Chirality-driven transportation and oxidation prevention by chiral selenium nanoparticles

Abstract

The chirality of nanoparticles directly influences their transport and biological effect under physiological environment, but the details of this phenomenon have rarely been explored. Herein, chiral GSH-anchored selenium nanoparticles (G@SeNPs) are fabricated to investigate the interaction between their chirality and transport and antioxidant activity. G@SeNPs modified with different enantiomers show opposite handedness with a tunable circular dichroism signal. The noninvasive positron emission tomography imaging clearly reveals that ⁶⁴Cu-labeled _L-G@SeNPs experience distinctly different transport among the major organs from their _D-and _DL-counterparts, demonstrating that the chirality of the G@SeNPs influences the biodistribution and kinetics. Taking advantage of the strong homologous cell adhesion and uptake, _L-G@SeNPs have been shown here to effectively prevent oxidation damage caused by palmitic acid in insulinoma cells. This work should motivate the biomedical applications of chiral nanomedicine by providing a fundamental understanding of chirality-dependent biodistribution and antioxidant activity.

Graphical Abstract

Chiral GSH-anchored SeNPs has been synthesized with distinct biodistribution found by positron emission tomography imaging with ⁶⁴Cu-radiolabeling. Taking advantage of homologous adhesion to the insulinoma beta cell membrane, _L-G@SeNPs effectively prevents palmitic acid-caused oxidative damage by facilitative uptake.

Tailoring the stereochemical characteristics of biomolecules is essential for developing specific physiological characteristics or behavior. In Eukarya, _D-nucleotides, _L-amino acids and _L-phospholipids are homochiral building blocks from which live organisms are formed^[1], while for baterials, _D-amino acids, i.e., _D-Ala and _D-Glu, present in the peptidoglycan on bacterial cell wall that act to provide resistance to most known proteases. Many chirality-driven medicines have been synthesized to exert distinguished therapeutic effect^[2], such as R- and S-thalidomides^[3]. The fascinating functions of chiral materials inspires tremendous amounts of research on developing functional chiral medicine, from small molecules and nanomaterials to bulk materials^[4]. Among them, nanoparticles, which process unique size and surface properties, have been considered as an ideal platform to broaden the chirality-dependent synthesis and therapeutic outcomes for chiral medicines^[5]. For instance, chiral 2D MoS₂ was fabricated by introducing the chiral ligands cysteine and penicillamine during the process of liquid exfoliation of MoS₂^[6]. Further, surface-anchored chiral molecules on nanoparticles exert different chiral preference to modulate cellular uptake and cell adhesion in either bacterial and mammaliam cells, which influence the biological effects of the nanoparticle on the cytotoxicity, autophagy, gene aditing and metabolism^[7]. Gong et al., demonstrated that the d-glutamic acid-modified graphene quantum dots showed high selective penetration into the bacterial cell membrane over mammalian cells, which displayed highly selective toxicity against microorganism and effective antimicrobial activity^[8]. Nie‘s group reported the introduction of cysteine in carbon dots and its influence on cellular energy metabolism^[9]. The Kuang team made a direct observation of the selective autophagy caused by a self-assembly nanodevice in breast cancer cells^[10]. Despite these advances in biomedical application of chiral nanomaterials, the connections between chiral nanoparticles and pharmacokinetics or cellular antioxidant ability in living organisms have not yet been fully identified. To address this challenge, a method for assembling biocompatible nanomaterials with tunable chirality is needed.

Selenium (Se) is an essential element for living organisms through taking part in important biochemical reactions, including the generation of selenomethionine, selenoxide, and _L-seryl tRNA^[11]. It is reported that the main determinant of bioavailability, toxicity and biological properties of Se lies in its chemical form, redox state and dose^[12]. Compared with Se (II), Se (IV) or Se (VI) ions, the elemental (zero-valent) Se nanoparticles, with their high Se-density formulation and unique nanoscale properties (size, shape, surface properties, solubility and chemical composition), facilitate efficient drug delivery and low toxicity in vivo and have emerged as fascinating therapeutic agents in anticancer, antimicrobial, and antioxidant treatments^[13]. In some pilot studies performed by our group, SeNPs have been coated with ligands (HER-2, transferrin, folate)^[14], synthetic polymer (Pluronic F-127 and PEG)^[15] and polysaccharide (chitosan, lentinan, Pleurotus tuber-regium)^[16 to achieve heightened tumor-targeting effect, increased biostability in vivo and controlled release in the tumor region^[17]. Herein, we report the preparation of chiral SeNPs with the addition of chiral glutathione (GSH, _L-, _D- and _DL-forms) to the surface (Figure 1a, I). Positron emission tomography (PET), which offers noninvasive and real-time monitoring of drug kinetics in vivo, was initially employed to observe the pharmacokinetics of chiral SeNPs (Figure 1a, II). We further investigated the binding of chiral G@SeNPs with the cell membrane (Figure 1 a, III) and their oxidation prevention activity against Palmitic acid (PA)-caused oxidative damage (Figure 1a, IV).

