Electrospun multi-chamber core-shell nanofibers and their controlled release behaviors: A review

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.

Natural polymer nanofiber dressings for effective management of chronic diabetic wounds: A comprehensive review

Diabetic wounds present a chronic challenge in effective treatment. Natural polymer nanofiber dressings have emerged as a promising solution due to their impressive biocompatibility, biodegradability, safety, high specific surface area, and resemblance to the extracellular matrix. These qualities make them ideal materials with excellent biological properties and cost-effectiveness. Additionally, they can effectively deliver therapeutic agents, enabling diverse treatment effects. This review offers a comprehensive overview of natural polymer-based nanofibers in diabetic wound dressings. It examines the characteristics and challenges associated with diabetic wounds and the role of natural polymers in facilitating wound healing. The review highlights the preparation, mechanism, and applications of various functional dressings composed of natural polymer nanofibers. Furthermore, it addresses the main challenges and future directions in utilizing natural polymer nanofibers for diabetic wound treatment, providing valuable insights into effective wound management for diabetic patients.

Asymmetric Janus Nanofibrous Agar-Based Wound Dressing Infused with Enhanced Antioxidant and Antibacterial Properties

In the present study, we have developed an agar-based asymmetric Janus nanofibrous wound dressing comprising a support and an electrospun layer with antibacterial and antioxidant properties, respectively, to facilitate healing effectively. The support layer containing agar and silver nitrate was fabricated by using solvent casting for sustained release, combating the dose-dependent cytotoxicity of silver nanoparticles, where nanoparticles were synthesized using a one-pot reduction method. The electrospun layer, fabricated with a mixture of agar and polycaprolactone infused with gallic acid, was electrospun over the support layer to impart antioxidant properties. Characterizations using UV-vis spectroscopy, transmission electron microscopy, scanning electron microscopy, and Fourier transform infrared spectroscopy validated the synthesis of nanoparticles in 10-20 nm diameter and the asymmetric Janus dressing. The developed Janus nanofibrous structure exhibited 98% porosity, excellent fluid-handling properties, a moisture permeability of 1200 g/m2/day, and a water absorption of ∼250%. Moreover, the time-kill assay confirmed potent bacteriostatic effect against Gram-positive and Gram-negative bacteria, and sustained release of silver nanoparticles followed the Korsmeyer-Peppas model. With over 90% free radical scavenging efficacy, 37% degradation in 7 days, and less than 2% hemolysis, the dressings demonstrated exceptional antioxidant, biodegradable, and hemocompatible properties. The biocompatibility assessment further confirmed its cytocompatible efficacy, with more than 79% wound closure in the wound scratch assay. Most importantly, in vivo studies demonstrated the efficacy of the developed Janus dressing, promoting over 97% healing within 12 days of injury with higher epithelial formation. Overall, the in vitro and in vivo assessment of the developed Janus dressing confirmed its potential to function as a versatile and effective material for wound care applications.

Electrospun chitosan//ethylcellulose-vitamin E//ethylcellulose-curcumin tri-chamber eccentric Janus nanofibers for a joint antibacterial and antioxidant performance

Multifunctional materials with both antibacterial and antioxidant properties are highly desired in many scientific applications. The combination of polysaccharide and multi-chamber nanostructures offers a novel perspective for developing antibacterial and antioxidant nanomaterials. In this study, a new kind of tri-chamber eccentric Janus nanostructures (TEJNs) was fabricated through a single-step and straight forward tri-fluid side-by-side electrospinning. The all-in-one TEJNs contained an outer chitosan (CS) chamber, a middle and an inner ethylcellulose (EC)-based chamber loaded with curcumin (Cur) and vitamin E (VE), respectively. The side-by-side multiple-fluid electrospinning processes were implemented robustly and continuously based on a homemade spinneret. Transmission electron microscope and scanning electron microscope evaluations demonstrated the tri-chamber inner structures of TEJNs and the linear morphologies, respectively. The Fourier transform infrared and X-ray diffraction results verified that the components were compatible and coexisted in an amorphous state. In vitro dissolution tests indicated that the TEJNs could provide a sustained release of 90 % of the loaded Cur and VE for 34.30 h and 24.86 h, respectively. Antibacterial and antioxidant experiments demonstrated that the TEJNs were able to provide enhanced antibacterial and antioxidant effects compared to the traditional electrospun homogeneous nanofibers. In the future, the Janus nanofibers can be further developed for several human health applications, such as wound dressings, active food packaging membranes, dental implants and cosmetic films.

