As shown in Fig. 12.3A, the XRD is utilized to evaluate the degree of crystallinity of the manufactured materials. In Fig. 12.3B, we have a representation of the particle

Graphene nanosheets’ aquaphobic and van der Waals connections with the sEV lipid bilayer make them favorable drug transporters for intercalation [55]. Easy adsorption of hydrophobic pharmaceuticals is made possible by graphene’s delocalized elec­tron, and hydrophilic medications can be effectuated completely onto the material. Despite this, graphene drug carriers frequently become imprisoned within the bilayer, never reaching the interior. Recent research [56–58] identified interaction based on chirality between the sheets of graphene and the lipid molecules as a putative mech­anism allowing this concluding passage into the interior of the sEVs. Chirality is a fundamental property of all living organisms, [59] making it an important factor in the biomedical uses of nanoparticles (NPs) involving cellular absorption, immuno­logical response, and tissue transport [60]. Because of their low cytotoxicity, great biocompatibility [61], optical characteristics [25], and finely controlled properties related to physical and chemical, GQDs have found widespread use in biomedical applications [62]. Specifically, the zero-dimensional (0D) architecture, nanoscale dimensions, and chemical structure [63] of GQDs enabled them to exhibit excellent passive transport properties via cellular lipid membranes [61]. Furthermore, GQDs can efficiently transport a wide variety of pharmaceuticals (>90%) through pi loading and van der Waals connections; these drugs can be chemical, hydrophilic, biological, or hydrophobic [31, 64]. Since sEVs have lipid bilayers comparable to their parent cells’ membranes, one that is right-handed and chiral could be a useful tool for efficiently loading drugs/genes into sEVs via passive transport [65, 66]. Successful production of a GQD dispersion was observed, with particles ranging in size from 2–7 nm and emitting vivid yellow photoluminescence (PL, Fig. 12.5). EDC/NHS cross-connecting method was used to covalently fix L-cysteine/D-cysteine moieties to the boundaries of the carbon pieces; [67]Fig.12.5a denotes L- and D-GQDs, which are the corresponding products. TEM scans demonstrate that unmodified and modified GQDs have a similar size distribution in the 2–7 nm range (Fig. 12.5b,c) [68]. PL spectra also undergo spectral shifts simultaneously. Robust release at 520– 550 nm is seen in the pristine, L, and D-forms of GQDs when they are stimulated by photons with ex = 330 nm (Fig. 12.5d–f).

Among the known loading technologies, the minimum invasive is incubation as a passive method of exogenous loading of medicines and harvested sEVs [69]. Passive loading effectiveness of soluble medicines is typically below 10% without the conjugation of hydrophobic moieties [70, 71]. Medication loading efficiencies of 66.3% and 64.1% for siRNA and DOX were achieved by optimizing the GQD size and ligands to maximize their chirality [58]. They initially produced chiral GQDs resulting from surface change with L/D-cysteine (L- and D-CysGQDs) using a formerly published approach to study the penetration efficiency of chiral GQDs into sEVs (Fig. 12.6a,b). L- and D-CysGQDs were found to have a distribution of sizes of 3.0–9.4 nm, as observed in images in TEM (Fig. 12.6c). The size variety of L- and D-Cys-GQDs in TEM was authenticated by AFM pictures (Fig. 12.6d). The AFM results (Fig. 12.6d) established that the thickness of L- and D-Cys-GQDs were within 2 nm, which is reliable with a layer of chiral GQDs with improved height due to helical clasping (twisting) of the pristine GQDs (1 nm). Positive and negative peaks at 236 nm were seen in the L- and D-CysGQDs CD spectra, respectively (Fig. 12.6e). In addition, they exhibited some loosening of exciton confinement[56]. Charge trans­port between the graphene carbon core and functional groups of GQDs narrows the band gap [72, 73], causing a redshift of 26 nm. Confocal microscopy revealed that

any sample (Fig. 12.7d). A control group of sEVs with conventionally sonicated Dox was also created. Confocal fluorescence microscopy (Fig. 12.7c) demonstrated that conventional sonication (14.5 7.9%) stacks poorly. D-Cys-GQD drug loading did not significantly change sEV size or cell integrity. They treated 3T3 cells with sEVs­Dox for 24 h in vitro and compared them to a control group treated with free Dox to determine if they could take up D-Cys-GQDs/Dox-loaded sEVs. Dox is thought to exert its impacts via the embolism of DNA and protein-DNA interactions in repli­cation and transcription [74]. Dox signals (red) in confocal images showed that Dox molecules entered cells and aggregated in the nucleus (Fig. 12.7e). D-Cys-GQDs (blue) were mostly in the cytoplasm of cells, showing that Dox was released from the complex without a drug release mechanism. These benefits enable compact and