Novel controlled drug delivery system for multiple drugs based on electrospun nanofibers containing nanomicelles

Improved antitumor activity through a tyramidyl maslinic acid derivative. Design and validation as drug-loaded electrospun polymeric nanofibers

Among the most harmful tumors detected in the human body, such as breast, colon, brain or pancreas, breast (BC) and colorectal cancer (CRC) are the first and third most frequent cancer worldwide, respectively. The current existing chemotherapeutic treatments present serious side effects due to their intravenous administration can induce cytotoxicity in healthy cells. Thus, new treatment methods based on drug-loaded polymeric nanofibers (NFs) have gained significant potential for their use in localized cancer chemotherapy. Here, a deep in vitro comparative analysis between maslinic acid (MA) and a tyramine-maslinic acid (TMA) derivative is initially performed. This analysis includes a proliferation, and a cell cycle assay, and a genotoxicity, antiangiogenic and apoptosis study. Then, the TMA derivative has been incorporated into electrospun polymeric NFs obtaining an implantable dressing material with antitumor activity. Two types of patches containing TMA-loaded polymeric NFs of poly(caprolactone) (PCL), and a mixture of polylactic acid/poly(4-vinylpyridine) (PLA/PVP) were fabricated by the electrospinning technique. The characterization of the drug-loaded NFs showed an encapsulation capacity of 0.027 mg TMA/mg PCL and 0.024 mg TMA/mg PLA/PVP. Then, the cytotoxic activity of both polymeric systems was tested in CRC (T84), BC (MCF-7) and a no tumor (L929) cell lines exposed to TMA-loaded NFs and blank NFs for 48 h. Moreover, cell cycle assay, genotoxicity, angiogenesis and apoptosis tests were carried out to study the mechanism of action of TMA. Blank NFs showed no-toxicity in all cell lines tested and both drug-loaded NFs significantly reduced cell proliferation (relative proliferation of ≈44 % and ≈25 % respectively). Therefore, TMA was less genotoxic than maslinic acid (MA), and reduced VEGFA expression in MCF-7 cells (1.32 and 2.12-fold for MA and TMA respectively). These results showed that TMA-loaded NFs could constitute a promising biocompatible and biodegradable nanoplatform for the local treatment of solid tumors such as CRC or BC.

An overview on electrospinning and its advancement toward hard and soft tissue engineering applications

One of the emerging technologies of the recent times harboring nanotechnology to fabricate nanofibers for various biomedical and environmental applications are electrospinning (nanofiber technology). Their relative ease in use, simplicity, functionality and diversity has surpassed the pitfalls encountered with the conventional method of generating fibers. This review aims to provide an overview of electrospinning, principle, methods, feed materials, and applications toward tissue engineering. To begin with, evolution of electrospinning and its typical apparatus have been briefed. Simultaneously, discussion on the production of nanofibers with diversified feed materials such as polymers, small molecules, colloids, and nanoparticles and its transformation into a powerful technology has been dealt with. Further, highlights on the application of nanofibers in tissue engineering and the commercialized products developed using nanofiber technology have been summed up. With this rapidly emerging technology, there would be a great demand pertaining to scalability and environmental challenge toward tissue engineering applications.

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.

Cephradine drug release using electrospun chitosan nanofibers incorporated with halloysite nanoclay

The chitosan/polyvinyl alcohol/halloysite nanoclay (CS/PVA/HNC) loaded with cephradine drug electrospun nanofibers (NFs) were fabricated and characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) techniques. FTIR analysis confirmed the hydrogen bonding between the polymer chain and the developed siloxane linkages. SEM analysis revealed the formation of uniform NFs having beads free and smooth surface with an average diameter in 50–200 nm range. The thermal stability of the NFs was increased by increasing the HNC concentration. The antimicrobial activity was examined against Escherichia  coli and staphylococcus strains and the NFs revealed auspicious antimicrobial potential. The drug release was studied at pH 7.4 (in PBS) at 37 °C. The drug release analysis showed that 90% of the drug was released from NFs in 2 h and 40 min. Hence, the prepared NFs could be used as a potential drug carrier and release in a control manner for biomedical application.

