Recent Trends and Innovations in Bead-Based Biosensors for Cancer Detection.

Demand is strong for sensitive, reliable, and cost-effective diagnostic tools for cancer detection. Accordingly, bead-based biosensors have emerged in recent years as promising diagnostic platforms based on wide-ranging cancer biomarkers owing to the versatility, high sensitivity, and flexibility to perform the multiplexing of beads. This comprehensive review highlights recent trends and innovations in the development of bead-based biosensors for cancer-biomarker detection. We introduce various types of bead-based biosensors such as optical, electrochemical, and magnetic biosensors, along with their respective advantages and limitations. Moreover, the review summarizes the latest advancements, including fabrication techniques, signal-amplification strategies, and integration with microfluidics and nanotechnology. Additionally, the challenges and future perspectives in the field of bead-based biosensors for cancer-biomarker detection are discussed. Understanding these innovations in bead-based biosensors can greatly contribute to improvements in cancer diagnostics, thereby facilitating early detection and personalized treatments.

Multifunctional Protein Hybrid Nanoplatform for Synergetic Photodynamic-Chemotherapy of Malignant Carcinoma by Homologous Targeting Combined with Oxygen Transport.

Photodynamic therapy (PDT) under hypoxic conditions and drug resistance in chemotherapy are perplexing problems in anti-tumor treatment. In addition, central nervous system neoplasm-targeted nanoplatforms are urgently required. To address these issues, a new multi-functional protein hybrid nanoplatform is designed, consisting of transferrin (TFR) as the multicategory solid tumor recognizer and hemoglobin for oxygen supply (ODP-TH). This protein hybrid framework encapsulates the photosensitizer protoporphyrin IX (PpIX) and chemotherapeutic agent doxorubicin (Dox), which are attached by a glutathione-responsive disulfide bond. Mechanistically, ODP-TH crosses the blood-brain barrier (BBB) and specifically aggregated in hypoxic tumors via protein homology recognition. Oxygen and encapsulated drugs ultimately promote a therapeutic effect by down-regulating the abundance of multidrug resistance gene 1 (MDR1) and hypoxia-inducible factor-1-α (HIF-1α). The results reveal that ODP-TH achieves oxygen transport and protein homology recognition in the hypoxic tumor occupation. Indeed, compared with traditional photodynamic chemotherapy, ODP-TH achieves a more efficient tumor-inhibiting effect. This study not only overcomes the hypoxia-related inhibition in combination therapy by targeted oxygen transport but also achieves an effective treatment of multiple tumors, such as breast cancer and glioma, providing a new concept for the construction of a promising multi-functional targeted and intensive anti-tumor nanoplatform.

Oral and nasal vaccination: current prospects, challenges, and impact of nanotechnology-based delivery systems

Abstract Currently, mucosal vaccine administration has stood out as an easier and non-invasive application method. It can also be used to induce local and systemic immune responses. In the COVID-19 pandemic context, nasal and oral vaccines have been developed based on different technological platforms. This review addressed relevant aspects of mucosal vaccine administration, with emphasis on oral and nasal vaccinations, in addition to the importance of using nanotechnology-based delivery systems to enable these strategies.

Os desafios na conduta terapêutica em pacientes acometidos com feridas crônicas / Challenges in the therapeutic conduct in patients affected with chronic wounds / Retos en la conducta terapéutica en pacientes afectados de heridas crónicas

Considerado um grave problema em saúde pública, as feridas crônicas são patologias que desafiam o manejo terapêutico e infelizmente acometem milhares de pessoas em todo o mundo. Essa doença apresenta altos índices de morbidade impactando negativamente na qualidade de vida dos seus portadores, além de influenciar negativamente no domínio "bem-estar", principalmente quando associado aos fatores clínicos podendo estar relacionado há anos de tratamento sem cura da ferida. As feridas crônicas são caracterizadas por demora ou dificuldade nos processos de cicatrização e reparação ordenada da integridade anatômica e funcional da pele durante um período de no mínimo três meses. Porém, algumas lesões permanecem por anos e até décadas sem cicatrizar. Objetivo: O escopo dessa revisão é mostrar o limitado arsenal terapêutico bem como a dificuldade no manejo clínico e dessa forma proporcionar uma reflexão sobre sua fisiopatologia e a urgente necessidade de novas opções e condutas terapêuticas que possam auxiliar no tratamento desses pacientes. Metodologia: Trata-se de uma revisão integrativa da literatura sobre feridas crônicas, cujo critérios de inclusão foram artigos publicados no período de janeiro de 2005 a fevereiro de 2023. Conclusão: A problemática acerca dessa patologia é vasta, tratando de uma doença de difícil cura, com uma gama de fatores associados que dificultam a cura da lesão, estendendo essa doença a altos índices de morbidade. Novas condutas terapêuticas e novos fármacos, precisam ser desenvolvidos urgentemente. Destaca-se que o uso de probióticos e o emprego da nanotecnologia tem mostrado um grande potencial inovador no tratamento de pacientes portadores de feridas crônicas.

