Macromolecular Chemistry and Physics最新文献

Conductive hydrogels possess excellent flexibility, conductivity, and sensing properties, making them important carrier materials for flexible strain sensors. They show promising application prospects in fields such as human motion detection and artificial intelligence. This paper introduces polyaniline (PANI) and glycerol (GL) into the magnesium acrylate (AMgA) monomer and prepares the polymagnesium acrylate/glycerol/polyaniline (PAMgA/GL/PANI) hydrogel by free radical polymerization method. When the addition of PANI is 9 wt.%, the PAMgA/GL/PANI hydrogel exhibits good mechanical properties, with a tensile strength of 0.385 MPa, an elongation at break of up to 505%, a compressive strength of 1.04 MPa, and its room temperature conductivity is 1.437 S m⁻¹. Even after freezing at −20 °C, its conductivity can still reach 1.254 S m⁻¹. When the tensile deformation of this conductive hydrogel reaches 500%, the gauge factor (GF) reaches 10.33. In addition, the PAMgA/GL/PANI hydrogel also has good self-healing, adhesion, and moisture retention. These excellent characteristics make it suitable as a flexible strain sensor that can not only accurately monitor human joint movements and subtle physiological signals but also serve as an encrypted information transmission medium.

Diabetic foot ulcer (DFU) is a very serious side effect among the diabetic patients with substantial clinical and economic consequences. The aim of this study was to investigate the efficacy of cows' milk topical ointment, as an available and cost-effective natural product, on accelerating the healing of DFU. In this randomized controlled clinical trial, patients with grade 1 or 2 DFU were randomly divided into two groups of intervention (n = 50) and control (n = 49). For patients of intervention group, cows' milk 20% topical ointment was applied on the ulcer once daily for two weeks, while a type of novel dressing was used for control group with the same frequency and duration. Both groups received usual standard wound care measures. The percentage of change in the ulcer size and the number of cases with complete wound healing (>90% reduction in the ulcer size) were recorded in the both groups. The ulcer size significantly reduced in both groups on the seventh and 14^th days of intervention; however, the percentage of reduction was significantly higher in the intervention (milk) group compared to control at both time points (44.64 ± 15.98 vs. 24.95 ± 12.78, P < .001; 67.67 ± 22.15 vs. 42.87 ± 19.74, P < .001). Furthermore, although more patients in the intervention group (n = 4, 8%) showed complete healing of the ulcer compared to control (n = 0), the difference was not statistically significant (P = .117). Cow's milk 20% topical ointment improves and accelerates the healing of diabetic foot ulcers. However, more clinical studies are required to confirm these effects.

The formulation as amorphous solid dispersion (ASD) addresses recent challenges in the oral administration of poorly-soluble drugs by embedding them in highly-soluble carrier polymers. In this context, utilizing CO₂ as a processing agent is an innovative strategy to facilitate the dissolution of the drug in the polymer at comparatively low temperatures without the use of any organic solvents. Within this study, the influence of CO₂ on the phase behavior of ASD formulations is investigated. Therefore, high-pressure differential scanning calorimetry is applied to evaluate the dissolution of the drugs in the polymers and the glass transition temperatures under CO₂ of four formulations containing the drugs acetaminophen and itraconazole as well as the polymers Soluplus and vinylpyrrolidone/vinyl acetate copolymer. The glass transition temperatures of the ASD formulations decrease with CO₂ fraction dissolved in the polymer. The extent of T_g reduction is related to the spatial structure and intermolecular interactions of the polymers. Furthermore, the sorption of CO₂ accelerates the diffusion of the drugs in the plasticized polymers. However, phase separation is observed in some formulations under CO₂ loading which has an impact on the stability of the ASD and has to be considered in process design.

As the field of theranostics expands, an imminent need arises for multifaceted polymer-based nanotechnologies for clinical application. In this work, reversible addition-fragmentation chain transfer (RAFT) aqueous emulsion polymerization is used to form ¹⁹F-containing amphiphilic hybrid block copolymers (HBCs). Employing a cationic dendritic macromolecular chain transfer agent (mCTA), polymer frameworks comprised of chemically distinctive blocks of differing architectures (i.e., dendritic and grafted/linear) are strategically designed and synthesized. In aqueous media, self-assembled polymer nanoparticles (PNPs) are formed. Their physicochemical properties and their potential as biomaterials for MRI applications are assessed. By showcasing a newly established mCTA and using these resulting PNPs as imaging probes, the work expands the design space of RAFT polymerization in biomedical research, paving the way for the development of more effective and versatile MRI imaging tools.

The effects of crystal nuclei or crystallization on the isothermal crystallization behavior of isotactic polypropylene homopolymer are examined using fast scanning calorimetry (FSC) and wide-angle X-ray scattering (WAXD). During crystalline nucleation below the glass transition temperature as described by Tammann's two-stage nucleation approach, an increased crystallization rate is observed, regardless of whether the mesophase structures formed in the low-temperature region or α-crystals formed in the high-temperature region. No increase in isothermal crystallization rate is detected following self-nucleation just above the melting point. Additionally, the influence of the pre-existing crystals on the subsequent crystallization behavior is investigated by combining crystallization time and temperature profiles, whereby crystallization at high temperatures is followed by slight crystallization at low temperatures, and in reverse order. Surprisingly, it is confirmed that the presence of pre-existing crystals do not affect the subsequent crystallization rate. The crystallization rate of iPP is influenced only by low-temperature pre-annealing that enhances the pre-nucleation.