Thermosensitive Interfacial Migration of 5-FU in the Microenvironment of Pluronic Block Copolymers

Chemotherapy is one of the most important ways to treat cancer. At present, chemotherapy medicines are mainly administered by intravenous injection or oral administration. However, systemic medical care requires the dosage of high concentrations of drugs to defeat the malignant tumor growth. In recent years, the use of polymer composites for local and sustained drug release has become an important field of research to minimize side effects due to high-concentration chemotherapy drugs. Here, ¹⁹F-{¹H} heteronuclear Overhauser enhancement spectroscopy (HOESY) was used to study the micellular environment of the F-containing chemotherapeutic drug 5-FU in Pluronic F127, Pluronic L121, and F127/L121 binary blending composites. The distribution of 5-FU in micelles is related to the PEO and PPO segment length of Pluronic polymers and the environmental temperature. The drug release tests further confirm that if 5-FU medicines were loaded in the PPO segment inside the micelles, the purpose of the prolonged drug release carrier is achieved.

Electrospun Fibres of Chitosan/PVP for the Effective Chemotherapeutic Drug Delivery of 5-Fluorouracil

Electrospun nanofibrous mats consisting of chitosan (CS) and polyvinylpyrrolidone (PVP) were constructed. Tuning of solution and process parameters was performed and resulted in an electrospun system containing a 6:4 ratio of PVP:CS. This is a significant increase in the proportion of spun CS on the previously reported highest ratio PVP:CS blend. SEM analysis showed that the nanofibrous mats with 4 wt% CS/6 wt% PVP (sample E) comprised homogenous, uniform fibres with an average diameter of 0.569 μm. XPS analysis showed that the surface of the samples consisted of PVP. Raman and FTIR analysis revealed intermolecular interactions (via H-bonding) between PVP and CS. In FTIR spectra, the contribution of chitosan to CS/PVP complexes was shown by the downshift of the C=O band and by the linear increase in intensity of C-O stretching in CS. XPS analysis showed a smaller shift at the binding energy 531 eV, which relates to the amide of the acetylated functional groups. The obtained results demonstrate a sensitivity of Raman and FTIR tests to the presence of chitosan in PVP:CS blend. The chemotherapy drug 5-Fu was incorporated into the constructs and cell viability studies were performed. WST-8 viability assay showed that exposure of A549 human alveolar basal epithelial cells to 10 mg/mL 5-Fu loaded fibres was most effective at killing cells over 24 h. On the other hand, the constructs with loading of 1 mg/mL of drug were not efficient at killing A549 human alveolar basal epithelial cells. This study showed that CS/PVP/5-Fu constructs have potential in chemotherapeutic drug delivery systems.

Multidrug-loaded electrospun micro/nanofibrous membranes: Fabrication strategies, release behaviors and applications in regenerative medicine

Electrospun micro/nanofibrous membranes (EFMs) have been widely investigated as local drug delivery systems. Multiple drugs can be simultaneously incorporated into one EFM to create synergistic effects, reduce side effects, and play their respective roles in the complex physiological processes of tissue regeneration and postoperative adhesion prevention. Due to the versatile electrospinning techniques, sustained and programmed release behaviors of multiple drugs could be achieved by modulating the structure of the EFMs and the location of the drugs. In this review, various multidrug incorporation approaches based on electrospinning are overviewed. In particular, the advantages and limitations of each drug incorporation technique, the methods to control drug release and the effect of one drug release on another are discussed. Then the applications of multidrug-loaded EFMs in regenerative medicine, including wound healing, bone regeneration, vascular tissue engineering, nerve regeneration, periodontal regeneration and adhesion prevention are comprehensively reviewed. Finally, the future perspectives and challenges in the research of multidrug-loaded EFMs are discussed.

In vivo Serum Enabled Production of Ultrafine Nanotherapeutics for Cancer Treatment

Systemic delivery of hydrophobic anti-cancer drugs with nanocarriers, particularly for drug-resistant and metastatic cancer, remain a challenge because of the difficulty to achieve high drug loading, while maintaining a small hydrodynamic size and colloid stability in blood to ensure delivery of an efficacious amount of drug to tumor cells. Here we introduce a new approach to address this challenge. In this approach, nanofibers of larger size with good drug loading capacity are first constructed by a self-assembly process, and upon intravascular injection and interacting with serum proteins in vivo, these nanofibers break down into ultra-fine nanoparticles of smaller size that inherit the drug loading property from their parent nanofibers. We demonstrate the efficacy of this approach with a clinically available anti-cancer drug: paclitaxel (PTX). In vitro, the PTX-loaded nanoparticles enter cancer cells and induce cellular apoptosis. In vivo, they demonstrate prolonged circulation in blood, induce no systemic toxicity, and show high potency in inhibiting tumor growth and metastasis in both mouse models of aggressive, drug-resistant breast cancer and melanoma. This study points to a new strategy toward improved anti-cancer drug delivery and therapy.

