Insight into carbon quantum dot-vesicles interactions: role of functional groups

Area of Science:

• Nanomaterials Science
• Biotechnology
• Surface Chemistry

Background:

• Understanding nanoparticle-cell membrane interactions is vital for effective drug delivery systems.
• Carbon quantum dots (CQDs) show promise as drug carriers, but their interaction with cell membranes needs detailed study.

Purpose of the Study:

• To investigate the interaction between different functionalized CQDs and model cell membranes (phosphatidylcholine vesicles).
• To identify the specific functional groups on CQDs that promote strong membrane binding for potential drug delivery applications.

Main Methods:

• Utilized photoluminescence (PL) behavior, vesicle surface charge analysis, quartz crystal microbalance (QCM), isothermal titration calorimetry (ITC), transmission electron microscopy (TEM), linear sweep voltammetry (LSV), and Fourier-transform infrared spectroscopy (FTIR).
• Compared interactions of four types of CQDs: -COOH, -NH2, -OH, and bovine serum albumin (BSA) coated.

Main Results:

• Carbon quantum dots functionalized with amine (-NH2) groups exhibited strong binding affinity with phosphatidylcholine vesicles.
• Other functionalized CQDs showed significantly weaker interactions with the model membrane.
• TEM imaging confirmed the enhanced interaction of amine-functionalized CQDs (PEICD) with vesicles.

Conclusions:

• The -NH2 functional group on carbon quantum dots significantly enhances their interaction with model cell membranes, likely through hydrogen bonding.
• These findings provide mechanistic insights for designing efficient carbon-based nanomaterials for targeted drug and gene delivery.
• The study highlights the relevance of such nano-bio interface interactions, drawing parallels with natural biological processes like neurotransmitter transport.