Nicola Green
@sheffield.ac.uk
University of Sheffield
RESEARCH, TEACHING, or OTHER INTERESTS
Biomaterials, Biomedical Engineering, Cell Biology
Scopus Publications
Scopus Publications
Caitlin E Jackson, Nicola H Green, William R English, and Frederik Claeyssens
IOP Publishing
Abstract Cancer is one of the leading causes of death in the 21st century, with metastasis of cancer attributing to 90% of cancer-related deaths. Therefore, to improve patient outcomes there is a need for better preclinical models to increase the success of translating oncological therapies into the clinic. Current traditional static in vitro models lack a perfusable network which is critical to overcome the diffusional mass transfer limit to provide a mechanism for the exchange of essential nutrients and waste removal, and increase their physiological relevance. Furthermore, these models typically lack cellular heterogeneity and key components of the immune system and tumour microenvironment. This review explores rapidly developing strategies utilising perfusable microphysiological systems (MPS) for investigating cancer cell metastasis. In this review we initially outline the mechanisms of cancer metastasis, highlighting key steps and identifying the current gaps in our understanding of the metastatic cascade, exploring MPS focused on investigating the individual steps of the metastatic cascade before detailing the latest MPS which can investigate multiple components of the cascade. This review then focuses on the factors which can affect the performance of an MPS designed for cancer applications with a final discussion summarising the challenges and future directions for the use of MPS for cancer models.
Mina Aleemardani, Louis Johnson, Michael Zivojin Trikić, Nicola Helen Green, and Frederik Claeyssens
Elsevier BV
Caitlin E. Jackson, David H. Ramos-Rodriguez, Nicholas T. H. Farr, William R. English, Nicola H. Green, and Frederik Claeyssens
MDPI AG
Cancer is a becoming a huge social and economic burden on society, becoming one of the most significant barriers to life expectancy in the 21st century. In particular, breast cancer is one of the leading causes of death for women. One of the most significant difficulties to finding efficient therapies for specific cancers, such as breast cancer, is the efficiency and ease of drug development and testing. Tissue-engineered (TE) in vitro models are rapidly developing as an alternative to animal testing for pharmaceuticals. Additionally, porosity included within these structures overcomes the diffusional mass transfer limit whilst enabling cell infiltration and integration with surrounding tissue. Within this study, we investigated the use of high-molecular-weight polycaprolactone methacrylate (PCL–M) polymerised high-internal-phase emulsions (polyHIPEs) as a scaffold to support 3D breast cancer (MDA-MB-231) cell culture. We assessed the porosity, interconnectivity, and morphology of the polyHIPEs when varying mixing speed during formation of the emulsion, successfully demonstrating the tunability of these polyHIPEs. An ex ovo chick chorioallantoic membrane assay identified the scaffolds as bioinert, with biocompatible properties within a vascularised tissue. Furthermore, in vitro assessment of cell attachment and proliferation showed promising potential for the use of PCL polyHIPEs to support cell growth. Our results demonstrate that PCL polyHIPEs are a promising material to support cancer cell growth with tuneable porosity and interconnectivity for the fabrication of perfusable 3D cancer models.
