Influence of the drug compatibility with polymer solution on the release kinetics of electrospun fiber formulation

Docetaxel-Loaded Electrospun Nanofibrous Mats for Local Chemotherapy Targeting Positive Surgical Margins in Prostate Cancer

Positive surgical margins following radical prostatectomy significantly contribute to tumor recurrence. While systemic chemotherapy demonstrates limited efficacy in this context, local chemotherapy drug delivery systems based on nanomaterials offer promising strategies to address this issue by modifying drug release kinetics and distribution, thereby enhancing antitumor effects while minimizing the toxicities associated with systemic chemotherapy. In this study, we utilized electrospun nanofibrous mats loaded with docetaxel for sustained drug delivery. In vitro experiments demonstrated that these implantable drug-loaded nanofibrous mats effectively inhibited prostate cancer cell growth, induced cell cycle arrest, and promoted apoptosis. In animal models, these drug-loaded nanofibrous mats exhibited prominent therapeutic effects on positive surgical margins postoperatively. Importantly, docetaxel-loaded nanofibrous mats modulated the tumor immune microenvironment by suppressing M2-like macrophages, increasing the ratio between M1- and M2-like macrophages, and enhancing CD8+ T-cell infiltration. Local administration significantly reduced systemic toxicity compared to systemic chemotherapy. In summary, we developed an implantable electrospun drug-loaded nanofibrous mat for localized docetaxel delivery, which offers a prospective strategy for managing positive surgical margins after surgery.

Improved Mechanical Stability and Regulated Gentamicin-Release of Polyvinyl Alcohol/Chitosan Nanofiber Membranes via Heat Treatment

For wound dressing applications, nanofiber membranes must have adequate mechanical strength when cultured in vitro for cell ingrowth and matrix production, and the ability to withstand stresses in vivo. Moreover, effective polymeric drug carriers must also regulate and prolong drug release while preserving drug stability. This study addresses these requirements by utilizing heat treatment (100°C for 2 h) to improve the mechanical stability and regulated drug-release characteristics of electrospun gentamicin-loaded polyvinyl alcohol/chitosan (PVA/CS) nanofiber membranes. Electrospinning solutions with varying gentamicin concentrations produced defect-free and uniform nanofibers. The nanofiber membranes were characterized using scanning electron microscopy, Fourier transform infrared spectroscopy, and tensile testing, and their in vitro biodegradation and drug-release behavior were investigated. Tensile results revealed that heat treatment improved the mechanical strength of PVA and PVA/CS nanofibers, with gentamicin-loaded samples maintaining stability post-treatment. Gentamicin in the heat-treated nanofiber membranes exhibited controlled drug-release profiles, with reduced initial burst release and sustained release for 25 h. Furthermore, drug release was found to occur through the Fickian diffusion mechanism based on the Korsmeyer-Peppas model. These findings demonstrate that heat treatment is effective for achieving mechanical stability and regulated drug release, making it a safe alternative to chemical cross-linking for the biomedical applications of drug-loaded PVA/CS nanofiber membranes.

Environmental release behavior, cell toxicity and intracellular distribution of novel biodegradable plastic materials

In response to the increasingly severe issue of plastic waste, biodegradable plastics have garnered extensive attention as a potential alternative to traditional plastics. Among these materials, biodegradable plastics hold a dominant position. The objective of this study was to assess the environmental risks of five commercially available biodegradable plastics: polyglycolic acid (PGA), polylactic acid (PLA), poly(butylene succinate) (PBS), poly(butylene carbonate) (PBC), and poly(butylene adipate-co-terephthalate) (PBAT). The evaluation included their physical properties, microplastic release behavior, and cytotoxicity. In addition, the effect of age process on the environmental behavior of biodegradable plastic materials was further investigated. The results revealed that PGA and PBS exhibited lower risks in terms of microplastic release, whereas PLA demonstrated higher environmental mobility. Further cytotoxicity experiments indicated that PLA and PBS exerted significant toxic effects on human cell lines, including human normal liver cells (LO2), human monocytic leukemia cells (THP-1), human umbilical vein endothelial cells (HUVECs), and human colon carcinoma cells (Caco-2). Additionally, this study utilized Nile Red labeling to observe the co-culture system of PGA with THP-1 cells, uncovering that THP-1 cells gradually engulfed and internalized PGA microplastics over time. This finding provides new insights into the potential mechanism by which microplastics promote cell proliferation. Moreover, we also found that the aging process partially reduced the cytotoxicity of PGA, but had little effect on environmental mobility. Considering the comprehensive research findings, PGA is considered an ideal material for large-scale applications due to its low cytotoxicity and environmental risks. In contrast, the environmental safety of other types of plastics requires more comprehensive risk assessment to determine their suitability. This study provides significant scientific evidence for the environmental impact assessment of biodegradable plastics and plays a crucial role in promoting the development of sustainable plastic alternatives.

Electrospun nanofibers: Focus on local therapeutic delivery targeting infectious disease

Whether it be due to genetic variances, lack of patient adherence, or sub-optimal drug metabolism, the risk of antibiotic resistance from medications administered systemically continues to pose significant challenges to fighting infectious diseases. Ideally, infections would be treated locally for maximal efficacy while minimizing off-target effects. The electrospinning of biomaterials has recently facilitated the creation of electrospun nanofibers as an alternative delivery vehicle for local treatment. This review describes electrospun nanofiber applications to locally target various infectious diseases. Electrospinning is first reviewed as a method to fabricate nanofiber platforms with advantageous properties for developing drug delivery systems. The emergence of artificial intelligence to facilitate the development of nanofiber formulations and the evaluation of operating parameters to customize therapeutic behavior are described. A range of biomaterials utilized for electrospinning nanofibers is summarized in the context of properties suitable for drug delivery, particularly to treat infectious diseases. The current body of literature for electrospun nanofiber applications to tackle infectious diseases, including sexually transmitted infections, oral infections, and Staphylococcus Aureus infections is described. We anticipate that the advantages of electrospun nanofibers to facilitate targeted application while minimizing antibiotic resistance will substantially expand their clinical use in coming years.

