Doctorate in Biology, Specialty in BiotechnologyThe use of gold nanoparticles (AuNPs) has been gaining momentum in molecular diagnostics due to their unique physico-chemical properties these systems present huge advantages, such as increased sensitivity, reduced cost and potential for single-molecule characterisation.
Because of their versatility and easy of functionalisation, multifunctional AuNPs have also been proposed as optimal delivery systems for therapy (nanovectors). Being able to produce such systems would mean the dawn of a new age in theranostics (diagnostics and therapy)driven by nanotechnology vehicles.
Nanotechnology can be exploit for cancer theranostics via the development of diagnostics systems such as colorimetric and imunoassays, and in therapy approaches through gene therapy, drug delivery and tumour targeting systems.
The unique characteristics of nanoparticles in the nanometre range, such as high surface-tovolume ratio or shape/size-dependent optical properties, are drastically different from those of their bulk materials and hold pledge in the clinical field for disease therapeutics This PhD project intends to optimise a gold-nanoparticle based technique for the detection of
oncogenes’ transcripts (c-Myc and BCR-ABL) that can be used for the evaluation of the
expression profile in cancer cells, while simultaneously developing an innovative platform of multifunctional gold nanoparticles (tumour markers, cell penetrating peptides, fluorescent dyes) loaded with siRNA capable of silencing the selected proto-oncogenes, which can be
used to evaluate the level of expression and determine the efficiency of silencing. This work is a part of an ongoing collaboration between Research Centre for Human Molecular
Genetics, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Portugal and Biofunctional Nanoparticles and Surfaces Group, Instituto de Nanociencia de Aragón, Spain within a European project [NanoScieE+ - NANOTRUCK].
In order to achieve this goal we developed effective conjugation strategies to combine, in a highly controlled way, biomolecules to the surface of AuNPs with specific functions such as:
ssDNA oligos to detect specific sequences and for mRNA quantification; Biofunctional
spacers: Poly(ethylene glycol) (PEG) spacers used to increase solubility and biocompatibility and confer chemical functionality; Cell penetrating peptides: to overcome the lipophilic barrier of the cellular membranes and deliver molecules into cells using TAT peptide to achieve cytoplasm and nucleus; Quaternary ammonium: to introduce stable positively charged in gold nanoparticles surface; and RNA interference: siRNA complementary to a master regulator gene, the proto-oncogene c-Myc, that is implicated in cell growth, proliferation, loss of differentiation, and cell death.
In order to establish that they are viable alternatives to the available methods, these innovative nanoparticles were extensively characterized on their chemical functionalization, ease of uptake, cellular toxicity and inflammation, and knockdown of MYC protein expression in several cancer cell lines and in in vivo models.Fundação para a Ciência e Tecnologia - (SFRH/BD/62957/2009); PTDC/BIO/66514/2006; NANOLIGHT-PTDC/QUI-QUI/112597/2009; Silencing the silencers via multifunctional gold nanoconjugates towards cancer therapy - PTDC/BBB-NAN/1812/201