Caitlin E. Jackson, Iona Doyle, Hamood Khan, Samuel F. Williams, Betül Aldemir Dikici, Edgar Barajas Ledesma, Helen E. Bryant, William R. English, Nicola H. Green, and Frederik Claeyssens
Frontiers Media SA
Tumour survival and growth are reliant on angiogenesis, the formation of new blood vessels, to facilitate nutrient and waste exchange and, importantly, provide a route for metastasis from a primary to a secondary site. Whilst current models can ensure the transport and exchange of nutrients and waste via diffusion over distances greater than 200 μm, many lack sufficient vasculature capable of recapitulating the tumour microenvironment and, thus, metastasis. In this study, we utilise gelatin-containing polymerised high internal phase emulsion (polyHIPE) templated polycaprolactone-methacrylate (PCL-M) scaffolds to fabricate a composite material to support the 3D culture of MDA-MB-231 breast cancer cells and vascular ingrowth. Firstly, we investigated the effect of gelatin within the scaffolds on the mechanical and chemical properties using compression testing and FTIR spectroscopy, respectively. Initial in vitro assessment of cell metabolic activity and vascular endothelial growth factor expression demonstrated that gelatin-containing PCL-M polyHIPEs are capable of supporting 3D breast cancer cell growth. We then utilised the chick chorioallantoic membrane (CAM) assay to assess the angiogenic potential of cell-seeded gelatin-containing PCL-M polyHIPEs, and vascular ingrowth within cell-seeded, surfactant and gelatin-containing scaffolds was investigated via histological staining. Overall, our study proposes a promising composite material to fabricate a substrate to support the 3D culture of cancer cells and vascular ingrowth.
Rachel Furmidge, Caitlin E. Jackson, María Fernanda Velázquez de la Paz, Victoria L. Workman, Nicola H. Green, Gwendolen C. Reilly, Vanessa Hearnden, and Frederik Claeyssens
Frontiers Media SA
High internal phase emulsion (HIPE) templating is a well-established method for the generation of polymeric materials with high porosity (>74%) and degree of interconnectivity. The porosity and pore size can be altered by adjusting parameters during emulsification, which affects the properties of the resulting porous structure. However, there remain challenges for the fabrication of polyHIPEs, including typically small pore sizes (∼20–50 μm) and the use of surfactants, which can limit their use in biological applications. Here, we present the use of gelatin, a natural polymer, during the formation of polyHIPE structures, through the use of two biodegradable polymers, polycaprolactone-methacrylate (PCL-M) and polyglycerol sebacate-methacrylate (PGS-M). When gelatin is used as the internal phase, it is capable of stabilising emulsions without the need for an additional surfactant. Furthermore, by changing the concentration of gelatin within the internal phase, the pore size of the resulting polyHIPE can be tuned. 5% gelatin solution resulted in the largest mean pore size, increasing from 53 μm to 80 μm and 28 μm to 94 µm for PCL-M and PGS-M respectively. In addition, the inclusion of gelatin further increased the mechanical properties of the polyHIPEs and increased the period an emulsion could be stored before polymerisation. Our results demonstrate the potential to use gelatin for the fabrication of surfactant-free polyHIPEs with macroporous structures, with potential applications in tissue engineering, environmental and agricultural industries.
Mina Aleemardani, Michael Zivojin Trikić, Nicola Helen Green, and Frederik Claeyssens
Royal Society of Chemistry (RSC)
Novel PGS-co-PEG elastomers showed multifunctional characteristics such as high swelling, flexibility, bioadhesiveness and biocompatibility, and good biodegradation, mechanical properties and pH-responsive behaviour.
Fouad Junior Maksoud, María Fernanda Velázquez de la Paz, Alice J. Hann, Jeerawan Thanarak, Gwendolen C. Reilly, Frederik Claeyssens, Nicola H. Green, and Yu Shrike Zhang
Royal Society of Chemistry (RSC)
The field of porous biomaterials has grown rapidly over the past decades.
