Recent advances towards point-of-care devices for fungal detection: Emphasizing the role of plasmonic nanomaterials in current and future technologies.

Fungal infections are a significant global health problem, particularly affecting individuals with weakened immune systems. Moreover, as uncontrolled antibiotic and immunosuppressant use increases continuously, fungal infections have seen a dramatic increase, with some strains developing antibiotic resistance. Traditional approaches to identifying fungal strains often rely on morphological characteristics, thus owning limitations, such as struggles in identifying several strains or distinguishing between fungal strains with similar morphologies. This review explores the multifaceted impact of fungi infections on individuals, healthcare providers, and society, highlighting the often-underestimated economic burden and healthcare implications of these infections. In light of the serious constraints of traditional fungal identification methods, this review discusses the potential of plasmonic nanoparticle-based biosensors for fungal infection identification. These biosensors can enable rapid and precise fungal pathogen detection by exploiting several readout approaches, including various spectroscopic techniques, colorimetric and electrochemical assays, as well as lateral-flow immunoassay methods. Moreover, we report the remarkable impact of plasmonic Lab on a Chip technology and microfluidic devices, as they recently emerged as a class of advanced biosensors. Finally, we provide an overview of smartphone-based Point-of-Care devices and the associated technologies developed for detecting and identifying fungal pathogens.

NIR photothermal-activable drug-conjugated microcapsules for in vitro targeted delivery and release: An alternative treatment of diabetic retinopathy.

Diabetic retinopathy (DR) is one of the most serious complications of diabetes, which leads to blindness. By addressing the traditional treatment limitations, we developed a novel light-responsive targeted polymeric microcapsule able to encapsulate a near infrared (NIR) photoactive fluorophore - Indocyanine Green, owing to its photothermal properties. Moreover, for an efficient in vitro targeted drug delivery, the fluorescent microsystem was conjugated with a therapeutic agent, i.e., Avastin drug - a Food and Drug Administration approved therapeutic antibody. The microcapsules were fabricated and evaluated in terms of morphology, encapsulation and drug conjugation efficiency and its release capacity. Avastin-conjugated microcapsules with an average dimension of 4.5 ± 0.35 µm were obtained, according to Scanning Electron Microscopy and Re-Scanning Confocal Microscopy (RCM) investigations. The capacity of the microcapsules to operate as effective phototherapeutic agents by generating heat under NIR laser irradiation was evaluated, followed by the investigation of the microcapsule's shell rupture and NIR laser-induced release of Avastin. The biocompatibility of the Avastin-conjugated microcapsules was proven by WST-1 assay. In vitro cellular internalization and localization of the Avastin microcarriers were determined through Conventional fluorescence microscopy, RCM and Transmission Electron Microscopy imaging techniques. Finally, the Avastin-conjugated microcapsules were validated for in vitro targeted drug delivery and release directly under simulated DR conditions, which could certainly become a successful strategy in DR fighting.

Hybrid polymeric therapeutic microcarriers for thermoplasmonic-triggered release of resveratrol.

Diabetic retinopathy (DR) is a severe ocular complication that causes retinal damage, being one of the leading causes of blindness globally, thus the development of new strategies to prevent and treat DR as well as other degenerative diseases is highly desired. This work is focused on the design and fabrication of an ingenious model of polymeric microcapsules (MC) for controlled drug delivery in human retina cells able to carry therapeutic resveratrol (RSV) molecules in tandem with active anisotropic gold bipyramidal nanoparticles (AuBPs) as efficient photothermal agents. Specifically, MC were developed via a Layer-by-Layer deposition technique, by successively adding oppositely charged polyelectrolytes on a RSV-conjugated calcium carbonate (CaCO3) core. For the monitorization and localization of the as-formed spherical fluorescent MC inside human retina pigmented epithelial (RPE) D407 cells, fluorescein isothiocyanate, a Food and Drug Administration approved fluorophore, was attached between the polyelectrolytes layers. High-performance liquid chromatography analysis revealed a loading efficiency of over 90% of RSV on the CaCO3 core and demonstrates its release upon NIR irradiation as a consequence of the thermoplasmonic effect of MC. The cytotoxicity of the RSV-carrying MC inside human retina cells was assessed by WST-1 assay. Finally, cellular internalization and localization of the MC inside living RPE cells were monitored via Conventional Fluorescence and Re-Scanning Confocal Fluorescence Microscopy. This research seeks to take use of the novel MC and implement them as potential intraocular RSV delivery vehicles for the therapy of DR.

