Sodium alginate/feather keratin-g-allyloxy polyethylene glycol composite phase change fiber

Photo-thermal effects initiate multi-level energy conversion in "solid-solid" phase-changing fibers

The current textiles primarily employ passive heat barriers to minimize heat loss and achieve effective thermal insulation for human beings. Accordingly, intelligent fibers with energy storage and temperature control capabilities have garnered significant attention due to their potential to revolutionize textile technology. The study integrates the photo-thermal effect and phase change energy storage materials onto a fiber, thereby fabricating a fully intelligent energy storage fiber. This innovation enables the multi-level conversion of sunlight: "Optical energy - Thermal energy - Phase transition energy - Thermal energy". The intelligent fiber efficiently converts solar energy into heat energy through the photo-thermal coupling of CuNPs, subsequently inducing a spatial conformational change in the solid-solid phase change material within the fiber for effective heat storage. The hybrid fiber possesses enhanced mechanical properties but also exhibits a significantly high phase transition enthalpy value of 49.75 J g-1 and a phase transition temperature suitable for human body temperature (20.19-30.21 °C), especially the fiber is more durable. The photo-thermal conversion test vividly demonstrates the systematic transformation of four distinct forms of energy within the composite fiber. This approach holds significant potential for advancing the field of smart fiber technology.

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.

Wound Microenvironment Self-Adjusting Hydrogels with Thermo-Sensitivity for Promoting Diabetic Wound Healing

The hard-healing chronic wounds of diabetics are still one of the most intractable problems in clinical skin injury repair. Wound microenvironments directly affect wound healing speed, but conventional dressings exhibit limited efficacy in regulating the wound microenvironment and facilitating healing. To address this serious issue, we designed a thermo-sensitive drug-controlled hydrogel with wound self-adjusting effects, consisting of a sodium alginate (SA), Antheraeapernyi silk gland protein (ASGP) and poly(N-isopropylacrylamide) (PNIPAM) for a self-adjusting microenvironment, resulting in an intelligent releasing drug which promotes skin regeneration. PNIPAM has a benign temperature-sensitive effect. The contraction, drugs and water molecules expulsion of hydrogel were generated upon surpassing lower critical solution temperatures, which made the hydrogel system have smart drug release properties. The addition of ASGP further improves the biocompatibility and endows the thermo-sensitive drug-controlled hydrogel with adhesion. Additionally, in vitro assays demonstrate that the thermo-sensitive drug-controlled hydrogels have good biocompatibility, including the ability to promote the adhesion and proliferation of human skin fibroblast cells. This work proposes an approach for smart drug-controlled hydrogels with a thermo response to promote wound healing by self-adjusting the wound microenvironment.

Investigation on Centrifugally Spun Fibrous PCL/3-Methyl Mannoside Mats for Wound Healing Application

Fibrous structures, in general, have splendid advantages in different forms of micro- and nanomembranes in various fields, including tissue engineering, filtration, clothing, energy storage, etc. In the present work, we develop a fibrous mat by blending the bioactive extract of Cassia auriculata (CA) with polycaprolactone (PCL) using the centrifugal spinning (c-spinning) technique for tissue-engineered implantable material and wound dressing applications. The fibrous mats were developed at a centrifugal speed of 3500 rpm. The PCL concentration for centrifugal spinning with CA extract was optimized at 15% w/v of PCL to achieve better fiber formation. Increasing the extract concentration by more than 2% resulted in crimping of fibers with irregular morphology. The development of fibrous mats using a dual solvent combination resulted in fine pores on the fiber structure. Scanning electron microscope (SEM) images showed that the surface morphology of the fibers in the produced fiber mats (PCL and PCL-CA) was highly porous. Gas chromatography-mass spectrometry (GC-MS) analysis revealed that the CA extract contained 3-methyl mannoside as the predominant component. The in vitro cell line studies using NIH3T3 fibroblasts demonstrated that the CA-PCL nanofiber mat was highly biocompatible, supporting cell proliferation. Hence, we conclude that the c-spun, CA-incorporating nanofiber mat can be employed as a tissue-engineered construct for wound healing applications.

