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Organic phase-change materials (PCMs) hold promise in developing advanced thermoregulation and responsive energy systems owing to their high latent heat capacity and thermal reliability. However, organic PCMs are prone to leakages in the liquid state and, thus, are hardly applicable in their pristine form. Herein, we encapsulated organic PCM n-Octadecane into polyurethane capsules via polymerization of commercially available polymethylene polyphenylene isocyanate and polyethylene glycol at the interface oil-in-water emulsion and studied how various n-Octadecane feeding affected the shell formation, capsule structure, and latent heat storage properties. The successful shell polymerization and encapsulation of n-Octadecane dissolved in the oil core was verified by confocal microscopy and Fourier-transform infrared spectroscopy. The mean capsule size varied from 9.4 to 16.7 µm while the shell was found to reduce in thickness from 460 to 220 nm as the n-Octadecane feeding increased. Conversely, the latent heat storage capacity increased from 50 to 132 J/g corresponding to the growth in actual n-Octadecane content from 25% to 67% as revealed by differential scanning calorimetry. The actual n-Octadecane content increased non-linearly along with the n-Octadecane feeding and reached a plateau at 66–67% corresponded to 3.44–3.69 core-to-monomer ratio. Finally, the capsules with the reasonable combination of structural and thermal properties were evaluated as a thermoregulating additive to a commercially available paint. [ABSTRACT FROM AUTHOR]

• Freezing induced loading and Layer by Layer methods were used for capsule preparation. • The release of Cy7 labeled BSA initially quenched by magnetite was shown in vivo. • The decrease of Cy7 fluorescence after HIFU due to reactive oxygen species was observed. • Fast time- and site-specific release of Cy7-BSA in vivo under HIFU was demonstrated. High intensity focused ultrasound (HIFU) is widely used in medical practice, including cancer therapy. Also this approach is promising for remote release of encapsulated drugs in various other biomedical applications where local treatment is needed. Our approach underpins the minimization of HIFU impact on possible degradation of biological tissues and expand the use of HIFU in the controlled release of encapsulated drugs. We demonstrated the efficient ultrasound-induced release of labeled protein (Cy7-BSA) from elaborated nanocomposite microcapsules in vitro an in vivo. The capsule fabrication was done using combination of recently developed freezing-induced loading (FIL) technique and Layer-by-Layer assembly (LbL) used for the preparation of complex multilayer BSA/tannic acid nanocomposite capsules sensitive to HIFU. These capsules contain NIR fluorescent Cy7-labeled BSA in the shell for tracking in vivo and the high concentration of labels inside the capsules resulted in self-quenching provides the real-time detection of the protein once it is released from the capsule. Ultrasound-induced release in vivo of Cy7-labeled BSA initially quenched by magnetite nanoparticles was confirmed by fluorescent tomography. The significant decrease of Cy7 fluorescence under HIFU treatment in vitro was found to be due to a generation of reactive oxygen species and fast dye oxidation. Our results demonstrate that adapted HIFU setup can be used for the directed release of encapsulated substances in vivo under tissue compatible NIR monitoring by fluorescent tomography. [ABSTRACT FROM AUTHOR]

The increased research activity aiming at improved delivery of pharmaceutical molecules indicates the expansion of the field. An efficient therapeutic delivery approach is based on the optimal choice of drug-carrying vehicle, successful targeting, and payload release enabling the site-specific accumulation of the therapeutic molecules. However, designing the formulation endowed with the targeting properties in vitro does not guarantee its selective delivery in vivo. The various biological barriers that the carrier encounters upon intravascular administration should be adequately addressed in its overall design to reduce the off-target effects and unwanted toxicity in vivo and thereby enhance the therapeutic efficacy of the payload. Here, we discuss the main parameters of remote-controlled drug delivery systems: (i) key principles of the carrier selection; (ii) the most significant physiological barriers and limitations associated with the drug delivery; (iii) major concepts for its targeting and cargo release stimulation by external stimuli in vivo. The clinical translation for drug delivery systems is also described along with the main challenges, key parameters, and examples of successfully translated drug delivery platforms. The essential steps on the way from drug delivery system design to clinical trials are summarized, arranged, and discussed. [ABSTRACT FROM AUTHOR]

