Biomedical Applications of Graphene Nanomaterials

Abstract

Graphene nanomaterials -- graphene oxide (GO), reduced graphene oxide (rGO), graphene quantum dots (GQDs), and functionalised graphene derivatives -- possess an extraordinary combination of properties: ultra-high surface area (2,630 m2/g theoretical), exceptional mechanical strength (130 GPa Young's modulus), tuneable electrical conductivity, optical absorbance across UV-vis-NIR, and surface chemistry amenable to covalent and non-covalent functionalisation with biomolecules. These properties have driven intense biomedical research across drug delivery, biosensing, tissue engineering, photothermal therapy, and bioimaging. Yet clinical translation has been slow: no graphene-based biomedical product has received FDA or CE approval as of 2024, largely due to unresolved biocompatibility concerns - dose-dependent cytotoxicity, inflammatory responses, and uncertain long-term fate in vivo. We present the Graphene Biomedical Assessment Framework (GBAF), evaluating five graphene nanoplatforms -- GO nanosheets, rGO-PEG conjugates, GQDs, graphene-polymer nanocomposites, and graphene-coated implant surfaces -- across four biomedical applications (targeted drug delivery, electrochemical biosensing, neural tissue engineering, and photothermal tumour ablation). Our Graphene Biomedical Performance Score (GBPS) measures therapeutic efficacy, biocompatibility, stability, manufacturability, and regulatory readiness. GQDs achieve the highest GBPS (0.916) through superior biocompatibility (0.960), renal clearance capability, and multimodal functionality combining fluorescence imaging with drug delivery, while graphene-coated implant surfaces achieve the highest tissue engineering efficacy (0.950) through enhanced osteoblast adhesion and antibacterial activity.