Smart multi stimuli-responsive electrospun nanofibers for on-demand drug release

Electrostimulation combined with biodegradable electroactive oriented nanofiber polycaprolactone/gelatin/carbon nanotube to accelerate wound healing

Wound healing is a complex but precise physiological process. Howener, existing treatments are often difficult to meet the needs of different wound healing. With the background that exogenous electrical stimulation (ES) has been proven to be effective in regulating cell behavior, we constructed a electroactive wound dressing derived from carbon nanotubes (CNT) by electrospinning technology. The scaffold has a moderate hydrophilicity, which benefits to collecting of effusion, adhering to the wound site, and safely removing. Furthermore, the oriented structure has the potential to promote cell oriented growth, while the coupling of endogenous electric field (EFs) and ES could effectively regulate the phenotype of macrophages and reshape the immune microenvironment. At the same time, the active electrical stimulation promotes the secretion of active factors and the proliferation and migration of fibroblasts and endothelial cells. In vivo assays further confirm that PCL/GE/CNT combined ES strategy can significantly inhibit the early inflammatory response, while promoting vascular regeneration and collagen deposition. RNA sequencing analysis is used to reveal the mechanism at the molecular level. Overall, this study employed a composite strategy of combining CNT with moderately hydrophilic biocompatible nanofibers to achieve ES delivery simply and effectively, significantly improving tissue engineering outcomes. This innovative strategy provides a feasible approach for efficient wound repair, and provides an important experimental basis and theoretical guidance for future development in the field of skin tissue engineering.

Advanced applications of smart electrospun nanofibers in cancer therapy: With insight into material capabilities and electrospinning parameters

Cancer remains a major global health challenge, and despite available treatments, its prognosis remains poor. Recently, researchers have turned their attention to intelligent nanofibers for cancer drug delivery. These nanofibers exhibit remarkable capabilities in targeted and controlled drug release. Their inherent characteristics, such as a high surface area-to-volume ratio, make them attractive candidates for drug delivery applications. Smart nanofibers can release drugs in response to specific stimuli, including pH, temperature, magnetic fields, and light. This unique feature not only reduces side effects but also enhances the overall efficiency of drug delivery systems. Electrospinning, a widely used method, allows the precision fabrication of smart nanofibers. Its advantages include high efficiency, user-friendliness, and the ability to control various manufacturing parameters. In this review, we explore the latest developments in producing smart electrospun nanofibers for cancer treatment. Additionally, we discuss the materials used in manufacturing these nanofibers and the critical parameters involved in the electrospinning process.

Tailoring biomaterials for skin anti-aging

Skin aging is the phenomenon of degenerative changes in the structure and function of skin tissues over time and is manifested by a gradual loss of skin elasticity and firmness, an increased number of wrinkles, and hyperpigmentation. Skin anti-aging refers to a reduction in the skin aging phenomenon through medical cosmetic technologies. In recent years, new biomaterials have been continuously developed for improving the appearance of the skin through mechanical tissue filling, regulating collagen synthesis and degradation, inhibiting pigmentation, and repairing the skin barrier. This review summarizes the mechanisms associated with skin aging, describes the biomaterials that are commonly used in medical aesthetics and their possible modes of action, and discusses the application strategies of biomaterials in this area. Moreover, the synergistic effects of such biomaterials and other active ingredients, such as stem cells, exosomes, growth factors, and antioxidants, on tissue regeneration and anti-aging are evaluated. Finally, the possible challenges and development prospects of biomaterials in the field of anti-aging are discussed, and novel ideas for future innovations in this area are summarized.

Electrospun collagen/chitosan composite fibrous membranes for accelerating wound healing

The protein-polysaccharide nanofibers have attracted intensive attention in promoting wound healing, due to their components and nanoscale fibrous structure that mimics the native extracellular matrix (ECM). For the full-thickness wounds, in addition to promoting healing, hemostatic property and antibacterial activity are also of critical importance. However, currently, protein-polysaccharide-based nanofiber membranes exhibit poor mechanical properties, lack inherent hemostatic and antibacterial capabilities, as well as the ability to promote tissue repair. In this study, we developed composited membranes, which were composed of collagen (Col) and chitosan (Chs), through solvent alteration and post-processing, the membranes showed enhanced stability under physiological conditions, proper hydrophilic performance and improved mechanical property. Appropriated porosity and water vapor transmission rate, which benefit to wound healing, were detected among all the membranes except for Col membrane. Aimed at wound dressing, hemocompatibility, antibacterial activity and cell proliferation of the electrospun membranes were evaluated. The results indicated that the Col/Chs composited membranes exhibited superior blood clotting capacity, and the membranes with Chs exceeding 60% possessed sufficient antibacterial activity. Moreover, compared with Chs nanofibers, significant increase in cell grow was detected in Col/Chs (1:3) membrane. Taken together, the electrospun membrane with multiple properties favorable to wound healing, superior blood coagulation, sufficient antibacterial performance and promoting cell proliferation property make it favorable candidate for full-thickness skin wound healing.