Dexamethasone acetate loaded poly(ε-caprolactone) nanofibers for rat corneal chemical burn treatment

Topical eye drop approaches to treat ocular inflammation in dry eyes often face limitations such as low efficiency and short duration of drug delivery. Nanofibers serve to overcome the limitation of the short duration of action of topical eye drops used against ocular inflammation in dry eyes. Several attempts to develop suitable nanofibers have been made; however, there is no ideal solution. Here, we developed polycaprolactone (PCL) nanofibers loaded with dexamethasone acetate (DEX), prepared by electrospinning, as a potential ocular drug delivery platform for corneal injury treatment. Thirty-nine Sprague Dawley rats (7 weeks old males) were divided into four treatment groups after alkaline burns of the cornea; negative control (no treatment group); dexamethasone eyedrops (DEX group); PCL fiber (PCL group); dexamethasone loaded PCL (PCL + DEX group). We evaluated therapeutic efficacy of PCL + DEX by examining the epithelial wound healing effect, the extent of corneal opacity and neovascularization. Additionally, various inflammatory factors, including IL-1β, were investigated through immunochemistry, western blot analysis, and quantitative real-time RT-PCR (qRT-PCR). PCL + DEX group showed histologically alleviated signs of corneal inflammation compared with DEX group, which showed a decrease in IL-1β and MMP9 in the corneal stroma. The quantitative expression on day 1 after alkaline burn of pro-inflammatory markers, including IL-1β and IL-6, in the PCL + DEX group was significantly lower than that in the DEX group. Notably, PCL + DEX treatment significantly suppressed neovascularization, and enhanced the anti-inflammatory function of DEX during the acute phase of ocular inflammation. Collectively, these findings suggest that PCL + DEX may be a promising approach to effective drug delivery in corneal burn injuries.

Silybin-Functionalized PCL Electrospun Fibrous Membranes for Potential Pharmaceutical and Biomedical Applications

Silybin is a natural flavonolignan with potential anticancer, antioxidant, and hepatoprotective properties. In the present study, various loadings of silybin (1, 3, and 5 wt%) were encapsulated in poly-ε-caprolactone (PCL) fibers by electrospinning, in order to produce new pharmaceutical composites with improved bioactive and drug delivery properties. The morphological characteristics of the composite fibrous structures were evaluated by scanning electron microscopy (SEM), and the encapsulation efficiency and the release rate of silybin were quantified using a UV-Vis spectrophotometer. The analysis of the membranes' thermal behavior by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) revealed the existence of interaction between PCL and silybin. An investigation of the cytocompatibility of the composite membranes revealed that normal cells displayed an unimpeded proliferation in the respective silybin concentrations; however, tumor cell growth demonstrated a dose-dependent inhibition. Furthermore, an effective antioxidant activity against hydrogen peroxide-induced oxidative stress in HEK-293 cells was observed for the prepared electrospun fibrous mats.

Cancer Treatment Using Nanofibers: A Review

Currently, the number of patients with cancer is expanding consistently because of a low quality of life. For this reason, the therapies used to treat cancer have received a lot of consideration from specialists. Numerous anticancer medications have been utilized to treat patients with cancer. However, the immediate utilization of anticancer medicines leads to unpleasant side effects for patients and there are many restrictions to applying these treatments. A number of polymers like cellulose, chitosan, Polyvinyl Alcohol (PVA), Polyacrylonitrile (PAN), peptides and Poly (hydroxy alkanoate) have good properties for the treatment of cancer, but the nanofibers-based target and controlled drug delivery system produced by the co-axial electrospinning technique have extraordinary properties like favorable mechanical characteristics, an excellent release profile, a high surface area, and a high sponginess and are harmless, bio-renewable, biofriendly, highly degradable, and can be produced very conveniently on an industrial scale. Thus, nanofibers produced through coaxial electrospinning can be designed to target specific cancer cells or tissues. By modifying the composition and properties of the nanofibers, researchers can control the release kinetics of the therapeutic agent and enhance its accumulation at the tumor site while minimizing systemic toxicity. The core-shell structure of coaxial electrospun nanofibers allows for a controlled and sustained release of therapeutic agents over time. This controlled release profile can improve the efficacy of cancer treatment by maintaining therapeutic drug concentrations within the tumor microenvironment for an extended period.

Synchronized Codelivery of Combination Chemotherapies Intratumorally Using a Lipidic Lyotropic Liquid Crystal System

In this work, an injectable in situ depot-forming lipidic lyotropic liquid crystal (L3C) system is developed to codeliver a precisely synchronized combination of chemotherapeutics intratumorally. The developed L3C system is composed of amphiphilic lipids and surfactants, including monoolein, phosphatidylcholine, tocopherol acetate, and d-α-tocopherol polyethylene glycol 1000 succinate. Owing to its amphiphilic nature, the developed formulation can coaccommodate both hydrophobic and hydrophilic chemotherapeutic moieties simultaneously. The study presents a proof of concept by designing a combination chemotherapy regimen in vitro and demonstrating its in vivo translation using doxorubicin and paclitaxel as model hydrophilic and hydrophobic drug moieties, respectively. The synchronized combination of the two chemotherapeutics with maximum synergistic activity was identified, coloaded in the developed L3C system at predefined stoichiometric ratios, and evaluated for antitumor efficacy in the 4T1 breast tumor model in BALB/c mice. The drug-loaded L3C formulation is a low-viscosity injectable fluid with a lamellar phase that transforms into a hexagonal mesophase depot system upon intratumoral injection. The drug-loaded depot system locally provides sustained intratumoral delivery of the chemotherapeutics combination at their precisely synchronized ratio for over a period of one month. Results demonstrate that the exposure of the tumor to the precisely synchronized intratumoral chemotherapeutics combination via the developed L3C system resulted in significantly higher antitumor activity and reduced cardiotoxicity compared to the unsynchronized combination chemotherapy or the synchronized but uncoordinated drug delivery administered by a conventional intravenous route. These findings demonstrate the potential of the developed L3C system for achieving synchronized codelivery of the chemotherapeutics combination intratumorally and improving the efficacy of combination chemotherapy.

