Fabrication and Characterization of Conductive Conjugated Polymer-Coated Antheraea mylitta Silk Fibroin Fibers for Biomedical Applications

Stimuli-Responsive Multiacceptor Conjugated Polymers: Recent Trend and Future Direction

Apart from the visual effects, geometric shapes of materials play an important role in their engineering and biomedical applications. Responsive materials-based patient-specific anatomical models provide better insights into the structure and pathology. Polymers are by far the most utilized class of materials for advanced science and technology. Because of these properties, these polymers have been used as functional coatings, thermoplastics, biomedical materials, separators, and binders for Li-ion batteries, fuel cell membranes, piezoelectric devices, high-quality wires and cables, and so on. Reactive to stimuli because of their unusual electrical characteristics and adaptability, stimuli-responsive multiacceptor conjugated polymers have been a prominent focus of materials science study. These polymers combine several electron-accepting units inside their conjugated backbone, resulting in increased functionality and responsiveness to a variety of stimuli. The production, workings, and wide range of applications of stimuli-responsive multiacceptor conjugated polymers are the focus of this review.

Exploring the protective effect and mechanism of icariside II on the bladder in a rat model of radiation cystitis based on transcriptome sequencing

PURPOSE

Radiation cystitis (RC) is a complex and common complication after radiotherapy for pelvic cancer. Icariside II (ICAII) is a flavonoid compound extracted from Epimedium, a traditional Chinese medicine, with various pharmacological activities. The aim of the present study was to investigate the cysto-protective effects of ICAII in RC rats and its possible mechanisms.

MATERIALS AND METHODS

A rat model of induced radiation cystitis using pelvic X-ray irradiation was used, and bladder function was assessed by bladder volume and bladder leakage point pressure (LPP) after ICAII treatment. HE and Masson stains were used to assess the histopathological changes in the bladder. IL-6, TNF-α, IL-10, IL-4 and IL-1β were measured by ELISA to assess the level of inflammation. The gene-level changes in ICAII-treated RC were observed by transcriptome sequencing, and then the potential targets of action and biological mechanisms were explored by PPI, GO and KEGG enrichment analysis of the differentially expressed genes. Finally, the predicted targets of action were experimentally validated using immunohistochemistry, RT-qPCR, molecular docking and CETSA.

RESULTS

ICAII significantly increased bladder volume and the LPP, ameliorated pathological damage to bladder tissues, decreased the levels of IL-6, TNF-α, and IL-1β, and increased the levels of IL-10 and IL-4 in radiation-injured rats. A total of 90 differentially expressed genes were obtained by transcriptome sequencing, and PPI analysis identified H3F3C, ISG15, SPP1, and LCN2 as possible potential targets of action. GO and KEGG analyses revealed that these differentially expressed genes were mainly enriched in the pathways metabolism of xenobiotics by cytochrome P450, arachidonic acid metabolism, Staphylococcus aureus infection and chemical carcinogenesis - reactive oxygen species. Experimental validation showed that ICAII could significantly increase the expression of H3F3C and ISG15 and inhibit the expression of SPP1 and LCN2. ICAII binds well to H3F3C, ISG15, SPP1 and LCN2, with the best binding ability to H3F3C. Furthermore, ICAII inhibited the protein degradation of H3F3C in bladder epithelial cells.

CONCLUSIONS

ICAII may alleviate the bladder inflammatory response and inhibit the fibrosis process of bladder tissues through the regulation of H3F3C, ISG15, SPP1, and LCN2 targets and has a protective effect on the bladder of radioinjured rats. In particular, H3F3C may be one of the most promising therapeutic targets.

