Browsing by Author "Chang, Ming-Wei"
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Item Open Access 3D Electrohydrodynamic Printing of Highly Aligned Dual-Core Graphene Composite Matrices(Elsevier, 2019-07-09) Ahmad, Zeeshan; Wang, Baolin; Chen, Xing; Huang, Jie; Chang, Ming-WeiThe aim of this study was to develop an EHD printing method to fabricate graphene-loaded polycaprolactone (PCL)/polyethylene oxide (PEO) dual-core matrices. Graphene was incorporated in shell PCL components, while gelatin and dopamine hydrochloride (DAH) were encapsulated in two PEO cores to enhance biocompatibility of graphene-loaded matrices. Furthermore, the effect of PEO concentration on dual-core fiber formation was evaluated. The influence of process parameters (applied voltage, inner flow rate, outer flow rate and X-Y-Z collector stage speed) on dual-core fiber morphology was evaluated. Our findings show graphene-loaded structures to possess two inner cores and increasing graphene content yields matrices with smoother surfaces, causing a slight reduction in their contact angle behavior. Furthermore, the addition of graphene to matrices results in reduced elasticity. DAH release from matrices comprising various graphene concentrations showed no significant difference and drug release mechanism was diffusion based. In vitro biological tests indicate resulting graphene-loaded dual-core matrices exhibit good biocompatibility and also improve PC12 cell migration. The findings suggest matrices to have potential applications in nerve restoration and regeneration.Item Open Access Approaches in topical ocular drug delivery and developments in the use of contact lenses as drug-delivery devices(Future Science Ltd, 2017-06-21) Mehta, P.; Haj-Ahmad, R.; Al-Kinani, Ali; Arshad, Muhammad Sohail; Chang, Ming-Wei; Alany, Raid G.; Ahmad, Z.Drug-delivery approaches have diversified over the last two decades with the emergence of nanotechnologies, smart polymeric systems and multimodal functionalities. The intended target for specific treatment of disease is the key defining developing parameter. One such area which has undergone significant advancements relates to ocular delivery. This has been expedited by the development of material advancement, mechanistic concepts and through the deployment of advanced process technologies. This review will focus on the developments within lens-based drug delivery while touching on conventional and current methods of topical ocular drug delivery. A summary table will provide quick reference to note the key findings in this area. In addition, the review also elucidates current theranostic and diagnostic approaches based on ocular lenses.Item Open Access Assessing the ex vivo permeation behaviour of functionalised contact lens coatings engineered using an electrohydrodynamic technique(IOP, 2018-11-20) Ahmad, Z.; Alany, Raid G.; Amoaku, W. M.; Chang, Ming-Wei; Alqahtani, Ali; Arshad, Muhammad Sohail; Qutachi, Omar; Al-Kinani, Ali A.; Mehta, P.In vitro testing alone is no longer considered sufficient evidence presented solely with respect to drug release and permeation testing. These studies are thought to be more reliable and representative when using tissue or animal models; as opposed to synthetic membranes. The release of anti-glaucoma drug timolol from electrically atomised coatings was assessed here using freshly excised bovine corneal tissue. Electrohydrodynamic processing was utilised to engineer functionalised fibrous polyvinylpyrrolidone (PVP)-Poly (N-isopropylacrylamide) (PNIPAM) coatings or the outer side of commercial silicone contact lenses. Benzalkonium chloride (BAC), ethylenediaminetetraacetic acid (EDTA), Brij® 78 and borneol were employed as permeation enhancers to see their effect on ex vivo permeation of timolol maleate through the cornea. Formulations containing permeation enhancers showed a vast improvement with respect to cumulative amount of drug permeating through the cornea as shown by a 6 fold decrease in lag time compared to enhancer-free formulations. Most drug delivery systems require the drug to pass or permeate through a tissue or biological membrane. This study has shown that to fully appreciate and understand how a novel drug delivery system will behave not only within the device but with the external environment or tissue, it is imperative to have in vitro and ex vivo data in conjunction.Item Open Access Co-Printing of Vertical Axis Aligned Micron-Scaled Filaments Via Simultaneous Dual Needle Electrohydrodynamic Printing(Elsevier, 2018-05-08) Wang, Baolin; Wu, Shuting; Ahmad, Z.; Li, Jing-Song; Chang, Ming-WeiIn this study dual-needle