Electrospun Chitosan-Based Nanofibrous Coating for the Local and Sustained Release of Vancomycin

As the population ages, the number of vascular surgery procedures performed increases. Older adults often have multiple comorbidities, such as diabetes and hypertension, that increase the risk of complications from vascular surgery including vascular graft infection (VGI). VGI is a serious complication with significant morbidity, mortality, and healthcare costs. Here, we aimed to develop a nanofibrous chitosan-based coating for vascular grafts loaded with different concentrations of the vancomycin antibiotic vancomycin (VAN). Blending chitosan with poly(vinyl alcohol) or poly(ethylene oxide) copolymers improved solubility and ease of spinning. Thermal gravimetric analysis and Fourier transform infrared spectroscopy confirmed the presence of VAN in the nanofibrous membranes. Kinetics of VAN release from the nanofibrous mats were evaluated using high-performance liquid chromatography, showing a burst followed by sustained release over 24 h. To achieve longer sustained release, a poly(lactic-co-glycolic acid) coating was applied, resulting in extended release of up to 7 days. Biocompatibility assessment using human umbilical vein endothelial cells demonstrated successful attachment and viability of the nanofiber patches. Our study provides insights into the development of a drug delivery system for vascular grafts aimed at preventing infection during implantation, highlighting the potential of electrospinning as a promising technique in the field of vascular surgery.

Evaluation of lupeol-chitosan nanoparticles infused cellulose acetate membranes for enhanced in-vitro anticancer and antidiabetic activities

This study utilizes the abundance of pharmacologically active compounds found in natural products and concentrates on the promising anticancer agent lupeol (LUP). The limited water solubility and bioavailability of lupeol have limited its therapeutic utility. To test their potential for treating diabetes and cancer, we synthesized lupeol@chitosan (LUP@CS) nanoparticles encapsulated in cellulose acetate (CA) membranes (LUP@CS/CA). Extensive characterization, including Scanning electron microscopy, Thermogravimetric analysis, X-ray photoelectron spectroscopy, and mechanical strength analysis, confirmed the membrane's structural integrity and drug release capacity. Notably, in vitro experiments utilizing A431 human skin cancer cells revealed remarkable anticancer activity, positioning the membrane as a potential novel therapeutic agent for the treatment of skin cancer. Inhibiting carbohydrate-digesting enzymes effectively, as evidenced by IC50 values as low as 54.56 mg/mL, the membrane also exhibited significant antidiabetic potential. These results demonstrate the multifarious potential of the membrane, which offers promise for both the treatment of skin cancer and the management of diabetes, and has significant implications for nano biological applications.

Electrospinning technologies for the delivery of Biopharmaceuticals: Current status and future trends

This review provides an in-depth exploration of electrospinning techniques employed to produce micro- or nanofibres of biopharmaceuticals using polymeric solutions or melts with high-voltage electricity. Distinct from prior reviews, the current work narrows its focus on the recent developments and advanced applications in biopharmaceutical formulations. It begins with an overview of electrospinning principles, covering both solution and melt modes. Various methods for incorporating biopharmaceuticals into electrospun fibres, such as surface adsorption, blending, emulsion, co-axial, and high-throughput electrospinning, are elaborated. The review also surveys a wide array of biopharmaceuticals formulated through electrospinning, thereby identifying both opportunities and challenges in this emerging field. Moreover, it outlines the analytical techniques for characterizing electrospun fibres and discusses the legal and regulatory requirements for their production. This work aims to offer valuable insights into the evolving realm of electrospun biopharmaceutical delivery systems.

Berberine-loaded polylactic acid nanofiber scaffold as a drug delivery system: The relationship between chemical characteristics, drug-release behavior, and antibacterial efficiency

Hydrophobic berberine powder (BBR) and hydrophilic BBR nanoparticles (BBR NPs) were loaded into an electrospun polylactic acid (PLA) nanofiber scaffold for modulating the release behavior of BBR in an aqueous medium. The BBR release from the BBR/PLA and BBR NPs/PLA nanofiber scaffolds was investigated in relation to their chemical characteristics, BBR dispersion into nanofibers, and wettability. The BBR release profiles strongly influenced the antibacterial efficiency of the scaffolds over time. When the BBR was loaded, the BBR/PLA nanofiber scaffold exhibited an extremely hydrophobic feature, causing a triphasic release profile in which only 9.8 wt % of the loaded BBR was released in the first 24 h. This resulted in a negligible inhibitory effect against methicillin-resistant Staphylococcus aureus bacteria. Meanwhile, the BBR NPs/PLA nanofiber scaffold had more wettability and higher concentration of BBR NPs dispersed on the surface of PLA nanofibers. This led to a sustained release of 75 wt % of the loaded BBR during the first 24 h, and consequently boosted the antibacterial effectiveness. Moreover, the cytotoxicity test revealed that the BBR NPs/PLA nanofiber scaffold did not induce any changes in morphology and proliferation of MA-104 cell monolayers. It suggests that the BBR/PLA and BBR NPs/PLA nanofiber scaffolds can be used in different biomedical applications, such as wound dressing, drug delivery systems, and tissue engineering, according to the requirement of BBR concentration for the desired therapeutic effects.

Prolonged and Controllable Release of Doxorubicin Hydrochloride from the Composite Electrospun Poly(ε-Caprolactone)/Polyvinylpyrrolidone Scaffolds

Burst release, typical for the drug-loaded electrospun poly(ε-caprolactone) (PCL) scaffolds is unfavorable in case of cytostatics due to the toxic levels reached during the initial implantation period. In the present short communication, we report an unexpected ability of the composite scaffolds made of PCL and water-soluble polyvinylpyrrolidone (PVP) to provide long-term release of widely used anti-cancer drug doxorubicin hydrochloride (DOX-HCl). That effect was observed for electrospun DOX-HCl-loaded composite scaffolds based on PCL and PVP with various mass ratios (100/0, 95/5, 90/10, 75/25 and 50/50). After the morphology and water contact angle studies, it was concluded that PVP content has no effect on the average fiber diameter, while PVP content higher 10 wt. % changes the hydrophobic character of the scaffolds surface (water contact angle of 123.9 ± 3.5°) to superhydrophilic (water contact angle of 0°). Despite the dramatic change in water wettability, by high performance liquid chromatography (HPLC), it was revealed that the PVP content in the scaffolds reduces the DOX-HCl release rate under short (first hours) and long-term (during 1 month) exposure to phosphate buffer saline (PBS). These results are in good agreement with in vitro studies, in which the viability of HeLa cervical cancer cells was higher after 24 h of culture with scaffolds with high PVP content.

