Applications of Nanomaterials in Human Health

Over the past few years, nanomaterials (NMs) have attracted the researchers because of their nanosize, physical, biological, and chemical properties compared to their bulk materials. These NMs are classified based on their size, chemical composition, shape, and sources. Different types of NMs have been synthetized from different sources and they are being classified accordingly. Many NMs have been produced in large quantities based on the requirements for many industrial applications. The two main sources through which NMs are being produced are synthetic source and naturally occurring nanoparticles (NPs). In this chapter, we discuss the types and classifications of NMs and broadly discuss the different types of nanomaterials isolated from natural and synthetic sources.

Nanomaterials are synthetized by different methods based on the types and nature of the nanomaterials. In a broad sense “top-down” and “bottom-up” are the two foremost methods to synthesize nanomaterials. In top-down method bulk materials have been reduced to nanomaterials, and in case of bottom-up method, the nanomaterials are synthesized from elementary level. The different methods which are being used to synthesize nanomaterials are chemical vapor deposition method, thermal decomposition, hydrothermal synthesis, solvothermal method, pulsed laser ablation, templating method, combustion method, microwave synthesis, gas phase method, and conventional Sol-Gel method.

Nanomaterials have shown excellent physical, electrical, and chemical properties compared to when they are in the bulk phase. Nanotechnology/biotechnology is dealing with synthesis, characterization, and applications of nanomaterials. The nanoscale materials contained tiny particles, often known as nanoparticles and they require special instrumentations and tools for their successful characterization and analysis. In this chapter, we will describe briefly the tools and techniques which are widely used for the characterization of nanomaterials. These techniques include but not limited to scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), energy-dispersive X-ray (EDX) spectroscopy, thermal gravimetric analysis (TGA), dynamic light scattering (DLS) analysis, density functional theory (DFT), zeta sizer, etc. The illustration of each technique and some cases with graphics is provided in a separate section.

Nanotechnology in the last few years has gained important and critical recognition in different fields and applications. Nano-fluids are fluids containing suspension of nanometer-sized particles. Their importance arose due to the need to enhance thermal performance of energy and thermal systems with noninvasive techniques. Nano-fluids have superior thermal properties over the base fluids such as water, mineral oil, vegetable oil, thermal oil, and synthetic oil. This feature makes them very attractive as heat transfer fluids in many applications and manufacturing processes. Nano-fluids have been recognized as nanoparticle of suspensions (1–100 nm) in a base fluid. Nano-fluids have other applications in biotechnology applications for drug delivery and advanced sensors technology. Nanoparticles are prepared from metal oxides, metals, or carbon in different forms. This chapter is intended to focus on the nanoparticle’s characteristics, behavior in applications such as momentum and mass, enhanced energy, and heat transfer, and, enhancement of solar energy applications. Other applications involving nanomaterials were also presented and discussed.

This chapter reviews the current state of the art in the use of nanomaterials in stem cell technology, tissue engineering and regenerative medicine. This new approach to therapy brings together physicians, clinical scientists, bioengineers and physicists in novel collaborations to produce innovative products and delivery systems which will revolutionise the practice of clinical regenerative medicine.

The central nervous system (CNS) is one of the most important systems in the human body, and thus, CNS disorders are causing a significant threat to human health. Researchers from around the world are making impressive efforts to come up with therapeutics and solutions to treat neurodegenerative disorders. However, the issue of brain targeting remains an unsolved challenge due to the blood-brain barrier (BBB) existence. Due to the many unique properties of engineered nanomaterials, their use could make it possible to overcome difficulties in the diagnosis and treatment of neurodegenerative disorders, provide promising neuroprotective strategies, and stimulate neuronal differentiation and nerve generation as a therapeutic approach. In contrast, despite the rapid development of the nanomaterials industry and the spread of its applications in the biomedical field, there is lacking evidence regarding their possible adverse health effects, and very little is known about their toxicity. Numerous in vivo and in vitro studies have emerged, providing evidence of neurotoxic effects of various types of nanoparticles (NPs), and therefore the advantages of nanomaterials should be weighed against their potential effects. In this chapter, we focused on the applications of nanomaterials in neurological disorders, neuronal differentiation, neuroprotection, and neurotoxicity.

