Microfluidic-assisted preparation of PLGA nanoparticles loaded with insulin: a comparison with double emulsion solvent evaporation method.

Poly lactic-co-glycolic acid (PLGA) is an ideal polymer for the delivery of small and macromolecule drugs. Conventional preparation methods of PLGA nanoparticles (NPs) result in poor control over NPs properties. In this research, a microfluidic mixer was designed to produce insulin-loaded PLGA NPs with tuned properties. Importantly; aggregation of the NPs through the mixer was diminished due to the coaxial mixing of the precursors. The micromixer allowed for the production of NPs with small size and narrow size distribution compared to the double emulsion solvent evaporation (DESE) method. Furthermore, encapsulation efficiency and loading capacity indicated a significant increase in optimized NPs produced through the microfluidic method in comparison to DESE method. NPs prepared by the microfluidic method were able to achieve a more reduction of trans-epithelial electrical resistance values in the Caco-2 cells compared to those developed by the DESE technique that leads to greater paracellular permeation. Compatibility and interaction between components were evaluated by differential scanning calorimetry and fourier transform infrared analysis. Also, the effect of NPs on cell toxicity was investigated using MTT test. Numerical simulations were conducted to analyze the effect of mixing patterns on the properties of the NPs. It was revealed that by decreasing flow rate ratio, i.e. flow rate of the organic phase to the flow rate of the aqueous phase, mixing of the two streams increases. As an alternative to the DESE method, high flexibility in modulating hydrodynamic conditions of the microfluidic mixer allowed for nanoassembly of NPs with superior insulin encapsulation at smaller particle sizes.

Optimization of cobalt ferrite magnetic nanoparticle as a theranostic agent: MRI and hyperthermia.

OBJECTIVE: Magnetic nanoparticles (MNPs) are considered a theranostic agent in MR imaging, playing an effective role in inducing magnetic hyperthermia. Since, high-performance magnetic theranostic agents are characterized by superparamagnetic behavior and high anisotropy, in this study, cobalt ferrite MNPs were optimized and investigated as a theranostic agent. METHODS: CoFe2O4@Au@dextran particles were synthesized and characterized by DLS, HRTEM, SEM, XRD, FTIR, and VSM methods. After cytotoxicity evaluation, MR imaging parameters (r1, r2 and r2 / r1) were calculated for these nanostructures. Afterward, magnetic hyperthermia at the frequency of 425 kHz was applied to calculate specific loss power (SLP). RESULTS: Formation of CoFe2O4@Au@dextran was confirmed by UV-Visible spectrophotometry. On the basis of the relaxometric and hyperthermia induction findings of nanostructures in all stages of synthesis, the CoFe2O4@Au@dextran could produce the highest parameters of r2 and r2/r1 and SLP with values ​​of 389.7, 51.2 mM-1 s-1, and 2449 W/g, respectively. CONCLUSION: The formation of multi-core MNPs by dextran coating is expected to improve the magnetic properties of the nanostructure, leading to optimization of theranostic parameters, so that CoFe2O4@Au@dextran NPs can create contrast-enhanced images more than three times the clinical use and require less contrast agent, reducing side effects. Accordingly, CoFe2O4@Au@dextran can be introduced as a suitable theranostic nanostructure with optimal efficiency.

Signal amplification strategies in biosensing of extracellular vesicles (EVs).

Extracellular vesicles (EVs) are membrane-enclosed vesicles secreted from mammalian cells. EVs act as multicomponent delivery vehicles to carry a wide variety of biological molecular information and participate in intercellular communications. Since elevated levels of EVs are associated with some pathological states such as inflammatory diseases and cancers, probing circulating EVs holds a great potential for early diagnostics. To this end, several detection methods have been developed in which biosensors have attracted great attentions in identification of EVs due to their simple instrumentation, versatile design and portability for point-of-care applications. The concentrations of EVs in bodily fluids are extremely low (i.e. 1-100 per µl) at early stages of a disease, which necessitates the use of signal amplification strategies for EVs detection. In this way, this review presents and discusses various amplification strategies for EVs biosensors based on detection modalities including surface plasmon resonance (SPR), calorimetry, fluorescence, electrochemical and electrochemiluminescence (ECL). In addition, microfluidic systems employed for signal amplification are reviewed and discussed in terms of their design and integration with the detection methods.