Modulating Drug Release from Short Poly(ethylene glycol) Block Initiated Poly(L-lactide) Di-block Copolymers

This paper investigates drug release from a novel series of mPEG-functionalised PLLA polymers whose individual components (PEG and PLLA) have regulatory FDA approval. Two processing methods were explored to understand their effect on the morphology and drug release profiles of the polymers, with and without mPEG functionalisation. In the first method the polymer and Propranolol.HCl drug powders were mixed together before injection moulding. In the second method, supercritical CO2 was used to mix the polymer and drug before injection moulding. When non-functionalised PLLA was processed through injection moulding alone, there were no signs of polymer-drug interaction, and the drug was confined to crystals on the surface. This resulted in up to 85 wt% burst release of propranolol.HCl after one day of incubation. By contrast, injection moulding of mPEG-functionalised polymers resulted in the partial dissolution of drug in the polymer matrix and a smaller burst (50 wt% drug) followed by sustained release. This initial burst release was completely eliminated from the profile of mPEG-functionalised polymers processed via supercritical CO2. The addition of mPEG facilitated the distribution of the drug into the bulk matrix of the polymer. Paired with supercritical CO2 processing, the drug release profile showed a slow, sustained release throughout the 4 months of the study.

The Reliability of PCL/Anti-VEGF Electrospun Scaffolds to Support Limbal Stem Cells for Corneal Repair

Since only few reported studies propose anti-vascular endothelial growth factor (anti-VEGF) delivery through electrospun scaffolds, this study greatly contributes to the potential prevention of patient's vision loss, as it explores electrospun polycaprolactone (PCL) coated with anti-VEGF for the blockage of abnormal cornea vascularization. In terms of physicochemical properties, the biological component increased the PCL scaffold fiber diameter (by ~24%) and pore area (by ~82%), while ut slightly reduced its total porosity as the anti-VEGF solution filled the voids of the microfibrous structure. The addition of the anti-VEGF increased the scaffold stiffness almost three-fold at both strains of 5 and 10%, as well as its biodegradation rate (~36% after 60 days) with a sustained release profile after Day 4 of phosphate buffered saline incubation. In terms of scaffold application function, the PCL/Anti-VEGF scaffold proved to be more favorable for the adhesion of cultured limbal stem cells (LSCs); this was confirmed by the SEM images, where the cells showed flat and elongated conformations. Further support of the LSC growth and proliferation was confirmed by the identified p63 and CK3 markers after cell staining. These results demonstrate the advantageous effect of the surface-adsorbed anti-VEGF to stop vision loss and help damaged corneal tissue repair.

Electrospun Drug-Loaded and Gene-Loaded Nanofibres: The Holy Grail of Glioblastoma Therapy?

To date, GBM remains highly resistant to therapies that have shown promising effects in other cancers. Therefore, the goal is to take down the shield that these tumours are using to protect themselves and proliferate unchecked, regardless of the advent of diverse therapies. To overcome the limitations of conventional therapy, the use of electrospun nanofibres encapsulated with either a drug or gene has been extensively researched. The aim of this intelligent biomaterial is to achieve a timely release of encapsulated therapy to exert the maximal therapeutic effect simultaneously eliminating dose-limiting toxicities and activating the innate immune response to prevent tumour recurrence. This review article is focused on the developing field of electrospinning and aims to describe the different types of electrospinning techniques in biomedical applications. Each technique describes how not all drugs or genes can be electrospun with any method; their physico-chemical properties, site of action, polymer characteristics and the desired drug or gene release rate determine the strategy used. Finally, we discuss the challenges and future perspectives associated with GBM therapy.

Investigation of the antitumor effect on breast cancer cells of the electrospun amygdalin-loaded poly(l-lactic acid)/poly(ethylene glycol) nanofibers

In this study, PLA/PEG nanofibers (NFs) loaded with amygdalin (AMG) and bitter almond kernels extract were produced by electrospinning to prevent local breast cancer recurrence, and the effect of produced NFs on the MCF-7 cell line was investigated in vitro. The electrospun NFs were characterized by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), thermal analysis (DSC) and tensile strength and physical analyzes were performed. Loading of AMG to nanofibers increased fiber diameters from 827.93 ± 174.507 nm to 1855.32 ± 291.057 μm. When drug release results were analyzed, the NFs showed a controlled release profile extending up to 10 h. The encapsulation efficiency of AMG-loaded NFs was calculated at 100 ± 0,01 %, 94 ± 0,02 %, and 88 ± 0,02 %. When in vitro cytotoxicity results were analyzed, showed that all NFs are effective in inducing cytotoxicity against MCF-7 breast cancer cells. Importantly, 20 mg AMG-loaded NFs displayed effectively higher cytotoxic effects against breast cancer cells relative to the other NFs. Considering all the results, AMG-loaded NFs can give sustained release of drugs at the local sites. Therefore, AMG-loaded nanofibers can reduce the risk of local recurrence of cancer after surgery and can be directly implanted into solid tumor cells for treatment.

Multilayered Polyurethane/Poly(vinyl alcohol) Nanofibrous Mats for Local Topotecan Delivery as a Potential Retinoblastoma Treatment

Local chemotherapy using polymer drug delivery systems has the potential to treat some cancers, including intraocular retinoblastoma, which is difficult to treat with systemically delivered drugs. Well-designed carriers can provide the required drug concentration at the target site over a prolonged time, reduce the overall drug dose needed, and suppress severe side effects. Herein, nanofibrous carriers of the anticancer agent topotecan (TPT) with a multilayered structure composed of a TPT-loaded inner layer of poly(vinyl alcohol) (PVA) and outer covering layers of polyurethane (PUR) are proposed. Scanning electron microscopy showed homogeneous incorporation of TPT into the PVA nanofibers. HPLC-FLD proved the good loading efficiency of TPT (≥85%) with a content of the pharmacologically active lactone TPT of more than 97%. In vitro release experiments demonstrated that the PUR cover layers effectively reduced the initial burst release of hydrophilic TPT. In a 3-round experiment with human retinoblastoma cells (Y-79), TPT showed prolonged release from the sandwich-structured nanofibers compared with that from a PVA monolayer, with significantly enhanced cytotoxic effects as a result of an increase in the PUR layer thickness. The presented PUR-PVA/TPT-PUR nanofibers appear to be promising carriers of active TPT lactone that could be useful for local cancer therapy.

