One-step facile synthesis of hyaluronic acid functionalized fluorescent gold nanoprobes sensitive to hyaluronidase in urine specimen from bladder cancer patients

Electrochemiluminescence Biosensor for Hyaluronidase Based on the Adjustable Electrostatic Interaction between the Surface-Charge-Controllable Nanoparticles and Negatively Charged Electrode

A novel electrochemiluminescence (ECL) biosensor for hyaluronidase (HAase) based on the adjustable electrostatic interaction between the surface-charge-controllable nanoparticles and negatively charged electrode has been devised. Hyaluronic acid (HA)-coated amino-modified ruthenium bipyridine-doped silica nanoparticles (Ru@SiO₂-NH₂@HA NPs) have been synthesized and act as ECL indicators, and the surface of this particle is negatively charged because HA contains a large amount of OH- and COO-. The strong electrostatic repulsion between the Ru@SiO₂-NH₂@HA NPs and negatively charged indium tin oxide (ITO) electrode surface leads to the detection of a low-intensity ECL signal. In the presence of HAase, the HA on the surface of the Ru@SiO₂-NH₂@HA NPs can be decomposed, and the particles can be transformed into positively charged amino-modified ruthenium bipyridine-doped silica nanoparticles (Ru@SiO₂-NH₂ NPs), which can be concentrated near the surface of the ITO electrode through electrostatic attraction, and result in the detection of an enhanced ECL signal. The ECL of the system has a good linear relationship with HAase concentration in the range of 2.0-60 U/mL, and the limit of detection was 0.37 U/mL. The designed biosensor had been applied to detect the target in real samples with satisfied results.

Paper-Based Flow Sensor for the Detection of Hyaluronidase via an Enzyme Hydrolysis-Induced Viscosity Change in a Polymer Solution

Hyaluronidase (HAase) is implicated in inflammation, cancer development, and allergic reaction. The detection of HAase is significantly important in clinical diagnosis and medical treatment. Herein, we propose a new principle for the development of equipment-free and label-free paper-based flow sensors based on the enzymatic hydrolysis-induced viscosity change in a stimuli-responsive polymer solution, which increases the water flow distance on the pH indicator paper. The detection of HAase is demonstrated as an example. This facile and versatile method can overcome the potential drawbacks of traditional hydrogel-based sensors, including complex preparation steps, slow response time, or low sensitivity. Moreover, it can also avoid the use of specialized instruments, labeled molecules, or functionalized nanoparticles in the sensors developed using the polymer solutions. Using this strategy, the detection of HAase is achieved with a limit of detection as low as 0.2 U/mL. Also, it works well in human urine. Additionally, the detection of tannic acid, which is an inhibitor of HAase, is also fulfilled. Overall, a simple, efficient, high-throughput, and low-cost detection method is developed for the rapid and quantitative detection of HAase and its inhibitor without the use of labeled molecules, synthetic particles, and specialized instruments. As only minimal reagents of HAase, HA, and paper are used, it is very promising in the development of commercial kits for point-of-care testing.

Nanogold-based materials in medicine: from their origins to their future

The properties of gold-based materials have been explored for centuries in several research fields, including medicine. Multiple published production methods for gold nanoparticles (AuNPs) have shown that the physicochemical and optical properties of AuNPs depend on the production method used. These different AuNP properties have allowed exploration of their usefulness in countless distinct biomedical applications over the last few years. Here we present an extensive overview of the most commonly used AuNP production methods, the resulting distinct properties of the AuNPs and the potential application of these AuNPs in diagnostic and therapeutic approaches in biomedicine.

Convenient hyaluronidase biosensors based on the target-trigger enhancing of the permeability of a membrane using an electronic balance as a readout

The change in hyaluronidase (HAase) is related to specific changes in the structure of vitreous, and it is necessary to develop simple but sensitive methods for HAase detection. In this work, a thin film fabricated from a hyaluronic acid (HA)-polyethyleneimine (PEI) hydrogel has been covered on a mixed cellulose microporous membrane (MCEM) to form a HA-PEI-MCEM firstly and it was then applied in a filtration system. The permeability of the filter membrane greatly affects the amount of water passing through within a certain time and the water can be collected and quantitatively measured with a simple electronic balance easily. The low permeability of the HA-PEI-MCEM allows a small amount of water to be drained. But after the addition of HAase, which can hydrolyze HA in the hydrogel, the permeability of the membrane increased. Therefore, the amount of water passing through the HA-PEI-MCEM composite membrane increased accordingly. The composite of the membrane, and the reaction conditions after the addition of HAase were optimized. Under the optimized conditions, the amount of water collected within 5 min showed a linear relationship with the HAase concentration in a range of 1.0-36 U mL-1 with a limit of detection of 0.35 U mL-1.The proposed method has been applied to detect HAase in vitreous samples with satisfactory results.