A microfluidic electrochemical aptasensor for highly sensitive and selective detection of A549 cells as integrin α6ß4-containing cell model via IDA aptamers.

There is a growing interest in developing microfluidic biosensors for the accurate and reproducible analysis of various biomarkers obtained from liquid biopsy. This paper reports a novel microfluidic electrochemical aptasensor for determination of A549 cells as integrin α6ß4-containing cell model and circulating tumor cell (CTC) model of NSCLC, based on target-induced structure switching mode. The conformational change of IDA aptamer structure with an affinity towards A549 cells, in the absence and presence of A549 cells allowed selective and sensitive detection of A549 cells. The microfluidic biosensor consisted of a microchip integrated with a screen-printed gold electrode functionalized with SH-IDA aptamers via covalent chemistry. Target solution containing A549 cells in Phosphate-buffered saline could be introduced to the microchip for analysis. Upon exposing to redox probe, a reduction in peak current occurred. Required flow sequencing for various steps of the detection protocol was performed using on-chip gas-actuated microvalves with programmable operation. The microfluidic biosensor provided a wide linear dynamic range of 50-5 × 105 cells/mL and allowed determination of A549 cells with a detection limit of 14 cells/mL. Furthermore, the microfluidic biosensor was efficiently used for detection of A549 cells in complex matrices such as human serum. Our novel microfluidic aptasensor presents an enabling analytical platform to perform various detections of low volume biomarkers with high accuracy and reproducibility.

Additively manufactured porous scaffolds by design for treatment of bone defects.

There has been increasing attention to produce porous scaffolds that mimic human bone properties for enhancement of tissue ingrowth, regeneration, and integration. Additive manufacturing (AM) technologies, i.e., three dimensional (3D) printing, have played a substantial role in engineering porous scaffolds for clinical applications owing to their high level of design and fabrication flexibility. To this end, this review article attempts to provide a detailed overview on the main design considerations of porous scaffolds such as permeability, adhesion, vascularisation, and interfacial features and their interplay to affect bone regeneration and osseointegration. Physiology of bone regeneration was initially explained that was followed by analysing the impacts of porosity, pore size, permeability and surface chemistry of porous scaffolds on bone regeneration in defects. Importantly, major 3D printing methods employed for fabrication of porous bone substitutes were also discussed. Advancements of MA technologies have allowed for the production of bone scaffolds with complex geometries in polymers, composites and metals with well-tailored architectural, mechanical, and mass transport features. In this way, a particular attention was devoted to reviewing 3D printed scaffolds with triply periodic minimal surface (TPMS) geometries that mimic the hierarchical structure of human bones. In overall, this review enlighten a design pathway to produce patient-specific 3D-printed bone substitutions with high regeneration and osseointegration capacity for repairing large bone defects.

Effects of Portulaca oleracea L. (purslane) on the metabolic syndrome: A review.

Metabolic syndrome (MetS) is defined as a disorder with multiple abnormalities, including obesity, high blood pressure, dyslipidemia, and high blood glucose. MetS is the best-known risk factor for type 2 diabetes mellitus (T2DM), cardiovascular disease (CVD), and obesity. With the globally increasing prevalence of MetS and its related abnormalities, attention to safe and effective prevention and treatment of this complex disorder has been increased. In particular, most treatments have been devoted to using natural agents that could provide more reliable and effective medicinal products with fewer side effects. Portulaca oleracea L. (purslane) is an herb whose therapeutic properties could be found in some ancient medical books. Purslane has shown analgesic, antispasmodic, skeletal muscle relaxant, bronchodilator, antiasthmatic, anti-inflammatory, antiseptic, diuretic, antibacterial, antipyretic, and wound-healing properties. In addition, purslane's hypoglycemic and hypolipidemic properties have been reported in different studies. The positive effects of this plant include reducing stress oxidative and inflammation along with the atherogenic index, improving insulin level and glucose uptake, decreasing lipid profiles, and ameliorating weight gain. These activities could reduce MetS complications. This review aims to provide a comprehensive overview of various in vitro, animal, and human studies regarding the effect of Portulaca oleracea on metabolic syndrome to better understand the underlying mechanisms of action for designing more effective treatments.

SARS-CoV-2 mRNA-vaccine candidate; COReNAPCIN®, induces robust humoral and cellular immunity in mice and non-human primates.