Considered a serious public health problem, chronic wounds are pathologies that defy therapeutic management and unfortunately affect thousands of people around the world. This disease has high morbidity rates, negatively impacting the quality of life of its patients, in addition to negatively influencing the "well-being" domain, especially when associated with clinical factors, which may be related to years of treatment without healing of the wound. Chronic wounds are characterized by delay or difficulty in healing processes and orderly repair of the anatomical and functional integrity of the skin over a period of at least three months. However, some injuries remain for years and even decades without healing. Objective: The scope of this review is to show the limited therapeutic arsenal as well as the difficulty in clinical management and thus provide a reflection on its pathophysiology and the urgent need for new options and therapeutic approaches that can help in the treatment of these patients. Methodology: This is an integrative review of the literature on chronic wounds, whose inclusion criteria were articles published from January 2005 to February 2023. Conclusion: The problem surrounding this pathology is vast, dealing with a difficult-to-cure disease, with a range of associated factors that make healing of the lesion difficult, extending this disease to high morbidity rates. New therapeutic approaches and new drugs need to be developed urgently. It is noteworthy that the use of probiotics and the use of nanotechnology have shown great innovative potential in the treatment of patients with chronic wounds.

Consideradas un grave problema de salud pública, las heridas crónicas son patologías que desafían el manejo terapéutico y que, lamentablemente, afectan a miles de personas en todo el mundo. Esta enfermedad presenta altas tasas de morbilidad, impactando negativamente en la calidad de vida de sus pacientes, además de influir negativamente en el dominio "bienestar", especialmente cuando se asocia a factores clínicos, que pueden estar relacionados con años de tratamiento sin curación de la herida. Las heridas crónicas se caracterizan por un retraso o dificultad en los procesos de cicatrización y reparación ordenada de la integridad anatómica y funcional de la piel durante un periodo de al menos tres meses. Sin embargo, algunas heridas permanecen durante años e incluso décadas sin cicatrizar. Objetivo: El alcance de esta revisión es mostrar el limitado arsenal terapéutico así como la dificultad en el manejo clínico y así aportar una reflexión sobre su fisiopatología y la urgente necesidad de nuevas opciones y enfoques terapéuticos que puedan ayudar en el tratamiento de estos pacientes. Metodología: Se trata de una revisión integradora de la literatura sobre heridas crónicas, cuyos criterios de inclusión fueron artículos publicados desde enero de 2005 hasta febrero de 2023. Conclusiones: La problemática que rodea a esta patología es amplia, tratándose de una enfermedad de difícil curación, con una serie de factores asociados que dificultan la cicatrización de la lesión, extendiendo esta enfermedad a altas tasas de morbilidad. Es urgente desarrollar nuevos enfoques terapéuticos y nuevos fármacos. Cabe destacar que el uso de probióticos y el empleo de nanotecnología han mostrado un gran potencial innovador en el tratamiento de pacientes con heridas crónicas.

