In biomedical science among several other growing fields, the detection of specific biological agents or biomolecular markers, from biological samples is crucial for early diagnosis and ...decision-making in terms of appropriate treatment, influencing survival rates. In this regard, immunosensors are based on specific antibody-antigen interactions, forming a stable immune complex. The antigen-specific detection antibodies (i.e., biomolecular recognition element) are generally immobilized on the nanomaterial surfaces and their interaction with the biomolecular markers or antigens produces a physico-chemical response that modulates the signal readout. Lowering the detection limits for particular biomolecules is one of the key parameters when designing immunosensors. Thus, their design by combining the specificity and versatility of antibodies with the intrinsic properties of nanomaterials offers a plethora of opportunities for clinical diagnosis. In this review, we show a comprehensive set of recent developments in the field of nanoimmunosensors and how they are progressing the detection and validation for a wide range of different biomarkers in multiple diseases and what are some drawbacks and considerations of the uses of such devices and their expansion.
Advances in nanofabrication methods have enabled the tailoring of new strategies towards the controlled production of nanoparticles with attractive applications in healthcare. In many cases, their ...characterisation remains a big challenge, particularly for small-sized functional nanoparticles of 5 nm diameter or smaller, where current particle sizing techniques struggle to provide the required sensitivity and accuracy. There is a clear need for the development of new reliable characterisation approaches for the physico-chemical characterisation of nanoparticles with significant accuracy, particularly for the analysis of the particles in the presence of complex biological fluids. Herein, we show that the Differential Centrifugal Sedimentation can be utilised as a high-precision tool for the reliable characterisation of functional nanoparticles of different materials. We report a method to correlate the sedimentation shift with the polymer and biomolecule adsorption on the nanoparticle surface, validating the developed core-shell model. We also highlight its limit when measuring nanoparticles of smaller size and the need to use several complementary methods when characterising nanoparticle corona complexes.
Key practical challenges such as understanding the immunological processes at the nanoscale and controlling the targeting and accumulation of nano-objects in vivo now further stimulate efforts to ...underpin phenomenological knowledge of the nanoscale with more mechanistic and molecular insight. Thus, the question as to what constitutes nanoscale biological identity continues to evolve. Certainly nanoparticles in contact with a complex biological milieu develop a biological identity, differing from the original nanomaterial, now referred to as the “biomolecular corona”. However, this surface-adsorbed layer of biomolecules may in some circumstance lead to different forms of receptor–particle interactions not evident only from the identity of the surface-adsorbed biomolecules and hard to predict or detect by current physicochemical methods. Here we show that scavenger receptors may recognize complex as yet unidentified biomolecular surface layer motifs, even when no current physicochemical analysis is capable of doing so. For instance, fluorescently labeled SiO2 nanoparticles in a biological milieu are strongly recognized by the macrophage receptor with collagenous structure (MARCO) in even dense biological media (human serum) apparently using a form of binding with which most of the MARCO’s known ligands (e.g., LPS, modified LDL) fail to compete. Such observations may suggest the need for a much stronger emphasis on nanoscale receptor–corona and other biomolecular interaction studies if one wishes to unravel how biomolecular recognition drives outcomes in the nanoscale biological domain.
The transport and the delivery of drugs through nanocarriers is a great challenge of pharmacology. Since the production of liposomes to reduce the toxicity of doxorubicin in patients, a plethora of ...nanomaterials have been produced and characterized. Although it is widely known that elementary properties of nanomaterials influence their in vivo kinetics, such interaction is often poorly investigated in many preclinical studies. The present study aims to evaluate the actual effect of size and shape on the biodistribution of a set of gold nanoparticles (GNPs) after intravenous administration in mice. To this goal, quantitative data achieved by inductively coupled plasma mass spectrometry and observational results emerging from histochemistry (autometallography and enhanced dark-field hyperspectral microscopy) were combined. Since the immune system plays a role in bionano-interaction we used healthy immune-competent mice. To keep the immune surveillance on the physiological levels we synthesized endotoxin-free GNPs to be tested in specific pathogen-free animals. Our study mainly reveals that (a) the size and the shape greatly influence the kinetics of accumulation and excretion of GNPs in filter organs; (b) spherical and star-like GNPs showed the same percentage of accumulation, but a different localization in liver; (c) only star-like GNPs are able to accumulate in lung; (d) changes in the geometry did not improve the passage of the blood brain barrier. Overall, this study can be considered as a reliable starting point to drive the synthesis and the functionalization of potential candidates for theranostic purposes in many fields of research.
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The engagement with the immune system is one of the main cornerstones in the development of nanotechnologies for therapy and diagnostics. Recent advances have made possible the tuning ...of features like size, shape and biomolecular modifications that influence such interactions, however, the capabilities for immune modulation of nanoparticles are still not well defined and exploited. This review focuses on recent advances made in preclinical research for the application of nanoparticles to modulate immune responses, and the main features making them relevant for such applications. We review and discuss newest evidence in the field, which include in vivo experiments with an extensive physicochemical characterization as well as detailed study of the induced immune response. We emphasize the need of incorporating knowledge about immune response development and regulation in the design and application of nanoparticles, including the effect by parameters such as the administration route and the differential interactions with immune subsets.
