Macromolecular Research最新文献

The growing demand for natural products in the cosmetic industry has led to increased interest in natural polysaccharides that offer biocompatibility, biodegradability, and bioactivity. Microorganisms have emerged as a promising source for large-scale production of these polysaccharides under controlled conditions. Among them, the halophilic bacterium Chromohalobacter canadensis 28 stands out as it produces an exopolymer (Cc EP) consisting of exopolysaccharides (EPS) and poly-gamma-glutamic acid (γ-PGA), making it the first halophilic microorganism known for PGA production. This study explores the potential of crude Cc EP and purified γ-PGA for improving the skin barrier, stimulating collagen and hyaluronic acid production, and facilitating wound closure. Through in-vitro experiments using human epidermal keratinocyte cells (HaCaT) and dermal fibroblast cells (PCS-201-012), both the exopolymers were found to exhibit positive effects on cellular proliferation and the expression of genes related to collagen, hyaluronic acid, involucrin, and filaggrin. Furthermore, in-vitro scratch models demonstrated their ability to enhance wound closure. Based on these promising findings, we propose that Cc EP and purified γ-PGA hold potential as active ingredients in cosmeceutical products. Their ability to promote cell proliferation, improve collagen and hyaluronic acid expression, and enhance wound closure makes them valuable assets for skincare applications.

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Production and effect of Chromohalobacter canadensis 28 exopolymer on human skin cells

The grafting of N-(4-hydroxyphenyl)-3,4,9,10-perylenetetracarboxylic-3,4-anhydride-9,10-imide (4) and N-(4-hydroxyphenyl)-1,4,5,8-naphthalenetetracarboxylic-1,8-anhydride-4,5-imide (8) onto low-molecular-weight chitosan (5) was performed. The fluorescence, stability, electroactivity, conductivity, and solubility properties of the grafted chitosan polymer 9 were highly enhanced compared to the original chitosan. The weight-average molecular weight (M_w) of 19,800 g/mol was obtained. Grafted chitosan has even more excellent thermal stability with a higher initial decomposition temperature of 285 °C and char yield at 900 °C up to 73%. The fluorescence quantum yield efficiencies for polymer 9 are very high in all studied solvents (70% in CH₃CN). The polymer showed five stepwise, fast, reversible one-electron reductions in electrochemical investigations due to the conductive fluorophores 4 and 8. The HOMO/LUMO levels were calculated as − 5.56 and − 4.14 eV, corresponding to the low band gap of 1.42 eV. The spectroelectrochemistry investigations confirmed the nature of the electron transfers. The morphological characterization using AFM, SEM, and TEM methods indicated a highly crystalline character of the grafted chitosan. The modified chitosan has the potential to be applied in various organic photonics and as a significant substrate material.

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Grafted chitosan polymers combining high crystalline character and excellent fluorescence, electroactivity and conductivity are promising candidates for photonic applications

In this work, new pH-sensitive hexagonal boron nitride–polysaccharides nanosystems were produced using sol–gel method. These hybrid sol–gel systems include β-cyclodextrin (β-CD), dextrin (Dex), shellac wax (Wax), and polyethylene glycol which were synthesized with hexagonal boron nitride (h-BN) by coupling of triethyl orthosilicate and donepezil. The release studies of DNP from each sol–gel systems were studied using buffers at various pH levels such as 2.2, 4.0, 6.0, 7.4, and 8.6. The release percentages of the drug were calculated by regression equations of the DNP which has maximum fluorescence intensity at 325 and 387 nm excitation and emission wavelengths. These new sol–gel hexagonal boron nitride systems were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, and scanning electron microscopy analysis. According to the results. The sol–gel systems with polysaccharide-based dextrin (h-BN–Dex) and shellac wax (h-BN–Wax) were more available at a pH levels of 6, 7.4, and 8.6 for the release of DNP.

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Thermoplastic polyurethane (TPU) has been widely utilized in varied fields due to their excellent properties such as flexibility, stretchability, thermal stability, resilience, etc. However, it is relatively difficult to control their properties comparing to PU because most of TPU properties are decided in synthetic level. Herein, aromatic polyols were introduced into desired TPU in synthetic level to overcome the issue and improve mechanical properties of TPU. Furthermore, the optimization condition is suggested by controlling the molar ratio of aliphatic/aromatic polyols. Finally, porous TPU sheets were fabricated via VIPS method using synthesized TPU. Tensile and compression testing were executed to compare the mechanical properties of each TPU and porous TPU sheet according to the molar ratio of aliphatic/aromatic polyols.

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The structure of thermoplastic polyurethane synthesized from aliphatic & aromatic polyols with the appearance of each segment in a molecule

The development of smart materials with reversible thermochromic properties is of great importance in the fields of sensors, displays and anticounterfeitings. In this article, a diacetylene monomer (AQDA) containing aminoquinoline as a head group was synthesized. Together with fluorescein-substituted diacetylene (FDA) and 10,12-pentacosadiynoic acid (PCDA), hybrid PDA vesicles were obtained through self-assembly and topochemical polymerization process. The hybrid PDA vesicles (FDA, AQDA and PCDA with molar ratio of 7:2:1) display an partially reversible green-to-orange red colorimetric change in a wider temperature range from 20 to 100 °C focusing on the stronger hydrogen bonding and aromatic interactions. This work may provide fundamental understanding of the mechanism and strategies for the design of reversible thermochromic PDA materials.

Graphical Abstract

A PDA derivative aminoquinoline-substituted polydiacetylene (AQDA) was introduced and it displays an intriguing reversible thermochromism with a green-to-orange red color transition at a wider temperature range from 20-100 oC in solution by the strong hydrogen bonding and aromatic interactions of the headgroups.

