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The clinical translation of therapeutic peptides is generally challenged by multiple issues involving absorption, distribution, metabolism and excretion. In this study, a macrophage membrane-coated poly(lactic-co-glycolic acid) (PLGA) nanodelivery system was developed to enhance the bioavailability of the somatostatin (SST) peptide, which faces the hurdles of short half-life and potential side effects in the treatment of chronic pancreatitis. Using a facile nanoprecipitation strategy, SST was loaded in the nanoparticles with an encapsulation efficiency (EE) and a loading efficiency (LE) of 73.68 ± 3.56% and 1.47 ± 0.07%, respectively. The final formulation of SST-loaded nanoparticles with the camouflage of macrophage membrane (MP-SST) showed a mean diameter of 151 ± 4 nm and an average zeta potential of −29.6 ± 0.3 mV, which were stable long term during storage. With an above 90% cell viability, a hemolysis level of about 2% (<5%) and a preference for being ingested by activated endothelial cells compared to macrophages, the membrane–polymer hybrid nanoparticle showed biocompatibility and targeting capability in vitro. After being intravenously administered to mice with chronic pancreatitis, the MP-SST increased the content of SST in the serum (123.6 ± 13.6 pg/mL) and pancreas (1144.9 ± 206.2 pg/g) compared to the treatment of (Dulbecco's phosphate-buffered saline) DPBS (61.7 ± 6.0 pg/mL in serum and 740.2 ± 172.4 pg/g in the pancreas). The recovery of SST by MP-SST downregulated the expressions of chronic pancreatitis-related factors and alleviated the histologic severity of the pancreas to the greatest extent compared to other treatment groups. This augmentation of SST therapeutic effects demonstrated the superiority of integrating the synthetic polymer with biological membranes in the design of nanoplatforms for advanced and smart peptide delivery. Other peptides like SST can also be delivered via the membrane–polymer hybrid nanosystem for the treatment of diseases, broadening and promoting the potential clinical applications of peptides as therapeutics. [ABSTRACT FROM AUTHOR]

In this study, ultrahigh-molecular-weight polyethylene (UHMWPE) fibres, modified by acetic acid, sulfuric acid and water at a ratio of 20:25:2 for different time periods and modified UHMWPE/EP composites were prepared. The micromorphology, chemical composition, contact angle, H sample extraction, tensile properties and bending performance of the composite material of the UHMWPE fibres before and after modification were tested and analysed. The results show that, after the UHMWPE fibres were treated with the modified liquid, the surface roughness of the fibre increased, the contact angle decreased, and the surface chemical composition and species significantly changed; the mechanical properties of the composites are best when the fibres were treated for 9 min. For the same fibre content, the specific strength, specific modulus and bending load of UHMWPE composites treated for 9 min were increased by 16.7%, 82.9% and 55.3%, respectively, compared with untreated samples. [ABSTRACT FROM AUTHOR]

This work presents a study of liquid oxidation modification effects on the tensile properties of UHMWPE fibers and UHMWPE fiber/epoxy composites. Three types of basic knitted structural composites were produced with 4, 6, and 8 layers. The shop-vacuum-assisted resin transfer molding (VARTM) process was used to laminate the composite. The tensile properties of the composite laminates were evaluated using a universal strength testing machine, and the tensile damage of the materials was analyzed. The results show that for the same number of layers of laminates, the tensile strength of the weft jersey structure was the highest, followed by those of the rib and cardigan structures. The tensile strength increased with the number of layers and increased with a nonlinear positive correlation. After modification, the stretching process did not result in yarn being pulled from the resin. The adhesion to the fabric and the resin increased, and the shear strength of the composite increased between the layers. [ABSTRACT FROM AUTHOR]