Flow cytometry nowadays is among the main working instruments in modern biology paving the way for clinics to provide early, quick, and reliable diagnostics of many blood-related diseases. The major problem for clinical applications is the detection of rare pathogenic objects in patient blood. These objects can be circulating tumor cells, very rare during the early stages of cancer development, various microorganisms and parasites in the blood during acute blood infections. All of these rare diagnostic objects can be detected and identified very rapidly to save a patient's life. This review outlines the main techniques of visualization of rare objects in the blood flow, methods for extraction of such objects from the blood flow for further investigations and new approaches to identify the objects automatically with the modern deep learning methods. [ABSTRACT FROM AUTHOR]

Adsorption of organic phase-change materials (PCMs) by the porous matrix of microfibrillar cellulose (MFC) is a simple and versatile way to prepare shape-stable phase-change composites, which are promising as sustainable thermoregulating additives to construction materials. However, due to MFC inherent morphology, the resulting composites have relatively low poured density that complicates their introduction in sufficient amounts, for instance, into mortar mixes. Unlike MFC, fungal mycelium has, by an order, less fibrils thickness and, thus, possesses significantly higher poured density. Herein, we studied the feasibility of fungal mycelium-based matrices as alternative biopolymeric porous supports for preparation of sustainable and shape-stable phase-change composites. Two methods were employed to prepare the porous mycelium-based supports. The first one was the solid-state fermentation, which resulted in partial biotransformation of MFCs to mycelium hyphae, while the second one was the liquid-state surface fermentation, used to cultivate the reference matrix of Trametes hirsuta hyphae. The phase-change composites were prepared by adsorption of model organic PCMs on porous biopolymer matrices. The mass ratio of support/PCM was 40/60 wt%. The composites were studied with respect to their structure, composition, poured density, latent heat storage properties, and thermal and shape stability. The employment of the partially transformed to mycelium-hyphae MFC fibers was found to be a suitable way to prepare phase-change composites with improved poured density while preserving a reasonable latent heat capacity and shape stability as compared to the MFC/PCM composites. [ABSTRACT FROM AUTHOR]

Hybrid carriers with the mineral CaCO3/Fe3O4 core and the protein-tannin shell are attractive for drug delivery applications due to reliable coupling of anticancer drugs with protein-tannin complex and the possibility of remote control over drug localization and delivery by the external magnetic field. This study aims to elucidate the mechanisms of drug release via enzymatic degradation of a protein-tannin carrier shell triggered by proteolytic hydrolases trypsin and pepsin under physiological conditions. To do this, the carriers were incubated with the enzyme solutions in special buffers to maintain the enzyme activity. The time-lapse spectrophotometric and electron microscopy measurements were carried out to evaluate the degradation of the carriers. It was established that the protein-tannin complex demonstrates the different degradation behavior depending on the enzyme type and buffer medium. The incubation in trypsin solution mostly resulted in the protein shell degradation. The incubation in pepsin solution did not affect the protein component; however, the citric buffer stimulates the degradation of the mineral core. The presented results allow for predicting the degradation pathways of the carriers including the release profile of the loaded cargo under physiological conditions. The viability of 4T1 breast cancer cells with mineral magnetic carriers with protein-tannin shells was investigated, and their movement in the fields of action of the permanent magnet was shown. [ABSTRACT FROM AUTHOR]

We demonstrate a novel approach to the controlled loading of inorganic nanoparticles and proteins into submicron- and micron-sized porous particles. The approach is based on freezing/thawing cycles, which lead to high loading densities. The process was tested for the inclusion of Au, magnetite nanoparticles, and bovine serum albumin in biocompatible vaterite carriers of micron and submicron sizes. The amounts of loaded nanoparticles or substances were adjusted by the number of freezing/thawing cycles. Our method afforded at least a three times higher loading of magnetite nanoparticles and a four times higher loading of protein for micron vaterite particles, in comparison with conventional methods such as adsorption and coprecipitation. The capsules loaded with magnetite nanoparticles by the freezing-induced loading method moved faster in a magnetic field gradient than did the capsules loaded by adsorption or coprecipitation. Our approach allows the preparation of multicomponent nanocomposite materials with designed properties such as remote control (e.g. via the application of an electromagnetic or acoustic field) and cargo unloading. Such materials could be used as multimodal contrast agents, drug delivery systems, and sensors. [ABSTRACT FROM AUTHOR]