Improved antimutagenic effect of Pyrostegia venusta (Ker Gawl. ) Miers nanostructured extract in liposome and polymeric nanoparticle

Abstract Pyrostegia venusta (Ker Gawl.) Miers, popularly known as "Cipó-de São-João", has been used in traditional medicine for its therapeutic properties. Nanotechnology is able to enhance the pharmacological activity of plant extracts. In this context, liposomes and polymeric nanoparticles containing P. venusta ethanolic extract were developed and then physico-chemically characterized to evaluate the mutagenic/antimutagenic effects of P. venusta. In addition, transaminases and serum creatinine were biochemically analyzed for liver and renal damage, respectively. The micronucleus test was performed with male Swiss mice treated orally for 15 consecutive days with free extracts and nanostructured with P. venusta, and then intraperitoneally with N-ethyl-N-nitrosurea (50 mg/kg) on the 15th day of treatment. Micronucleated polychromatic erythrocytes (MNPCE) were evaluated in bone marrow. There was a significant reduction in the frequency of MNPCE (LPEPV = 183% and NPEPV = 114%, p < 0.001), indicating antimutagenic potential of the nanostructured extracts with P. venusta. The groups treated with only nanostructured extract did not show an increase in MNPCE frequency, and biochemical analyzes showed no significant difference between treatments. The liposomes and polymeric nanoparticles containing Pyrostegia venusta ethanolic extract showed biological potential in preventing the first step of carcinogenesis under the experimental conditions

Ultrasensitive detection of trypsin in serum via nanochannel device.

A highly sensitive trypsin sensing system in serum was developed by using an anodic alumina oxide (AAO)-based, trypsin substrate-decorated hybrid ion permeation membrane. Owing to the trypsin-triggered peptide hydrolyzation reaction, the surface electrical feature of the peptide-decorated hybrid ion membrane changed. The electric double layer effect reduces the effective ion current diameter in the AAO nano unit, so that the ion current rectification ratio will be enhanced, realizing the quantitative detection of trypsin. The lowest detection concentration can be achieved as low as 0.1 pM. This method is no need for sample pre-preparation, easy to operate, highly sensitive, and also applicable to other enzyme evaluation systems by changing corresponding substrates. This study provides a new idea for selective measurements of proteases in complex biological samples.

Self-rechargeable cardiac pacemaker system with triboelectric nanogenerators.

Self-powered implantable devices have the potential to extend device operation time inside the body and reduce the necessity for high-risk repeated surgery. Without the technological innovation of in vivo energy harvesters driven by biomechanical energy, energy harvesters are insufficient and inconvenient to power titanium-packaged implantable medical devices. Here, we report on a commercial coin battery-sized high-performance inertia-driven triboelectric nanogenerator (I-TENG) based on body motion and gravity. We demonstrate that the enclosed five-stacked I-TENG converts mechanical energy into electricity at 4.9 µW/cm3 (root-mean-square output). In a preclinical test, we show that the device successfully harvests energy using real-time output voltage data monitored via Bluetooth and demonstrate the ability to charge a lithium-ion battery. Furthermore, we successfully integrate a cardiac pacemaker with the I-TENG, and confirm the ventricle pacing and sensing operation mode of the self-rechargeable cardiac pacemaker system. This proof-of-concept device may lead to the development of new self-rechargeable implantable medical devices.

Curcumin-Loaded Hybrid Nanoparticles: Microchannel-Based Preparation and Antitumor Activity in a Mouse Model.

PURPOSE: To develop microchannel-based preparation of curcumin (Cur)-loaded hybrid nanoparticles using enzyme-targeted peptides and star-shaped polycyclic lipids as carriers, and to accomplish a desirable targeted drug delivery via these nanoparticles, which could improve the bioavailability and antitumor effects of Cur. METHODS: The amphiphilic tri-chaintricarballylic acid-poly (ε-caprolactone)-methoxypolyethylene glycol (Tri-CL-mPEG) and the enzyme-targeted tetra-chain pentaerythritol-poly (ε-caprolactone)-polypeptide (PET-CL-P) were synthesized. The Cur-loaded enzyme-targeted hybrid nano-delivery systems (Cur-P-NPs) were prepared by using the microfluidic continuous granulation technology. The physicochemical properties, release behavior in vitro, and stability of these Cur-P-NPs were investigated. Their cytotoxicity, cellular uptake, anti-proliferative efficacy in vitro, biodistribution, and antitumor effects in vivo were also studied. RESULTS: The particle size of the prepared Cur-P-NPs was 146.1 ± 1.940 nm, polydispersity index was 0.175 ± 0.014, zeta potential was 10.1 ± 0.300 mV, encapsulation rate was 74.66 ± 0.671%, and drug loading capacity was 5.38 ± 0.316%. The stability of Cur-P-NPs was adequate, and the in vitro release rate increased with the decrease of the environmental pH. Seven days post incubation, the cumulative release values of Cur were 52.78%, 67.39%, and 98.12% at pH 7.4, pH 6.8 and pH 5.0, respectively. Cur-P-NPs exhibited better cell entry and antiproliferation efficacy against U251 cells than the Cur-solution and Cur-NPs and were safe for use. Cur-P-NPs specifically targeted tumor tissues and inhibited their growth (78.63% tumor growth inhibition rate) with low toxic effects on normal tissues. CONCLUSION: The enzyme-targeted hybrid nanoparticles prepared in the study clearly have the tumor-targeting ability. Cur-P-NPs can effectively improve the bioavailability of Cur and have potential applications in drug delivery and tumor management.

