Nanoparticles for Biomedical Application and Their Synthesis

Abstract

Tremendous developments in nanotechnology have revolutionized the impact of nanoparticles (NPs) in the scientific community and, more recently, in society. Nanomaterials are by their definition materials that have at least one dimension in range of 1 to 100 nm. Nanoparticles are found in many types of different technological and scientific applications and innovations, from delicate electronics to state-of-the-art medical treatments. Medicine has recognized the importance of polymer materials coated with NPs and utilizes them widely thanks to their excellent physical, chemical, antibacterial, antimicrobial, and protective properties. Emphasis is given to their biomedical application, as the nanoscale structures are in the range of many biological molecules. Through this, they can achieve many important features such as targeted drug delivery, imaging, photo thermal therapy, and sensors. Moreover, by manipulating in a "nano-scale" range, their characteristic can be modified in order to obtain the desired properties needed in particular biomedical fields, such as electronic, optical, surface plasmon resonance, and physic-chemical features.

Keywords: biomedical application; drug delivery; imaging; nanoparticles; photo-thermal therapy; sensors.

Figure 1

Schematic illustration of the photo-induced intracellular controlled release of gold nanospheres. Upon UV irradiation, the photo-labile linker on the gold NPs is cleaved, changing the surface charge of gold NPs from positive to negative. The charge repulsion between the gold NPs then uncaps the mesopores and allows the release of the drugs for cancer therapy [5].

Figure 2

(A) Collected data on the number of infections by S. Aureus (MRSA), WHO 2014; (B) SEM microphotographs of Staphylococcus aureus [13]; (C) discovery void in new antibacterial drugs during the last 30 years.

Figure 3

Synthesis of ZnO nanoshells using the urease enzyme as a catalytic template. In the first step, NH₃ is generated by the hydrolysis of urea. This adjusts the pH value around the enzyme. In the second step, Zn²⁺ is added. The growth of nanoshells is governed by the local pH value at the enzyme/solution interface (De la Rica and Matsui, 2008).

Figure 4

Results of investigation into biomedically active NPs: (A,B) SEM-magnified images of gold NPs obtained by cellobiose dehydrogenase treatment of [AuCl₄]⁻ (Malel et al., 2010); (C) GEMMA spectrum of non-covalent homo-complex of Jackbean urease (Allmaier et al., 2008).