Silk-based intelligent fibers and textiles: structures, properties, and applications

Multifunctional fibers represent a cornerstone of human civilization, playing a pivotal role in numerous aspects of societal development. Natural biomaterials, in contrast to synthetic alternatives, offer environmental sustainability, biocompatibility, and biodegradability. Among these biomaterials, natural silk is favored in biomedical applications and smart fiber technology due to its accessibility, superior mechanical properties, diverse functional groups, controllable structure, and exceptional biocompatibility. This review delves into the intricate structure and properties of natural silk fibers and their extensive applications in biomedicine and smart fiber technology. It highlights the critical significance of silk fibers in the development of multifunctional materials, emphasizing their mechanical strength, biocompatibility, and biodegradability. A detailed analysis of the hierarchical structure of silk fibers elucidates how these structural features contribute to their unique properties. The review also encompasses the biomedical applications of silk fibers, including surgical sutures, tissue engineering, and drug delivery systems, along with recent advancements in smart fiber applications such as sensing, optical technologies, and energy storage. The enhancement of functional properties of silk fibers through chemical or physical modifications is discussed, suggesting broader high-end applications. Additionally, the review addresses current challenges and future directions in the application of silk fibers in biomedicine and smart fiber technologies, underscoring silk's potential in driving contemporary technological innovations. The versatility and sustainability of silk fibers position them as pivotal elements in contemporary materials science and technology, fostering the development of next-generation smart materials.

Microorganism-mediated biodegradation for effective management and/or removal of micro-plastics from the environment: a comprehensive review

Micro- plastics (MPs) pose significant global threats, requiring an environment-friendly mode of decomposition. Microbial-mediated biodegradation and biodeterioration of micro-plastics (MPs) have been widely known for their cost-effectiveness, and environment-friendly techniques for removing MPs. MPs resistance to various biocidal microbes has also been reported by various studies. The biocidal resistance degree of biodegradability and/or microbiological susceptibility of MPs can be determined by defacement, structural deformation, erosion, degree of plasticizer degradation, metabolization, and/or solubilization of MPs. The degradation of microplastics involves microbial organisms like bacteria, mold, yeast, algae, and associated enzymes. Analytical and microbiological techniques monitor microplastic biodegradation, but no microbial organism can eliminate microplastics. MPs can pose environmental risks to aquatic and human life. Micro-plastic biodegradation involves fragmentation, assimilation, and mineralization, influenced by abiotic and biotic factors. Environmental factors and pre-treatment agents can naturally degrade large polymers or induce bio-fragmentation, which may impact their efficiency. A clear understanding of MPs pollution and the microbial degradation process is crucial for mitigating its effects. The study aimed to identify deteriogenic microorganism species that contribute to the biodegradation of micro-plastics (MPs). This knowledge is crucial for designing novel biodeterioration and biodegradation formulations, both lab-scale and industrial, that exhibit MPs-cidal actions, potentially predicting MPs-free aquatic and atmospheric environments. The study emphasizes the urgent need for global cooperation, research advancements, and public involvement to reduce micro-plastic contamination through policy proposals and improved waste management practices.

Understanding Molecular Mechanisms and Identifying Key Processes in Chronic Radiation Cystitis

Chronic radiation cystitis (CRC) is a consequence of pelvic radiotherapy and affects 5–10% of patients. The pathology of CRC is without curative treatment and is characterized by incontinence, pelvic pain and hematuria, which severely degrades patients’ quality of life. Current management strategies rely primarily on symptomatic measures and have certain limitations. Thanks to a better understanding of the pathophysiology of radiation cystitis, studies targeting key manifestations such as inflammation, neovascularization and cell atrophy have emerged and are promising avenues for future treatment. However, the mechanisms of CRC are still better described in animal models than in human models. Preclinical studies conducted to elucidate the pathophysiology of CRC use distinct models and are most often limited to specific processes, such as fibrosis, vascular damage and inflammation. This review presents a synthesis of experimental studies aimed at improving our understanding of the molecular mechanisms at play and identifying key processes in CRC.

Conductive Biomaterials as Bioactive Wound Dressing for Wound Healing and Skin Tissue Engineering

Conductive biomaterials based on conductive polymers, carbon nanomaterials, or conductive inorganic nanomaterials demonstrate great potential in wound healing and skin tissue engineering, owing to the similar conductivity to human skin, good antioxidant and antibacterial activities, electrically controlled drug delivery, and photothermal effect. However, a review highlights the design and application of conductive biomaterials for wound healing and skin tissue engineering is lacking. In this review, the design and fabrication methods of conductive biomaterials with various structural forms including film, nanofiber, membrane, hydrogel, sponge, foam, and acellular dermal matrix for applications in wound healing and skin tissue engineering and the corresponding mechanism in promoting the healing process were summarized. The approaches that conductive biomaterials realize their great value in healing wounds via three main strategies (electrotherapy, wound dressing, and wound assessment) were reviewed. The application of conductive biomaterials as wound dressing when facing different wounds including acute wound and chronic wound (infected wound and diabetic wound) and for wound monitoring is discussed in detail. The challenges and perspectives in designing and developing multifunctional conductive biomaterials are proposed as well.