High-Specific Isolation and Instant Observation of Circulating Tumour Cell from HCC Patients via Glypican-3 Immunomagnetic Fluorescent Nanodevice.

PURPOSE: Specific targeting receptors for efficiently capturing and applicable nanodevice for separating and instant observing of circulating tumour cells (CTC) are critical for early diagnosis of cancer. However, the existing CTC detection system based on epithelial cell adhesion molecule (EpCAM) was seriously limited by low expression and poor specificity of targeting receptors, and not instant observation in clinical application. METHODS: Herein, an alternative glypican-3 (GPC3)-based immunomagnetic fluorescent system (C6/MMSN-GPC3) for high-specific isolation and instant observation of CTC from hepatocellular carcinoma (HCC) patients' peripheral blood was developed. The high-specific HCC targeting receptor, GPC3, was employed for improving the sensitivity and accuracy in CTC detection. GPC3 monoclonal antibody (mAb) was linked to immunomagnetic mesoporous silica for specific targeting capture and separate CTC, and fluorescent molecule coumarin-6 (C6) was loaded for instant detection of CTC. RESULTS: The cell recovery (%) of C6/MMSN-GPC3 increased in 106 HL-60 cells (from 49.7% to 83.0%) and in whole blood (from 42% to 80.3%) compared with MACS® Beads. In clinical samples, the C6/MMSN-GPC3 could capture more CTC in the 13 cases of HCC patients and the capture efficiency was improved by 83.3%-350%. Meanwhile, the capture process of C6/MMSN-GPC3 was harmless, facilitating for the subsequent culture. Significantly, the C6/MMSN-GPC3 achieved the high-specific isolation and instant observation of CTC from HCC patients' blood samples, and successfully separated CTC from one patient with early stage of HCC (Stage I) and one post-surgery patient, further indicating the potential ability of C6/MMSN-GPC3 for HCC early diagnosis and prognosis evaluation. CONCLUSION: Our study provides a feasible glypican-3 (GPC3)-based immunomagnetic fluorescent system (C6/MMSN-GPC3) for high-specific isolation and instant observation of HCC CTC.

Exploiting Electrode Nanoconfinement to Investigate the Catalytic Properties of Isocitrate Dehydrogenase (IDH1) and a Cancer-Associated Variant.

Human isocitrate dehydrogenase (IDH1) and its cancer-associated variant (IDH1 R132H) are rendered electroactive through coconfinement with a rapid NADP(H) recycling enzyme (ferredoxin-NADP+ reductase) in nanopores formed within an indium tin oxide electrode. Efficient coupling to localized NADP(H) enables IDH activity to be energized, controlled, and monitored in real time, leading directly to a thermodynamic redox landscape for accumulation of the oncometabolite, 2-hydroxyglutarate, that would occur in biological environments when the R132H variant is present. The technique enables time-resolved, in situ measurements of the kinetics of binding and dissociation of inhibitory drugs.

