A human endogenous protein exerts multi-role biomimetic chemistry in synthesis of paramagnetic gold nanostructures for tumor bimodal imaging

Biomimetic nanomaterial-facilitated oxygen generation strategies for enhancing tumour treatment outcomes

Hypoxia, as a typical hallmark of the tumour microenvironment (TME), has been verified to exist in most malignancies and greatly hinders the outcome of tumour treatments, including chemotherapy, photodynamic therapy, radiotherapy, and immunotherapy. Various approaches to alleviate tumour hypoxia have been reported. Among them, biomimetic nanomaterial-facilitated tumour oxygenation strategies, based on the engagement of human endogenous proteins, red blood cells, the cell membrane, and catalase, are the most impressive due to their excellent tumour active-targeting ability and superior tumour-selective capability, which, however, have not yet been systematically reviewed. Herein, we are ready to describe the current progress in biomimetic nanomaterial-facilitated tumour oxygenation strategies and corresponding improvements in tumour treatment outputs. In this review, the underlying mechanism behind the superior effect of these biomimetic nanomaterials, compared with other materials, on alleviating the hypoxic TME is highlighted. Additionally, the ongoing problems and potential solutions are also discussed.

Nanoconjugates based on a novel organic-inorganic hybrid silsesquioxane and gold nanoparticles as hemocompatible nanomaterials for promising biosensing applications

A new hybrid organic-inorganic silsesquioxane material, 3-n-propyl(2-amino-4-methyl)pyridium chloride (SiAMPy⁺Cl^-), was synthesized and successfully applied for the synthesis of stable nanoconjugates with gold nanoparticles (AuNPs-SiAMPy⁺). SiAMPy⁺Cl^- was obtained through a simple sol-gel procedure by using chloropropyltrimetoxysilane and tetraethylorthosilicate as precursors and 2-amino-4-methylpyridine as the functionalizing agent. The resulting material was characterized by employing FTIR, XRD, and ¹H-, ¹³C-, and ²⁹Si-NMR spectroscopy. The synthesis of AuNPs-SiAMPy⁺ nanoconjugates was optimized through a 2³ full factorial design. UV-VIS, FTIR, TEM, DLS, and ζ-potential measurements were used to characterize the nanoconjugates, which presented a spherical morphology with an average diameter of 5.8 nm. To investigate the existence of toxic effects of AuNPs-SiAMPy⁺ on blood cells, which is essential for their future biomedical applications, toxicity assays on human erythrocytes and leukocytes were performed. Interestingly, no cytotoxic effects were observed for both types of cells. The nanoconjugates were further applied in the construction of electrochemical immunosensing devices, aiming the detection of anti-Trypanosoma cruzi antibodies in serum as biomarkers of Chagas disease. The AuNPs-SiAMPy⁺ significantly enhanced the sensitivity of the biodevice, which was able to discriminate between anti-T. cruzi positive and negative serum samples. Thus, the AuNPs-SiAMPy⁺-based biosensor showed great potential to be used as a new tool to perform fast and accurate diagnosis of Chagas disease. The promising findings described herein strongly confirm the remarkable potential of SiAMPy⁺Cl^- to obtain nanomaterials, which can present notable biomedical properties and applications.

Construction of NaYF4 Library for Morphology-Controlled Multimodality Applications

Morphology and size of the nanoparticles are highly related to the properties; establishing a library to summarize the relationship between the morphology/size and property is very helpful for associated applications. However, the NaYF₄ library and thus the correlation between the morphology and property are still absent. Here NaYF₄ library is presented and their morphologies and structures are illustrated at atomic scale for the first time. How about the crystal formation affects the morphology is further used to guide the property. Through rational doping, upconversion luminescence, magnetic resonance (MR) and computed tomography are investigated with the nanoprisms, nanoflowers, and nanoplates as models to reveal the effect of the size and morphology. The difference of the properties provides strong evidence on the importance of the library. In particular, the "imperfect structure" of nanoflower is observed on atomic scale and enhances the MR response. The different upconversion intensity ratio for the emissions at 475 and 693 nm is observed from doped NaYF₄ with different morphology. Thus, controllable fabrication of NaYF₄ with desired morphology is indispensable to achieve the optimal properties as the guidance on how to choose matrix from the library to meet the specific applications.

