Electrospun polycaprolactone nanofibers as a potential oromucosal delivery system for poorly water-soluble drugs

In vitro and in vivo evaluation of linezolid loaded electrospun PLGA and PLGA/PCL fiber mats for prophylaxis and treatment of MRSA induced prosthetic infections

In this study, it was aimed to formulate linezolid loaded electrospun PLGA and PCL fiber mats doing controlled drug release, to be used in the treatment and prophylaxis of the prosthesis related infections. The effect of PLGA concentration, PLGA to PCL ratio and the amount of linezolid on the fiber and mat properties were examined. Fiber diameter has been shown to increase with increasing amount of PLGA and linezolid. Increase in PLGA amount resulted in reduced linezolid release, whereas increase in linezolid amount resulted in increased drug release. All PLGA fiber mats have shown to have favorable encapsulation efficiency (≥73%) and mechanical properties. Encapsulation efficiency and the mechanical properties deteriorated with the addition of PCL to the formulations. PLGA fiber mats have shown a biphasic controlled release and in vitro antibacterial activity against methicillin-resistant Staphylococcus aureus (MRSA), pattern up to one month. The formulation selected as the optimum has been evaluated in vivo on the infected rats, which had prosthetic implantation after bone fracture. Consequently, it has been demonstrated microbiologically and histopathologically that a more efficient therapy and prophylaxis have been achieved with a 37-fold lower dose of linezolid.

Fast Dissolving Oral Drug Delivery System Based on Electrospun Nanofibrous Webs of Cyclodextrin/Ibuprofen Inclusion Complex Nanofibers

In this study, the polymer-free electrospinning was performed in order to produce cyclodextrin/ibuprofen inclusion complex nanofibers, which could have potential as the fast dissolving oral drug delivery system. Ibuprofen is a poorly water-soluble nonsteroidal anti-inflammatory drug; however, the water solubility of ibuprofen can be significantly enhanced by inclusion complexation with cyclodextrins. Here, hydroxypropyl-beta-cyclodextrin (HPβCyD) was chosen both as a nanofiber matrix and host molecule for inclusion complexation in order to enhance water solubility and fast dissolution of ibuprofen. Ibuprofen was inclusion-complexed with HPβCyD in highly concentrated aqueous solutions of HPβCyD (200%, w/v) having two different molar ratios: 1:1 and 2:1 (HPβCyD/ibuprofen). The HPβCyD/ibuprofen-IC (1:1) aqueous solution was turbid having some undissolved/uncomplexed ibuprofen, whereas HPβCyD/ibuprofen-IC (2:1) aqueous solution was homogeneous and clear, indicating that ibuprofen was totally complexed with HPβCyD and becomes water soluble. Then, both HPβCyD/ibuprofen-IC solutions (1:1 and 2:1) were electrospun into bead-free and uniform nanofibers having ∼200 nm fiber diameter. The electrospun HPβCyD/ibuprofen-IC nanofibers were obtained as nanofibrous webs having self-standing and flexible character, which is appropriate for fast dissolving oral drug delivery systems. Ibuprofen was completely preserved during the electrospinning process, and the resulting electrospun HPβCyD/ibuprofen-IC nanofibers were produced without any loss of ibuprofen by preserving the initial molar ratio of 1:1 and 2:1 (HPβCyD/ibuprofen). X-ray diffraction and differential scanning calorimetry measurements indicated the presence of some crystalline ibuprofen in HPβCyD/ibuprofen-IC (1:1) nanofibers, whereas ibuprofen was totally in the amorphous state in HPβCyD/ibuprofen-IC (2:1) nanofibers. Nonetheless, both HPβCyD/ibuprofen-IC (1:1 and 2:1) nanofibrous webs have shown very fast dissolving character when contacted with water or when wetted with artificial saliva. In brief, our results revealed that electrospun HPβCyD/ibuprofen-IC nanofibrous webs have potential as fast dissolving oral drug delivery systems.

