Formulation of a fast-disintegrating drug delivery system from cyclodextrin/naproxen inclusion complex nanofibrous films.

Naproxen is a well-known non-steroidal anti-inflammatory drug (NSAID) that suffers from limited water solubility. The inclusion complexation with cyclodextrin (CD) can eliminate this drawback and the free-standing nanofibrous film (NF) generated from these inclusion complexes (ICs) can be a promising alternative formula as an orally disintegrating drug delivery system. For this, naproxen/CD IC NFs were generated using the highly water soluble hydroxypropylated derivative of ßCD (HPßCD) with two different molar ratios of 1/1 and 1/2 (drug/CD). The complexation energy calculated by the modeling study demonstrated a more favorable interaction between HPßCD and naproxen for the 1/2 molar ratio than 1/1. HPßCD/naproxen IC NFs were generated with loading concentrations of ∼7-11% and without using toxic chemicals. HPßCD/naproxen IC NFs indicated a faster and enhanced release profile in aqueous medium compared to pure naproxen owing to inclusion complexation. Moreover, rapid disintegration in less than a second was achieved in an artificial saliva environment.

Functionalization of cotton nonwoven with cyclodextrin/lawsone inclusion complex nanofibrous coating for antibacterial wound dressing.

Functionalizing cotton to induce biological activity is a viable approach for developing wound dressing. This study explores the development of cotton-based wound dressing through coating with biologically active nanofibers. Bioactive compounds like lawsone offer dual benefits of wound healing and infection prevention, however, their limited solubility and viability hinder their applications. To address this, Hydroxypropyl-beta-cyclodextrin (HP-ß-CD) and Hydroxypropyl-gamma-cyclodextrin (HP-γ-CD) were employed. Inclusion complexations of CD/lawsone were achieved at 2:1 and 4:1 M ratios, followed by the fabrication of CD/lawsone nanofibrous systems via electrospinning. Phase solubility studies indicated a twofold increase in lawsone water-solubility with HP-ß-CD. Electrospinning yielded smooth and uniform nanofibers with an average diameter of ∼300-700 nm. The results showed that while specific crystalline peaks of lawsone are apparent in the samples with a 2:1 M ratio, they disappeared in 4:1, indicating complete complexation. The nanofibers exhibited ∼100 % loading efficiency of lawsone and its rapid release upon dissolution. Notably, antibacterial assays demonstrated the complete elimination of Escherichia coli and Staphylococcus aureus colonies. The CD/lawsone nanofibers also showed suitable antioxidant activity ranging from 50 % to 70 %. This integrated approach effectively enhances lawsone's solubility through CD complexation and offers promise for bilayer cotton-based wound dressings.

Green Synthesis of Polycyclodextrin/Drug Inclusion Complex Nanofibrous Hydrogels: pH-Dependent Release of Acyclovir.

The development of an approach or a material for wound healing treatments has drawn a lot of attention for decades and has been an important portion of the research in the medical industry. Especially, there is growing interest and demand for the generation of wound care products using eco-friendly conditions. Electrospinning is one of these methods that enables the production of nanofibrous materials with attractive properties for wound healing under mild conditions and by using sustainable sources. In this study, starch-derived cyclodextrin (hydroxypropyl-ß-cyclodextrin (HPßCD)) was used both for forming an inclusion complex (IC) with acyclovir, a well-known antiviral drug, and for electrospinning of free-standing nanofibers. The nanofibers were produced in an aqueous system, without using a carrier polymer matrix and toxic solvent/chemical. The ultimate HPßCD/acyclovir-IC nanofibers were thermally cross-linked by using citric acid, listed in the generally regarded as safe (GRAS) category by the US Food and Drug Administration (FDA). The cross-linked HPßCD/acyclovir-IC nanofibers displayed stability in aqueous medium. The hydrogel-forming feature of nanofibers was confirmed with their high swelling profile in water in the range of ∼610-810%. Cellulose acetate (CA)/acyclovir nanofibers were also produced as the control sample. Due to inclusion complexation with HPßCD, the solubility of acyclovir was improved, so cross-linked HPßCD/acyclovir-IC nanofibrous hydrogels displayed a better release performance compared to CA/acyclovir nanofibers. Here, a pH-dependent release profile was obtained (pH 5.4 and pH 7.4) besides their attractive swelling features. Therefore, the cross-linked HPßCD/acyclovir-IC nanofibrous hydrogel can be a promising candidate as a wound healing dressing for the administration of antiviral drugs by holding the unique properties of CD and electrospun nanofibers.

