Luminescent nanomaterials for biological labelling

LUMINESCENT NANOMATERIALS FOR BIOLOGICAL LABELLING Krpetić, Željka a; Porta, Francesca a *; Scarì, Giorgio b a) Università di Milano, Dip. Chimica Inorganica Metallorganica Analitica, Centre of Excellence, CIMAINA and INSTM Unit, Via Venzian 21, Milano, Italy; b) Università di Milano, Dip. Biologia 7B, Via Celoria 26, Milano, Italy. [email protected] The introduction of the labelling agents in biological systems is required for a facile microscopy detection of biological systems. Fluorescent labels nowadays represent widely developed tools in biology and medicine.1 Fluorescence parameters are usually used to obtain information on living cells. In this context, modified gold nanoparticles can be used as nano reporters. The cellular environment can be deduced from the fluorescent signals throughout the use of Fluorescence Microscopy, besides Confocal Microscopy. Herein, we report our studies on the application of gold nanoparticles as a successful probe in the Fluorescence Microscopy. We have prepared differently stabilised gold nanoparticles by reduction of NaAuCl4 using different reduction agents (NaBH4, citric acid, ascorbic acid) in the presence of stabilising ligands (fluorescent ligands: Eosin Y, 2,7-dicholorofluorescein; not-fluorescent ligands: 5-aminovaleric acid, tri-sodium citrate). Tuning the reducing agent amount and the reaction temperature, we were able to prepare differently sized gold nanoparticles in the 7-50 nm range. It was recently reported in literature the importance of the size of Au NPs in the cellular uptake. 2 These novel gold colloids were characterised by UV-vis spectroscopy, TEM and HR MASS 1H NMR Spectroscopy. For the entrance of NP in cells, mouse macrophages were incubated with gold nanoparticles for 1 h (37°C, 5% CO2), and the cellular uptake of gold nanoparticles into macrophages cells was confirmed by using Confocal Microscopy and TEM. Besides, in this study, we merged fluorescent ligands with large sized particles in order to verify their facile detection by Fluorescence Microscopy. The results showed that gold nanoparticles stabilised by commonly used fluorescent dyes (like fluorescein and eosin Y) can be applied as bioluminescent markers. These novel systems, coupling gold with the dye, have an advantage of being visualized by all three microscopy techniques, (TEM, Confocal and Fluorescence microscopy) as they satisfy their detection requirements (gold electronic density, gold fluorescence and ligand fluorescence) as they exibit the long fluorescence lifetime. Now, we are expanding the Au-luminescent dye system to lanthanide nanoparticles stabilised by biologically active molecules in order to exploit the luminescent properties of lanthanides and the bioconjugation concept. 1. Wang, F.; Tan, W.B.; Zhang, Y.; Fan, X.; Wang, M. Nanotechnology, 2006, 17, R1-R13 2. Chitrani, B.D.; Ghazani, A.A.; Chan, W.C.W. Nano Letters, 2006, 6, 662-66

Cancer research, treatment, and COVID-19

This is an editorial article

Detecting the shape of anisotropic gold nanoparticles in dispersion with single particle extinction and scattering

The shape and size of nanoparticles are important parameters affecting the biodistribution, bioactivity, and toxicity. The high-throughput characterisation of nanoparticle shape in the dispersion is a fundamental prerequisite for realistic in vitro and in vivo evaluation, however, with routinely available bench-top optical characterisation techniques, it remains a challenging task. Herein, we demonstrate the efficacy of Single Particle Extinction and Scattering (SPES) technique for the in situ detection of the shape of nanoparticles in dispersion, applied to a small library of anisotropic gold particles, with potential developments of in-line detection. The use of SPES paves the way to the routine quantitative analysis of nanoparticles dispersed in biologically relevant fluids, which is of importance for the nanosafety assessment and any in vitro and in vivo administration of nanomaterials

In depth characterisation of the biomolecular coronas of polymer coated inorganic nanoparticles with differential centrifugal sedimentation