Figure 1. Design, morphology and chemical charaterization of chiral G@SeNPs for antioxidant activation.

(a) Schematic of the preparation of ⁶⁴Cu-labeled chiral G@SeNPs and antioxidant activity. I: Enantiomer structure of ⁶⁴Cu-_L-G@SeNPs, ⁶⁴Cu-_D-G@SeNPs and ⁶⁴Cu-_DL-G@SeNPs. II: PET imaging of ⁶⁴Cu-_L-G@SeNPs, ⁶⁴Cu-_D-G@SeNPs and ⁶⁴Cu-_DL-G@SeNPs in mice after intravenous injection. III: Homologous and heterologous adhesion among chiral G@SeNPs and insulinoma cell membrane. IV: _L-G@SeNPs prevented PA-caused oxidative damage by ROS scavenging. TEM images of _L-G@SeNPs (b), _D-G@SeNPs (c) and _DL-G@SeNPs (d), scale bar = 500 nm. (e) Size and zeta potential of _L-G@SeNPs, _D-G@SeNPs and _DL-G@SeNPs. The data were presented as the means ± SD, n = 3. (f) CD spectra of _L-GSH, _D-GSH, _DL-GSH, _L-G@SeNPs, _D-G@SeNPs and _DL-G@SeNPs. High resolution XPS spectra over Se 3d (g) and S 2p (h) peaks of _L-G@SeNPs, _D-G@SeNPs and _DL-G@SeNPs.

To prepare the chiral SeNPs, phycocyanin (PC), a dietary antioxidative agent extracted from Spirulina, was used to reduce Na₂SeO₃ for generating zero-valence SeNPs. Following that, _L-GSH or _D-GSH was noncovalently anchored to the surface of the SeNPs. The morphology and stability of the chiral G@SeNPs were evaluated by transmission electron microscopy (TEM), as shown in Figures 1b-1d. The morphology of _L-G@SeNPs and _D-G@SeNPs was well-dispersed with average sizes of 126.7 nm and 142.6 nm, respectively. However, the _DL-G@SeNPs (126.2 cm) were easily aggregated together. The hydrodynamic diameter of _L-G@SeNPs (227.2 nm ± 31.1 nm) was significantly smaller than that of _D-G@SeNPs (334.1 nm ± 52.3 nm) and _DL-G@SeNPs (525.8 nm ± 32.9 nm), as shown in Figure 1e. Accordingly, the zeta potential values of _L-G@SeNPs and _D-G@SeNPs were −29.5 and −25.3 mV respectively, while for _DL-G@SeNPs the potential approached neutral (−9.1 mV), suggesting a strong repulsion force among Se atoms in the single chiral nanosystem.

Circular dichroism (CD), a measurement method which rapidly characterizes the differential absorption of circularly polarized light of either handedness, was performed to characterize the chirality of the SeNPs. As shown in Figure 1f, the chiral GSH and G@SeNPs displayed vertically mirrored CD peaks with positive (right-handed) and negative (left-handed) waves in the UV region, while the racemates (_DL-GSH and _DL-G@SeNPs) showed no CD signals in the same region, demonstrating the successful chiral modification of the G@SeNPs. Moreover, the near UV area of chiral G@SeNPs showed small peaks at around 275 nm to 360 nm, which could be assigned to the aromatic amino acids (i.g., tryptophan, tyrosine), disulfides and chromophores of PC in the nanoparticles. Comparatively, the ellipticity of this peak in _D-G@SeNPs was weaker than that in _L-G@SeNPs, suggesting that the introduction of _D-GSH reduces the asymmetry of disulfide of PC, which correspondingly affects the nanoparticles’ tertiary structure.