Encapsulation of antioxidant beta-carotene by cyclodextrin complex electrospun nanofibers: Solubilization and stabilization of beta-carotene by cyclodextrins.

Carotenoids act as effective antioxidant defense systems in humans as they scavenge molecular oxygen and peroxyl radicals. However, their poor water solubility and being susceptible to degradation driven by light and oxygen hinder their bioactivity, therefore, they should be stabilized by host matrices against oxidation. Here, ß-carotene was encapsulated in electrospun cyclodextrin (CD) nanofibers to increase its water-solubility and photostability to enhance its antioxidant bioactivity. ß-carotene/CD complex aqueous solutions were electrospun into nanofibers. The bead-free morphology of the ß-carotene/CD nanofibers was confirmed by SEM. The formation of ß-carotene/CD complexes was explored through computational modeling and experimentally by FTIR, XRD and solubility tests. The antioxidant activity of the fibers exposed to UV irradiation was demonstrated via a free radical scavenger assay, where ß-carotene/CD nanofibers revealed protection against UV radiation. Overall, this work reports the water-borne electrospinning of antioxidant ß-carotene/CD inclusion complex nanofibers, which stabilize the encapsulated ß-carotene against UV-mediated oxidation.

Fast-Disintegrating Nanofibrous Web of Pullulan/Griseofulvin-Cyclodextrin Inclusion Complexes.

Griseofulvin (GSF) is one of the most widely used antifungal suffering from low water solubility and limited bioavailability. Here, cyclodextrin (CD) derivatives of hydroxypropyl-beta-CD (HPßCD) known for its high-water solubility were used to form inclusion complexes (ICs) with GSF. Here, the molecular modeling study revealed the more efficient complex formation with 1:2 (guest:CD) stoichiometry, so ICs of GSF-HPßCD were prepared using a 1:2 molar ratio (GSF:HPßCD) and then mixed with pullulan (PULL) to generate nanofibers (NFs) using the electrospinning technique. PULL is a nontoxic water-soluble biopolymer and the ultimate PULL/GSF-HPßCD-IC NF was obtained with a defect-free fiber morphology having 805 ± 180 nm average diameter. The self-standing and flexible PULL/GSF-HPßCD-IC NF was achieved to be produced with a loading efficiency of ∼98% corresponding to ∼6.4% (w/w) of drug content. In comparison, the control sample of PULL/GSF NF was formed with a lower loading efficiency value of ∼72% which equals to ∼4.7% (w/w) of GSF content. Additionally, PULL/GSF-HPßCD-IC NF provided an enhanced aqueous solubility for GSF compared to PULL/GSF NF so a faster release profile with ∼2.5 times higher released amount was obtained due to inclusion complexation between GSF and HPßCD within the nanofibrous web. On the other hand, both nanofibrous webs rapidly disintegrated (∼2 s) in the artificial saliva medium that mimics the oral cavity environment. Briefly, PULL/GSF-HPßCD-IC NF can be a promising dosage formulation as a fast-disintegrating delivery system for antifungal oral administration owing to the improved physicochemical properties of GSF.

Advances in the development of cyclodextrin-based nanogels/microgels for biomedical applications: Drug delivery and beyond.