Advances in nanofabrication methods have enabled the tailoring of new strategies towards the controlled production of nanoparticles with attractive applications in healthcare. In many cases, their characterisation remains a big challenge, particularly for small-sized functional nanoparticles of 5 nm diameter or smaller, where current particle sizing techniques struggle to provide the required sensitivity and accuracy. There is a clear need for the development of new reliable characterisation approaches for the physico-chemical characterisation of nanoparticles with significant accuracy, particularly for the analysis of the particles in the presence of complex biological fluids. Herein, we show that the Differential Centrifugal Sedimentation can be utilised as a high-precision tool for the reliable characterisation of functional nanoparticles of different materials. We report a method to correlate the sedimentation shift with the polymer and biomolecule adsorption on the nanoparticle surface, validating the developed core–shell model. We also highlight its limit when measuring nanoparticles of smaller size and the need to use several complementary methods when characterising nanoparticle corona complexes

SPARC 2022 book of abstracts

Welcome to the Book of Abstracts for the 2022 SPARC conference. Our conference is called “Moving Forwards” reflecting our re-emergence from the pandemic and our desire to reconnect our PGR community, in celebration of their research. PGRs have continued with their research endeavours despite many challenges, and their ongoing successes are underpinned by the support and guidance of dedicated supervisors and the Doctoral School Team. To recognise supervision excellence we will be awarding our annual Supervisor of the Year prizes, based on the wonderful nominations received from their PGR students.Once again, we have received a tremendous contribution from our postgraduate research community; with over 60 presenters, 12 Three-Minute Thesis finalists, and 20 poster presentations, the conference showcases our extraordinarily vibrant, inclusive, and resilient PGR community at Salford. This year there will be prizes to be won for ‘best in conference’ presentations, in addition to the winners from each parallel session. Audience members too could be in for a treat, with judges handing out spot prizes for the best questions asked, so don’t miss the opportunity to put your hand up. These abstracts provide a taster of the diverse and impactful research in progress and provide delegates with a reference point for networking and initiating critical debate. Take advantage of the hybrid format: in online sessions by posting a comment or by messaging an author to say “Hello”, or by initiating break time discussions about the amazing research you’ve seen if you are with us in person. Who knows what might result from your conversation? With such wide-ranging topics being showcased, we encourage you to take up this great opportunity to engage with researchers working in different subject areas from your own. As recent events have shown, researchers need to collaborate to meet global challenges. Interdisciplinary and international working is increasingly recognised and rewarded by all major research funders. We do hope, therefore, that you will take this opportunity to initiate interdisciplinary conversations with other researchers. A question or comment from a different perspective can shed new light on a project and could lead to exciting collaborations, and that is what SPARC is all about. SPARC is part of a programme of personal and professional development opportunities offered to all postgraduate researchers at Salford. More information about this programme is available on our website: Doctoral School | University of Salford. Registered Salford students can access full details on the Doctoral School hub: Doctoral School Hub - Home (sharepoint.com) You can follow us on Twitter @SalfordPGRs and please use the #SPARC2022 to share your conference experience.We particularly welcome taught students from our undergraduate and master’s programmes as audience members. We hope you enjoy the presentations on offer and that they inspire you to pursue your own research career. If you would like more information about studying for a PhD here at the University of Salford, your lecturers can advise, or you can contact the relevant PGR Support Officer; their details can be found at Doctoral School | University of Salford. We wish you a rich and rewarding conference experience

