Frontiers in Nanomedicine

Nanoparticles possess unique optical and physic-chemical properties that may potentiate applications in biomedicine, in particular in diagnostics, therapy and imaging. Advances on biomolecular diagnostics strategies have greatly focused on single molecule detection and characterization of DNA, RNA or proteins through improved nanoparticle-based platforms. Nanoparticles improve analytical capability when compared to traditional techniques with high resolution and medium-high throughput. Also, particular interest has been directed at SNP detection, gene expression profiles and biomarker characterization through colorimetric, spectrometric or electrochemical strategies.

Molecular imaging has also benefited from the introduction of nanoparticles in standard techniques towards non-invasive imaging procedures that can be used to highlight regions of interest, allowing the characterization of biological processes at the cellular and/or molecular level. Several imaging modalities are associated with low sensitivity, an issue that can be tackled by the use of probes, e.g. contrast agents for X-ray and magnetic resonance imaging, radiolabelled molecules for nuclear medicine. Furthermore, nanoparticles can be used as vehicles that deliver specifically these contrast agents, leading to overcome the limitations of conventional modalities.

This chapter will discuss the use of nanoparticles in biomolecular recognition and imaging applications, focusing those already being translated into clinical settings. Current knowledge will be addressed as well as its evolution towards the future of nanoparticle-based biomedical applications.

Liver diseases, including viral hepatitis, resulting from hepatitis B or C virus infection, liver cirrhosis and hepatocellular carcinoma pose great global health challenges due to the limited curative treatment options. The application of nanoparticles has emerged as a rapidly evolving area for safely delivering therapeutic agents (i.e. drugs and nucleic acid) to treat a range of diseases, including those of the liver. In this chapter, we give an overview of various nanotechnology approaches which can be employed when treating liver diseases, focusing in particular on liver infections, fibrosis and cancer.

In this paper, the current available strategies to realize galactose-decorated nanostructured polymeric systems are summarized. These carriers are designed in order to obtain targeted drug delivery to hepatocytes via galactose (GAL) moieties, i.e. for the treatment of viral hepatitis or liver cancer that are the greater causes of global disability and mortality. Usually, the main followed strategy to obtain galactosylated polymeric carriers is to use galactosylated copolymers. The chemical modifications of preformed polymers with sugar-containing reagents is followed for obtaining lactosaminated human albumin, galactosylated phospholipid-polyaminoacid and polylactide (PLA)- polyaminoacid conjugates obtained from α,β-poly(N-2-hydroxyethyl)-D,L-aspartamide (PHEA) or lactosaminated carboxymethyl chitosan (CMC). Galactosylated polymers are also obtained via the polymerization of GAL-bearing monomers, that is for obtaining galactosylated polycarbonates. Finally, the surface galactosylation of preformed polymeric carriers is an alternative strategy that can be used to obtain a GAL-decorated system, that is for obtaining dendrimers based on polyamidoamine (PAMAM)-GAL conjugates.

Breast cancer is one of the most invasive cancers, with a high mortality rate; almost all treatment options are invasive, with significant side effects, and not always curative. Nanomedicine, the application of nanotechnology to medicine, is an interesting approach to improving the delivery of anticancer drugs, thus increasing their therapeutic index and specificity, while reducing side effects. This chapter describe the most widely studied nanoparticulate drug delivery systems, also discussing nanocarriers in clinics and recent advances in targeted drug delivery approaches for breast cancer treatment.

This chapter is dedicated to the applications of nanoparticles (NPs) for the diagnosis and treatment (or therapy) of Alzheimer’s disease (AD). Today, the Blood Brain Barrier (BBB) is considered to be one of the main challenges for treatment and diagnosis of AD. In this chapter, after a brief introduction about the disease and its related pathologies, the BBB physiology and the methodologies used for investigation of the transport of drugs across the BBB are described, together with the main physicochemical characteristic prerequisites of NPs that may be proposed as therapeutic and/or diagnostic systems for brain-located pathologies. In the second part, all the types of NPs (delivering drugs and/or imaging agents) which have been explored up-to-date for diagnosis or therapy of AD are presented, together with the advantages and disadvantages of each type. Finally, current accomplishments and future challenges are summarized.

The development of therapeutic nucleic acids has led to new strategies for treating various diseases. Non-viral, synthetic nano-vectors in gene therapy have attracted increasing attention due to their low immunogenicity and low toxicity compared to viral counterparts. Due to the molecular structure of nucleic acids, they are very prone to degradation in pH sensitive biological environments. Therefore, synthetic nano-vehicles for therapeutic delivery, known as ‘nano-vectors’, need to be cleverly designed and engineered to protect and deliver appropriate therapeutic nucleic acids to the targeted sites for action. In this chapter, a brief overview of various types of therapeutic nucleic acids is first provided, followed by analysis of the synthetic nanomaterials under development as delivery systems to carry nucleic acids. The nucleic acid-encapsulated nano-vectors discussed here open a window for a new generation of nanomedicine.