Electrospun fibers and their application in drug controlled release, biological dressings, tissue repair, and enzyme immobilization

Electrospinning is a method of preparing microfibers or nanofibers by using an electrostatic force to stretch the electrospinning fluid. Electrospinning has gained considerable attention in many fields due to its ability to produce continuous fibers from a variety of polymers and composites in a simple way. Electrospun nanofibers have many merits such as diverse chemical composition, easily adjustable structure, adjustable diameter, high surface area, high porosity, and good pore connectivity, which give them broad application prospects in the biomedical field. This review systematically introduced the factors influencing electrospinning, the types of electrospun fibers, the types of electrospinning, and the detailed applications of electrospun fibers in controlled drug release, biological dressings, tissue repair and enzyme immobilization fields. The latest progress of using electrospun fibers in these fields was summarized, and the main challenges to be solved in electrospinning technology were put forward.

Electrospinning Nanofibers for Therapeutics Delivery

The limitations of conventional therapeutic drugs necessitate the importance of developing novel therapeutics to treat diverse diseases. Conventional drugs have poor blood circulation time and are not stable or compatible with the biological system. Nanomaterials, with their exceptional structural properties, have gained significance as promising materials for the development of novel therapeutics. Nanofibers with unique physiochemical and biological properties have gained significant attention in the field of health care and biomedical research. The choice of a wide variety of materials for nanofiber fabrication, along with the release of therapeutic payload in sustained and controlled release patterns, make nanofibers an ideal material for drug delivery research. Electrospinning is the conventional method for fabricating nanofibers with different morphologies and is often used for the mass production of nanofibers. This review highlights the recent advancements in the use of nanofibers for the delivery of therapeutic drugs, nucleic acids and growth factors. A detailed mechanism for fabricating different types of nanofiber produced from electrospinning, and factors influencing nanofiber generation, are discussed. The insights from this review can provide a thorough understanding of the precise selection of materials used for fabricating nanofibers for specific therapeutic applications and also the importance of nanofibers for drug delivery applications.

Electrospun essential oil-polycaprolactone nanofibers as antibiofilm surfaces against clinical Candida tropicalis isolates

OBJECTIVE

As an approach to prevent biofilm infections caused by Candida tropicalis on various surfaces, determination of effect of biodegradable polycaprolactone nanofibers (PCLNFs) with different concentrations of two different essential oils were tested in this study.

RESULTS

Both of the tested essential oils exhibited antifungal effect (minimal inhibitory concentration; 0.25-0.49 µL/mL, minimal fungicidal concentration; 0.25-0.49 µL/mL, depending on the C. tropicalis strain) (Zone of inhibition caused by 500 μL/mL concentration of oils; 28-56 mm). 0, 2, 4% clove oil PCLNFs and 0, 2, 4% red thyme oil-PCLNFs were free from bead formation and uniform in diameter. Diameters of all essential oil containing PCLNFs were ranged from 760 to 1100 nm and were significantly different from 0% essential oil-PCLNF (P < 0.05). 0, 2, 4% clove oil-PCLNFs were significantly more hydrophobic compared to 8% clove oil-PCLNF (P < 0.01), whereas 0% and 2% red thyme oil-PCLNFs were significantly more hydrophobic compared to 4% and 8% red thyme oil PCLNFs (P < 0.01). Highest amount of biofilm inhibition was observed by 4% clove oil-PCLNF and by 4% red thyme oil-PCLNF.

CONCLUSIONS

Clove and red thyme oils may be used not only as antifungals but also as biofilm inhibitive agents on surfaces of biomaterials that are frequently contaminated by C. tropicalis, when they are incorporated into PCLNFs.

Fabrication of Electrospun Polymer Nanofibers with Diverse Morphologies

Fiber structures with nanoscale diameters offer many fascinating features, such as excellent mechanical properties and high specific surface areas, making them attractive for many applications. Among a variety of technologies for preparing nanofibers, electrospinning is rapidly evolving into a simple process, which is capable of forming diverse morphologies due to its flexibility, functionality, and simplicity. In such review, more emphasis is put on the construction of polymer nanofiber structures and their potential applications. Other issues of electrospinning device, mechanism, and prospects, are also discussed. Specifically, by carefully regulating the operating condition, modifying needle device, optimizing properties of the polymer solutions, some unique structures of core⁻shell, side-by-side, multilayer, hollow interior, and high porosity can be obtained. Taken together, these well-organized polymer nanofibers can be of great interest in biomedicine, nutrition, bioengineering, pharmaceutics, and healthcare applications.

