Herein, hydroxypropyl-beta-cyclodextrin (HPβCD) inclusion complex (IC) of a hydrophobic drug, sulfisoxazole (SFS) was incorporated in hydroxypropyl cellulose (HPC) nanofibers (HPC/SFS/HPβCD-IC-NF) ...via electrospinning. SFS/HPβCD-IC was characterized by DSC to investigate the formation of inclusion complex and the stoichiometry of the complex was determined by Job's plot. Modeling studies were also performed on SFS/HPβCD-IC using ab initio technique. SEM images depicted the defect free uniform fibers and confirmed the incorporation of SFS/HPβCD-IC in nanofibers did not alter the fiber morphology. XRD analyses showed amorphous distribution of SFS/HPβCD-IC in the fiber mat. Release studies were performed in phosphate buffered saline (PBS). The results suggest higher amount of SFS released from HPC/SFS/HPβCD-IC-NF when compared to free SFS containing HPC nanofibers (HPC/SFS-NF). This was attributed to the increased solubility of SFS by inclusion complexation. Sandwich configurations were prepared by placing HPC/SFS/HPβCD-IC-NF between electrospun PCL nanofibrous mat (PCL-HPC/SFS/HPβCD-IC-NF). Consequently, PCL-HPC/SFS/HPβCD-IC-NF exhibited slower release of SFS as compared with HPC/SFS/HPβCD-IC-NF. This study may provide more efficient future strategies for developing delivery systems of hydrophobic drugs.
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Core-shell nanofibers were designed via electrospinning using inclusion complex (IC) of model hydrophobic drug (curcumin, CUR) with cyclodextrin (CD) in the core and polymer ...(polylactic acid, PLA) in the shell (cCUR/HPβCD-IC-sPLA-NF). CD-IC of CUR and HPβCD was formed at 1:2 molar ratio. The successful formation of core-shell nanofibers was revealed by TEM and CLSM images. cCUR/HPβCD-IC-sPLA-NF released CUR slowly but much more in total than PLA-CUR-NF at pH 1 and pH 7.4 due to the restriction of CUR in the core of nanofibers and solubility improvement shown in phase solubility diagram, respectively. Improved antioxidant activity of cCUR/HPβCD-IC-sPLA-NF in methanol:water (1:1) is related with the solubility enhancement achieved in water based system. The slow reaction of cCUR/HPβCD-IC-sPLA-NF in methanol is associated with the shell inhibiting the quick release of CUR. On the other hand, cCUR/HPβCD-IC-sPLA-NF exhibited slightly higher rate of antioxidant activity than PLA-CUR-NF in methanol:water (1:1) owing to the enhanced solubility. To conclude, slow release of CUR was achieved by core-shell nanofiber structure and inclusion complexation of CUR with HPβCD provides high solubility. Briefly, electrospinning of core-shell nanofibers with CD-IC core could offer slow release of drugs as well as solubility enhancement for hydrophobic drugs.
Here, we report a facile production of citral/cyclodextrin (CD) inclusion complex (IC) nanofibers (NFs) from three types of CDs (hydroxypropyl-beta-cyclodextrin (HPβCD), ...hydroxypropyl-gamma-cyclodextrin (HPγCD), and methylated-beta-cyclodextrin (MβCD)) by an electrospinning technique without the need of any polymeric carrier matrix. Self-standing nanofibrous webs of citral/CD-IC nanofibers (citral/CD-IC-NF) with uniform fiber morphology have been successfully electrospun from aqueous solutions of citral/CD-IC. Thanks to the inclusion complex formed with CDs, the efficient preservation of citral (up to ~80%) in citral/CD-IC-NFs was observed. In addition, the citral/CD-IC-NFs have shown ~50% preservation of citral for 15 days at room temperature even though citral has a highly volatile nature. The enhanced thermal stability of citral (~100⁻300°C) in citral/CD-IC-NFs compared to pure citral (~50⁻165°C) has been observed. Moreover, citral/CD-IC-NFs tended to disintegrate in water very quickly. To summarize, citral was efficiently encapsulated in citral/CD-IC-NFs, and these citral/CD-IC-NFs have been shown to be fast dissolving. In citral/CD-IC-NFs, citral/CD-ICs have enhanced water solubility of citral along with high-temperature stability and a longer shelf-life.
The composite fibrous films were developed from zein and poly(lactic acid) (PLA) by incorporating carvacrol at three different concentrations (5, 10 and 20%) using electrospinning. The morphology and ...size of fibers obtained from both zein and PLA were affected by the level of the incorporated carvacrol. The Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA) results showed that carvacrol was encapsulated in electrospun zein and PLA fibers. The antioxidant activity of carvacrol loaded zein fibers ranged from 62 to 75%, while antioxidant capacity of PLA fibers varied from 53 to 65% for 5–20% carvacrol content. The composite fibrous films showed a sustained diffusion controlled release behavior. Preliminary studies on whole wheat bread samples showed that carvacrol loaded electrospun zein and PLA fibers are able to preserve bread samples, indicating that they are good candidates for active food packaging applications to extend the shelf life of whole wheat bread.