Rational design of a HA-AuNPs@AIED nanoassembly for activatable fluorescence detection of HAase and imaging in tumor cells

Aggregation induced emission (AIE) dots have gained broad attention in fluorescence bioimaging and biosensors in virtue of their distinctive optical properties of splendid biocompatibility, high brightness and good photostability. However, the application of AIE dots in sensing and imaging of enzymes in cells remains at an early stage and needs to be further explored. In this report, we proposed a novel AIE-dot-based nanoprobe for hyaluronidase (HAase) detection using a simple electrostatic self-assembly of AIE dots with gold nanoparticles functionalized using hyaluronic acid (HA-AuNPs), named HA-AuNPs@AIEDs. The fluorescence of AIE dots can be obviously quenched by HA-AuNPs via fluorescence resonance energy transfer (FRET). HAase could degrade HA into small pieces and thus induce disassembly of AuNPs and AIEDs, accompanied by fluorescence recovery of AIEDs. The as-prepared nanoprobe exhibited high sensitivity, excellent selectivity, wide response range and desirable anti-interference for quantitative sensing of HAase in vitro. The detection limit was down to 0.0072 U mL^-1. Moreover, the nanoprobe displayed good biocompatibility and excellent photostability, and thus offered a practicable "turn-on" strategy for specific, high-contrast fluorescence imaging of HAase in live tumor cells. The AIE-based nanoprobe may provide a novel universal platform for recognition and imaging of HAase in tumors, and may be beneficial for related biological research.

One-pot synthesis of hyaluronic acid-coated gold nanoparticles as SERS substrate for the determination of hyaluronidase activity

A novel ultrasensitive surface-enhanced Raman spectroscopy (SERS)-based method was developed for the determination of hyaluronidase (HAase), which was based on hyaluronic acid-coated gold nanoparticles (HA-AuNPs) as a substrate, via a facile one-pot method. The detection mechanism is based on HAase which can hydrolyze HA on HA-AuNPs into hyaluronic acid oligomers, causing the originally uniformly dispersed HA-AuNPs to be disintegrated into many smaller HA-AuNPs. These oligomers in turn increase the surface shielding of AuNPs, resulting in high aggregation tendencies. As a result, the original SERS substrate was disassembled, leading to a weakening of the SERS signal at 1173 cm^-1. Malachite green was also used as a Raman probe to detect the change of SERS peak intensity and to quantify HAase. Compared with other methods for the determination of HAase, this method is more convenient and efficient; its determination limit was 0.4 mU mL^-1. The recoveries of HAase spiked into human urine samples ranged from 97.2 to 103.9%.

A Review of Biodegradable Natural Polymer-Based Nanoparticles for Drug Delivery Applications

Biodegradable natural polymers have been investigated extensively as the best choice for encapsulation and delivery of drugs. The research has attracted remarkable attention in the pharmaceutical industry. The shortcomings of conventional dosage systems, along with modified and targeted drug delivery methods, are addressed by using polymers with improved bioavailability, biocompatibility, and lower toxicity. Therefore, nanomedicines are now considered to be an innovative type of medication. This review critically examines the use of natural biodegradable polymers and their drug delivery systems for local or targeted and controlled/sustained drug release against fatal diseases.

Recent advantage of hyaluronic acid for anti-cancer application: a review of "3S" transition approach

In recent years, nano drug delivery system has been widely concerned because of its good therapeutic effect. However, the process from blood circulation to cancer cell release of nanodrugs will be eliminated by the human body's own defense trap, thus reducing the therapeutic effect. In recent years, a "3S" transition concept, including stability transition, surface transition and size transition, was proposed to overcome the barriers in delivery process. Hyaluronic (HA) acid has been widely used in delivery of anticancer drugs due to its excellent biocompatibility, biodegradability and specific targeting to cancer cells. In this paper, the strategies and methods of HA-based nanomaterials using "3S" theory are reviewed. The applications and effects of "3S" modified nanomaterials in various fields are also introduced.

