBR) in dental implantology procedures. An extensive review of current research and clinical implementations provides a critical assessment of biocompatibility, structural functionality, and the biological responses elicited by these innovative barriers within therapeutic contexts. The study delves into the osteointegrative interactions and tissue adaptability prospects facilitated by advanced polymeric materials, offering significant insights into their clinical utility.(AU)

Plastic-degrading microbial communities reveal novel microorganisms, pathways, and biocatalysts for polymer degradation and bioplastic production.

Plastics derived from fossil fuels are used ubiquitously owing to their exceptional physicochemical characteristics. However, the extensive and short-term use of plastics has caused environmental challenges. The biotechnological plastic conversion can help address the challenges related to plastic pollution, offering sustainable alternatives that can operate using bioeconomic concepts and promote socioeconomic benefits. In this context, using soil from a plastic-contaminated landfill, two consortia were established (ConsPlastic-A and -B) displaying versatility in developing and consuming polyethylene or polyethylene terephthalate as the carbon source of nutrition. The ConsPlastic-A and -B metagenomic sequencing, taxonomic profiling, and the reconstruction of 79 draft bacterial genomes significantly expanded the knowledge of plastic-degrading microorganisms and enzymes, disclosing novel taxonomic groups associated with polymer degradation. The microbial consortium was utilized to obtain a novel Pseudomonas putida strain (BR4), presenting a striking metabolic arsenal for aromatic compound degradation and assimilation, confirmed by genomic analyses. The BR4 displays the inherent capacity to degrade polyethylene terephthalate (PET) and produce polyhydroxybutyrate (PHB) containing hydroxyvalerate (HV) units that contribute to enhanced copolymer properties, such as increased flexibility and resistance to breakage, compared with pure PHB. Therefore, BR4 is a promising strain for developing a bioconsolidated plastic depolymerization and upcycling process. Collectively, our study provides insights that may extend beyond the artificial ecosystems established during our experiments and supports future strategies for effectively decomposing and valorizing plastic waste. Furthermore, the functional genomic analysis described herein serves as a valuable guide for elucidating the genetic potential of microbial communities and microorganisms in plastic deconstruction and upcycling.

Evaluation of in vivo and in vitro efficacy of solasonine/solamargine-loaded lipid-polymer hybrid nanoparticles against bladder cancer.

Solasonine (SS) and solamargine (SM) are alkaloids known for their antioxidant and anticancer properties, which can be further enhanced by encapsulating them in nanoparticles. This led to a study on the potential therapeutic benefits of SS and SM against bladder cancer when encapsulated in lipid-polymer hybrid nanoparticles (LPHNP). The LPHNP loaded with SS/SM were prepared using the emulsion and sonication method and their physical-chemical properties characterized. The biological effects of these nanoparticles were then tested in both 2D and 3D bladder cancer cell culture models, as well as in a syngeneic orthotopic mouse model based on the MB49 cell line and ethanol epithelial injury. The LPHNP-SS/SM had an average size of 130 nm, a polydispersity index of 0.22 and a positive zeta potential, indicating the presence of chitosan coating on the nanoparticle surface. The dispersion of LPHNP-SS/SM was found to be monodispersed with a span index of 0.539, as measured by nanoparticle tracking analysis (NTA). The recrystallization index, calculated from DSC data, was higher for the LPHNP-SS/SM compared to LPHNPs alone, confirming the presence of alkaloids within the lipid matrix. The encapsulation efficiency (EE%) was also high, with 91.08 % for SS and 88.35 % for SM. Morphological analysis by AFM and Cryo-TEM revealed that the nanoparticles had a spherical shape and core-shell structure. The study showed that the LPHNP-SS/SM exhibited mucoadhesive properties by physically interacting with mucin, suggesting a potential improvement in interaction with mucous membrane. Both the free and nanoencapsulated SS/SM demonstrated dose-dependent cytotoxicity against bladder cancer cell lines after 24 and 72 h of treatment. In 3D bladder cell culture, the nanoencapsulated SS/SM showed an IC50 two-fold lower than free SS/SM. In vivo studies, the LPHNP-SS/SM displayed an antitumoral effect at high doses, leading to a significant reduction in bladder volume compared to the positive control. However, there were observed instances of systemic toxicity and liver damage, indicated by elevated levels of transaminases (TGO and TGP). Overall, these results indicate that the LPHNPs effectively encapsulated SS/SM, showing high encapsulation efficiency and stability, along with promising in vitro and in vivo antitumoral effects against bladder cancer. Further evaluation of its systemic toxicity effects is necessary to ensure its safety and efficacy for potential clinical application.