Preparation,Characterisation and Biological Applications of Gold Nanoparticles

The aim of this PhD thesis has been the study of metal nanoparticles and their applications in biological systems. Biological studies have been accomplished in collaboration with Dr Giorgio Scar\uec from the Department of Biology of Milan University. The research has been mailnly focused on the following arguments: - Specific design and use of 15-mer peptides as stabilisers in the gold nanoparticles preparation - Bioconjugation of peptide stabilised gold nanoparticles - A TEM study of the cellular uptake mechanism of peptide-coated GNPs into HeLa cells - Preparation of gold nanoparticles stabilised with different small organic bicompatible molecules for the selective cellular uptake into cancer cells - Use of Aloin A and Aloesin, two active components of Cape Aloe, in the preparation of gold and silver nanoparticles and their biological applications - NMR and IR studies of simple aminoalcohol stabilised gold nanoparticles - Fluorescence spectroscopy and microscopy studies of dye stabilised gold nanoparticles and their potential use as biolabels Peptide Design for the Stabilisation of Gold Nanoparticles Gold nanoparticles can be easily functionalised with biomolecules or organic ligands, and they can be attractive tools for various applications. Stabilisation of gold nanoparticles by peptide molecules is well reported in literature [1-6]. In this PhD dissertation, 15-mer peptides were designed and used as stabilisers for gold nanoparticles. Peptides designed, having periodical sequences, were planned to allow a parallel binding to gold surface [7]. One, H2N-GC(GGC)4-G-COOH (GC15), composed of 10 glycines and 5 cysteines, the other H2N-GK(GGK)4-G-COOH (GK15) composed of 10 glycines and 5 lysines. The sequences of the peptides were planned to allow the peptide to bind gold particles along its length, as observed for leucine and lysine-containing peptide bound to carboxylate-terminated thiol capped gold nanoparticles [8]. GC15 bears many potential anchor groups (SH or NH2) that can covalently bind gold particle, although the superiority of the thiol groups in covalent bonding with gold has already been stated [9]. GK15 peptide contains only primary amines that can bind gold particles in different ways depending on the pH of the sol and the pI of the peptide [10]. In particular, an electrostatic binding of GK15 can be assumed, if the NH2 groups are protonated, as observed in the case of gold-poly-lysine systems [11]. Peptides were synthesised by a standard Fmoc solid-phase procedure, purified by preparative HPLC and characterised by mass spectrometry (ESI-MS) by the professor Giovanna Speranza\u2019s research group of Milan University. Gold nanoparticles stabilised by GC15 and GK15 were prepared via the borohydride reduction method in water at pH 3, as well as via ligand exchange method. In the borohydride reduction method, gold precursor, AuCl4-, is reduced by NaBH4, in the presence of the peptide ligand obtaining a cherry red coloured gold sol. In the ligand exchange preparation method gold nanoparticles of 15 nm diameter were obtained via the Turkevich/Frens method [12-13], subsequently protected by addition of the peptide and purified by repeated centrifugation and redispersion. By different preparation methods gold particles of different diameters were obtained. Particles were purified by dialysis or centrifugation, depending on the particles size. The particles were characterised by UV-visible, ATR-FTIR, 1H NMR spectroscopies, while the particles dimensional and morphological characterisation was performed by TEM. NMR spectroscopy has revealed to be very useful tool for the characterisation in aqueous media after the lyophilisation and redispersion of the particles. This is an important result since very few nanoparticle systems can be stored in dry state and then redispersed in water [14] and studied by the NMR. These peptides containing several regularly spaced amine (lysine) or thiol (cysteine) functions have been introduced as very strongly binding \u201cmultidentate\u201d ligands to stabilise gold nanoparticles [15]. Spectroscopic investigations suggest an electrostatic multiple interactions of protonated NH2 groups of GK15 with anions present on negative gold surface (AuCl4-, AuCl2-), observing breaking and formation of H-bonding. While for GC15 peptide, the coordination to gold particles was observed via the thiol functionality, as expected. A multidentate peptide for stabilisation and facile bioconjugation of gold nanoparticles There is an increasing interest in the preparation of nanoparticles that are stable in aqueous media and can be readily functionalised with bio-molecules by established bioconjugation procedures. A number of different approaches to conjugating metal nanoparticles to biomolecules have also been reported. These include click chemistry [16], biotin-avidin coupling [17-19], ligand exchange [20, 21] and a range of standard bioconjugation procedures [22, 23]. After the GC15 and GK15 peptides showed novel and successful characteristics in the gold particle stabilisation, a new peptide of this family was specifically designed for the stabilisation and subsequent bioconjugation of gold nanoparticles. This ligand (H2N-GCGGCGGKGGCGGCG-COOH)can bind to the nanoparticle via the thiol groups of four cysteine moieties and contains a central lysine that provides an amine