Strategies in Electrospun Polymer and Hybrid Scaffolds for Enhanced Cell Integration and Vascularization for Bone Tissue Engineering and Organoids

Addressing the demand for bone substitutes, tissue engineering responds to the high prevalence of orthopedic surgeries worldwide and the limitations of conventional tissue reconstruction techniques. Materials, cells, and growth factors constitute the core elements in bone tissue engineering, influencing cellular behavior crucial for regenerative treatments. Scaffold design, including architectural features and porosity, significantly impacts cellular penetration, proliferation, differentiation, and vascularization. This review discusses the hierarchical structure of bone and the process of neovascularization in the context of biofabrication of scaffolds. We focus on the role of electrospinning and its modifications in scaffold fabrication to improve scaffold properties to enhance further tissue regeneration, for example, by boosting oxygen and nutrient delivery. We highlight how scaffold design impacts osteogenesis and the overall success of regenerative treatments by mimicking the extracellular matrix (ECM). Additionally, we explore the emerging field of bone organoids-self-assembled, three-dimensional (3D) structures derived from stem cells that replicate native bone tissue's architecture and functionality. While bone organoids hold immense potential for modeling bone diseases and facilitating regenerative treatments, their main limitation remains insufficient vascularization. Hence, we evaluate innovative strategies for pre-vascularization and discuss the latest techniques for assessing and improving vascularization in both scaffolds and organoids presenting the most commonly used cell lines and biological models. Moreover, we analyze cutting-edge techniques for assessing vascularization, evaluating their advantages and drawbacks to propose complex solutions. Finally, by integrating these approaches, we aim to advance the development of bioactive materials that promote successful bone regeneration.

Yam Carbon Dots Promote Bone Defect Repair by Modulating Histone Demethylase 4B

Introduction

Chronic apical periodontitis is a typical inflammatory disease of the oral cavity, the pathology is characterized by an inflammatory reaction with bone defects in the periapical area. Chinese medicine is our traditional medicine, Carbon Dots (CDs) are a new type of nanomaterials. The purpose of this study was to prepare Yam Carbon Dots (YAM-CDs) to investigate the mechanism of action of YAM-CDs on bone differentiation in vivo and in vitro.

Methods

We characterized YAM-CDs using transmission electron microscopy (TEM), Fourier Transform Infrared Spectrometer (FTIR), X-Ray Diffraction (XRD) and photoluminescence (PL). CCK-8 assay, Real-time qPCR, and Western Blot were conducted using bone marrow mesenchymal stem cells (BMSCs) to verify that YAM-CDs promote osteoblast differentiation. In addition, we investigated the role of YAM-CDs in promoting bone formation in an inflammatory setting in an in vivo mouse model of cranial defects.

Results

The results of TEM and PL showed that the YAM-CDs mostly consisted of the components C1s, O1s, and N1s. Additionally the average sizes of YAM-CDs were 2-6 nm. The quantum yield was 4.44%, with good fluorescence stability and biosafety. Real-time qPCR and Western blot analysis showed that YAM-CDs promoted osteoblast differentiation under an inflammatory environment by regulating expression of histone demethylase 4B (KDM4B). In vivo, results showed that YAM-CDs effectively repaired cranial bone defects in a mouse model and reduced the expression of inflammatory factors under the action of lipopolysaccharides (LPS).