Recent advances in electrospun for drug delivery purpose

Electrospun, an advanced technology, has been successfully employed for fibre production and offers many merits in novel drug delivery systems (DDSs). In recent years, electrospun has gained significant attention and attraction of the scientists in soaring numbers. This technology is superior to other technologies in fabricating the fibres which range from micrometers to manometers scale. The selection of appropriate polymers, electrospun processes and electrospun parameters play important roles in controlling the drug release while, treating serious illness. Besides, electrospraying process has similar characteristics to the electrospun and is presented briefly here. Further, in vivo and in vitro evaluations of the electrospun nanofibers are comprehensively discussed. In addition, the electrospun nanotechnology has been exploited to design drug release systems, investigate drug's pharmacokinetics and further develop DDS. The electrospun nanofibers improve bioactivity of various types of drugs including water-insoluble, soluble, anticancer and antibacterial drugs and genetic materials. In the end, the prospects and challenges in the process of designing drug-loaded electrospun nanofibers are discussed in detail.

Impact of PCL nanofiber mat structural properties on hydrophilic drug release and antibacterial activity on periodontal pathogens

Electrospinning enables to design and manufacture novel drug delivery systems capable of advancing the local antibacterial therapy. In this study, two hydrophilic drugs - metronidazole and ciprofloxacin hydrochloride - were loaded both individually and in combination into hydrophobic poly(ε-caprolactone) (PCL) matrix using electrospinning. We aimed to develop prolonged release drug delivery systems suitable for the treatment of periodontal diseases and understand how different rarely studied structural features, such as nanofiber mat thickness, surface area, wettability, together with intrinsic properties, like solid state and localization of incorporated drugs in nanofibers, affect the drug release. Furthermore, the safety of nanofiber mats was assessed in vitro on fibroblasts, and their antibacterial activity was tested on selected strains of periodontopathogenic bacteria. The results showed that the structural properties of nanofiber mat are crucial in particular drug-polymer combinations, affecting the drug release and consequently the antibacterial activity. The hydrophobicity of a PCL nanofiber mat and its thickness are the key characteristics in prolonged hydrophilic drug release, but only when wetting is the rate-limiting step for the drug release. Combination of drugs showed beneficial effects by inhibiting the growth of all tested pathogenic bacterial strains important in periodontal diseases.

Synthesis of a Novel Electrospun Polycaprolactone Scaffold Functionalized with Ibuprofen for Periodontal Regeneration: An In Vitro andIn Vivo Study

Ibuprofen (IBU) has been shown to improve periodontal treatment outcomes. The aim of this study was to develop a new anti-inflammatory scaffold by functionalizing an electrospun nanofibrous poly-ε-caprolactone membrane with IBU (IBU-PCL) and to evaluate its impact on periodontal inflammation, wound healing and regeneration in vitro and in vivo. IBU-PCL was synthesized through electrospinning. The effects of IBU-PCL on the proliferation and migration of epithelial cells (EC) and fibroblasts (FB) exposed to Porphyromonas gingivlais lipopolysaccharide (Pg-LPS) were evaluated through the AlamarBlue test and scratch assay, respectively. Anti-inflammatory and remodeling properties were investigated through Real time qPCR. Finally, the in vivo efficacy of the IBU-PCL membrane was assessed in an experimental periodontitis mouse model through histomorphometric analysis. The results showed that the anti-inflammatory effects of IBU on gingival cells were effectively amplified using the functionalized membrane. IBU-PCL reduced the proliferation and migration of cells challenged by Pg-LPS, as well as the expression of fibronectin-1, collagen-IV, integrin α3β1 and laminin-5. In vivo, the membranes significantly improved the clinical attachment and IBU-PCL also reduced inflammation-induced bone destruction. These data showed that the IBU-PCL membrane could efficiently and differentially control inflammatory and migratory gingival cell responses and potentially promote periodontal regeneration.

Cilostazol-Loaded Poly(ε-Caprolactone) Electrospun Drug Delivery System for Cardiovascular Applications

PURPOSE

The study discusses the value of electrospun cilostazol-loaded (CIL) polymer structures for potential vascular implant applications.