Limitations and advances in new treatments and future perspectives of corneal blindness / Limitações e avanços em novos tratamentos e perspectivas futuras na cegueira corneal

ABSTRACT This review is intended to describe the therapeutic approaches for corneal blindness, detailing the steps and elements involved in corneal wound healing. It also presents the limitations of the actual surgical and pharmacological strategies used to restore and maintain corneal transparency in terms of long-term survival and geographic coverage. In addition, we critically review the perspectives of anabolic agents, including vitamin A, hormones, growth factors, and novel promitotic and anti-inflammatory modulators, to assist corneal wound healing. We discuss the studies involving nanotechnology, gene therapy, and tissue reengineering as potential future strategies to work solely or in combination with corneal surgery to prevent or revert corneal blindness.(AU)

RESUMO O presente trabalho traz uma revisão das abordagens terapêuticas para a cegueira da córnea. O estudo detalha as etapas e os elementos envolvidos na cicatrização da córnea. Ele mostra as limitações das estratégias cirúrgicas e farmacológicas usadas para restaurar e manter a transparência da córnea em termos de sobrevida a longo prazo e alcance geográfico. As perspectivas dos agentes anabólicos, incluindo vitamina A, hormônios, fatores de crescimento e novos moduladores pró-mitóticos e anti-inflamatórios para auxiliar a cicatrização da ferida na córnea, são revisadas criticamente. Aqui, apresentamos estudos envolvendo nanotecnologia, terapia gênica e reengenharia de tecidos como possíveis estratégias futuras para atuar de maneira isolada ou combinada com a cirurgia da córnea para prevenir ou reverter a cegueira corneana.(AU)

Microfluidics at Fiber Tip for Nanoliter Delivery and Sampling.

Delivery and sampling nanoliter volumes of liquid can benefit new invasive surgical procedures. However, the dead volume and difficulty in generating constant pressure flow limits the use of small tubes such as capillaries. This work demonstrates sub-millimeter microfluidic chips assembled directly on the tip of a bundle of two hydrophobic coated 100 µm capillaries to deliver nanoliter droplets in liquid environments. Droplets are created in a specially designed nanopipette and propelled by gas through the capillary to the microfluidic chip where a passive valve mechanism separates liquid from gas, allowing their delivery. By adjusting the driving pressure and microfluidic geometry, both partial and full delivery of 10 nanoliter droplets with 0.4 nanoliter maximum error, as well as sampling from the environment are demonstrated. This system will enable drug delivery and sampling with minimally invasive probes, facilitating continuous liquid biopsy for disease monitoring and in vivo drug screening.

Cisplatin resistance reversal in lung cancer by tumor acidity-activable vesicular nanoreactors via tumor oxidative stress amplification.

Drug resistance of cisplatin significantly limits its therapeutic efficacy in clinical applications against different cancers. Herein, we develop a novel strategy to overcome cisplatin drug resistance through sensitizing cisplatin-resistant human lung cancer cells (A549R) under amplified oxidative stress using a vesicular nanoreactor for simultaneous cisplatin delivery and H2O2 generation. We engineer the nanoreactor by the self-assembly of the amphiphilic diblock copolymers to co-deliver glucose oxidase (GOD) and cisplatin (Cis) (Cis/GOD@Bz-V). Cis/GOD@Bz-V was rationally designed to stay impermeable during blood circulation while mild acidity (pH 6.5-6.8) can activate its molecular-weight selective membrane permeability and release cisplatin locally. Diffusion of small molecules such as oxygen and glucose across the membranes can induce the in situ generation of superfluous H2O2 to promote cellular oxidative stress and sensitize A549R cells via activation of pro-apoptotic pathways. Cis/GOD@Bz-V nanoreactors could effectively kill A549R at pH 6.8 in the presence of glucose by the combination of H2O2 generation and cisplatin release. Growth of A549R xenograft tumors can be inhibited efficiently without the obvious toxic side effects via the systemic administration of Cis/GOD@Bz-V. Accordingly, the tumor acidity-activable cisplatin-loaded nanoreactors show great potential to enhance the therapeutic efficacy against cisplatin-resistant cancers.

Fluorescent sensor based on quantum dots and nano-porphyrin for highly sensitive and specific determination of ethyl carbamate in fermented food.