Advantages of CT nano-contrast agent in tumor diagnosis: A retrospective study

The purpose of this retrospective study was to explore the advantages of computed tomography (CT) nano-contrast agent in tumor diagnosis.A total of 100 patients with malignant tumor who were diagnosed in Shaanxi Province Public Hospital between January 2018 and January 2019 were included in this retrospective study. They were randomly divided into observation and control groups with 50 patients in each group. The patients in the observation group used new type of nano-contrast agent for examination, and the patients in the control group used traditional iohexol contrast agent for examination. The detection rate, misdiagnosis rate, and incidence of adverse reactions were observed. In addition, single photon emission computed tomography or CT scan was performed on patients to observe the radioactive concentration.The detection rate was 100% in the observation group and 84% in the control group, and the difference between the 2 groups was statistically significant (χ2 = 8.763, P = .001). The incidence of adverse reactions was 2% in the observation group and 30% in the control group, and the difference between the 2 groups was significantly different (χ2 = 12.683, P = .000). The radioactive concentration in the observation group was markedly higher than that in the control group (t = 19.692, P = .001).The use of CT nano-contrast agent in tumor diagnosis had higher detection rate of tumor and radioactive concentration, and it had lower misdiagnosis rate and adverse reaction rate than traditional iohexol contrast agent.

Synthesis and Bioapplications of Ag2 S Quantum Dots with Near-Infrared Fluorescence

Quantum dots (QDs) with near-infrared fluorescence (NIR) are an emerging class of QDs with unique capabilities owing to the deeper tissue penetrability of NIR light compared with visible light. NIR light also effectively overcomes organism autofluorescence, making NIR QDs particularly attractive in biological imaging applications for disease diagnosis. Considering latest developments, Ag₂ S QDs are a rising star among NIR QDs due to their excellent NIR fluorescence properties and biocompatibility. This review presents the various methods to synthesize NIR Ag₂ S QDs, and systematically discusses their applications in biosensing, bioimaging, and theranostics. Major challenges and future perspectives concerning the synthesis and bioapplications of NIR Ag₂ S QDs are discussed.

Natural Phyto-Antioxidant Albumin Nanoagents to Treat Advanced Alzheimer's Disease

Phytotherapeutic approaches are of immense value in the treatment of advanced Alzheimer's disease (AD) because of their diverse biological components and potential multitarget mechanisms. In this study, quercetin, a natural neuroprotective flavonoid, was encapsulated in human serum albumin to obtain HSA@QC nanoparticles (HQ NPs) as a natural phyto-antioxidant albumin nanoagent for the treatment of advanced AD. HQ NPs showed excellent antioxidant effects and protected PC12 cells from H2O2-induced oxidative damage. The intranasal administration of HQ NPs in 11-month-old APP/PS1 mice, which represented advanced AD, effectively prevented the loss of body weight, increased survival rates, and significantly reduced oxidative stress, Aβ aggregation, neuronal apoptosis, and synaptic damage in the brain. It also ultimately reversed severely impaired cognitive function. In addition to their favorable anti-AD effects, HQ NPs exhibited excellent biosafety and biocompatibility owing to their natural composition and are expected to become an ideal choice for future drug development and clinical applications.

Nanotheranostic Application of Fluorescent Protein-Gold Nanocluster Hybrid Materials: A Mini-review

The gold nanoclusters (Au NCs) are a special kind of gold nanomaterial containing several gold atoms. Because of their small size and large surface area, Au NCs possess macroscopic quantum tunneling and dielectric domain effects. Furthermore, Au NCs fluorescent materials have longer luminous time and better photobleaching resistance compared with other fluorescent materials. The synthetic process of traditional Au NCs is complicated. Traditional Au NCs are prepared mainly by using polyamide amine type dendrites, and sixteen alkyl trimethylamine bromide or sulfhydryl small molecule as stabilizers. They are consequently synthesized by the reduction of strong reducing agents such as sodium borohydride. Notably, these materials are toxic and environmental-unfriendly. Therefore, there is an urgent need to develop more effective methods for synthesizing Au NCs via a green approach. On the other hand, the self-assembly of protein gold cluster-based materials, and their biomedical applications have become research hotspots in this field. We have been working on the synthesis, assembly and application of protein conjugated gold clusters for a long time. In this review, the synthesis and assembly of protein-gold nanoclusters and their usage in cell imaging and other medical research are discussed.