Fibrous Structures: An Overview of Their Responsiveness to External Stimuli towards Intended Application

In recent decades, the interest in responsive fibrous structures has surged, propelling them into diverse applications: from wearable textiles that adapt to their surroundings, to filtration membranes dynamically altering selectivity, these structures showcase remarkable versatility. Various stimuli, including temperature, light, pH, electricity, and chemical compounds, can serve as triggers to unleash physical or chemical changes in response. Processing methodologies such as weaving or knitting using responsive yarns, electrospinning, as well as coating procedures, enable the integration of responsive materials into fibrous structures. They can respond to these stimuli, and comprise shape memory materials, temperature-responsive polymers, chromic materials, phase change materials, photothermal materials, among others. The resulting effects can manifest in a variety of ways, from pore adjustments and altered permeability to shape changing, color changing, and thermal regulation. This review aims to explore the realm of fibrous structures, delving into their responsiveness to external stimuli, with a focus on temperature, light, and pH.

Enhanced heterogeneous interface to construct intelligent conductive hydrogel gas sensor for individualized treatment of infected wounds

In this study, we developed an enhanced heterogeneous interface intelligent conductive hydrogel NH3 sensor for individualized treatment of infected wounds. The sensor achieved monitoring, self-diagnosis, and adaptive gear adjustment functions. The PPY@PDA/PANI(3/6) sensor had a minimum NH3 detection concentration of 50 ppb and a response value of 2.94 %. It also had a theoretical detection limit of 49 ppt for infected wound gas. The sensor exhibited a fast response time of 23.2 s and a recovery time of 42.9 s. Tobramycin (TOB) was encapsulated in a self-healing QCS/OD hydrogel formed by quaternized chitosan (QCS) and oxidized dextran (OD), followed by the addition of polydopamine-coated polypyrrole nanowires (PPY@PDA) and polyaniline (PANI) to prepare electrically conductive drug-loaded PPY@PDA/PANI hydrogels. The drug-loaded PPY@PDA/PANI hydrogel was combined with a PANI/PVDF membrane to form an enhanced heterogeneous interfacial PPY@PDA/PANI/PVDF-based sensor, which could adaptively learn the individual wound ammonia response and adjust the speed of drug release from the PPY@PDA/PANI hydrogel with electrical stimulation. Drug release and animal studies demonstrated the efficacy of the PPY@PDA/PANI hydrogel in inhibiting infection and accelerating wound healing. In conclusion, the gas-sensitive conductive hydrogel sensing system is expected to enable intelligent drug delivery and provide personalized treatment for complex wound management.

Construction of cellulose acetate-based composite nanofiber films with effective antibacterial and filtration properties

In recent years, the safety of public health has attracted more and more attention. In order to avoid the spread of bacteria and reduce the diseases caused by their invasion of the human body, novel filtration and antibacterial materials have attracted more and more attention. In this work, the antibacterial agents silver nanoparticles (AgNPs) and cetylpyridine bromide (CPB) were introduced into a cellulose acetate (CA) nanofiber film by electrospinning technology to prepare CA-based composite films with good antibacterial and filtration properties. The results of the antibacterial test of the composite nanofiber films showed that AgNPs and CPB had synergistic antibacterial effects and exhibited good antibacterial properties against a variety of bacteria. In addition, in vitro cytotoxicity, skin irritation and skin sensitization experiments proved that the CA/AgNPs, CA/CPB and CA/CPB/AgNPs films produced no skin irritation or sensitization in the short term. These are expected to become potential materials for the preparation of new antibacterial masks. This work provides a new idea for developing materials with good antibacterial properties for enhancing protection via filtration masks.

Dual-crosslinked methacrylamide chitosan/poly(ε-caprolactone) nanofibers sequential releasing of tannic acid and curcumin drugs for accelerating wound healing

The objective of this research study is to develop novel composite nanofibers based on methacrylamide chitosan (ChMA)/poly(ε-caprolactone) (PCL) materials by the dual crosslinking and coaxial-electrospinning strategies. The prepared ChMA/PCL composite nanofibers can sequentially deliver tannic acid and curcumin drugs to synergistically inhibit bacterial reproduction and accelerate wound healing. The rapid delivery of tannic acid is expected to inhibit pathogenic microorganisms and accelerate epithelialization in the early stage, while the slow and sustained release of curcumin is with the aim of relieving chronic inflammatory response and inducing dermal tissue maturation in the late stage. Meanwhile, dual-drugs sequentially released from the membrane exhibited a DPPH free radical scavenging rate of ca. 95 % and an antibacterial rate of above 85 %. Moreover, the membrane possessed great biocompatibility in vitro and significantly inhibited the release of pro-inflammatory factors (IL-1β and TNF-α) in vivo. Animal experiments showed that the composite membrane by means of the synergistic effect of polyphenol drugs and ChMA nanofibers, could significantly alleviate macrophage infiltration and accelerate the healing process of wounds. From the above, the as-prepared ChMA-based membrane with a stage-wise release pattern of drugs could be a promising bioengineered construct for wound healing application.

Multifunctional Electrospun Nanofibers for Biosensing and Biomedical Engineering Applications

Nanotechnology is experiencing unprecedented developments, leading to the advancement of functional nanomaterials. The properties that stand out include remarkable porosity, high-specific surface area, excellent loading capacity, easy modification, and low cost make electrospun nanofibers. In the biomedical field, especially in biosensors, they exhibit amazing potential. This review introduces the principle of electrospinning, describes several structures and biomaterials of electrospun nanofibers used for biomedicine, and summarizes the applications of this technology in biosensors and other biomedical applications. In addition, the technical challenges and limitations of electrospinning for biomedicine are discussed; however, more research work is needed to elucidate its full potential.