Genetic testing is focused on identifying chromosome, gene, or protein changes between healthy and diseased cells or person. Genetic test outcomes can either verify or rule out possible genetic conditions and help determine whether a person is likely to develop or pass a genetic disorder. There are currently more than 1000 genetic testing and many more in the development pipeline. Therefore, the need to develop a susceptible and reliable method is vital in the diagnosis of genetic disorders. Nanomaterials offer a futuristic diagnosis platform for genetic diseases as it is a non-invasive, simple, portable, inexpensive diagnostic platform. Different nanomaterials have also been developed and functionlized with the target molecules to provide therapeutic selectively and for molecular imaging. For these reasons, the development of nanomaterials for the early detection of specific disease biomarkers in tiny amounts reaches to part-per-billion (ppb) levels, in real-time, with high sensitivity and selectivity and reliability is of great importance in disease diagnosis and disease progression monitoring. Such nanomaterials should have exceptionally high sensitivity and selectivity that combines the optical, magnetic, and electrical properties of nanomaterials with the biological selectivity and sensitivity toward their targets.

Cancer diagnostics and therapy has a lot to gain from advances in nanotechnology. Liposomes like nanoparticles can be loaded with probes and anti-cancer drugs to target cancer tissues. Drug delivery requires the specificity of targeting the cancer tissue; prolonged circulation of the nanoparticles in the blood; assessment of the tumor microenvironment (TME) and the controlled release of nanoparticles. This is particularly important from enhanced permeability and retention of nanomaterials, also known as the EPR effect. Thus, controlling the nanoparticles for different cancer types and in different formulations is critical. Efficacy and access of nanoparticles to the cancer cells may be monitored and regulated for specific tumor types that could lead to patient specific precision medicine. Hence, innovative nanotechnology can supplement existing molecular, cellular, and genetic techniques to study alterations across different cancer types, enabling the sorting of normal and malignant cells and tissues. For diagnostics, nanoparticle biosensors may be used in monitoring molecular signals specific to tumorigenesis, to assess tumor specific changes occurring in the malignant tissues. Here we also review novel nanotechnologies including the use of CRISPR/Cas9, CAR-T immunotherapy, and DNA and RNA nanotechnology studies in cancer theranostics design.

The rapid development of drug-resistant issues in pathogenic viral, bacterial, and fungal organisms and the consequent spread of infectious diseases are currently getting serious attention. Nanomaterials are the most capable therapeutic agents to cope with such issues and challenges. The extraordinary physio-chemical properties and remarkable antimicrobial capabilities of nanoparticles have triggered their application in biomedical fields. Nanomaterials from organic and inorganic nature have shown the proficiencies of disrupting microbial cells through different mechanisms. Besides with the direct effect on the microbial cell membrane, DNA, and proteins, these nanomaterials produce reactive oxygen species (ROS) that damage cell components of bacteria and viruses. Presently, a serious danger related with these antimicrobial nanomaterials is their toxicity to human and animal cells. Widespread studies have reported the amount, time, and cell-dependent toxicology of various nanomaterials. But some of them have shown excellent biocompatible properties. In this chapter, the antimicrobial activities of various nanomaterials have been described, exhibiting broad range of biological properties that are highlydependent upon their size, structure, quantity, and binding with receptor cell of different type.

The endocrine system is very essential to maintain body homeostasis. Disturbance of endocrine function leads to well-established diseases; such as diabetes mellitus, thyroid and parathyroid disorders, infertility, and obesity. There is no absolute cure for these diseases; however, current treatment aims to monitor them and prevent their further progression. Scientists are working hardly to find better treatment strategies for endocrine disorders. Nanotechnology holds a great promise in finding solutions to these diseases, and this field is advancing very rapidly because of the targeted type of drug delivery, and hence, it reduced the side effects of the current medications. This chapter highlights the current state of researches concerning the use of nanotechnology in managing three examples of endocrine diseases: thyroid dysfunction, diabetes mellitus, and obesity. For example, nanotechnology has been implemented in finding non-invasive routes of insulin delivery such as oral, nasal, or transdermal routes. Glucose nanosensors have been invented in order to improve the accuracy of detection of serum glucose. It is important to emphasize that this field of research is still in the preclinical stage and more work is needed to provide evidence of its safety. Immune response and toxicity are the main issues that concern researchers when using nanotechnology.