function to which biomolecular functionality can be readily attached. This protection method is very robust and can be used either for the one-step synthesis of relatively small (2-4 nm) particles or for the stabilisation of pre-prepared, larger (10-20 nm) colloids. Water-soluble GCK15 peptide was purchased from Aldrich (purity>95%). The resulting GCK15 coated gold particles have been characterised by TEM, UV-vis, ATR-FTIR and 1H NMR spectroscopy. Gold nanoparticles of 2.4 nm diameters were prepared in a one-step reaction by borohydride reduction of AuCl4- in the presence of the stabilising GCK15 peptide. A clear brown solution was obtained indicating the formation of gold particles in the size range below 3 nm. This conclusion was confirmed by the absence of a plasmon absorption band in the UV-vis spectrum. Gold nanoparticles of 15 nm diameters were obtained via the Turkevich/Frens method [12, 13] subsequently protected by addition of our peptide and purified by repeated centrifugation and redispersion. The UV-vis spectrum shows a plasmon absorption band at 520 nm typical for gold particles of this size range, and red gold colloidal solution. The particles are extremely stable and can be centrifuged and redispersed in pure water many times without detectable loss of material, whereas the as prepared citrate-stabilised particles cannot be redispersed in pure water after the first centrifugation. The analysis of the ligand shell in the case of 15 nm GCK15 stabilised gold particles obtained via the ligand exchange method is more difficult due to the very small proportion of peptide present in the total amount of material, which is predominantly gold. However, using high resolution magic angle spinning (HR-MAS) well resolved 1H NMR spectra of 15 nm Au@GCK15 nanoparticles were obtained. The absence of citrate peaks (quartet centred at 2.5-2.7 ppm) suggests complete ligand exchange by exposure to the peptide. The sharp doublet centred at 2.90 ppm in the spectrum of the free peptide ligand is due to the 8 cysteine \u3b2-methylene groups vicinal to the thiol groups and disappears completely upon binding to the particles. This indicates that all cysteine thiol groups are involved in the surface binding process. As an example of facile bioconjugation, a biotin moiety has been introduced via a standard coupling procedure. Biotinylation of peptide-stabilised gold nanoparticles was achieved using the standard sulfo-NHS-biotin labelling agent. Binding of the biotinylated particles to streptavidin-modified agarose beads has been demonstrated leading to an intense red colouration of the beads as evidence for successful biotinylation. Particles that have not been biotinylated do not attach to the beads. In adittion, dot blot experiments also clearly indicate efficient biotinylation of the particles. The attachment of biomolecular functionality of choice, e.g. biotin, is possible due to the presence of a central lysine residue that is not involved in the binding of the ligand to the surface of the particles. Biological application of peptide stabilised gold nanoparticles. A study of the cellular uptake mechanism. Current studies in this research area have been focused on coating biorecognition molecules on the surface of NPs to mediate cellular accumulation in different cell compartments. In bionanotechnology it is very important to have stabilisers, which could be easily functionalised with other biologically important ligands. Understanding and controlling the interactions between nanoscale objects and living cells is of great importance for arising diagnostic and therapeutic applications of nanoparticles and for nanotoxicology studies [24]. In this PhD thesis, the intracellular uptake of differently sized spherical water-soluble peptide-coated gold nanoparticles into HeLa cells has been investigated [25]. HeLa cells are human epithelial cells from a fatal cervical carcinoma transformed by human papillomavirus 18 (HPV18), classic example of an immortalized cell line widely used in medical research. For this study, gold particles stabilised with GC15, GK15 and GCK15 peptides were successfully uptaken into HeLa cells, as well as biotinylated GCK15 peptide stabilised gold particles. A comparison has been made between gold particles prepared by two different preparation methods: borohydride direct reduction and the ligand exchange preparation method. It was found that the particles prepared by using the citrate displacement method enters HeLa cells in different fashion as compared with the particles prepared by borohydride reduction method. Intracellular uptake of gold particles was investigated using TEM microscopy. Samples for TEM observations were prepared by incubation of gold particles with HeLa cells at 37\ub0C and 5% CO2 flow for 1h and the samples were then processed by a number of necessary steps (fixation, post fixation, staining, dexydration, embedding in epoxy resin, polymerisation, ultra thin cutting and mounting on TEM grids) in order to obtain 70 nm thick sections cutted with the ultra microtrome suitable for the TEM observations. Accumulation of gold particles into membrane-bound compartments inside cells, known as endosomes, is generally observed. It is shown that smaller particles (<4nm) entered cells in agglomerated form, this phenomenon were also described elsewhere [26, 27]. However, all the particles were found in endosomes, whether early or late endosomes. No particles