A novel surface-enhanced Raman scattering-based ratiometric approach for detection of hyaluronidase in urine

A ratiometric surface-enhanced Raman scattering (SERS) based method is described for the determination of the activity of hyaluronidase (HAase). Gold nanorods (AuNRs) were functionalized with 4-thiobenzonitrile (TBN) to act as the Raman reporter (TBN-AuNRs), and 4-thiophenylacetylene-functionalized gold-silver alloy nanoparticles (TPA-AuAgNPs) were used as the reference. Hyaluronic acid (HA) acts as the HAase recognition element. The TBN-modified AuNRs aggregate in the presence of HA due to the strong electrostatic interaction between the positively charged TBN-AuNRs and negatively charged HA. This strongly enhances the Raman signal of TBN at 2220 cm^-1. However, HA has no significant effect on the dispersion of the modified AuAg NPs which are electroneutral. Hence, no change can be seen in the Raman intensity of TPA at 1974 cm^-1. In the presence of HAase, HA is digested into smaller fragments. This results in good dispersion of the TBN-AuNRs and a weaker TBN Raman signal. Hence, the ratio of the Raman peaks at 1974 and 2220 cm^-1 increases. Under the optimized conditions, the ratio changes in the 5-70 U mL^-1 HAase activity range, and the detection limit is 1.7 U mL^-1 (based on the 3σ rule). Moreover, this method has been successfully applied in the determination of the activity of HAase in artificial urine and it is expected to be a new method for the diagnosis of cancer, especially bladder cancer.

Electrochemiluminescence Biosensor for Hyaluronidase Based on the Ru(bpy)32+ Doped SiO2 Nanoparticles Embedded in the Hydrogel Fabricated by Hyaluronic Acid and Polyethylenimine

Hyaluronidase (HAase), a specific enzyme of hyaluronic acid (HA), has been reported as a potential tumor biomarker in recent years. Hence, developing some simple, rapid, and sensitive methods for HAase assay is necessary. In this work, a simple and sensitive biosensor constructed by a reliable controlled release system and a mature electrochemiluminescence (ECL) analytical technique has been devised for the quantification of HAase with high efficiency and selectivity. Tris (2,2'-bipyridyl) ruthenium(II) chloride hexahydrate doped SiO₂ nanoparticles (Ru@SiO₂ NPs), as ECL signal probes, were trapped in the hydrogel fabricated by HA and polyethylenimine evenly and steadily. When HAase existed, the hydrogel was decomposed by HAase, and the Ru@SiO₂ NPs escaped from the hydrogel into the supernate. The ECL signal produced from the supernate can be detected and used to characterize HAase concentration. The result showed a good linear relationship between ECL intensity, and HAase concentration ranged from 2 to 60 U/mL and the limit of detection was 2 U/mL. The developed controlled release ECL biosensor has been used for HAase quantification in urine samples with satisfactory results.

Investigation of the surface confinement effect of copper nanoclusters: construction of an ultrasensitive fluorescence turn-on bio-enzyme sensing platform

Copper nanoclusters (CuNCs) have attracted considerable research interest due to their good physicochemical properties, ease of preparation, and low price. However, the low quantum yield and poor stability in aqueous solutions have greatly limited their applications. In order to improve the fluorescence properties and stability of CuNCs, in this paper, the surface confinement effect of CuNCs based on 2D layered double hydroxide (LDH) was proposed to prepare the fluorescent composites of glutathione protected CuNCs and LDH (GS-CuNCs/LDH) with excellent quantum yield and long fluorescence lifetime. Moreover, a novel, simple, and ultrasensitive fluorescence assay for the detection of hyaluronidase was proposed based on the surface confinement effect. The limit of detection for hyaluronidase was as low as 0.014 U mL-1. For the first time, this work developed a bio-enzyme sensing platform based on the surface confinement effect, which can serve as a promising candidate in biosensing.