Underestimated microbial infection of resorbable membranes on guided regeneration

Barrier membranes are critical in creating tissuecompartmentalization for guided tissue (GTR) and bone regeneration (GBR) therapies. More recently, resorbable membranes have been widely used for tissue and bone regeneration due to their improved properties and the dispensable re-entry surgery for membrane removal. However, in cases with membrane exposure, this may lead to microbial contamination that will compromise the integrity of the membrane, surrounding tissue, and bone regeneration, resulting in treatment failure. Although the microbial infection can negatively influence the clinical outcomes of regenerative therapy, such as GBR and GTR, there is a lack of clinical investigations in this field, especially concerning the microbial colonization of different types of membranes. Importantly, a deeper understanding of the mechanisms of biofilm growth and composition and pathogenesis on exposed membranes is still missing, explaining the mechanisms by which bone regeneration is reduced during membrane exposure. This scoping review comprehensively screened and discussed the current in vivo evidence and possible new perspectives on the microbial contamination of resorbable membranes. Results from eligible in vivo studies suggested that different bacterial species colonized exposed membranes according to their composition (collagen, expanded polytetrafluoroethylene (non-resorbable), and polylactic acid), but in all cases, it negatively affected the attachment level and amount of bone gain. However, limited models and techniques have evaluated the newly developed materials, and evidence is scarce. Finally, new approaches to enhance the antimicrobial effect should consider changing the membrane surface or incorporating long-term released antimicrobials in an effort to achieve better clinical success.

Electrospun fibers as carriers for topical drug delivery and release in skin bandages and patches for atopic dermatitis treatment

The skin is a complex layer system and the most important barrier between the environment and the organism. In this review, we describe some widespread skin problems, with a focus on eczema, which are affecting more and more people all over the world. Most of treatment methods for atopic dermatitis (AD) are focused on increasing skin moisture and protecting from bacterial infection and external irritation. Topical and transdermal treatments have specific requirements for drug delivery. Breathability, flexibility, good mechanical properties, biocompatibility, and efficacy are important for the patches used for skin. Up to today, electrospun fibers are mostly used for wound dressing. Their properties, however, meet the requirements for skin patches for the treatment of AD. Active agents can be incorporated into fibers by blending, coaxial or side-by-side electrospinning, and also by physical absorption post-processing. Drug release from the electrospun membranes is affected by drug and polymer properties and the technique used to combine them into the patch. We describe in detail the in vitro release mechanisms, parameters affecting the drug transport, and their kinetics, including theoretical approaches. In addition, we present the current research on skin patch design. This review summarizes the current extensive know-how on electrospun fibers as skin drug delivery systems, while underlining the advantages in their prospective use as patches for atopic dermatitis. This article is categorized under: Implantable Materials and Surgical Technologies > Nanomaterials and Implants Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Electrospun nanofibers for 3-D cancer models, diagnostics, and therapy

As one of the leading causes of global mortality, cancer has prompted extensive research and development to advance efficacious drug discovery, sustained drug delivery and improved sensitivity in diagnosis. Towards these applications, nanofibers synthesized by electrospinning have exhibited great clinical potential as a biomimetic tumor microenvironment model for drug screening, a controllable platform for localized, prolonged drug release for cancer therapy, and a highly sensitive cancer diagnostic tool for capture and isolation of circulating tumor cells in the bloodstream and for detection of cancer-associated biomarkers. This review provides an overview of applied nanofiber design with focus on versatile electrospinning fabrication techniques. The influence of topographical, physical, and biochemical properties on the function of nanofiber assemblies is discussed, as well as current and foreseeable barriers to the clinical translation of applied nanofibers in the field of oncology.

Preparation and Characterization of Simvastatin-Loaded PCL/PEG Nanofiber Membranes for Drug Sustained Release

Simvastatin (SIM) particles are liposoluble drugs with large particle sizes, resulting in poor compatibility with electrospun polycaprolactone (PCL)/polyethylene glycol (PEG) nanofibers, so that part of them will be exposed to the electrospun nanofiber surface, which is easy to cause the burst release of drugs. Therefore, in this paper, stearic acid (SA) with good biocompatibility was innovatively added to increase the dispersion uniformity of SIM in the spinning solution, thus improving the performances of SIM-loaded PCL/PEG nanofiber membranes (NFMs). Accordingly, the effects of SA addition on the morphologies, mechanical properties, wettability, and drug release properties of the SIM-loaded NFMs were studied. The results showed that after SIM was dissolved in SA solution, the particle size of SIM was significantly reduced and could be evenly dispersed in the polymer spinning solution, thus obtaining the SIM-loaded composite NFMs with the best morphology and performance.

Controlled drug delivery and cell adhesion for bone tissue regeneration by Keplerate polyoxometalate (Mo132)/metronidazole/PMMA scaffolds

The aim of this study is to fabricate a new scaffold appropriate for tissue regeneration with antimicrobial activity and ability of controlled drug delivery. In this regard, scaffold nanofibers were produced using poly (methyl methacrylate) (PMMA), Mo₁₃₂ as a Keplerate polyoxometalate and metronidazole. The final scaffolds, obtained by electrospinning, represent the intrinsic features including exceptional doubling tensile strength, high hydrophilicity (126 ± 5.2° to 83.9 ± 3.2° for contact angle and 14.18 ± 0.62% to 35.62 ± 0.24% for water uptake), proper bioactivity and cell adhesion. Moreover, the addition of Mo₁₃₂ and metronidazole enhances the biodegradation rate of resulted scaffolds compared to the pure PMMA membrane. The controlled release of metronidazole over 14 days efficiently inhibits the colonization of anaerobic microorganisms. Overall, the results demonstrate high potential of Mo₁₃₂ and metronidazole-loaded PMMA scaffold for guided bone regeneration/guided tissue regeneration.

