Coaxial nanofibrous aerogel featuring porous network-structured channels for ovarian cancer treatment by sustained release of chitosan oligosaccharide.

Ovarian cancer, the deadliest gynecological malignancy, primarily treated with chemotherapy. However, systemic chemotherapy often leads to severe toxic side effects and chemoresistance. Drug-loaded aerogels have emerged as a promising method for drug delivery, as they can improve drug solubility and bioavailability, control drug release, and reduce drug distribution in non-targeted tissues, thereby minimizing side effects. In this research, chitosan oligosaccharide (COS)-loaded nanofibers composite chitosan (CS) aerogels (COS-NFs/CS) with a porous network structure were created using nanofiber recombination and freeze-drying techniques. The core layer of the aerogel has a COS loading rate of 60 %, enabling the COS-NFs/CS aerogel to significantly inhibit the migration and proliferation of ovarian cancer cells (resulting in a decrease in the survival rate of ovarian cancer cells to 33.70 % after 48 h). The coaxial fiber's unique shell-core structure and the aerogel's porous network structure enable the COS-NFs/CS aerogels to release COS steadily and slowly over 30 days, effectively reducing the initial burst release of COS. Additionally, the COS-NFs/CS aerogels exhibit good biocompatibility, degradability (only retaining 18.52 % of their weight after 6 weeks of implantation), and promote angiogenesis, thus promoting wound healing post-oophorectomy. In conclusion, COS-NFs/CS aerogels show great potential for application in the treatment of ovarian cancer.

Self-Adapting Biomass Hydrogel Embodied with miRNA Immunoregulation and Long-Term Bacterial Eradiation for Synergistic Chronic Wound Therapy.

Chronic wound rescue is critical for diabetic patients but is challenging to achieve with a specific and long-term strategy. The prolonged bacterial inflammation is particularly prevalent in hyperglycemia-induced wounds, usually leading to severe tissue damage. Such a trend could further suffer from an environmental suitability provided by macrophages for persisting Staphylococcus aureus (S. aureus) and even deteriorate by their mutual reinforcement. However, the strategy of both suppressing bacteria growth and immunoreprogramming the inflammatory type of macrophages to break their vicious harm to wound healing is still lacking. Here, a self-adapting biomass carboxymethyl chitosan (CMC) hydrogel comprising immunomodulatory nanoparticles is reported to achieve Gram-negative/Gram-positive bacteria elimination and anti-inflammatory cytokines induction to ameliorate the cutaneous microenvironment. Mechanistically, antibacterial peptides and CMCs synergistically result in a long-term inhibition against methicillin-resistant S. aureus (MRSA) over a period of 7 days, and miR-301a reprograms the M2 macrophage via the PTEN/PI3Kγ/mTOR signaling pathway, consequently mitigating inflammation and promoting angiogenesis for diabetic wound healing in rats. In this vein, immunoregulatory hydrogel is a promising all-biomass dressing ensuring biocompatibility, providing a perspective to regenerate cutaneous damaged tissue, and repairing chronic wounds on skin.

Biomass waste-assisted micro(nano)plastics capture, utilization, and storage for sustainable water remediation.

Micro(nano)plastics (MNPs) have become a significant environmental concern due to their widespread presence in the biosphere and potential harm to ecosystems and human health. Here, we propose for the first time a MNPs capture, utilization, and storage (PCUS) concept to achieve MNPs remediation from water while meeting economically productive upcycling and environmentally sustainable plastic waste management. A highly efficient capturing material derived from surface-modified woody biomass waste (M-Basswood) is developed to remove a broad spectrum of multidimensional and compositional MNPs from water. The M-Basswood delivered a high and stable capture efficiency of >99.1% at different pH or salinity levels. This exceptional capture performance is driven by multiscale interactions between M-Basswood and MNPs, involving physical trapping, strong electrostatic attractions, and triggered MNPs cluster-like aggregation sedimentation. Additionally, the in vivo biodistribution of MNPs shows low ingestion and accumulation of MNPs in the mice organs. After MNPs remediation from water, the M-Basswood, together with captured MNPs, is further processed into a high-performance composite board product where MNPs serve as the glue for utilization and storage. Furthermore, the life cycle assessment (LCA) and techno-economic analysis (TEA) results demonstrate the environmental friendliness and economic viability of our proposed full-chain PCUS strategy, promising to drive positive change in plastic pollution and foster a circular economy.