In Vitro Comparison of Titanium Disc Surface Roughness and Bacterial Colonization After Ultrasonic Instrumentation With Three Different Tips.

During implant maintenance, preserving a smooth surface on the machined transmucosal abutment is critical to reduce biofilm attachment and colonization. The present study compared the surface roughness and bacterial colonization of machined titanium surfaces after instrumentation with various materials. Forty-four machined grade 23 titanium discs were instrumented with a round polyether ether ketone (PEEK) tip, a plastic curette tip, or a pure titanium curette tip with piezoelectric devices. Before and after instrumentation, the surface roughness (Ra and Rz) values were analyzed with a profilometer and scanning electron microscopy (SEM). Streptococcus sanguinis was cultured and incubated for 24 hours on the instrumented discs, and colony-forming units per milliliter were obtained for each group. Samples instrumented with the metal ultrasonic tip significantly increased surface roughness compared with the other groups. This resulted in greater colonization by S. sanguinis than surfaces instrumented with PEEK tips or the negative control. Samples instrumented with PEEK and plastic tips did not exhibit any statistically significant increase in surface roughness, and SEM analysis revealed a significantly rougher surface of discs instrumented with metal compared with discs instrumented with plastic or PEEK tips despite the possibility of debris from tip dissolution. Our results suggest that instrumentation with metal ultrasonic tips with piezoelectric devices significantly increased machined titanium's surface roughness and elicited higher biofilm formation in vitro. Meanwhile, instrumentation of machined titanium with PEEK or plastic ultrasonic tips did not affect the surface roughness or bacterial adhesion.

Rational design of solid lipid-polymer hybrid nanoparticles: An innovative glycoalkaloids-carrier with potential for topical melanoma treatment.

Despite the promising potential of Solanum plant glycoalkaloids in combating skin cancer, their clinical trials have been halted due to dose-dependent toxicity and poor water solubility. In this study, we present a rational approach to address these limitations and ensure colloidal stability of the nanoformulation over time by designing solid lipid-polymer hybrid nanoparticles (SLPH). Leveraging the biocompatible and cationic properties of polyaspartamides, we employed a new polyaspartamide derivative (P1) as a raw material for this class of nanostructures. Subsequently, we prepared SLPH through a one-step process involving hot-melt emulsification followed by ultrasonication. The physicochemical properties of the SLPH were thoroughly characterized using dynamic light scattering (DLS), ζ-potential analysis, nanoparticle tracking analysis (NTA), differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM). The optimized formulation exhibited long-term stability over six months under low temperatures, maintaining a particle size around 200 nm, a polydispersity index (PdI) lower than 0.2, and a ζ-potential between +35-40 mV. Furthermore, we evaluated the cytotoxic effect of the SLPH against human cutaneous melanoma cells (SK-MEL-28) compared to human foreskin fibroblast cells (HFF-1). Encapsulation of glycoalkaloids into the nanoparticles (SLPH-GE) resulted in a two-fold greater selective cytotoxic profile for melanoma cells than glycoalkaloids-free (GE). The nanoparticles disrupted the stratum corneum barrier with a penetration depth of approximately 77 µm. These findings underscore the potential of the developed nanosystem as an effective glycoalkaloid carrier with suitable colloidal and biological properties for further studies in topical treatment strategies for cutaneous melanoma.

Sodium lignosulfonate as an extracting agent of methylene blue dye using a polymer-enhanced ultrafiltration technique.

The purpose of this research was to evaluate the efficacy of sodium lignosulfonate (LS) as a dye adsorbent in the removal of methylene blue (MB) from water by polymer-enhanced ultrafiltration. Various parameters were evaluated, such as membrane molecular weight cut-off, pH, LS dose, MB concentration, applied pressure, and the effect of interfering ions. The results showed that the use of LS generated a significant increase in MB removal, reaching an elimination of up to 98.0 % with 50.0 mg LS and 100 mg L-1 MB. The maximum MB removal capacity was 21 g g-1 using the enrichment method. In addition, LS was reusable for up to four consecutive cycles of dye removal-elution. The removal test in a simulated liquid industrial waste from the textile industry was also effective, with a MB removal of 97.2 %. These findings indicate that LS is highly effective in removing high concentrations of MB dye, suggesting new prospects for its application in water treatment processes.