electrohydrodynamic co-printing (DN-EHDCP) was developed to fabricate unique micron-scaled architectures based on multi-material fibrous (filamentous) morphologies. Two stainless steel needles (contributing towards dual needle design) were used to simultaneously co-print poly(ɛ-caprolactone) (PCL) and polyvinylpyrrolidone (PVP) polymers (using solvent based formulations including Fe 3 O 4 nano- particles and active pharmaceutical ingredient (API). Differences in polymer hydrophobicity and dissolution rate were used to modulate drug release (tetracycline hydrochloride, TE-HCL) from various co-printed configura- tions. Optical, scanning electron and fluorescent microscopy confirmed precision alignment and vertical stacking of both PVP and PCL printed fi laments. Process parameters were found to strongly influence co-print construct diameter. Fourier Transform Infrared (FTIR) spectroscopy confirmed spatial locations of both PVP and PCL filaments. TE-HCL release from co-printed formulations exhibited two phases; rapid and sustained. In vitro biological assay (using L929 cell lines) demonstrated construct biocompatibility. However, selective integration (spatial and quantity) of sacrificial PVP fibers (after rapid dissolution) provided a method of in situ void en- gineering for enhanced interfacial interaction for remaining PCL structures. The present study shows the de- velopment and use of simultaneously co-printed filaments in the vertical axis with potential to control drug release through alignment of individual filaments and material type. Furthermore, the use of composite matrix under an external stimulus is also demonstrated indicating multiple approaches to modulate API releaseItem Open Access Controlled Engineering of Highly Aligned Fibrous Dosage Form Matrices for Controlled Release(Elsevier, 2018-08-20) Wu, Shuting; Ahmad, Z.; Li, Jing-Song; Chang, Ming-WeiIn this study, complex drug-cellulose acetate (CA) composite films were designed and fabricated possessing pre-determined grid spacing for inter-connected fibrous films. Ibuprofen (IBU) was selected as the active ingredient. and grid spacing was varied between 300 to 500μm (fiber diameter~35μm) for various geometries. Process parameter impact on fiber morphology and deposition was investigated. FTIR confirmed IBU encapsulation and XRD analysis indicated the drug was dispersed (amorphous) in films. Inter-connected grid void geometry was shown to impact water contact behavior, and drug release mechanism was shown to be Fickian diffusion. Furthermore, drug release rate depended on geometry of engineered structures. The findings suggest a spatial design approach for modulated drug release from bespoke drug delivery dosage forms.Item Metadata only Controlled Morphing of Microbubbles to Beaded Nanofibers via Electrically Forced Thin Film Stretching(MDPI, 2017-07-03) Yao, Zhi-Cheng; Yuan, Qiantailang; Ahmad, Z.; Huang, Jie; Li, Jing-Song; Chang, Ming-WeiTopography and microstructure engineering are rapidly evolving areas of importance for biomedical and pharmaceutical remits. Here, PVA (Polyvinyl alcohol) microbubbles (diameter range ~126 to 414 μm) were used to fabricate beaded (beads-on) nanofibers using an electrohydrodynamic atomization (EHDA) technique. Mean fiber diameter, inter-bead distance, and aspect ratio (AR) were investigated by regulating EHDA process parameters. PVA fibers (diameter range ~233 to 737 nm) were obtained possessing bead ARs in the range of ~10 to 56%. AR was used to modulate hydrophilicity and active release.Item Open Access Designer fibers from 2D to 3D – Simultaneous and controlled engineering of morphology, shape and size(Elsevier, 2017-10-09) Yao, Zhi-Cheng; Zhang, Chunchen; Ahmad, Z.; Huang, Jie; Li, Jing-Song; Chang, Ming-WeiTopography and surface morphology of micrometer and nanometer scaled fibrous biomaterials are crucial for bioactive component encapsulation, release, promoting cell proliferation and interaction within biological environment. Specifically, for drug delivery and tissue repair applications, surface engineering provides control on both aspects in tandem. In this study, the bioactive component (ganoderma lucidum spore polysaccharide (GLSP)) was loaded into zein prolamine (ZP) fiber matrices via coaxial electrospinning (CES) technique. During the CES process, various outer layer enveloping fluids were used to modulate fiber topography in-situ (from 2D to 3D). SEM and water contact angle tests indicate enveloping media impact electrospun fiber diameter (ranging from 400 nm to 3.0 μm) and morphologies (from flat ribbon-like to solid cylindrical structures), with