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This review provides an overview of the latest research progress in mRNA structural optimization strategies and their delivery systems, and discusses key considerations for their future clinical use.

A laccase catalyzed colorimetric biosensing approach is promising for the detection of pheochromocytoma biomarkers, yet suffers from the poor stability of enzymes and high cost for production. Here we report for the first time an easy to produce, cheap, stable and reliable laccase-mimicking CuCoFe-LDHzyme, which can catalyze the oxidation of pheochromocytoma biomarkers to form a chromogenic product for smartphone-based colorimetric detection.

Perturbations in mitochondrial membrane stability lead to cytochrome c release and induce caspase-dependent apoptosis. Using synthetic smart chemicals with changeable physicochemical properties to interfere the mitochondrial membrane stability has not yet been reported. Here we show that a thermosensitive anchor-polymer-peptide conjugate (anchor-PPC) destabilizes mitochondrial membranes upon

Accurate and non-invasive monitoring of allograft posttransplant is essential for early detection of acute cellular rejection and determines the long-term survival of the graft. Clinically, tissue biopsy is the most effective approach for diagnosing transplant rejection. Nonetheless, the procedure is invasive and potentially triggers organ failure. This work aims to design and apply GzmB-responsive nanosensors (GBRNs) that can readily size-change in graft tissues. Subsequently, we investigate the activity of serine protease granzyme B by generating a direct colorimetric urinary readout for non-invasive detection of transplant rejection in under 1 h. In preclinical heart graft mice models of transplant rejection, GBRNs were cleaved by GzmB and excreted by the kidneys via accurate nanometre-size glomerular filtration. By exploiting the catalytic activity of ultrasmall gold nanoclusters, GBRNs urinalysis promotes ultrasensitive surveillance of rejection episodes with a receiver operator characteristic curve area under the curve of 0.896 as well as a 95% confidence interval of about 0.7701-1.000. Besides, the catalytic activity of gold nanoclusters in urine can be detected at point-of-care testing to predict the immunity responses in mice with insufficient immunosuppressive therapy. Therefore, this non-invasive, sensitive, and quantitative method is a robust and informative approach for rapid and routine monitoring of transplant allografts without invasive biopsy.

Cancer vaccines have exhibited immense potential in cancer treatment. Through activating the host's immune system, vaccines stimulate extensive functional T cells to eliminate cancer. However, the therapeutic efficacy of cancer vaccines is limited by their inferior lymph node delivery and inadequate uptake of dendritic cells. Herein, we propose an in situ phase transitional strategy on vaccine manufacturing to maximally enhance lymph node drainage while ensuring adequate dendritic cell uptake. The phase transitional vaccines, with dynamic size modulation property, retain a small size (24.4 ± 3.1 nm) during lymph node draining then transform into larger particles (483.0 ± 41.6 nm) on-site by external signal input. Results show that this strategy induced rapid and robust immune response in a mouse melanoma tumor model. Furthermore, a stronger humoral immune response was observed in mice when immunized with MHC-II restricted antigen, which demonstrated that lymph node-targeted cancer vaccine delivery could be effectively manipulated through dynamic size modulation.

Cellular immunotherapeutics aim to employ immune cells as anticancer agents. Ex vivo engineering of dendritic cells (DCs), the initial role of an immune response, benefits tumor elimination by boosting specific antitumor responses. However, directly activating DCs in vivo is less efficient and therefore quite challenging. Here, we designed a nanoactivator that manufactures DCs through autophagy upregulating in vivo directly, which lead to a high-efficiency antigen presention of DCs and antigen-specific T cells generation. The nanoactivator significantly enhances tumor antigen cross-presentation and subsequent T cell priming. Consequently, in vivo experiments show that the nanoactivators successfully reduce tumor growth and prolong murine survival. Taken together, these results indicate in situ DCs manipulation by autophagy induction is a promising strategy for antigen presentation enhancement and tumor elimination.