Activating Adsorption Sites of Waste Crayfish Shells via Chemical Decalcification for Efficient Capturing of Nanoplastics.

The property of being stubborn and degradation resistant makes nanoplastic (NP) pollution a long-standing remaining challenge. Here, we apply a designed top-down strategy to leverage the natural hierarchical structure of waste crayfish shells with exposed functional groups for efficient NP capture. The crayfish shell-based organic skeleton with improved flexibility, strength (14.37 to 60.13 MPa), and toughness (24.61 to 278.98 MJ m-3) was prepared by purposefully removing the inorganic components of crayfish shells through a simple two-step acid-alkali treatment. Due to the activated functional groups (e.g., -NH2, -CONH-, and -OH) and ordered architectures with macropores and nanofibers, this porous crayfish shell exhibited effective removal capability of NPs (72.92 mg g-1) by physical interception and hydrogen bond/electrostatic interactions. Moreover, the sustainability and stability of this porous crayfish shell were demonstrated by the maintained high-capture performance after five cycles. Finally, we provided a postprocessing approach that could convert both porous crayfish shell and NPs into a tough flat sheet. Thus, our feasible top-down engineering strategy combined with promising posttreatment is a powerful contender for a recycling approach with broad application scenarios and clear economic advantages for simultaneously addressing both waste biomass and NP pollutants.

Selective cleavage of C ß -O-4 bond for lignin depolymerization via paired-electrolysis in an undivided cell.

The cleavage of C-O bonds is one of the most promising strategies for lignin-to-chemicals conversion, which has attracted considerable attention in recent years. However, current catalytic system capable of selectively breaking C-O bonds in lignin often requires a precious metal catalyst and/or harsh conditions such as high-pressure H2 and elevated temperatures. Herein, we report a novel protocol of paired electrolysis to effectively cleave the Cß-O-4 bond of lignin model compounds and real lignin at room temperature and ambient pressure. For the first time, "cathodic hydrogenolysis of Cß-O-4 linkage" and "anodic C-H/N-H cross-coupling reaction" are paired in an undivided cell, thus the cleavage of C-O bonds and the synthesis of valuable triarylamine derivatives could be simultaneously achieved in an energy-effective manner. This protocol features mild reaction conditions, high atom economy, remarkable yield with excellent chemoselectivity, and feasibility for large-scale synthesis. Mechanistic studies indicate that indirect H* (chemical absorbed hydrogen) reduction instead of direct electron transfer might be the pathway for the cathodic hydrogenolysis of Cß-O-4 linkage.

Nanofiber-induced hierarchically-porous magnesium phosphate bone cements accelerate bone regeneration by inhibiting Notch signaling.

Magnesium phosphate bone cements (MPC) have been recognized as a viable alternative for bone defect repair due to their high mechanical strength and biodegradability. However, their poor porosity and permeability limit osteogenic cell ingrowth and vascularization, which is critical for bone regeneration. In the current study, we constructed a novel hierarchically-porous magnesium phosphate bone cement by incorporating extracellular matrix (ECM)-mimicking electrospun silk fibroin (SF) nanofibers. The SF-embedded MPC (SM) exhibited a heterogeneous and hierarchical structure, which effectively facilitated the rapid infiltration of oxygen and nutrients as well as cell ingrowth. Besides, the SF fibers improved the mechanical properties of MPC and neutralized the highly alkaline environment caused by excess magnesium oxide. Bone marrow stem cells (BMSCs) adhered excellently on SM, as illustrated by formation of more pseudopodia. CCK8 assay showed that SM promoted early proliferation of BMSCs. Our study also verified that SM increased the expression of OPN, RUNX2 and BMP2, suggesting enhanced osteogenic differentiation of BMSCs. We screened for osteogenesis-related pathways, including FAK signaing, Wnt signaling and Notch signaling, and found that SM aided in the process of bone regeneration by suppressing the Notch signaling pathway, proved by the downregulation of NICD1, Hes1 and Hey2. In addition, using a bone defect model of rat calvaria, the study revealed that SM exhibited enhanced osteogenesis, bone ingrowth and vascularization compared with MPC alone. No adverse effect was found after implantation of SM in vivo. Overall, our novel SM exhibited promising prospects for the treatment of critical-sized bone defects.

