Construction and mechanism analysis of flame-retardant, energy-storage and transparent bio-based composites based on natural cellulose template.

With the proposal of sustainable development strategy, bio-based energy storage transparent wood (TW) has shown broad application value in green buildings, cold chain transportation, and optoelectronic device fields. However, its application in most fields is limited due to its own flammability. In this study, epoxy resin, triethyl phosphate (TEP) and polyethylene glycol (PEG) were introduced into delignified balsa wood template by vacuum pressure impregnation, and bio-based TW/PEG/TEP integrating flame retardant, high strength and phase-change energy-storage performance was prepared. TW/PEG composites have no leakage during phase change process and their transparency is up to 95 %. Compared with TW/PEG, the shielding effect of char layer and the inhibition effect in condensed and gas phase significantly decrease the total heat release of TW/PEG/TEP. TW/PEG/TEP biocomposites still maintained a high enthalpy of phase change and a low peak melting temperature, which was conducive to its application around the area of low temperature phase change energy storage. In addition, the tensile strength of TW/PEG/TEP was nearly 4 times higher than that of DW, and its toughness was obviously enhanced. TW/PEG/TEP biocomposites conformed to the current concept of energy-saving and green development. It has the potential to replace traditional petrochemical-based materials and shows excellent application prospects in emerging fields.

Porcine urinary bladder matrix-polypropylene mesh: a novel scaffold material reduces immunorejection in rat pelvic surgery.

INTRODUCTION AND HYPOTHESIS: The present study set out to modify polypropylene vaginal surgical material using porcine urinary bladder matrix (UBM) in order to improve biocompatibility. The aim was to develop a compound scaffold that induced less vaginal erosion and to evaluate host immunoreactivity to this material in vivo. METHODS: Forty-eight Sprague-Dawley rats were randomly divided into four equal groups. One group underwent a sham operation, and the other groups underwent vaginal implantation with different materials: UBM (U); UBM + polypropylene (UP); or polypropylene (P). The host tissue response was determined by macro-observation, and by histological and immunohistochemical methods at 7, 14, 21, or 28 days after surgery. RESULTS: The inflammation reaction was strongest throughout the entire observation time in Group P, but was weaker and had a tendency to decrease with time in Groups U and UP. The presence of the UBM material in the compound scaffold allowed the polypropylene to fuse with newly proliferating surrounding tissue and resulted in less rejection of the material by the host, as indicated by the reduced appearance of CD4-, and CD8-positive cells. CONCLUSIONS: Porcine UBM allowed mechanical isolation of polypropylene, and also reduced the immune reaction to polypropylene. This study suggests that the UBM + polypropylene compound scaffold may be a promising material for clinical use in pelvic reconstruction surgery.

Preparation of a small intestinal submucosa modified polypropylene hybrid mesh via a mussel-inspired polydopamine coating for pelvic reconstruction.

Pelvic organ prolapse (POP) is a serious health issue that affects many adult women. Surgical treatments for POP patients comprise a common strategy in which scaffold materials are used to reconstruct the prolapsed pelvic. However, the existing materials for pelvic reconstruction cannot meet clinical requirements in terms of biocompatibility, mechanics and immunological rejection. To address these concerns, polypropylene (PP) mesh was selected because of its strong mechanical properties. Small intestinal submucosa (SIS) was used to modify the PP mesh via a mussel-inspired polydopamine coating to enhance its biocompatibility. The scanning electron microscopy (SEM) and atomic force microscopy (AFM) results demonstrated that SIS was successfully conjugated on the surface of the PP mesh. Moreover, the cytotoxicity results indicated that the PP mesh and SIS-modified PP mesh were safe to use. Furthermore, in vivo tests demonstrated that the fibroplasia around the implanted site in the SIS-modified PP mesh group was significantly less than the fibroplasia around the PP mesh group. In addition, the immunohistochemistry staining results indicated that the expression of pro-inflammatory macrophages (M1) was substantially lower and that the expression of pro-healing macrophages (M2) was higher in the SIS-modified PP mesh group. Furthermore, ELISA detection indicated that the expression of IL-1ß and IL-6 in the SIS-modified PP mesh group was reduced compared with the PP mesh group. These findings suggest that a SIS-modified polypropylene hybrid mesh via a mussel-inspired polydopamine coating is a promising approach in pelvic reconstruction.