METHODS

Biodegradable polycaprolactone (PCL) fibers were produced by electrospinning on a rotating drum collector. Three different concentrations of CIL: 6.25%, 12.50% and 18.75% based on the amount of polymer, were incorporated into the fibers. The fibers were characterized by their size, shape and orientation. Materials characterization was carried out by Fourier Transformed Infrared spectroscopy (FTIR), Raman spectroscopy, differential scanning calorimetry (DSC) and X-ray diffraction (XRD). In vitro drug release study was conducted using flow-through cell apparatus (USP 4).

RESULTS

Three-dimensional structures characterized by fibers diameter ranging from 0.81 to 2.48 μm were in the range required for cardiovascular application. DSC and XRD confirmed the presence of CIL in the electrospun fibers. FTIR and Raman spectra confirmed CIL polymorphic form. Elastic modulus values for PCL and the CIL-loaded PCL fibers were in the range from 0.6 to 1.1 GPa. The in vitro release studies were conducted and revealed drug dissolution in combination with diffusion and polymer relaxation as mechanisms for CIL release from the polymer matrix.

CONCLUSIONS

The release profile of CIL and nanomechanical properties of all formulations of PCL fibers demonstrate that the cilostazol loaded PCL fibers are an efficient delivery system for vascular implant application.

A Summary of Electrospun Nanofibers as Drug Delivery System: Drugs Loaded and Biopolymers Used as Matrices

Recently, electrospun polymeric nanofibers have proven to be an interesting strategy for drug delivery systems application. The high surface-to-volume ratio of the fibers can improve some processes, such as cell binding and proliferation, drug loading, and mass transfer processes. One of the most important and studied areas of electrospinning is in the drug delivery field, for the controlled release of active substances ranging from antibiotics and anticancer agents to macromolecules such as proteins and DNA. The advantage of this method is that a wide variety of low solubility drugs can be loaded into the fibers to improve their bioavailability or to attain controlled release. This review presents an overview of the reported drugs loaded into polymeric nanofibers, to be used as drug delivery systems. For instance, it presents the reports on drugs with different bioactivities such as antiinflammatory, anti-microbial, anticancer, cardiovascular, anti-histamine, gastrointestinal, palliative and contraceptive drugs, etc. It also analyzes the electrospinning techniques used in each system, as well as the polymers used as matrices for the preparation of the nanofibers; unfolding the advantages of electrospun polymeric nanofibers over other drug delivery systems. This review intends to enlist and summarize the reported literature concerning this topic. In addition, it proposes future research in the field.

Novel strategies for the formulation and processing of poorly water-soluble drugs

Low aqueous solubility of active pharmaceutical ingredients presents a serious challenge in the development process of new drug products. This article provides an overview on some of the current approaches for the formulation of poorly water-soluble drugs with a special focus on strategies pursued at the Center of Pharmaceutical Engineering of the TU Braunschweig. These comprise formulation in lipid-based colloidal drug delivery systems and experimental as well as computational approaches towards the efficient identification of the most suitable carrier systems. For less lipophilic substances the preparation of drug nanoparticles by milling and precipitation is investigated for instance by means of microsystem-based manufacturing techniques and with special regard to the preparation of individualized dosage forms. Another option to overcome issues with poor drug solubility is the incorporation into nanospun fibers.

A fiber distribution model for predicting drug release rates

Sustained drug release can be achieved by loading a drug into polymer material. The drug release can then be controlled for potential use in various biomedical applications. A model for drug release from a polymeric fibrous scaffold, which takes into account the distribution of fiber diameters within its structure, is developed here. It is demonstrated that the fiber diameter distribution significantly affects the drug release profile from electrospun scaffolds. The developed model indicates that altering the fiber distribution can be used as an additional tool to achieve an appropriate drug release profile. Using published data, it was demonstrated that an application of the model allows a more precise calculation of the drug diffusion coefficient within the polymer, which is important for predicting drug release rates from fabricated materials.

Ketoprofen-loaded Eudragit electrospun nanofibers for the treatment of oral mucositis

Purpose

The purpose of this study was to formulate ketoprofen (KET)-loaded Eudragit L and Eudragit S nanofibers (NFs) by the electrospinning technique for buccal administration to treat oral mucositis as a safe alternative to orally administered KET, which causes gastrointestinal tract (GIT) side effects.