Jose R. Aguilar Cosme, Dan C. Gagui, Nicola H. Green, Helen E. Bryant, and Frederik Claeyssens
American Chemical Society (ACS)
The evaluation of novel photosensitizers (PSs) for photodynamic therapy (PDT) is difficult due to the limitations of two-dimensional cell culture and multiple parameters (dose, light intensity, uptake time), which complicate progression to in vivo experiments and clinical translation. Three-dimensional (3D) cell culture models like multicellular cancer tumor spheroids (MCTS) show great similarities to in vivo avascular tumor conditions, improving the speed and accuracy of screening novel compounds with various treatment combinations. In this study, we utilize C8161 human melanoma spheroids to screen PDT treatment combinations using protoporphyrin IX (PpIX) and drug-loaded carbon dot (CD) conjugates PpIX-CD and PpIX@CD at ultralow fluence values (<10 J/cm2). Conjugates show equivalent light-induced damage to PpIX from 1 μg/mL with significantly less dark cytotoxicity up to 72 h after exposure, shown by LDH release and dsDNA content. Fractionated treatments, carried out by dividing light exposure with 24 h intervals, demonstrate an enhanced PDT effect compared to single exposure at equal concentrations. Light sheet fluorescence microscopy combined with live/dead staining demonstrates that spheroids sustain extensive damage after PDT, with PpIX and PpIX-CD showing improved uptake compared to PpIX@CD. We show that PDT parameter screening can be carried out using a low-cost and convenient combination of assays to improve the efficiency of evaluating novel compounds.
Mina Aleemardani, Michael Zivojin Trikić, Nicola Helen Green, and Frederik Claeyssens
MDPI AG
There is a distinct boundary between the dermis and epidermis in the human skin called the basement membrane, a dense collagen network that creates undulations of the dermal–epidermal junction (DEJ). The DEJ plays multiple roles in skin homeostasis and function, namely, enhancing the adhesion and physical interlock of the layers, creating niches for epidermal stem cells, regulating the cellular microenvironment, and providing a physical boundary layer between fibroblasts and keratinocytes. However, the primary role of the DEJ has been determined as skin integrity; there are still aspects of it that are poorly investigated. Tissue engineering (TE) has evolved promising skin regeneration strategies and already developed TE scaffolds for clinical use. However, the currently available skin TE equivalents neglect to replicate the DEJ anatomical structures. The emergent ability to produce increasingly complex scaffolds for skin TE will enable the development of closer physical and physiological mimics to natural skin; it also allows researchers to study the DEJ effect on cell function. Few studies have created patterned substrates that could mimic the human DEJ to explore their significance. Here, we first review the DEJ roles and then critically discuss the TE strategies to create the DEJ undulating structure and their effects. New approaches in this field could be instrumental for improving bioengineered skin substitutes, creating 3D engineered skin, identifying pathological mechanisms, and producing and screening drugs.
Robin M. Delaine-Smith, Alice Jane Hann, Nicola H. Green, and Gwendolen Clair Reilly
Frontiers Media SA
Biomimetic replication of the structural anisotropy of musculoskeletal tissues is important to restore proper tissue mechanics and function. Physical cues from the local micro-environment, such as matrix fiber orientation, may influence the differentiation and extracellular matrix (ECM) organization of osteogenic progenitor cells. This study investigates how scaffold fiber orientation affects the behavior of mature and progenitor osteogenic cells, the influence on secreted mineralized-collagenous matrix organization, and the resulting construct mechanical properties. Gelatin-coated electrospun poly(caprolactone) fibrous scaffolds were fabricated with either a low or a high degree of anisotropy and cultured with mature osteoblasts (MLO-A5s) or osteogenic mesenchymal progenitor cells (hES-MPs). For MLO-A5 cells, alkaline phosphatase (ALP) activity was highest, and more calcium-containing matrix was deposited onto aligned scaffolds. In contrast, hES-MPs, osteogenic mesenchymal progenitor cells, exhibited higher ALP activity, collagen, and calcium deposition on randomly orientated fibers compared with aligned counterparts. Deposited matrix was isotropic on random fibrous scaffolds, whereas a greater degree of anisotropy was observed in aligned fibrous constructs, as confirmed by second harmonic generation (SHG) and scanning electron microscope (SEM) imaging. This resulted in anisotropic mechanical properties on aligned constructs. This study indicates that mineralized-matrix deposition by osteoblasts can be controlled by scaffold alignment but that the early stages of osteogenesis may not benefit from culture on orientated scaffolds.
