Graphene and graphene oxide as nanomaterials for medicine and biology application

Graphene has unique mechanical, electronic, and optical properties, which researchers have used to develop novel electronic materials including transparent conductors and ultrafast transistors. Recently, the understanding of various chemical properties of graphene has facilitated its application in high-performance devices that generate and store energy. Graphene is now expanding its territory beyond electronic and chemical applications toward biomedical areas such as precise biosensing through graphene-quenched fluorescence, graphene-enhanced cell differentiation and growth, and graphene-assisted laser desorption/ionization for mass spectrometry. In this Account, we review recent efforts to apply graphene and graphene oxides (GO) to biomedical research and a few different approaches to prepare graphene materials designed for biomedical applications. Because of its excellent aqueous processability, amphiphilicity, surface functionalizability, surface enhanced Raman scattering (SERS), and fluorescence quenching ability, GO chemically exfoliated from oxidized graphite is considered a promising material for biological applications. In addition, the hydrophobicity and flexibility of large-area graphene synthesized by chemical vapor deposition (CVD) allow this material to play an important role in cell growth and differentiation. The lack of acceptable classification standards of graphene derivatives based on chemical and physical properties has hindered the biological application of graphene derivatives. The development of an efficient graphene-based biosensor requires stable biofunctionalization of graphene derivatives under physiological conditions with minimal loss of their unique properties. For the development graphene-based therapeutics, researchers will need to build on the standardization of graphene derivatives and study the biofunctionalization of graphene to clearly understand how cells respond to exposure to graphene derivatives. Although several challenging issues remain, initial promising results in these areas point toward significant potential for graphene derivatives in biomedical research.

In this review paper, the ill effects of pharmaceuticals (PhAs) on the environment and their adsorption on graphene oxide (GO) and graphene oxide-based (GO-based) nanomaterials have been summarised and discussed. The adsorption of prominent PhAs discussed herein includes beta-blockers (atenolol and propranolol), antibiotics (tetracycline, ciprofloxacin and sulfamethoxazole), pharmaceutically active compounds (carbamazepine) and analgesics such as diclofenac. The adsorption of PhAs strictly depends upon the experimental conditions such as pH, adsorbent and adsorbate concentrations, temperature, ionic strength, etc. To understand the adsorption mechanism and feasibility of the adsorption process, the adsorption isotherms, thermodynamics and kinetic studies were also considered. Except for some cases, GO and its derivatives show excellent adsorption capacities for PhAs, which is crucial for their applications in the environmental pollution cleanup.

Biomedical applications of graphene have recently attracted intensive attention, with graphene-based nanomaterials being reported as promising candidates in, for example, drug delivery, biosensing and bioimaging. In this paper, mechanical properties and bioactivity of nanofibrous and porous membranes electrospun from graphene oxide (GO) nanoplatelets reinforced poly(ε-caprolactone) (PCL) were investigated. The results showed that the presence of 0.3 wt% GO increased the tensile strength, modulus and energy at break of the PCL membrane by 95%, 66% and 416%, respectively, while improving its bioactivity during biomineralization and maintaining the high porosity of over 94%. The mechanical enhancements were ascribed to the change in the fiber morphology and the reinforcing effect of GO on PCL nanofibers, whereas the improvements on the bioactivity stemmed from the anionic functional groups present on the GO surface that nucleated the formation of biominerals. Systematic studies on the PCL/GO nanocomposite films with varying GO concentrations revealed that the reinforcing effect of GO on PCL was due to the strong interfacial interactions between the two phases characterized by Fourier transform infrared spectroscopy, the good dispersion of GO in the matrix and the intrinsic properties of GO nanoplatelets. The strong and bioactive PCL/GO nanofibrous membranes with a high porosity have great potential for biomedical applications.

Graphene exhibits unique 2-D structure and exceptional phyiscal and chemical properties that lead to many potential applications. Among various applications, biomedical applications of graphene have attracted ever-increasing interests over the last three years. In this review, we present an overview of current advances in applications of graphene in biomedicine with focus on drug delivery, cancer therapy and biological imaging, together with a brief discussion on the challenges and perspectives for future research in this field.