Conclusion

YAM-CDs promoted the proliferation and differentiation of osteoblasts by regulating the expression of KDM4B to repair cranial bone defects in mice under an LPS-induced inflammatory milieu, which will provide a new idea for the treatment of clinical periapical inflammation and other bone defect diseases.

Research Advances in Electrospun Nanofiber Membranes for Non-Invasive Medical Applications

Non-invasive medical nanofiber technology, characterized by its high specific surface area, biocompatibility, and porosity, holds significant potential in various medical domains, including tissue repair and biosensing. It is increasingly becoming central to healthcare by offering safer and more efficient treatment options for contemporary medicine. Numerous studies have explored non-invasive medical nanofibers in recent years, yet a comprehensive overview of the field remains lacking. In this paper, we provide a comprehensive summary of the applications of electrospun nanofibers in non-invasive medical fields, considering multiple aspects and perspectives. Initially, we introduce electrospinning nanofibers. Subsequently, we detail their applications in non-invasive health, including health monitoring, personal protection, thermal regulation, and wound care, highlighting their critical role in improving human health. Lastly, this paper discusses the current challenges associated with electrospun nanofibers and offers insights into potential future development trajectories.

Application of Electrospun Nanofiber-Based Electrochemical Sensors in Food Safety

Food safety significantly impacts public health and social welfare. Recently, issues such as heavy metal ions, drug residues, food additives, and microbial contamination in food have become increasingly prominent. Electrochemical sensing technology, known for its low cost, simplicity, rapid response, high sensitivity, and excellent selectivity, has been crucial in food safety detection. Electrospun nanofibers, with their high specific surface area, superior mechanical properties, and design flexibility, offer new insights and technical platforms for developing electrochemical sensors. This study introduces the fundamental principles, classifications, and detection mechanisms of electrochemical sensors, along with the principles and classifications of electrospinning technology. The applications of electrospun nanofiber-based electrochemical sensors in food safety detection over the past five years are detailed, and the limitations and future research prospects are discussed. Continuous innovation and optimization are expected to make electrospun nanofiber-based electrochemical sensors a key technology in rapid food safety detection, providing valuable references for expanding their application and advancing food safety detection methods.

Shell Distribution of Vitamin K3 within Reinforced Electrospun Nanofibers for Improved Photo-Antibacterial Performance

Personal protective equipment (PPE) has attracted more attention since the outbreak of the epidemic in 2019. Advanced nano techniques, such as electrospinning, can provide new routes for developing novel PPE. However, electrospun antibacterial PPE is not easily obtained. Fibers loaded with photosensitizers prepared using single-fluid electrospinning have a relatively low utilization rate due to the influence of embedding and their inadequate mechanical properties. For this study, monolithic nanofibers and core-shell nanofibers were prepared and compared. Monolithic F1 fibers comprising polyethylene oxide (PEO), poly(vinyl alcohol-co-ethylene) (PVA-co-PE), and the photo-antibacterial agent vitamin K3 (VK3) were created using a single-fluid blending process. Core-shell F2 nanofibers were prepared using coaxial electrospinning, in which the extensible material PEO was set as the core section, and a composite consisting of PEO, PVA-co-PE, and VK3 was set as the shell section. Both F1 and F2 fibers with the designed structural properties had an average diameter of approximately 1.0 μm, as determined using scanning electron microscopy and transmission electron microscopy. VK3 was amorphously dispersed within the polymeric matrices of F1 and F2 fibers in a compatible manner, as revealed using X-ray diffraction and Fourier transform infrared spectroscopy. Monolithic F1 fibers had a higher tensile strength of 2.917 ± 0.091 MPa, whereas the core-shell F2 fibers had a longer elongation with a break rate of 194.567 ± 0.091%. Photoreaction tests showed that, with their adjustment, core-shell F2 nanofibers could produce 0.222 μmol/L ·OH upon illumination. F2 fibers had slightly better antibacterial performance than F1 fibers, with inhibition zones of 1.361 ± 0.012 cm and 1.296 ± 0.022 cm for E. coli and S. aureus, respectively, but with less VK3. The intentional tailoring of the components and compositions of the core-shell nanostructures can improve the process-structure-performance relationship of electrospun nanofibers for potential sunlight-activated antibacterial PPE.