In Situ One-Pot Synthesis of Fe2O3@BSA Core-Shell Nanoparticles as Enhanced T1-Weighted Magnetic Resonance Imagine Contrast Agents

Ultra-small-sized iron oxide nanoparticles with good biocompatibility are regarded as promising alternatives for the gadolinium-based contrast agents, which are widely used as a positive contrast agent in magnetic resonance imaging (MRI). However, the current preparation of the iron oxide magnetic nanoparticles with small sizes usually involves organic solvents, increasing the complexity of hydrophilic ligand replacement and reducing the synthesis efficiency. It remains a great challenge to explore new iron oxide nanoparticles with good biocompatibility and a high T₁ contrast effect. Here, we reported a cage-like protein architecture self-assembled by approximately 6-7 BSA (bovine serum albumin) subunits. The BSA nanocage was then used as a biotemplate to synthesize uniformed and monodispersed Fe₂O₃@BSA nanoparticles with ultra-small sizes (∼3.5 nm). The Fe₂O₃@BSA nanoparticle showed a high r₁ value of 6.8 mM^-1 s^-1 and a low r₂/r₁ ratio of 10.6 at a 3 T magnetic field. Compared to Gd-DTPA, the brighter signal and prolonged angiographic effect of Fe₂O₃@BSA nanoparticles could greatly benefit steady-state and high-resolution imaging. The further in vivo and in vitro assessments of stability, toxicity, and renal clearance indicated a substantial potential as a T₁ contrast agent in preclinical MRI.

Biomimetic nanoarchitecturing: A disguised attack on cancer cells

With the changing face of healthcare, there is a demand for drug delivery systems that have increased efficacy and biocompatibility. Nanotechnology derived drug carrier systems were found to be ideal candidates to meet these demands. Among the vast number of nanosized delivery systems, biomimetic nanoparticles have been researched at length. These nanoparticles mimic cellular functions and are highly biocompatible. They are also able to avoid clearance by the reticuloendothelial system which increases the time spent by them in the systemic circulation. Additionally, their low immunogenicity and targeting ability increase their significance as drug carriers. Based on their core material we have summarized them as biomimetic inorganic nanoparticles, biomimetic polymeric nanoparticles, and biomimetic lipid nanoparticles. The core then may be coated using membranes derived from erythrocytes, cancer cells, leukocytes, stem cells, and other membranes to endow them with biomimetic properties. They can be used for personalized therapy and diagnosis of a large number of diseases, primarily cancer. This review summarizes the various therapeutic approaches using biomimetic nanoparticles along with their applications in the field of cancer imaging, nucleic acid therapy and theranostic properties. A brief overview about toxicity concerns related to these nanoconstructs has been added to provide knowledge about biocompatibility of such nanoparticles.

Seedless synthetic branched gold nanoshells for chemo-thermal antitumor therapy

Gold nanomaterials (GNMs) are used in photothermal therapy due to their superior optical properties and excellent biocompatibility. However, the complex preparation process involving seed-mediated growth limits further clinical applications of GNMs. Herein, a novel one-pot approach to rapidly prepare liposome-based branched gold nanoshells (BGNS) as an antitumor drug nanocarrier is reported. This efficient seedless synthesis realized tunable absorption peaks of BGNS through controlling the concentration of the Au precursor solution, obtaining high absorbance in the near-infrared (NIR) window to achieve a superior photothermal effect. Hyperthermia during NIR laser irradiation can ablate the tumor and trigger drug release to achieve combined treatment. After laser irradiation, the nanocarriers disintegrated into individual gold nanoparticles (size: about 8 nm), which can be metabolized by the kidneys. Cell experiments in vitro and experiments involving mice with tumors have confirmed that the nanodrugs have strong antitumor effects. Such a flexible method provides a universal approach for rapidly preparing liposome-based gold nanoshells, which have the potential for large-scale preparation for further clinical applications.

Peptide Nanotube-Templated Biomineralization of Cu2-x S Nanoparticles for Combination Treatment of Metastatic Tumor

1D peptide nanostructures (i.e., peptide nanotubes, PNTs) exhibit tunable chemo-physical properties and functions such as improved tissue adhesion, increased cellular uptake, and elongated blood circulation. In this study, the application of PNTs as a desirable 1D template for biomineralization of Cu_2-x S nanoparticles (Cu_2-x S NPs, x = 1-2) is reported. Monodisperse Cu_2-x S NPs are uniformly coated on the peptide nanotubes owing to the specific high binding affinity of Cu ions to the imidazole groups exposed on the surface of nanotubes. The Cu_2-x S NP-coated PNTs are further covalently grafted with an oxaliplatin prodrug (Pt-CuS-PNTs) to construct a versatile nanoplatform for combination cancer therapy. Upon 808 nm laser illumination, the nanoplatform induces significant hyperthermia effect and elicits reactive oxygen species generation through electron transfer and Fenton-like reaction. It is demonstrated that the versatile nanoplatform dramatically inhibits tumor growth and lung metastasis of melanoma in a B16-F10 melanoma tumor-bearing mouse model by combined photo- and chemotherapy. This study highlights the ability of PNTs for biomineralization of metal ions and the promising potential of such nanoplatforms for cancer treatment.