Electrospun Membranes Designed for Burst Release of New Gold-Complexes Inducing Apoptosis of Melanoma Cells

Two non-commercial metallic Au-based complexes were tested against one of the most aggressive malignant melanomas of the skin (MeWo cells), through cell viability and time-lapse live-cell imaging system assays. The tests with the complexes were carried out both in the form of free metallic complexes, directly in contact with the MeWo cell line culture, and embedded in fibers of Polycaprolactone (PCL) membranes produced by the electrospinning technique. Membranes functionalized with complexes were prepared to evaluate the efficiency of the membranes against the melanoma cells and therefore their feasibility in the application as an antitumoral patch for topical use. Both series of tests highlighted a very effective antitumoral activity, manifesting a very relevant cell viability inhibition after both 24 h and 48 h. In the case of the AuM1 complex at the concentration of 20 mM, melanoma cells completely died in this short period of time. A mortality of around 70% was detected from the tests performed using the membranes functionalized with AuM1 complex at a very low concentration (3 wt.%), even after 24 h of the contact period. The synthesized complexes also manifest high selectivity with respect to the MeWo cells. The peculiar structural and morphological organization of the nanofibers constituting the membranes allows for a very effective antitumoral activity in the first 3 h of treatment. Experimental points of the release profiles were perfectly fitted with theoretical curves, which easily allow interpretation of the kinetic phenomena occurring in the release of the synthesized complexes in the chosen medium.

Control of drug release from cotton fabric by nanofibrous mat

A drug delivery system (DDSs) was developed in the present study based on textile substrates as drug carriers and electrospun nanofibers as a controller of release rate. Three types of drugs consisting of ciprofloxacin (CIP), clotrimazole (CLO), and benzalkonium chloride (BEN) were loaded into the cover glass (CG) and cotton fabrics (CF1 and CF2) separately. Then, the drug-loaded substrates were coated with polycaprolactone (PCL) and polycaprolactone/gelatin (PCL/Gel) nanofibers with various thicknesses. The morphology and hydrophilicity of the electrospun nanofibers and the release profile of drug-loaded samples were investigated. FTIR, XRD, and in vitro biodegradability analysis were analyzed to characterize the drug delivery system. A morphological study of electrospun fibers showed the mean diameter of the PCL and PCL/Gel nanofibers 127 ± 25 and 178 ± 38 nm, respectively. The drug delivery assay revealed that various factors affect the rate of drug releases, such as the type of drug, the type of drug carrier, and the thickness of the covered nanofibers. The study highlights the ability of drugs to load substrates with coated nanofibers as controlled drug delivery systems. In conclusion, it is shown that the obtained samples are excellent candidates for future wound dressing applications.

Drug delivery across the blood-brain barrier for the treatment of pediatric brain tumors - An update

Even though the last decade has seen a surge in the identification of molecular targets and targeted therapies in pediatric brain tumors, the blood brain barrier (BBB) remains a significant challenge in systemic drug delivery. This continues to undermine therapeutic efficacy. Recent efforts have identified several strategies that can facilitate enhanced drug delivery into pediatric brain tumors. These include invasive methods such as intra-arterial, intrathecal, and convection enhanced delivery and non-invasive technologies that allow for transient access across the BBB, including focused ultrasound and nanotechnology. This review discusses current strategies that are being used to enhance delivery of different therapies across the BBB to the tumor site - a major unmet need in pediatric neuro-oncology.

Metformin-Loaded Polymer-Based Microbubbles/Nanoparticles Generated for the Treatment of Type 2 Diabetes Mellitus

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease that is increasingly common all over the world with a high risk of progressive hyperglycemia and high microvascular and macrovascular complications. The currently used drugs in the treatment of T2DM have insufficient glucose control and can carry detrimental side effects. Several drug delivery systems have been investigated to decrease the side effects and frequency of dosage, and also to increase the effect of oral antidiabetic drugs. In recent years, the use of microbubbles in biomedical applications has greatly increased, and research into microactive carrier bubbles continues to generate more and more clinical interest. In this study, various monodisperse polymer nanoparticles at different concentrations were produced by bursting microbubbles generated using a T-junction microfluidic device. Morphological analysis by scanning electron microscopy, molecular interactions between the components by FTIR, drug release by UV spectroscopy, and physical analysis such as surface tension and viscosity measurement were carried out for the particles generated and solutions used. The microbubbles and nanoparticles had a smooth outer surface. When the microbubbles/nanoparticles were compared, it was observed that they were optimized with 0.3 wt % poly(vinyl alcohol) (PVA) solution, 40 kPa pressure, and a 110 μL/min flow rate, thus the diameters of the bubbles and particles were 100 ± 10 μm and 70 ± 5 nm, respectively. Metformin was successfully loaded into the nanoparticles in these optimized concentrations and characteristics, and no drug crystals and clusters were seen on the surface. Metformin was released in a controlled manner at pH 1.2 for 60 min and at pH 7.4 for 240 min. The process and structures generated offer great potential for the treatment of T2DM.

Non-Woven Sheet Containing Gemcitabine: Controlled Release Complex for Pancreatic Cancer Treatment

The 5-year survival rate for pancreatic cancer remains low, and the development of new methods for its treatment is actively underway. After the surgical treatment of pancreatic cancer, recurrence and peritoneal dissemination can be prevented by long-term local exposure to appropriate drug concentrations. We propose a novel treatment method using non-woven sheets to achieve this goal. Poly(L-lactic acid) non-woven sheets containing gemcitabine (GEM) were prepared, and GEM sustained release from this delivery system was investigated. Approximately 35% of the GEM dose was released within 30 d. For in vitro evaluation, we conducted a cell growth inhibition test using transwell assays, and significant inhibition of cell growth was observed. The antitumor effects of subcutaneously implanted GEM-containing non-woven sheets were evaluated in mice bearing subcutaneous Panc02 cells, and it was established that the sheets inhibited tumor growth for approximately 28 d. These results suggest the usefulness of GEM-containing non-woven sheets in pancreatic cancer treatment.