Nanogels/microgels are swollen cross-linked polymer networks with tunable physicochemical properties and are commonly employed for the effective delivery of hydrophilic drugs. By structural engineering, they can be adapted for the delivery of hydrophobic drugs. Likewise, the use of cyclodextrins (CDs) as pharmaceutical excipients in nanogels drastically boosts the loading capacity of lipophilic drugs while enhancing their stability, bioavailability, and permeability owing to their capability of hosting drugs in their somewhat lipophilic cavity. Here, the synthesis and biomedical applications of CD-based nanogels/microgels were compiled with regard to the CD's role in nanogel synthesis. Even though most applications focused on using CD molecules as functional motifs to carry drugs and construct nanogels for biomedical applications, others used CDs in engineering nanogels to benefit from their supramolecular complexation ability. The applications of CD-based nanogels for drug-mediated cancer/tumor therapy were also discussed. Finally, the review points to the challenges/horizons to boost their biomedical applications.

Ondansetron/Cyclodextrin inclusion complex nanofibrous webs for potential orally fast-disintegrating antiemetic drug delivery.

Ondansetron (ODS) is an effective antiemetic drug which suffers from limited solubility and bioavailability during oral administration due to first-pass metabolism. However, these limitations can be mitigated through inclusion complexation with cyclodextrins (CDs). In this study, we have reported the electrospinning of polymer-free, free-standing ODS/CD nanofibrous webs (NW), a promising approach for developing a fast-disintegrating delivery system of an antiemetic drug molecule. Highly water soluble hydroxypropyl-beta-cyclodextrins (HPßCD) were used as both complexation agent and electrospinning matrix. The computational study revealed that the 1/2 (drug/CD) stoichiometry was more favorable compared to 1/1. The ODS/HPßCD NW was obtained with higher loading efficiency (∼96 %) compared to the control sample of ODS/polyvinyl alcohol (PVA) NW (∼80 %). The amorphous distribution of ODS raised by complexation and the highly water-soluble nature of HPßCD resulted into faster and better release profile and quite faster disintegration property (∼2 s) in artificial saliva than polymeric ODS/PVA NW. Here, ODS/HPßCD NW was generated in the absence of a toxic solvent or chemical to enable the drug loading in an amorphous state. From all reasons above, ODS/HPßCD NW might be a promising alternative to the polymeric based systems for the purpose of fast-disintegrating oral drug delivery.

Antibacterial nanofibers of pullulan/tetracycline-cyclodextrin inclusion complexes for Fast-Disintegrating oral drug delivery.

Tetracycline is a widely used antibiotic suffering from poor water solubility and low bioavailability. Here, hydroxypropyl-beta-cyclodextrin (HPßCD) was used to form inclusion complexes (IC) of tetracycline with 2:1 M ratio (CD:drug). Then, tetracycline-HPßCD-IC was mixed with pullulan- a non-toxic, water-soluble biopolymer - to form nanofibrous webs via electrospinning. The electrospinning of pullulan/tetracycline-HPßCD-IC was yielded into defect-free nanofibers collected in the form of a self-standing and flexible material with the loading capacity of âˆ¼ 7.7 % (w/w). Pullulan/tetracycline nanofibers was also generated as control sample having the same drug loading. Tetracycline was found in the amorphous state in case of pullulan/tetracycline-HPßCD nanofibers due to inclusion complexation. Through inclusion complexation with HPßCD, enhanced aqueous solubility and faster release profile were provided for pullulan/tetracycline-HPßCD-IC nanofibers compared to pullulan/tetracycline one. Additionally, pullulan/tetracycline-HPßCD-IC nanofibers readily disintegrated when wetted with artificial saliva while pullulan/tetracycline nanofibers were not completely absorbed by the same simulate environment. Electrospun nanofibers showed promising antibacterial activity against both gram-positive and gram-negative bacteria. Briefly, our findings indicated that pullulan/tetracycline-HPßCD-IC nanofibers could be an attractive material as orally fast disintegrating drug delivery system for the desired antibiotic treatment thanks to its promising physicochemical and antibacterial properties.

Orally Fast Disintegrating Cyclodextrin/Prednisolone Inclusion-Complex Nanofibrous Webs for Potential Steroid Medications.