Reverse Gradient Distributions of Drug and Polymer Molecules within Electrospun Core-Shell Nanofibers for Sustained Release

Core-shell nanostructures are powerful platforms for the development of novel nanoscale drug delivery systems with sustained drug release profiles. Coaxial electrospinning is facile and convenient for creating medicated core-shell nanostructures with elaborate designs with which the sustained-release behaviors of drug molecules can be intentionally adjusted. With resveratrol (RES) as a model for a poorly water-soluble drug and cellulose acetate (CA) and PVP as polymeric carriers, a brand-new electrospun core-shell nanostructure was fabricated in this study. The guest RES and the host CA molecules were designed to have a reverse gradient distribution within the core-shell nanostructures. Scanning electron microscope and transmission electron microscope evaluations verified that these nanofibers had linear morphologies, without beads or spindles, and an obvious core-shell double-chamber structure. The X-ray diffraction patterns and Fourier transform infrared spectroscopic results indicated that the involved components were highly compatible and presented in an amorphous molecular distribution state. In vitro dissolution tests verified that the new core-shell structures were able to prevent the initial burst release, extend the continuous-release time period, and reduce the negative tailing-off release effect, thus ensuring a better sustained-release profile than the traditional blended drug-loaded nanofibers. The mechanism underlying the influence of the new core-shell structure with an RES/CA reverse gradient distribution on the behaviors of RES release is proposed. Based on this proof-of-concept demonstration, a series of advanced functional nanomaterials can be similarly developed based on the gradient distributions of functional molecules within electrospun multi-chamber nanostructures.

Alginate-Based Electrospun Nanofibers and the Enabled Drug Controlled Release Profiles: A Review

Alginate is a natural polymer with good biocompatible properties and is a potential polymeric material for the sustainable development and replacement of petroleum derivatives. However, the non-spinnability of pure alginate solutions has hindered the expansion of alginate applications. With the continuous development of electrospinning technology, synthetic polymers, such as PEO and PVA, are used as co-spinning agents to increase the spinnability of alginate. Moreover, the coaxial, parallel Janus, tertiary and other diverse and novel electrospun fiber structures prepared by multi-fluid electrospinning have found a new breakthrough for the problem of poor spinning of natural polymers. Meanwhile, the diverse electrospun fiber structures effectively achieve multiple release modes of drugs. The powerful combination of alginate and electrostatic spinning is widely used in many biomedical fields, such as tissue engineering, regenerative engineering, bioscaffolds, and drug delivery, and the research fever continues to climb. This is particularly true for the controlled delivery aspect of drugs. This review provides a brief overview of alginate, introduces new advances in electrostatic spinning, and highlights the research progress of alginate-based electrospun nanofibers in achieving various controlled release modes, such as pulsed release, sustained release, biphasic release, responsive release, and targeted release.

Hybrid films loaded with 5-fluorouracil and Reglan for synergistic treatment of colon cancer via asynchronous dual-drug delivery