Antibody-functionalized theranostic protein nanoparticles for the synergistic deep red fluorescence imaging and multimodal therapy of ovarian cancer.

Among women, ovarian cancer is the fifth most frequent type of cancer, and despite benefiting from current standard treatment plans, 90% of patients relapse in the subsequent 18 months and, eventually, perish. As a result, via embracing nanotechnological advancements in the field of medical science, researchers working in the areas of cancer therapy and imaging are looking for the next breakthrough treatment strategy to ensure lower cancer recurrence rates and improved outcomes for patients. Herein, we design a novel phototheranostic agent with optical features in the biological window of the electromagnetic spectrum via encapsulating a newly synthesized phthalocyanine dye within biocompatible protein nanoparticles, allowing the targeted fluorescence imaging and synergistic dual therapy of ovarian cancer. The nanosized agent displays great biocompatibility and enhanced aqueous biostability and photothermal activity, as well as high reactive-oxygen-species generation efficiency. To achieve the active targeting of the desired malignant tissue and suppress the rapid clearance of the photosensitive agent from the peritoneal cavity, the nanoparticles are biofunctionalized with an anti-folate receptor antibody. A2780 ovarian cancer cells are employed to confirm the improved targeting capabilities and the in vitro cytotoxic efficiency of the theranostic nanoparticles after exposure to a 660 nm LED lamp; upon measurement via MTT and flow cytometry assays, a significant 95% decrease in the total number of viable cells is seen. Additionally, the therapeutic performance of our newly designed nanoparticles was evaluated in vivo, via real-time thermal monitoring and histopathological assays, upon the irradiation of tumour-bearing mice with a 660 nm LED lamp (0.05 W cm-2). Foremost, separately from steady-state fluorescence imaging, we found that, via utilizing FLIM investigations, the differences in fluorescence lifetimes of antibody biofunctionalized and non-functionalized nanoparticles can be correlated to different intracellular localization and internalization pathways of the fluorescent agent, which is relevant for the development of a cutting-edge method for the detection of cancer cells that overexpress folate receptors at their surfaces.

Fluorescent Phthalocyanine-Encapsulated Bovine Serum Albumin Nanoparticles: Their Deployment as Therapeutic Agents in the NIR Region.

In recent times, researchers have aimed for new strategies to combat cancer by the implementation of nanotechnologies in biomedical applications. This work focuses on developing protein-based nanoparticles loaded with a newly synthesized NIR emitting and absorbing phthalocyanine dye, with photodynamic and photothermal properties. More precisely, we synthesized highly reproducible bovine serum albumin-based nanoparticles (75% particle yield) through a two-step protocol and successfully encapsulated the NIR active photosensitizer agent, achieving a good loading efficiency of 91%. Making use of molecular docking simulations, we confirm that the NIR photosensitizer is well protected within the nanoparticles, docked in site I of the albumin molecule. Encouraging results were obtained for our nanoparticles towards biomedical use, thanks to their negatively charged surface (-13.6 ± 0.5 mV) and hydrodynamic diameter (25.06 ± 0.62 nm), favorable for benefitting from the enhanced permeability and retention effect; moreover, the MTT viability assay upholds the good biocompatibility of our NIR active nanoparticles. Finally, upon irradiation with an NIR 785 nm laser, the dual phototherapeutic effect of our NIR fluorescent nanoparticles was highlighted by their excellent light-to-heat conversion performance (photothermal conversion efficiency 20%) and good photothermal and size stability, supporting their further implementation as fluorescent therapeutic agents in biomedical applications.