Conductive Polymeric-Based Electroactive Scaffolds for Tissue Engineering Applications: Current Progress and Challenges from Biomaterials and Manufacturing Perspectives

The practice of combining external stimulation therapy alongside stimuli-responsive bio-scaffolds has shown massive potential for tissue engineering applications. One promising example is the combination of electrical stimulation (ES) and electroactive scaffolds because ES could enhance cell adhesion and proliferation as well as modulating cellular specialization. Even though electroactive scaffolds have the potential to revolutionize the field of tissue engineering due to their ability to distribute ES directly to the target tissues, the development of effective electroactive scaffolds with specific properties remains a major issue in their practical uses. Conductive polymers (CPs) offer ease of modification that allows for tailoring the scaffold's various properties, making them an attractive option for conductive component in electroactive scaffolds. This review provides an up-to-date narrative of the progress of CPs-based electroactive scaffolds and the challenge of their use in various tissue engineering applications from biomaterials perspectives. The general issues with CP-based scaffolds relevant to its application as electroactive scaffolds were discussed, followed by a more specific discussion in their applications for specific tissues, including bone, nerve, skin, skeletal muscle and cardiac muscle scaffolds. Furthermore, this review also highlighted the importance of the manufacturing process relative to the scaffold's performance, with particular emphasis on additive manufacturing, and various strategies to overcome the CPs' limitations in the development of electroactive scaffolds.

Redox Polymers for Tissue Engineering

This review will focus on the targeted design, synthesis and application of redox polymers for use in regenerative medicine and tissue engineering. We define redox polymers to encompass a variety of polymeric materials, from the multifunctional conjugated conducting polymers to graphene and its derivatives, and have been adopted for use in the engineering of several types of stimulus responsive tissues. We will review the fundamental properties of organic conducting polymers (OCPs) and graphene, and how their properties are being tailored to enhance material - biological interfacing. We will highlight the recent development of high-resolution 3D fabrication processes suitable for biomaterials, and how the fabrication of intricate scaffolds at biologically relevant scales is providing exciting opportunities for the application of redox polymers for both in-vitro and in-vivo tissue engineering. We will discuss the application of OCPs in the controlled delivery of bioactive compounds, and the electrical and mechanical stimulation of cells to drive behaviour and processes towards the generation of specific functional tissue. We will highlight the relatively recent advances in the use of graphene and the exploitation of its physicochemical and electrical properties in tissue engineering. Finally, we will look forward at the future of organic conductors in tissue engineering applications, and where the combination of materials development and fabrication processes will next unite to provide future breakthroughs.

Bioprinting Neural Systems to Model Central Nervous System Diseases

To date, pharmaceutical progresses in central nervous system (CNS) diseases are clearly hampered by the lack of suitable disease models. Indeed, animal models do not faithfully represent human neurodegenerative processes and human in vitro 2D cell culture systems cannot recapitulate the in vivo complexity of neural systems. The search for valuable models of neurodegenerative diseases has recently been revived by the addition of 3D culture that allows to re-create the in vivo microenvironment including the interactions among different neural cell types and the surrounding extracellular matrix (ECM) components. In this review, the new challenges in the field of CNS diseases in vitro 3D modeling are discussed, focusing on the implementation of bioprinting approaches enabling positional control on the generation of the 3D microenvironments. The focus is specifically on the choice of the optimal materials to simulate the ECM brain compartment and the biofabrication technologies needed to shape the cellular components within a microenvironment that significantly represents brain biochemical and biophysical parameters.