Hyaluronic Acid-Based Activatable Nanomaterials for Stimuli-Responsive Imaging and Therapeutics: Beyond CD44-Mediated Drug Delivery

There is a rapidly increasing interest in developing stimuli-responsive nanomaterials for treating a variety of diseases. By enabling the activation of function locally at the sites of interest, it is possible to increase therapeutic efficacy significantly while simultaneously reducing adverse side effects. While there are many sophisticated nanomaterials available, they are often highly complex and not easily transferrable to industrial scales and clinical settings. However, nanomaterials based on hyaluronic acid offer a compelling strategy for reducing their complexity while retaining several desirable benefits such as active targeting and stimuli-responsive degradation. Herein, the basic properties of hyaluronic acid, its binding partners, and natural routes for degradation by hyaluronidases-hyaluronic-acid-degrading enzymes-and oxidative stresses are discussed. Recent advances in designing hyaluronic acid-based, actively targeted, hyaluronidase- or reactive-oxygen-species-responsive nanomaterials for both diagnostic imaging and therapeutic delivery, which go beyond merely the classical targeting of CD44, are summarized.

Analyzing Hyaluronidases in Biological Fluids

Hyaluronidases are a group of enzymes responsible for the degradation of hyaluronan. They seem to be associated with a plethora of pathological conditions, as it has been showcased by numerous studies over the past years. The emerging role of hyaluronidases in various pathological states, especially cancer, is of a great interest. Thus, they are considered as important research targets.In this chapter the popular assay for hyaluronidase analysis in biological fluids is presented and discussed in detail. The assay is divided into two steps; the first is zymography that aims mainly to detect different hyaluronidase enzymes in a biological sample, and the second is the direct quantitative measurement of enzymatic activity by a microtiter plate assay. Both steps are characterized by high sensitivity, simplicity, and limited time consumption.

Selective and sensitive detection of lysozyme based on plasmon resonance light-scattering of hydrolyzed peptidoglycan stabilized-gold nanoparticles

The simple, economic, rapid, and sensitive detection of lysozyme has an important significance for disease diagnosis since it is a potential biomarker. In this work, a new detection strategy for lysozyme was developed based on the change of the plasmon resonance light scattering (PRLS) signal of peptidoglycan stabilized gold nanoparticles (PGN-AuNPs). Peptidoglycan (PGN) was employed as a stabilizer to prepare PGN-AuNPs which have the properties of a uniform particle size, good stability, and a specific biological function. Due to the specific cleavage of lysozyme to PGN, a very simple specific and sensitive detection method for lysozyme was developed based on the PRLS signal of PGN-AuNPs after mixing with lysozyme for 1.5 h. The enhanced PRLS signals (ΔI_PRLS, at 560 nm) increased linearly with increasing lysozyme in the range 5 nM to 1600 nM with the detection limit down to 2.32 nM (ΔI_PRLS = 41.6397 + 0.5332c, R = 0.9961). When the PGN-AuNP based method was applied to assay lysozyme in authentic human serum samples, the recovery efficiency was 106.76-119.32% with the relative standard deviations in the range of 0.14-3.11%, showing good feasibility. The PGN-AuNP based method for lysozyme assay developed here is simple, rapid, selective, and sensitive, which is expected to provide a feasible new method for the diagnosis or prognosis of lysozyme-related diseases in a clinical setting.

A label-free and fluorescence turn-on assay for sensitive detection of hyaluronidase based on hyaluronan-induced perylene self-assembly

A label-free and fluorescence turn-on assay for sensitive detection of HAase based on HA–PDI nanoaggregates was reported.

Potential Applications of Nanotechnology in Urological Cancer

Nowadays, the potential scope of nanotechnology in uro-oncology (cancers of the prostate, bladder, and kidney) is broad, ranging from drug delivery, prevention, and diagnosis to treatment. Novel drug delivery methods using magnetic nanoparticles, gold nanoparticles, and polymeric nanoparticles have been investigated in prostate cancer. Additionally, renal cancer treatment may be profoundly influenced by applications of nanotechnology principles. Various nanoparticle-based strategies for kidney cancer therapy have been proposed. Partly due to the dilution of drug concentrations by urine production, causing inadequate drug delivery to tumor cells in the treatment of bladder cancer, various multifunctional bladder-targeted nanoparticles have been developed to enhance therapeutic efficiency. In each of these cancer research fields, nanotechnology has shown several advantages over widely used traditional methods. Different types of nanoparticles improve the solubility of poorly soluble drugs, and multifunctional nanoparticles have good specificity toward prostate, renal, and bladder cancer. Moreover, nanotechnology can also combine with other novel technologies to further enhance effectivity. As our understanding of nanotechnologies grows, additional opportunities to improve the diagnosis and treatment of urological cancer are excepted to arise. In this review, we focus on nanotechnologies with potential applications in urological cancer therapy and highlight clinical areas that would benefit from nanoparticle therapy.