the latter impacting GLSP release profile. Furthermore, CCK-8 assay assessment indicates fibroblast cell proliferation (L929 cell line), while cell extension was also observed for modified ZP fibers. The results demonstrate potential applications of modified fiber morphologies, which are tailored in-situ without impacting chemical stability and encapsulation.Item Open Access Development and characterisation of electrospun timolol maleate-loaded polymeric contact lens coatings containing various permeation enhancers(Elsevier, 2017-09-14) Mehta, P.; Al-Kinani, Ali A.; Arshad, Muhammad Sohail; Chang, Ming-Wei; Alany, Raid G.; Ahmad, Z.Despite exponential growth in research relating to sustained and controlled ocular drug delivery; anatomical and chemical barriers of the eye still pose formulation challenges. Nanotechnology integration into the pharmaceutical industry has aided efforts in potential ocular drug device development. Here, the integration and in vitro effect of four different permeation enhancers (PEs) on the release of anti-glaucoma drug timolol maleate (TM) from polymeric nanofiber formulations is explored. Electrohydrodynamic (EHD) engineering, more specifically electrospinning, was used to engineer nanofibers (NFs) which coated the exterior of contact lenses. Parameters used for engineering included flow rates ranging from 8 to 15 μL/min and a novel EHD deposition system was used; capable of hosting four lenses, masked template and a ground electrode to direct charged atomised structures. SEM analysis of the electrospun structures confirmed the presence of smooth nano-fibers; whilst thermal analysis confirmed the stability of all formulations. In vitro release studies demonstrated a triphasic release; initial burst release with two subsequent sustained release phases with most of the drug being released after 24 hours (86.7%) Biological evaluation studies confirmed the tolerability of all formulations tested with release kinetics modelling results showing drug release was via quasi-Fickian or Fickian diffusion. There were evident differences (p < 0.05) in TM release dependant on permeation enhancer.Item Metadata only Development of hybrid 3D-printed structure with aligned drug-loaded fibres using in-situ custom designed templates(Elsevier, 2023-09-07) Muldoon, Kirsty; Feng, Yu; Dooher, Thomas; O'Connor, Caolan; Wang, Baolin; Wang, Hui-Min David; Ahmad, Zeeshan; McLaughlin, James; Chang, Ming-WeiFibre alignment technology is crucial in various emerging applications, such as drug delivery systems, tissue engineering, and scaffold fabrication. However, conventional methods have limitations when it comes to incorporating aligned fibres into 3D printed structures in situ. This research demonstrates the use of custom-designed templates made with conductive ink to control the alignment of drug-loaded polymer fibres on a 3D printed microscale structure. Three different geometries were designed, and the effects of the template on fibre diameter and pattern were investigated. The hybrid structure demonstrated successful control of aligned fibres on printed structures using grounded conductive ink geometric electrodes, as confirmed by SEM. All three custom-designed templates presented unique geometric alignments and fibre diameters of around 1 μm. Additionally, the different collector shapes had an impact on the distribution of fibre diameters. FTIR and EDX analyses concluded that the drug was effectively encapsulated throughout the fibres. In-situ deposition of fibres onto the 3D printed structure enhanced the mechanical properties, and water contact angle results showed that the hybrid structure transitioned to a hydrophilic state with the addition of fibres. A drug delivery study confirmed that the hybrid structure functions as a steady release system, following a Korsmeyer-Peppas kinetic release model. TGA results indicated that the samples are thermally stable, and DSC analysis concluded that the samples were homogeneously produced. The results obtained from the hybrid structures provide a novel mechanism for integrating aligned fibres and 3D printed structures for development in fields such as biomedical engineering, regenerative medicine, and advanced manufacturing.Item Open Access Development of Random and Ordered Composite Fiber Hybrid Technologies for Controlled Release Functions(Elsevier, 2018-03-06) Wang, Baolin; Ahmad, Z.; Huang, J.; Li, Jing-Song; Chang, Ming-WeiFibrous technologies (such as membranes, films, patches and filters) and their enabling engineering platforms have gained considerable interest over the last decade. In this study, novel fibrous