To identify the chemical structure of the chiral G@SeNPs, X-ray photoelectron spectroscopy (XPS) was performed. From the spectrum of the Se 3d shell in the PC-reduced SeNPs we can see that SeNPs were partially formed, as evidenced by the low peak of Se 3d3 at 54.4 mV and the unreacted Na₂SeO₃ peak (Se²⁺ 3d3 at 58.3 eV, Figure S1). With the coating of _D-/_L-/_DL-GSH, the yield of elementary Se states was greatly increased, as evidenced by the increased intensity of Se 3d3 and Se 3d5 peaks from the _L-G@SeNPs, _D-G@SeNPs and _DL-G@SeNPs spectra. Also, a low peak from SeO appeared at 59.0 eV in the Se 3d shell spectrum from the _D-G@SeNPs but was completely absent from the _L- G@SeNPs and _DL-G@SeNPs spectra. This indicates that _L-GSH has a stronger reducing ability than _D-GSH and produces a higher yield of elementary Se. Additionally, the peaks of Se 3d_5/2 and Se 3d_3/2 from Se²⁻ were present in the _L-G@SeNPs spectrum (Figure 1g), and the presence of this state increases the reducing ability of the nanosystem. In the S 2p spectra from the _D-, _L-, _DL-G@SeNPs, the peaks at S 2p_3/2 and S 2p_1/2 were assumed to be generated by the Na₂SeO₃ and -SH from GSH or PC (Figure 1h). The structure of the chiral G@SeNPs was further characterized by FT-IR and UV-vis spectra (Figure S2a, b). Moreover, the chiral G@SeNPs showed excellent biocompatibility with red blood cells, as demonstrated by the low hemolysis rate in Figure S3.

Intravenously administered nanoparticles are cleared from the body through two main pathways: hepatobiliary elimination and renal elimination^[18]. To identify whether nanoparticles with different chirality exhibit distinct biodistributions, PET scans was conducted on radiolabeled nanoparticles. For radiolabeling, the chiral G@SeNPs were coupled with ⁶⁴Cu through the linkage of p-SCN-Bn-NOTA at pH 5.5 (Figure 2a, I). Thin-layer chromatography (TLC), a useful tool to assess the binding of radioactive nuclei in radiolabeled compounds, shows a high radioactivity and radiochemical purity of ⁶⁴Cu-_L-G@SeNPs, ⁶⁴Cu-_D-G@SeNPs and ⁶⁴Cu-DL-G@SeNPs in an aqueous phase (Figure 2a, II), with the radiolabeling efficiencies were 96.5%, 88.5% and 97.3%, respectively (Figure 2a, II). The stability of radiolabeled nanoparticles in serum is essential for in vivo applications. As shown in Figure S4, the stability of the ⁶⁴Cu-_L-G@SeNPs, ⁶⁴Cu-_D-G@SeNPs and ⁶⁴Cu-_DL-G@SeNPs in serum was demonstrated with 69.4 ± 16.0%, 69.1% ± 13.5% and 69.8% ± 3.2% respectively, of the radioactivity remaining bound after 24 h of incubation. Having successfully radiolabeled the nanoparticles with ⁶⁴Cu, PET imaging was performed after intravenous injection of ⁶⁴Cu-_L-G@SeNPs, ⁶⁴Cu-_D-G@SeNPs and ⁶⁴Cu-_DL-G@SeNPs into healthy mice. Both the images (Figure 2b) and the Region of Interest (ROI) data (Figures 2c-2f) revealed that ⁶⁴Cu-_L-G@SeNPs accumulated mainly in the liver and intestines after 4 h. For the liver, the concentration of ⁶⁴Cu-_L-G@SeNPs was the highest after injection and remained high throughout the observation period. By contrast, ⁶⁴Cu-_D-G@SeNPs and ⁶⁴Cu-_DL-G@SeNPs displayed minimal accumulation in the liver, with 2.0 ~ 2.9 fold lower %ID/g levels than ⁶⁴Cu-_L-G@SeNPs throughout the 24 h of observation. As for the other main organs in the hepatobiliary elimination pathway, the spleen and intestines also have higher uptakes of ⁶⁴Cu-_L-G@SeNPs than their _D- and _DL- counterparts 4 h after injection (Figure 2b, d, e). On the other hand, the ROI data for kidneys suggest that ⁶⁴Cu-_DL-G@SeNPs and ⁶⁴Cu-_D-G@SeNPs exerted faster renal clearance than _L-counterpart throughout the 24-h observation following injection (Figure 2f). Noteworthily, ⁶⁴Cu-_DL-G@SeNPs localized in kidney faster than the _D-counterpart, as shown by the stonger ⁶⁴Cu radioactivity in the kidney. It is possible that the neutral charge and steric conformation of _DL-G@SeNPs facilitate the electrostatic interaction with the negatively charged glomerular endothelium in kidney^[19], and reduce the opsonization to retard the sequestration by mononuclear phagocytic system (MPS)^[20]. Correspondingly, the ex vivo biodistribution data (Figure 2g) revealed a significant difference in uptake among the ⁶⁴Cu-_L-G@SeNPs, ⁶⁴Cu-_D-G@SeNPs and ⁶⁴Cu-_DL-G@SeNPs in the liver, spleen, pancreas, intestines and kidney at 24 h p.i. In addition, for the nanosystem of either _L-, _D- or _DL-G@SeNPs, the chiral GSH, PC and Se²⁻ (only existed in _L-G@SeNPs) reduced some ⁶⁴Cu(II) to ⁶⁴Cu(I)^[21], which disassociated some ⁶⁴Cu²⁺ from the nanoparticles, and were quickly transported to liver and eliminated through bladder^[22] by 4 h, as demosntrated by the PET imaging.