Prednisolone is a widely used immunosuppressive and anti-inflammatory drug type that suffers from low aqueous solubility and bioavailability. Due to the inclusion complexation with cyclodextrins (CDs), prednisolone's drawbacks that hinder its potential during the administration can be eliminated effectively. Here, we have early shown the electrospinning of free-standing nanofibrous webs of CD/prednisolone inclusion complexes (ICs) in the absence of a polymer matrix. In this study, hydroxypropyl-beta-CD (HPßCD) has been used to form ICs with prednisolone and generate nanofibrous webs with a drug loading capacity of ∼10% (w/w). Pullulan/prednisolone nanofibrous webs have been also fabricated as a control sample having the same drug loading (∼10%, w/w). It has been demonstrated that prednisolone has been found in an amorphous state in the HPßCD/prednisolone nanofibrous web due to inclusion complexation, while it has retained its crystal structure in the pullulan/prednisolone nanofibrous web. Therefore, the HPßCD/prednisolone IC nanofibrous web has shown a faster and enhanced release profile and superior disintegration feature in artificial saliva than the pullulan/prednisolone nanofibrous web. The complexation energy calculated using ab initio modeling displayed a more favorable interaction between HPßCD and prednisolone in the case of a molar ratio of 2:1 than 1:1 (CD: drug). Here, the HPßCD/prednisolone IC nanofibrous web has been developed without using a toxic component or solvent to dissolve drug molecules and boost drug loading in amorphous nature. The investigation of IC nanofibrous webs has been conducted to formulate a promising alternative to the orally disintegrating tablet formulation of prednisolone in the market. The nanofibrous structure and the improved physicochemical properties of prednisolone arising with the complexation might ensure a faster disintegration and onset of action against commercially available and orally disintegrating delivery systems during the desired treatment.

Single nozzle electrospinning promoted hierarchical shell wall structured zinc oxide hollow tubes for water remediation.

HYPOTHESIS: Electrospun metal oxide hollow tubes are of great interest owing to their unique structural advantages compared to solid nanofibers. Although intensive research on preparation of hollow tubes have been devoted, formation of hierarchical shells remains a significant challenge. EXPERIMENTS: Herein, we demonstrate the fabrication of highly uniform, reproducible and industrially feasible ZnO hollow tubes (ZHT) with two-level hierarchical shells via a simple and versatile single-nozzle electrospinning strategy coupled with subsequent controlled thermal treatment. FINDINGS: The morphological investigation reveals that the hollow tubes built from nanostructures which has unique surface structure on their wall. The mechanism by which the composite fibers transferred to hollow tubes is primarily based on the evaporation rate of the polymeric template. Notably, tuning the heating rate from 5 °C to 50 °C/min possess adverse effect on formation of hollow tubes, thus subsequently produced ZnO nanoplates (ZNP). The comparative photocatalytic analysis emphasized that ZHT shows higher photocatalytic activity than ZNP. This finding has made an evident that the inherent abundant defects in the electrospun derived nanostructures are not only sufficient for improving the photocatalytic activity. Studies on bacterial growth inhibition showcased a superior bactericidal effect against Staphylococcus aureus and Escherichia coli implying its potentiality for disinfecting the bacteria from water.

Electrospun formulation of acyclovir/cyclodextrin nanofibers for fast-dissolving antiviral drug delivery.

