Transition Metal Ions Enable the Transition from Electrospun Prolamin Protein Fibers to Nitrogen-Doped Freestanding Carbon Films for Flexible Supercapacitors

Flexible carbon ultrafine fibers are highly desirable in energy storage and conversion devices. Our previous finding showed that electrospun hordein/zein fibers stabilized by Ca²⁺ were successfully transferred into nitrogen-doped carbon ultrafine fibers for supercapacitors. However, their relatively brittle nature needed to be improved. Inspired by this stabilizing effect of Ca²⁺, in this work, four transition metal divalent cations were used to assist the formation of flexible hordein/zein-derived carbon ultrafine fibers. Without alteration of the electrospinnability, adequate amounts of zinc acetate and cobalt acetate supported the fibrous structure during pyrolysis. This resulted in flexible freestanding carbon films consisting of well-defined fibers with nitrogen-doped graphitic layers and hierarchical pores. These carbon films were easily cut into small square pieces and directly applied as working electrode in the three-electrode testing system without the need for polymer binders or conducting agents. Notably, the hz-Zn0.3-p electrode, synthesized with 0.3 mol/L Zn²⁺ and post-acid treatment, exhibited a specific capacitance of 393 F/g (at 1 A/g), a large rate capability (72.3% remained at 20 A/g), and a capacitance retention of ∼98% after 2000 charging–discharging cycles at 10 A/g. These superior electrochemical properties were attributed to the synergistic effects of the well-developed graphitic layers induced by Zn²⁺, the nitrogen-decorated carbon structure, and the interconnected channels generated by HCl treatment. This research advances potential applications for prolamin proteins as nitrogen-containing raw materials in developing carbon structures for high-performance supercapacitors

Chitin Nanofibrils to Stabilize Long-Life Pickering Foams and Their Application for Lightweight Porous Materials

The demand of sustainable development is challenging researchers to convert renewable resourced biomass into functional materials via environmentally friendly and sustainable pathways. This work introduces a long-life Pickering foam stabilized by chitin nanofibers (CNFs) as colloidal rod-like particles, and a facile method for fabricating lightweight porous solid foams that recycles biomass materials derived from seafood waste. These foams were formed by combining nonionic surfactant Tween 20 (T20) and CNFs, with the CNFs being irreversibly adsorbed at the air–water interface to provide Pickering stabilization. At a concentration of 7.5 mg/mL, the foams could be stable for over 1 week without any apparent drainage. The rheological data indicated the formation of gel networks by self-aggregated CNFs at the air–water interface, which provided long-term stabilization by preventing foam coalescence and disproportionation. This long-term stability of CNF-T20 wet foam has permitted the fabrication of solid porous matrix by removal of the water through simple air-drying. The air-dried chitin foams were ultralight weight porous materials with porosity of 99.4% and a density of 8.84 kg/m³. In addition, they exhibited significantly improved mechanical performance (Young’s modulus of ∼290.2 kPa) compared to porous chitin materials of comparable densities prepared by a traditional freeze-drying method. Therefore, this research has provided a convenient pathway for scalable processing of macroporous material from renewable biomass for potential applications in packaging, pollutant treatment, catalysis, tissue engineering and other related fields

Biodegradable Pea Protein Fibril Hydrogel-Based Quasi-Solid-State Zn-Ion Battery

Zinc-ion batteries show great potential as the next-generation power source due to their nontoxic, low-cost, and safe properties. However, issues with zinc anodes, such as dendrite growth and parasitic hydrogen evolution reactions (HERs), must be addressed to commercialize them. Solutions, such as quasi-solid-state electrolytes made from synthetic polymer hydrogels, have been proposed to improve battery flexibility and energy density. However, most polymers used are nonbiodegradable, posing a challenge to sustainability. In this study, hydrogels made from biodegradable poly(vinyl alcohol) and protein nanofibrils from pea protein, a renewable plant-based source, are used as an electrolyte in aqueous zinc-ion batteries. Results show that the flexible and biodegradable hydrogel can enhance the zinc anode stability and effectively restrict HER. This phenomenon is because of the hydrogen-bond network between nanofibril functional groups and water molecules. In addition, the interaction between functional groups on nanofibrils and Zn2+ constructs ion channels for the even migration of Zn2+, avoiding dendrite growth. The Zn||Zn symmetric cell using the hydrogel electrolyte exhibits a long lifespan of over 3000 h and improved capacity retention in the Zn||AC-I2 hybrid ion batteries by suppressing cathode material dissolution. This study suggests the potential of biodegradable hydrogels as a sustainable and effective solution for biodegradable soft powering sources