constructs from a unique engineering platform were developed based on hybrid electrohydrodynamic (EHD) technology; incorporating functional and bioactive materials within random and aligned fibrous formulation geometries. Complex constructs were engineered using 3D printing (polycaprolactone, PCL, for sustained delivery) and electrospinning (polyvinylpyrolidone, PVP, for rapid release) in an intercalating material layer-by-layer format using a side-by-side technological approach. Here, structure generation proceeded with deposition of ordered PCL fibers enabling well-defined void size and overall dimension, after which randomly spun PVP fibers formed a construct overcoat (as a membrane). Differences between polymer dissolution rate, hydrophilicity, mechanical properties and functional material hosting (and linked external auxiliary magnetic field trigger) provided opportunities to modulate antibiotic drug (tetracycline hydrochloride, TE-HCL) release. In vitro cell studies using human umbilical vein blood vessel cell line demonstrated device biocompatibility and Escherichia Coli (E. coli) was selected to demonstrate anti-bacterial function. Overall, a new hybrid engineering platform to prepare customizable and exciting multi-faceted drug release constructs is elucidated.Item Open Access Dual Rotation Centrifugal Electrospinning: A Novel Approach to Engineer Multi-Directional and Layered Fiber Composite Matrices(Springer, 2018-10-19) Wang, Li; Wang, Baolin; Ahmad, Z.; Li, Jing-Song; Chang, Ming-WeiIn this study, a dual rotation centrifugal electrospinning system (DRCES) is designed, developed and used to prepare medicated fabrics. Through simultaneous rotation of both spinneret and collector; multi-directional blended fiber matrices (PVP and TPU) were deposited directly on the rotating collector. To detail the process, key stages of the centrifugal electrospinning process are elaborated, and the influence of gas infusion and collector rotation speed on resulting fiber morphologies were explored. Multi-directional fibrous structures show in vitro biocompatibility (fibroblast). Regulation of drug release rate was achieved using polymer composition and filament alignment. This study demonstrates a rapid fabrication method (~ 50 g/h) to engineer layered fibrous structures using DRCES; which provides a foundation for preparing complex drug matrices (single and multi–directional) for tailored active component release.Item Open Access Elastic Anti-Bacterial Membranes Comprising Particulate Laden Fibers for Wound Healing Applications(Elsevier, 2018-10-04) Lia, Yudong; Zhang, Chunchen; Zhu, Li-Fang; Ahmad, Z.; Li, Jing-Song; Chang, Ming-WeiMedicated skin care products are available in various forms; ranging from lotions and creams to bandages and membranes. In this study, anti-bacterial particulate laden fibrous membranes were prepared via electrospraying of tetracycline hydrochloride (TE-HCL) loaded poly(ε-caprolactone) (PCL) particles alongside electrospinning of thermoplastic polyurethane (TPU) fibers, through which both mechanical and biological aspects of a complete membrane system can be achieved. Random (R) and ordered (P and V) patterns of TPU fibrous membranes (FMs) were afforded using a rotating collector. Water contact angle and bacterial inhibition zone tests were performed to assess suitability of the system specifically for wound care. Stress-strain and in-vitro drug release tests were performed to assess suitability of newly developed systems specifically for hybrid membranes (HMs). The highest tensile strength (32.1 ± 4.9 MPa) with elasticity (104.2 ± 6.0 %) and the most sustained release rate indicate HMs (P) are potentially suitable materials for wound care applications.Item Open Access Electrically atomised formulations of timolol maleate for direct and on-demand ocular lens coatings(Elsevier, 2017-06-15) Mehta, P.; Al-Kinani, Ali A.; Haj-Ahmad, R.; Arshad, Muhammad Sohail; Chang, Ming-Wei; Alany, Raid G.; Ahmad, Z.Item Open Access Electrohydrodynamic atomisation driven design and engineering of opportunistic particulate systems for applications in drug delivery, therapeutics and pharmaceutics(Elsevier, 2021-05-04) Zaman, Aliyah; Sayed, Elshaimaa; Evans, David; Morgan, Stuart; Samwell, Chris; Hall, John; Arshad, Muhammad Sohail; Qutachi, Omar; Chang, Ming-Wei; Ahmad, Zeeshan; Simgh, Neenu; Ali, AmnaElectrohydrodynamic atomisation (EHDA) technologies have evolved significantly over the past decade; branching into several established and emerging healthcare remits through timely advances in the engineering sciences and tailored conceptual process designs. More