Dr Sabeel Valappil

Sabeel is the programme leader for BSc Microbiology and teaches on various programmes within the Chester Medical School.

• MD4008 - Introduction to Microbiology
• MD5026 - Immunology
• MD5028 - Advanced Microbiology
• MD6028 - Virology
• MD6030 - Medical Microbiology
• MD6033 - Clinical Immunology

Sabeel has attracted research grants worth over £1.5 million and concentrates his research on the following areas:

Development of antibacterial materials

Antibiotic-resistance is increasingly becoming a key public health risk and threatening decades of advances in the treatment of infections. His research focus in biomaterials that can be tailor-made to promote a specific biological response. Currently he is leading research on the controlled delivery of antibacterial ions from Nanocomposites and Phosphate-based glasses e.g., silver, copper, zinc, gallium and scandium.

Production of nanocomposites includes the development of biocompatible and biodegradable materials such as carboxy methyl cellulose, lactoferrin and Polyhydroxyalkanoates (an emerging class of bio polymeric material derived from bacteria).

In vitro modelling of the biofilm ecosystem

This research involves developing, validating and utilising a diverse range of biologically relevant laboratory models of biofilm environments, such as the constant-depth film fermenter, to develop treatments and inform patient care. As part of a joint BBSRC/Unilever research project, Sabeel’s group work on utilising next-generation sequencing such as microbiome 16S rRNA, metagenomics of DNA and RNA to gain functional insights into biofilm communities.

Non-invasive early detection of shifts in microbial community structure

To facilitate research in this area, bioinformatics tools and data analyses of complex network patterns of human microbiomes are utilised. Imaging systems, such as Quantitative Light-Induced Fluorescence (QLF), have also been used to analyse in situ biofilm community structure to establish its link with an individual’s health status.

People living with systemic conditions often report disordered eating behaviours, which has implications for diet and health outcomes. As part of a joint BBSRC/G research project, Sabeel and his collaborators work to measure non-pathological eating traits to explore associations between the incidence of systemic conditions, body satisfaction, and oral health in a UK population sample.

Sabeel has published 40 peer reviewed journal articles, 80 national/international conference abstracts and 2 invited book chapters.

Journal Articles

Valappil SP, Abou Neel EA, Zakir Hossain KM, Paul W, Cherukaraveedu D, Wade B, Ansari TI, Hope CK, Higham SM, Sharma CP (2024). Novel lactoferrin-conjugated gallium complex to treat Pseudomonas aeruginosa wound infection. International Journal of Biological Macromolecules.258:128838.

Smout, E., Palanisamy, N., Valappil, S. P. (2023). Prevalence of vancomycin-resistant Enterococci in India between 2000 and 2022: a systematic review and meta-analysis Antimicrobial Resistance & Infection Control.

Smith, P M., Bowles, J., Jellicoe, M., Mathur, M., Molyneux, L., Randell L.A., Smith, R.N., Valappil, S. P. (2023). Introducing open-book examinations in clinical education: A case study. Developing Academic Practice.

Rajadorai, S., Harris, G., Robinson, A., Miles, E. J., Roberts, J. M., Cooper, L., Abou Neel, E.A., Higham, SM., Flannigan N.L., Valappil, S. P. (2022). Antibacterial, remineralising zinc oxide-doped phosphate-based glasses. Materials Letters. 306, 130813.

 Valappil SP, Abou Neel EA, Pickup DM, Burden E, Sahdev R, Miles EJ, Cooper L, Ansari TI, Hanna JV, Higham SM (2022). Antibacterial, Remineralising and Matrix Metalloproteinase Inhibiting Scandium-doped Phosphate Glasses for Treatment of Dental Caries. Dental Materials.38, 94-107.

Roberts JM, Bradshaw DJ, Lynch RJM, Higham SM, Valappil SP (2021). Quantifying the Demineralisation of Enamel Using a Hyperspectral Camera Measuring Fluorescence Loss. Photodiagnosis and Photodynamic Therapy. 36,102603.