PEGylated gold nanorods are not cytotoxic to human endothelial cells but affect kruppel-like factor signaling pathway

Gold (Au) nanomaterials (NMs), particularly those with PEG surface functionalization, are generally considered to be biocompatible for biomedical applications due to relatively low cytotoxicity. Herein, we investigated the toxicity of PEGylated Au nanorods (NRs) to human umbilical vein endothelial cells (HUVECs), a commonly used in vitro model for human endothelium. We found a previously unknown effect that up to 10 μg/mL Au NRs, albeit not cytotoxic, decreased the mRNA and protein levels of kruppel-like factor 2 (KLF2), a transcription factor with well-documented vasoprotective effects. The results from PCR array showed that a number of genes associated with risk of cardiovascular diseases were altered by Au NRs, and several genes are downstream genes of KLF2 according to ingenuity pathway analysis (IPA). These effects could be observed with or without the presence of inflammatory stimuli lipopolysaccharide (LPS), which suggests a pre-existing inflammatory state is not required for Au NRs to alter KLF2 signaling pathway. We further identified that Au NRs significantly decreased eNOS mRNA/p-eNOS proteins as well as increased MCP-1 mRNA/sMCP-1 release, which are targets of KLF2. Combined, our data revealed a novel pathway that PEGylated Au NPs at non-cytotoxic concentrations might alter KLF leading to the increase of risk of cardiovascular diseases in human endothelial cells. Given the importance of KLF in vascular homeostasis, our data indicate that it is necessary to evaluate the influence of engineered NPs to KLF signaling pathways, especially for NPs with biomedical uses.

Recent advances of biomimetic nano-systems in the diagnosis and treatment of tumor

The lack of effective methods of diagnosis and treatment presents a major barrier to combat against tumor. The biomimetic concept is an emerging field that expresses great application potential in tumor fighting. Strategy for combining nano-systems with biomimetic technology has gained increasing attention that is proved bioinspired, environmentally benign, and promising. Herein, we provide an up-to-date review of biomimetic nano-systems as well as their applications in tumor therapy. In addition, the challenges and future directions of biomimetic nano-systems to achieve clinical translation are also pointed out.

Advances of nanotechnology in osteochondral regeneration

In the past few decades, nanotechnology has proven to be one of the most powerful engineering strategies. The nanotechnologies for osteochondral tissue engineering aim to restore the anatomical structures and physiological functions of cartilage, subchondral bone, and osteochondral interface. As subchondral bone and articular cartilage have different anatomical structures and the physiological functions, complete healing of osteochondral defects remains a great challenge. Considering the limitation of articular cartilage to self-healing and the complexity of osteochondral tissue, osteochondral defects are in urgently need for new therapeutic strategies. This review article will concentrate on the most recent advancements of nanotechnologies, which facilitates chondrogenic and osteogenic differentiation for osteochondral regeneration. Moreover, this review will also discuss the current strategies and physiological challenges for the regeneration of osteochondral tissue. Specifically, we will summarize the latest developments of nanobased scaffolds for simultaneously regenerating subchondral bone and articular cartilage tissues. Additionally, perspectives of nanotechnology in osteochondral tissue engineering will be highlighted. This review article provides a comprehensive summary of the latest trends in cartilage and subchondral bone regeneration, paving the way for nanotechnologies in osteochondral tissue engineering. This article is categorized under: Implantable Materials and Surgical Technologies > Nanomaterials and Implants Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement.

