Wound healing is a highly specialized multi-step process for repairing damaged or injured tissues.1 A failure in normal wound healing leads to a chronic state susceptible to infection, or abnormal scar formation. It is important to effectively manage chronic wounds as it could affect an individual’s quality of life and could significantly increase the financial burden of healthcare systems.
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Among varied nanomaterials with antimicrobial properties, carbon materials-based quantum dots (CQDs) have exhibited higher competence in wound healing due to their unique properties, such as low cytotoxicity, and uniform dispersibility in aqueous solutions.2
QDs: Properties and benefits
QDs are the first nanoscale semiconductor crystals discovered in 1981 by Ekimov and Onushenko from heavy metals. These are zero-dimensional nanoparticles, which have been widely explored in biomedical research because of their unique mechanical properties, small size ranging between 4 and 12 nm in diameter, self-luminescence, and photochemical stability.3
CQDs are the new generation of QDs that have exhibited superior qualities over traditional QDs, particularly in terms of biocompatibility, and photoluminescence.4 Compared to traditional QDs, CQDs have exhibited low toxicity, excellent chemical stability, high photostability, and resistance to photobleaching.
Besides the mechanical, optical, and physicochemical properties, other advantages of using CQDs for large-scale biomedical products are cost-effectiveness because of their abundant eco-friendly sources, and simple production processes.
Why are QDs applied in wound healing?
In wound healing, QDs are more favorable compared to many commonly used nanomaterials with antibacterial properties, such as silver nanomaterials, because of their high quantum yield (QY) of fluorescence, photostability, and extremely narrow emission band.5 QDs exhibit significant antibacterial properties that are extremely beneficial in healing wounds.
QDs are involved in a signaling pathway that leads to an increase in the interleukin-6 expression, thereby, improving the inflammation phase of wound healing. This activity has been attributed to their small size, which increases electron mobility between valence and conduction bands. The low cytotoxicity and enzymatic functions (e.g., oxidase, peroxidase, and catalase) of QDs are also associated with their size and low molecular weight.
Another important property of QDs is their ability to enhance the mechanical strength of hydrogels and tissue scaffolds, which support wound healing. The large surface area of QDs enhances their capacity to bind the ligands that are involved in the wound healing process.5
Compared to inorganic QDs, CQDs are more commonly used in wound healing because they contribute to angiogenesis by increasing the expression of anti-angiogenic factors, which helps prevent the excessive expression of pro-angiogenic factors.
Antimicrobial mechanisms of QD types and benefits in wound healing
Many studies have highlighted the antibacterial activity of QDs against common multidrug-resistant (MDR) pathogens, such as Pseudomonas aeruginosa, Staphylococcus aureus, Acinetobacter baumannii, Mycobacterium tuberculosis, Listeria monocytogenes, Streptococcus mutans, and Campylobacter jejuni.6 This antibacterial activity has been attributed to varied mechanisms of action including disruption of cell wall or cell membrane of a microbial pathogen, generation of reactive oxygen species (ROS), and DNA damage. The inhibitory action on microbial pathogens depends on the size, shape, and surface chemistry of QDs.
The high antimicrobial activity of CQDs has been attributed to their crystallographic structure, catalytic activity, charge transfer, and functionalized state. Different CQD composites, such as metal-containing CQDs, nitrogen-doped CQDs, antibiotic-conjugated CQDs, and photoresponsive CQDs, have been designed for antimicrobial therapy. For example, CQD-nitric oxide (NO), has been used in healing burn wounds because it promotes the vascularization and epithelialization of the wound through sustained release of NO.7
CQDs are highly beneficial for wound treatment because of their capacity to accelerate the healing of infected wounds by inhibiting bacterial infection, enhancing cell migration of fibroblasts, accelerating collagen deposition, regulating immunoreaction, and promoting angiogenesis. Considering these benefits, CQDs have been used to alleviate chronic and infectious wounds, for many years.
Research highlights the scope of CQDs in smart wound healing strategies
Smart sensors embedded in wound dressing can provide a non-invasive, real-time evaluation of various wound parameters including moisture levels, temperature, and various biomarkers. Many studies have shown that wound healing is directly associated with the pH of the wound environment, i.e., pH transitions from alkaline to neutral to acidic during healing.