were found in HeLa cells nuclei. In a similar fashion, biotinylated GCK15 stabilised gold particles were also found in HeLa cells endosomes. Microscopy observations have demonstrated that the mechanism of the cellular uptake of gold particles into HeLa cells is mediated via the receptor-mediated endocytosys, as evidenced by TEM micrographs of ultra thin cellular sections. It was possible to observe almost all the steps of this mechanism: 1.Specific adsorption of gold nanoparticles on the cell membrane 2.Specific recognition of gold nanoparticles by receptors present in the cell\u2019s membrane 3.Invagination of the cell membrane with formation of a membrane-bound compartments known as endosomes 4.Observation of the endosomes formed carrying gold nanoparticles present in cell\u2019s cytoplasm If the uptake mechanism of gold particles is endocytosis it is expected their exit via the exocytosis. This phenomenon would restrain their leftover time in cells, and consequently the toxicity for the organism. Selective cellular uptake of gold nanoparticles into cancer cells Current clinical X-ray contrast agents impose serious limitations on medical imaging: short imaging times, the need for catheterisation in many cases, occasional renal toxicity, and poor contrast in large patients [28]. Gold nanoparticles may overcome these limitations, as demonstrated by Hainfeld and co workers. Gold has higher absorption than iodine agents, usually used for these purposes, with less bone and tissue interference achieving better contrast with lower X-ray dose. Moreover, nanoparticles clear the blood more slowly than iodine agents, permitting longer imaging times. In this study, gold nanoparticles of 1.9 nm in diameter were injected intravenously into mice and images recorded over time with a standard mammography unit. Retention in liver and spleen resulted very low with elimination by the kidneys. These concepts were extended by using different gold nanoparticles to deliver a very large quantity of gold to tumours via intravenous injection. Combination with X-rays resulted in eradication of most tumours [29]. This PhD work was stimulated by the Hainfield\u2019s study [30-33] where a synergistic effect was observed between gold nanoparticles and the X-ray treatment resulting in tumour reduction or eradication. The survival after one year of the combined therapy was of 70%. The success of this technique is related to the high ability of gold to accumulate within tumours and absorb X-rays. Instead of the intravenous injection in a tumour tissue, different cancer cells with a range of small sized gold nanoparticles were incubated. We have studied with confocal microscopy the intracellular uptake of small sized gold nanoparticles stabilised by different organic biocompatible ligands (5-aminovaleric acid, adipic acid, L-DOPA, glucose, glycolic acid, dopamine) and their use as nanogold bioconiugates with different cancer cells (K562-leucemia myelogenous cronica caucasica humana, PC12-pheochromocytoma). Selective entrance of these particles into cancer cells was found [34]. Negative control has been performed on human epithelial cells where no entrance of gold particles was found even after 8 h of incubation. A preliminary toxicity experiment in vivo has been performed on sane CD1 mice type. Aminovaleric acid coated gold nanoparticles were chosen as model particles and injected intraperitoneally in two mice. Survival after 2 years post injection was verified, as an exceptional result. This preliminary result leads us to conclude very low or total absence of toxicity effects on living tissue and inner organs. Aloin A and Aloesin stabilised gold and silver nanoparticles and their biological applications. The inner gel of Aloe vera (Aloe barbadensis Miller) leaf is widely used in various medical, cosmetic and nutraceutical applications [35]. Many beneficial effects and biological activities of this plant as anti-viral, anti-bacterical, laxative, anti-inflammation and immunostimulation have been attributed to the polysaccharides present in the leaf pulp. Different chemical compounds, responsible for its healing properties, have been isolated so far from this specie as alkaloids, anthraquinones, anthrones, chromones, flavonoids, coumarins and pyrones, and their chemistry was thoroughly studied and reported by Dagne and coworkers [36] and professor Speranza and professor Manitto research groups [37-40]. In the anticancer drugs research, the studies on Aloe vera components have been videly undertaken. It was found by Pecere and co-workers that a hydroxyanthraquinone, naturally present in Aloe vera leaves, has a specific in vitro and in vivo antineuroectodermal tumour activity [41]. Nanoparticles synthesis using biological entities is already reported in literature, including bacteria, yeast, funghi and plants [42, 43] as clean, non-toxic and environmetally acceptable routes. Many studies on the plant use in nanobiotechnology have appeared in literature in a size-controlled formation of gold nanoparticles. Different plants are involved in the both intra and extracellular formation of silver and gold nanoparticles, reporting the use of oat (Avena sativa) [44], lemongrass extract (Cymbopogon flexuosus) [45-47], leguminous shrub Sesbania drummondii [48], Brassica juncea [49], neem leaf broth (Azadirachta indica) [50], pine (Pinus desiflora), persimmon (Diopyros kaki), ginkgo (Ginko biloba), magnolia (Magnolia