The blockade of PD-1/PD-L1 interaction by peptide antagonists can unleash and enhance pre-existing anti-cancer immune responses of T cells to eradicate cancer cells. However, low proteolytic stability is the “Achilles' Heel” of peptides. Here, we first report a nanoantagonist with a physiological temperature sensitive nanophase-segregated surface that exhibits significantly enhanced blood circulation, peptide stability and PD-L1 immune checkpoint blockade efficacy. Thermosensitive polymers with different phase transition temperatures (Tt) are used to form the nanophase-segregated surface on an Au nanorod core. Importantly, the nanophase-segregated surface aids the nanoantagonist to resist protein adsorption and enhance the systemic stability of the linked peptides. Finally, the as-designed nanoantagonist effectively blocks PD-1/PD-L1 interaction in vitro and in vivo, enhances the pre-existing CD8+ T cell tumor destruction capability and inhibits tumor growth. This study offers a new strategy for designing nano-formulations for cancer immunotherapy.

Cancer metastasis is one of the major factors contributing to high mortality, and here we designed and synthesized a peptide cross-linked nanogel for hydrophilic functional molecule encapsulation and tumor metastasis inhibition. In this investigation, matrix metalloproteinase-2 (MMP2)-responsive peptide cross-linker is prepared by coupling acrylate-functional groups at both peptide terminals. The peptide cross-linked nanogel is then synthesized by free radical precipitation polymerization using N-isopropylacrylamide as the scaffold. Meanwhile, the hydrophilic tumor metastasis inhibition peptide P-5m is encapsulated into the nanogel in the one-pot synthesis step without complex cooperation. Importantly, the size-uniformed and narrow-distributed nanogel exhibits high P-5m loading capacity (43.4%). Interestingly, the nanogel is stable in vitro and in vivo, showing excellent and specific MMP2-triggered payload release property. As expected, the nanogel suppresses cancer cell migration and invasion in high per...

Intracellular construction of nanoaggregates from synthetic molecules to mimic natural ordered superstructures has gained increasing attention recently. Here, we develop an endogenous stimuli-induced aggregation (eSIA) approach to construct functional nanoaggregates for sensing and monitoring cellular physiological processes in situ. We design a series of thermosensitive polymer-peptide conjugates (PPCs), which are capable of constructing nanoaggregates in cells based on their isothermal phase transition property. The PPCs are composed of three moieties (i.e., a thermoresponsive polymer backbone, a grafted peptide, and a signal-molecule label). The bioenvironment-associated phase transition behavior of PPCs are carefully studied by consideration of various crucial parameters such as chain length, hydrophilicity, ratio of grafted peptides, and concentration. Intriguingly, under the specific intracellular stimulus, the PPCs are tailored and simultaneously form nanoaggregates exhibiting long-term retention effect, which enables specific identification and quantification of endogenous factors. This general approach is expected for high-performance in situ sensing and dynamic monitoring of disease progression in living subjects.

Achieving the activation of drugs within cellular systems may provide targeted therapies. Here we construct a tumour-selective cascade activatable self-detained system (TCASS) and incorporate imaging probes and therapeutics. We show in different mouse models that the TCASS system accumulates in solid tumours. The molecules show enhanced accumulation in tumour regions via the effect of recognition induced self-assembly. Analysis of the molecular penetration in tumour tissue shows that in vivo self-assembly increases the penetration capability compared to typical soft or hard nanomaterials. Importantly, the in vivo self-assembled molecules exhibit a comparable clearance pathway to that of small molecules, which are excreted from organs of the reticuloendothelial system (liver and kidney), while are relatively slowly eliminated from tumour tissues. Finally, this system, combined with the NIR probe, shows high specificity and sensitivity for detecting bladder cancer in isolated intact patient bladders., The activation of drugs within cellular systems may provide targeted therapies for cancer. Here, the authors make a drug delivery system that is activated within the cell and exploits XIAP expression to cleave a linker region, resulting in the self-assembly of the system and drug release within cancer cells.