Design of Biopolymer-Based Interstitial Therapies for the Treatment of Glioblastoma

Glioblastoma multiforme (GBM) is the most common form of primary brain cancer and has the highest morbidity rate and current treatments result in a bleak 5-year survival rate of 5.6%. Interstitial therapy is one option to increase survival. Drug delivery by interstitial therapy most commonly makes use of a polymer implant encapsulating a drug which releases as the polymer degrades. Interstitial therapy has been extensively studied as a treatment option for GBM as it provides several advantages over systemic administration of chemotherapeutics. Primarily, it can be applied behind the blood–brain barrier, increasing the number of possible chemotherapeutic candidates that can be used and reducing systemic levels of the therapy while concentrating it near the cancer source. With interstitial therapy, multiple drugs can be released locally into the brain at the site of resection as the polymer of the implant degrades, and the release profile of these drugs can be tailored to optimize combination therapy or maintain synergistic ratios. This can bypass the blood–brain barrier, alleviate systemic toxicity, and resolve drug resistance in the tumor. However, tailoring drug release requires appropriate consideration of the complex relationship between the drug, polymer, and formulation method. Drug physicochemical properties can result in intermolecular bonding with the polymeric matrix and affect drug distribution in the implant depending on the formulation method used. This review is focused on current works that have applied interstitial therapy towards GBM, discusses polymer and formulation methods, and provides design considerations for future implantable biodegradable materials.

5FU-loaded PCL/Chitosan/Fe3O4 Core-Shell Nanofibers Structure: An Approach to Multi-Mode Anticancer System

Purpose: 5FU and Fe3O4 nanoparticles were encapsulated in core-shell Polycaprolactone/Chitosan nanofibers as a multi-mode anticancer system to study drug release sustainability. The structure of the core-shell drug delivery system was also optimized according to drug release behavior by artificial intelligence. Methods: The core-shell nanofibers were electrospun by a coaxial syringe. ANN was used for function approximation to estimate release parameters. A genetic algorithm was then used for optimizing the structure. Chemical assay of the optimized sample was performed by FTIR, XRD, and EDX. VSM test was conducted to measure the real amount of loaded magnetic nanoparticles. HepG2 cell cytotoxicity was studied and the results for the optimized samples with and without Fe3O4 after 72hrs were reported. Results: Feeding ratio of sheath to core and the amount of CS, Fe3O4, and 5FU had a statistical effect on nanofibers diameters, which were 300-450nm. The drug loading efficiency of these nanofibers was 65-86%. ANN estimated the release parameters with an error of 10%. The temperature increased about 5.6°C in the AMF of 216kA.m-1~300kHz and 4.8°C in the AMF of 154kA.m-1~400kHz after 20min. HepG2 cell cytotoxicity for the optimized samples with and without Fe3O4 after 72hrs were 39.7% and 38.8%, respectively. Conclusion: Since this core-shell drug release system was more sustainable compared to the blend structure despite the low half-life of 5FU, it is suggested to utilize it as post-surgical implants for various cancer treatments such as liver or colorectal cancer in the future. This system is capable of providing chemotherapy and hyperthermia simultaneously.

A simvastatin-releasing scaffold with periodontal ligament stem cell sheets for periodontal regeneration

Simvastatin (SIM) has been documented to induce the osteogenic differentiation of periodontal ligament stem cells (PDLSCs). To establish an efficient release system for periodontal regeneration, a polycaprolactone (PCL) membrane scaffold containing SIM was electrospun and evaluated. The obtained PCL-SIM membrane scaffold showed sustained release up to 28 days, without deleterious effect on proliferation of PDLSCs on the scaffolds. PDLSCs were seeded onto scaffolds and their osteogenic differentiation was evaluated. After 21 days, expressions of collagen type I, alkaline phosphatase and bone sialoprotein genes were significantly upregulated and mineralized matrix formation was increased on the PCL-SIM scaffolds compared with the PCL scaffolds. In a heterotopic periodontal regeneration model, a cell sheet-scaffold construct was assembled by placement of multilayers of PDLSC sheets on PCL or PCL-SIM scaffolds, and these were then placed between dentin and ceramic bovine bone for subcutaneous implantation in athymic mice. After 8 weeks, the PCL-SIM membrane showed formation of significantly more ectopic cementum-like mineral on the dentin surface. These findings demonstrated that the PCL-SIM membrane scaffold promotes cementum-like tissue formation by sustained drug release, suggesting the feasibility of its therapeutic use with PDLSC sheets to improve periodontal regeneration.

Removal of trace DNA toxic compounds using a Poly(deep eutectic solvent)@Biomass based on multi-physical interactions

DNA toxic compounds (DNA-T-Cs), even in trace amounts, seriously threaten human health and must be completely eliminated. However, the currently used separation media face great challenges in removing trace DNA-T-Cs. Based on the functional advantages of deep eutectic solvents (DESs) and the natural features of biomass (BioM), a series of Poly(DES)@BioMs functioning as adsorbents were prepared for the removal of aromatic/hetero-atomic DNA-T-Cs at the ppm level. After optimisation of experimental conditions, the removal efficiency for DNA-T-Cs ranged from 92.4% to 96.0% with an initial concentration of 20.0 ppm, a temperature of 30 °C, duration of 30 min, and pH of 7.0. The removal processes between the DNA-T-Cs and Poly(DES)@BioMs are well described in the Temkin equilibrium and second-order kinetic adsorption models, and the desorption processes are well shown in the Korsmeryer-Peppas equilibrium and zero-order kinetic models. Molecular simulations revealed that the removal interactions include hydrogen bonding, π-π stacking, and hydrophobic/hydrophilic effects. The removal efficiency for the DNA-T-Cs at 8.0 ppm in industrial sewage ranged from 69.7% to 102%, while the removal efficiency for the DNA-T-Cs standing alone at 20.0 ppm in a methyl violet drug solution was 95.4%, confirming that the Poly(DES)@BioMs effectively removed trace DNA-T-Cs in field samples.

