Publications by authors named "Lingxiao Xie"

Uveal melanoma (UM) is the most common primary intraocular tumor in adults with high mortality. In order to improve prognosis and survival of UM patients, it is critical to inhibit tumor progression and metastasis as early as possible after the initial presentation/diagnosis of the disease. Sustained local delivery of antitumor therapeutics in the posterior region can potentially achieve long-term UM inhibition, improve target therapeutic delivery to the posterior segments, as well as reduce injection frequency and hence improved patient compliance.

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Extruded 3D printing is emerging as an attractive fabrication technology in the field of personalized oral medicines. The objective of this study was to develop a tunable extruded 3D printing platform based on thermo-sensitive gelatin pastes to meet the needs of achieving different drug release characteristics with flexible dosing and design. The printability and mechanisms of extrusion and deposition of the gelatin pastes were systematically studied.

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Uveal melanoma (UM) is rare yet the most common and malignant primary intraocular tumor in adults. Due to the lack of effective treatment, the mortality rate of UM has remained high over the past few decades. In the present study, hyaluronic acid (HA) coated chitosan (Chi)/siRNA ternary complexes have been developed and characterized as a novel therapeutic strategy molecularly targeting hypoxia-inducible factor 1α (HIF-1α) pathway for the treatment of UM.

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Synthetic vector-based gene delivery continues to gain strength as viable alternatives to viral vectors due to safety and other concerns. DNA release dynamics is key to the understanding and control of gene delivery from nanosystems. Here we describe atomic force microscope (AFM) application to the understanding of DNA release dynamics from bioreducible polycation-based nanosystems.

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Layer-by-layer (LbL) films are assembled with poly(amido amine)s (PAAs), a type of polycations containing bioreducible disulfide bond, and DNA plasmids to enable LbL film degradation in physiologic conditions by reacting with glutathione or redox-active membrane proteins. The interior layer structure of the LbL films during assembly and disassembly is studied by atomic force microscopy (AFM), ellipsometry, dynamic light scattering (DLS), and fluorescence spectroscopy. Insertion of barrier layers in bioreducible LbL films is necessary to stabilize the interior layer structure and slow down the film degradation rate to achieve sequential gene delivery.

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Targeting the development of stimulus-responsive molecular materials with electronic functionality, we have synthesized and studied the redox and electronic properties of a new bimetallic iron hydrophobe [FeIII2(LN4O6)] (1). The new H6LN4O6 ligand displays bicompartmental topology capable of accomodating two five-coordinate HSFeIII ions bridged by tetraaminobenzene at a close distance of ca. 8 Å.

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Background: The layer-by-layer (LbL) assembly method offers a molecular level control of the amount and spatial distribution of bioactive molecules. However, successful clinical translation of LbL film technology will most certainly require a better understanding and control of not only the film assembly process, but also film disassembly kinetics in physiologic conditions.

Purpose: This work focuses on the understanding and control of degradation properties of LbL films for localized gene delivery.

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In this paper, we propose and demonstrate a novel approach to enhance the refractive index (RI) sensitivity and eliminate the temperature cross-sensitivity of a long-period grating (LPG) -based refractive index sensor by bent-fiber interference. The approach is based on a hybrid structure composed of an LPG and a bent-fiber intermodal interferometer. The bent-fiber intermodal interferometer has a simple structure, which consists of a bare fiber semi-circular bending region with a 5 mm bending radius.

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The current study was aimed to develop a targeted dendrimer formulation of 3, 4-difluorobenzylidene curcumin (CDF) and evaluate its potential in CD44 targeted therapy for pancreatic cancer. Using amine terminated fourth generation poly(amidoamine) (PAMAM) dendrimer nanocarrier and hyaluronic acid (HA) as a targeting ligand, we engineered a CD44-targeted PAMAM dendrimer (HA-PAMAM) formulation of CDF. The resulting dendrimer nanosystem (HA-PAMAM-CDF) had a particle size and surface charge of 9.

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Layer-by-layer (LbL) films containing cationic polyelectrolytes and anionic bioactive molecules such as DNA are promising biomaterials for controlled and localized gene delivery for a number of biomedical applications including cancer DNA vaccine delivery. Bioreducible LbL films made of disulfide-containing poly(amido amine)s (PAAs) and plasmid DNA can be degraded by redox-active membrane proteins through the thiol-disulfide exchange reaction to release DNA exclusively into the extracellular microenvironment adjacent to the film. In order to better understand the film degradation mechanism and nature of the released species, the bioreducible film degradation is studied by atomic force microscopy, fluorescence, and dynamic light scattering in solutions containing a reducing agent.

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In this paper, we present a free-standing metallodielectric grating structure that can achieve multiple transmission dips and peaks at normal incidence over the visible spectrum. The amount of dips and peaks can be adjusted by the thickness of dielectric film. In our proposed structure, there are three types of resonance modes supported: Surface plasmon polarition (SPP) at horizontal metal/dielectric interface, vertical cavity mode in the metal slits, and guide mode in the dielectric film.

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