Combination therapy with oral administration of several active ingredients is a popular clinical treatment for cancer. However, the traditional method has poor convenience, less safety, and low efficiency for patients. The combination of traditional pharmaceutical techniques and advanced material conversion methods can provide new solutions to this issue. In this research, a new kind of hybrid film was created via coaxial electrospraying, followed by a casting process. The films were composed of Reglan and 5-fluorouracil (5-FU)-loaded cellulose acetate (CA) core-shell particles in a polyvinylpyrrolidone (PVP) film matrix. Microscopic observations of these films demonstrated a solid cross section loaded with core-shell particles. X-ray diffraction and Fourier-transform infrared tests verified that the Reglan and 5-FU loaded in the films showed amorphous states and fine compatibilities with the polymeric matrices, i.e., PVP and CA, respectively. In vitro dissolution tests indicated that the films were able to provide the desired asynchronous dual-drug delivery, fast release of Reglan, and sustained release of 5-FU. The controlled release mechanisms were shown to be an erosion mechanism for Reglan and a typical Fickian diffusion mechanism for 5-FU. The protocols reported herein pioneer a new approach for fabricating biomaterials loaded with multiple drugs, each with its own controlled release behavior, for synergistic cancer treatment.

Integrated Janus nanofibers enabled by a co-shell solvent for enhancing icariin delivery efficiency

During the past several decades, nanostructures have played their increasing influences on the developments of novel nano drug delivery systems, among which, double-chamber Janus nanostructure is a popular one. In this study, a new tri-channel spinneret was developed, in which two parallel metal capillaries were nested into another metal capillary in a core-shell manner. A tri-fluid electrospinning was conducted with a solvent mixture as the shell working fluid for ensuring the formation of an integrated Janus nanostructure. The scanning electronic microscopic results demonstrated that the resultant nanofibers had a linear morphology and two distinct compartments within them, as indicated by the image of a cross-section. Fourier Transformation Infra-Red spectra and X-Ray Diffraction patterns verified that the loaded poorly water-soluble drug, i.e. icariin, presented in the Janus medicated nanofibers in an amorphous state, which should be attributed to the favorable secondary interactions between icariin and the two soluble polymeric matrices, i.e. hydroxypropyl methyl cellulose (HPMC) and polyvinylpyrrolidone (PVP). The in vitro dissolution tests revealed that icariin, when encapsulated within the Janus nanofibers, exhibited complete release within a duration of 5 min, which was over 11 times faster compared to the raw drug particles. Furthermore, the ex vivo permeation tests demonstrated that the permeation rate of icariin was 16.2 times higher than that of the drug powders. This improvement was attributed to both the rapid dissolution of the drug and the pre-release of the trans-membrane enhancer sodium lauryl sulfate from the PVP side of the nanofibers. Mechanisms for microformation, drug release, and permeation were proposed. Based on the methodologies outlined in this study, numerous novel Janus nanostructure-based nano drug delivery systems can be developed for poorly water-soluble drugs in the future.

Electrospun medicated gelatin/polycaprolactone Janus fibers for photothermal-chem combined therapy of liver cancer

Liver cancer is a common cancer in the world, and core-shell nanoparticles as a commonly used combination therapy for local tumor ablation, have many shortcomings. In this study, photothermal Janus nanofibers were prepared using a electrospinning technology for tumor treatment, and the products were characterized and in vitro photothermal performance investigated. The micromorphology analysis showed that the photothermic agent CuS and electrospun fibers (loaded with CuS and anticancer drug dihydromyricetin) were successfully prepared, with diameters of 11.58 ± 0.27 μm and 1.19 ± 0.01 μm, respectively. Water contact angle and tensile test indicated that the fiber membranes has a certain hydrophilic adhesion and excellent mechanical strength. The fiber membranes has 808 nm near-infrared laser photothermal heating performance and photothermal stability, and it also has a strong response to the laser that penetrates biological tissue. In addition, in vitro cell culture and in vivo implantation study showed that the fiber membranes could kill HepG2 hepatocellular carcinoma cells combined with photothermal-chem and could be enriched in the implantation area, respectively. Hence, the Janus membranes may be a potential cancer treatment material.