specifically for pharmaceutical and drug delivery spheres, electrospraying (ES) has presented itself as a high value technique enabling a plethora of different particulate structures. However, when coupled with novel formulations (e.g. co-flows) and innovative device aspects (e.g., materials and dimensions), core characteristics of particulates are manipulated and engineered specifically to deliver an application driven need, which is currently lacking, ranging from imaging and targeted delivery to controlled release and sensing. This demonstrates the holistic nature of these emerging technologies; which is often overlooked. Parametric driven control during particle engineering via the ES method yields opportunistic properties when compared to conventional methods, albeit at ambient conditions (e.g., temperature and pressure), making this extremely valuable for sensitive biologics and molecules of interest. Furthermore, several processing (e.g., flow rate, applied voltage and working distance) and solution (e.g., polymer concentration, electrical conductivity and surface tension) parameters impact ES modes and greatly influence the production of resulting particles. The formation of a steady cone-jet and subsequent atomisation during ES fabricates particles demonstrating monodispersity (or near monodispersed), narrow particle size distributions and smooth or textured morphologies; all of which are successfully incorporated in a one-step process. By following a controlled ES regime, tailored particles with various intricate structures (hollow microspheres, nanocups, Janus and cell-mimicking nanoparticles) can also be engineered through process head modifications central to the ES technique (single-needle spraying, coaxial, multi-needle and needleless approaches). Thus, intricate formulation design, set-up and combinatorial engineering of the EHDA process delivers particulate structures with a multitude of applications in tissue engineering, theranostics, bioresponsive systems as well as drug dosage forms for specific delivery to diseased or target tissues. This advanced technology has great potential to be implemented commercially, particularly on the industrial scale for several unmet pharmaceutical and medical challenges and needs. This review focuses on key seminal developments, ending with future perspectives addressing obstacles that need to be addressed for future advancement.Item Open Access Electrosprayed mesoporous particles for improved aqueous solubility of a poorly water soluble anticancer agent: in vitro and ex vivo evaluation(Elsevier, 2018-03-30) Ahmad, Z.; Sayed, E.; Karavasili, Chirstina; Ruparelia, K. C.; Haj-Ahmad, R.; Charalambopoulou, G; Giasafaki, D.; Cox, Paul; Singh, Neenu; Giassafaki, Lefki-Pavlina N.; Mpenekou, A.; Steriotis, T.; Markopoulou, C. K.; Vizirianakis, I. S.; Chang, Ming-Wei; Fatoutos, D. G.Encapsulation of poorly water-soluble drugs into mesoporous materials (e.g. silica) has evolved as a favorable strategy to improve drug solubility and bioavailability. Several techniques (e.g. spray drying, solvent evaporation, microwave irradiation) have been utilized for the encapsulation of active pharmaceutical ingredients (APIs) into inorganic porous matrices. In the present work, a novel chalcone (KAZ3) with anticancer properties was successfully synthesized by Claisen-Schmidt condensation. KAZ3 was loaded into mesoporous (SBA-15 and MCM-41) and non-porous (fumed silica, FS) materials via two techniques; electrohydrodynamic atomization (EHDA) and solvent impregnation. The effect of both loading methods on the physicochemical properties of the particles (e.g. size, charge, entrapment efficiency, crystallinity, dissolution and permeability) was investigated. Results indicated that EHDA technique can load the active in a complete amorphous form within the pores of the silica particles. In contrast, reduced crystallinity (~79%) was obtained for the solvent impregnated formulations. EHDA engineered formulations significantly improved drug dissolution up to 30-fold, compared to the crystalline drug. Ex vivo studies showed EHDA formulations to exhibit higher permeability across rat intestine than their solvent impregnated counterparts. Cytocompatibility studies on Caco-2 cells demonstrated moderate toxicity at high concentrations of the anticancer agent. The findings of the present study clearly show the immense potential of EHDA as a loading technique for mesoporous materials to produce poorly water-soluble API carriers of high payload at ambient conditions. Furthermore, the scale up potential in EHDA technologies indicate a viable route to enhance