Thermoresponsive polymeric assemblies are fabricated from thermoresponsive polymers based on the soluble to insoluble transition at the phase transition temperature. The architecture of the self-assemblies lies in the molecular level and influenced by the structural change of the thermoresponsive polymers. The formed nanoassemblies endow excellent biofunctions for biomedical applications. Typical thermoresponsive polymers are reviewed in this chapter. The design concept and key factors to influence the thermal behavior are also discussed and summarized. As the sprouting and promising field, in vivo self-assembled thermoresponsive polymeric assemblies are also discussed in this chapter.

Topological structures of bio-architectonics and bio-interfaces play major roles in maintaining the normal functions of organs, tissues, extracellular matrix, and cells. In-depth understanding of natural self-assembly mechanisms and mimicking functional structures provide us opportunities to artificially control the natural assemblies and their biofunctions. Here, we report an intracellular enzyme-catalyzed polymerization approach for efficient synthesis of polypeptides and in situ construction of topology-controlled nanostructures. We reveal that the phase behavior and topological structure of polypeptides are encoded in monomeric peptide sequences. Next, we elucidate the relationship between polymerization dynamics and their temperature-dependent topological transition in biological conditions. Importantly, the linearly grown elastin-like polypeptides are biocompatible and aggregate into nanoparticles that exhibit significant molecular accumulation and retention effects. However, 3D gel-like structures with thermo-induced multi-directional traction interfere with cellular fates. These findings allow us to exploit new nanomaterials in living subjects for biomedical applications., The intracellular topology of a nanostructure plays a major role in its interactions with the cell and accordingly, its biological applications. Here, the authors design peptides that intracellularly polymerize into elastin-like polypeptides and assemble into various topologies, each of which exhibits a distinct set of biological functions.

Posterior capsule opacification (PCO) is the most common complication after cataract surgery. So far, the only method for PCO treatment is the precisely focused laser surgery. However, it causes severe complications such as physical damages and neuron impairments. Here, a nanostructured photothermal ring integrated intraocular lens (Nano-IOLs) is reported, in which the rim of commercially available IOLs (C-IOLs) is decorated with silica coated Au nanorods (Au@SiO2 ), for high-efficient prevention of PCO after cataract surgery. The Nano-IOLs is capable of eliminating the residual lens epithelial cells (LECs) around Nano-IOLs under mild laser treatment and block the formation of disordered LECs fibrosis, which eventually leads to the loss of vision. The Nano-IOLs shows good biocompatibility as well as extraordinary region-confined photothermal effect. In vivo studies reveal that PCO occurrence in rabbit models is about 30%-40% by using Nano-IOLs, which is significantly lower than the control group that treated with C-IOLs (100% PCO occurrence) 30 d postsurgery. To the best of our knowledge, it is the first example to integrate nanotechnology with intraocular implants aiming to clinically relevant PCO. Our findings indicate that spatial controllability of photothermal effect from nanomaterials may provide a unique way to intervene the PCO-induced loss of vision.

Autophagic therapy is regarded as a promising strategy for disease treatment. Appropriate autophagy regulations in vivo play a crucial role in translating this new concept from benchside to bedside. So far, emerging technologies are required to spatially and quantitatively monitor autophagic process in vivo in order to minimize the cytotoxity concerns associated with autophagy-mediated therapy. We successfully demonstrate the "proof-of-concept" study on autophagy-mediated chemotherapy in mice. Here, we describe a photoacoustic (PA) nanoprobe based on "in vivo self-assembly" idea for real-time and quantitative detection of autophagy in mice for the first time. The purpurin-18 (P18) monomer is connected to hydrophilic poly(amidoamine) dendrimer (4th generation) through a peptide (GKGSFGFTG) that can be cleaved by an autophagy-specific enzyme, i.e., ATG4B, consequently resulting in aggregation of P18 and enhanced PA signals. Based on this aggregation-induced "turn-on" PA signals, we noninvasively determine the ATG4B activity for monitoring autophagy of tumor in vivo. According to the results of PA imaging, we could optimize chemotherapy efficacy through precisely modulating autophagy, which thereby decrease systemic toxicity from chemotherapeutics and autophagy inhibitors. We envision it will pave the way for developing autophagy-based treatment of diseases in the future.