A Universal Biomacromolecule-Enabled Assembly Strategy for Constructing Multifunctional Aerogels with 90% Inorganic Mass Loading from Inert Nano-Building Blocks.

Inert inorganic nano-building blocks, such as carbon nanotubes (CNTs) and boron nitride (BN) nanosheets, possess excellent physicochemical properties. However, it remains challenging to build aerogels with these inert nanomaterials unless they are chemically modified or compounded with petrochemical polymers, which affects their intrinsic properties and is usually not environmentally friendly. Here, a universal biomacromolecule-enabled assembly strategy is proposed to construct aerogels with 90 wt% ultrahigh inorganic loading. The super-high inorganic content is beneficial for exploiting the inherent properties of inert nanomaterials in multifunctional applications. Taking chitosan-CNTs aerogel as a proof-of-concept demonstration, it delivers sensitive pressure response as a pressure sensor, an ultrahigh sunlight absorption (94.5%) raising temperature under light (from 25 to 71 °C within 1 min) for clean-up of crude oil spills, and superior electromagnetic interference shielding performance of up to 68.9 dB. This strategy paves the way for the multifunctional application of inert nanomaterials by constructing aerogels with ultrahigh inorganic loading.

Dopamine-Modified Chitosan Patterning Hydrogel with Dynamic Information Storage Ability.

The storage of dynamic information in hydrogels has aroused considerable interest regarding the multiple responsiveness of soft matter. Herein, we propose an electrical writing methodology to prepare dopamine (DA)-modified chitosan hydrogels with a dynamic information storage ability. A pH-responsive chitosan hydrogel medium was patterned by cathodic writing to in situ generate OH- in the writing area, at which dopamine underwent an auto-oxidation reaction in the locally alkaline environment to generate a dark color. The patterned information on the hydrogel can be encoded simply by electrical signals. The speed of information retrieval is positively correlated with the charge transfer during the electrical writing process, and the hiding of information is negatively correlated with the environmental stimulus (i.e., dopamine concentration, pH value, etc.). To showcase the versatility of this medium for information storage and the precision of the pattern, a quick response (QR) code is electronically written on dopamine-modified chitosan hydrogel and can be recognized programmably by a standard mobile phone. The results show that electrical regulation is a novel means to program the information storage process of hydrogels, which inspires future research on structural and functional information storage using stimulus-responsive hydrogels.

Janus silk fibroin/polycaprolactone-based scaffold with directionally aligned fibers and porous structure for bone regeneration.

To promote bone repair, it is desirable to develop three-dimensional multifunctional fiber scaffolds. The densely stacked and tightly arranged conventional two-dimensional electrospun fibers hinder cell penetration into the scaffold. Most of the existing three-dimensional structural materials are isotropic and monofunctional. In this research, a Janus nanofibrous scaffold based on silk fibroin/polycaprolactone (SF/PCL) was fabricated. SF-encapsulated SeNPs demonstrated stability and resistance to aggregation. The outside layer (SF/PCL/Se) of the Janus nanofiber scaffold displayed a structured arrangement of fibers, facilitating cell growth guidance and impeding cell invasion. The inside layer (SF/PCL/HA) featured a porous structure fostering cell adhesion. The Janus fiber scaffold containing SeNPs notably suppressed S. aureus and E. coli activities, correlating with SeNPs concentration. In vitro, findings indicated considerable enhancement in alkaline phosphatase (ALP) activity of MC3T3-E1 osteoblasts and upregulation of genes linked to osteogenic differentiation with exposure to the SF/PCL/HA/Se Janus nanofibrous scaffold. Moreover, in vivo, experiments demonstrated successful critical bone defect repair in mouse skulls using the SF/PCL/HA/Se Janus nanofiber scaffold. These findings highlight the potential of the SF/PCL-based Janus nanofibrous scaffold, integrating SeNPs and nHA, as a promising biomaterial in bone tissue engineering.