Roberts JM, Bradshaw DJ, Lynch RJM, Higham S. Valappil SP (2021). The Cariogenic Effect of Starch on an Oral Microcosm Grown Within the Dual Constant Depth Film Fermenter. PLoS One 16: e0258881.

Abou Neel, E. A., Hossain, K. M. Z., Abuelenain, D. A., Abuhaimed, T., Ahmed, I., Valappil, S. P., Knowles, J. C. (2021). Antibacterial effect of titanium dioxide-doped phosphate glass microspheres filled total-etch dental adhesive on S. mutans biofilm. International Journal of Adhesion and Adhesives, 108, 102886.

Abou Neel EA, Kiani, A, Valappil SP, Moradan NM, Baek SY, Hossain KMZ, Felfel RM, Ahmed I, Divakarl K, Chrzanowski W, Knowles JC. (2019) Glass microparticle- versus microsphere-filled experimental dental adhesives. Journal of Applied Polymer Science.136, 47832.

Owens, G.J., Lynch, R.J.M., Hope, C.K., Cooper, L., Higham, S.M., Valappil, S. P. (2017); Evidence of an In Vitro Coupled Diffusion Mechanism of Lesion Formation within Microcosm Dental Plaque. Caries Research. 51,188-197.

Lackey, B., Nunes, Q., Higham, S.M., Fernig, D., Valappil, S.P. (2016); In silico analyses of heparin binding protein expression in human periodontal tissues. BMC Research Notes. 9, 53-60.

Sadeq, A., Risk, J.M., Pender, N., Higham, S.M., Valappil, S.P. (2015); Evaluation of the co-existence of the red fluorescent plaque bacteria P.gingivalis with S. gordonii and S. mutans in white spot lesion formation during orthodontic treatment. Photodiagnosis and Photodynamic Therapy. 12,232-237.

Sahdev, R, Ansari, T., Higham, S.M., Valappil, S.P. (2015); Potential use of gallium-doped phosphate-based glass material for periodontitis treatment. Journal of Biomaterials Applications. 30,85-92.

Valappil SP, Owens, G.J., Miles, E.J., Farmer N.L., Cooper, L., Miller G., Clowes, R., Lynch R.J.M and Higham S M (2014). Effect of Gallium on Growth of Streptococcus mutans NCTC10449 and Dental Tissues. Caries Research 48,137-146.

Pickup DM, Newport RJ., Barney, E., Kim, J.Y., Valappil SP and Knowles JC (2014). Characterisation of phosphate coacervates for potential biomedical applications. Journal of Biomaterials Applications 28, 1226 -1234.

Valappil SP and Higham S M (2014). Antibacterial Effect of Gallium and Silver on Pseudomonas aeruginosa Treated with   Gallium-Silver-Phosphate Based Glasses. Bio-Medical Materials and Engineering 24, 1589-1594.

Valappil SP, Yiu H H P, Bouffier L, Hope C K, Evans G, Claridge J B, Higham S M, and Rosseinsky M J (2013). Effect of Novel Antibacterial Gallium-Carboxymethyl Cellulose on Pseudomonas aeruginosa . Dalton Transactions  42, 1778 – 1786.

Valappil SP, Coombes M, Wright L, Owens GJ, Lynch RJM, Hope CK and Higham SM (2012) Role of Gallium and Silver from Phosphate Based Glasses on in vitro dual species oral biofilm models of Porphyromonas gingivalis and Streptococcus gordonii. Acta Biomaterialia 8, 1957–1965.

Hope C K, de Josselin de Jong, E, Valappil, SP, Higham, SM (2011) Photobleaching of Intrinsic Red Fluorescence in Oral Biofilms and Extracted Teeth. Journal of Periodontal Research 46, 228-234.