Since it is now possible to make, in a controlled fashion, an almost unlimited variety of nanostructure shapes, it is of increasing interest to understand the forms of biological control that ...nanoscale shape allows. However, a priori rational investigation of such a vast universe of shapes appears to present intractable fundamental and practical challenges. This has limited the useful systematic investigation of their biological interactions and the development of innovative nanoscale shape-dependent therapies. Here, we introduce a concept of biologically relevant inductive nanoscale shape discovery and evaluation that is ideally suited to, and will ultimately become, a vehicle for machine learning discovery. Combining the reproducibility and tunability of microfluidic flow nanochemistry syntheses, quantitative computational shape analysis, and iterative feedback from biological responses in vitro and in vivo, we show that these challenges can be mastered, allowing shape biology to be explored within accepted scientific and biomedical research paradigms. Early applications identify significant forms of shape-induced biological and adjuvant-like immunological control.
Lymphocyte migration is essential for adaptive immune surveillance. However, our current understanding of this process is rudimentary, because most human studies have been restricted to immunological ...analyses of blood and various tissues. To address this knowledge gap, we used an integrated approach to characterize tissue-emigrant lineages in thoracic duct lymph (TDL). The most prevalent immune cells in human and non-human primate efferent lymph were T cells. Cytolytic CD8+ T cell subsets with effector-like epigenetic and transcriptional signatures were clonotypically skewed and selectively confined to the intravascular circulation, whereas non-cytolytic CD8+ T cell subsets with stem-like epigenetic and transcriptional signatures predominated in tissues and TDL. Moreover, these anatomically distinct gene expression profiles were recapitulated within individual clonotypes, suggesting parallel differentiation programs independent of the expressed antigen receptor. Our collective dataset provides an atlas of the migratory immune system and defines the nature of tissue-emigrant CD8+ T cells that recirculate via TDL.
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•Comprehensive map of the human immune system in thoracic duct•Non-cytolytic effector memory CD8+ T cells primarily recirculate via thoracic duct•Cytolytic CD8+ T cells confined to intravascular circulation at steady state•Individual antigen-specific clones exhibit distinct migratory and functional capabilities
Buggert et al. provide a core signature that defines humantissue-emigrant CD8+ T cells under homeostatic conditions. They observe that cytolytic effector memory CD8+ T cells are primarily confined to peripheral blood and almost absent in thoracic duct lymph, indicating that distinct effector memory populations surveil blood and tissues.
CD8
T cell exhaustion is a hallmark of many cancers and chronic infections. In mice, T cell factor 1 (TCF-1) maintains exhausted CD8
T cell responses, whereas thymocyte selection-associated HMG box ...(TOX) is required for the epigenetic remodeling and survival of exhausted CD8
T cells. However, it has remained unclear to what extent these transcription factors play analogous roles in humans. In this study, we mapped the expression of TOX and TCF-1 as a function of differentiation and specificity in the human CD8
T cell landscape. Here, we demonstrate that circulating TOX
CD8
T cells exist in most humans, but that TOX is not exclusively associated with exhaustion. Effector memory CD8
T cells generally expressed TOX, whereas naive and early-differentiated memory CD8
T cells generally expressed TCF-1. Cytolytic gene and protein expression signatures were also defined by the expression of TOX. In the context of a relentless immune challenge, exhausted HIV-specific CD8
T cells commonly expressed TOX, often in clusters with various activation markers and inhibitory receptors, and expressed less TCF-1. However, polyfunctional memory CD8
T cells specific for cytomegalovirus (CMV) or Epstein-Barr virus (EBV) also expressed TOX, either with or without TCF-1. A similar phenotype was observed among HIV-specific CD8
T cells from individuals who maintained exceptional immune control of viral replication. Collectively, these data demonstrate that TOX is expressed by most circulating effector memory CD8
T cell subsets and not exclusively linked to exhaustion.
Corona disease 2019 (COVID‐19) affects multiple organ systems. Recent studies have indicated perturbations in the circulating metabolome linked to COVID‐19 severity. However, several questions ...pertain with respect to the metabolome in COVID‐19. We performed an in‐depth assessment of 1129 unique metabolites in 27 hospitalized COVID‐19 patients and integrated results with large‐scale proteomic and immunology data to capture multiorgan system perturbations. More than half of the detected metabolic alterations in COVID‐19 were driven by patient‐specific confounding factors ranging from comorbidities to xenobiotic substances. Systematically adjusting for this, a COVID‐19‐specific metabolic imprint was defined which, over time, underwent a switch in response to severe acute respiratory syndrome coronavirus‐2 seroconversion. Integration of the COVID‐19 metabolome with clinical, cellular, molecular, and immunological severity scales further revealed a network of metabolic trajectories aligned with multiple pathways for immune activation, and organ damage including neurological inflammation and damage. Altogether, this resource refines our understanding of the multiorgan system perturbations in severe COVID‐19 patients.
Through in‐depth metabolomics analysis combined with clinical metadata, we first define a COVID‐19‐specific metabolic imprint. By integrating this with large‐scale proteomic and flow cytometry data, metabolic trajectories associated with immune activation and organ damage are identified. This resource illustrates ongoing multisystem perturbations in severe COVID‐19 patients.
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