Preparation and characterization of silk fibroin/polyethylene oxide nanofiber membranes with antibacterial activity

Bacterial infection is among the most common diseases that threaten human health. Antibiotics are effective in treating bacterial infections. However, the overuse of antibiotics will lead to an increase in bacterial resistance. To reduce the overuse of antibiotics and improve the effective use of antibiotics through slow release, silk fibroin (SF)/polyethylene oxide (PEO) nanofiber membranes with different SF and PEO proportions were prepared by electrospinning. The ecofriendly solvent ethanol solution was used for electrospinning for better protection of antibiotic activity. The SEM showed that the surface of SF/PEO (2:8) and SF/PEO (3:7) was smoother and more uniform. With the increase of SF content, the thermal stability and hydrophilicity of SF/PEO nanofiber membranes were improved. The SF/PEO (3:7) nanofiber membrane had the best mechanical property and its maximum stress and strain were 4.6 1 ± 0.24 MPa and 16.36 ± 0.41%, respectively. Based on these good properties, SF/PEO (3:7) nanofiber membrane was chosen for loading and releasing gentamicin sulfate (GS). The fabricated (GS)/SF/PEO (3:7) nanofiber membrane exhibited good release efficiency and showed the good antibacterial activity against Staphylococcus aureus and Escherichia coli. These investigations indicated the GS/SF/PEO (3:7) nanofiber membrane (GS/SF/PEO) has a great potential for application in antibacterial materials.

Electrospun Nanofibers of Polycaprolactone/Collagen as a Sustained-Release Drug Delivery System for Artemisinin

The application of artemisinin (ART) in the treatment of malaria has been restricted to a certain degree due to its inherent limitations, such as short half-life, poor solubility, limited bioavailability, and re-crystallization. Electrospun nanofibers loaded with ART provide an excellent solution to these limitations and yield sustained drug release as well as inhibition of drug re-crystallization. In this study, ART-loaded polycaprolactone (PCL)/collagen (Col) nanofibers with different proportions of polymers were prepared. ART-loaded PCL/Col nanofibers were characterized, and further ART anti-crystallization and release behaviors were studied. SEM was used to observe the morphology of PCL/Col nanofibers. X-ray diffraction (XRD) was used to characterize the physical state of ART in ART-loaded PCL/Col nanofibers. Fourier transform infrared spectroscopy (FTIR), water contact angle measurement, weight loss, degree of swelling, and drug release experiments can verify the differences in performance of ART-loaded PCL/Col nanofibers due to different polymer ratios. The release curve was analyzed by kinetics, showing sustained release for up to 48 h, and followed the Fickian release mechanism, which was shown by the diffusion index value obtained from the Korsmeyer-Peppas equation.

Application of Electrospinning in Antibacterial Field

In recent years, electrospun nanofibers have attracted extensive attention due to their large specific surface area, high porosity, and controllable shape. Among the many applications of electrospinning, electrospun nanofibers used in fields such as tissue engineering, food packaging, and air purification often require some antibacterial properties. This paper expounds the development potential of electrospinning in the antibacterial field from four aspects: fiber morphology, antibacterial materials, antibacterial mechanism, and application fields. The effects of fiber morphology and antibacterial materials on the antibacterial activity and characteristics are first presented, then followed by a discussion of the antibacterial mechanisms and influencing factors of these materials. Typical application examples of antibacterial nanofibers are presented, which show the good prospects of electrospinning in the antibacterial field.

Development and Evaluation of a Human Skin Equivalent in a Semiautomatic Microfluidic Diffusion Chamber

There is an increasing demand for transdermal transport measurements to optimize topical drug formulations and to achieve proper penetration profile of cosmetic ingredients. Reflecting ethical concerns the use of both human and animal tissues is becoming more restricted. Therefore, the focus of dermal research is shifting towards in vitro assays. In the current proof-of-concept study a three-layer skin equivalent using human HaCaT keratinocytes, an electrospun polycaprolactone mesh and a collagen-I gel was compared to human excised skin samples. We measured the permeability of the samples for 2% caffeine cream using a miniaturized dynamic diffusion cell (“skin-on-a-chip” microfluidic device). Caffeine delivery exhibits similar transport kinetics through the artificial skin and the human tissue: after a rapid rise, a long-lasting high concentration steady state develops. This is markedly distinct from the kinetics measured when using cell-free constructs, where a shorter release was observable. These results imply that both the established skin equivalent and the microfluidic diffusion chamber can serve as a suitable base for further development of more complex tissue substitutes.

Electrospinning for drug delivery applications: A review

Drug delivery devices are promising tools in the pharmaceutical field, as they are able to maximize the therapeutic effects of the delivered drug while minimizing the undesired side effects. In the past years, electrospun nanofibers attracted rising attention due to their unique features, like biocompatibility and broad flexibility. Incorporation of active principles in nanofibrous meshes proved to be an efficient method for in situ delivery of a wide range of drugs, expanding the possibility and applicability of those devices. In this review, the principle of electrospinning and different fields of applications are treated to give an overview of the recent literature, underlining the easy tuning and endless combination of this technique, that in the future could be the new frontier of personalized medicine.

Novel electrospun poly-hydroxybutyrate scaffolds as carriers for the wound healing agents alkannins and shikonins

The aim of this study was to investigate the potential of novel electrospun fiber mats loaded with alkannin and shikonin (A/S) derivatives, using as carrier a highly biocompatible, bio-derived, eco-friendly polymer such as poly[(R)-3-hydroxybutyric acid] (PHB). PHB fibers containing a mixture of A/S derivatives at different ratios were successfully fabricated via electrospinning. Αs evidenced by scanning electron microscopy, the fibers formed a bead-free mesh with average diameters from 1.25 to 1.47 μm. Spectroscopic measurements suggest that electrospinning marginally increases the amorphous content of the predominantly crystalline PHB in the fibers, while a significant drug amount lies near the fiber surface for samples of high total A/S content. All scaffolds displayed satisfactory characteristics, with the lower concentrations of A/S mixture-loaded PHB fiber mats achieving higher porosity, water uptake ratios, and entrapment efficiencies. The in vitro dissolution studies revealed that all samples released more than 70% of the encapsulated drug after 72 h. All PHB scaffolds tested by cell viability assay were proven non-toxic for Hs27 fibroblasts, with the 0.15 wt.% sample favoring cell attachment, spreading onto the scaffold surface, as well as cell proliferation. Finally, the antimicrobial activity of PHB meshes loaded with A/S mixture was documented for Staphylococcus epidermidis and S. aureus.