Materials and methods

NFs were prepared by electrospinning using Eudragit L and Eudragit S. Several variables were evaluated to optimize NF formulation, such as polymer types and concentrations, applied voltage, flow rate and drug concentrations. Differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) and analyses of drug contents, hydration capacity, surface pH, drug release and ex vivo permeation were performed to evaluate the NFs. The selected formulation (F1) was evaluated in vivo on induced oral mucositis in rabbits.

Results

SEM revealed that 20% polymer formed smooth and bead-free NFs. DSC results confirmed the amorphous nature of KET in the NFs. FTIR confirmed hydrogen bond formation between the drug and polymer, which stabilized the NFs. Both formulations (F1 and F2) had an acceptable surface pH. The drug loading was >90%. The amount of KET released from NF formulations was statistically significantly higher (P≤0.001) than that released from the corresponding solvent-casted films. The complete release of KET from F1 occurred within 2 hours. Ex vivo permeation study revealed that only a small fraction of drug permeated from F1, which was a better candidate than F2 for local buccal delivery. In vivo evaluation of F1 on oral mucositis induced in rabbits demonstrated that F1 reduced the clinical severity of mucositis in rabbits under the current experimental conditions. The attenuated clinical severity was accompanied by a marked reduction in inflammatory infiltrate and re-epithelization of the epithelial layer.

Conclusion

Eudragit L100 nanofibers (EL-NF) loaded with KET (F1) suppressed the inflammatory response associated with mucositis, which confirmed the efficacy of local buccal delivery of KET-loaded EL-NF in treating oral mucositis.

Quasi-SMILES for Nano-QSAR Prediction of Toxic Effect of Al2O3 Nanoparticles

The level of malondialdehyde (MDA) in wet tissue of different organs is utilized as a measure of toxic effect. The numerical data on the concentration of MDA in wet tissue of liver, kidneys, brain, and heart of rat is examined as the endpoint which are impacted by different dose (mg/kg), exposure time (3 and 14 days) and single oral treatment of aluminium nano-oxide (Al2O3) with 30 nm or 40 nm. An attempt to develop predictive model for this endpoint has been carried out in this work. SMILES is a traditional tool to represent molecular structure for QSPRs/QSARs. In contrast to traditional SMILES, so-called quasi-SMILES can be a tool to build up quantitative features – property / activity relationships (QFPRs/QFARs) for endpoints which are not defined by solely molecular structure, but by a group of physicochemical and/or biochemical conditions. The quasi-SMILES is the representation of the above eclectic conditions whereas the QFPR/QFAR are models of endpoints which are modified under impacts of these eclectic conditions.

Electrospun organic–inorganic nanohybrids as sustained release drug delivery systems

Novel organic–inorganic nanohybrids have been prepared, and are found to provide long-term extended drug release.

Amphiphilic electrospun scaffolds of PLLA–PEO–PPO block copolymers: preparation, characterization and drug-release behaviour

Drug-loaded nanofibrous scaffolds containing hydrophilic or hydrophobic drugs presented encapsulation efficiency, distribution and release dependent on copolymer composition.

Inclusion complexes of anhydrolycorine with cyclodextrins: preparation, characterization, and anticancer activity

This article describes the preparation of a series of inclusion complexes of anhydrolycorine with three cyclodextrins (CDs), namely β-CD, γ-CD, and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), and their successful characterization through UV, TG, DSC, XRD, SEM, 1H NMR, and 2D NMR spectroscopies. The results demonstrated that the water solubility of anhydrolycorine increased notably by about 23–42 times after the inclusion complexation with these CDs. Furthermore, preliminary in vitro cytotoxicity experiments on human colon cancer cell lines HT-29, SW480, HCT116, and DLD-1 were also performed, and the complexes showed remarkable anticancer activity against HT-29, SW480, and HCT116. These results suggested that the inclusion complexes would be potentially useful for applications for human colon cancer chemotherapy.

