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Metasurfaces have recently emerged as a promising technology to realize flat optical components with customized functionalities. In particular, their application to lenses in various imaging systems is of significant interest. However, a systematic and complete study of the focusing and imaging behavior of metalenses has not yet been conducted. In this work we analyze not only the on-axis focusing performance, but also the field-dependent wavefront aberrations via a phase-retrieval optimization method. We find that, particularly for high-NA metalenses, the field-dependent geometrical aberrations like coma are dominant at the design wavelength, while for longer and shorter operation wavelengths, the effective numerical aperture is decreased and mainly spherical aberrations are dominant. Additionally, we investigate the spectral and angular bandwidth of a polarization-insensitive metalens by analyzing the metalens efficiencies as a function of numerical aperture, field angle, and wavelength. We then compare...

Emerging two-dimensional (2D) nanomaterials, such as transition-metal dichalcogenide (TMD) nanosheets (NSs), have shown tremendous potential for use in a wide variety of fields including cancer nanomedicine. The interaction of nanomaterials with biosystems is of critical importance for their safe and efficient application. However, a cellular-level understanding of the nano-bio interactions of these emerging 2D nanomaterials (i.e., intracellular mechanisms) remains elusive. Here we chose molybdenum disulfide (MoS2) NSs as representative 2D nanomaterials to gain a better understanding of their intracellular mechanisms of action in cancer cells, which play a significant role in both their fate and efficacy. MoS2 NSs were found to be internalized through three pathways: clathrin → early endosomes → lysosomes, caveolae → early endosomes → lysosomes, and macropinocytosis → late endosomes → lysosomes. We also observed autophagy-mediated accumulation in the lysosomes and exocytosis-induced efflux of MoS2 NSs. Ba...

The present work proposes a unique de-PEGylation strategy for controllable delivery of small interfering RNA (siRNA) using a robust lipid-polymer hybrid nanoparticle (NP) platform. The self-assembled hybrid NPs are composed of a lipid-poly(ethylene glycol) (lipid-PEG) shell and a polymer/cationic lipid solid core, wherein the lipid-PEG molecules can gradually dissociate from NP surface in the presence of serum albumin. The de-PEGylation kinetics of a series of different lipid-PEGs is measured with their respective NPs, and the NP performance is comprehensively investigated in vitro and in vivo. This systematic study reveals that the lipophilic tails of lipid-PEG dictate its dissociation rate from NP surface, determining the uptake by tumor cells and macrophages, pharmacokinetics, biodistribution, and gene silencing efficacy of these hybrid siRNA NPs. Based on our observations, we here propose that lipid-PEGs with long and saturated lipophilic tails might be required for effective siRNA delivery to tumor cells and gene silencing of the lipid-polymer hybrid NPs after systemic administration.

The effect of various inorganic and organic counterions on the aggregation behavior of gemini surfactants was examined to investigate the dominant influence of the anions on their micellization and aggregation behavior. This study included eight ethanediyl-α,ω-bis-(dimethylhexadecylammonium) gemini surfactants (GS, also known as 16–2–16) having counterions of chloride (Cl−), bromide (Br−), malate, tartrate, adenosine monophosphate (AMP), guanosine monophosphate (GMP), cytidine monophosphate (CMP), and uridine monophosphate (UMP). Tensiometry, conductivity and Langmuir monolayer measurements were performed to investigate the micellization and surface behaviour of each surfactant.

Spurred by recent progress in medicinal chemistry, numerous lead compounds have sprung up in the past few years, although the majority are hindered by hydrophobicity, which greatly challenges druggability. In an effort to assess the potential of platinum (Pt) candidates, the nanosizing approach to alter the pharmacology of hydrophobic Pt(IV) prodrugs in discovery and development settings is described. The construction of a self-assembled nanoparticle (NP) platform, composed of amphiphilic lipid-polyethylene glycol (PEG) for effective delivery of Pt(IV) prodrugs capable of resisting thiol-mediated detoxification through a glutathione (GSH)-exhausting effect, offers a promising route to synergistically improving safety and efficacy. After a systematic screening, the optimized NPs (referred to as P6 NPs) exhibited small particle size (99.3 nm), high Pt loading (11.24%), reliable dynamic stability (∼7 days), and rapid redox-triggered release (∼80% in 3 days). Subsequent experiments on cells support the emergence of P6 NPs as a highly effective means of transporting a lethal dose of cargo across cytomembranes through macropinocytosis. Upon reduction by cytoplasmic reductants, particularly GSH, P6 NPs under disintegration released sufficient active Pt(II) metabolites, which covalently bound to target DNA and induced significant apoptosis. The PEGylation endowed P6 NPs with in vivo longevity and tumor specificity, which were essential to successfully inhibiting the growth of cisplatin-sensitive and -resistant xenograft tumors, while effectively alleviating toxic side-effects associated with cisplatin. P6 NPs are, therefore, promising for overcoming the bottleneck in the development of Pt drugs for oncotherapy.

Emerging two-dimensional (2D) nanomaterials, such as transition-metal dichalcogenide (TMD) nanosheets (NSs), have shown tremendous potential for use in a wide variety of fields including cancer nanomedicine. The interaction of nanomaterials with biosystems is of critical importance for their safe and efficient application. However, a cellular-level understanding of the nano-bio interactions of these emerging 2D nanomaterials ( i. e., intracellular mechanisms) remains elusive. Here we chose molybdenum disulfide (MoS

Photothermal therapy (PTT) has shown significant potential for cancer therapy. However, developing nanomaterials (NMs)-based photothermal agents (PTAs) with satisfactory photothermal conversion efficacy (PTCE) and biocompatibility remains a key challenge. Herein, a new generation of PTAs based on two-dimensional (2D) antimonene quantum dots (AMQDs) was developed by a novel liquid exfoliation method. Surface modification of AMQDs with polyethylene glycol (PEG) significantly enhanced both biocompatibility and stability in physiological medium. The PEG-coated AMQDs showed a PTCE of 45.5%, which is higher than many other NMs-based PTAs such as graphene, Au, MoS2, and black phosphorus (BP). The AMQDs-based PTAs also exhibited a unique feature of NIR-induced rapid degradability. Through both in vitro and in vivo studies, the PEG-coated AMQDs demonstrated notable NIR-induced tumor ablation ability. This work is expected to expand the utility of 2D antimonene (AM) to biomedical applications through the development of an entirely novel PTA platform.

The present work proposes a unique de-PEGylation strategy for controllable delivery of small interfering RNA (siRNA) using a robust lipid-polymer hybrid nanoparticle (NP) platform. The self-assembled hybrid NPs are composed of a lipid-poly(ethylene glycol) (lipid-PEG) shell and a polymer/cationic lipid solid core, wherein the lipid-PEG molecules can gradually dissociate from NP surface in the presence of serum albumin. The de-PEGylation kinetics of a series of different lipid-PEGs is measured with their respective NPs, and the NP performance is comprehensively investigated in vitro and in vivo. This systematic study reveals that the lipophilic tails of lipid-PEG dictate its dissociation rate from NP surface, determining the uptake by tumor cells and macrophages, pharmacokinetics, biodistribution, and gene silencing efficacy of these hybrid siRNA NPs. Based on our observations, we here propose that lipid-PEGs with long and saturated lipophilic tails might be required for effective siRNA delivery to tumor cells and gene silencing of the lipid-polymer hybrid NPs after systemic administration.