Acyclovir is an effective antiviral drug which suffers from limited water solubility and low bioavailability. However, it is possible to eliminate these limitations by forming inclusion complexes with cyclodextrins. In this study, we have reported the electrospinning of polymer-free and free-standing acyclovir/cyclodextrin nanofibers for the first time. This is a promising approach for developing a fast-dissolving delivery system of an antiviral drug molecule. Here, hydroxypropyl-beta-cyclodextrin (HP-ßCD) was used as both complexation agent and electrospinning matrix. The acyclovir/HP-ßCD system was prepared by incorporating ~7% (w/w) of acyclovir into the highly concentrated aqueous solution of HP-ßCD (180%, w/v). The control sample of acyclovir/polyvinylpyrrolidone (PVP) nanofiber were also generated using ethanol/water (3/1, v/v) solvent system and the same initial acyclovir (7%, w/w) content. Due to the inclusion complexation, acyclovir/HP-ßCD nanofibers provided better encapsulation and so loading efficiency. The loading efficiency of acyclovir/HP-ßCD nanofibers was determined as ~98%, while it was ~66% for acyclovir/PVP nanofibers. It was found that acyclovir/HP-ßCD nanofibers contained some crystalline form of acyclovir. Even so, it showed faster dissolving/release and faster disintegration profiles compared to acyclovir/PVP nanofibers which had higher amount of crystalline acyclovir. The inclusion complexation property and high water solubility of HP-ßCD (> 2000 mg/mL) ensured the fast-dissolving property of acyclovir/HP-ßCD nanofibers. Briefly, acyclovir/HP-ßCD nanofibers are quite promising alternative to the polymeric based system for the purpose of fast-dissolving oral drug delivery. The enhanced physicochemical properties of drug molecules and the use of water during whole process can make drug/cyclodextrin nanofibers a favorable dosage formulation for the desired treatments.

Colon targeted delivery of niclosamide from ß-cyclodextrin inclusion complex incorporated electrospun Eudragit® L100 nanofibers.

Electrospun nanofibers incorporated with inclusion complex (IC) of niclosamide (NIC) and hydroxypropyl-beta-cyclodextrin (HPßCD) (NIC-HPßCD-IC) was produced from pH-responsive polymer (Eudragit® L100, EUD), which disintegrates at pH values higher than 6, (EUD-NIC-HPßCD-IC-NF) for targeted delivery of NIC to the colon. Pristine EUD nanofibers (EUD-NF), only NIC loaded (EUD-NIC-NF) and physical mixture of NIC and HPßCD loaded EUD nanofibers (EUD-NIC-HPßCD-NF) were also produced as reference. SEM images revealed the bead-free and uniform morphology of nanofibers. XRD, TGA, and DSC were also performed for both NIC-HPßCD-IC and electrospun nanofibers and it was seen that there are some NIC molecules, which cannot make IC. Dissolution studies were carried out for 240 min at pH 1.2 and pH 7 simulating stomach and colon, respectively. EUD-NIC-NF released almost 53 % of NIC in 120 min, whereas EUD-NIC-HPßCD-NF (15 %) and EUD-NIC-HPßCD-IC-NF (8 %) released at most 15 % of NIC in 120 min. Then, remained NIC in the nanofibers released into the colon for the next 120 min. The slight difference in the release of NIC into stomach from EUD-NIC-HPßCD-NF and EUD-NIC-HPßCD-IC-NF might be due to the uncomplexed NIC molecules in EUD-NIC-HPßCD-IC-NF. More importantly, EUD-NIC-HPßCD-IC-NF was quite effective for preventing the release of NIC in the stomach in contrast to EUD-NIC-NF, which has already released more than half amount of NIC in 120 min. In conclusion, this study might open new areas for developing targeted delivery systems by the combination of nanofibers and CD-ICs for hydrophobic drugs such as NIC.

Design of polymer-free Vitamin-A acetate/cyclodextrin nanofibrous webs: antioxidant and fast-dissolving properties.