Bovine serum albumin-templated nanoplatform for magnetic resonance imaging-guided chemodynamic therapy

BACKGROUND

Nanotechnology in medicine has greatly expanded the therapeutic strategy that may be explored for cancer treatment by exploiting the specific tumor microenvironment such as mild acidity, high glutathione (GSH) concentration and overproduced hydrogen peroxide (H2O2). Among them, tumor microenvironment responsive chemodynamic therapy (CDT) utilized the Fenton or Fenton-like reaction to produce excess hydroxyl radical (·OH) for the destruction of tumor cells. However, the produced ·OH is easily depleted by the excess GSH in tumors, which would undoubtedly impair the CDT's efficiency. To overcome this obstacle and enhance the treatment efficiency, we design the nanoplatforms for magnetic resonance imaging (MRI)-guided CDT.

RESULTS

In this study, we applied the bovine serum albumin (BSA)-templated CuS:Gd nanoparticles (CuS:Gd NPs) for MRI-guided CDT. The Cu2+ in the CuS:Gd NPs could be reduced to Cu+ by GSH in tumors, which further reacted with H2O2 and triggered Fenton-like reaction to simultaneously generate abundant ·OH and deplete GSH for tumor enhanced CDT. Besides, the Gd3+ in CuS:Gd NPs endowed them with excellent MRI capability, which could be used to locate the tumor site and monitor the therapy process preliminarily.

CONCLUSIONS

The designed nanoplatforms offer a major step forward in CDT for effective treatment of tumors guided by MRI.

Nanoparticle-Based Paramagnetic Contrast Agents for Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is a noninvasive medical imaging modality that is routinely used in clinics, providing anatomical information with micron resolution, soft tissue contrast, and deep penetration. Exogenous contrast agents increase image contrast by shortening longitudinal (T 1) and transversal (T 2) relaxation times. Most of the T 1 agents used in clinical MRI are based on paramagnetic lanthanide complexes (largely Gd-based). In moving to translatable formats of reduced toxicity, greater chemical stability, longer circulation times, higher contrast, more controlled functionalisation and additional imaging modalities, considerable effort has been applied to the development of nanoparticles bearing paramagnetic ions. This review summarises the most relevant examples in the synthesis and biomedical applications of paramagnetic nanoparticles as contrast agents for MRI and multimodal imaging. It includes the most recent developments in the field of production of agents with high relaxivities, which are key for effective contrast enhancement, exemplified through clinically relevant examples.

Green synthesis of gold nanoparticles using Euphrasia officinalisleaf extract to inhibit lipopolysaccharide-induced inflammation through NF-κB and JAK/STAT pathways in RAW 264.7 macrophages

Background

Gold nanoparticles (AuNPs) have potential applications in the treatment and diagnosis process, which are attributed to their biocompatibility and high efficiency of drug delivery. In the current study, we utilized an extract of Euphrasia officinalis, a traditional folk medicine, to synthesize gold nanoparticles (EO-AuNPs), and investigated their anti-inflammatory effects on lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages.

Materials and methods

The AuNPs were synthesized from an ethanol extract of E. officinalis leaves and characterized using several analytical techniques. Anti-inflammatory activities of EO-AuNPs were detected by a model of LPS-induced upregulation of inflammatory mediators and cytokines including nitric oxide (NO), inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α), IL-1β, and IL-6 in RAW 264.7 cells. The activation of nuclear factor (NF)-κB and Janus kinase/signal transducer and activators of transcription (JAK/STAT) signaling pathways was investigated by Western blot.

Results

The results confirmed the successful synthesis of AuNPs by E. officinalis. Transmission electron microscopy images showed obvious uptake of EO-AuNPs and internalization into intracellular membrane–bound compartments, resembling endosomes and lysosomes by RAW 264.7 cells. Cell viability assays showed that EO-AuNPs exhibited little cytotoxicity in RAW 264.7 cells at 100 µg/mL concentration after 24 hours. EO-AuNPs significantly suppressed the LPS-induced release of NO, TNF-α, IL-1β, and IL-6 as well as the expression of the iNOS gene and protein in RAW 264.7 cells. Further experiments demonstrated that pretreatment with EO-AuNPs significantly reduced the phosphorylation and degradation of inhibitor kappa B-alpha and inhibited the nuclear translocation of NF-κB p65. In addition, EO-AuNPs suppressed LPS-stimulated inflammation by blocking the activation of JAK/STAT pathway.

Conclusion

The synthesized EO-AuNPs showed anti-inflammatory activity in LPS-induced RAW 264.7 cells, suggesting they may be potential candidates for treating inflammatory-mediated diseases.

