Natural carbon-based quantum dots and their applications in drug delivery: A review

Graphical abstract

Various NCDs with antimicrobial, anticancer and neurodegenerative drug delivery applications. a) Pleurotus species, b) Hylocereus undatus, c) Curcuma longa L., d) Manilkara zapota (L.) P. Royen, e) Banana leaf, f) Carica papaya, g) Ocimum Sanctum, h) Foeniculum vulgare Mill seeds, i) Azadirachta indica, j) Aloe vera (L.) Burm.f.

Highlights

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  The source and rationale behind natural carbon quantum dots (NCDs) are carefully discussed.

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  The various synthesis method and their merits have been summarized.

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  The optical properties and toxicological profile of NCDs are highlighted.

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  The drug delivery applications of NCDs are detailed.

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  The clinical status of NCDs are presented.

Abstract

Natural carbon based quantum dots (NCDs) are an emerging class of nanomaterials in the carbon family. NCDs have gained immense acclamation among researchers because of their abundance, eco-friendly nature, aqueous solubility, the diverse functionality and biocompatibility when compared to other conventional carbon quantum dots (CDs).The presence of different functional groups on the surface of NCDs such as thiol, carboxyl, hydroxyl, etc., provides improved quantum yield, physicochemical and optical properties which promote bioimaging, sensing, and drug delivery. This review provides comprehensive knowledge about NCDs for drug delivery applications by outlining the source and rationale behind NCDs, different routes of synthesis of NCDs and the merits of adopting each method. Detailed information regarding the mechanism behind the optical properties, toxicological profile including biosafety and biodistribution of NCDs that are favourable for drug delivery are discussed. The drug delivery applications of NCDs particularly as sensing and real-time tracing probe, antimicrobial, anticancer, neurodegenerative agents are reviewed. The clinical aspects of NCDs are also reviewed as an initiative to strengthen the case of NCDs as potent drug delivery agents.