BACKGROUND: Ethyl carbamate (EC) is a potentially toxic carcinogen produced during fermentation and storage of fermented foods, and many countries have set thresholds for its content in food. Therefore, sensitive, rapid and accurate detection of EC is meaningful to ensure the quality of fermented food. RESULTS: This study introduces a CdTe quantum dots/nano-5,10,15,20-tetrakis (4-methoxyphenyl)-porphyrin (nano TPP-OCH3 ) fluorescence sensor system detection of EC. The specificity of this sensing mainly relies on a photo-induced electron transfer and electrostatic force interaction between EC and nano TPP-OCH3 . This sensor presented a linear range of 10 to 1000 µg L-1 (R2  = 0.9903) with a low detection limit of 7.14 µg L-1 . Meanwhile, the recovery (91.19-101.09%) and precision [relative standard deviation (RSD) = 0.64-3.05%] of the sensor for the analysis of fermented food (yellow rice wine, soy sauce, Chinese spirits, Pu-erh tea) samples were good and could meet the requirements of practical detection. Moreover, the detection results of fermented food (yellow rice wine, soy sauce, Chinese spirits, Pu-erh tea) samples by this sensor are basically consistent with those of high-performance liquid chromatography with fluorescence detector (HPLC-FLD). CONCLUSION: This method was expected to provide a potential platform for sensitive and accurate detection of EC in food safety monitoring, which would provide knowledge of the flavor and quality related to fermented food. © 2021 Society of Chemical Industry.

Cross-flow microfiltration for isolation, selective capture and release of liposarcoma extracellular vesicles.

We present a resource-efficient approach to fabricate and operate a micro-nanofluidic device that uses cross-flow filtration to isolate and capture liposarcoma derived extracellular vesicles (EVs). The isolated extracellular vesicles were captured using EV-specific protein markers to obtain vesicle enriched media, which was then eluted for further analysis. Therefore, the micro-nanofluidic device integrates the unit operations of size-based separation with CD63 antibody immunoaffinity-based capture of extracellular vesicles in the same device to evaluate EV-cargo content for liposarcoma. The eluted media collected showed ∼76% extracellular vesicle recovery from the liposarcoma cell conditioned media and ∼32% extracellular vesicle recovery from dedifferentiated liposarcoma patient serum when compared against state-of-art extracellular vesicle isolation and subsequent quantification by ultracentrifugation. The results reported here also show a five-fold increase in amount of critical liposarcoma-relevant extracellular vesicle cargo obtained in 30 min presenting a significant advance over existing state-of-art.

Exploring the heat transfer and entropy generation of Ag/Fe[Formula: see text]O[Formula: see text]-blood nanofluid flow in a porous tube: a collocation solution.

 Evaluating the entropy generation is essential in thermal systems to avoid the unnecessarily wasted thermal energy during the thermal processes. Nowadays, researchers are greatly fascinated to scrutinize the entropy generation in a human system because it is utilized as a thermodynamic approach to understand the heat transfer characteristics of cancer systems or wounded tissue and their accessibility status. Further, numerous nanoparticles have been employed as an agent to control the heat transfer of blood and wounded tissue. As a result, the present model manifests the entropy generation, flow characteristics and heat transport of Ag/Fe[Formula: see text]O[Formula: see text]-blood flow of a nanofluid in a permeable circular tube with the influence of variable electrical conductivity and linear radiation. Nonlinear transport equations are converted into ordinary differential equations by suitable similarity variables which are solved with weighted residual method. Significant parameters like Reynolds number, dimensionless permeability parameter, extending/contracting parameter, Eckert number and Hartmann number on the radial pressure, axial velocity, radial velocity and temperature are explored through graphs. The obtained results show that temperature distribution of Fe[Formula: see text]O[Formula: see text] nanoparticles is higher than Ag nanoparticle, in case of suction. The dimensionless permeability parameter has an opposite nature on the radial pressure for the suction and injection cases. Growing values of Hartmann number enhance the total entropy generation for the cases of suction and injection.

Tumor Allotransplantation in Drosophila melanogaster with a Programmable Auto-Nanoliter Injector.

This protocol describes the allotransplantation of tumors in Drosophila melanogaster using an auto-nanoliter injection apparatus. With the use of an autoinjector apparatus, trained operators can achieve more efficient and consistent transplantation results compared to those obtained using a manual injector. Here, we cover topics in a chronological fashion: from the crossing of Drosophila lines, to the induction and dissection of the primary tumor, transplantation of the primary tumor into a new adult host and continued generational transplantation of the tumor for extended studies. As a demonstration, here we use Notch intracellular domain (NICD) overexpression induced salivary gland imaginal ring tumors for generational transplantation. These tumors can first be reliably induced in a transition-zone microenvironment within larval salivary gland imaginal rings, then allografted and cultured in vivo to study continued tumor growth, evolution, and metastasis. This allotransplantation method can be useful in potential drug screening programs, as well as for studying tumor-host interactions.