In this study, we added a small amount of polycarbonate (PC), ranging from 1 to 9 wt%, to the composites of styrene–acrylonitrile copolymer (SAN) and multiwalled carbon nanotube (MWNT). When two types of SANs having 24 and 32 wt% AN (SAN24 and SAN32) were used, we found that the resistivity of the SAN/MWNT (0.5 wt%) composites significantly decreased with the addition of 1–3% of PC, and the effect was more pronounced in the case of SAN32. Transmission electron microscopy (TEM) images revealed that MWNTs, which were uniformly distributed on the pure SAN, tended to agglomerate and form an interconnected structure when an appropriate amount of PC was added. The reduced resistivity of the composites is mainly attributed to the connectivity of MWNTs facilitating electron transport. It is worth noting that the network structure disappears when the amount of PC exceeds 5 wt%, where the size of PC domains grows, and most of the MWNTs are entrapped in the PC phase, resulting in an increased resistivity of the composite. The rheological investigation of the composites revealed that the storage moduli of the composites were sensitive to the state of MWNT distribution, which was greatly altered by the type of SAN and the amount of PC.

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Alteration of carbon nanotubes distribution in styrene–acrylonitrile due to the introduction of polycarbonate

Pseudo-protein is a novel synthetic biodegradeable material that has amino acids as the basic structural unit. Unlike protein, this polymer has other linking groups in addition to peptide bonds in their structure, which provide not only the excellent properties of protein, but also good mechanical properties, thermal properties, adjustable physicochemical properties, excellent cytocompatibility, 3D microporous structure, etc. Therefore, pseudo-proteins can be effectively applied in carriers, wound healing, tissue engineering, etc. This review summarizes the recent advances in the development of pseudo-proteins, the main classifications and the synthetic methods used in their preparation along with their main applications.

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In this study, we developed macrophage-derived nanovesicles (MNVs) to specifically target tumor cells. Initially, we chemically coupled hyaluronic acid (HA) with 3-(diethylamino)propylamine (DEAP; with a pK_b value of approximately 7.0) to confer pH-responsive properties. The resulting polymer (HDEA) and chlorin e6 (Ce6, serving as a photosensitizing model drug) were incorporated into MNVs using a sonication process, resulting in Ce6-loaded HDEA@MNVs. Our experiments demonstrated that the integrin α4β1 expressed in MNVs selectively interacted with vascular cell adhesion molecule-1 (VCAM-1) in SK-N-MC tumor cells, leading to enhanced accumulation of MNVs within the tumor cells. Consequently, HDEA@MNVs exhibited significant accumulation within tumor cells, underwent structural destabilization at endosomal pH due to the protonation of pH-responsive DEAP within the HDEA@MNVs, and facilitated the release of Ce6. The released free Ce6 from MNVs exhibited improved effectiveness in photodynamic tumor therapy when exposed to laser irradiation. In vitro cell experiments demonstrated efficient internalization of HDEA@MNVs into tumor cells and high efficacy in photodynamic therapy.

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Wastewater from industrial sources varies greatly in composition. Separating and recycling these waste remains challenging. The efficacy of nanofiber membranes in separating binary liquids has been demonstrated, which in this work we extend to the separation of ternary liquids. Polyvinylidene fluoride (PVDF) nanofiber membranes with different surface tensions were fabricated by electrospinning and surface coating. Membranes made from polyvinyl alcohol and polyacrylic acid (PVA-PAA), and PVDF nanofiber membranes were used in combination for separating water and oils. And pure PVDF and PVDF membranes coated with tetraethyl orthosilicate and decyltrimethoxysilane (TEOS/DTMS) were used together to separate different oils. The structural parameters of PVDF nanofiber membranes, e.g., pore size, thickness, and porosity were easily adjusted to achieve high flux and separation efficiency. For example, the average separation efficiencies for water, oleic acid, and silicon oil were 99.21%, 94.45%, and 84.61%, respectively. Finally, using a two-step setup, a ternary liquid mixture of water, oleic acid, and silicon oil was efficiently separated, which shows great promise for addressing the problem of separating wastewater with mixed compositions.

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Schematic illustration of wettability relationship of PVDF membrane

The objective of the present study was to develop a W/O/W nanoemulsion (NE) drug delivery system loaded with punicalagin (PGN) for oral delivery and evaluate its potential in antibacterial therapy. The W/O/W PGN-NE was prepared using a two-step process by combining ultrasonic with high-energy emulsification and subsequently characterized by its droplet size, zeta potential, and morphology. The PGN-NE was further evaluated for its pH, in vitro antibacterial activity, drug release property, and cytotoxicity. The results indicated the formation of spherical, nano-sized globules of PGN-NE had a mean particle size of 45.53 ± 2.2 nm, with a PDI value of 0.22 ± 0.028, zeta potential was −4.67 ± 0.88 mV, and pH value was 5.8. In vitro antibacterial activity studies showed a significantly higher antibacterial activity of PGN-NE in comparison to free PGN, suggesting that NE can effectively improve the antibacterial effect of natural pharmaceuticals. The drug release assay demonstrated that PGN was slowly released from the NE preparation and absorbed, helping to prolong the potency and improve the bioavailability of PGN. Cytotoxicity testing showed that PGN had reduced toxicity when encapsulated in NE. Thus, the developed NE formulation of PNG exhibited a greater potential for the slow-release effect delivery and in the treatment of microbial infections with favorable safety profile.

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Micromorphology of W/O/W PGN nanoemulsion

The W/O/W PGN-NE are uniform in size and non-adhesive, with a size distribution of 28.214 to 141.772 nm and a mean size of 45.53 ± 2.2 nm, respectively, with a PDI value of 0.22 ± 0.028.