At the forefront of biopharmaceutical industry, the messenger RNA (mRNA) technology offers a flexible and scalable platform to address the urgent need for world-wide immunization in pandemic situations. This strategic powerful platform has recently been used to immunize millions of people proving both of safety and highest level of clinical efficacy against infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Here we provide preclinical report of COReNAPCIN®; a vaccine candidate against SARS-CoV-2 infection. COReNAPCIN® is a nucleoside modified mRNA-based vaccine formulated in lipid nanoparticles (LNPs) for encoding the full-length prefusion stabilized SARS-CoV-2 spike glycoprotein on the cell surface. Vaccination of C57BL/6 and BALB/c mice and rhesus macaque with COReNAPCIN® induced strong humoral responses with high titers of virus-binding and neutralizing antibodies. Upon vaccination, a robust SARS-CoV-2 specific cellular immunity was also observed in both mice and non-human primate models. Additionally, vaccination protected rhesus macaques from symptomatic SARS-CoV-2 infection and pathological damage to the lung upon challenging the animals with high viral loads of up to 2 × 108 live viral particles. Overall, our data provide supporting evidence for COReNAPCIN® as a potent vaccine candidate against SARS-CoV-2 infection for clinical studies.

3D Bioprinted Hydrogel Microfluidic Devices for Parallel Drug Screening.

Conventional high-throughput screening (HTS) platforms suffer from the need for large cell volumes, high reagent consumption, significant assembly cost, and handling efforts. The assembly of three-dimensional (3D) bioprinted hydrogel-based microfluidic chips within platforms can address these problems. We present a continuous and seamless manufacturing approach to create a bioprinted microfluidic chips with a circular pattern scalable toward HTS platforms. Digital light processing 3D bioprinting is used to tune the local permeability of our chip, made of polyethylene glycol diacrylate and cell-laden gelatin methacryloyl, for creating predefined gradients of biochemical properties. We measured the flow-induced physical characteristics, the mass transport of drug agents, and the biological features of the proposed chip. We measured reactive oxygen species from the encapsulated cells through an integrated process and showed the capacity of the hydrogel-based chip for creating drug/agent gradients. This work introduces a chip design based on a hydrogel that can be changed and could be used for modern HTS platforms such as in vitro organoids.

A whole-thermoplastic microfluidic chip with integrated on-chip micropump, bioreactor and oxygenator for cell culture applications.

Microfluidics provides enabling platforms for various cell culture, drug testing and synthesis of drug carriers using chip-based microsystems. In this study, we present a novel integrated whole-thermoplastic microfluidic chip to provide a platform for on-chip cell culture at static and dynamic conditions. The whole chip was made of polymethyl methacrylate (PMMA) and thermoplastic polyurethane (TPU) using high precision micromilling and laser micromachining, assembled by thermal fusion bonding. Prior to fabricate the integrated microchip, a pneumatic solo diffuser-nozzle micropump was fabricated and characterized to evaluate its functionality for on-chip pumping. Then the micropump was integrated with a microbioreactor and an oxygenator in a microchip for flow pumping required for on-chip cell culture. Oxygenator, made of a thin TPU membrane and a reservoir, was implemented in the microchip because of low oxygen permeability of PMMA. To design the oxygenator for sufficient oxygen delivery to the chip, numerical simulation was performed using COMSOL Multiphysics® to evaluate oxygen concentration distribution inside the microchip. Finally, the diffuser-nozzle micropump was integrated with the oxygenator and a bioreactor on the microchip for cell culture with on-chip pumping. Culture of DFW cells was performed on the integrated chip for three days, and cell survival was evaluated with Trypan Blue assay. The findings reveal that the proposed integrated chip with on-chip pumping could be employed for conducting various cell culture studies.

Nanofibrous polycaprolactone/chitosan membranes for preventing postsurgical tendon adhesion.