Nicholas Farr, Jeerawan Thanarak, Jan Schäfer, Antje Quade, Frederik Claeyssens, Nicola Green, and Cornelia Rodenburg
Wiley
AbstractUnderstanding the effects that sterilization methods have on the surface of a biomaterial is a prerequisite for clinical deployment. Sterilization causes alterations in a material's surface chemistry and surface structures that can result in significant changes to its cellular response. Here we compare surfaces resulting from the application of the industry standard autoclave sterilisation to that of surfaces resulting from the use of low‐pressure Argon glow discharge within a novel gas permeable packaging method in order to explore a potential new biomaterial sterilisation method. Material surfaces are assessed by applying secondary electron hyperspectral imaging (SEHI). SEHI is a novel low‐voltage scanning electron microscopy based characterization technique that, in addition to capturing topographical images, also provides nanoscale resolution chemical maps by utilizing the energy distribution of emitted secondary electrons. Here, SEHI maps are exploited to assess the lateral distributions of diverse functional groups that are effected by the sterilization treatments. This information combined with a range of conventional surface analysis techniques and a cellular metabolic activity assay reveals persuasive reasons as to why low‐pressure argon glow discharge should be considered for further optimization as a potential terminal sterilization method for PGS‐M, a functionalized form of poly(glycerol sebacate) (PGS).
Nicholas T. H. Farr, Sameer F. Hamad, Euan Gray, Christopher M. Magazzeni, Fodio Longman, David E. J. Armstrong, Joel P. Foreman, Frederik Claeyssens, Nicola H. Green, and Cornelia Rodenburg
Royal Society of Chemistry (RSC)
“Secondary electron hyperspectral imaging (SEHI) is an innovative SEM-based analysis tool allowing spatially-resolved chemical analysis beyond elemental composition”.
Harwinder Singh, Sreejesh Sreedharan, Esteban Oyarzabal, Tufan Singha Mahapatra, Nicola Green, Yen-Yu Ian Shih, Manasmita Das, Jim. A. Thomas, Sumit Kumar Pramanik, and Amitava Das
Royal Society of Chemistry (RSC)
Two-photo active lanthanide nanorods as an efficient reagent for bimodal imaging.
Nicholas Farr, Samand Pashneh‐Tala, Nicola Stehling, Frederik Claeyssens, Nicola Green, and Cornelia Rodenburg
Wiley
AbstractA novel capability built upon secondary electron (SE) spectroscopy provides an enhanced cross‐linking characterization toolset for polymeric biomaterials, with cross‐linking density and variation captured at a multiscale level. The potential of SE spectroscopy for material characterization has been investigated since 1947. The absence of suitable instrumentation and signal processing proved insurmountable barriers to applying SE spectroscopy to biomaterials, and consequently, capturing SE spectra containing cross‐linking information is a new concept. To date, cross‐linking extent is inferred from analytical techniques such as nuclear magnetic resonance (NMR), differential scanning calorimetry, and Raman spectroscopy (RS). NMR provides extremely localized information on the atomic scale and molecular scale, while RS information volume is on the microscale. Other methods for the indirect study of cross‐linking are bulk mechanical averaging methods, such as tensile and compression modulus testing. However, these established averaging methods for the estimation of polymer cross‐linking density are incomplete because they fail to provide information of spatial distributions within the biomaterial morphology across all relevant length scales. The efficacy of the SE spectroscopy capability is demonstrated in this paper by the analysis of poly(glycerol sebacate)‐methacrylate (PGS‐M) at different degrees of methacrylation delivering new insights into PGS‐M morphology.