Biomimetic Mineralization of Magnetic Iron Oxide Nanoparticles Mediated by Bi-Functional Copolypeptides

Magnetite (Fe₃O₄) nanoparticles are widely used in multiple biomedical applications due to their magnetic properties depending on the size, shape and organization of the crystals. However, the crystal growth and morphology of Fe₃O₄ nanoparticles remain difficult to control without using organic solvent or a high temperature. Inspired by the natural biomineralization process, a 14-mer bi-functional copolypeptide, leveraging the affinity of binding Fe₃O₄ together with targeting ovarian cancer cell A2780, was used as a template in the biomimetic mineralization of magnetite. Alongside this, a ginger extract was applied as an antioxidant and a size-conditioning agent of Fe₃O₄ crystals. As a result of the cooperative effects of the peptide and the ginger extract, the size and dispersibility of Fe₃O₄ were controlled based on the interaction of the amino acid and the ginger extract. Our study also demonstrated that the obtained particles with superparamagnetism could selectively be taken up by A2780 cells. In summary, the Fe₃O₄-QY-G nanoparticles may have potential applications in targeting tumor therapy or angiography.

Gadolinium Metallofullerene-Based Activatable Contrast Agent for Tumor Signal Amplification and Monitoring of Drug Release

Activatable imaging probes are promising to achieve increased signal-to-noise ratio for accurate tumor diagnosis and treatment monitoring. Magnetic resonance imaging (MRI) is a noninvasive imaging technique with excellent anatomic spatial resolution and unlimited tissue penetration depth. However, most of the activatable MRI contrast agents suffer from metal ion-associated potential long-term toxicity, which may limit their bioapplications and clinical translation. Herein, an activatable MRI agent with efficient MRI performance and high safety is developed for drug (doxorubicin) loading and tumor signal amplification. The agent is based on pH-responsive polymer and gadolinium metallofullerene (GMF). This GMF-based contrast agent shows high relaxivity and low risk of gadolinium ion release. At physiological pH, both GMF and drug molecules are encapsulated into the hydrophobic core of nanoparticles formed by the pH-responsive polymer and shielded from the aqueous environment, resulting in relatively low longitudinal relativity and slow drug release. However, in acidic tumor microenvironment, the hydrophobic-to-hydrophilic conversion of the pH-responsive polymer leads to amplified MR signal and rapid drug release simultaneously. These results suggest that the prepared activatable MRI contrast agent holds great promise for tumor detection and monitoring of drug release.

A photo-inducible protein-inorganic nanoparticle assembly for active targeted tumour theranostics

The assembly of protein-inorganic nanoparticles is an important yet challenging approach that is utilized to develop functional materials in numerous areas, such as bio-catalysis, drug delivery, and biosensing. In this study, we report on a facile, photo-inducible self-assembly method to generate protein-inorganic hybrid nanoplatforms. More specifically, photo-treated disulfide bond rich proteins of lysozyme (LYS) were able to be used as host materials in order to encapsulate nanoparticles (i.e., as-synthesized hydrophobic NIR quantum dots (QDs)) and anti-cancer small molecule drugs (i.e., paclitaxel (PTX)), constructing functional theranostic protein-inorganic hybrid nanoparticles. The modification of the functional polymer of cRGD-PEG contributes to the active tumour targeting characteristic of this protein-inorganic nanocarrier. This novel PTX loaded protein-inorganic hybrid nanoplatform showed high tumour homing accumulation as well as effective tumour inhibition. We believe that this general approach represents a new direction for the development of a photo-induced assembly of protein-inorganic nanoparticles towards versatile applications in both materials science and biomedical fields.

Chlorotoxin peptide-functionalized polyethylenimine-entrapped gold nanoparticles for glioma SPECT/CT imaging and radionuclide therapy

BACKGROUND

Malignant glioma is the most common and deadliest brain cancer due to the obstacle from indistinct tumor margins for surgical excision and blood brain barrier (BBB) for chemotherapy. Here, we designed and prepared multifunctional polyethylenimine-entrapped gold nanoparticles (Au PENPs) for targeted SPECT/CT imaging and radionuclide therapy of glioma.