In vitro antifungal activity of polymeric nanoparticles loaded with Euphorbia tirucalli extract.

The therapeutic potential of medicinal plants is known as an alternative in treatment of human affections; in effect, the conventional application of these medicinal sources has several limitations like low bioavailability, solubility and stability, which affect its pharmacological efficacy. In recent decades, extraordinary advances have been made in new drug delivery systems using nanocarriers. This work consisted in determining the in vitro antifungal activity of the methanolic extract of Euphorbia tirucalli formulated in polymeric nanoparticles. The antifungal activity was determined by the microdilution method in 96-well microplates, applying nanoparticles loaded with plant extract (NP-Ext) obtained by nanoprecipitation on clinical isolates of Trichophyton rubrum and T. interdigitalis. Regarding the nanoparticles, the lots used did not present significant differences in their physicochemical characteristics, with a size of 91.885 ± 1.621nm, polydispersity index of 0.152 ± 0.025 and Z-potential of -6.047 ± 0.987. The quantification of the extract in the polymeric matrix was determined by infrared spectroscopy (FTIR), where an efficiency and encapsulation percentage of 22.15 ± 0.82 and 2.95 ± 0.11, respectively, were obtained. The in vitro antifungal activity of the crude and formulated extract was obtained calculating the Minimum Inhibitory Concentration (MIC) of each one; a MIC of 125 µg/mL was obtained against T. rubrum and T. interdigitalis with the crude extract, while a MIC value of 55.55 and 0.1 µg/mL was obtained with NP-Ext, respectively, against these same. Conclusions: biological activity is closely linked to the phytochemical profile of the extract; while the improvement of said potential with the NP-Ext with the dosage form was directly related to the physicochemical characteristics of the nanocarrier.

Electrochemical sensing at the fingertips: Wearable glove-based sensors for detection of 4-nitrophenol, picric acid and diazepam.

A wearable glove-based sensor is a portable and practical approach for onsite detection/monitoring of a variety of chemical threats. Herein, we report a flexible and sensitive wearable sensor fabricated on the nitrile glove fingertips by stencil-printing technique. The working electrodes were modified with multiwalled carbon nanotubes (MWCNTs)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) for sensitive and real-time analyses of hazardous or chemical treats, as picric acid (PA) explosive, diazepam (DZ) as drug-facilitated crimes and the emerging pollutant 4-nitrophenol (4-NP). The multi-sensing platform towards PA, 4-NP, and DZ offers the ability of in-situ qualitative and quantitative analyses of powder and liquid samples. A simple sampling by touching or swiping the fingertip sensor on the sample or surface under investigation using an ionic hydrogel combined with fast voltammetry measurement provides timely point-of-need analyses. The wearable glove-based sensor uses the square wave voltammetry (SWV) technique and exhibited excellent performance to detect PA, 4-NP, and DZ, resulting in limits of detection (LOD) of 0.24 µM, 0.35 µM, 0.06 µM, respectively, in a wide concentration range (from 0.5 µM to 100 µM). Also, we obtained excellent manufacturing reproducibility with relative standard deviations (RSD) in the range of 3.65%-4.61% using 7 different wearable devices (n = 7) and stability in the range of 4.86%-6.61% using different electrodes stored for 10 days at room temperature (n = 10), demonstrating the excellent sensor-to-sensor reproducibility and stability for reliable in-field measurements. The stretchable sensor presented great mechanical robustness, supporting up to 80 bending or stretching deformation cycles without significant voltammetric changes. Collectively, our wearable glove-based sensor may be employed for analyses of chemical contaminants of concern, such as explosives (PA), drugs (DZ), and emerging pollutants (4-NP), helping in environmental and public safety control.

Bioadhesive Polymeric Films Containing Rhamnolipids, An Innovative Antimicrobial Topical Formulation.

