This review article summarizes the latest progress in research regarding bioapplications of graphene oxide derivatives and provides expert opinions on strategies for overcoming the current challenges.
Exosomes are cell-derived vesicles containing heterogeneous active biomolecules such as
proteins, lipids, mRNAs, receptors, immune regulatory molecules, and nucleic acids. They
typically range in size from 30 to 150 nm in diameter. An exosome’s surfaces can
be bioengineered with antibodies, fluorescent dye, peptides, and tailored for small
molecule and large active biologics. Exosomes have enormous potential as a drug delivery
vehicle due to enhanced biocompatibility, excellent payload capability, and reduced
immunogenicity compared to alternative polymeric-based carriers. Because of active
targeting and specificity, exosomes are capable of delivering their cargo to
exosome-recipient cells. Additionally, exosomes can potentially act as early stage
disease diagnostic tools as the exosome carries various protein biomarkers associated
with a specific disease. In this review, we summarize recent progress on exosome
composition, biological characterization, and isolation techniques. Finally, we outline
the exosome’s clinical applications and preclinical advancement to provide an
outlook on the importance of exosomes for use in targeted drug delivery, biomarker
study, and vaccine development.
The combined delivery of photo- and chemo-therapeutic agents is an emerging strategy to overcome drug resistance in treating cancer, and controlled light-responsive drug release is a proven tactic to produce a continuous therapeutic effect for a prolonged duration. Here, a combination of light-responsive graphene, chemo-agent doxorubicin and pH-sensitive disulfide-bond linked hyaluronic acid form a nanogel (called a graphene-doxorubicin conjugate in a hyaluronic acid nanogel) that exerts an activity with multiple effects: thermo and chemotherapeutic, real-time noninvasive imaging, and light-glutathione-responsive controlled drug release. The nanogel is mono-dispersed with an average diameter of 120 nm as observed by using TEM and a hydrodynamic size analyzer. It has excellent photo-luminescence properties and good stability in buffer and serum solutions. Graphene itself, being photoluminescent, can be considered an optical imaging contrast agent as well as a heat source when excited by laser irradiation. Thus the nanogel shows simultaneous thermo-chemotherapeutic effects on noninvasive optical imaging. We have also found that irradiation enhances the release of doxorubicin in a controlled manner. This release synergizes therapeutic activity of the nanogel in killing tumor cells. Our findings demonstrate that the graphene-doxorubicin conjugate in the hyaluronic acid nanogel is very effective in killing the human lung cancer cell line (A549) with limited toxicity in the non-cancerous cell line (MDCK).
Because of the superiority of GQDs (graphene quantum dots) in biomedical imaging, in terms of biocompatibility and toxicity of semiconductor quantum dots, GQDs bring new opportunities for the diagnosis and detection of diseases. In this study, we synthesized photoluminescent (PL) graphene quantum dots (GQDs) through a simple exfoliation and oxidation process, and then coated them with polydopamine (pDA) for enhanced stability in water and low toxicity in vivo. From the results, the GQDs coated with pDA showed an excellent stability of PL intensity. It showed that the PL intensity of noncoated GQDs in PBS solution rapidly decreased with time, resulting in a 45% reduction of the PL intensity for 14 days of incubation in PBS solution. After coating with polydopamine, PL intensities of polydopamine-coated GQDs was maintained more stably for 14 days compared with uncoated GQDs. We have observed the in vitro and in vivo biocompatibility of pDA-coated GQDs in nude mice. The overall observation revealed that pDA-coated GQDs could be used as a long-term optical imaging agent as well as a biocompatible drug carrier.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.