Since the birth of graphene in 2004, it has attracted great research interests of scientists. As the first true two-dimensional (2D) material, graphene has many advantages, such as large specific surface area, high intrinsic carrier mobility, strong mechanical strength, and superior flexibility. Graphene shows broad application prospects. As an important functionalized material, graphene oxide (GO) is 2D macromolecule rich in oxygen-containing functional groups. It has good hydrophilicity and is widely used as a chemical functionalized material in many related fields and applied to energy conversion and storage devices. However, converting the ideal properties of graphene and its derivatives into macrostructures or devices remains a challenge for scientists. The strong interaction between graphene sheets leads to their easy stacking, which greatly reduces their specific surface area and severely limits their efficient use of interfaces. Therefore, the applications of graphene in electronic devices, catalysis, energy storage and other fields have been greatly limited. The key to improve the performance of graphene is how to effectively prevent the stacking of graphene sheets. The assembly and processing of graphene with specific micro-/nano-morphology is conducive to better play the expertise of graphene, thus effectively enhancing the performance of graphene based devices. In this regard, there are lots of efforts have been devoted to the design of structure and morphology for graphene based materials. In the field of water-induced graphene energy converters, the interaction between water molecule and graphene is affected more by the morphology and microstructure change of graphene. As a new type of nano-material, graphene assembly can further expand its application scope. Due to the popularity of portable, flexible and wearable electronic devices, graphene materials have attracted a great deal of research interest from researchers in the field of energy converters. Graphene fibers and films are good solutions for portable needs. Graphene foam with compressibility also has important application value. In the field of hydropower, the moisture induced power generation of graphene oxide, most importantly, the construction of oxygen-containing radical gradients and the entry of water molecules. In a wet environment, water molecules can cause positive and negative charge separation, so that the potential difference appears on both sides of the material, resulting in the conversion of chemical potential energy into electrical energy. Moisture responds to the driver, depending on the affinity between the water and the GO layer. Water evaporation depends on the interaction between water molecules and carbon nanolayers. In this review, we summarized the current work of the major research teams at home and abroad on the assembly and processing of graphene, and the related work of graphene-based carbon materials in water-induced energy conversion, including the assembly and processing of graphene microstructures. As well as moisture power generation, moisture response drivers and water evaporation power generation, this will have guiding significance for the research of other types of materials in hydroelectric power generation. In the future, we still need to work hard in constructing the concentration and gradient of material functional groups to try to find out the actual applied electrical energy. In addition, many current carbon-based materials generate relatively low currents, and current researches on current increase are still continuing so that they can be applied in real life. Moreover, the interaction between carbon materials and water produces electricity. The mechanism still needs to be further explored, which will lay the foundation for future research on the production of electricity from other materials.

Computer simulation of cell entry of graphene nanosheet

Carbon Nanotubes and Graphene

The remarkable physicochemical properties of Graphene oxide (GO), a graphene derivative, have made it a material with intriguing medical administration potential. Its 2D allotropic nature is the source of its biological flexibility. The transportation of genes and small molecules are just two of the many biomedical applications of graphene and its composite. Antibacterial use in tooth and bone grafts, biofunctionalization of proteins, and treatment of cancer are among other potential uses. The biocompatibility of the freshly synthesized nanomaterials opens up a world of potential biological and medicinal uses. Furthermore, GO's versatility makes it an ideal component for usage in other drug delivery systems, such as hydrogels, nanoparticles, and micelles. This review aims to compile the existing body of knowledge regarding the use of GO in drug delivery by delving into its many potential uses, obstacles, and future developments.

Graphene-based nanoprobes and a prototype optical biosensing platform

A review on exploring the impact of graphene oxide-based nanomaterials on structures and bioactivity of proteins

Biomedical applications of graphene in tumor and bacterial treatment have become cutting-edge fields due to its unique physical and chemical properties. However, a mechanistic understanding of the interactions and reactions between graphene-based material and biological systems such as lipid membranes remains elusive, especially at the molecular level. By using the unique field-induced droplet ionization mass spectrometry and cryogenic electron microscopy methodologies, we reveal the oxidation products of monolayer lipid membranes at the air-water interface and the change in the morphology of bilayer lipid membranes in an aqueous solution caused by the incorporation of graphene oxide bearing π-conjugated carbon radicals [hydrated graphene oxide (hGO)]. We discovered that hGO is an efficient source of hydroxyl radicals and that it is not only the incorporation of the hGO sheets but also the irregular packing of the lipid oxides from the hydroxyl radical oxidation that causes the structural distortions of the liposomes.

In this mini review we have demonstrated the enormous possibility of next generation electronic and biomedical applications of graphene and its derivatives (graphene oxides). Graphene and its derivatives (graphene oxide, GO, and reduced graphene oxide, rGO) are being evolved as “miracle materials” with manifold applications in different sectors of science and technology (starting from electronics, computer chips energy storage , clean water to tissue engineering in biological science).

Effects of radiation therapy on craniofacial and dental implants: a review of the literature

9 - Biomedical Applications of Graphene

This issue of Interface Focus is a collection of papers on ‘The biomedical applications of graphene’. The idea to put together this theme issue evolved during discussions between Prof. Peter N.T. Wells CBE, FREng, FMedSci, FRS and myself in mid-2016. Very sadly, about a year ago, Prof. Wells passed away. However, before that and even in the various last stages of his life he was intensely involved in planning this theme issue with me. I am deeply indebted to him for his contributions towards this and I dedicate this theme issue to him as a memorial.