Acne affects most of the world's population, causing an impact on the self-esteem of adolescents and young adults. One of the causes is the presence of the bacteria Cutibacterium acnes which are part of the natural microbiota of the skin. Topical treatments consist of anti-inflammatory and antibiotics, which could select resistant strains. Alternatives to the antibiotic are biocomposites that have antimicrobial activity like biosurfactants which are produced by bacteria. An innovative way of applying these compounds is bioadhesive polymeric films that adhere to the skin and release the active principle topically. Rhamnolipids have great potential to be used in the treatment of acne because they present antimicrobial activity against C. acnes in low and safe concentrations (MIC of 15.62 µg/mL, CBM of 31.25 µg/mL and CC50 of 181.93 µg/mL). Four films with different rhamnolipids concentrations (0.0; 0.1; 0.2; and 0.3%, w/w) were obtained as to visual appearance, mass variation, thickness, density, solubility, pH, water vapor transmission, mechanical properties (folding endurance, bioadhesion strength, tensile strength, elongation at break and Young's modulus), scanning electron microscopy and infrared. The results show that these formulations had a homogeneous appearance; elastic mechanical properties; pH similar to human skin and bioadhesive. The polymeric films containing rhamnolipids were effective against C. acnes, in the in vitro test, at the three concentrations tested, the film with the highest concentration (0.3%, w/w) being the most promising for presenting the highest antimicrobial activity. Thus, the polymeric film containing rhamnolipids has the potential to be used in the treatment of acne.

Exploring Maillard reaction markers and melanoidins to investigate toxicological and antioxidant profiles of optimized expanded snacks from corn/common bean mixtures.

BACKGROUND: Extrusion cooking of cereal-legume flour mixture is an innovative strategy to introduce nutrient-enriched ready-to-eat snacks to the market. However, this thermal process triggers the formation of compounds that could impact safety aspects of these products. Maillard reaction markers and the end products known as melanoidins were evaluated to assess the toxicological and bioactive profiles of extruded snacks from corn-plus-common-bean-flour combinations. Different molecular weight fractions were isolated and purified to analyze their antioxidant activity and to investigate the role of melanoidins. RESULTS: The snack formulated with an 84:16 ratio of corn:common bean flours exhibited an enhanced toxicological profile. It displayed the lowest levels of acrylamide and furanic compounds, along with reduced blockage of lysine residues in the protein. Extrusion increased the antioxidant activity of uncooked flours (30 to 64%) and total phenolic compounds (26 to 50%), and decreased the available lysine (-72.7 to -79.5%). During the fractionation process, it was established that compounds within the range of 3-10 kDa made the greatest contribution to antioxidant activity. The fraction greater than 10 kDa, which included melanoidins, displayed 7 to 33% lower antioxidant activity. The purification of the fraction greater than 10 kDa revealed that pure melanoidins represented approximately one-third of the antioxidant activity in that fraction. Non-covalent adducts linked to the melanoidin core therefore had a relevant role in the antioxidant action of formulated snacks. CONCLUSION: This investigation illustrates the importance of considering both potential risks and associated benefits of compounds formed during the Maillard reaction while developing new extruded snacks. © 2024 The Author(s). Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Multifactorial evaluation of an ultra-fast process for electrospinning of recycled expanded polystyrene to manufacture high-efficiency membranes for nanoparticle air filtration.

The increased production of polystyrene waste has led to the need to find efficient ways to dispose of it. One possibility is the use of solid waste to produce filter media by the electrospinning technique. The aim of this work was to develop an ultra-fast electrospinning process applied to recycled polystyrene, with statistical evaluation of the influence of polymeric solution parameters (polymer concentration and percentage of DL-limonene) and process variables (flow rate, voltage, and type of support) on nanoparticle collection efficiency, air permeability, and fiber diameter. An extensive characterization of the materials and evaluation of the morphology of the fibers was also carried out. It was found that recycled expanded polystyrene could be used in electrospinning to produce polymeric membranes. The optimized condition that resulted in the highest nanoparticle collection efficiency was a polymer concentration of 13.5%, percentage of DL-limonene of 50%, voltage of 25 kV, and flow rate of 1.2 mL/h, resulting in values of 99.97 ± 0.01%, 2.6 ± 0.5 × 10-13 m2, 0.19 Pa-1, and 708 ± 176 nm for the collection efficiency of nanoparticles in the range from 6.38 to 232.9 nm, permeability, quality factor, and mean fiber diameter, respectively. All the parameters were found to influence collection efficiency and fiber diameter. The use of DL-limonene, a natural solvent, provided benefits including increased collection efficiency and decreased fiber size. In addition, the electrostatic filtration mechanism was evaluated using the presence of a copper grid as a support for the nanofibers. The findings demonstrated that an electrospinning time of only 5 min was sufficient to obtain filters with high collection efficiencies and low pressure drops, opening perspectives for the application of polystyrene waste in the development of materials with excellent characteristics for application in the area of atmospheric pollution mitigation.

Multivariate Analysis of Solubility Parameters for Drug-Polymer Miscibility Assessment in Preparing Raloxifene Hydrochloride Amorphous Solid Dispersions.

