The chirality of nanoparticles (NPs) and their assemblies has been investigated predominantly for noble metals and II-VI semiconductors. However, ceramic NPs represent the majority of nanoscale materials in nature. The robustness and other innate properties of ceramics offer technological opportunities in catalysis, biomedical sciences, and optics. Here we report the preparation of chiral ceramic NPs, as represented by tungsten oxide hydrate, WO·HO, dispersed in ethanol. The chirality of the metal oxide core, with an average size of ca. 1.6 nm, is imparted by proline (Pro) and aspartic acid (Asp) ligands via bio-to-nano chirality transfer. The amino acids are attached to the NP surface through C-O-W linkages formed from dissociated carboxyl groups and through amino groups weakly coordinated to the NP surface. Surprisingly, the dominant circular dichroism bands for NPs coated by Pro and Asp are different despite the similarity in the geometry of the NPs; they are positioned at 400-700 nm and 500-1100 nm for Pro- and Asp-modified NPs, respectively. The differences in the spectral positions of the main chiroptical band for the two types of NPs are associated with the molecular binding of the two amino acids to the NP surface; Asp has one additional C-O-W linkage compared to Pro, resulting in stronger distortion of the inorganic crystal lattice and greater intensity of CD bands associated with the chirality of the inorganic core. The chirality of WO·HO atomic structure is confirmed by atomistic molecular dynamics simulations. The proximity of the amino acids to the mineral surface is associated with the catalytic abilities of WO·HO NPs. We found that NPs facilitate formation of peptide bonds, leading to Asp-Asp and Asp-Pro dipeptides. The chiroptical activity, chemical reactivity, and biocompatibility of tungsten oxide create a unique combination of properties relevant to chiral optics, chemical technologies, and biomedicine.
Layer-by-Layer (LbL) self-assembly of nanocarriers has garnered the interest of researchers for a wide variety of biomedical applications. In this study, we demonstrated the preparation of poly(lactide-coglycolide) (PLGA)-(poly-L-ornithine (PLO)/fucoidan) 4 core-shell nanoparticles (LbL NPs) by a LbL-based self-assembly process, which possessed a mean size of 170 nm. In LbL NPs, a drug carrying PLGA nanocore is coated with alternating PLO and sulfated polysaccharide fucoidan composite films as a shell on the surface. The anti-tumor drug doxorubicin (DOX) loaded into the PLGA core, resulted in better encapsulation efficiency and its in vitro release from LbL NPs demonstrates that this core-shell strategy takes an advantage of its ability to hold the drug cargo and exhibit controlled release. Further, in vitro cell uptake studies by confocal laser scanning microscopy (CLSM) examination in breast tumor cells (MCF-7 cell line) have confirmed that the nanocarriers are successfully internalized and outlined their presence in the cytoplasm after 4 h of incubation. These intracellularly delivered DOX-loaded LbL NPs exhibited significant anti-tumor activity against breast tumor cells. This innovative chemotherapeutic design taking above advantages of successful internalization along with controlled release property signifies as a promising interventional therapeutic delivery system.
The in vitro and in vivo anti-tumor efficacy of methotrexate-loaded Fe 3 O 4 -poly-L-lactide-poly(ethylene glycol)-poly-L-lactide magnetic composite microspheres (MTX-Fe 3 O 4 -PLLA-PEG-PLLA MCMs, MMCMs), which were produced by co-precipitation (C) and microencapsulation (M) in a supercritical process, was evaluated at various levels: cellular, molecular, and integrated. The results at the cellular level indicate that MMCMs (M) show a better anti-proliferation activity than raw MTX and could induce morphological changes of cells undergoing apoptosis. At the molecular level, MMCMs (M) lead to a significantly higher relative mRNA expression of bax/bcl-2 and caspase-3 than MMCMs (C) at 10 µg mL 1 (P<0.01); and the pro-caspase-3 protein expression measured by Western blot analysis also demonstrates that MMCMs (M) can effectively activate pro-caspase-3. At the integrated level, mice bearing a sarcoma-180 tumor are used; in vivo anti-tumor activity tests reveal that MMCMs (M) with magnetic induction display a much higher tumor suppression rate and lower toxicity than raw MTX. Pharmacokinetic studies show that MMCMs (M) with magnetic induction significantly increase the accumulation of MTX in the tumor tissue compared with the other treatments. These results suggest that the MMCMs (M) prepared by the SpEDS process have great potential to play a positive role in the magnetic targeted therapy field.
A novel poly‐L‐arginine group microcapsule was produced to investigate its nutritional function and pharmacological efficacy. The molecular weight of poly‐L‐arginine is an important parameter for its membrane strength, but does not obviously affect its release property. Thus, poly‐L‐arginine can be used as a kind of new membrane material in microcapsules, and it is expected to be used as an therapeutic and biodegradable drug carrier.Influence of the molecular weight of poly‐L‐arginine on membrane thickness.magnified imageInfluence of the molecular weight of poly‐L‐arginine on membrane thickness.
Diabetes mellitus is the most common endocrine disease worldwide; hyperglycemia is a hallmark of this disease. To alleviate the pain caused by diabetes, developing and utilizing effective diabetic drugs to maintain or recover the function of the residual β-cells is an attractive therapeutic approach. γ-aminobutyric acid (GABA) has been shown to have such effects, but it is easy to have reduced GABA activity under physiological conditions. In the present study, GABA–chitosan nanoparticles (GABA–CS NPs) were prepared, and glucose homeostasis, pancreatic β-cell protection, and anti-inflammatory effects of GABA–CS NPs were investigated in vivo. The results showed that blood glucose levels and IL-1β levels in the GABA–CS NP-administered group were both significantly lower, whereas the PDX1 expression was significantly higher than that of the impaired group (p < 0.01). This indicates that GABA–CS NPs can efficiently maintain glucose homeostasis, protect β-cells, and inhibit inflammation. These nanoparticles have the potential to be applied for future diabetes theranostics.
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