RESULTS

Polyethylenimine was selected as a template for sequential modification with polyethylene glycol (PEG), glioma-specific peptide (chlorotoxin, CTX) and 3-(4-hydroxyphenyl)propionic acid-OSu (HPAO), and were then used to entrap gold nanoparticles (Au NPs). After 131I radiolabeling via HPAO, the 131I-labeded CTX-functionalized Au PENPs as a multifunctional glioma-targeting nanoprobe were generated. Before 131I radiolabeling, the CTX-functionalized Au PENPs exhibited a uniform size distribution, favorable X-ray attenuation property, desired water solubility, and cytocompatibility in the given Au concentration range. The 131I-labeled CTX-functionalized Au PENPs showed high radiochemical purity and stability, and could be used as a nanoprobe for the targeted SPECT/CT imaging and radionuclide therapy of glioma cells in vitro and in vivo in a subcutaneous tumor model. Owing to the unique biological properties of CTX, the developed nanoprobe was able to cross the BBB and specifically target glioma cells in a rat intracranial glioma model.

CONCLUSIONS

Our results indicated that the formed nanosystem had the significant potential to be applied for glioma targeted diagnosis and therapy.

Ultrasmall hybrid protein–copper sulfide nanoparticles for targeted photoacoustic imaging of orthotopic hepatocellular carcinoma with a high signal-to-noise ratio

A schematic illustration of CuS@BSA-RGD nanoparticle synthesis and the application of photoacoustic imaging in an orthotopic HCC model.

Beyond the Roles in Biomimetic Chemistry: An Insight into the Intrinsic Catalytic Activity of an Enzyme for Tumor-Selective Phototheranostics

Protein-assisted biomimetic synthesis has been an emerging offshoot of nanofabrication in recent years owing to its features of green chemistry, facile process, and ease of multi-integration. As a result, many proteins have been used for biomimetic synthesis of varying kinds of nanostructures. Although the efforts on exploring new proteins and investigating their roles in biomimetic chemistry are increasing, the most essential intrinsic properties of proteins are largely neglected. Herein we report a frequently used enzyme (horseradish peroxidase, HRP) to demonstrate the possibility of enzymatic activity retaining after accomplishing the roles in biomimetic synthesis of ultrasmall gadolinium (Gd) nanodots and stowing its substrate 2,2'-Azinobis (3-ethylbenzothiazoline-6-sulfonic acid ammonium salt) (ABTS), denoted as Gd@HRP^ABTS. It was found that ca. 70% of the enzymatic activity of HRP was preserved. The associated changes of protein structure with chemical treatments were studied by spectroscopic analysis. Leveraging on the highly retained catalytic activity, Gd@HRP^ABTS exerts strong catalytic oxidation of peroxidase substrate ABTS into photoactive counterparts in the presence of intrinsic H₂O₂ inside the tumor, therefore enabling tumor-selective catalytic photoacoustic (PA) imaging and photothermal therapy (PTT). In addition, the MR moiety of Gd@HRP^ABTS provides guidance for PTT and further diagrams that Gd@HRP^ABTS is clearable from the body via kidneys. Preliminary toxicity studies show no observed adverse effects by administration of them. This study demonstrates beyond the well-known roles in biomimetic chemistry that HRP can also preserve its enzymatic activity for tumor catalytic theranostics.

Laser-Induced Transformable BiS@HSA/DTX Multiple Nanorods for Photoacoustic/Computed Tomography Dual-Modal Imaging Guided Photothermal/Chemo Combinatorial Anticancer Therapy

Suboptimal intratumor accumulation and poorly controllable release of encapsulated drugs remain unresolved challenges hampering further advancement of nanomedicines in cancer therapy. Herein, we conceived near-infrared (NIR) laser-triggered transformable BiS@HSA/DTX multiple nanorods (mNRs), which were made of small bundles of bismuth sulfide nanorods (BiS NRs) coated with docetaxel (DTX)-inlaid human serum albumin (HSA). The BiS@HSA/DTX mNRs had a lateral size of approximately 100 nm and efficiently accumulated in the tumor microenvironment upon systemic administration in tumor-bearing nude mice. NIR laser irradiation of the tumor area caused rapid disassembly of the BiS@HSA/DTX mNRs into individual HSA-coated BiS nanorods (BiS@HSA iNRs) and triggered the release of DTX from the HSA corona, due to the local temperature increase generated by BiS NRs via the photothermal effect. The laser-induced transformation into BiS@HSA iNRs facilitated their penetration and increased the retention time in tumor. The spatiotemporal delivery behavior of the BiS@HSA/DTX mNRs could be monitored by photoacoustic/computed tomography dual-modal imaging in vivo. Furthermore, because of the excellent photothermal conversion properties of BiS NRs and laser-triggered DTX release from BiS@HSA/DTX mNRs, efficient tumor combinatorial therapy was achieved via concurrent hyperthermia and chemotherapy in mice treated with BiS@HSA/DTX mNRs upon NIR laser irradiation.