drug encapsulation and dissolution rate of loaded porous inorganic materials.Item Open Access Engineering and development of chitosan-based Nanocoatings for Ocular Contact Lenses(2018-12-01) Mehta, P.; Al-Kinani, Ali A.; Arshad, Muhammad Sohail; Singh, Neenu; van der Merwe, Susanna M.; Chang, Ming-Wei; Alany, Raid G.; Ahmad, Z.The research manuscript reports on Electrohydrodynamic Atomisation (EHDA) to engineer on-demand novel coatings for ocular contact lenses. A formulation approach was adopted to modulate the release of timolol maleate (TM) using chitosan and borneol. Polymers polyvinylpyrrolidone (PVP) and poly (N-isopropylacrylamide) (PNIPAM) were utilised to encapsulate TM and were electrically atomised to produce optimised, stationary contact lens coatings. The particle and fibre diameter, thermal stability, material compatibility of the formed coatings along with their in vitro release-modulating effect and ocular tolerability were investigated. The results demonstrated highly stable nano-matrices with advantageous morphology and size. All formulations yielded coatings with high TM encapsulation (>88%); with excellent ocular biocompatibility. The coatings presented biphasic and triphasic release profiles; depending on composition. Kinetic modelling revealed a noticeable effect of chitosan; the higher the concentration, the more the release of TM due to chitosan swelling; with the release mechanism changing from Fickian diffusion (1% w/v; n = 0.5) to non-Fickian (5% w/v, 0.45 < n < 0.89). The use of EHDA has not yet been explored in depth within the ocular research remit; engineering on demand lens coatings capable of sustaining TM release. This is likely to offer an alternative dosage form for management of glaucoma with particular emphasis on improving poor patient compliance.Item Embargo Engineering of tetanus toxoid-loaded polymeric microneedle patches(Springer, 2022-11-17) Arshad, Muhammad Sohail; Gulfam, Shafaq; Zafar, Saman; Jalil, Najmusama Abdul; Ahmad, Nadia; Qutachi, Omar; Chang, Ming-Wei; Singh, Neenu; Ahmad, ZeeshanThis study is aimed to fabricate tetanus toxoid laden microneedle patches by using a polymeric blend comprising of polyvinyl pyrrolidone and sodium carboxymethyl cellulose as base materials and sorbitol as a plasticizer. The tetanus toxoid was mixed with polymeric blend and patches were prepared by using vacuum micromolding technique. Microneedle patches were evaluated for physical attributes such as uniformity of thickness, folding endurance, and swelling profile. Morphological features were assessed by optical and scanning electron microscopy. In vitro performance of fabricated patches was studied by using bicinchoninic acid assay (BCA). Insertion ability of microstructures was studied in vitro on model skin parafilm and in vivo in albino rat. In vivo immunogenic activity of the formulation was assessed by recording immunoglobulin G (IgG) levels, interferon gamma (IFN-γ) levels, and T-cell (CD4+ and CD8+) count following the application of dosage forms. Prepared patches, displaying sharp-tipped and smooth-surfaced microstructures, remained intact after 350 ± 36 foldings. Optimized microneedle patch formulation showed ~ 74% swelling and ~ 85.6% vaccine release within an hour. The microneedles successfully pierced parafilm. Histological examination of microneedle-treated rat skin confirmed disruption of epidermis without damaging the underneath vasculature. A significant increase in IgG levels (~ 21%), IFN-γ levels (~ 30%), CD4+ (~ 41.5%), and CD8+ (~ 48.5%) cell count was observed in tetanus vaccine-loaded microneedle patches treated albino rats with respect to control (untreated) group at 42nd day of immunization. In conclusion, tetanus toxoid-loaded microneedle patches can be considered as an efficient choice for transdermal delivery of vaccine without inducing pain commonly experienced with hypodermic needles.Item Open Access Essential Oil Bioactive Fibrous Membranes Prepared via Coaxial Electrospinning(wiley, 2017-06-07) Yao, Zhi-Cheng; Chen, Si-Cong; Ahmad, Z.; Huang, Jie; Chang, Ming-Wei; Li, Jing-SongA novel antimicrobial composite material was prepared by encapsulating orange essential oil (OEO) in zein prolamine (ZP) via the coaxial electrospinning (ES) technique. By manipulating process parameters, the morphological features of ZP/OEO fibers were modulated. Fine fibers with diameters ranging from 0.7 to 2.3 μm were obtained by regulating ZP solution concentration and process parameters during the ES process. Optimal loading capacity (LC) and encapsulation efficiency (EE) of OEO in fibrous ZP mats were determined to be 22.28% and 