Autophagy plays a crucial role in the metabolic process. So far, conventional methods are incapable of rapid, precise, and real-time monitoring of autophagy in living objects. Herein, we describe an in situ intracellular self-assembly strategy for quantitative and temporal determination of autophagy in living objectives. The intelligent building blocks (DPBP) are composed by a bulky dendrimer as a carrier, a bis(pyrene) derivative (BP) as a signal molecule, and a peptide linker as a responsive unit that can be cleaved by an autophagy-specific enzyme, i.e., ATG4B. DPBP maintains the quenched fluorescence with monomeric BP. However, the responsive peptide is specifically tailored upon activation of autophagy, resulting in self-aggregation of BP residues which emit a 30-fold enhanced fluorescence. By measuring the intensity of fluorescent signal, we are able to quantitatively evaluate the autophagic level. In comparison with traditional techniques, such as TEM, Western blot, and GFP-LC3, the reliability and accuracy of this method are finally validated. We believe this in situ intracellular self-assembly strategy provides a rapid, effective, real-time, and quantitative method for monitoring autophagy in living objects, and it will be a useful tool for autophagy-related fundamental and clinical research.

We report a convenient synthetic approach for one-pot preparation of poly(β-amino ester)s copolymerized with peptides. A family of copolymers with tertiary amine groups was synthesized by copolymerizing di(ethylene glycol) diacrylate (DEDA), poly(ethylene glycol) diacrylate (PEGDA), 3-(diethylamino)propylamine (DEPA) and GGRGD peptides using the Michael addition reaction. The hydrophobic/hydrophilic properties of the resulting copolymers are adjusted by altering the feed ratios of DEDA and PEGDA. The copolymers self-assembled into nanoparticles with sizes around 60–140 nm in aqueous media, which were confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM) techniques. The copolymers exhibit pH sensitive properties upon introduction of DEPA moieties, which were proved by pyrene fluorescence and pH titration measurements. The acid-triggered dissociation behaviors of the nanoparticles were studied by DLS and Nile red (NR) release experiments, revealing that the sizes of dissociated copolymer nanoparticles were closely relevant to their compositions. The nanoparticles can load the hydrophobic anticancer drug, i.e., doxorubicin (DOX). The DOX-loaded nanoparticles were stable in a neutral phosphate buffer solution with a payload leakage less than 20% at 37 °C. However, a significant acid-triggered DOX release was accomplished at pH 5.0 with release efficiency up to 60–80%. Because of the decoration of Arg-Gly-Asp (RGD) peptides onto the poly(β-amino ester)s, the DOX-encapsulated nanoparticles formed by poly(RGD-co-β-amino ester)s can be internalized by cancer cells via an αvβ3 integrin-mediated endocytosis pathway and accumulated in the lysosomes that provide an acidic environment to promote the release of DOX. Finally, the DOX-encapsulated copolymer nanoparticles with the targeted RGD peptide exhibited higher efficiency to kill U87 human glioblastoma cancer cells than that without RGD, which was further proved by cellular uptake of DOX-loaded nanoparticles.

Tumor-associated macrophages (TAMs) are of great interest in cancer immunology as they play an important role in the tumor microenvironment as cancer stromal cells recruited from circulating monocytes. TAMs are closely associated with tumor progression, including initiation, trophic growth, metabolism, angiogenesis, and metastasis; moreover, in clinical practice, their quantity can be related to poor prognosis. Fundamental and translational studies imply that TAMs are one of the most promising targets in tumor therapy. Herein, the biological origination and classification of TAMs, which correspond to their functions and differentiations, are reviewed in detail. In addition, recent basic research and clinical preprocess of TAMs in tumor immunotherapy are also discussed. Finally, the advances in the use of nanotechnology and TAMs for tumor therapy are discussed. This review focuses on the background and status of basic research and clinical significance of TAMs, points out the potential of TAMs in tumor immunological therapy, and clarifies the possibility of translation TAM-targeting therapies in medicine.