Peritendinous adhesion is considered a major postsurgical tendon complication in hand surgery. This complication could be mitigated partially through early tendon mobilization. However, development of new treatment modalities to guide tissue regeneration and to reduce postsurgical tendon adhesion has recently gained attentions. In this article, synthesis and characterization of electrospun nanofibrous membranes (NFMs) of polycaprolactone (PCL) and chitosan to form a physical barrier against cellular migration leading to tendon adhesion is presented. The mechanical properties of the NFMs are modulated to maintain high integrity during postsurgical tendon mobilization. The tensile strength of the NFMs is examined in wet and dry conditions after 1000 cyclic pull loadings. In addition, the mechanical strength of the NFMs is evaluated after a degradation period of 30 days. To obtain NFM with desired properties, concentrations of polymer solutions, operation parameters of electrospinning and the thickness of NFMs were optimized. Based on the biodegradation and mechanical evaluations, the optimum NFM was obtained for specified amounts of PCL (5 wt %) + chitosan (2 wt %) at an electrospinning drum speed of 400 rpm. The engineered NFM could withstand forces of 33 and 19 N before and after 1000 pull cycles that are sufficient during tendon healing process. The bonding of chitosan fibers over PCL nanofibers allowed for production of NFMs with appropriate mechanical integrity and degradation rate. In vitro cell culture tests demonstrated that PCL/chitosan could only have minor impact on decreasing fibroblast attachment over the membranes probably due to protonation of amine groups.

Length of Plates and Number of Screws for the Fixation of Distal Humerus Fractures: A Finite Element Biomechanical Study.

PURPOSE: We performed a biomechanical analysis using the finite element method to assess the effects of plate length and the number of screws on construct stiffness, stress distribution, and fracture displacement in the fixation of type A2 distal humerus fractures. METHODS: A 3-dimensional humerus model was constructed using computed tomography of a healthy man. After creating a 2-mm extra-articular fracture gap, orthogonal double-plate fixation was performed with an incremental increase in plate length and the number of screws, creating 17 fixation models. Four screws were placed in each plate's distal segment, and the number of screws was increased incrementally in the segment proximal to the fracture, starting from 2 in the medial (M) and 2 in the lateral (L) plate (M2∗L2). RESULTS: The fifth screw proximal to the fracture in the lateral plate (L5) played an essential role in increasing stiffness under bending, axial, and torsional forces surpassing the intact bone, which may have been due to the bypassing of the stress riser area. Minimum construct stiffness was created when 5 (M3∗L2) screws were inserted into the proximal segment. For bending forces, the M4∗L2 construct was stronger than M3∗L3 (total 6 proximal screws), and M5∗L3 was stronger than M4∗L4 (total 8 proximal screws), showing higher stiffness when the plates ended at different levels. The M4∗L2 construct (6 screws) had stiffness comparable with M4∗L3, M4∗L4, and M5∗L4 during bending, showing comparable stiffness with the least instrumentation density. CONCLUSION: Our findings suggested M3∗L5 as the optimum and M3∗L2 as the minimum construct to resist all bending, axial and torsional forces. CLINICAL RELEVANCE: Applying the results may improve surgical techniques, decrease the rate of complications, including fixation failure and nerve injury, and optimize the time of surgery. Moreover, hardware removal is less cumbersome with fewer screws.

3D printing-assisted fabrication of a patient-specific antibacterial radial head prosthesis with high periprosthetic bone preservation.

We present a novel fabrication and surgical approach for anatomical reconstruction of a fractured radial head using a patient-specific radial head prosthesis (RHP) made of polymethylmethacrylate (PMMA) bone cement. To this end, the use of PMMA bone cement for prosthesis fabrication was initially investigated using computational modeling and experimental methods. The RHP was fabricated through casting of PMMA bone cement in a silicone mold in the operating room before implantation. To enhance the precision of bony preparation for replacement of the radial head, a patient-specific surgical guide for accurate resection of the radial neck with the desired length was developed. Post-surgical clinical examinations revealed biomechanical restoration of elbow function, owing to the use of the patient-specific RHP and surgical guide. Importantly, follow-up radiographs after a mean follow-up of 18 months revealed bone preservation at the bone-prosthesis interface without any signs of erosion of the capitellum. Taken together, our method demonstrated the safety and efficacy of the PMMA RHP in restoring elbow biomechanics. This also provides a very safe and cost-effective method for making various patient-specific prostheses with localized antibacterial delivery and close mechanical properties to native bone for improved periprosthetic bone regeneration. The clinical trial of this study was registered at Mashhad University of Medical Sciences under the trial registration number 970493.

Investigation of the emission spectra and cytotoxicity of TiO2 and Ti-MSN/PpIX nanoparticles to induce photodynamic effects using X-ray.

