**1. Introduction**

Graphene consists of a single layer of carbon atoms packed into a honeycomb lattice. Its particular atomic organization of the carbon atoms affords graphene a set of very unique characteristics that justify the attention researcher of all fields have given it. The more standing out properties are a high mechanical strength, thermal and electrical conductibility, high surfaceto-mas ratio, and relative transparency [1]. Many studies use graphene oxide (GO) or reduced

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

graphene oxide (rGO) instead of pristine graphene, because the oxidized forms are easier to process and can be dispersed in water while at the same time maintaining most of graphene's properties.

While studying toxicity it is very important to analyze the effect on the reproductive system and development because this can lead to more lasting effects. Graphene plaques seem unable to penetrate the blood-testis barrier in mice, and therefore sperm function and male reproductive activity show no alteration even for high doses of graphene [12]. In the female, there are no alterations if GO is administered before mating or during early gestation, and the female can give birth to healthy litters. However, if administered during late gestation, it leads to abortion and even death of the pregnant mice for high dose [13]. Injection of chicken eggs leads to reduced vascularization of the heart [14]. Despite showing no obvious malformation or mortality in zebrafish embryo, GO aggregates were retained in many organelles leading to

A Scientometric Study on Graphene and Related Graphene-Based Materials in Medicine

http://dx.doi.org/10.5772/intechopen.77288

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Even though graphene toxicity has drawn a lot of attention from scientists, there is a remarkable lack of understanding of the mechanisms underlying this effect. The use of different models and forms of graphene seem to lead to very dissimilar conclusions. There is a clear need for more systematic and in-depth studies, before graphene can be brought to its full

In this context, it is evident that, in one hand, graphene and graphene-related materials are even more used in medicine and bioengineering; on the other one, the information about their safety, their toxicity, and about the way of their possible interaction with living being (and

For this reason, here, we carried out a scientometric study on this very interesting topic, with the aim to study the scientific literature and to identify the most relevant topic and the coun-

We accessed the data from Web of Science repository (https://apps.webofknowledge.com/) in December 2017–January 2018. The data have been filtered using the Advanced Search tool

*TS* = (*topic* 1) *AND TS* = (*topic* 2) (1)

In our queries, we used as topic 1 "graphene" or "graphene oxide" or "graphene-related material," combined with the following keywords as topic "medicine," "biomaterials," "scaffold," "regenerative medicine," or "bioengineering." Then all the data sets obtained were merged with the "Combine Sets" tool. As a result, we obtained a dataset in .txt format containing a list of 1208 articles with their attributes. All the following analyses have been carried

hypoxia and ROS generation in these areas [15].

human body and fluids) are still incomplete.

**2. Materials and methods**

**2.1. Data collection and dataset**

with the following syntax:

out on this data set:

tries that are more involved in this research activity.

where *TS* is the topic; *AND* is the Boolean operator.

potential use [7].

Graphene oxide has shown great potential enhancing differentiation and proliferation of human stem cells in vitro, which tend to adhere to graphene plates. In particular, it favors differentiation of human neuronal stem cells (hNSC) toward neurons rather than glia cells [2]. Combined with its inherent flexibility and strength, the possibility of creating a 3D structure that mimics the original organ, graphene appears to be a great scaffold for stem cell-based therapy [3].

Furthermore, a lot of research has come forward regarding the use of graphene in biosensors. Compared to previously used materials, graphene shows increased resistance and sensitivity. Also, being biocompatible it can be worn, allowing for the possibility of a permanently used sensor. Additionally, graphene can be bound to a wide range of molecules and proteins that allow for better selectivity [4].

Another field to which graphene's ability to be bound to specific molecules has been applied is drug carrying and delivery. In particular, it has been successfully used for specific anticancer drug delivery [5]. It presents novel perspective in combining site detection and drug delivery. Peptides bound to the GO plates allow for detection by specific cell types, minimizing uptake by other healthy cells [6].

Graphene's use in the medical field raises a lot of questions regarding its safety and toxicity. In this regard, there are many conflicting studies and opinions. It appears that the matter of toxicity varies greatly depending on the physicochemical characteristics of the administrated graphene, also on the form of administration, and the model, varying between different species and cell types. The characteristics of graphene like concentration, dimensions (lateral and number of layers), surface structure functional groups, and protein corona influence its toxicity in biological systems. Despite its relevance to the effect, some toxicological studies do not give a proper characterization of the form of graphene used. Though most agree on the interaction of graphene with the cellular membrane, the question of its uptake is more controversial [7]. For example, the studies of Yue et al. on the viability of six different cell lines when treated with GO of varying dimensions show that only two phagocytic cell lines were able to internalize both nano- and micro-sized GO sheets. Furthermore, there was no difference in the viability of any of the six cell line studies when the concentration was lower than 20 μg/mL. On the other hand, inhalation of GO particles may lead to an accumulation in the pulmonary surfactant and initiate an inflammatory process [8].

Interestingly, although GO does not show to be absorbed through the gastrointestinal tract, a low dose of GO can cause more damage to the gastrointestinal surface being drank as a suspension than a high dose of GO [9]. Most toxic effects seem to surge from the use of high doses of GO and the sequential aggregation and formation of conglomerates than can block small blood vessels and result in dyspnea [10]. However, recent publications detect no pathological effects in mice exposed to low dosages of GO and functionalized graphene when administrated by intravenous injection [11].

While studying toxicity it is very important to analyze the effect on the reproductive system and development because this can lead to more lasting effects. Graphene plaques seem unable to penetrate the blood-testis barrier in mice, and therefore sperm function and male reproductive activity show no alteration even for high doses of graphene [12]. In the female, there are no alterations if GO is administered before mating or during early gestation, and the female can give birth to healthy litters. However, if administered during late gestation, it leads to abortion and even death of the pregnant mice for high dose [13]. Injection of chicken eggs leads to reduced vascularization of the heart [14]. Despite showing no obvious malformation or mortality in zebrafish embryo, GO aggregates were retained in many organelles leading to hypoxia and ROS generation in these areas [15].

Even though graphene toxicity has drawn a lot of attention from scientists, there is a remarkable lack of understanding of the mechanisms underlying this effect. The use of different models and forms of graphene seem to lead to very dissimilar conclusions. There is a clear need for more systematic and in-depth studies, before graphene can be brought to its full potential use [7].

In this context, it is evident that, in one hand, graphene and graphene-related materials are even more used in medicine and bioengineering; on the other one, the information about their safety, their toxicity, and about the way of their possible interaction with living being (and human body and fluids) are still incomplete.

For this reason, here, we carried out a scientometric study on this very interesting topic, with the aim to study the scientific literature and to identify the most relevant topic and the countries that are more involved in this research activity.