The encapsulation of food/dietary supplements into electrospun cyclodextrin (CD) inclusion complex nanofibers paves the way for developing novel carrying and delivery substances along with orally fast-dissolving properties. In this study, CD inclusion complex nanofibers of Vitamin-A acetate were fabricated from polymer-free aqueous systems by using the electrospinning technique. The hydroxypropylated (HP) CD derivatives of HPßCD and HPγCD were used for both encapsulation of Vitamin-A acetate and the electrospinning of free-standing nanofibrous webs. The ultimate Vitamin-A acetate/CD nanofibrous webs (NWs) were obtained with a loading capacity of 5% (w/w). The amorphous distribution of Vitamin-A acetate in the nanofibrous webs by inclusion complexation and the unique properties of nanofibers (e.g. high surface area and porosity) ensured the fast disintegration and fast dissolution/release of Vitamin-A acetate/CD-NW in a saliva simulation and aqueous medium. The enhanced solubility of Vitamin-A acetate in the case of Vitamin-A acetate/CD-NW also ensured an improved antioxidant property for the Vitamin-A acetate compound. Moreover, Vitamin-A acetate thermally degraded at higher temperature in Vitamin-A acetate/CD-NWs, suggesting the enhanced thermal stability of this active compound. Here, HPßCD formed inclusion complexes in a more favorable way when compared to HPγCD. Therefore, there were some uncomplexed Vitamin-A acetate crystals detected in Vitamin-A acetate/HPγCD-NW, while Vitamin-A acetate molecules loaded in Vitamin-A acetate/HPßCD-NW were completely in complexed and amorphous states. Depending on this, better solubilizing effect, higher release amount and enhanced antioxidant properties have been provided for the Vitamin-A acetate compound in the case of Vitamin-A acetate/HPßCD-NW.

Progress in the design and development of "fast-dissolving" electrospun nanofibers based drug delivery systems - A systematic review.

Electrospinning has emerged as most viable approach for the fabrication of nanofibers with several beneficial features that are essential to various applications ranging from environment to biomedicine. The electrospun nanofiber based drug delivery systems have shown tremendous advancements over the controlled and sustained release complemented from their high surface area, tunable porosity, mechanical endurance, offer compatible environment for drug encapsulation, biocompatibility, high drug loading and tailorable release characteristics. The dosage formulation of poorly water-soluble drugs often faces several challenges including complete dissolution with maximum therapeutic efficiency over a short period of time especially through oral administration. In this context, challenges associated with the dosage formulation of poorly-water soluble drugs can be addressed through combining the beneficial features of electrospun nanofibers. This review describes major developments progressed in the preparation of electrospun nanofibers based "fast dissolving" drug delivery systems by employing variety of polymers, drug molecules and encapsulation approaches with primary focus on oral delivery. Furthermore, the review also highlights current scientific challenges and provide an outlook with regard to future prospectus.

Functionalized Electrospun Nanofibers as a Versatile Platform for Colorimetric Detection of Heavy Metal Ions in Water: A Review.

The increasing heavy metal pollution in the aquatic ecosystem mainly driven by industrial activities has raised severe concerns over human and environmental health that apparently necessitate the design and development of ideal strategies for the effective monitoring of heavy metals. In this regard, colorimetric detection provides excellent opportunities for the easy monitoring of heavy metal ions, and especially, corresponding solid-state sensors enable potential opportunities for their applicability in real-world monitoring. As a result of the significant interest originating from their simplicity, exceptional characteristics, and applicability, the electrospun nanofiber-based colorimetric detection of heavy metal ions has undergone radical developments in the recent decade. This review illustrates the range of various approaches and functional molecules employed in the fabrication of electrospun nanofibers intended for the colorimetric detection of various metal ions in water. We highlight relevant investigations on the fabrication of functionalized electrospun nanofibers encompassing different approaches and functional molecules along with their sensing performance. Furthermore, we discuss upcoming prospectus and future opportunities in the exploration of designing electrospun nanofiber-based colorimetric sensors for real-world applications.

Development of ferulic acid/cyclodextrin inclusion complex nanofibers for fast-dissolving drug delivery system.