The success of obtaining solid dispersions for solubility improvement invariably depends on the miscibility of the drug and polymeric carriers. This study aimed to categorize and select polymeric carriers via the classical group contribution method using the multivariate analysis of the calculated solubility parameter of RX-HCl. The total, partial, and derivate parameters for RX-HCl were calculated. The data were compared with the results of excipients (N = 36), and a hierarchical clustering analysis was further performed. Solid dispersions of selected polymers in different drug loads were produced using solvent casting and characterized via X-ray diffraction, infrared spectroscopy and scanning electron microscopy. RX-HCl presented a Hansen solubility parameter (HSP) of 23.52 MPa1/2. The exploratory analysis of HSP and relative energy difference (RED) elicited a classification for miscible (n = 11), partially miscible (n = 15), and immiscible (n = 10) combinations. The experimental validation followed by a principal component regression exhibited a significant correlation between the crystallinity reduction and calculated parameters, whereas the spectroscopic evaluation highlighted the hydrogen-bonding contribution towards amorphization. The systematic approach presented a high discrimination ability, contributing to optimal excipient selection for the obtention of solid solutions of RX-HCl.

The role of artificial intelligence and data science in nanoparticles development: a review.

Artificial intelligence has revolutionized many sectors with unparalleled predictive capabilities supported by machine learning (ML). So far, this tool has not been able to provide the same level of development in pharmaceutical nanotechnology. This review discusses the current data science methodologies related to polymeric drug-loaded nanoparticle production from an innovative multidisciplinary perspective while considering the strictest data science practices. Several methodological and data interpretation flaws were identified by analyzing the few qualified ML studies. Most issues lie in following appropriate analysis steps, such as cross-validation, balancing data, or testing alternative models. Thus, better-planned studies following the recommended data science analysis steps along with adequate numbers of experiments would change the current landscape, allowing the exploration of the full potential of ML.

[Box: see text].

Adsorptive features of cyclohexane carboxylic naphthenic acid on a novel cross-linked polymer developed from spent coffee grounds.

Naphthenic acids (NA) are organic compounds commonly found in crude oil and produced water, known for their recalcitrance and toxicity. This study introduces a new adsorbent, a polymer derived from spent coffee grounds (SCGs), through a straightforward cross-linking method for removing cyclohexane carboxylic acid as representative NA. The adsorption kinetics followed a pseudo-second-order model for the data (0.007 g min-1 mg-1), while the equilibrium data fitted the Sips model ( q m = 140.55 mg g-1). The process's thermodynamics indicated that the target NA's adsorption was spontaneous and exothermic. The localized sterical and energetic aspects were investigated through statistical physical modeling, which corroborated that the adsorption occurred indeed in monolayer, as suggested by the Sips model, but revealed the contribution of two energies per site ( n 1 ; n 2 ). The number of molecules adsorbed per site ( n ) was highly influenced by the temperature as n 1 decreased with increasing temperature and n 2 increased. These results were experimentally demonstrated within the pH range between 4 and 6, where both C6H11COO-(aq.) and C6H11COOH(aq.) species coexisted and were adsorbed by different energy sites. The polymer produced was naturally porous and amorphous, with a low surface area of 20 to 30 m2 g-1 that presented more energetically accessible sites than other adsorbents with much higher surface areas. Thus, this study shows that the relation between surface area and high adsorption efficiency depends on the compatibility between the energetic states of the receptor sites, the speciation of the adsorbate molecules, and the temperature range studied.

Evaluation of polymersome permeability as a fundamental aspect towards the development of artificial cells and nanofactories.

