Graphene oxide has been used in different fields of nanomedicine as a manager of drug delivery due to its inherent physical and chemical properties that allow its use in thin films with biomedical applications. Several studies demonstrated its efficacy in the control of the amount and the timely delivery of drugs when it is incorporated in multilayer films. It has been demonstrated that oxide graphene layers are able to work as drug delivery or just to delay consecutive drug dosage, allowing the operation of time-controlled systems. This review presents the latest research developments of biomedical applications using graphene oxide as the main component of a drug delivery system, with focus on the production and characterization of films, in vitro and in vivo assays, main applications of graphene oxide biomedical devices, and its biocompatibility properties.

Graphene is the material elected to study molecules and monolayers at the molecular scale due to its chemical stability and electrical properties. The invention of scanning tunneling microscopy has deepened our knowledge on molecular systems through imaging at an atomic resolution, and new possibilities have been investigated at this scale. Interest on studies on biomolecules has been demonstrated due to the possibility of mimicking biological systems, providing several applications in nanomedicine: drug delivery systems, biosensors, nanostructured scaffolds, and biodevices. A breakthrough came with the synthesis of molecular systems by stepwise methods with control at the atomic/molecular level. This article presents a review on self-assembled monolayers of biomolecules on top of graphite with applications in biodevices. Special attention is given to porphyrin systems adsorbed on top of graphite that are able to anchor other biomolecules.

Purpose: Glaucoma is the second leading cause of blindness, however, it remains incurable even with the appropriate treatment. Intraocular pressure (IOP) reduction is currently the only proven method to decline glaucoma progression. When medical therapy fails, surgical treatment usually arises as the solution to a better IOP control. Nevertheless, its success is compromised by frequent post-operative complications, most of them due to excessive fibrous tissue formation during wound healing process. Nanotechnology devices for glaucoma surgery can improve post-operative IOP control and reduce undesirable fibrosis. This systematic review aims to summarize some advances of nanotechnology application to ophthalmology, giving an overview about the state of the art of the nanotechnology based glaucoma drainage devices. Methods: A literature search in the PubMed/Medline database was performed using the keywords: “glaucoma surgery”, “glaucoma drainage device”, “nanotechnology”, “nanoparticles”, “nanomedicine” and “valve”. Were included articles published until March 1, 2023. A first identification of relevant articles was done through the title and abstract’s information, and a second selection was done by full-text articles assessment. Seven articles were included in this systematic review. Results: Nanotechnology-based glaucoma drainage devices included in this review promise to overcome the challenges of glaucoma surgical treatment by allowing a more effective control over post-operative scarring, a noninvasive and customized control of aqueous humour (AH) drainage while achieving optimal IOP reduction through all phases of the post-operative period. Conclusion: Despite the decreased post-operative complications and apparently enhanced biocompatibility of nano-based drainage devices, further in vivo tests and human studies are needed to evaluate cytotoxicity and corroborate the biocompatibility and efficacy showed in the initial testing results of these devices.

Glaucoma drainage device (GDD) surgery is frequently limited by postoperative fibro-blast proliferation, leading to device failure and the need for revision procedures. In this work, we developed a spray-assisted layer-by-layer (LbL) drug delivery system for GDD surfaces that enables localized release of antiproliferative agents, aiming to standardize patient care. Multilayer thin films composed of poly(β-amino ester) (PBAE) and a 5-fluorouracil (5-FU) and β-cyclodextrin (β-CD) complex (5-FU:β-CD) were fabricated, without (type A films) and with (type B films) graphene oxide (GO) barrier layers. Film growth was monitored by ultraviolet–visible spectroscopy (UV-Vis) and vacuum ultraviolet spectroscopy (VUV), confirming consistent, sequential deposition; type A films exhibited greater reproducibility than GO-containing type B films. Drug release studies revealed a rapid burst release within the first 5 min, fol-lowed by a plateau, regardless of GO incorporation. Cell cycle analysis confirmed that β-CD complexation preserved the biological activity of 5-FU, which induced an S-phase arrest in a dose-dependent manner. Although further optimization of film archi-tecture and composition is required to achieve sustained release, this study demon-strates the feasibility of spray-assisted LbL coatings as a localized drug delivery strate-gy for GDD surfaces. Overall, these findings establish a promising platform for the fu-ture development of more effective and standardized coatings for glaucoma surgical devices.

Glaucoma drainage device (GDD) surgery is frequently limited by postoperative fibroblast proliferation, leading to device failure and the need for revision procedures. In this work, we developed a spray-assisted layer-by-layer (LbL) drug delivery system for GDD surfaces intended to enable localized release of antiproliferative agents, as a proof-of-concept approach toward more standardized patient care. Multilayer thin films composed of poly(β-amino ester) (PBAE) and a 5-fluorouracil (5-FU) and β-cyclodextrin (β-CD) complex (5-FU:β-CD) were fabricated, without (type A films) and with (type B films) graphene oxide (GO) barrier layers. Film growth was monitored by ultraviolet–visible spectroscopy (UV-Vis) and vacuum ultraviolet spectroscopy (VUV), confirming consistent, sequential deposition; type A films exhibited lower variability than GO-containing type B films. Drug release studies revealed a rapid burst release within the first 5 min, followed by a plateau, regardless of GO incorporation, indicating that sustained drug release was not achieved under the current film architecture. Cell cycle analysis confirmed that β-CD complexation preserved the biological activity of 5-FU, which induced an S-phase arrest in a dose-dependent manner. Although further optimization of film architecture and composition is required to improve release control and achieve sustained delivery, this study demonstrates the feasibility of spray-assisted LbL coatings as a localized drug delivery strategy for GDD surfaces. Overall, these findings support the proof-of-concept nature of this approach and identify key parameters that must be optimized before translational applicability can be established.