Sequence-Specific Control of Inorganic Nanomaterials Morphologies by Biomolecules

Controlling morphologies of nanomaterials such as their shapes and surface features has been a major endeavor in the field of nanoscale science and engineering, because the morphology is a major determining factor for functional properties of nanomaterials. Compared with conventional capping ligands based on organic molecules or polymers, the programmability of biomolecules makes them attractive alternatives for morphology-controlled nanomaterials synthesis. Towards the goal of predictable control of the synthesis, many studies have been performed on using different sequences of biomolecules to generate specific nanomaterial morphology. In this review, we summarize recent studies in the past few years on using DNA and peptide sequences to control inorganic nanomaterial morphologies, focusing on both case studies and mechanistic investigations. The functional properties resulting from such a sequence-specific control are also discussed, along with strengths and limitations of different approaches to achieving the goal.

Ultra-small Albumin Templated Gd/Ru Composite Nanodots for In Vivo Dual modal MR/Thermal Imaging Guided Photothermal Therapy

Multifunctional theranostic nanoagents which realize precise diagnosis and treatment of tumors are attracting increasing interests in recent years. However, efficient and controlled synthesis of ultra-small noble metal nanoagents remains a challenge. Here, monodisperse Gd/Ru@BSA nanodots (GRBNDs) are successfully fabricated via a totally "green", "one-pot" protocol for in situ reduction of Ru(III) and biomineralization of Gd(III) in the presence of albumin. The as-prepared nanoagent possesses the features of being ultra small in size (≈6.7 nm), having strong colloidal stability, and thermal stability as well as high photothermal conversion efficiency (η = 50.7%). As expected, the GRBNDs achieve a significant efficacy of anticancer therapy under LASER activation both in vitro and in vivo. It also exhibits superior T₁ -weighted magnetic resonance (MR) imaging ability due to its high longitudinal relaxivity value (r₁ = 10.98 × 10^-3 m^-1 s^-1 ). Moreover, it is demonstrated to be renal clearable with negligible systemic toxicity. This work highlights a straightforward and repeatable approach for synthesizing highly effective and multifunctional noble metal nanoagent of great clinical promising for cancer theranostics.

Plant-based metallic nanoparticles as potential theranostics agents: bioinspired tool for imaging and treatment

Theranostic approach provides us a platform where diagnosis and treatment can be carried out simultaneously. Biosynthesis of theranostic-capable nanoparticles (NPs) can be carried out by phytoconstituents present inside the plants that can act as capping as well as stabilising agents by offering several advantages over chemical and physical methods. This article highlights the theranostic role of NPs with emphasis on potential of plants to produce these NPs through ecofriendly approach that is called 'Green synthesis'. Biosynthesis, advantages, and disadvantages of plant-based theronostics have been discussed for better understanding. Moreover, this article has highlighted the approaches required to optimise the plant-mediated synthesis of NPs and to avoid the toxicity of these agents. Anticipating all of the challenges, the authors expect biogenic NPs can appear as potential diagnostic and therapeutic agents in near future.

Self-assembly synthesis of vapreotide‑gold hybrid nanoflower for photothermal antitumor activity

Based on the self-assembly properties of vapreotide acetate (Vap), one kind of novel vapreotide acetate‑gold nanoflowers (Vap-AuNFs) was fabricated for the first time by biomimetic mineralization method using Vap as a template. The Vap-AuNFs possessed anisotropic structure with a large absorption cross-section, which were face-centered cubic crystalline, exhibiting a remarkable monodisperse, narrow size (154 nm) distribution and good stability in aqueous solution. The apparent anisotropy of the gold nanostructure with high molar extinction coefficient can cause significantly higher plasmon absorption of Vap-AuNFs in the near infrared (NIR) region compared with Au nanoparticles (AuNPs), so the nanocomplex can induce remarkably enhanced photothermal conversion efficiency under NIR light irradiation. Breathtakingly, Vap-AuNFs exhibited superior biocompatibilities compared to AuNPs, as well as enhanced Hela cells lethality under NIR irradiation. This novel method was simple, low cost and green for the design and preparation of anisotropic gold nanoflowers with outstanding NIR laser-induced local hyperthermia, highlighting their potential applications in biomedical fields.