Programmable Electrical Signals Induce Anisotropic Assembly of Multilayer Chitosan Hydrogels.

Multilayer hydrogels are widely used in biomedical-related fields due to their complex and variable spatial structures. Various strategies have been developed for preparing multilayer hydrogels, among which electrically induced self-assembly provides a simple and effective method for multilayer hydrogel fabrication. By application of an oscillatory electrical signal sequence, multilayer hydrogels with distinct boundaries can be formed according to the provided programmable signals. In this work, we establish an electrical field in microfluidics combined with polarized light microscopy for in situ visualization of anisotropic construction of multilayer chitosan hydrogel. The noninvasive, real-time birefringence images allow us to monitor the orientation within the hydrogel in response to electrical signals. An increased birefringence was observed from the solution-gel side to the electrode surface side, and a brief electrical signal interruption did not affect the anisotropic assembly process. This understanding of the oscillatory electrical signal-induced hydrogel anisotropy assembly allows us to fabricate chitosan hydrogels with a complex and spatially varying structure.

Cellulose nanofibers embedded chitosan/tannin hydrogel with high antibacterial activity and hemostatic ability for drug-resistant bacterial infected wound healing.

Millions of patients annually suffer life-threatening illnesses caused by bacterial infections of skin wounds. However, the treatment of wounds infected with bacteria is a thorny issue in clinical medicine, especially with drug-resistant bacteria infections. Therefore, there is an increasing interest in developing wound dressings that can efficiently fight against drug-resistant bacterial infections and promote wound healing. In this work, an anti-drug-resistant bacterial chitosan/cellulose nanofiber/tannic acid (CS/CNF/TA) hydrogel with excellent wound management ability was developed by electrospinning and fiber breakage-recombination. The hydrogel exhibited an outstanding antibacterial property exceeding 99.9 %, even for drug-resistant bacteria. This hydrogel could adhere to the tissue surface due to its abundant catechol groups, which avoided the shedding of hydrogel during the movement. Besides, it exhibited extraordinary hemostatic ability during the bleeding phase of the wound and then regulated the wound microenvironment by absorbing water and moisturizing. Moreover, the CS/CNF/TA also promoted the regrowth of vessels and follicles, accelerating the healing of infected wound tissue, with a healing rate exceeding 95 % within a 14-day timeframe. Therefore, the CS/CNF/TA hydrogel opens a new approach for the healing of drug-resistant bacterial infected wounds.

Utility of Immunohistochemistry in the Diagnosis of Pleuropulmonary and Mediastinal Cancers: A Review and Update.

CONTEXT.­: Immunohistochemistry has become a valuable ancillary tool for the accurate classification of pleuropulmonary and mediastinal neoplasms necessary for therapeutic decisions and predicting prognostic outcome. Diagnostic accuracy has significantly improved because of the continuous discoveries of tumor-associated biomarkers and the development of effective immunohistochemical panels. OBJECTIVE.­: To increase the accuracy of diagnosis and classify pleuropulmonary neoplasms through immunohistochemistry. DATA SOURCES.­: Literature review and the author's research data and personal practice experience. CONCLUSIONS.­: This review article highlights that appropriately selecting immunohistochemical panels enables pathologists to effectively diagnose most primary pleuropulmonary neoplasms and differentiate primary lung tumors from a variety of metastatic tumors to the lung. Knowing the utilities and pitfalls of each tumor-associated biomarker is essential to avoid potential diagnostic errors.