Nobiletin-loaded micelles reduce ovariectomy-induced bone loss by suppressing osteoclastogenesis

Background

Nobiletin (NOB), a polymethoxy flavonoid, possesses anti-cancer and anti-inflammatory activities, has been reported that it played role in anti-osteoporosis treatment. However, previous research did not focus on practical use due to lack of hydrophilicity and cytotoxicity at high concentrations. The aim of this study was to develop a therapeutic formulation for osteoporosis based on the utilization of NOB.

Methods

In this study, NOB-loaded poly(ethylene glycol)-block-poly(e-caprolactone) (NOB-PEG-PCL) was prepared by dialysis method. The effects on osteoclasts and anti-osteoporosis functions were investigated in a RANKL-induced cell model and ovariectomized (OVX) mice.

Results

Dynamic light scattering and transmission electron microscopy examination results revealed that the NOB-PEG-PCL had a round shape, with a mean diameter around 124 nm. The encapsulation efficiency and drug loading were 76.34±3.25% and 7.60±0.48%, respectively. The in vitro release of NOB from NOB-PEG-PCL showed a remarkably sustained releasing characteristic and could be retained at least 48 hrs in pH 7.4 PBS. Anti-osteoclasts effects demonstrated that the NOB-PEG-PCL significantly inhibited the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cells stimulated by RANKL. Furthermore, the NOB-PEG-PCL did not produce cytotoxicity on bone marrow-derived macrophages (BMMs). The mRNA expressions of genetic markers of osteoclasts including TRAP and cathepsin K were significantly decreased in the presence of NOB-PEG-PCL. In addition, the NOB-PEG-PCL inhibited OC differentiation of BMMs through RANKL-induced MAPK signal pathway. After administration of the NOB-PEG-PCL, NOB-PEG-PCL prevented bone loss and improved bone density in OVX mice. These findings suggest that NOB-PEG-PCL might have great potential in the treatment of osteoporosis.

Conclusion

The results suggested that NOB-PEG-PCL micelles could effectively prevent NOB fast release from micelles and extend circulation time. The NOB-PEG-PCL delivery system may be a promising way to prevent and treat osteoporosis.

Electrospun Nanofibers: Recent Applications in Drug Delivery and Cancer Therapy

Polymeric nanofibers (NFs) have been extensively reported as a biocompatible scaffold to be specifically applied in several researching fields, including biomedical applications. The principal researching lines cover the encapsulation of antitumor drugs for controlled drug delivery applications, scaffolds structures for tissue engineering and regenerative medicine, as well as magnetic or plasmonic hyperthermia to be applied in the reduction of cancer tumors. This makes NFs useful as therapeutic implantable patches or mats to be implemented in numerous biomedical researching fields. In this context, several biocompatible polymers with excellent biocompatibility and biodegradability including poly lactic-co-glycolic acid (PLGA), poly butylcyanoacrylate (PBCA), poly ethylenglycol (PEG), poly (ε-caprolactone) (PCL) or poly lactic acid (PLA) have been widely used for the synthesis of NFs using the electrospun technique. Indeed, other types of polymers with stimuli-responsive capabilities has have recently reported for the fabrication of polymeric NFs scaffolds with relevant biomedical applications. Importantly, colloidal nanoparticles used as nanocarriers and non-biodegradable structures have been also incorporated by electrospinning into polymeric NFs for drug delivery applications and cancer treatments. In this review, we focus on the incorporation of drugs into polymeric NFs for drug delivery and cancer treatment applications. However, the principal novelty compared with previously reported publications is that we also focus on recent investigations concerning new strategies that increase drug delivery and cancer treatments efficiencies, such as the incorporation of colloidal nanoparticles into polymeric NFs, the possibility to fabricate NFs with the capability to respond to external environments, and finally, the synthesis of hybrid polymeric NFs containing carbon nanotubes, magnetic and gold nanoparticles, with magnetic and plasmonic hyperthermia applicability.