Production of electrospun nanofibrous mats of cyclodextrin inclusion complexes with the incorporation of drug molecules would enable promising designing of fast dissolving delivery systems (FDDS) for oral treatments. Here, the single-step electrospinning technique has been applied to prepare cyclodextrin inclusion complex nanofibrous mats (CD-IC NM) of ferulic acid from complete aqueous systems without using any polymeric matrix. The free-standing ferulic acid/CD-IC NM have been electrospun from two different modified cyclodextrin derivatives of hydroxypropyl-beta-cyclodextrin (HP-ß-CD) and hydroxypropyl-gamma-cyclodextrin (HP-γ-CD). The initial content of ferulic acid (1/1 ferulic acid/CD (molar ratio) and ~11% (w/w)) has been protected in case of both ferulic acid/CD-IC NM and so the electrospun nanofibrous mats have been fabricated by the ~100% loading efficiency. It has been detected from the in vitro release and disintegration tests that, the amorphous state of ferulic acid based on inclusion complex formation, and the highly porous feature and high surface area of nanofibrous mats have ensured the fast dissolution/release of ferulic acid and disintegration of nanofibrous mats into the liquid medium and artificial saliva. Herein, HP-γ-CD has formed inclusion complexes with ferulic acid more favorably than HP-ß-CD and this has leaded to the existence of some un-complexed ferulic acid crystals in ferulic acid/HP-ß-CD-IC NM while, ferulic acid has been completely complexed and is in amorphous state in ferulic acid/HP-γ-CD-IC NM. Furthermore, the thermal stability of ferulic acid has been enhanced as an inclusion complexation aid observed by the shift of thermal degradation temperature of ferulic acid from the range of ~120-200 °C to ~140-280 °C.

Antioxidant, antibacterial and antifungal electrospun nanofibers for food packaging applications.

Food packaging is a multidisciplinary area that encompasses food science and engineering, microbiology, as well as chemistry, and ignited tremendous interest in maintaining the freshness and quality of foods and their raw materials from oxidation and microbial spoilage. With the advances in the packaging industry, they could be engineered as easy-to-open, resealable, active, as well as intelligent with the incorporation of sensory elements while offering desired barrier properties against oxygen and water vapor. In this regard, the use of the electrospinning approach allows producing nanofibrous packaging materials with large surface-to-volume ratios and enables the higher loading of active agents into packaging materials. Electrospun packaging materials have been produced from various polymers (i.e., synthetic and natural) and their (nano)composites, and were mainly exploited for the encapsulation of active agents for their use as active food packaging materials. The electrospinning process was also used for the deposition of electrospun fibers on films to enhance their performance (e.g., as reinforcement material, or to enhance barrier properties). They could be even engineered to provide nutraceuticals to food, or antioxidant, antimicrobial or antifungal protection to the packaged food. In this article, first, introductory descriptions of food packaging, barrier properties, and electrospinning are given. Afterward, active and intelligent food packaging materials are briefly discussed, and the use of electrospinning for the fabrication of active food packaging materials is elaborated. Particular interest has been given to the polymer-type used in the production of electrospun fibers and active properties of the resultant packaging materials (e.g., antioxidant, antibacterial, antifungal). Finally, this review paper concludes with a summary and future outlook towards the development of electrospun food packaging materials.

Fast-dissolving antioxidant curcumin/cyclodextrin inclusion complex electrospun nanofibrous webs.

Curcumin/Hydroxypropyl-beta-Cyclodextrin (HP-ß-CyD) and Curcumin/Hydroxypropyl-gamma-Cyclodextrin (HP-γ-CyD) inclusion complex nanofibrous webs were produced using electrospinning technique for the purpose of orally fast-dissolving antioxidant food supplement. Curcumin was totally preserved without any loss during the electrospinning process. The aqueous solutions of curcumin/HP-ß-CyD and curcumin/HP-γ-CyD were yielded uniform fiber morphology with ~200 nm and ~900 nm average fiber diameter, respectively. Both Curcumin/CyD webs were produced in the form of free-standing and flexible character. Curcumin is a natural bioactive compound with poor water-solubility, however, the phase solubility test and dissolution/disintegration tests (water and artificial saliva) revealed that the water-solubility of curcumin was prominently improved by inclusion complexation with CyD. The antioxidant effect of curcumin in Curcumin/CyD webs was also enhanced due to higher solubility of curcumin by CyD inclusion complex. The results showed that HP-γ-CyD is significantly more effective than HP-ß-CyD in order to enhance the solubility and antioxidant property of curcumin in Curcumin/CyD webs.

Hydrocortisone/cyclodextrin complex electrospun nanofibers for a fast-dissolving oral drug delivery system.

