Graphene, made of carbon atoms arranged in a hexagon lattice structure, has captured the attention and fascination of scientists and researchers due to its unique structural and physiochemical attributes. Its two-dimensional planar structure grants it a remarkably large surface area on both sides of its planar axis, facilitating extensive interactions with other molecules. The graphene family encompasses materials such as few-layer graphene, graphene oxide (GO), reduced graphene oxide (rGO), and graphene nanosheets, each with distinct characteristics based on their chemical modifications and thickness. Among them, GO has gained significant attention in biomedical applications due to its amphiphilic nature, allowing for stable dispersion in aqueous environments—a key feature in biomedical contexts.
One of the most attractive features of graphene-based materials is their large surface area, which can be utilized for molecular loading in drug delivery systems, biosensors and tissue engineering scaffolds. Compared with other carbon-based nanomaterials like carbon nanotubes, graphene demonstrates superior dispersibility in most solvents, including biological fluids. This is particularly true of graphene oxide, where polar functional groups such as hydroxyl, carboxyl and epoxy moieties enable the formation of stable colloidal suspensions through hydrogen bonding with water molecules. This trait greatly improves the potential of GO in biomedical applications, as its stability in solution is crucial for biological compatibility and functionality.
Graphene's immense mechanical strength, high electrical conductivity, and flexibility further make it a versatile medium for use in healthcare endeavors. Its electrical properties, for instance, have been engaged in the development of cutting-edge biosensors for detecting minute concentrations of biomarkers in bodily fluids. Additionally, the material’s ability to form functional hybrids with various biomolecules has opened the door to novel applications in drug delivery, where graphene-based systems can facilitate controlled and targeted release of therapeutic agents.
A significantly promise of graphene-based nanomaterials resides in the field of drug delivery, especially in oncology. Owing to its extensive surface area and ability to undergo surface functionalization, GO can be modified with targeting ligands and therapeutic molecules to create a highly efficient vehicle for drug delivery. With its ability to interact with water-soluble drugs and biomolecules, GO can be used to create nanoscale drug delivery systems that exhibit high loading efficiency and controlled release profiles.
For cancer therapy, GO has shown remarkable potential as a drug carrier capable of delivering anticancer agents to specific tumor sites. Functionalization of GO with polyethylene glycol, for example, increases its biocompatibility with reducing immune recognition, allowing the drug-loaded nanocarrier to circulate in the bloodstream for longer periods. Targeting molecules such as antibodies or peptides, can be conjugated to the surface of GO, facilitating the selective delivery of chemotherapeutic agents to cancer cells while minimizing off-target effects to surrounding tissue. Furthermore, GO’s ability to respond to stimuli such as pH or temperature can be harnessed for controlled drug release, making it a powerful agent for precision medicine.
Studies have demonstrated that graphene-based materials exhibit bactericidal effects, particularly against Gram-negative bacteria like E. coli. GO’s antimicrobial mechanism is understood to involve several factors, including direct physical interaction with bacterial membranes and the induction of oxidative stress. GO’s sharp edges and high surface reactivity allow it to pierce bacterial cell membranes, leading to loss of membrane integrity and cell death. Additionally, GO can trigger the production of reactive oxygen species, which contribute to oxidative stress and further damage to bacterial cells. This dual action—physical disruption of the membrane and oxidative damage—makes GO a potent antimicrobial agent. Furthermore, GO's bactericidal efficiency can be tuned by altering its physicochemical properties, such as the degree of oxidation or functional group density, allowing for the development of customizable antimicrobial materials.
Given the growing threat of antibiotic resistance, graphene-based antimicrobial coatings for medical devices and implants represent a promising avenue for reducing hospital-acquired infections. By incorporating GO into wound dressings, catheters, or surgical tools, it may be possible to inhibit the growth of harmful bacteria and prevent the spread of infection without relying on conventional antibiotics.
Graphene and its derivatives have also been explored as scaffolds in tissue engineering and regenerative medicine due to their mechanical strength, biocompatibility, and ability to promote cellular interactions. Graphene-based scaffolds can mimic the extracellular matrix, providing structural support to cells and encouraging their growth and differentiation. Moreover, graphene's electrical conductivity has been found to promote the regeneration of electrically excitable tissues, such as nerve and muscle tissue.
In bone regeneration, GO has been incorporated into composite scaffolds to enhance osteogenic differentiation, aiding in the healing of bone defects. Similarly, GO has been used in skin tissue engineering to create wound dressings that not only promote tissue repair but also possess antimicrobial properties to prevent infection. The integration of graphene-based materials into tissue engineering offers exciting possibilities for developing bioactive, multifunctional scaffolds that accelerate the healing process and improve patient outcomes.
Graphene and its derivatives represent a new frontier in biomedical science. While the field is still in its relative nascent stage compared to other nanomaterials, its unique properties—large surface area, mechanical strength, electrical conductivity, and versatility in functionalization—show promise as a candidate for addressing some of the most pressing challenges in modern medicine. As research into graphene evolves, their integration into healthcare systems will usher in a new era of state-of-the-art, multifunctional biomedical technologies.