Novel CMC-CdTe / ZnS QDs Nanosensor for the Detection of Anticancer Drug Epirubicin.

Epirubicin (EPI) is one of the standard anticancer drugs that apply for various cancers treatment. However, the accumulation of EPI in the human body can be highly toxic, and it causes inevitable harm to organs. As a result, the evaluation of low concentrations of this drug in body samples requires sensitive, rapid, and accurate analysis methods. The fluorescence method is an efficient way in comparison of the traditional methods such as liquid chromatography, capillary electrophoresis, and electrochemical methods. Herein, we synthesized a novel fluorescence nanosensor named CMC-CdTe/ZnS based on using quantum dots (QDs). The structure of the prepared nanosensor is confirmed by different analysis methods such as FT-IR, TGA, and TEM. Besides that, the fluorescence intensity response of CMC-CdTe/ZnS QDs in the presence of Epirubicin drug is investigated. Based on obtained results, not only this nanosensor developed, but also the fluorescence quenching was explained by the typical Stern-Volmer equation. The best linear quenching equation for entitled nanosensor in the presence of Epirubicin is F0/F = 0.0346Q + 1.08 (R2 = 0.99), and the detection limit of Epirubicin is around 0.04 × 10-6 mol/L at 25 °C. All of the results display that this method could be reliable and suitable approach for determination of Epirubicin in commercial samples as well.

Analysis of Tumor-Derived Exosomes by Nanoscale Flow Cytometry.

The study of tumor exosomes has gained relevance in the last decades due to their potential use for therapeutic and diagnostic application. Although there is extensive knowledge of exosome biology, some biological samples like tumor-derived exosomes have been difficult to characterize due to their complexity and heterogeneity. This distinctive feature makes difficult the identification of specific exosome subpopulations with a shared molecular signature that could allow for targeting of exosomes with therapeutic and diagnostic potential use in cancer patients. Nanoscale flow cytometry has lately emerged as an alternative tool that can be adapted to the study of nanoparticles, such as exosomes. However, the physicochemical properties of these particles are an important issue to consider as nanoparticles need the application of specific settings which differ from those used in conventional flow cytometry of cells. Therefore, in the last few years, one of the main aims has been the optimization of technical and experimental protocols to improve exosome analysis. In this chapter, we discuss several aspects of cytometric systems with a special emphasis in technical considerations of samples and equipment.

Nanoliter scale electrochemistry of natural and engineered electroactive bacteria.

Bacterial extracellular electron transfer (EET) is envisioned for use in applied biotechnologies, necessitating electrochemical characterization of natural and engineered electroactive biofilms under conditions similar to the target application, including small-scale biosensing or biosynthesis platforms, which is often distinct from standard 100 mL-scale stirred-batch bioelectrochemical test platforms used in the laboratory. Here, we adapted an eight chamber, nanoliter volume (500 nL) electrochemical flow cell to grow biofilms of both natural (Biocathode MCL community, Marinobacter atlanticus, and Shewanella oneidensis MR1) or genetically modified (S. oneidensis ΔMtr and S. oneidensis ΔMtr + pLB2) electroactive bacteria on electrodes held at a constant potential. Maximum current density achieved by unmodified strains was similar between the nano- and milliliter-scale reactors. However, S. oneidensis biofilms engineered to activate EET upon exposure to 2,4-diacetylphloroglucinol (DAPG) produced current at wild-type levels in the stirred-batch reactor, but not in the nanoliter flow cell. We hypothesize this was due to differences in mass transport of DAPG, naturally-produced soluble redox mediators, and oxygen between the two reactor types. Results presented here demonstrate, for the first time, nanoliter scale chronoamperometry and cyclic voltammetry of a range of electroactive bacteria in a three-electrode reactor system towards development of miniaturized, and potentially high throughput, bioelectrochemical platforms.