Misra SK, Ansari T, Valappil SP, Mohn D, Philip SE, Stark WJ, Roy I, Knowles JC, Salih V, Boccaccini AR (2010) Poly(3-hydroxybutyrate) multifunctional composite scaffolds for tissue engineering applications. Biomaterials. 31, 2806-2815.

Misra SK, Ansari T, Mohn D, Valappil SP, Brunner TJ, Stark WJ, Roy I, Knowles JC, Sibbons PD, Boccaccini AR and Salih V (2010) Effect of nanoparticulate bioactive glass on bioactivity and cytocompatibility of P(3HB) composites. Journal of Royal Society Interface. 7, 453-465.

Misra SK, Ohashi F, Valappil SP, Knowles JC, Roy I, Silva SRP, Salih V, Boccaccini AR (2010) Characterisation of carbon nanotube (MWCNT) containing P(3HB)/bioactive glass composites for tissue engineering applications. Acta Biomaterialia. 6,735-742.

Chrzanowski W, Valappil SP, Dunnill CW, Abou Neel E A, Lee K, Parkin IP, Wilson M, Armitage DA, Knowles JC (2010) Impaired Bacterial Attachment To Light Activated Ni-Ti alloy. Materials Science and Engineering: C 30. 225-234.

Valappil S P, Ready D, Abou Neel E A, Pickup D M, O'Dell L A, Chrzanowski W, Pratten J, Newport R J, Smith M E, Wilson M and Knowles J C (2009) Controlled delivery of antimicrobial gallium ions from phosphate-based glasses. Acta Biomaterialia,5.1198-1210.

Abou Neel EA, Pickup DM, Valappil SP, Newport RJ and Knowles JC (2009) Bioactive functional materials: a perspective on phosphate-based glasses. Journal of Materials Chemistry,19.690-701.

Pickup DM, Valappil SP, Moss RM, Twyman HL, Guerry P, Smith ME, Wilson M, Knowles JC and Newport RJ (2009) Preparation, structural characterisation and antibacterial properties of Ga-doped sol-gel phosphate-based glass. Journal of Material Science,44.1858-67.

Abou Neel E A, Chrzanowski W, Valappil S P, O'Dell L A, Pickup D M, Smith M E, Newport R J and Knowles J C (2009) Doping of a high calcium oxide metaphosphate glass with titanium dioxide. Journal of Non-Crystalline Solids,355.991-1000.

Pickup D M, Moss R M, Qiu D, Newport R J, Valappil S P, Knowles J C and Smith M E (2009) Structural characterization by x-ray methods of novel antimicrobial gallium-doped phosphate-based glasses. Journal of Chemical Physics,130.064708.

Mehdawi I, Abou Neel E A, Valappil S P, Palmer G, Salih V, Pratten J, Spratt D A and Young A M (2009) Development of remineralizing antibacterial dental materials. Acta Biomaterialia. 5, 2525-2539.

Valappil S P, Knowles J C and Wilson M 2008; Effect of silver-doped phosphate-based glasses on bacterial biofilm growth. Applied and Environmental Microbiology. 74.5228-30.

Valappil, S.P., Ready, D., Abou Neel, E. A., Pickup, D. M., Chrzanowski, W., O’Dell, L.A., Newport, R.J., Smith, M.E., Wilson, M., Knowles J.C., 2008; Antimicrobial Gallium-doped  Phosphate-based Glasses. Advanced Functional Materials 18, 732-741

Valappil, S.P., Rai, R., Bucke, C., Roy, I. 2008; Polyhydroxyalkanoate biosynthesis in Bacillus cereus SPV under varied limiting conditions and an insight into the biosynthetic genes involved. Journal of Applied Microbiology .104.1624-1635

Valappil, S.P., Pickup, D.M.,  Carroll, D.L.,   Hope, C.K., Pratten, J., Newport, R.J., Smith, M.E.,  Wilson, M., Knowles J.C., 2007; Effect of silver content on the structure and antibacterial activity of silver-doped phosphate-based glasses. Antimicrobial Agents and Chemotherapy 51, 4453-61.