Hyaluronan-Inorganic Nanohybrid Materials for Biomedical Applications

Nanomaterials, including gold, silver, and magnetic nanoparticles, carbon, and mesoporous materials, possess unique physiochemical and biological properties, thus offering promising applications in biomedicine, such as in drug delivery, biosensing, molecular imaging, and therapy. Recent advances in nanotechnology have improved the features and properties of nanomaterials. However, these nanomaterials are potentially cytotoxic and demonstrate a lack of cell-specific function. Thus, they have been functionalized with various polymers, especially polysaccharides, to reduce toxicity and improve biocompatibility and stability under physiological conditions. In particular, nanomaterials have been widely functionalized with hyaluronan (HA) to enhance their distribution in specific cells and tissues. This review highlights the most recent advances on HA-functionalized nanomaterials for biotechnological and biomedical applications, as nanocarriers in drug delivery, contrast agents in molecular imaging, and diagnostic agents in cancer therapy. A critical evaluation of barriers affecting the use of HA-functionalized nanomaterials is also discussed, and insights into the outlook of the field are explored.

Fluorescence lifetime imaging with time-gated detection of hyaluronidase using a long lifetime azadioxatriangulenium (ADOTA) fluorophore

A fluorescence lifetime imaging probe with a long lifetime was used in combination with time-gating for the detection of hyaluronidase using hyaluronic acid as the probe template. This probe was developed by heavily labeling hyaluronic acid with long lifetime azadioxatriangulenium fluorophores (ADOTA). We used this probe to image hyaluronidase produced by DU-145 prostate cancer cells.

One-Step Synthesis of Water-Soluble MoS2 Quantum Dots via a Hydrothermal Method as a Fluorescent Probe for Hyaluronidase Detection

In this work, a bottom-up strategy is developed to synthesize water-soluble molybdenum disulfide quantum dots (MoS2 QDs) through a simple, one-step hydrothermal method using ammonium tetrathiomolybdate [(NH4)2MoS4] as the precursor and hydrazine hydrate as the reducing agent. The as-synthesized MoS2 QDs are few-layered with a narrow size distribution, and the average diameter is about 2.8 nm. The resultant QDs show excitation-dependent blue fluorescence due to the polydispersity of the QDs. Moreover, the fluorescence can be quenched by hyaluronic acid (HA)-functionalized gold nanoparticles through a photoinduced electron-transfer mechanism. Hyaluronidase (HAase), an endoglucosidase, can cleave HA into proangiogenic fragments and lead to the aggregation of gold nanoparticles. As a result, the electron transfer is blocked and fluorescence is recovered. On the basis of this principle, a novel fluorescence sensor for HAase is developed with a linear range from 1 to 50 U/mL and a detection limit of 0.7 U/mL.

Dual Recognition Strategy for Specific and Sensitive Detection of Bacteria Using Aptamer-Coated Magnetic Beads and Antibiotic-Capped Gold Nanoclusters

Food poisoning and infectious diseases caused by pathogenic bacteria such as Staphylococcus aureus (SA) are serious public health concerns. A method of specific, sensitive, and rapid detection of such bacteria is essential and important. This study presents a strategy that combines aptamer and antibiotic-based dual recognition units with magnetic enrichment and fluorescent detection to achieve specific and sensitive quantification of SA in authentic specimens and in the presence of much higher concentrations of other bacteria. Aptamer-coated magnetic beads (Apt-MB) were employed for specific capture of SA. Vancomycin-stabilized fluorescent gold nanoclusters (AuNCs@Van) were prepared by a simple one-step process and used for sensitive quantification of SA in the range of 32-10(8) cfu/mL with the detection limit of 16 cfu/mL via a fluorescence intensity measurement. And using this strategy, about 70 cfu/mL of SA in complex samples (containing 3 × 10(8) cfu/mL of other different contaminated bacteria) could be successfully detected. In comparison to prior studies, the developed strategy here not only simplifies the preparation procedure of the fluorescent probes (AuNCs@Van) to a great extent but also could sensitively quantify SA in the presence of much higher concentrations of other bacteria directly with good accuracy. Moreover, the aptamer and antibiotic used in this strategy are much less expensive and widely available compared to common-used antibodies, making it cost-effective. This general aptamer- and antibiotic-based dual recognition strategy, combined with magnetic enrichment and fluorescent detection of trace bacteria, shows great potential application in monitoring bacterial food contamination and infectious diseases.

