Hydrothermal Synthesis of Carbon Nanodots from Pectinodesmus sp. for Drug Delivery via Chitosan Hydrogels

Abstract

Background: Carbon nanodots (CNDs) are nanoscale carbon-based particles known for their small size (typically less than 10 nm), excellent biocompatibility, low toxicity, and strong photoluminescence. Chitosan, a biopolymer derived from chitin, is notable for its biocompatibility, biodegradability, and ability to enhance drug solubility and permeability. In drug delivery, it is possible to use CNDs as fluorescent signals for tracking the delivery process, while chitosan serves as a versatile carrier that can encapsulate drugs, facilitate their controlled release, and enhance cellular uptake due to its mucoadhesive properties. Together, they form an effective composite for targeted drug delivery systems, combining the imaging capabilities of CNDs with the drug-carrying and release properties of chitosan, potentially improving therapeutic outcomes. Methodology: Algae extract was used for the synthesis of carbon nanodots using hydrothermal method where algal biomass served as carbon precursor for the synthesis carbon nanodots. The synthesized carbon dots were studied by imaging microscopy, XRD, EDS, and FTIR in addition to scanning electron microscopy and ultraviolet-visible spectroscopy. Chitosan was mixed with 2:3 solution of acetic acid and glycerol and carbon nanodots were mixed in this solution during gelation process. The resulting gel was characterised by swelling and degradation studies and drug release studies were performed using UV-Vis Spectroscopy. Results: UV-Vis analysis revealed the distinct peak at 264nm attributed to Carbon nanodots whereas SEM analysis demonstrated the characteristic morphology of carbon nanodots with spherical shapes and some agglomeration. FTIR spectra of carbon nanodots confirmed presence of similar peaks when compared to algal strain with difference in intensity of peaks. Swelling studies suggested that with increase in concentration of carbon nanodots swelling properties are reduced. Degradation studies suggested that with gel with increased carbon nanodots concentration were less prone to degradation. Drug loading and releasing properties of hydrogel using Vancomycin as model drug were performed at different two different pH. Drug releasing properties were greatly enhanced in 2 pH conditions as compared to 7.4 pH. xiv Conclusion: The finding suggested carbon nanodots incorporated chitosan gel could be used as possible strategy for drug delivery of drugs that have poor absorptions in gastrointestinal tract.