BACKGROUND: Photodynamic therapy (PDT) has been recognized as an effective method for cancer treatment; however, it suffers from limited tissue penetration depth. X-rays are ideal excitation sources for activating self-lighting nanoparticles that can penetrate through deep tumor tissues and convert the X-rays to visible light. In this study, Ti-MSN/PpIX nanoparticles for X-ray induced photodynamic therapy was synthesized. Preparation, characterization, and emission spectrum of Ti-MSN/PpIX nanoparticles as well as PDT activity and toxicity of the nanoparticles on HT-29 cell line were investigated. METHODS: Firstly, mesoporous silica nanoparticles (MSN) were synthesized through sol-gel method. Then, TiO2 and PpIX were loaded in MSN. Next, the emission spectra of TiO2, Ti-MSN, and Ti-MSN/PpIX nanoparticles, while activated by X-ray (6 MVp), were recorded. In addition, viability of cells after treatment by Ti-MSN/PpIX nanoparticles and X-ray irradiation was studied. RESULTS: SEM, TEM and FESEM images of the spherical composite nanoparticles showed that their dimensions were changed by incorporating Ti and organic compound of PpIX. Two-dimensional hexagonal structure with d100-spacing was about 3.5 nm with particle sizes of 70-110 nm. The optical characteristics of TiO2 nanoparticles showed strong emission lines, which effectively overlapped with the absorption wavelengths of protoporphyrin IX (PpIX). Cellular experiments showed Ti-MSN/PpIX nanoparticles have proper biocompatibility, however, after X-ray irradiation, significant decrease of cell viability in the presence of the nanoparticles was observed. CONCLUSION: The presented X-PDT method could enhance RT efficacy and is enable that allows for reducing X-ray dose exposure to healthy tissues to overcome radio-resistant tumors.

Electrospun Nanofibrous Membranes for Preventing Tendon Adhesion.

Tendon injuries are frequent, and surgical interventions toward their treatment might result in significant clinical complications. Pretendinous adhesion results in the disruption of the normal gliding mechanism of a damaged tendon, painful movements, and an increased chance of rerupture in the future. To alleviate postsurgical tendon-sheath adhesions, many investigations have been directed toward the development of repair approaches using electrospun nanofiber scaffolds. Such methods mainly take advantage of nanofibrous membranes (NFMs) as physical barriers to prevent or minimize adhesion of a repaired tendon to its surrounding sheath. In addition, these nanofibers can also locally deliver antiadhesion and anti-inflammatory agents to reduce the risk of tendon adhesion. This article reviews recent advances in the design, fabrication, and characterization of nanofibrous membranes developed to serve as (i) biomimetic tendon sheaths and (ii) physical barriers. Various features of the membranes are discussed to present insights for further development of repair methods suitable for clinical practice.

Miniaturised acoustofluidic tactile haptic actuator.

Tactile haptic feedback is an important consideration in the design of advanced human-machine interfaces, particularly in an age of increasing reliance on automation and artificial intelligence. In this work, we show that the typical nanometer-order surface displacement amplitudes of piezoelectric transducers-which are too small to be detectable by the human touch, and constitute a significant constraint in their use for tactile haptic surface actuation-can be circumvented by coupling the vibration into a liquid to drive the deflection of a thermoplastic membrane. In particular, transmission of the sound energy from the standing wave vibration generated along a piezoelectric transducer into a microfluidic chamber atop which the membrane is attached is observed to amplify the mechanical vibration signalling through both the acoustic radiation pressure and the viscous normal stress acting on the membrane-the latter arising due to the acoustic streaming generated as the sound wave propagates through the liquid-to produce 100 µm-order static deflections of the membrane, upon which approximately 0.5 µm dynamic vibrations at frequencies around 1 kHz are superimposed; both these static and dynamic responses are within the perception range for human finger sensation. The large static deformation, the relatively fast response time, and the ability to incorporate a dynamic vibrotactile response together with the small size and potential for integration of the device into large scale arrays make this mechanism well suited for driving actuation in devices which require tactile haptic responses.

Breathable hydrogel dressings containing natural antioxidants for management of skin disorders.

Traditional wound dressings are not effective enough to regulate the moisture content and remove excessive exudate from the environment. Wet wound dressings formed from hydrogels such as alginate are widely used in clinical practice for treatment of skin disorders. Here, we functionalize alginate dressings with natural antioxidants such as curcumin and t-resveratrol to render them both anti-inflammatory and antibacterial. The hydrogel maintains excellent mechanical properties and oxygen permeability over time. The release rate of the compounds from the hydrogels is assessed and their impact on bacterial and cellular growth is evaluated. The antioxidant compounds act as bactericidal agents and improve cell viability. The optimal concentration of active compounds in the engineered alginate-based dressings is determined.

