Fabrication of High-Density Microarchitected Tungsten via DLP 3D Printing.

Current additive manufacturing (AM) techniques for tungsten, such as powder bed fusion and directed energy deposition, often generate parts with rough surfaces. Vat photopolymerization presents a promising alternative for fabricating tungsten structures with high shape fidelity and low surface roughness. However, existing vat photopolymerization approaches suffer from surface defects and low final density, leading to compromised mechanical properties. Therefore, achieving high-density tungsten structures using vat photopolymerization remains a crucial challenge. This work presents a straightforward and reliable method for fabricating complex, micro-architected tungsten structures with superior density and hardness. The approach utilizes a water-based photoresin with exceptional tungsten ion loading capacity. The photoresin is then patterned using digital light processing (DLP) to create tungsten-laden precursors. A three-step debinding and sintering process subsequently achieves 3D tungsten structures with dense surface morphology and minimal internal defects. The microstructures achieve a minimum feature size of 35 µm, a low surface roughness of 2.86 µm, and demonstrate exceptional mechanical properties. This new method for structuring tungsten opens doors to a broad range of applications, including micromachining, collimators, detectors, and metamaterials.

Unveiling novel insights into human IL-6 - IL-6R interaction sites through 3D computer-guided docking and systematic site mutagenesis.

The cytokine interleukin-6 (IL-6) plays a crucial role in autoimmune and inflammatory diseases. Understanding the precise mechanism of IL-6 interaction at the amino acid level is essential to develop IL-6-inhibiting compounds. In this study, we employed computer-guided drug design tools to predict the key residues that are involved in the interaction between IL-6 and its receptor IL-6R. Subsequently, we generated IL-6 mutants and evaluated their binding affinity to IL-6R and the IL-6R - gp130 complex, as well as monitoring their biological activities. Our findings revealed that the R167A mutant exhibited increased affinity for IL-6R, leading to enhanced binding to IL-6R - gp130 complex and subsequently elevated intracellular phosphorylation of STAT3 in effector cells. On the other hand, although E171A reduced its affinity for IL-6R, it displayed stronger binding to the IL-6R - gp130 complex, thereby enhancing its biological activity. Furthermore, we identified the importance of R178 and R181 for the precise recognition of IL-6 by IL-6R. Mutants R181A/V failed to bind to IL-6R, while maintaining an affinity for the IL-6 - gp130 complex. Additionally, deletion of the D helix resulted in complete loss of IL-6 binding affinity for IL-6R. Overall, this study provides valuable insights into the binding mechanism of IL-6 and establishes a solid foundation for future design of novel IL-6 inhibitors.

Development of novel monoclonal antibodies for blocking NF-κB activation induced by CD2v protein in African swine fever virus.

Background: CD2v, a critical outer envelope glycoprotein of the African swine fever virus (ASFV), plays a central role in the hemadsorption phenomenon during ASFV infection and is recognized as an essential immunoprotective protein. Monoclonal antibodies (mAbs) targeting CD2v have demonstrated promise in both diagnosing and combating African swine fever (ASF). The objective of this study was to develop specific monoclonal antibodies against CD2v. Methods: In this investigation, Recombinant CD2v was expressed in eukaryotic cells, and murine mAbs were generated through meticulous screening and hybridoma cloning. Various techniques, including indirect enzyme-linked immunosorbent assay (ELISA), western blotting, immunofluorescence assay (IFA), and bio-layer interferometry (BLI), were employed to characterize the mAbs. Epitope mapping was conducted using truncation mutants and epitope peptide mapping. Results: An optimal antibody pair for a highly sensitive sandwich ELISA was identified, and the antigenic structures recognized by the mAbs were elucidated. Two linear epitopes highly conserved in ASFV genotype II strains, particularly in Chinese endemic strains, were identified, along with a unique glycosylated epitope. Three mAbs, 2B25, 3G25, and 8G1, effectively blocked CD2v-induced NF-κB activation. Conclusions: This study provides valuable insights into the antigenic structure of ASFV CD2v. The mAbs obtained in this study hold great potential for use in the development of ASF diagnostic strategies, and the identified epitopes may contribute to vaccine development against ASFV.

Enhancement of Skin Delivery of Drugs Using Proposome Depends on Drug Lipophilicity.

