Inverse Lithography Physics-informed Deep Neural Level Set for Mask Optimization

As the feature size of integrated circuits continues to decrease, optical proximity correction (OPC) has emerged as a crucial resolution enhancement technology for ensuring high printability in the lithography process. Recently, level set-based inverse lithography technology (ILT) has drawn considerable attention as a promising OPC solution, showcasing its powerful pattern fidelity, especially in advanced process. However, massive computational time consumption of ILT limits its applicability to mainly correcting partial layers and hotspot regions. Deep learning (DL) methods have shown great potential in accelerating ILT. However, lack of domain knowledge of inverse lithography limits the ability of DL-based algorithms in process window (PW) enhancement and etc. In this paper, we propose an inverse lithography physics-informed deep neural level set (ILDLS) approach for mask optimization. This approach utilizes level set based-ILT as a layer within the DL framework and iteratively conducts mask prediction and correction to significantly enhance printability and PW in comparison with results from pure DL and ILT. With this approach, computation time is reduced by a few orders of magnitude versus ILT. By gearing up DL with knowledge of inverse lithography physics, ILDLS provides a new and efficient mask optimization solution

Graphene Oxide Wrapping on Squaraine-Loaded Mesoporous Silica Nanoparticles for Bioimaging

Squaraine dyes were loaded inside mesoporous silica nanoparticles, and the nanoparticle surfaces were then wrapped with ultrathin graphene oxide sheets, leading to the formation of a novel hybrid material. The hybrid exhibits remarkable stability and can efficiently protect the loaded dye from nucleophilic attack. The biocompatible hybrid is noncytotoxic and presents significant potential for application in fluorescence imaging in vitro

Spacer Intercalated Disassembly and Photodynamic Activity of Zinc Phthalocyanine Inside Nanochannels of Mesoporous Silica Nanoparticles

Hydrophobic photosensitizer zinc­(II) phthalocyanine (ZnPc) was loaded into adamantane (Ad) modified nanochannels of mesoporous silica nanoparticles (MSNPs). The Ad units on the surface of MSNPs were complexed with amino-substituted β-cyclodextrin to enhance the solubility of the hybrid in aqueous solution. The amino groups on β-cyclodextrin also provide functional sites for further conjugation with targeting ligands toward targeted cancer therapy. Since the intercalation of the Ad spacer isolates loaded ZnPc and prevents its aggregation inside MSNPs, ZnPc exhibits its monomeric characteristics to effectively generate cytotoxic singlet oxygen (¹O₂) upon light irradiation (675 nm) in aqueous conditions, leading to efficient photodynamic activity for successful cancer treatment in vitro. Current research presents a convenient approach to maintain the monomeric state of hydrophobic photosensitizer ZnPc by rationally utilizing multifunctional MSNPs as the carriers. The novel hybrid with targeting capability achieves active photodynamic property of monomeric ZnPc in aqueous solution under light irradiation, which may find its way for practical photodynamic therapy in the future

Catalytic Mesoporous Janus Nanomotors for Active Cargo Delivery

We report on the synergy between catalytic propulsion and mesoporous silica nanoparticles (MSNPs) for the design of Janus nanomotors as active cargo delivery systems with sizes <100 nm (40, 65, and 90 nm). The Janus asymmetry of the nanomotors is given by electron beam (e-beam) deposition of a very thin platinum (2 nm) layer on MSNPs. The chemically powered Janus nanomotors present active diffusion at low H₂O₂ fuel concentration (i.e., <3 wt %). Their apparent diffusion coefficient is enhanced up to 100% compared to their Brownian motion. Due to their mesoporous architecture and small dimensions, they can load cargo molecules in large quantity and serve as active nanocarriers for directed cargo delivery on a chip

Targeted Delivery of 5‑Aminolevulinic Acid by Multifunctional Hollow Mesoporous Silica Nanoparticles for Photodynamic Skin Cancer Therapy

5-Aminolevulinic acid (5-ALA) is a precursor of a strong photosensitizer, protoporphyrin IX (PphIX), for photodynamic therapy (PDT). Developing appropriate delivery carriers that can assist 5-ALA in bypassing the lipophilic barrier to directly enter into cancer cells is a research focus. The improved delivery of 5-ALA is even important for skin cancer therapy through PDT process. In this work, targeting ligand folic acid (FA)-functionalized hollow mesoporous silica nanoparticles (HMSNPs) were fabricated to deliver 5-ALA for PDT against B16F10 skin cancer cells. The FA targeting ligand enabled selective endocytosis of 5-ALA loaded HMSNPs into cancer cells. PphIX formed from delivered 5-ALA exhibited high photocytotoxicity to the cancer cells in vitro

