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Professor Stephen Hart

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Telephone Number: 0207 905 2228

Publications

Background

After receiving my BSc in Genetics at Liverpool University in 1981, I spent most of the next ten years in South Africa, firstly at University of the Witwatersrand ("Wits") and South African Institute for Medical Research (SAIMR) where I worked with Professor Trefor Jenkins on projects related to human genetic and evolutionary studies in the peoples of southern Africa. It was during this period, while studying for a masters degree in partial adenosine deaminase (ADA) deficiency, that I first became interested in the possibilities of gene therapy for genetic diseases. In 1987 I moved to the University of Cape Town Microbiology Department to develop my knowledge and skills of recombinant DNA technology, and, not to mention, beach life in the Western Cape! After graduating with my PhD in 1991 I joined the lab of Bob Williamson at St. Mary's Hospital Medical School in Paddington, on my first postdoc project into gene therapy for cystic fibrosis, the gene for which had been discovered less than two years earlier. Three years later I joined the Institute of Child Health where my group continues to develop genetic therapies for respiratory diseases associated with cystic fibrosis and primary ciliary dyskinesias (collaboration with Chris O'Callaghan and Hannah Mitchison), siRNA therapy for neuroblastoma (collaboration with Andy Stoker), exon-skipping oligonucleotide therapeutics for Duchenne muscular dystrophy (collaboration with Francesco Muntoni) and recently siRNA therapies for skin diseases (collaboration with Wei-Li Di and Veronica Kinsler).

Main Interests/Achievements

Genetic therapies require a means of delivery of the therapeutic gene or oligonucleotide to cells of the affected tissue and this is perhaps the most important barrier to overcome in the development of gene-based therapies. Viral vectors are widely used and have had some major clinical successes but for some applications their immunogenicity limits their effectiveness for applications where repeated in vivo delivery is required. Thus, we have focused on the use of non-viral formulations since these are less immunogenic, have a wide range of packaging capacities, are safer than viruses and are more easily produced in scales required for clinical uses.

In our group we are developing multifunctional nanoparticles termed Receptor-Targeted Nanocomplexes (RTN) comprising mixtures of cationic liposomes (L) and cationic targeting peptides (P) which self-assemble, electrostatically on mixing with DNA (D) or siRNA (R). RTN formulations comprise a peptide, P, which packages nucleic acids through a cationic K16 motif and targets receptors through short peptide ligands such as RGD integrin-targeting motifs (Tagalakis et al., 2011). The liposome component of the RTN includes a neutral lipid, DOPE, which enhances transfection by destabilising the endosomal bilayer allowing releasing the nucleic acid into the cytoplasm after endocytic uptake of the nanocomplexes and before endosomal degradation can occur. Peptide and lipid chemistry allows a wide range of functionalities to be incorporated into the nanocomplexes so that these formulations increasingly resemble artificial viruses in their abilities to overcome cellular barriers to transfection. 

Imaging

Recent developments of RTN formulations in our lab include the incorporation of contrast agents for real time imaging of biodistribution by MRI in brains (Kenny et al., 2013) and tumours (Kenny et al., 2013) and radiolabel incorporation for gamma scintigraphy imaging of RTNs in different regions of the lungs of pigs after nebulisation (Manunta et al., 2013).

RTNs for Neuroblastoma and Brain

We are developing negatively-charged (anionic) RTNs which are potentially less toxic and which show greater cell specificity of transfection than cationics. These formulations are in development for delivery of gene therapies in the brain (Tagalakis et al., 2014) and neuroblastoma therapeutics with siRNA (Tagalakis et al, ms in preparation).

Nanocomplexes containing siRNA have also been optimised for their in vitro transfection efficiency and biophysical properties (Tagalakis et al., 2013;2011), and have shown in vivo efficacy in brain, tumour and lung (ms's in preparation).

CF and PCD Gene Therapy with Minicircle Vectors

Derivatives of nanocomplexes are in development for in vivo gene delivery to lung for CF (Tagalakis et al., 2008, Manunta et al., 2011;2013) and PCD gene therapy. We are also developing minicircle DNA for packaging into RTNs for gene therapy of CF and PCD as they lack the bacterial DNA backbone and so achieve higher levels of transfection than plasmid vectors both in vitro and in vivo.

siRNA Therapies for Brain and Lung

We have also developed specific RTNs for transfection of vascular tissues in rat (Meng et al., 2006) and rabbit models (Meng et al., 2013) achieving therapeutic efficacy in preventing neointimal hyperplasia.

Grants (last 5 years/current)


Great Ormond Street Hospital children's charity Leadership Grants (Ref V1298)

April 2013 - 31st March 2016
"Gene therapy for cystic fibrosis". £123,030

 Association for International Cancer Research (AICR, ref no. 12-1272) (PI)

July 2012 - July 2014
Collaborator Arturo Sala, ICH.  "RNA interference therapeutics for neuroblastoma"

Cystic Fibrosis Trust (Co-I)

Oct 2012 - Oct 2015
"In search of a drug to improve F508 CFTR channel function: development of a gating-sensitive fluorescent probe and compound library screening".  £101,590

Neuroblastoma Society (CO-I)

Sept 2013 - Sept 2015
PI Andy Stoker, ICH.  "Indetification of tyrosine phosphatases that suppress differentiation and promote survival in neuroblastoma cells".  £129,356

Children with Cancer UK and GOSH Children's Charity (Co-I) (Ref No: 2012-NAT-30)

Aug 2012 - Aug 2014
PI Andy Stoker, ICH.  "Comibination Treatments to Drive Neuroblastoma Tumour Differentiation and Senescene".  £134,488

Wellcome Trust (PI)

Sept 2011 - Sept 2014
Co-I R. McAnulty, UCL.  "Tropical delivery of siRNA to the airways with nanoparticles for therapy of cystic fibrosis".  £250,000

 Association Francais Contre les Myopathies (Co-I)

April 2011 - 31st March 2010
"Advances in Oligonucleotide Mediated Exon Skipping For DMD And Related Disorders!.  International MDEX Consortium - my role is in delivery systems for oligonucleotides.  PIs Francesco Muntoni, ICH, Matthew Wood and Kay Davies(Oxford).  Application Total £5,585,305 (£2,257,007 for ICH).  Awarded approximately 63% £3,518,742 (£1,421,914 for ICH).

CHRAT PhD studentship (PI)

Oct 2010 - Oct 2013
Mr. Mustafa Munye "Gene therapy for primary cilliary dyskinesia."  £60,000

EPSRC (PI)

May 2009 - 30th April 2012
Co Investigators Hailes, Tabor, Lythgoe (UCL), Lawrence (King's College London), Gill, Love (Bristol).  "Nanoparticles for the Targeted Delivery of Therpeutic Agents to the Brain for the Treatment of Dementias Collaboration with UCL chemistry, Kings College London, University of Bristol, North Bristol NHS Trust.  Total grant £2,040,038 of which £1,391,286 for UCL.

Technology Strategy Board/EPSRC/BBSRC (PI)

Feb 2008 - Jan 2010
Co-I J.McEwan, UCL. "Adjunct gene therapy for coronary artery bypass grafting".  Collaboration with Genex Biosystems Ldt and Ark Therapeutics Ltd. (£543,261; £232,042 for ICH)