Double coating of graphene oxide–polypyrrole on silk fibroin scaffolds for neural tissue engineering

The desired scaffolds for neural tissue engineering need to have electrical conductivity. In this study, we doubly coated graphene oxide and polypyrrole on silk fibroin scaffolds (SF@GO-PPY) by a facile method to improve its electrical conductivity. The graphene oxide–polypyrrole double coating was distributed homogeneously on silk fibroin scaffolds. Compared with silk fibroin scaffolds, the SF@GO-PPY scaffold showed higher electrical conductivity, electrochemical property, mechanical property, and thermal stability. The π–π stacking interaction between polypyrrole and graphene oxide might contribute to the superior conductive and electrochemical property of the SF@GO-PPY scaffold. Moreover, in vitro cell experiment carried out on SH-SY5Y cells showed no cytotoxicity of all the scaffolds. Thus, the results indicated that the SF@GO-PPY scaffold might be a suitable candidate for the application in neural regeneration field.

Facile fabrication of electroconductive natural silk composites by microscale manipulation

Silk/PPy composites with high biocompatibility and electroconductivity were fabricated via the enhanced loading capacity of silk fibers.

Novel conductive polypyrrole/silk fibroin scaffold for neural tissue repair

Three dimensional (3D) bioprinting, which involves depositing bioinks (mixed biomaterials) layer by layer to form computer-aided designs, is an ideal method for fabricating complex 3D biological structures. However, it remains challenging to prepare biomaterials with micro-nanostructures that accurately mimic the nanostructural features of natural tissues. A novel nanotechnological tool, electrospinning, permits the processing and modification of proper nanoscale biomaterials to enhance neural cell adhesion, migration, proliferation, differentiation, and subsequent nerve regeneration. The composite scaffold was prepared by combining 3D bioprinting with subsequent electrochemical deposition of polypyrrole and electrospinning of silk fibroin to form a composite polypyrrole/silk fibroin scaffold. Fourier transform infrared spectroscopy was used to analyze scaffold composition. The surface morphology of the scaffold was observed by light microscopy and scanning electron microscopy. A digital multimeter was used to measure the resistivity of prepared scaffolds. Light microscopy was applied to observe the surface morphology of scaffolds immersed in water or Dulbecco's Modified Eagle's Medium at 37°C for 30 days to assess stability. Results showed characteristic peaks of polypyrrole and silk fibroin in the synthesized conductive polypyrrole/silk fibroin scaffold, as well as the structure of the electrospun nanofiber layer on the surface. The electrical conductivity was 1 × 10-5-1 × 10-3 S/cm, while stability was 66.67%. A 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay was employed to measure scaffold cytotoxicity in vitro. Fluorescence microscopy was used to observe EdU-labeled Schwann cells to quantify cell proliferation. Immunohistochemistry was utilized to detect S100β immunoreactivity, while scanning electron microscopy was applied to observe the morphology of adherent Schwann cells. Results demonstrated that the polypyrrole/silk fibroin scaffold was not cytotoxic and did not affect Schwann cell proliferation. Moreover, filopodia formed on the scaffold and Schwann cells were regularly arranged. Our findings verified that the composite polypyrrole/silk fibroin scaffold has good biocompatibility and may be a suitable material for neural tissue engineering.

Physico-chemical characterization of Antheraea mylitta silk mats for wound healing applications

In the field of plastic reconstructive surgery, development of new innovative matrices for skin repair is in demand. The ideal biomaterial should promote attachment, proliferation and growth of cells. Additionally, it should degrade in an appropriate time period without releasing harmful substances, not exerting a pathological immune response. The materials used should display optimized mechanical properties to sustain cell growth and limit scaffold contraction. Wound healing is a biological process directed towards restoration of tissue that has suffered an injury. An important phase of wound healing is the generation of a basal epithelium wholly replacing the epidermis of the wound. Wild silk from Antheraea mylitta meets these demands to a large extent. To evaluate the effects of the treatment, Antheraea mylitta and Bombyx mori samples were characterized by SEM-EDX, FT-IR, XRD and TGA-DSC techniques. Preliminary cell growth behavior was carried out by culturing epidermal cells and proliferation was quantified via viability assay. Moreover, Antheraea mylitta possesses excellent cell-adhesive capability, effectively promoting cell attachment and proliferation. Antheraea mylitta serves as a delivery vehicle for cells. With all these unique features, it is expected that Antheraea mylitta mat will have wide utility in the areas of tissue engineering and regenerative medicine.