Valappil, S.P., Misra, S.K., Boccaccini, A.R., Keshavarz, T., Bucke, C., Roy, I. 2007; Large scale production and efficient recovery of P (3HB) with improved material properties from a newly isolated Bacillus sp. Journal of Biotechnology  132, 251-258..

Valappil, S.P., Peiris, D., Langley, G.J., Herniman, J., Boccaccini, A.R., Bucke, C., Roy, I. 2007; Identification and Characterization of a newly isolated Polyhydroxyalkanoate  producing Bacillus spp. with potential for novel  copolymer production Journal of Biotechnology 127, 475-487.

Valappil, S.P., Boccaccini, A.R., Bucke, C., Roy, I. 2007; Polyhydroxyalkanoates in Gram positive bacteria: insights from the genera Bacillus and Streptomyces. Antonie van Leeuwenhoek. 91, 1-17.

Ahmed, I., Abou Neel, E.A., Valappil, S.P., Nazhat, S.N., Pickup, D.M., Carta, D.,  Carroll, D.L., Newport,R.J., Smith, M.E., Knowles, J.C.2007; The structure and properties of silver-doped phosphate- based glasses. Journal of Biomaterials Science. 42, 9827–9835.

Skelton, K.L., Glenn, J.V., Clarke, S.A., Georgiou. G.,Valappil S.P., Nazhat, S.N., Knowles, J.C., Jordan, G.R.2007; Effect of ternary phosphate based glass compositions on osteoblast and osteoblast-like proliferation, differentiation and death in vitro. Acta Biomaterialia. 3, 563-572.

Misra, S.K, Watts, P S, Valappil, S.P., Roy, I., Silva, SRP., Boccaccini, A.R. 2007; Poly(3-hydroxybutyrate)/bioglass® composite films containing carbon nanotubes. Nanotechnology.18, 075701-075708.

Misra, S.K, Nazhat, S.N.,Valappil, S.P., Torbati, M.M., Roy, I., Boccaccini, A.R. 2007; Fabrication and characterisation of biodegradable Poly (3-hydroxybutyrate) P3HB composite films containing Bioglass®. Biomacromolecules. 8, 2112-2119.

Misra, S.K, Valappil, S.P., Roy, I., Boccaccini, A.R. 2006; Polyhydroxyalkanoate (PHA)/inorganic phase composites for tissue engineering applications Biomacromolecules 7, 2249-2258.

Valappil, S.P., Misra, S.K., Boccaccini, Roy, I. 2006; Biomedical applications of polyhydroxyalkanoates, animal testing and in vivo tissue responses. Expert Review on Medical Devices.3, 853-868.

Verma, S., Bhatia, Y., Valappil, S.P., Roy, I. 2002; A possible role of poly-3-hydroxybutyric acid in antibiotic production in Streptomyces Archives of Microbiology 179, 66-69.

Contribution to books (invited)

Valappil SP, (2018). Nanosystems and Antibacterial Applications'. In: C.P. Sharma ed. Nanotechnology: Drug Delivery Systems. London, Elsevier UK.

Valappil SP, (2014). Antimicrobial Interfaces. In: Hutmacher, Chrzanowski ed(s). Biointerfaces : Where Material Meets Biology. London, Royal Society of Chemistry (RSC).

Thesis

Valappil, S. P. Production of polyhydroxyalkanoates (PHAs) by Gram-positive bacteria. 2005, PhD thesis, University of Westminster.

2008      PG Cert Learning and Teaching in Higher Education, University College London, UK

2005      Ph.D. Molecular Microbiology, University of Westminster, UK

2001      M.Sc. Applied Microbiology, University of Westminster, UK

1999      B.Sc. Microbiology, University of Madras, India