Anticancer Effect of α‑Tocopheryl Succinate Delivered by Mitochondria-Targeted Mesoporous Silica Nanoparticles

Mitochondria targeted mesoporous silica nanoparticles (MSNPs) having an average diameter of 68 nm were fabricated and then loaded with hydrophobic anticancer agent α-tocopheryl succinate (α-TOS). The property of targeting mitochondria was achieved by the surface functionalization of triphenylphosphonium (TPP) on MSNPs, since TPP is an effective mitochondria-targeting ligand. Intracellular uptake and mitochondria targeting of fabricated MSNPs were evaluated in HeLa and HepG2 cancerous cell lines as well as HEK293 normal cell line. In addition, various biological assays were conducted with the aim to investigate the effectiveness of α-TOS delivered by the functional MSNPs, including studies of cytotoxicity, mitochondria membrane potential, intracellular adenosine triphosphate (ATP) production, and apoptosis. On the basis of these experiments, high anticancer efficiency of α-TOS delivered by mitochondria targeted MSNPs was demonstrated, indicating a promising application potential of MSNP-based platform in mitochondria targeted delivery of anticancer agents

Motion Control of Urea-Powered Biocompatible Hollow Microcapsules

The quest for biocompatible microswimmers powered by compatible fuel and with full motion control over their self-propulsion is a long-standing challenge in the field of active matter and microrobotics. Here, we present an active hybrid microcapsule motor based on Janus hollow mesoporous silica microparticles powered by the biocatalytic decomposition of urea at physiological concentrations. The directional self-propelled motion lasts longer than 10 min with an average velocity of up to 5 body lengths per second. Additionally, we control the velocity of the micromotor by chemically inhibiting and reactivating the enzymatic activity of urease. The incorporation of magnetic material within the Janus structure provides remote magnetic control on the movement direction. Furthermore, the mesoporous/hollow structure can load both small molecules and larger particles up to hundreds of nanometers, making the hybrid micromotor an active and controllable drug delivery microsystem

Motion Control of Urea-Powered Biocompatible Hollow Microcapsules

The quest for biocompatible microswimmers powered by compatible fuel and with full motion control over their self-propulsion is a long-standing challenge in the field of active matter and microrobotics. Here, we present an active hybrid microcapsule motor based on Janus hollow mesoporous silica microparticles powered by the biocatalytic decomposition of urea at physiological concentrations. The directional self-propelled motion lasts longer than 10 min with an average velocity of up to 5 body lengths per second. Additionally, we control the velocity of the micromotor by chemically inhibiting and reactivating the enzymatic activity of urease. The incorporation of magnetic material within the Janus structure provides remote magnetic control on the movement direction. Furthermore, the mesoporous/hollow structure can load both small molecules and larger particles up to hundreds of nanometers, making the hybrid micromotor an active and controllable drug delivery microsystem

Bubble-Free Propulsion of Ultrasmall Tubular Nanojets Powered by Biocatalytic Reactions

The motion of self-propelled tubular micro- and nano­jets has so far been achieved by bubble propulsion, e.g., O₂ bubbles formed by catalytic decomposition of H₂O₂, which renders future bio­medical applications inviable. An alternative self-propulsion mechanism for tubular engines on the nano­meter scale is still missing. Here, we report the fabrication and characterization of bubble-free propelled tubular nano­jets (as small as 220 nm diameter), powered by an enzyme-triggered bio­catalytic reaction using urea as fuel. We studied the translational and rotational dynamics of the nano­jets as functions of the length and location of the enzymes. Introducing tracer nano­particles into the system, we demonstrated the presence of an internal flow that extends into the external fluid via the cavity opening, leading to the self-propulsion. One-dimensional nano­size, longitudinal self-propulsion, and bio­compatibility make the tubular nano­jets promising for future bio­medical applications

Bubble-Free Propulsion of Ultrasmall Tubular Nanojets Powered by Biocatalytic Reactions

The motion of self-propelled tubular micro- and nano­jets has so far been achieved by bubble propulsion, e.g., O2 bubbles formed by catalytic decomposition of H2O2, which renders future bio­medical applications inviable. An alternative self-propulsion mechanism for tubular engines on the nano­meter scale is still missing. Here, we report the fabrication and characterization of bubble-free propelled tubular nano­jets (as small as 220 nm diameter), powered by an enzyme-triggered bio­catalytic reaction using urea as fuel. We studied the translational and rotational dynamics of the nano­jets as functions of the length and location of the enzymes. Introducing tracer nano­particles into the system, we demonstrated the presence of an internal flow that extends into the external fluid via the cavity opening, leading to the self-propulsion. One-dimensional nano­size, longitudinal self-propulsion, and bio­compatibility make the tubular nano­jets promising for future bio­medical applications