Jeerawan Thanarak, Hauwa Mohammed, Samand Pashneh-Tala, Frederick Claeyssens, and Nicola Green
IEEE
Poly(glycerol sebacate)-methacrylate (PGS-M) is a photocurable form of polyglycerol sebacate (PGS) that has recently been shown to be suitable for use as a scaffold for tissue engineering. It has the benefits of PGS, including biocompatibility and biodegradability, while also being much simpler to process into a variety of 3D structures. Cell compatibility has already been demonstrated on the 30% methacrylated PGS-M scaffolds. However no studies have yet assessed the collagen produced by cells growing on the PGS-M scaffold. Here we demonstrate that 50% methacrylated PGS-M 3D scaffolds are able to support the culture of human dermal fibroblasts for 1 week. We also show that collagen production is enhanced compared with the same cells growing on tissue culture plastic, with the cells producing approximately 50% more total collagen after 1 week in culture. These results go further to demonstrate the suitability of the PGS-M scaffolds for generating ECM based constructs for soft tissue engineering.
Harwinder Singh, Sreejesh Sreedharan, Karishma Tiwari, Nicola H. Green, Carl Smythe, Sumit Kumar Pramanik, Jim A. Thomas, and Amitava Das
Royal Society of Chemistry (RSC)
Two-photon active graphene quantum dots (GQDs) are obtained from extracts of the neem root.
Thomas E. Paterson, Giulia Gigliobianco, Colin Sherborne, Nicola H. Green, James M. Dugan, Sheila MacNeil, Gwendolen C. Reilly, and Frederik Claeyssens
AIP Publishing
Porous microspheres have the potential for use as injectable bone fillers to obviate the need for open surgery. Successful bone fillers must be able to support vascularisation since tissue engineering scaffolds often cease functioning soon after implantation due to a failure to vascularise rapidly. Here, we test the angiogenic potential of a tissue engineered bone filler based on a photocurable acrylate-based high internal phase emulsion (HIPE). Highly porous microspheres were fabricated via two processes, which were compared. One was taken forward and investigated for its ability to support human mesenchymal progenitor cells and angiogenesis in a chorioallantoic membrane (CAM) assay. Porous microspheres with either a narrow or broad size distribution were prepared via a T-junction microfluidic device or by a controlled stirred-tank reactor of the HIPE water in oil in water (w/o/w), respectively. Culture of human embryonic stem cell-derived mesenchymal progenitor (hES-MP) cells showed proliferation over 11 days and formation of cell-microsphere aggregates. In-vitro, hES-MP cells were found to migrate into microspheres through their surface pores over time. The presence of osteoblasts, differentiated from the hES-MP cells, was evidenced through the presence of collagen and calcium after 30 days. Microspheres pre-cultured with cells were implanted into CAM for 7 days and compared with control microspheres without pre-cultured cells. The hES-MP seeded microspheres supported greater angiogenesis, as measured by the number of blood vessels and bifurcations, while the empty scaffolds attracted host chick cell ingrowth. This investigation shows that controlled fabrication of porous microspheres has the potential to create an angiogenic, bone filling material for use as a cell delivery vehicle.
Nicola H. Green, Robin M. Delaine-Smith, Hannah J. Askew, Robert Byers, Gwendolen C. Reilly, and Stephen J. Matcher
Springer Science and Business Media LLC
AbstractEnhanced image contrast in biological second harmonic imaging microscopy (SHIM) has previously been reported via quantitative assessments of forward- to epi-generated signal intensity ratio and by polarization analysis. Here we demonstrate a new form of contrast: the material-specific, wavelength-dependence of epi-generated second harmonic generation (SHG) excitation efficiency, and discriminate collagen and myosin by ratiometric epi-generated SHG images at 920 nm and 860 nm. Collagen shows increased SHG intensity at 920 nm, while little difference is detected between the two for myosin; allowing SHIM to characterize different SHG-generating components within a complex biological sample. We propose that momentum-space mapping of the second-order non-linear structure factor is the source of this contrast and develop a model for the forward and epi-generated SHG wavelength-dependence. Our model demonstrates that even very small changes in the assumed material fibrillar structure can produce large changes in the wavelength-dependency of epi-generated SHG. However, in the case of forward SHG, although the same changes impact upon absolute intensity at a given wavelength, they have very little effect on wavelength-dependency beyond the expected monotonic fall. We also propose that this difference between forward and epi-generated SHG provides an explanation for many of the wavelength-dependency discrepancies in the published literature.