Nanomedicine is a very rapidly evolving field which has many biological, biomedical, and healthcare applications. Due to various beneficial properties of the nanomaterials, such as vast surface area, high biocompatibility, and biodistribution properties, these nanoparticles have been used to develop many useful products. Many of these nano-based products are under various developmental stages and many nanodrugs have been reported to have entered clinical phases of testing for various treatment conditions. In this chapter, we discuss some of the major nanoproducts which are developed for the treatment, diagnosis, and biosensing purposes.

Understanding the dynamics of research activities in nanomaterials for human health research area is a key to devise an informed strategy for researchers, decision-makers in addition to various players in the broader research community. This goes beyond researchers involved directly in such research activities as governments, funders, and specific industrial firms need also to allocate hot areas and centers of excellence within the nanomaterial for human health research area in order to act and devise plans accordingly. This chapter offers a comprehensive and thorough diagnosis of the research publications’ output and identifies major countries, universities, and other stakeholders. In addition to this, an overview of the patenting activities inside the nanomaterial for human health research area is introduced. Having covered research articles and patents, this chapter serves as a good starting point that feeds into an optimized approach of this research area. The growing research output in the last 10 years demonstrates again the relevancy and importance of this research areas and urges for even more investment and funding of scientific projects that undertake topics of nanomaterials with human health approaches.

Mesostructured silica, dendrimers, and allotropes of carbon were exhaustively used in biomedical, cosmetics, semiconductors, and food industry applications. Considering the huge prospect of nanomaterials, their potential hazards on exposure to humans and their related ecotoxicological effects needs to be summarized. Nanoparticles with size below 100 nm could pass into the lung and then to blood through inhalation, ingestion, and skin contact. As nanotechnology innovation is expected to achieve $ 2231 million by 2025, humans will be exposed ever increasingly in day-to-day life and in industries. In this review, the latest synthetic methodology of silica, dendrimers, and CNTs, their biological applications (in vitro and in vivo) related to toxicity were discussed. In terms of structured silica, the toxic and non-toxic effect induced by specific templates (cetylpyridinium bromide, cetyltrimethylammonium bromide, dipalmitoylphosphatidylcholine, C16L-tryptophan, C16-L-histidine, and C16-L-poline) that are used to generate mesoporous silica, silica nanoparticle sizes (25, 50, 60, 115, and 500 nm), and silane functionalization (NH₂ and COOH) were discussed. The recent applications of different generations (G3, G4, G5, and G6) of amphiphilic Janus dendrimers were discussed along with toxicity effect of different charged dendrimers (cationic and anionic) and effect of PEGylation. Recent synthesis, advantages, and disadvantages of carbon nanotubes (CNTs) were presented for structures like single walled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs). The influence of diameter of SWCNTs (linear and short), thickness (thin and thick), effect of oxidation, metal oxide species (TiO₂, Fe, and Au), and biocompatible polymers (polyethylene glycol, bisphosphonate, and alendronate) were shown in relation to molecular pathways in animal cells.

Even after many discoveries and inventions of new nanomaterial devices for biomedical applications, still there were no stringent rules and regulations framed for the pharmaceutical products or the biomedicines developed from it. As a result, there was a bridge gap between biomedical advancement and clinical trials. This chapter discusses about the nanomaterial’s advancement, importance and its key role in the development of novel and improvised biomedical devices for many health-related issues in human body. There was a sharp edge of advancement with many novel inventions, at the same time there was a lack in discipline in the ethical issues and advancement related to it. Hence this chapter clearly connects the bridge between the issues and presented some improvisations for the development of nanobiomedical devices and their ethical issues.

Over the advancement of nanotechnology, a vast number of nanomaterials have been developed and successfully utilized in various applications. Specifically in biomedical applications, still it is a challenging to fabricate nanomaterials with good functional properties for acheiveing better therapeutics. To overcome the limitations of common nanomaterials, smart materials are grabbing more significant attention recently. In earlier days, these smart materials are often defined as a material which can respond in a timely manner to the surrounding environment. Thereafter, definition of smart materials has been expanded that the material that can stimuli by external factors and results a new kind of functional properties. Stimuli agents are further classified as light, temperature, electric, magnetic field, stress, pressure, pH, etc. These controlled abilities of smart materials make them particularly interesting to utilize in various applications such as controlled release of drugs, treatment of various diseases, biosensors, etc. So it is very important to know the various kind of smart nanomaterials and their unique properties under specific stimulating agents. Therefore, in the present chapter, we aim to show various classification of smart nanomaterials and its beneficial advantages in biomedical applications in the past to the future.