Nanoparticle clusters with molecular-like configurations are an emerging class of colloidal materials. Particles decorated with attractive surface patches acting as analogs of functional groups are used to assemble colloidal molecules (CMs); however, high-yield generation of patchy nanoparticles remains a challenge. We show that for nanoparticles capped with complementary reactive polymers, a stoichiometric reaction leads to reorganization of the uniform ligand shell and self-limiting nanoparticle bonding, whereas electrostatic repulsion between colloidal bonds governs CM symmetry. This mechanism enables high-yield CM generation and their programmable organization in hierarchical nanostructures. Our work bridges the gap between covalent bonding taking place at an atomic level and colloidal bonding occurring at the length scale two orders of magnitude larger and broadens the methods for nanomaterial fabrication.

Current interest in functional assemblies of inorganic nanoparticles (NPs) stems from their collective properties and diverse applications ranging from nanomedicines to optically active metamaterials. Coating the surface of NPs with polymers allows for tailoring of the interactions between NPs to assemble them into hybrid nanocomposites with targeted architectures. This class of building blocks is termed "hairy" inorganic NPs (HINPs). Regiospecific attachment of polymers has been used to achieve directional interactions for HINP assembly. However, to date anisotropic surface functionalization of NPs still remains a challenge. This Account provides a review of the recent progress in the self-assembly of isotropically functionalized HINPs in both the condensed state and aqueous solution as well as the applications of assembled structures in such areas as biomedical imaging and therapy. It aims to provide fundamental mechanistic insights into the correlation between structural characteristics and self-assembly behaviors of HINPs, with an emphasis on HINPs made from NPs grafted with linear block copolymer (BCP) brushes. The key to the anisotropic self-assembly of these HINPs is the generation of directional interactions between HINPs by designing the surrounding medium (e.g., polymer matrix) or engineering the surface chemistry of the HINPs. First, HINPs can self-assemble into a variety of 1D, 2D, or 3D nanostructures with a nonisotropic local arrangement of NPs in films. Although a template is not always required, a polymer matrix (BCPs or supramolecules) can be used to assist the assembly of HINPs to form hybrid architectures. The interactions between brushes of neighboring HINPs or between HINPs and the polymer matrix can be modulated by varying the grafting density and length of one or multiple types of polymers on the surface of the NPs. Second, the rational design of deformable brushes of BCP or mixed homopolymer tethers on HINPs enables the anisotropic assembly of HINPs (in analogy to molecular self-assembly) into complex functional structures in selective solvents. It is evidenced that the directional interactions between BCP-grafted NPs arise from the redistribution and conformation change of the long, flexible polymer tethers, while the lateral phase separation of brushes on NP surfaces is responsible for the assembly of HINPs carrying binary immiscible homopolymers. For HINPs decorated with amphiphilic BCP brushes, their self-assembly can produce a variety of hybrid structures, such as vesicles with a monolayer of densely packed NPs in the membranes and with controlled sizes, shapes (e.g., spherical, hemispherical, disklike), and morphologies (e.g., patchy, Janus-like). This strategy allows fine-tuning of the NP organization and collective properties of HINP assemblies, thus facilitating their application in effective cancer imaging, therapy, and drug delivery. We expect that the design and assembly of such HINPs with isotropic functionalization is likely to open up new avenues for the fabrication of new f...

Summary Objectives Intestinal tuberculosis (ITB) remains prevalent and a big health hazard in China. The aim of this study was to retrospectively analyse its clinico‐pathological features. Methods Retrospective study of 85 consecutive ITB patients in two tertiary hospitals in East China. Relevant clinical, laboratory examination, radiological, endoscopic and histopathological features of ITB were recorded. Results The mean age was 37.3 ± 16.0 years; 56 patients (65.9%) were male. 67.1% had ITB secondary to pulmonary tuberculosis. The overall median length of hospital stay was 28 days and was significantly longer in patients with intestinal complications (P = 0.003) and malnutrition (P = 0.042). Abdominal pain (88.2%) and weight loss (75.3%) were the commonest symptoms. The positive rate of the purified protein derivative (PPD) test was 88.2%; of the T‐spot, 85.7%. Histopathology revealed caseating granuloma in 70.6% and caseating necrosis in 24.7% of patients. The most commonly affected sites were the ileocecal valve (56, 65.9%), terminal ileum (40, 47.1%) and caecum (33, 38.8%). Only 17 (20%) patients were initially diagnosed as ITB, the other 68 patients were misdiagnosed. Six patients with caecum tuberculosis were misdiagnosed as appendicitis, four of whom had improper surgical procedures followed by post‐operative intestinal fistulas; two died due to MODS. Conclusions Diagnosis of ITB is often misdirected and delayed, which may lead to inappropriate treatment and high mortality. High diagnostic suspicion is necessary for patients with unexplained abdominal complaints. Diagnosis is not easy but could benefit coexisting pulmonary tuberculosis, T‐spot, CT imaging, colonoscopy, pathological features, acid‐fast bacilli and response to anti‐tuberculosis therapy (ATT).

A number of approaches have been utilized to generate antibodies to cancer cell surface receptors which can be used as potential therapeutics. A number of these therapeutic approaches, including antibody-drug conjugates, immunotoxins, and targeted nucleic acid delivery, require antibodies that not only bind receptor, but that also undergo internalization into the cell upon binding. We previously reported the ability to generate cancer cell binding and internalizing antibodies directly from human phage antibody libraries selected for internalization into cancer cell lines. While a number of useful antibodies have been generated using this approach, limitations include the inability to direct the selections to specific antigens and identifying the antigen bound by the antibodies. Here we show that these limitation can be overcome by using yeast displayed antigens known to be associated with a cell type to select the phage antibody output after several rounds of selection on a mammalian cell line. We used this approach to generate several human phage antibodies to yeast displayed EphA2 and CD44. The antibodies bound both yeast displayed and mammalian cell surface antigen and were endocytosed upon binding to mammalian cells. This approach is generalizable to many mammalian cell surface proteins, results in the generation of functional internalizing antibodies, and does not require antigen expression and purification for antibody generation.