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•Carvacrol was successfully encapsulated in electrospun zein and PLA fibers using electrospinning process.•Surface morphology of fibers significantly affected the release of carvacrol from electrospun fibers.•Carvacrol loaded electrospun fibers exhibited antioxidant activities.•The composite fibrous zein and PLA films at 20% carvacrol content inhibited 99.6 and 91.3% of the growth of mold and yeast.
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•PCL NF encapsulating α-TC and α-TC/β-CD-IC was produced by electrospinning.•AO activity of PCL/α-TC/β-CD-IC-NF was higher than PCL/α-TC-NF in methanol:water.•AO activity of released ...α-TC was higher from PCL/α-TC/β-CD-IC-NF than PCL/α-TC-NF.•PCL/α-TC/β-CD-IC-NF protected α-TC from UV-light more efficiently than PCL/α-TC-NF.
Cyclodextrin inclusion complexes (CD-ICs) can be encapsulated into electrospun nanofibers in order to achieve delivery systems having high surface area and highly porous nanofibrous structures. In this study, a well-known antioxidant molecule, α-tocopherol (α-TC) (vitamin E) was chosen as an active agent for inclusion complexation with β-cyclodextrin. Polycaprolactone (PCL) nanofibers encapsulating α-tocopherol/β-cyclodextrin inclusion complex (α-TC/β-CD-IC) which has high antioxidant activity and photostability was produced via electrospinning (PCL/α-TC/β-CD-IC-NF). The formation of α-TC/β-CD-IC was confirmed by XRD. Phase solubility studies showed An-type complex formation between α-TC and β-CD. SEM revealed that bead-free nanofibers were successfully produced from PCL/α-TC/β-CD-IC system. PCL nanofibers encapsulating α-TC without CD-IC was also produced for comparison (PCL/α-TC-NF). Antioxidant test results showed that PCL/α-TC/β-CD-IC-NF had higher antioxidant activity as compared to PCL/α-TC-NF in methanol:water (1:1) system due to the stabilization and solubility increment of α-TC in the cavity of β-CD. PCL/α-TC/β-CD-IC-NF was more stable against UV-light when compared to PCL/α-TC-NF due to the presence of inclusion complexation. In brief, PCL/α-TC/β-CD-IC-NF with the advantages of having nanofibrous structure and encapsulating CD-ICs, may serve as a novel route for administration of α-TC due to its higher antioxidant activity and better UV-light stability.
Electrospun cellulose acetate nanofibers (CA-NF) have been modified with perfluoro alkoxysilanes (FS/CA-NF) for tailoring their chemical and physical features aiming oil–water separation purposes. ...Strikingly, hybrid FS/CA-NF showed that perfluoro groups are rigidly positioned on the outer surface of the nanofibers providing superhydrophobic characteristic with a water contact angle of ∼155°. Detailed analysis showed that hydrolysis/condensation reactions led to the modification of the acetylated β(1 → 4) linked d-glucose chains of CA transforming it into a superhydrophobic nanofibrous mat. Analytical data have revealed that CA-NF surfaces can be selectively controlled for fabricating the durable, robust and water resistant hybrid electrospun nanofibrous mat. The –OH groups available on the CA structure allowed the basic sol–gel reactions started by the reactive FS hybrid precursor system which can be monitored by spectroscopic analysis. Since alkoxysilane groups on the perfluoro silane compound are capable of reacting for condensation together with the CA, superhydrophobic nanofibrous mat is obtained via electrospinning. This structural modification led to the facile fabrication of the novel oil/water nanofibrous separator which functions effectively demonstrated by hexane/oil and water separation experiments. Perfluoro groups consequently modified the hydrophilic CA nanofibers into superhydrophobic character and therefore FS/CA-NF could be quite practical for future applications like water/oil separators, as well as self-cleaning or water resistant nanofibrous structures.
•The formation of cyclodextrin-inclusion complex (CD-IC) was proved by experimental and computational techniques.•Thymol/γ-CD-IC (2:1) has higher preservation rate and stability than thymol/γ-CD-IC ...(1:1).•Zein-thymol/γ-CD-IC-nanofibrous webs (2:1) released much more thymol than zein-thymol/γ-CD-IC- nanofibrous webs (1:1).•Zein-thymol/γ-CD-IC-nanofibrous webs (2:1) reduced the bacterial count in beef stored for up to 5days at 4°C.
Thymol (THY)/γ-Cyclodextrin(γ-CD) inclusion complex (IC) encapsulated electrospun zein nanofibrous webs (zein-THY/γ-CD-IC-NF) were fabricated as a food packaging material. The formation of THY/γ-CD-IC (1:1 and 2:1) was proved by experimental (X-ray diffraction (XRD), thermal gravimetric analysis (TGA), 1H NMR) and computational techniques. THY/γ-CD-IC (2:1) exhibited higher preservation rate and stability than THY/γ-CD-IC (1:1). It is worth mentioning that zein-THY/γ-CD-IC-NF (2:1) preserved much more THY as observed in TGA and stability of THY/γ-CD-IC (2:1) was higher, as shown by a modelling study. Therefore, much more THY was released from zein-THY/γ-CD-IC-NF (2:1) than zein-THY-NF and zein-THY/γ-CD-IC-NF (1:1). Similarly, antibacterial activity of zein-THY/γ-CD-IC-NF (2:1) was higher than zein-THY-NF and zein-THY/γ-CD-IC-NF (1:1). It was demonstrated that zein-THY/γ-CD-IC-NF (2:1) was most effective in inhibiting the growth of bacteria on meat samples. These webs show potential application as an antibacterial food packaging material.