Engineered shapes using electrohydrodynamic atomization for an improved drug delivery

The shapes of micro- and nano-products have profound influences on their functional performances, which has not received sufficient attention during the past several decades. Electrohydrodynamic atomization (EHDA) techniques, mainly include electrospinning and electrospraying, are facile in manipulate their products' shapes. In this review, the shapes generated using EHDA for modifying drug release profiles are reviewed. These shapes include linear nanofibers, round micro-/nano-particles, and beads-on-a-string hybrids. They can be further divided into different kinds of sub-shapes, and can be explored for providing the desired pulsatile release, sustained release, biphasic release, delayed release, and pH-sensitive release. Additionally, the shapes resulted from the organizations of electrospun nanofibers are discussed for drug delivery, and the shapes and inner structures can be considered together for developing novel drug delivery systems. In future, the shapes and the related shape-performance relationships at nanoscale, besides the size, inner structure and the related structure-performance relationships, would further play their important roles in promoting the further developments of drug delivery field. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Preparation and Investigation of Cellulose Acetate/Gelatin Janus Nanofiber Wound Dressings Loaded with Zinc Oxide or Curcumin for Enhanced Antimicrobial Activity

The skin, as the largest organ, serves as a protective barrier against external stimuli. However, when the skin is injured, wound healing becomes a complex process influenced by physiological conditions, bacterial infections, and inflammation. To improve the process of wound healing, a variety of wound dressings with antibacterial qualities have been created. Electrospun nanofibers have gained significant attention in wound dressing research due to their large specific surface area and unique structure. One interesting method for creating Janus-structured nanofibers is side-by-side electrospinning. This work used side-by-side electrospinning to make cellulose acetate/gelatin Janus nanofibers. Curcumin and zinc oxide nanoparticles were added to these nanofibers. We studied Janus nanofibers' physicochemical characteristics and abilities to regulate small-molecule medication release. Janus nanofibers coated with zinc oxide nanoparticles and curcumin were also tested for antibacterial activity. The Janus nanofibers with specified physicochemical characteristics were successfully fabricated. Nanofibers released small-molecule medicines in a controlled manner. Additionally, the Janus nanofibers loaded with curcumin exhibited excellent antibacterial capabilities. This research contributes to the development of advanced wound dressings for promoting wound healing and combating bacterial infections.

Electrospun Fenoprofen/Polycaprolactone @ Tranexamic Acid/Hydroxyapatite Nanofibers as Orthopedic Hemostasis Dressings

Dressings with multiple functional performances (such as hemostasis, promoting regeneration, analgesia, and anti-inflammatory effects) are highly desired in orthopedic surgery. Herein, several new kinds of medicated nanofibers loaded with several active ingredients for providing multiple functions were prepared using the modified coaxial electrospinning processes. With an electrospinnable solution composed of polycaprolactone and fenoprofen as the core working fluid, several different types of unspinnable fluids (including pure solvent, nanosuspension containing tranexamic acid and hydroxyapatite, and dilute polymeric solution comprising tranexamic acid, hydroxyapatite, and polyvinylpyrrolidone) were explored to implement the modified coaxial processes for creating the multifunctional nanofibers. Their morphologies and inner structures were assessed through scanning and transmission electron microscopes, which all showed a linear format without the discerned beads or spindles and a diameter smaller than 1.0 μm, and some of them had incomplete core-shell nanostructures, represented by the symbol @. Additionally, strange details about the sheaths' topographies were observed, which included cracks, adhesions, and embedded nanoparticles. XRD and FTIR verified that the drugs tranexamic acid and fenoprofen presented in the nanofibers in an amorphous state, which resulted from the fine compatibility among the involved components. All the prepared samples were demonstrated to have a fine hydrophilic property and exhibited a lower water contact angle smaller than 40° in 300 ms. In vitro dissolution tests indicated that fenoprofen was released in a sustained manner over 6 h through a typical Fickian diffusion mechanism. Hemostatic tests verified that the intentional distribution of tranexamic acid on the shell sections was able to endow a rapid hemostatic effect within 60 s.