Polymersomes are synthetic vesicles with potential use in healthcare, chemical transformations in confined environment (nanofactories), and in the construction of artificial cells and organelles. In this framework, one of the most important features of such supramolecular structures is the permeability behavior allowing for selective control of mass exchange between the inner and outer compartments. The use of biological and synthetic nanopores in this regard is the most common strategy to impart permeability nevertheless, this typically requires fairly complex strategies to enable porosity. Yet, investigations concerning the permeability of polymer vesicles to different analytes still requires further exploration and, taking these considerations into account, we have detailed investigated the permeability behavior of a variety of polymersomes with regard to different analytes (water, protons, and rhodamine B) which were selected as models for solvents, ions, and small molecules. Polymersomes based on hydrophilic blocks of poly[N-(2-hydroxypropyl)methacrylamide] (PHPMA) or PEO (poly(ethylene oxide)) linked to the non-responsive blocks poly[N-(4-isopropylphenylacetamide)ethyl methacrylate] (PPPhA) or poly(methyl methacrylate) (PMMA), or to the stimuli pH-responsive block poly[2-(diisopropylamino)ethyl methacrylate] (PDPA) have been investigated. Interestingly, the produced PEO-based vesicles are notably larger than the ones produced using PHPMA-containing block copolymers. The experimental results reveal that all the vesicles are inherently permeable to some extent with permeability behavior following exponential profiles. Nevertheless, polymersomes based on PMMA as the hydrophobic component were demonstrated to be the least permeable to the small molecule rhodamine B as well as to water. The synthetic vesicles based on the pH-responsive PDPA block exhibited restrictive and notably slow proton permeability as attributed to partial chain protonation upon acidification of the medium. The dye permeability was evidenced to be much slower than ion or solvent diffusion, and in the case of pH-responsive assemblies, it was demonstrated to also depend on the ionic strength of the environment. These findings are understood to be highly relevant towards polymer selection for the production of synthetic vesicles with selective and time-dependent permeability, and it may thus contribute in advancing biomimicry and nanomedicine.

Toxicological analysis of chronic exposure to polymeric nanocapsules with different coatings in Drosophila melanogaster.

Nanotechnology involves the utilization of nanomaterials, including polymeric nanocapsules (NCs) that are drug carriers. For modify drug release and stability, nanoformulations can feature different types of polymers as surface coatings: Polysorbate 80 (P80), Polyethylene glycol (PEG), Chitosan (CS) and Eudragit (EUD). Although nanoencapsulation aims to reduce side effects, these polymers can interact with living organisms, inducing events in the antioxidant system. Thus far, little has been described about the impacts of chronic exposure, with Drosophila melanogaster being an in vivo model for characterizing the toxicology of these polymers. This study analyzes the effects of chronic exposure to polymeric NCs with different coatings. Flies were exposed to 10, 50, 100, and 500 µL of NCP80, NCPEG, NCCS, or EUD. The survival rate, locomotor changes, oxidative stress markers, cell viability, and Nrf2 expression were evaluated. Between the coatings, NCPEG had minimal effects, as only 500 µL affected the levels of reactive species (RS) and the enzymatic activities of catalase (CAT) and glutathione S-transferase (GST) without reducing Nrf2 expression. However, NCEUD significantly impacted the total flies killed, RS, CAT, and Superoxide dismutase from 100 µL. In part, the toxicity mechanisms of these coatings can be explained by the imbalance of the antioxidant system. This research provided initial evidence on the chronic toxicology of these nanomaterials in D. melanogaster to clarify the nanosafety profile of these polymers in future nanoformulations. Further investigations are essential to characterize possible biochemical pathways involved in the toxicity of these polymeric coatings.

Biophysical investigation of liposome systems decorated with bioconjugated copolymers in the presence of amantadine.

Liposome-based technologies derived from lipids and polymers (e.g., PEGylated liposomes) have been recognized because of their applications in nanomedicine. However, since such systems represent myriad challenges and may promote immune responses, investigation of new biomaterials is mandatory. Here, we report on a biophysical investigation of liposomes decorated with bioconjugated copolymers in the presence (or absence) of amantadine (an antiviral medication). First, copolymers of poly(N,N-dimethylacrylamide-co-fluoresceinacrylate-co-acrylic acid-N-succinimide ester)-block-poly(N-isopropylacrylamide) (PDMA-b-PNIPAM) containing a fluorescence label were biofunctionalized with short peptides that resemble the sequence of the loops 220 and 130 of the binding receptor of the hemagglutinin (HA) protein of the influenza A virus. Then, the bioconjugated copolymers were self-assembled along with liposomes composed of 1,2 dimyristoyl-sn-glycero-3-phosphocholine, sphingomyelin, and cholesterol (MSC). These biohybrid systems, with and without amantadine, were systematically characterized using differential scanning calorimetry (DSC), dynamic light scattering (DLS), and cryogenic transmission electron microscopy (cryoTEM). Finally, the systems were tested in an in vitro study to evaluate cytotoxicity and direct immunofluorescence in Madin Darbin Canine Kidney (MDCK) cells. The biohybrid systems displayed long-term stability, thermo-responsiveness, hydrophilic-hydrophobic features, and fluorescence properties and were presumable endowed with cell targeting properties intrinsically integrated into the amino acid sequences of the utilized peptides, which indeed turn them into promising nanodevices for biomedical applications.