An Eco-Friendly Antheraea Pernyi Silk Gland Protein/Sodium Alginate Multiple Network Hydrogel as Potential Drug Release Systems

To improve the versatility of the sodium alginate-loaded bio-hydrogels, Antheraea pernyi silk gland protein/sodium alginate drug-loaded hydrogels were prepared by using an eco-friendly multiple network cross-link technology. Fourier transform infrared (FT-IR) spectroscopy and UV-Vis spectrophotometer were used separately to evaluate the chemical structure and drug release behavior of drug-loaded hydrogels. The antibacterial drug carrier gels were evaluated by using inhibition zone test against the S. aureus and E. coli. The CCK-8 assay was used to assess the biocompatibility of drug loaded hydrogels. The FT-IR results showed that there was a strong interaction within the drug loaded hydrogels, and the ASGP was beneficial to enhance the interaction within the drug loaded hydrogels. UV-Vis spectrophotometer results indicated the cumulative release reached 80% within 400 min. Antibacterial bio-hydrogels had a good antibacterial property, especially the antibacterial bio-hydrogels with bacitracin exhibits superior to other antibacterial agents. The drug-loaded bio-hydrogels exhibited the adhesion and proliferation of RSC96 cells and perfected biocompatibility. This provides a new idea for further research and development of tissue-friendly drug-loaded biomaterials.

Preparation of PEG-modified wool keratin/sodium alginate porous scaffolds with elasticity recovery and good biocompatibility

To improve mechanical properties of keratin (KR) porous scaffolds, we prepared a PEGylated keratin through thiol-ene click reaction. Several porous scaffolds were prepared by blending PEGylated keratin with sodium alginate (SA). The surface morphology, mechanical properties, and porosity of scaffolds were detailed studied at different KR/SA proportions. The results showed the content of SA had an effect on pore formation and mechanical properties. When the mass ratio of KR to SA was 2:1, the stress of yield point of the keratin porous scaffold reached 1.24 MPa, and also showed good deformation recovery ability. The PEGylated keratin porous scaffold had a high porosity and great cytocompatibility. Its' porosity is up to 81.7% and the cell viability is about 117.78%. This allows it to absorb the simulated plasma quickly (9.20 ± 0.37 g/g). In addition, the structural stability and acid-base stability of the keratin porous scaffold were also improved after PEGylation. Overall, the PEGylated keratin porous scaffold will be promising in tissue materials due to its great physical, chemical, and biological properties.

A sodium alginate/feather keratin composite fiber with skin-core structure as the carrier for sustained drug release

To alleviate the serious gastrointestinal side reaction of indomethacin (IDM), sodium alginate/feather keratin (SA/FK) fiber with skin-core structure was prepared via wet spinning as the carrier for sustained release of IDM. Fourier translation infrared (FT-IR) spectroscopy was adopted to investigate the reaction mechanism among SA, FK and IDM, and Ultraviolet-visible (UV-Vis) spectroscopy was used to systematically evaluate the sustained release capacity of SA/FK fiber in three simulated fluids. Scanning electron microscope (SEM) was employed to observe the apparent morphology of SA/FK fiber. The results indicate that, release amount of IDM exhibits an increase trend along with time; the release amount of IDM reaches 80% after 12 h in colon fluid and small intestinal fluid, and is less than 20% in digestive fluid. Simultaneously, FK can effectively control the release of IDM, and with the increase of FK content, IDM release time of the carrier fiber extends.

Cellulosic scaffolds doped with boron nitride nanosheets for shape-stabilized phase change composites with enhanced thermal conductivity

Phase change materials (PCMs), widely used in thermal management filed, can store or release thermal energy during phase-changing processes, but the inherent low thermal conductivity and leakage problem restrict their practical applications. Herein, boron nitride nanosheets (BNNSs) doped cellulosic scaffolds (CS) were used as novel support materials to construct shape-stabilized PCM with enhanced thermal conductivity. The composite PCM exhibits excellent shape stability against pressure, tension and bending (90°) even at high loading of the solid-liquid PCM polyethylene glycol (PEG) (95.6 wt%). The resulting composite PCMs have enthalpy capacity (ΔH_m/ΔH_c) ranged from 165.3 J g^-1/169.3 J g^-1 to 169.1 J g^-1/176.1 J g^-1 with stable cycling reliability. Moreover, the thermal conductivity of the composite PCM could increase by 42.8% at a low loading of BNNSs (1.9 wt%), without affecting its electrical insulation properties (over 10⁷ Ω cm). The thermally-conductive shape-stabilized PCM composite prepared by this feasible method have great potential in thermal management of electronics.