The electrospinning of hydrocortisone/cyclodextrin complex nanofibers was performed in order to develop a fast-dissolving oral drug delivery system. Hydrocortisone is a water-insoluble hydrophobic drug, yet, the water solubility of hydrocortisone was significantly enhanced by inclusion complexation with hydroxypropyl-beta-cyclodextrin (HP-ß-CyD). In this study, hydrocortisone/HP-ß-CyD complexes were prepared in aqueous solutions having molar ratios of 1/1, 1/1.5 and 1/2 (hydrocortisone/HP-ß-CyD). Highly concentrated aqueous solutions of HP-ß-CyD (180%, w/v) were used for hydrocortisone/HP-ß-CyD systems (1/1, 1/1.5 and 1/2) in order to perform electrospinning without the use of an additional polymer matrix. The turbidity of hydrocortisone/HP-ß-CyD (1/1 and 1/1.5) aqueous solutions indicated the presence of some uncomplexed crystals of hydrocortisone whereas the aqueous solution of hydrocortisone/HP-ß-CyD (1/2) was homogeneous indicating that hydrocortisone becomes totally water-soluble by inclusion complexation with HP-ß-CyD. Nonetheless, the electrospinning of hydrocortisone/HP-ß-CyD systems (1/1, 1/1.5 and 1/2) successfully yielded defect-free uniform nanofibrous structures. Moreover, the electrospinning process was quite efficient that hydrocortisone was completely preserved without any loss yielding hydrocortisone/HP-ß-CyD nanofibers having the initial molar ratios (1/1, 1/1.5 and 1/2). The structural and thermal characterization of the hydrocortisone/HP-ß-CyD nanofibers revealed that hydrocortisone was totally inclusion complexed with HP-ß-CyD and was in the amorphous state in hydrocortisone/HP-ß-CyD (1/2) nanofibers whereas some uncomplexed crystalline hydrocortisone was present in hydrocortisone/HP-ß-CyD (1/1 and 1/1.5) nanofibers. Nevertheless, hydrocortisone/HP-ß-CyD (1/1, 1/1.5 and 1/2) complex aqueous systems were electrospun in the form of nanofibrous webs having a free-standing and flexible nature. The hydrocortisone/HP-ß-CyD (1/1, 1/1.5 and 1/2) nanofibrous webs have shown fast-dissolving behavior in water or when they were in contact with artificial saliva. Yet, the hydrocortisone/HP-ß-CyD (1/2) nanofibrous web dissolved more quickly than the hydrocortisone/HP-ß-CyD (1/1 and 1/1.5) nanofibrous webs due to the full inclusion complexation and the amorphous state of hydrocortisone in this sample. In short, the results suggest that polymer-free electrospun nanofibrous webs produced from hydrocortisone/HP-ß-CyD could be quite applicable for fast-dissolving oral drug delivery systems.

Highly selective surface adsorption-induced efficient photodegradation of cationic dyes on hierarchical ZnO nanorod-decorated hydrolyzed PIM-1 nanofibrous webs.

Selectivity of catalysts toward harmful cationic pollutants in industrial wastewater remains challenging but is of crucial importance in environmental remediation processes. Here, we present a complex network of a hydrolyzed polymer of intrinsic microporosity (HPIM)-based electrospun nanofibrous web with surface functional decoration of ZnO nanorods (NRs) as a hierarchical platform for selective and rapid degradation of cationic dyes. Over a single species or binary mixtures, cationic dyes were selectively adsorbed by the HPIM surface, which then rapidly degraded under simultaneous photoirradiation through the ZnO NRs. Both HPIM and ZnO exhibited high electronegative surfaces, which induced the selectivity towards the cationic dyes and rapidly degraded the pollutants with the production of reactive oxygen species under photoirradiation. Further, as a free-standing web, the catalytic network could be easily separated and reused without any significant loss of catalytic activity after multiple cycles of use. The hierarchical platform of ZnO/HPIM-based heterostructures could be a promising catalytic template for selective degradation of synthetic dyes in mixed wastewater samples.