Figure 2. PET imaging of chiral G@SeNPs in vivo.

(a) I: Scheme of the preparation of ⁶⁴Cu-radiolabeled chiral G@SeNPs. II: The labeling yield of ⁶⁴Cu-_L-G@SeNPs, ⁶⁴Cu-_D-G@SeNPs and ⁶⁴Cu-_DL-G@SeNPs. (b) PET scans on mice after IV injection of ⁶⁴Cu-_L-G@SeNPs, ⁶⁴Cu-_D-G@SeNPs and ⁶⁴Cu-_DL-G@SeNPs. Tracer uptake (% ID/g) for ⁶⁴Cu-_L-G@SeNPs, ⁶⁴Cu-_D-G@SeNPs and ⁶⁴Cu-_DL-G@SeNPs treatment groups in liver (c), spleen (d), intestine (e) and kidney (f) based on the quantitative ROI analysis of PET images. (g) Biodistribution of ⁶⁴Cu-_L-G@SeNPs, ⁶⁴Cu-_D-G@SeNPs and ⁶⁴Cu-_DL-G@SeNPs in major organs at 24 h p.i. (h) Se concentration in liver, kidney and intestine after IV injection of ⁶⁴Cu-_L-G@SeNPs, ⁶⁴Cu-_D-G@SeNPs and ⁶⁴Cu-_DL-G@SeNPs at 24 h (n=3). Bars with different characters are statistically significant (P < 0.05 level, Tukey’s test, one-way ANOVA).

Since ⁶⁴Cu shares the same target organ (i.e., liver) with many kinds of nanoparticles, a second means is highly desirable to analyze the distribution of nanoparticle^[22]. Therefore, the Se content of _L-, _D- and _DL-G@SeNPs (Figure 2h) in main organs,including kidney, liver and intestine was measured in this study. The results showed a similar trend comparing with the ex-vivo biodistribution analysis, implying that SeNPs and ⁶⁴Cu in each chiral nanosystem have similar metabolism routes after the primary localization.

To further understand the transformation and elimation way of ⁶⁴Cu-labeled chiral G@SeNPs, the ⁶⁴Cu states and Se speciation in mice urine were analyzed by Radio-TLC and LC-ICP-MS respectively. As shown in Figure S5, the majority of urine collected at 4 h p.i, in _D- _L- and _DL-groups were filled with detached ⁶⁴Cu from the nanoparticles, and that collected at 12 and 24 h p.i appeared smaller amount of chelated ⁶⁴Cu. To examine the Se metabolism after renal clearance, the total Se and the main Se species in the urine were quantified by HPLC-ICP-MS. As shown in Figure S6, SeCys and selenite were detected in the groups after IV injection for different periods of time, suggesting that chiral SeNPs could be transformed to SeCys and selenite to execute the bioacitvity. Besides, the concentration of total Se was found much higher than those of the detected Se species (Figure S7), suggesting that some other undetected Se species may exist in the urine. Moreover, TEM images of urine in all groups clearly evidenced the presence of small nanoparticles with the size at approximately 70 nm (Figure S8). These results suggest that chiral SeNPs undergoing liver/renal clearance could possibly be degraded into smaller nanoparticles and other Se metabolites (including SeCys and selenite) or conjugates, and finally excreted into the urine.