53.68%, respectively, and were achieved using a 35 w/v% ZP ES solution. The encapsulation of OEO was found to be reliant on ZP solution concentration (the enveloping medium). SEM analysis indicates the surface morphology of ZP/OEO electrospun fibers is dependent on ZP solution loading volume, with lower ZP concentrations yielding defective fibrous structures (for example, beaded and spindled-string like morphologies). Furthermore, this loading volume also influences OEO LC, EE, mat water contact angle and oil retention. CCK-8 assay and cell morphology assessment (HEK293T cells) indicate no significant change with electrospun ZP and ZP/OEO fibrous membranes over an 8 h period. Antimicrobial activity assessment using Escherichia coli, suggests composite nonwovens possess sterilization properties; elucidating potential application in active food packaging, food preservation and therefore sustainability.Item Open Access Fabrication of Stacked-Ring Netted Tubular Constructs Via 3D-Template Electrohydrodynamic Printing(Springer, 2018-05-24) Wang, Li; Luo, Y.; Ahmad, Z.; Li, Jing-Song; Chang, Ming-WeiElectrohydrodynamic (EHD) printing is an emerging additive manufacturing process which provides several opportunities for advanced fiber patterning and alignment. In this study, stacked-ring netted tubular constructs were printed using controlled EHD fiber deposition. To achieve this, a modified EHD system was developed which integrated air and heating moduli, in addition to a 3D cylindrical collector. The impact of additional peripheral components was evident through enhanced solidification of as-formed polycaprolactone (PCL) polymer fiber prints, which further enabled fabrication of stacked PCL fiber rings. Subsequently, stacked-ring netted tubular constructs (via x-axis deposition manipulation) were fabricated. Electric-field simulations were used to elucidate construct formation mechanism. The modified printing system provides much needed control on fiber deposition and solidification; enabling integration of essential bio-interface features and morphologies (e.g. tissue structure and surface mimicry) for advanced 3D biomaterial engineering.Item Open Access Fibrous polymeric buccal film formulation, engineering and bio-interface assessment(Elsevier, 2017-10-03) Nazari, K.; Kontogiannidou, Eleni; Haj-Ahmad, R.; Andreadis, Dimitrios; Rasekh, M.; Bouropoulos, Nikolaos; van der Merwe, Susanna M.; Chang, Ming-Wei; Fatouros, Dimitrios; Ahmad, Z.Polymer based dosages form the mainstay of drug delivery systems either as simple matrix carrier materials or active release behavior modulating agents. In addition, several techniques have been developed further to deliver novel polymeric structures. One such method is electrospinning (ES); a maturing process which is operational at the ambient environment and enables drug loading (in molecularly dispersed form) directly into a fibrous polymer matrix system. Since there is an impending need to address healthcare challenges arising from an increase in the aging population (requiring enhanced treatments), the ES method was used to develop fibrous polymer composite-indomethacin (INDO) films for potential use in the buccal region. Films were assessed for their inter-facial behavior at bio-interfaces (in-vitro and ex-vivo). Polymeric excipients possessing an established profile for commercial dosage form development were selected. Fibrous films (all fibre components <400 nm) were characterised using DSC, TGA, FTIR, Raman and XRD. DSC and XRD demonstrated INDO change from crystalline to amorphous state. FTIR and Raman data suggest INDO, PVP and co-polymers (Methocel™ E5, Methocel™ E15 and Tween® 80) were integrated in stable fashion into filamentous structures via ES. Variable INDO release behavior from several matrices was observed suggesting a potential route to tailor drug release based on polymeric excipient use and ratio. Furthermore, permeation studies using a porcine buccal model demonstrated sustained permeation once dosages are attached to the buccal mucosa. The insoluble nature of cellulose excipients were used to promote sustained release while the use of Tween® 80 surfactant was used to enhance permeation of INDO through polymer interaction with excised tissue. Finally, histology studies indicate polymer excipient selection impacts the bio-interface. In summary, a facile approach to formulate, encapsulate and engineer fibrous polymeric buccal films (on demand) is shown. The method enables drug dispersion directly within the composite polymeric system, which has a clear impact on drug release, in-vitro and ex-vivo bio-interaction.