Diphylleia Grayi-Inspired Intelligent Temperature-Responsive Transparent Nanofiber Membranes.

Nanofiber membranes (NFMs) have become attractive candidates for next-generation flexible transparent materials due to their exceptional flexibility and breathability. However, improving the transmittance of NFMs is a great challenge due to the enormous reflection and incredibly poor transmission generated by the nanofiber-air interface. In this research, we report a general strategy for the preparation of flexible temperature-responsive transparent (TRT) membranes, which achieves a rapid transformation of NFMs from opaque to highly transparent under a narrow temperature window. In this process, the phase change material eicosane is coated on the surface of the polyurethane nanofibers by electrospray technology. When the temperature rises to 37 °C, eicosane rapidly completes the phase transition and establishes the light transmission path between the nanofibers, preventing light loss from reflection at the nanofiber-air interface. The resulting TRT membrane exhibits high transmittance (> 90%), and fast response (5 s). This study achieves the first TRT transition of NFMs, offering a general strategy for building highly transparent nanofiber materials, shaping the future of next-generation intelligent temperature monitoring, anti-counterfeiting measures, and other high-performance devices.

Uni-directional release of ibuprofen from an asymmetric fibrous membrane enables effective peritendinous anti-adhesion.

Drug-loaded porous membranes have been deemed to be effective physicochemical barriers to separate postoperative adhesion-prone tissues in tendon healing. However, cell viability and subsequent tissue regeneration might be severely interfered with the unrestricted release and the locally excessive concentration of anti-inflammatory drugs. Herein, we report a double-layered membrane with sustained and uni-directional drug delivery features to prevent peritendinous adhesion without hampering the healing outcome. A vortex-assisted electrospinning system in combination with ibuprofen (IBU)-in-water emulsion was utilized to fabricate IBU-loaded poly-ʟ-lactic-acid (PLLA) fiber bundle membrane (PFB-IBU) as the anti-adhesion layer. The resultant highly porous structure, oleophilic and hydrophobic nature of PLLA fibers enabled in situ loading of IBU with a concentration gradient across the membrane thickness. Aligned collagen nanofibers were further deposited at the low IBU concentration side of the membrane for regulating cell growth and achieving uni-directional release of IBU. Drug release kinetics showed that the release amount of IBU from the high concentration side reached 79.32% at 14 d, while it was only 0.35% at the collagen side. Therefore, fibroblast proliferation at the high concentration side was successfully inhibited without affecting the oriented growth of tendon-derived stem cells at the other side. In vivo evaluation of the rat Achilles adhesion model confirmed the successful peritendinous anti-adhesion of our double-layered membrane, in that the macrophage recruitment, the inflammatory factor secretion and the deposition of pathological adhesion markers such as α-SMA and COL-III were all inhibited, which greatly improved the peritendinous fibrosis and restored the motor function of tendon.

Hygroscopic and cool boron nitride Nanosheets/Regenerated flax fiber material microstructure Dual-Cooling composite fabric.

Developing cooling textiles with unidirectional water transport performances and high thermal conductivities is essential for personal thermal and wet comfort in human activities. We report a green, degradable, hygroscopic cooling material and dual-cooling composite fabric (d-CCF). A boron nitride nanosheet/regenerated flax fiber (BNNS/RFF) material with a high thermal conductivity was prepared by dissolving recovered flax fibers with a green, efficient 1-butyl-3-methylimidazole chloride/dimethyl sulfoxide system and adding BNNSs. The 60- wt% BNNS/RFF materials had excellent thermal conductivity and hydrophilicity, the breaking strength reached 120 MPa, and the elongation was 15.8 %. The d-CCF consisted of cool polyester (CPET) yarn (inner layer), CPET/bamboo composite yarn (middle layer), bamboo yarn, and 60- wt% BNNS/RFF (outer layer) with unobstructed heat dissipation and evaporation cooling for effective moisture and thermal management. This d-CCF had distinct advantages, including a high one-way water transport index (468 %), an extremely high evaporation rate (0.3818 g h-1), inner layer maximum heat flux (0.191 W cm-2), and outer layer maximum heat flux (0.249 W cm-2), providing a cooling sensation upon contact. Compared to cotton fabrics, the d-CCF could keep the skin cooler by 2.5 °C. This work provides a strategy to fabricate environmentally friendly BNNS/RFF materials and a facile pathway for cooling textile development for human health management.

Antibacterial Polylactic-co-glycolic Acid Braided Threads Using Plasma and Coating Modifications for Acupoint Catgut Embedding Therapy Applications.