Collectively, we have observed the distinctive biodistribution routes among _L-, _D- and _DL-G@SeNPs. The distribution of the _L-G@SeNPs in the liver, kidneys, and intestines were consistent with those commonly reported^[18]. However, the _D-G@SeNPs and _DL-G@SeNPs escaped from the hepatobiliary pathway and suffered a faster renal clearance than the naturally existing _L-G@SeNPs, which might be due to the lower cell adhesion of _D-GSH with biological components, i.e., plasma membranes, proteins and corona from different organs and blood constituents^{[1a, 23]}. Especially, the stronger renal localization of _DL-G@SeNPs than that of _D-counterpart was ascribed to its neutral charge and steric conformation, which facilitated the electrostatic interaction with kidney, and reduced the opsonization to retard the sequestration by MPS.

Because of their increased reducing capability, a higher uptake of _L-G@SeNPs in the major organs is assumed to have a stronger antioxidant effect over the _D-G@SeNPs. To explore this hypothesis, we investigated the protective effects of chiral G@SeNPs (_D-, _L- and _DL-form) against PA-caused oxidative damage in INS-1E β cells. First, the viability of chiral G@SeNPs against INS-1E cells was screened. As shown in Figure 3a, 0.4 μM PA decreased the viability of INS-1E cells to 73.9%. However, pretreatment with the chiral G@SeNPs with the Se concentration ranging from 0.2 to 1.6 μM effectively demonstrated an attenuation of the cytotoxicity caused by treatment with the PA alone. Comparing the results, we can see that the pretreatment of _L-G@SeNPs preserved the viability of INS-1E cells at a higher level than the _D-G@SeNPs or _DL-G@SeNPs. Consistent with this result, we found that _L-G@SeNPs effectively inhibited the PA-caused apoptosis in INS-1E cells, as evidenced by the decreased apoptotic proportion of Sub G1 cells than for the other groups in the stacked bars (Figure 3b). Furthermore, pretreatment with _L-G@SeNPs decreased the activity of caspase-8 and caspase-9 in PA-treated INS1-E cells than those of _D- and _DL-counterparts (Figure S9), demonstrating the stronger preventive effect of _L-G@SeNPs against PA-caused apoptosis.

Figure 3. Chiral G@SeNPs reduced PA-induced apoptosis in INS-1 cells.

(a) Viability of INS-1E cells after treatment with chiral G@SeNPs and PA detected by MTT assay. (b) Cell cycle of INS-1E cells after treatment with chiral G@SeNPs and PA detected by flow cytometry. (c) Intracellular ROS level in INS-1E cells after treatments of chiral G@SeNPs and PA, as detected by using DHE fluorescent probe. The data were presented as the means ± SD, n = 3. *, ** and *** indicated the statistical significance between each treatment group and control group at P< 0.05, 0.01 and 0.001 level respectively. (d) Absorbance spectra of ABTS^{• +} after exposure to chiral G@SeNPs and PA. (e) Mitochondrial fragmentation in INS-1E cells after treatments of chiral G@SeNPs and PA. The white arrows indicated the fragmented dots of mitochondria.

Intracellular reactive oxygen species (ROS), one of the critical stimuli to trigger apoptosis^[24], was measured in INS-1E cells after all treatments. As shown in Figure 3c, pretreatment with the _L-G@SeNPs outperformed _D-G@SeNPs and _DL-G@SeNPs by more effectively scavenging PA-caused ROS in INS-1E cells and showed no statistical differences with control group. To confirm the scavenging ability of the _L-G@SeNPs, an ABTS assay was conducted. As shown in Figure 3d, the _L-, _D- and _DL-G@SeNPs significantly decreased the absorbance of ABT^•+ at 734 nm, displaying approximately 1.7 and 1.5 folds stronger respectively. This result suggests that the combination of SeNPs, PC and GSH in one nanosystem creates a synergistic antioxidant effect on PA-caused ROS. Peculiarly, the scavenging ability of the different chiral G@SeNPs was not evident in vitro. This implies that the higher antioxidant ability of the _L-G@SeNPs observed in the INS-1E cells relied on the differential uptake of the G@SeNPs with homologous recognition by cell membrane and the subsequent signaling transduction in live cells.