Ahtasham Raza, Helen E. Colley, Elizabeth Baggaley, Igor V. Sazanovich, Nicola H. Green, Julia A. Weinstein, Stanley W. Botchway, Sheila MacNeil, and John W. Haycock
Springer Science and Business Media LLC
AbstractSolid tumours display varied oxygen levels and this characteristic can be exploited to develop new diagnostic tools to determine and exploit these variations. Oxygen is an efficient quencher of emission of many phosphorescent compounds, thus oxygen concentration could in many cases be derived directly from relative emission intensity and lifetime. In this study, we extend our previous work on phosphorescent, low molecular weight platinum(II) complex as an oxygen sensing probe to study the variation in oxygen concentration in a viable multicellular 3D human tumour model. The data shows one of the first examples of non-invasive, real-time oxygen mapping across a melanoma tumour spheroid using one-photon phosphorescence lifetime imaging microscopy (PLIM) and a small molecule oxygen sensitive probe. These measurements were quantitative and enabled real time oxygen mapping with high spatial resolution. This combination presents as a valuable tool for optical detection of both physiological and pathological oxygen levels in a live tissue mass and we suggest has the potential for broader clinical application.
Luciana E. Bostan, Christopher Noble, Nicole Smulders, Roger Lewis, Matt J. Carré, Steve Franklin, Nicola H. Green, and Sheila MacNeil
Elsevier BV
Kayleigh Cox-Nowak, Ohood Al-Yamani, Colin A. Grant, Nicola H. Green, and Stephen Rimmer
Informa UK Limited
ABSTRACT Polymer coatings that support epithelial cell culture have been developed. Ozonolysis and subsequent workup of poly(butyl methacrylate-co-butadiene) copolymers is used to form oligomers with carboxylic acid end groups, which are then further reacted with diamines to provide poly(butyl methacrylate)s with primary amine end groups. The polymers are cast as films and used as cell culture substrates for human dermal fibroblasts and human renal epithelial cells. Fibroblast and epithelial cells adhere and proliferate on acid functional materials but on amine functional films epithelial cells show greater viability than fibroblasts. GRAPHICAL ABSTRACT
Sumit Kumar Pramanik, Sreejesh Sreedharan, Harwinder Singh, Nicola H. Green, Carl Smythe, Jim. A. Thomas, and Amitava Das
Royal Society of Chemistry (RSC)
Peptide conjugated upconverting nanoparticles for specific imaging of lysosome
Brenda F. Narice, Nicola H. Green, Sheila MacNeil, and Dilly Anumba
Springer Science and Business Media LLC
Christopher Noble, Nicole Smulders, Nicola H. Green, Roger Lewis, Matt J. Carré, Steve E. Franklin, Sheila MacNeil, and Zeike A. Taylor
Elsevier BV
Sasima Puwanun, Frazer Bye, Moira Ireland, Sheila MacNeil, Gwendolen Reilly, and Nicola Green
MDPI AG
Composite tissue-engineered constructs combining bone and soft tissue have applications in regenerative medicine, particularly dentistry. This study generated a tri-layer, electrospun, poly-ε-caprolactone membrane, with two microfiber layers separated by a layer of nanofibers, for the spatially segregated culture of mesenchymal progenitor cells (MPCs) and fibroblasts. The two cell types were seeded on either side, and cell proliferation and spatial organization were investigated over several weeks. Calcium deposition by MPCs was detected using xylenol orange (XO) and the separation between fibroblasts and the calcified matrix was visualized by confocal laser scanning microscopy. SEM confirmed that the scaffold consisted of two layers of micron-diameter fibers with a thin layer of nano-diameter fibers in-between. Complete separation of cell types was maintained and calcified matrix was observed on only one side of the membrane. This novel tri-layer membrane is capable of supporting the formation of a bilayer of calcified and non-calcified connective tissue.