Browsing by Author "Ahmad, Zeeshan"

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    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-Wei
    The 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.
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    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-Wei
    Fibre 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.
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    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, Amna
    Electrohydrodynamic 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.
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    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, Zeeshan
    This 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.
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    Influence of Critical Parameters on Cytotoxicity Induced by Mesoporous Silica Nanoparticles
    (MDPI, 2022-06-11) Amirsadra, Ahmadi; Sokunbi, Moses; Patel, Trisha; Ahmad, Zeeshan; Singh, Neenu
    Mesoporous Silica Nanoparticles (MSNs) have received increasing attention in biomedical applications due to their tuneable pore size, surface area, size, surface chemistry, and thermal stability. The biocompatibility of MSNs, although generally believed to be satisfactory, is unclear. Physicochemical properties of MSNs, such as diameter size, morphology, and surface charge, control their biological interactions and toxicity. Experimental conditions also play an essential role in influencing toxicological results. Therefore, the present study includes studies from the last five years to statistically analyse the effect of various physicochemical features on MSN-induced in-vitro cytotoxicity profiles. Due to non-normally distributed data and the presence of outliers, a Kruskal-Wallis H test was conducted on different physicochemical characteristics, including diameter sizes, zeta-potential measurements, and functionalisation of MSNs, based on the viability results, and statistical differences were obtained. Subsequently, pairwise comparisons were performed using Dunn's procedure with a Bonferroni correction for multiple comparisons. Other experimental parameters, such as type of cell line used, cell viability measurement assay, and incubation time, were also explored and analysed for statistically significant results.