Cationic Conjugated Polymer/Hyaluronan-Doxorubicin Complex for Sensitive Fluorescence Detection of Hyaluronidase and Tumor-Targeting Drug Delivery and Imaging

Hyaluronidase (HAase) is becoming a new type of tumor marker since it has been demonstrated to be overexpressed in various kinds of cancer cells. In this study, we described a novel fluorescence method for sensitive, rapid, and convenient HAase detection and tumor-targeting drug delivery and imaging, using a probe prepared by electrostatic assembly of a cationic conjugated polymer (CCP) and anionic hyaluronan (HA) conjugated with the anticancer drug doxorubicin (Dox). The CCP we used was poly{[9,9-bis(6'-(N,N,N-diethylmethylammonium)hexyl)-2,7-fluorenylene ethynylene]-alt-co-[2,5-bis(3'-(N,N,N-diethylmethylammonium)-1'-oxapropyl)-1,4-phenylene]} tetraiodide (PFEP). HA is a natural mucopolysaccharide that can be hydrolyzed by HAase into fragments with low molecular weights. In the PFEP/HA-Dox complex, the fluorescence of PFEP was efficiently quenched due to electron transfer from PFEP to Dox. After the PFEP/HA-Dox complex was exposed to HAase or was taken up by cancer cells through the specific binding between HA and CD44 receptor, HA was degraded by HAase to release the Dox, leading to the recovery of PFEP fluorescence to the "turn-on" state. Moreover, the degree of fluorescence recovery was quantitatively correlated with the concentrations of HAase. Compared with many previously reported methods, our work did not require laborious multiple modifications of HA that may affect the activity of HAase. This point, combined with the excellent optoelectronic property of conjugated polymer, endowed this method with high sensitivity (detection limit: 0.075 U/mL), high specificity, and rapid response, making it applicable for reliable and routine detection of HAase. This fluorescent probe was successfully utilized to detect HAase levels in human urine samples; furthermore, it can also be employed as a multifunctional system by realizing tumor-targeting drug delivery and cell imaging simultaneously. The development of this fluorescence method showed promising potential for early tumor diagnosis and therapy based on HAase detection.

Review: Application of Nanoparticles in Urothelial Cancer of the Urinary Bladder

Bladder cancer is a common malignancy of the urinary tract, which generally develops in the epithelial lining of the urinary bladder. The specific course of treatment depends on the stage of bladder cancer; however, therapeutic strategies typically involve intravesical drug delivery to reduce toxicity and increase therapeutic effects. Recently, metallic, polymeric, lipid, and protein nanoparticles have been introduced to aid in the treatment of bladder cancer. Nanoparticles are also commonly used as pharmaceutical carriers to improve interactions between drugs and the urothelium. In this review, we classify the characteristics of bladder cancer and discuss the types of nanoparticles used in various treatment modalities. Finally we summarize the potential applications and benefits of various nanoparticles in intravesical therapy.

Amino-functionalized green fluorescent carbon dots as surface energy transfer biosensors for hyaluronidase

Amino-functionalized fluorescent carbon dots have been prepared by hydrothermal treatment of glucosamine with excess pyrophosphate. The produced carbon dots showed stabilized green emission fluorescence at various excitation wavelengths and pH environments. Herein, we demonstrate the surface energy transfer between the amino-functionalized carbon dots and negatively charged hyaluronate stabilized gold nanoparticles. Hyaluronidase can degrade hyaluronate and break down the hyaluronate stabilized gold nanoparticles to inhibit the surface energy transfer. The developed fluorescent carbon dot/gold nanoparticle system can be utilized as a biosensor for sensitive and selective detection of hyaluronidase by two modes which include fluorescence measurements and colorimetric analysis.