Immunotherapy has shown promising treatment effects for a variety of cancers. However, the immune treatment efficiency for solid tumors is limited owing to insufficient infiltration of immune cells into solid tumors. The conversion of tumor-supportive macrophages to tumor-suppressive macrophages, inducing the functional reversal of macrophages, is an effective method and contributes to a subsequent antitumor response. The current challenge in the field is the poor distribution and systemic side effects associated with the use of cytokines. As a solution to this issue, we designed and synthesized microenvironment-responsive nanoparticles (P) with IL-12 payload (IL-12⊂P1). These nanoparticles could promote the systemic administration and release of IL-12 in the tumor microenvironment, and the locally responsive property of IL-12⊂P1 could subsequently re-educate tumor-associated macrophages (TAMs). In particular, our results illustrated the great therapeutic effects derived from the functional conversion of macrophages. Our strategy was to design a microenvironment-responsive material for local macrophage modification to overcome the physiological barrier of solid tumors. The shifting of macrophage phenotypes via IL-12⊂P1 achieved immunomodulation in the microenvironment for cancer therapy, with negligible cytotoxicity. We expect that the functional regulation of TAMs by pH-responsive nanomaterials is a promising therapeutic approach for cancer immunotherapy.

Bioinspired design concept has been recognized as one of the most promising strategies for discovering new biomaterials. However, smart biomaterials that are of growing interests in biomedical field need biological processability to meet their emergent applications in vivo. Herein, a new bio-orthogonally deciphered approach has been demonstrated for modulating optical properties of nanomaterials in living systems. The self-assembled nanoemitters based on cyanine-pyrene molecule 1 with inert optical property are designed and prepared. The structure and optical feature of the nanoemitters 1 can be efficiently and reliably modulated by a unique bio-orthogonal mechanism with abundant glutathione (GSH) as an activator. As a result, the self-assembled nanoemitters 1 spontaneously exhibits binary emissions for high-performance tumor imaging in vivo. We believe that this bio-orthogonally deciphered strategy opens a new avenue for designing variable smart biomaterials or devices in biomedical applications.

We herein report a thermocontrolled strategy for realizing in situ conformational transition of polymer–peptide conjugates at cell surfaces to manipulate and monitor HER2 receptor clustering, which finally result in effective breast cancer cell proliferation inhibition. Functional paring motifs (HBP) are covalently linked to a synthetic thermoresponsive polymer PNIPAAm to incorporate temperature control properties to HER2 targeting peptide. At 40 °C, the PNIPAAm polymers collapse and act as a “shield” to block the aggregation of HBP. Upon cooling to 35 °C, polymers are in their extended state and HBP are expose in aqueous and aggregate subsequently with enhanced fluorescence, allowing for promoting and in situ monitoring of receptor clustering. Ultimately, HER2 receptor clustering leads to cytoplasmic domain phosphorylation, which further results in effective cancer cell proliferation inhibition. We envision that this useful approach has the potential to be applied for molecule-targeted tumor therapy.

In drug delivery systems, pH-sensitive polymers are commonly used as drug carriers, and significant efforts have been devoted to the aspects of controlled delivery and release of drugs. However, few studies address the possible autophagic effects on cells. Here, for the first time, using a fluorescent autophagy-reporting cell line, this study evaluates the autophagy-induced capabilities of four types of pH-sensitive polymeric nanoparticles (NPs) with different physical properties, including size, surface modification, and pH-sensitivity. Based on experimental results, this study concludes that pH-sensitivity is one of the most important factors in autophagy induction. In addition, this study finds that variation of concentration of NPs could cause different autophagic effect, i.e., low concentration of NPs induces autophagy in an mTOR-dependent manner, but high dose of NPs leads to autophagic cell death. Identification of this tunable autophagic effect offers a novel strategy for enhancing therapeutic effect in cancer therapy through modulation of autophagy.