kobus) and platanus (Platanus orientalis) [51]. In the listed examples, nanoparticles formation is a consequence of the Au(III) to Au(0) reduction inside plant cells or tissues. On the other hand, use of various leaf extracts utilised both as reducing agents and stabilisers in the nanoparticles preparation has been reported, as for example Emblica Officinalis fruit extract [52], Aloe vera leaf extract [53] and Cinnamon camphora leaf extract [54]. Using Aloe vera leaf extract, the formation of gold nanotriangles has been achieved as a result of the slow reduction of aqueous tetrachloroaurate anions, AuCl4-, along with the shape-directing effects of carbonyl compounds present as constituents in the plant extract. With the aim to prepare novel water soluble and biocompatible nanoparticles for biological applications, in this PhD project two active components of Aloe vera, Aloin A and Aloesin have been utilised, as stabilisers for gold and silver nanoparticles. By using different reducing agents (sodium borohydride, citric and ascorbic acid) and varying the reaction conditions (temperature and reaction time) we were able to prepare extremely stabile, water soluble Aloin A and Aloesin stabilised gold particles sized from 4 to 50 nm diameter range and approximately 5 nm sized silver nanoparticles. Prior to characterisation, particles were purified by dialysis or centrifugation, depending on the particle\u2019s size. Silver particles were characterised by UV-visible spectroscopy and the morphology and size of both silver and gold particles were investigated by TEM. Gold particles were characterised using UV-visible, ATR-FTIR and 1H NMR spectroscopies, which highlighted the interaction between gold and Aloin A and Aloesin ligand molecules. Although NMR studies of the particles ligand shell might be an issue, due to the very small content of the organic material present on the particles surface, HR-MAS 1H NMR technique has been used. Due to the very small amount of the sample needed for the analysis, this technique resulted very advantageous and promising in the studies of the particle ligand shell, appearing more functional and effective than usual NMR analysis in solution. By ligand exchange preparation method, involving citrate coated 15 nm gold particles, it was possible to exchange the citrate ligand with Aloin A and Aloesin molecules, stabilising the particles also in this way. The amount of Aloin A and Aloesin was finely tuned as well as pH of the colloidal solution allowing particle\u2019s agglomeration studies. Agglomeration of the particles was followed by TEM microscopy. More agglomerated particles were found on lower pH values (5-7) in less protected colloidal samples (<5000 ligand molecules per particle). When the pH of the colloidal solution was adjusted to higher values (8-10) and approximately 10000 ligand molecules were set up for each gold particle good stabilisation of the particles was achieved. 50 nm Aloin A and Aloesin stabilised gold nanoparticles, prepared by two different methods were applied to the vehicle study into macrophage cells. For the biological experiments by a peritoneal washing procedure, macrophage cells were extracted from a CD1 mouse, pre-emptively sacrificed by CO2 asphyxia. Macrophages were then collected in the physiological solution and seeded in the cell culture medium (MEM) at 37\ub0C in the CO2 atmosphere at 5% at sterile conditions. Subsequently, macrophages were treated with gold colloidal solution (50 nm Au-Aloin A and 40 nm Au-Aloesin particles obtained by citric acid reduction method). For the treatment, 50 \u3bcl of gold colloidal solution was added to 1 ml of the cell culture medium containing marcophage cells. Macrophages were then incubated with gold nanoparticles for 5, 15, 30 and 60 min in the same conditions (37\ub0C, at 5% CO2). After the incubation, the samples were prepared for the confocal and fluorescence microscopy observations by a number of necessary steps (centrifugation, adittion of DAPI, fixation) obtaining incubated cells on a microscopy glass slides. DAPI (4',6-diamidino-2-phenylindole) fluorescent stain was used in order to stain the cells\u2019 nuclei. Confocal microscopy observations have revealed the presence of Aloin A and Aloesin stabilised gold particles in macrophage cells cytoplasm, while the fluorescence microscopy has revealed, in some cases, the presence of these particles also in macrophages nuclei. It is an important result, since there is an emergent need for carriers that can carry bioactive agents into the cell nucleus for drug as well as gene delivery. However, in general, nanoparticles mainly localise in the cytosol (or extranucleus). Therefore, nanoparticles capable of localising into the nucleus are particularly inportant for cancer therapy. Because cancer cells have many intracellular mechanisms to limit drug molecules' access to the nucleus the direct delivery of the drug into the nucleus would circumvent these drug-resistance mechanisms [55]. NMR and IR studies of simple aminoalcohol stabilised gold nanoparticles Special properties of gold nanoparticles [56] led to their use in important applications in the areas of catalysis, optoelectronics, electron microscopy, and biology. However, the nature of the gold capping ligand bond usually remains unknown, especially for ligands bearing multiple anchor groups that can bind gold particles in different ways (carboxy, amino, hydroxy, thio