Novel electrospun nanofibrous matrices prepared from poly(lactic acid)/poly(butylene adipate) blends for controlled release formulations of an anti-rheumatoid agent

In the present work, a series of novel formulations consisting of poly(lactic acid)/poly(butylene adipate) (PLA/PBAd) electrospun blends was examined as controlled release matrices for Leflunomide's active metabolite, Teriflunomide (TFL). The mixtures were prepared using different ratios of PLA and PBAd in order to produce nanofibrous matrices with different characteristics. Miscibility studies of the blended polymeric fibers were performed through differential scanning calorimetry (DSC) and X-ray diffractometry (XRD). Hydrolytic degradation in the prepared fibers was evaluated at 37°C using a phosphate buffered saline solution. Different concentrations of (TFL) (5, 10, 15wt.%) were incorporated into nanofibers for examining the drug release behavior in simulated body fluids (SBF), at 37°C. The drug-loaded nanofibrous formulations were further characterized by Fourier Transform Infrared Spectroscopy (FTIR) spectroscopy, DSC and XRD. Gel permeation chromatography (GPC) analysis was used to evaluate the mechanism of TFL release. Artificial neural networks (ANN) and multi-linear-regression (MLR) models were used to evaluate the effect of % content of PBAd (X1) and TFL (X2) on an initial burst effect and a dissolution behavior. It was found that PLA/PBAd nanofibers have different diameters depending on the ratio of used polyesters and added drug. TFL was incorporated in an amorphous form inside the polymeric nanofibers. In vitro release studies reveal that a drug release behavior is correlated with the size of the nanofibers, drug loading and matrix degradation after a specific time. ANN dissolution modeling showed increased correlation efficacy compared to MLR.

New Biopolymer Nanoparticles Improve the Solubility of Lipophilic Megestrol Acetate

As many substances are poorly soluble in water and thus possess decreased bioavailability, creating orally administered forms of these substances is a challenge. The objective of this study was to determine whether the solubility of megestrol acetate, a Biopharmaceutical Classification System (BCS) class II drug, can be improved by using a newly-synthesized surfactant (Rofam 70: a rapeseed methyl ester ethoxylate) and compare it with two references surfactants (Tween 80, Pluronic F68) at three different pH values. Spectrophotometry was used to compare the solubility profiles in the presence of three tested surfactants at pH 5.0, 7.4 and 9.0. Rapeseed methyl ester ethoxylate was found to improve the solubility of the BCS Class II drug and increase its bioavailability; It increased drug solubility more effectively than Pluronic F68. Its cytotoxicity results indicate its possible value as a surfactant in Medicine and Pharmacy.

Long-Term Sustained Ciprofloxacin Release from PMMA and Hydrophilic Polymer Blended Nanofibers

Nanofibers represent an attractive novel drug delivery system for prolonged and controlled release. However, sustained release of hydrophilic drugs, like ciprofloxacin hydrochloride (CIP), from polymeric nanofibers is not an easy task. The present study investigates the effect of different hydrophobic polymers (PCL and PMMA) alone in monolithic nanofibers or with hydrophilic polymers (PVA, PEO, and chitosan) in blended nanofibers aiming to achieve sustained CIP release. CIP release from PCL nanofibers was 46% and from PMMA just 1.5% over 40 day period. Thus, PMMA holds great promise for modification of CIP release from blended nanofibers. PMMA blends with 10% PEO, PVA, or chitosan were used to electrospin nanofibers from solution in the mixture of acetic and formic acid. These nanofibers exhibited different drug-release profiles: PEO containing nanofiber mats demonstrated high burst effect, chitosan containing mats revealed very slow gradual release, and PVA containing mats yielded smaller burst effect with favorable sustained release. We have also shown that gradual sustain release of antibiotic like CIP can be additionally tuned over 18 days with various blend ratios of PMMA with PVA or chitosan reaching almost 100%. A mathematical model in agreement with the experimental observation revealed that the sustained CIP release from the blended nanofibers corresponded to the two-stage desorption process.

Synthesis and characterization of flurbiprofen axetil-loaded electrospun MgAl-LDHs/poly(lactic-co-glycolic acid) composite nanofibers

A model drug FA was intercalated into the interlayers of layered double hydroxides (LDHs) and the particles were dispersed into the PLGA nanofibers to form a carrier for drug sustained release.