Long-term antibacterial activity by synergistic release of biosafe lysozyme and chitosan from LBL-structured nanofibers.

Biosafe antibacterial agents are urgently demanded in treating infection especially chronic infection. However, efficient and controlled release of those agents remains great challenging. Two nature-derived agents, lysozyme (LY) and chitosan (CS), are selected to establish a facile method for long-term bacterial inhibition. We incorporated LY into the nanofibrous mats, then deposited CS and polydopamine (PDA) on the surface by layer-by-layer (LBL) self-assembly. In this vein, LY is gradually released with the degradation of nanofibers, and CS is rapidly disassociated from the nanofibrous mats to synergistically result in a potent inhibition against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) over a period of 14 days. Besides long-term antibacterial capacity, LBL-structured mats could readily achieve a strong tensile stress of 6.7 MPa with an increase percentage of up to 103%. The enhanced proliferation of L929 cells arrives at 94% with help of CS and PDA on the surface of nanofibers. In this vein, our nanofiber has a variety of advantages including biocompatibility, strong long-term antibacterial effect, and skin adaptability, revealing the significant potential to be used as highly safe biomaterial for wound dressings.

Yeast biomass ornamented macro-hierarchical chitin nanofiber aerogel for enhanced adsorption of cadmium(II) ions.

There is an urgent need to develop sustainable, renewable, and environment-friendly adsorbents to rectify heavy metals from water. In the current study, a green hybrid aerogel was prepared by immobilizing yeast on chitin nanofibers in the presence of a chitosan interacting substrate. A cryo-freezing technique was employed to construct a 3D honeycomb architecture comprising the hybrid aerogel with excellent reversible compressibility and abundant water transportation pathways for the accelerated diffusion of Cadmium(II) (Cd(II)) solution. This 3D hybrid aerogel structure offered copious binding sites to accelerate the Cd(II) adsorption. Moreover, the addition of yeast biomass amplified the adsorption capacity and reversible wet compression of hybrid aerogel. The monolayer chemisorption mechanism explored by Langmuir and pseudo-second-order kinetic exhibited a maximum adsorption capacity of 127.5 mg/g. The hybrid aerogel demonstrated higher compatibility for Cd(II) ions as compared to the other coexisted ions in wastewater and manifested a better regeneration potential following four consecutive sorption-desorption cycles. Complexation, electrostatic attraction, ion-exchange and pore entrapment were perhaps major mechanisms involved in the removal of Cd(II) revealed by XPS and FT-IR. This study unveiled a novel avenue for efficient green-synthesized hybrid aerogel that may be sustainably used as an excellent purifying agent for Cd(II) removal from wastewater.

Nanofiber reinforced alginate hydrogel for leak-proof delivery and higher stress loading in nucleus pulposus.

Injectable hydrogels effectively remodel degenerative nucleus pulposus (NP) with a resemblance to the in vivo microenvironment. However, the pressure within the intervertebral disc requires load-bearing implants. The hydrogel must undergo a rapid phase transition upon injection to avoid leakage. In this study, an injectable sodium alginate hydrogel was reinforced with silk fibroin nanofibers with core-shell structures. The nanofiber-embedded hydrogel provided support to adjacent tissues and facilitated cell proliferation. Platelet-rich plasma (PRP) was incorporated into the core-shell nanofibers for sustained release and enhanced NP regeneration. The composite hydrogel exhibited excellent compressive strength and enabled leak-proof delivery of PRP. In rat intervertebral disc degeneration models, radiography and MRI signal intensities were significantly reduced after 8 weeks of injections with the nanofiber-reinforced hydrogel. The biomimetic fiber gel-like structure was constructed in situ, providing mechanical support for NP repair, promoting the reconstruction of the tissue microenvironment, and finally realizing the regeneration of NP.

Biological MWCNT/chitosan composite coating with outstanding anti-corrosion property for implants.