CQDs have amino or carboxyl groups on their surfaces that respond to pH changes, altering fluorescence intensity. With real-time, remote signal assessment via smartphones, clinicians can continuously monitor wound status and provide timely treatment.
Scientists have recently developed PEI-EDTA-2Na carbon quantum dots (PECDs) via a hydrothermal method.8 PECDs are pH-responsive and can eliminate bacteria in weakly acidic conditions by disrupting DNA and proteins. After the bacterial infection resolves, PECDs adjust to neutral and alkaline environments. Subsequently, they scavenge ROS, promote macrophage polarization, reduce inflammation, and accelerate wound healing.
The intrinsic fluorescing property of PECDs enables real-time pH monitoring of wounds. Therefore, it can be used as a non-invasive diagnostic tool to determine wound status. Owing to its dual role in diagnostics and therapeutics, PECDs can be used as a versatile platform for smart wound management.
Recently, scientists developed a wound-healing dressing by electrospinning a biodegradable nanofiber scaffold made from a blend of natural and synthetic polymers. CQDs were then incorporated to enhance its healing capabilities. Studies in animal models have shown promising effectiveness.9
Researchers have also recently created a chitosan-graphene quantum dot-based active film as a smart wound dressing. For this smart wound dressing, graphene quantum dots (GQDs) were selected due to their superior biocompatibility, high mechanical strength and stability; and chitosan for its high biocompatibility, antibacterial and inflammatory properties. These chitosan-graphene quantum dots films were found to be flexible, well structured, promoted cell migration, had significant antibacterial activity, regulated wound moisture, and exhibited lower hemolytic activity.
Future outlook
Considering the dual role in diagnosis and therapy, in the future, more CQD composites could be explored for smart wound management. More research is required to better understand the underlying mechanisms of QDs in wound healing. Long-term observational studies are required to assess the potential side effects of different QDs in wound healing applications. In the future, researchers could also explore how varied QD sizes influence wound healing differently.
References
- Kolimi P, et al. Innovative Treatment Strategies to Accelerate Wound Healing: Trajectory and Recent Advancements. Cells. 2022;11(15):2439. doi: 10.3390/cells11152439.
- Pormohammad A, et al. Nanomaterials in Wound Healing and Infection Control. Antibiotics (Basel). 2021;10(5):473. doi: 10.3390/antibiotics10050473.
- Matea CT, et al. Quantum dots in imaging, drug delivery and sensor applications. Int J Nanomedicine. 2017;12:5421-5431. doi: 10.2147/IJN.S138624.
- Le N, Kim K. Current Advances in the Biomedical Applications of Quantum Dots: Promises and Challenges. Int J Mol Sci. 2023;24(16):12682. doi: 10.3390/ijms241612682.
- Salleh A, Fauzi MB. The In Vivo, In Vitro and In Ovo Evaluation of Quantum Dots in Wound Healing: A Review. Polymers (Basel). 2021;13(2):191. doi: 10.3390/polym13020191.
- Zare I, et al. Antimicrobial carbon materials-based quantum dots: From synthesis strategies to antibacterial properties for diagnostic and therapeutic applications in wound healing. Coordination Chemistry Reviews. 2025; 522, 216211. doi.org/10.1016/j.ccr.2024.216211
- Tang T, et al. Carbon quantum dots as a nitric oxide donor can promote wound healing of deep partial-thickness burns in rats. Eur J Pharm Sci. 2023;183:106394. doi: 10.1016/j.ejps.2023.106394.
- Qi W, et al. Multifunctional Carbon Quantum Dots for Monitoring and Therapy of Bacterial Infected Wounds. Adv Healthc Mater. 2025; e2403670. doi: 10.1002/adhm.202403670.
- Partovi A, et al. Electrospun nanofibrous wound dressings with enhanced efficiency through carbon quantum dots and citrate incorporation. Sci Rep. 2024;14(1):19256. doi: 10.1038/s41598-024-70295-9.
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