A series of new core-shell fibers were developed containing anticancer drugs (5-fluorouracil or ferulic acid) and their cyclodextrin inclusion complexes, with a gadolinium-based magnetic resonance ...imaging (MRI) contrast agent. These were prepared by electrospinning, a simple method for producing ultra-fine fibers through the application of a strong electrostatic force on a polymer solution. The shell of the fibers was formed from Eudragit S100, and the drugs were loaded in the core. Scanning electron microscopy images showed the formation of smooth ribbon-like fibers, with diameters ranging from 1.4 to 5.1 μm, and transmission electron microscopy reveals a transparent interface between the core and shell compartments. X-ray diffraction and differential scanning calorimetry data confirmed the encapsulation of the drug into the cyclodextrin cavity and the formation of amorphous solid dispersions in the fibers. Drug release from the systems at pH 1 and 7 showed that all the drug loading was released within one hour at pH 1. Based on these results, it is proposed that the relatively low molecular weight drugs were able to diffuse out of the system into the release medium at acidic pH, despite the insolubility of the shell polymer under these conditions. These findings have important implications for the design of electrospun drug delivery systems.
•Electrospun PET nanofibers were surface modified with cyclodextrin polymer (CDP).•Three different types of native CD (α-CD, β-CD and γ-CD) were used to form CDP.•Nanofibrous structure of PET mats ...was preserved after CDP surface modification.•PET/CDP nanofibers have shown enhanced mechanical and thermal properties.•PET/CDP nanofibers efficiently remove PAH (e.g. phenanthrene) from aqueous solution.
Surface modified electrospun polyester (PET) nanofibers with cyclodextrin polymer (CDP) were produced (PET/CDP). CDP formation onto electrospun PET nanofibers was achieved by polymerization between citric acid (CTR, crosslinking agent) and cyclodextrin (CD). Three different types of native CD (α-CD, β-CD and γ-CD) were used to form CDP. Water-insoluble crosslinked CDP coating was permanently adhered onto the PET nanofibers. SEM imaging indicated that the nanofibrous structure of PET mats was preserved after CDP surface modification process. PET/CDP nanofibers have shown rougher/irregular surface and larger fiber diameter when compared to untreated PET nanofibers. The surface analyses of PET/CDP nanofibers by XPS elucidated that CDP was present on the fiber surface. DMA analyses revealed the enhanced mechanical properties for PET/CDP where PET/CDP nanofibers have shown higher storage modulus and higher glass transition temperature compared to untreated PET nanofibers. The surface area of the PET/CDP nanofibers investigated by BET measurements showed slight decrease due to the presence of CDP coating compared to pristine PET nanofibers. Yet, it was observed that PET/CDP nanofibers were more efficient for the removal of phenanthrene as a model polycyclic aromatic hydrocarbon (PAH) from aqueous solution when compared to pristine PET nanofibers. Our findings suggested that PET/CDP nanofibers can be a very good candidate as a filter material for water purification and waste treatment owing to their very large surface area as well as inclusion complexation capability of surface associated CDP.
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•Quercetin (QU)/β-CD-IC was incorporated into electrospun PAA NF via electrospinning.•β-CD was used for both crosslinking of nanofibres and inclusion of QU.•Stoichiometry of IC was ...determined as 1:1 by phase solubility and modelling studies.•Release of QU from PAA/QU/β-CD-IC-NF was slower and more than PAA/QU/β-CD-IC-film.•PAA/QU/β-CD-IC-NF exhibited quite high antioxidant activity and photostability.
Electrospinning of polyacrylic acid (PAA) nanofibres (NF) incorporating β-cyclodextrin inclusion complex (β-CD-IC) of quercetin (QU) was performed. Here, β-CD was used as not only the crosslinking agent for PAA nanofibres but also as a host molecule for inclusion of QU. The phase solubility test showed enhanced solubility of QU due to the inclusion complexation; in addition, the stoichiometry of QU/β-CD-IC was determined to be 1:1. Computational modelling studies confirmed that 1:1 and 1:2 complex formation are desirable; 1:1 complex formation was chosen to have higher weight loading of QU. SEM images showed that PAA/QU/β-CD-IC-NF were bead-free and uniform. XRD indicated that PAA/QU/β-CD-IC-NF were amorphous in nature without the crystalline peaks of QU. Comparative results revealed that the release profile of QU from PAA/QU/β-CD-IC-NF was much slower but greater in total than from PAA/QU/β-CD-IC-film. Moreover, high antioxidant activity and photostability of QU was achieved in PAA/QU/β-CD-IC-NF.
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