Injectable Self-Healing Hydrogel with Antimicrobial and Antifouling Properties

Microbial adhesion, biofilm formation and associated microbial infection are common challenges faced by implanted biomaterials (e.g., hydrogels) in bioengineering applications. In this work, an injectable self-healing hydrogel with antimicrobial and antifouling properties was prepared through self-assembly of an ABA triblock copolymer employing catechol functionalized polyethylene glycol (PEG) as A block and poly­{[2-(methacryloyloxy)-ethyl] trimethylammonium iodide}­(PMETA) as B block. This hydrogel exhibits excellent thermosensitivity, and can effectively inhibit the growth of <i>E. coli</i> (>99.8% killing efficiency) and prevent cell attachment. It can also heal autonomously from repeated damage, through mussel-inspired catechol-mediated hydrogen bonding and aromatic interactions, exhibiting great potential in bioengineering applications

DataSheet_1_Photodegradation of biobased polymer blends in seawater: A major source of microplastics in the marine environment.docx

IntroductionBiobased polymer blends have been recommended as an eco-friendly solution to abate plastic pollution in the environment. However, the formation of microplastics (MPs) by photodegradation of biobased polymer blends in the marine environment is still not well understood. In this study, we investigated the formation of MPs and the changes in the physicochemical properties of three types of biobased polymer blends after photodegradation in seawater.MethodsThe investigated materials included non-biodegradable polyethylene/ thermoplastic starch blends (PE/TPS) and polypropylene/thermoplastic starch blends (PP/TPS), as well as biodegradable polylactic acid/poly (butylene adipate-co-terephthalate)/thermoplastic starch blends (PLA/PBAT/TPS). The control groups were the corresponding neat polymers, including polyethylene (PE), polypropylene (PP), and polylactic acid (PLA).ResultsThe size distribution of the pristine and aged MPs indicated that the polymer blends were more likely to produce small-sized particles after photodegradation due to their poorer mechanical properties and lower resistance to UV irradiation than the neat polymers. Noticeable surface morphology alterations, including cracks, holes, and pits, were observed for polymer blends after photodegradation, while neat polymers were relatively resistant. After photodegradation, the attenuated total reflection Fourier transformed infrared spectroscopy (ATR-FTIR) spectrum of the polymer blends showed a significant decrease in the characteristic bands of thermoplastic starch (TPS), indicating depletion of their starch fractions. The C1s spectra of the polymer blends demonstrated that the aged MPs contained fewer -OH groups than the pristine MPs, further confirming the photodegradation of TPS. The molecular weight distribution curve of the polymer blends shifted significantly towards low molecular weight, suggesting the occurrence of chain scission during photodegradation. These results indicate that the polymer blends have a higher degree of photodegradation than neat polymers, and thereby generate more small-sized MPs than neat polymers. Photodegradation caused changes in the contact angle and surface charge of MPs derived from biobased polymer blends, which may affect the vector effects of MPs on any coexisting pollutants.DiscussionIn summary, polymer blends may pose a higher risk to the marine environment than neat polymers, and caution should be taken in promoting biobased polymer blends.</p

Table_1_Association between human leukocyte antigen and immunosuppressive treatment outcomes in Chinese patients with aplastic anemia.docx

BackgroundActivated cytotoxic T cells (CTLs) recognize the auto-antigens presented on hematopoietic stem/progenitor cells (HSPCs) through class I human leukocyte antigen (HLA) molecules and play an important role in the immune pathogenesis of aplastic anemia (AA). Previous reports demonstrated that HLA was related to the disease susceptibility and response to immunosuppressive therapy (IST) in AA patients. Recent studies have indicated that specific HLA allele deletions, which helped AA patients to evade CTL-driven autoimmune responses and escape from immune surveillance, may lead to high-risk clonal evolution. Therefore, HLA genotyping has a particular predictive value for the response to IST and the risk of clonal evolution. However, there are limited studies on this topic in the Chinese population.MethodsTo explore the value of HLA genotyping in Chinese patients with AA, 95 AA patients treated with IST were retrospectively investigated.ResultsThe alleles HLA-B*15:18 and HLA-C*04:01 were associated with a superior long-term response to IST (P = 0.025; P = 0.027, respectively), while the allele HLA-B*40:01 indicated an inferior result (P = 0.02). The allele HLA-A*01:01 and HLA-B*54:01 were associated with high-risk clonal evolution (P = 0.032; P = 0.01, respectively), and the former had a higher frequency in very severe AA (VSAA) patients than that in severe AA (SAA) patients (12.7% vs 0%, P = 0.02). The HLA-DQ*03:03 and HLA-DR*09:01 alleles were associated with high-risk clonal evolution and poor long-term survival in patients aged ≥40 years. Such patients may be recommended for early allogeneic hematopoietic stem cell transplantation rather than the routine IST treatment.ConclusionHLA genotype has crucial value in predicting the outcome of IST and long-term survival in AA patients, and thus may assist an individualized treatment strategy.</p