Biocompatible coatings that can protect metal implants have great potential in tissue engineering. In this work, MWCNT/chitosan composite coatings with hydrophobic-hydrophilic asymmetric wettability were facilely prepared by one-step in situ electrodeposition. The resultant composite coating exhibits excellent thermal stability and mechanical strength (0.76 MPa), benefiting from the compact internal structure. The thickness of the coating can be controlled precisely by the amounts of transferred charges. The MWCNT/chitosan composite coating demonstrates a lower corrosion rate due to its hydrophobicity and compact internal structure. Compared with exposed 316 L stainless steel, its corrosion rate is reduced by two orders of magnitude from 3.004 × 10-1 mm/yr to 5.361 × 10-3 mm/yr. The content of iron released from 316 L stainless steel into the simulated body fluid drops to 0.1 mg/L under the protection of the composite coating. In addition, the composite coating enables efficient calcium enrichment from simulated body fluids and promotes the formation of bioapatite layers on the coating surface. This study contributes to furthering the practical application of chitosan-based coatings in implant anticorrosion.

Silk fibroin-chitosan aerogel reinforced by nanofibers for enhanced osteogenic differentiation in MC3T3-E1 cells.

Proper bone scaffolds should be biocompatible, mechanically robust and porous for cell migration. Here, pure silk fibroin (SF)- chitosan (CS) aerogel scaffolds reinforced with different amount of SF nanofibers (SF-CS/NF1%, SF-CS/NF2% and SF-CS/NF3%) are prepared for bone regeneration. Surface morphology and composition were analyzed to ensure successful integration of each component. Incorporating 3 % nanofibers endowed the aerogels with a resistance to 3.5 times the compressive stress of the pure SF-CS aerogels. The benefits of nanofibers were also confirmed by the high porosity of 72.3 ± 1.3 %, the regulated pore size and the high-water uptake ratio of 1770.4 ± 156.8 %. Enhanced cell viability of the aerogel scaffolds was verified with Cell Counting Kit-8 (CCK-8) assays, and confocal microscopy and scanning electron microscopy (SEM) images were taken to assess the cell migration and distribution. The cell differentiation on the aerogel scaffolds was evaluated with enzyme-linked immunosorbent assay (ELISA). Significantly higher level of Collagen type I (Col-I), osteocalcin (OCN), osteopontin (OPN), and alkaline phosphatase (ALP) expression was observed on SF-CS/NF3% aerogels. This biocompatible nanofiber-reinforced aerogel scaffold facilitates osteogenic differentiation by rougher surface, enhanced mechanical strength and well-regulated pores. Thus, as-prepared scaffolds may be further applied in bone regeneration field.

Chitosan/silk fibroin composite bilayer PCL nanofibrous mats for bone regeneration with enhanced antibacterial properties and improved osteogenic potential.

In regenerative medicine and bone tissue engineering, various composite materials are enormously popular, but the final tissue restoration outcome is not always satisfactory. In this study, bilayer-deposited multifunctional nanofiber mats were successfully fabricated with an osteogenic side of silk fibroin/poly (ε-caprolactone) (referred to as SF/PCL) and an antibacterial side of poly (ε-caprolactone)/chitosan (referred to as PCL/CS). The PCL/CS-SF/PCL (referred to as PCSP) mats exhibited biocompatible properties, sufficient hydrophilicity and mechanical properties, as well as a higher breaking strength (3.6 MPa) than the monolayer of SF/PCL mats (1.5 MPa). The antibacterial side of PCSP mats (A-layer) demonstrated ideal antibacterial potency because the survival rate of Escherichia coli (E. coli) (approximately 25 %) and Staphylococcus aureus (S. aureus) (approximately 15 %) were both significantly lower. Subsequently, the plasmid encoding runt related transcription factor 2 (Runx2) was complexed with the osteogenic side of PCSP mats (O-layer) through polyethyleneimine (PEI), thereby enhancing both osteogenesis-related gene expression and the formation of mineralized nodules. Similarly, the implantation of PCSP+Runx2 mats effectively promoted bone tissue generation in vivo. These results indicated the excellent prospects of applying PCSP mats to bone regeneration with gene delivery.