According to the color development reaction between starch/iodine reagent and products which obtained by fumigating melamine with chlorine, a method for determination of melamine in milk was put forward. The conditions of method were researched. The best conditions are as follows. Volume ratio of milk and extraction agent is 1:1. 5, dissolved with ultrasonic washer for 5 minutes, centrifugal separation 4000r/min for 5 minutes, extracted by C008 cation exchange resin column. The results are as follows: detection limit is 10mg/L, the linear range is 25-250 mg/L, related coefficient r is 0.994, coefficient of recovery is 94%-110%, and relatively standard deviation is 0.9%. This method is easy handling, cheap equipment, good practicability and recovery, can be used as low cost detection method.

A universal strategy for efficient, mild, and purification-free synthesis and in situ screening of functional polymer-peptide nanomaterials is described. More than 1000 polymer-peptide conjugates (PPCs) with various chemical structures, compositions, and therapeutic efficacy are created. According to this strategy, the structure-function relationship of the PPCs is revealed, and the antitumor efficacies of the top performing PPCs are evaluated in vivo.

Supramolecular self-assemblies with various nanostructures in organic and aqueous solutions have been prepared with desired functions. However, in situ construction of self-assembled superstructures in physiological conditions to achieve expected biological functions remains a challenge. Here, we report a supramolecular system to realize the in situ formation of nanoaggregates in living cells. The bis(pyrene) monomers were dispersed inside of hydrophobic domains of pH-sensitive polymeric micelles and delivered to the lysosomes of cells. In the acidic lysosomes, the bis(pyrene) monomers were released and self-aggregated with turn-on fluorescence. We envision this strategy for in situ construction of supramolecular nanostructures in living cells will pave the way for molecular diagnostics in the future.

We report a supramolecular approach for preparation of photostable NIR nanovesicles based on a cyanine dye derivative as a photoacoustic (PA) contrast agent for high-performance nano-imaging.

An assembly-induced retention effect for enhanced tumor photoacoustic (PA) imaging and therapeutics is described. A responsive small-molecule precursor is prepared that simultaneously self-assembles into nanofibers in tumor sites that exhibit an assembly-induced retention effect, which results in an improved PA imaging signal and enhanced therapeutic efficacy. This successful proof-of-concept study paves the way to develop novel supramolecular biomaterials for cancer diagnostics and therapeutics.

A peptide-conjugated poly(β-amino ester) that self-assembles into micelle-like nanoparticles is prepared by a convenient and modular supramolecular approach. The polymer-beclin-1 (P-Bec1) nanoparticles display enhanced cytotoxicity to breast cancer cells through induction of autophagy. This approach overcomes two major limitations of the haploinsufficient tumor suppressor Bec1 compared to small-molecule drugs: poor delivery to tumors owing to enzymatic degradation, and unstable, non-specific bio-distribution and targeting in the tumor tissues.

Urinary tract infections are typical bacterial infections which result in a number of economic burdens. With increasing antibiotic resistance, it is urgent that new approaches are explored that can eliminate pathogenic bacteria without inducing drug resistance. Antimicrobial photodynamic therapy (PDT) is a new promising tactic. It is a gentle in situ photochemical reaction in which a photosensitizer (PS) generates reactive oxygen species (ROS) under laser irradiation. In this work, we have demonstrated Chlorin e6 (Ce6) encapsulated charge-conversion polymeric nanoparticles (NPs) for efficiently targeting and killing pathogenic bacteria in a weakly acidic urinary tract infection environment. Owing to the surface charge conversion of NPs in an acidic environment, the NPs exhibited enhanced recognition for Gram-positive (ex. S. aureus) and Gram-negative (ex. E. coli) bacteria due to the charge interaction. Also, those NPs showed significant antibacterial efficacy in vitro with low cytotoxicity. The MIC value of NPs to E. coli is 17.91 μg ml(-1), compared with the free Ce6 value of 29.85 μg ml(-1). Finally, a mouse acute cystitis model was used to assess the photodynamic therapy effects in urinary tract infections. A significant decline (P < 0.05) in bacterial cells between NPs and free Ce6 occurred in urine after photodynamic therapy treatment. And the plated counting results revealed a remarkable bacterial cells drop (P < 0.05) in the sacrificed bladder tissue. Above all, this nanotechnology strategy opens a new door for the treatment of urinary tract infections with minimal side effects.