The study aims to investigate the propylene glycol-based liposomes named 'proposomes' in enhancing skin permeation of drugs with different physicochemical properties. Ibuprofen, tofacitinib citrate, rhodamine B, and lidocaine were loaded into proposomes. These drug formulations were analyzed for particle size, zeta potential, polydispersity index, entrapment efficiency, and in vitro skin permeation. The confocal laser scanning microscopy was performed on skin treated with calcein and rhodamine B laden proposomes. The transdermal delivery relative to physicochemical properties of drugs such as logP, melting point, molecular weight, solubility, etc., were analyzed. We tested the safety of the proposomes using reconstructed human skin tissue equivalents, which were fabricated in-house. We also used human cadaver skin samples as a control. The proposomes had an average diameter of 128 to 148 nm. The drug's entrapment efficiencies were in the range of 42.9-52.7%, translating into the significant enhancement of drug permeation through the skin. The enhancement ratio was 1.4 to 4.0, and linearly correlated to logP, molecular weight, and melting point. Confocal imaging also showed higher skin permeation of calcein and rhodamine B in proposome than in solution. The proposome was found safe for skin application. The enhancement of skin delivery of drugs through proposomes was dependent on the lipophilicity of the drug. The entrapment efficiency was positively correlated with logP of the drug, which led to high drug absorption.

Proposome for transdermal delivery of tofacitinib.

Tofacitinib citrate (TC) has recently gained interest in treating skin disorders such as psoriasis, atopic dermatitis and baldness. Unfortunately, the oral administration shows side effects, such as decreased neutrophil counts. To this end, the topical delivery of TC can be used to reduce the risk associated with systemic exposure. However, TC shows minimal absorption via skin. Hence, the objective of this study is to enhance the skin delivery of TC using a non-invasive approach. The liposomes based on propylene glycol, named as proposomes, carrying TC, were studied. The vesicle characteristics and in vitro skin permeation were assessed. The proposomes enhanced the skin permeability of TC by 4-11 folds. The composition of proposomes was found to affect the skin permeation and deposition of TC. The proposomes were stable for at least 6 months. Overall, proposomes were effective for targeted topical drug delivery.

Microneedles with Tunable Dissolution Rate.

Dissolvable microneedle (MN) patches have been widely investigated for transdermal drug delivery. The dissolution rate of MN controls the status of drug release from the MN, which in turn determines drug absorption through skin. However, no systematic approaches have been reported to tune the dissolution profile of dissolvable MN matrices. This is the first study to show polyvinylpyrrolidone (PVP)-based dissolvable MN patches with varying dissolution profiles when PVP is copolymerized with cellulose materials. The MN patches were fabricated through thermal curing and photolithography in tandem. The various grades of pharmaceutical cellulose, such as hydroxypropyl methylcellulose and methyl cellulose, have been investigated as dissolution modifier incorporated in the MN patches. The resultant MN patches had dissolution profiles ranging from 45 min to 48 h. The dissolution rates varied with the grades of cellulose materials. Besides dissolution examination, the MN patches were characterized for their mechanical strength, moisture absorption, and skin penetration efficiency. All of the MN patches were able to penetrate the human skin in vitro. Overall, the PVP MN patches have great potential for skin applications as drug carriers with tunable dissolution profiles.

Rapid microneedle fabrication by heating and photolithography.

Many fabrication methods for microneedle (MN) involve harsh conditions and long drying time. This study aims to fabricate a dissolving MN patch in a simple and efficient manner under mild conditions, using a combination of thermal and photo polymerisation. The MN patch was fabricated by pre-polymerisation of vinylpyrrolidone solution with heating followed by photolithography. The heating temperature and time of pre-polymer solution curing were optimized based on viscosity measurement. The MN properties including shape, size, skin penetration, dissolution, moisture absorption were determined. The fabricated MNs were sharp and consistent. The heated N-vinylpyrrolidone solution required less UV exposure time, thus reducing the total fabrication time. The percentage of MN penetration in human cadaver skin was more than 33.9%. The MN was dissolved within 1-2 min in water, or 40 min in saturated water vapor.

Improving Cancer Vaccine Efficiency by Nanomedicine.

Cancer vaccines, which have been widely investigated in the past few decades, are one of the most attractive strategies for cancer immunotherapy. Through the precise delivery of antigens and adjuvants to lymphoid organs or lymphocytes via nanotechnology, innate and adaptive immunity can be boosted to prevent the growth and relapse of malignant tumors. Indeed, nanomedicine offers great opportunities to improve the efficiency of vaccines. Various functional platforms are used to deliver small molecules, peptides, nucleic acids, and even whole cell antigens to the target area of interest, achieving enhanced antitumor immunity and durable therapeutic benefits. Herein, the recent progress in cancer vaccines based on nanotechnology is summarized. Novel platforms used for delivering tumor antigens, promoting adjuvant functions, and combining other therapeutic strategies are discussed. Moreover, possible striving directions and major challenges of nanomedicine for vaccination are also reviewed.