Micro and nanotechnologies for bone regeneration: Recent advances and emerging designs.

Treatment of critical-size bone defects is a major medical challenge since neither the bone tissue can regenerate nor current regenerative approaches are effective. Emerging progresses in the field of nanotechnology have resulted in the development of new materials, scaffolds and drug delivery strategies to improve or restore the damaged tissues. The current article reviews promising nanomaterials and emerging micro/nano fabrication techniques for targeted delivery of biomolecules for bone tissue regeneration. In addition, recent advances in fabrication of bone graft substitutes with similar properties to normal tissue along with a brief summary of current commercialized bone grafts have been discussed.

Ultrasensitive detection of ochratoxin A using aptasensors.

Regarding teratogenic, carcinogenic, and immunotoxic nature of ochratoxin A (OTA), selective and sensitive monitoring of this molecule in food samples is of great importance. In recent years, various methods have been introduced for detection of OTA. However, they are usually time-consuming, labor-intensive and expensive. Therefore, these parameters limited their usage. The emerging method of detection, aptasensor, has attracted more attention for OTA detection, due to distinctive advantages including high sensitivity, selectivity and simplicity. In this review, the new developed aptasensors for detection of OTA have been investigated. We also highlighted advantages and disadvantages of different types of OTA aptasensors. This review also takes into consideration the goal to find out which designs are the most rational ones for highly sensitive detection of OTA.

Multisensor-integrated organs-on-chips platform for automated and continual in situ monitoring of organoid behaviors.

Organ-on-a-chip systems are miniaturized microfluidic 3D human tissue and organ models designed to recapitulate the important biological and physiological parameters of their in vivo counterparts. They have recently emerged as a viable platform for personalized medicine and drug screening. These in vitro models, featuring biomimetic compositions, architectures, and functions, are expected to replace the conventional planar, static cell cultures and bridge the gap between the currently used preclinical animal models and the human body. Multiple organoid models may be further connected together through the microfluidics in a similar manner in which they are arranged in vivo, providing the capability to analyze multiorgan interactions. Although a wide variety of human organ-on-a-chip models have been created, there are limited efforts on the integration of multisensor systems. However, in situ continual measuring is critical in precise assessment of the microenvironment parameters and the dynamic responses of the organs to pharmaceutical compounds over extended periods of time. In addition, automated and noninvasive capability is strongly desired for long-term monitoring. Here, we report a fully integrated modular physical, biochemical, and optical sensing platform through a fluidics-routing breadboard, which operates organ-on-a-chip units in a continual, dynamic, and automated manner. We believe that this platform technology has paved a potential avenue to promote the performance of current organ-on-a-chip models in drug screening by integrating a multitude of real-time sensors to achieve automated in situ monitoring of biophysical and biochemical parameters.

A novel fluorescent aptasensor for ultrasensitive detection of microcystin-LR based on single-walled carbon nanotubes and dapoxyl.

To assure water safety and protect human health, precise and simple analytical approaches are highly desired to determine low concentrations of microcystin-leucine-arginine (MC-LR), a toxin, in both water and serum samples. Herein, a simple, rapid and accurate aptamer-based fluorescent sensor was used for selective recognition of MC-LR, based on single-walled carbon nanotubes (SWNTs) as immobilizers, dapoxyl as a fluorescent dye, DAP-10 as a specific aptamer for dapoxyl and unmodified MC-LR aptamer (Apt) as a sensing ligand. The sensing method was developed to produce a remarkable fluorescence intensity difference in the absence and presence of MC-LR. Moreover, the Apt was used without any modification. In the absence of MC-LR, the dapoxyl could bind to DAP-10, leading to a strong fluorescence intensity. In the presence of MC-LR, DAP-10 bound to the surface of SWNTs, resulting in a very weak fluorescence intensity. Under optimized conditions, the presented fluorescent analytical approach showed high selectivity toward MC-LR with a limit of detection (LOD) of 138 pM. This new method indicated excellent analytical performance for MC-LR detection in tap water and serum samples with LODs of 135 and 168 pM, respectively.