Relating Advanced Electrospun Fiber Architectures to the Temporal Release of Active Agents to Meet the Needs of Next-Generation Intravaginal Delivery Applications

Electrospun fibers have emerged as a relatively new delivery platform to improve active agent retention and delivery for intravaginal applications. While uniaxial fibers have been explored in a variety of applications including intravaginal delivery, the consideration of more advanced fiber architectures may offer new options to improve delivery to the female reproductive tract. In this review, we summarize the advancements of electrospun coaxial, multilayered, and nanoparticle-fiber architectures utilized in other applications and discuss how different material combinations within these architectures provide varied durations of release, here categorized as either transient (within 24 h), short-term (24 h to one week), or sustained (beyond one week). We seek to systematically relate material type and fiber architecture to active agent release kinetics. Last, we explore how lessons derived from these architectures may be applied to address the needs of future intravaginal delivery platforms for a given prophylactic or therapeutic application. The overall goal of this review is to provide a summary of different fiber architectures that have been useful for active agent delivery and to provide guidelines for the development of new formulations that exhibit release kinetics relevant to the time frames and the diversity of active agents needed in next-generation multipurpose applications.

Dual micelles-loaded gelatin nanofibers and their application in lipopolysaccharide-induced periodontal disease

INTRODUCTION

Combined therapies utilizing inhibitors to remove pathogens are needed to suppress lipopolysaccharide (LPS)-induced periodontal disease. We prepared a novel, multi-agent delivery scaffold for periodontal treatment.

METHODS

In this study, we synthesized SP600125 (a JNK inhibitor) and SB203580 (a p38 inhibitor) drug-loaded poly(ethylene glycol)-block-caprolactone copolymer via dialysis method. The physical property of micelles was characterized through dynamic light scattering and transmission electron microscopy. The cell growth and LPS-induced MMP-2 and MMP-13 expression were evaluated through CCK-8, real-time PCR and Western blot assay. The release of SP600125 and SB203580 from different scaffolds was estimated. Microcomputed tomography and histology were used for evaluating the effect of the micelles-loaded nanofibers on the treatment of class II furcation defects in dogs.

RESULTS

The drug was then successfully incorporated into gelatin fibers during electrospinning process. We confirmed that the micelles had spherical structure and an average particle size of 160 nm for SP600125-micelles (SP-Ms) and 150 nm for SB203580-micelles (SB-Ms). The nanofiber scaffold showed excellent encapsulation capability, in vitro drug-release behavior, and cell compatibility. Real-time PCR and Western blot assay further indicated that LPS-induced MMP-2 and MMP-13 expression was significantly inhibited by the scaffold.

CONCLUSION

The results suggested that the dual drug-loaded system developed in this study might become a highly effective therapy for periodontal disease.

Micellar carriers for the delivery of multiple therapeutic agents

Multi-drug therapy is described as a simultaneous or sequential administration of two or more drugs with similar or different mechanisms of action and is recognized as a more efficient solution to combat successfully, various ailments. Polymeric micelles (PMs) are self-assemblies of block copolymers providing numerous opportunities for drug delivery. To date various micellar formulations were studied for delivery of drugs, nutraceuticals and genes; a few of them are in clinical trials. It was observed that there is an immense need for the development of PMs embedding multiple therapeutic agents to combat various ailments, including cancers, HIV/AIDS, malaria, multiple sclerosis, hypertension, infectious diseases, cardiovascular and metabolic diseases, immune disorders and many psychiatric disorders. Several combinations of drug-drug, drug-nutraceutical, drug-gene and drug-siRNA explored to date are detailed in this review, with a special emphasis on their potential and future perspectives. A summary of various preparation methods, characterization techniques and applications of PMs are also provided. This review presents a holistic approach on multi-drug delivery using micellar carriers and emphasizes on the development of therapeutic hybrids embedding novel combinations for safer and effective therapy.

An insight on electrospun-nanofibers-inspired modern drug delivery system in the treatment of deadly cancers

This review gives an insight into the process of electrospinning, its essential parameters, the types of drug incorporation and the works reported on common dreadful cancers.