Direct Selective Epitaxy of 2D Sb2Te3 onto Monolayer WS2 for Vertical p-n Heterojunction Photodetectors.

Two-dimensional transition metal dichalcogenides (2D-TMDs) possess appropriate bandgaps and interact via van der Waals (vdW) forces between layers, effectively overcoming lattice compatibility challenges inherent in traditional heterojunctions. This property facilitates the creation of heterojunctions with customizable bandgap alignments. However, the prevailing method for creating heterojunctions with 2D-TMDs relies on the low-efficiency technique of mechanical exfoliation. Sb2Te3, recognized as a notable p-type semiconductor, emerges as a versatile component for constructing diverse vertical p-n heterostructures with 2D-TMDs. This study presents the successful large-scale deposition of 2D Sb2Te3 onto inert mica substrates, providing valuable insights into the integration of Sb2Te3 with 2D-TMDs to form heterostructures. Building upon this initial advancement, a precise epitaxial growth method for Sb2Te3 on pre-existing WS2 surfaces on SiO2/Si substrates is achieved through a two-step chemical vapor deposition process, resulting in the formation of Sb2Te3/WS2 heterojunctions. Finally, the development of 2D Sb2Te3/WS2 optoelectronic devices is accomplished, showing rapid response times, with a rise/decay time of 305 µs/503 µs, respectively.

Eyedrop delivery of therapeutic proteins with zwitterionic polymers to treat dry age-related macular degeneration.

In clinics, therapeutic proteins are commonly used to treat retinal diseases through intraocular injection, the treatment which suffers from rather low patient compliance. Topical administration (e.g. eye-drops) of large molecule drugs remains a major challenge due to the presence of various barriers in the eye. In this study, zwitterion-grafted chitosan (CS-ZW) was developed and then self-assembled with protein therapeutics including adalimumab (ADA) or catalase (CAT) for the treatment of dry age-related macular degeneration (dAMD) via topical eyedrops. Since CS-ZW can cross the mucus layer and open the tight junctions between epithelial cells, their delivered therapeutic proteins can be shuttled across the ocular barriers to reach the diseased site in the fundus. CS-ZW/ADA eyedrops delivering ADA to bind TNF-α in the fundus achieved a similar therapeutic effect to intravitreal ADA injection in a mouse dAMD model. In addition, the therapeutic effect was further improved by combining eyedrop formulations of CS-ZW/ADA and CS-ZW/CAT, the latter of which can clear reactive oxygen species (ROS) in the lesion to further assist dAMD treatment. Our work provides a simple and effective delivery vehicle that can non-invasively treat fundus diseases such as dAMD, showing potential advantages in reducing side effects associated with intraocular injection and improving patient compliance.

Application of organic nanocarriers for intraocular drug delivery. / ç”¨äºŽçœ¼å† è¯ç‰©é€’é€çš„æœ‰æœºçº³ç±³è½½ä½“ç ”ç©¶.

The application of intraocular drug delivery is usually limited due to special anatomical and physiological barriers, and the elimination mechanisms in the eye. Organic nano-drug delivery carriers exhibit excellent adhesion, permeability, targeted modification and controlled release abilities to overcome the obstacles and improve the efficiency of drug delivery and bioavailability. Solid lipid nanoparticles can entrap the active components in the lipid structure to improve the stability of drugs and reduce the production cost. Liposomes can transport hydrophobic or hydrophilic molecules, including small molecules, proteins and nucleic acids. Compared with linear macromolecules, dendrimers have a regular structure and well-defined molecular mass and size, which can precisely control the molecular shape and functional groups. Degradable polymer materials endow nano-delivery systems a variety of size, potential, morphology and other characteristics, which enable controlled release of drugs and are easy to modify with a variety of ligands and functional molecules. Organic biomimetic nanocarriers are highly optimized through evolution of natural particles, showing better biocompatibility and lower toxicity. In this article, we summarize the advantages of organic nanocarriers in overcoming multiple barriers and improving the bioavailability of drugs, and highlight the latest research progresses on the application of organic nanocarriers for treatment of ocular diseases.

Highly Stable and Long-Circulating Metal-Organic Frameworks Nanoprobes for Sensitive Tumor Detection In Vivo.

High stability and extended circulation time in vivo are quite favorable for practical biomedical applications of nanomaterials, because they greatly facilitate the preferential tumor accumulation of nanomaterials, resulting in enhanced signal fidelity for imaging and improved therapeutic effect for treatment. Although many surface modification approaches have been employed to improve the stability and circulating behavior of nanomaterials, it still remains challenging in acquiring stable and long-lasting nanomaterials for in vivo bioimaging and therapy, especially for nanoscale metal-organic frameworks (NMOFs) due to their intrinsic instability in physiological conditions. Herein, a facile, one-step strategy is reported to encapsulate the zirconium (Zr)-based NMOF UiO-66 within 1,2-dioleoyl-sn-glycero-3-phosphate (DOPA) lipid bilayer (DOPA-LB). Contrary to UiO-66 NMOFs functionalized with polyethylene glycol, the obtained UiO-66@DOPA-LB presents significantly enhanced stability and impressive blood circulation time, allowing a higher accumulation of UiO-66@DOPA-LB in the tumor tissue. Benefited from these meritorious features, UiO-66@DOPA-LB labeled with near-infrared dye, IRDye 800CW, can not only achieve highly sensitive imaging of breast cancer tumor (5 mm), but also exhibits superior capability for early tumor (1-2 mm) detection. This study enriches the surface modification approach of NMOFs, and is of great importance for practical application of NMOFs in biomedical areas.