Polylactic-co-glycolic acid (PLGA) thread is frequently used for acupoint catgut embedding therapy (ACET), but the poor hydrophilicity and biocompatibility largely limited its wider applications. The aim of this study is to functionalize the PLGA braided thread and improve its cell adhesion property. The PLGA strands are first processed into threads on a circular braiding machine, and then, antibacterial treatment was introduced with and without oxygen plasma treatments. Afterward, functional characterizations such as antibacterial activity (Staphylococcus aureus and Escherichia coli), cytotoxicity, cell attachment and cell morphology, histological observation, and biodegradation experiments of threads were measured. Moreover, tensile properties and flexibility of the threads were determined to evaluate their mechanical properties. The modified threads showed rougher surfaces than those of the unmodified ones from SEM observations, and the weights and fiber diameters of the threads increased correspondingly, together with the improved surface hydrophilicity. All coated sutures showed durable antimicrobial function and slow drug releasing features for more than 5 days and good cell viability (more than 75%), according to the standard of ISO 10993-5:2009. Besides, cell attachment, tissue growth, and collagen regeneration of plasma-treated samples were greatly improved compared to those of without the plasma treatment. The threads presented slow degradation behavior after the antibacterial treatment. The threads with only plasma-treated revealed a promising prospect for clinical applications.

Prevention of intestinal adhesion and regeneration of abdominal wall tissue with meshes containing an electrostatically spun acellular dermal matrix (ADM)/silk fibroin (SF) fiber composite polypropylene mesh.

The repair of abdominal wall defects often requires the use of polypropylene (PP) as the main material. After a PP mesh is implanted in the body, contact with the intestine can cause adhesions between the intestine and the mesh, leading to serious complications such as intestinal fistula. In this study, we used electrostatic spinning technology to coat one side of PP meshes with an electrostatically spun isolating layer of acellular dermal matrix (ADM)/silk fibroin (SF) hybrid material. These meshes were used to repair abdominal wall defects in model rats and were compared with polycaprolactone (PCL) composite polypropylene meshes and PP meshes. The results showed that the adhesion score and area of ADM/SF-PP meshes were smaller than those of PCL-PP and PP meshes. Immunohistochemical assessment revealed that the ADM/SF meshes could effectively reduce the inflammatory response at the contact surface between the meshes and abdominal organs. The tissues regenerated on the abdominal side were rich in new blood vessels. Furthermore, the ADM/SF meshes could effectively reduce the expression levels of the inflammation-related factors IL-6 and TNF-α. The expression levels of tissue regeneration-related factors, such as VEGF and PAX-7, were also higher after ADM/SF-PP mesh-mediated repair than after PCL-PP mesh and PP mesh repair. Thus, ADM/SF-PP meshes can effectively reduce the inflammatory response at the contact surface between the meshes and abdominal organs and quickly promote regeneration of abdominal surface tissue to prevent and reduce abdominal adhesion and support restoration of the abdominal wall.

Preparation and biocompatibility evaluation of polypropylene mesh coated with electrospinning membrane for pelvic defects repair.

Composite mesh with different materials composition could compensate for the drawbacks brought by single component mesh. Coating a membrane layer on the surface of macroporous mesh is a common method for preparing composite medical mesh. Electrospinning and dipping methods were introduced to form the two kinds of membrane-coated PP meshes (electro-mesh and dip-mesh); several properties were measured based on subcutaneous implantation model in rat. The results revealed that continuous tissue ingrowth could be observed for electro-mesh only with evidences of strength increase (electro-mesh: 0 week - 13.1 ±â€¯0.88 N, 2 week - 16.87 ±â€¯1.39 N, 4 week - 22.04 ±â€¯2.05 N) and thickness increase (electro-mesh: 0 week - 0.437 ±â€¯0.023 mm, 2 week - 0.488 ±â€¯0.025 mm, 4 week - 0.576 ±â€¯0.028 mm). However, no tissues were observed for dip-mesh in the first 2 weeks, both on macroscopic level and microscopic level, proved by strength data (dip-mesh: 0 week - 13.36 ±â€¯1.06 N, 2 week - 13.4 ±â€¯1.33 N, 4 week - 18.61 ±â€¯1.89 N) and thickness data (dip-mesh: 0 week - 0.439 ±â€¯0.018 mm, 2 week - 0.439 ±â€¯0.019 mm, 4 week - 0.502 ±â€¯0.032 mm). Electro-mesh had larger surface area decrease (10.74 ±â€¯1.22%) than that of dip-mesh (2.78 ±â€¯0.52%). The adhesion level of electro-mesh (medium adhesion) was also higher than that of dip-mesh (mild adhesion). Even if showing differences in several properties, both meshes were similar under histological observation, with the ability to support fresh tissues ingrowth. Considering operation environment, electro-mesh seems more suitable than dip-mesh with a rapid tissue growing, medium adhesion rate for repairing pelvic floor defects.