Encapsulation of Amoxicillin within Laponite-Doped Poly(lactic-<i>co</i>-glycolic acid) Nanofibers: Preparation, Characterization, and Antibacterial Activity

We report a facile approach to encapsulating amoxicillin (AMX) within laponite (LAP)-doped poly­(lactic-co-glycolic acid) (PLGA) nanofibers for biomedical applications. In this study, a synthetic clay material, LAP nanodisks, was first used to encapsulate AMX. Then, the AMX-loaded LAP nanodisks with an optimized AMX loading efficiency of 9.76 ± 0.57% were incorporated within PLGA nanofibers through electrospinning to form hybrid PLGA/LAP/AMX nanofibers. The loading of AMX within LAP nanodisks and the loading of LAP/AMX within PLGA nanofibers were characterized via different techniques. In vitro drug release profile, antimicrobial activity, and cytocompatibility of the formed hybrid PLGA/LAP/AMX nanofibers were also investigated. We show that the loading of AMX within LAP nanodisks does not lead to the change of LAP morphology and crystalline structure and the incorporation of LAP/AMX nanodisks does not significantly change the morphology of the PLGA nanofibers. Importantly, the loading of AMX within LAP-doped PLGA nanofibers enables a sustained release of AMX, much slower than that within a single carrier of LAP nanodisks or PLGA nanofibers. Further antimicrobial activity and cytocompatibility assays demonstrate that the antimicrobial activity of AMX toward the growth inhibition of a model bacterium of Staphylococcus aureus is not compromised after being loaded into the hybrid nanofibers, and the PLGA/LAP/AMX nanofibers display good cytocompatibility, similar to pure PLGA nanofibers. With the sustained release profile and the reserved drug activity, the organic/inorganic hybrid nanofiber-based drug delivery system may find various applications in tissue engineering and pharmaceutical science

Highly Stable Luminous “Snakes” from CsPbX₃ Perovskite Nanocrystals Anchored on Amine-Coated Silica Nanowires

CsPbX3 (X = Cl, Br, and I) perovskite nanocrystals (NCs) are known for their exceptional optoelectronic properties, yet the material’s instability toward polar solvents, heat, or UV irradiation greatly limits its further applications. Herein, an efficient in situ growing strategy has been developed to give highly stable perovskite NC composites (abbreviated CsPbX3@CA-SiO2) by anchoring CsPbX3 NCs onto silica nanowires (NWs), which effectively depresses the optical degradation of their photoluminescence (PL) and enhances stability. The preparation of surface-functionalized serpentine silica NWs is realized by a sol–gel process involving hydrolysis of a mixture of tetraethyl orthosilicate (TEOS), 3-aminopropyl­triethoxysilane (APTES), and trimethoxy­(octadecyl)­silane (TMODS) in a water/oil emulsion. The serpentine NWs are formed via an anisotropic growth with lengths up to 8 μm. The free amino groups are employed as surface ligands for growing perovskite NCs, yielding distributed monodisperse NCs (∼8 nm) around the NW matrix. The emission wavelength is tunable by simple variation of the halide compositions (CsPbX3, X = Cl, Br, or I), and the composites demonstrate a high photoluminescence quantum yield (PLQY 32–69%). Additionally, we have demonstrated the composites CsPbX3@CA-SiO2 can be self-woven to form a porous 3D hierarchical NWs membrane, giving rise to a superhydrophobic surface with hierarchical micro/nano structural features. The resulting composites exhibit high stability toward water, heat, and UV irradiation. This work elucidates an effective strategy to incorporate perovskite nanocrystals onto functional matrices as multifunctional stable light sources

Cells Cultured on Core–Shell Photonic Crystal Barcodes for Drug Screening

The development of effective drug screening platforms is an important task for biomedical engineering. Here, a novel methacrylated gelatin (GelMA) hydrogel-encapsulated core–shell photonic crystal (PhC) barcode particle was developed for three-dimensional cell aggregation culture and drug screening. The GelMA shells of the barcode particles enable creation of a three-dimensional extracellular matrix (ECM) microenvironment for cell adhesion and growth, while the PhC cores of the barcode particles provide stable diffraction peaks that can encode different cell spheroids during culture and distinguish their biological response during drug testing. The applicability of this cell spheroids-on-barcodes platform was investigated by testing the cytotoxic effect of tegafur (TF), a prodrug of 5-fluorouracil (5-FU), on barcode particle-loaded liver HepG2 and HCT-116 colonic tumor cell spheroids. The cytotoxicity of TF against the HCT-116 tumor cell spheroids was enhanced in systems using cocultures of HepG2 and NIH-3T3 cells, indicating the effectiveness of this multiple cell spheroids-on-barcodes platform for drug screening