Mitochondrial fragmentation, a major producer of ROS, occurs frequently in the process of PA-caused apoptosis^[25]. This motivated us to monitor the mitochondrial state in INS-1E cells after treatment with chiral G@SeNPs and PA sequentially. As shown in Figure 3e, the mitochondria in healthy INS-1E cells were randomly distributed throughout the cytoplasm, while after treatment with PA there was evident mitochondrial fragmentation, indicated by the white arrows in INS-1E cells image. However, pretreatment with the chiral G@SeNPs effectively prevented the PA-caused mitochondrial fragmentation, and specifically, _L-G@SeNPs demonstrated a stronger preventative effect than _D-G@SeNPs and _DL-G@SeNPs.

Next we set out to investigate whether the higher antioxidant activity of _L-G@SeNPs can be ascribed to homologous adhesion between the cell membrane and _L-GSH. The colocalization of the various chiral species on the INS-1E cell membrane was compared under a fluorescent microscope. The coumarin-6 was incorporated in the chiral G@SeNPs so that their spatial distribution could be observed. Figure 4a and Figure S10 revealed the greater adherence of the _L-G@SeNPs to the cell membrane than their _D-and _DL-counterparts after 24 h of incubation, as shown by the strong overlap of green and red fluorescence in the merged image. The 3D view images help to visualize the spatial colocalization of _L-G@SeNPs and the cell membrane after co-incubation for 6 h. The Pearson correlation coefficient (PCC), which measures the amount or degree of colocalization among different color channels^[26], was measured and analyzed for each group. Figure 4b showed that the PCC values for the _L-G@SeNPs group was higher than those of the _D-G@SeNPs and _DL-G@SeNPs groups after 3, 6 and 24 h of incubation. Notably, the histogram of the PCC values showed that at 6 h a drastically stronger colocalization of _L-G@SeNPs on the cell membrane has taken place compared to that of the _D-G@SeNPs or _DL-G@SeNPs (Figure 4b). This suggests stronger homologous adhesion of the _L-G@SeNPs to the INS-1E cells. We supposed that the stronger adhesion of _L-G@SeNPs contributed to higher cellular uptake efficacy. As predicted, the uptake efficacy of _L-G@SeNPs was significantly higher than that of _D-G@SeNPs and _DL-G@SeNPs throughout the 24 h observational period (Figure 4c). Collectively, our results indicated that INS-1E cells preferred to internalize the _L-G@SeNPs through the preferable interaction between the _L-phospholipid-based cell membrane and the natural type of _L-GSH, which comply to the natural selection patterns.

Figure 4. Localization and cellular uptake of chiral G@SeNPs in INS-1E cells.

(a) Representative fluorescent images of chiral G@SeNPs-treated INS-1E cells by 6 h. The 3D view of merged images was acquired by ImageJ software. INS-1E cell membrane was stained with Dir (Red), while the nucleus was stained with Hoechst (blue). (b) Pearson correlation coefficient of the fluorescent images of Figure 6A, as calculated by Image J Software. The data were presented as the means ± SD, n = 3. (c) Cellular uptake efficacy of chiral G@SeNPs in INS-1E cells for 24 h. The data were presented as the means ± SD, n = 3. Bars with different characters are statistically significant (P < 0.05 level, Tukey’s test, one-way ANOVA).

In summary, the influence of chirality on the biodistribution and oxidation prevention was elucidated for chiral G@SeNPs. With the coupling of _L- or _D-GSH on the surface, the chiral nanosystem was successfully prepared. The biodistribution of the chiral G@SeNPs was investigated by PET imaging with ⁶⁴Cu labeling. Our findings demonstrate that the chirality of nanosystem determines the primary localization of chiral G-SeNPs in either liver, intestine or kidney, and affects the distribution routes and speed of constituents in each nanosystem. _L-G@SeNPs exhibited preferential accumulation in the liver, spleen and pancreas, while their _DL- and _D-counterparts escaped from liver uptake and suffered faster renal clearance. Taking advantage of the homologous adhesion between _L-GSH and the _L-phospholipid membrane, _L-G@SeNPs increased affinity for the cell membrane and by extension higher concentration in the vicinity prevented PA-caused oxidative damage in INS-1 cells by attenuating ROS and mitochondrial fragmentation at a higher level than _D-G@SeNPs. Deeper mechanism studies are needed to explore on the relationship among the steric conformation of chiral G@SeNPs and their metabolism as well as long-term toxicity. Overall, our findings clearly demonstrate the chirality-dependent biodistribution and antioxidant activity of chiral G@SeNPs in β cells, illuminating the way for development of chiral nanomedicine and for translation from benchtop to bedside.