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1.
Cytometry A ; 103(11): 868-880, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37455600

RESUMO

Photoacoustic flow cytometry is one of the most effective approaches to detect "alien" objects in the bloodstream, including circulating tumor cells, blood clots, parasites, and emboli. However, the possibility of detecting high-amplitude signals from these objects against the background of blood depends on the parameters of the laser pulse. So, the dependencies of photoacoustic signals amplitude and number on laser pulse energy (5-150 µJ), pulse length (1, 2, 5 ns), and pulse repetition rate (2, 5, 10 kHz) for the melanoma cells were investigated. First, the PA responses of a melanoma cell suspension in vitro were measured to directly assess the efficiency of converting laser light into an acoustic signal. After it, the same dependence with the developed murine model based on constant rate melanoma cell injection into the animal blood flow was tested. Both in vivo and in vitro experiments show that signal generation efficiency increases with laser pulse energy above 15 µJ. Shorter pulses, especially 1 ns, provide more efficient signal generation as well as higher pulse rates. A higher pulse rate also provides more efficient signal generation, but also leads to overheating of the skin. The results show the limits where the photoacoustic flow cytometry system can be effectively used for the detection of circulating tumor cells in undiluted blood both for in vitro experiments and for in vivo murine models.


Assuntos
Melanoma , Células Neoplásicas Circulantes , Camundongos , Animais , Citometria de Fluxo/métodos , Células Neoplásicas Circulantes/patologia , Lasers , Melanoma/patologia , Análise Espectral
2.
Biomacromolecules ; 24(7): 3051-3060, 2023 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-37289998

RESUMO

A stimuli-responsive polymeric three-dimensional microstructured film (PTMF) is a 3D structure with an array of sealed chambers on its external surface. In this work, we demonstrate the use of PTMF as a laser-triggered stimulus-response system for local in vivo targeted blood vessels stimulation by vasoactive substances. The native vascular networks of the mouse mesentery were used as model tissues. Epinephrine and KCl were used as vasoactive agents that were sealed into individual chambers upon precipitation in the amount of pictograms. We demonstrated the method for non-damaged one-by-one chamber activation using a focused 532 nm laser light passed through biological tissues. To avoid laser-induced photothermal damage to biological tissues, the PTMF was functionalized with Nile Red dye, which effectively absorbs laser light. Chemically stimulated blood vessel fluctuations were analyzed using digital image processing methods. Hemodynamics changes were measured and visualized using the particle image velocimetry approach.


Assuntos
Lasers , Polímeros , Camundongos , Animais , Raios Infravermelhos
3.
Int J Mol Sci ; 24(17)2023 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-37686471

RESUMO

The behavior and migration of human mesenchymal stromal cells (hMSCs) are focal points of research in the biomedical field. One of the major aspects is potential therapy using hMCS, but at present, the safety of their use is still controversial owing to limited data on changes that occur with hMSCs in the long term. Fluorescent photoconvertible proteins are intensively used today as "gold standard" to mark the individual cells and study single-cell interactions, migration processes, and the formation of pure lines. A crucial disadvantage of this method is the need for genetic modification of the primary culture, which casts doubt on the possibility of exploring the resulting clones in personalized medicine. Here we present a new approach for labeling and tracking hMSCs without genetic modification based on the application of cell-internalizable photoconvertible polyelectrolyte microcapsules (size: 2.6 ± 0.5 µm). These capsules were loaded with rhodamine B, and after thermal treatment, exhibited fluorescent photoconversion properties. Photoconvertible capsules demonstrated low cytotoxicity, did not affect the immunophenotype of the hMSCs, and maintained a high level of fluorescent signal for at least seven days. The developed approach was tested for cell tracking for four days and made it possible to trace the destiny of daughter cells without the need for additional labeling.


Assuntos
Células-Tronco Mesenquimais , Humanos , Cápsulas , Comunicação Celular , Rastreamento de Células , Células Clonais , Corantes
4.
Int J Mol Sci ; 24(3)2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36769101

RESUMO

Complex immunosuppressive therapy is prescribed in medical practice to patients with glomerulonephritis to help them overcome symptoms and prevent chronic renal failure. Such an approach requires long-term systemic administration of strong medications, which causes severe side effects. This work shows the efficiency of polymer capsule accumulation (2.8 ± 0.4 µm) containing labeled etanercept (100 µg per dose) in the kidneys of mice. The comparison of injection into the renal artery and tail vein shows the significant superiority of the intra-arterial administration strategy. The etanercept retention rate of 18% and 8% ID in kidneys was found 1 min and 1 h after injection, respectively. The capsules were predominantly localized in the glomeruli after injection in mice using a model of acute glomerulonephritis. Histological analysis confirmed a significant therapeutic effect only in animals with intra-arterial administration of microcapsules with etanercept. The proposed strategy combines endovascular surgery and the use of polymer microcapsules containing a high molecular weight drug that can be successfully applied to treat a wide range of kidney diseases associated with glomerular pathology.


Assuntos
Glomerulonefrite , Camundongos , Animais , Etanercepte/uso terapêutico , Cápsulas , Glomerulonefrite/patologia , Rim/patologia , Glomérulos Renais/patologia
5.
Nanomedicine ; 28: 102184, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32222475

RESUMO

Many nanomedicine approaches are struggling to reach high enough effectiveness in delivery if applied systemically. The perspective is sought to explore the clinical practices currently used for localized treatment. In this study, we combine in vivo targeting of carriers sensitive to the external magnetic field with clinically used endovascular delivery to specific site. Fluorescent micron-size capsules made of biodegradable polymers and containing magnetite nanoparticles incorporated in the capsule wall were explored in vivo using Near-Infrared Fluorescence Live Imaging for Real-Time. Comparison of systemic (intravenous) and directed (intra-arterial) administration of the magnetic microcapsule targeting in the hindpaw vessels demonstrated that using femoral artery injection in combination with magnetic field exposure is 4 times more efficient than tail vein injection. Thus, endovascular targeting significantly improves the capabilities of nanoengineered drug delivery systems reducing the systemic side effects of therapy.


Assuntos
Nanopartículas de Magnetita/química , Nanomedicina/métodos , Animais , Cápsulas/química , Sistemas de Liberação de Medicamentos/métodos , Humanos , Polímeros/química
6.
Soft Matter ; 14(44): 9012-9019, 2018 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-30378616

RESUMO

Carbon dots (CDs) are usually used as an alternative to other fluorescent nanoparticles. Apart from fluorescence, CDs also have other important properties for use in composite materials, first of all their ability to absorb light energy and convert it into heat. In our work, for the first time, CDs have been proposed as an alternative to gold nanostructures for harvesting light energy, which results in the opening of polymer-based containers with biologically active compounds. In this paper, we propose a method for the synthesis of polylactic acid microchamber arrays with embedded CDs. A comparative analysis was made of the damage to microchambers functionalized with gold nanorods and with CD aggregates, depending on the wavelength and power of the laser used. The release of fluorescent cargo from the microchamber arrays with CD aggregates under laser exposure was demonstrated.

7.
Nanomaterials (Basel) ; 14(14)2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39057891

RESUMO

Reliable cell labeling and tracking techniques are imperative for elucidating the intricate and ambiguous interactions between mesenchymal stromal cells (MSCs) and tumors. Here, we explore fluorescent photoconvertible nanoengineered vesicles to study mMSC migration in brain tumors. These 3 µm sized vesicles made of carbon nanoparticles, Rhodamine B (RhB), and polyelectrolytes are readily internalized by cells. The dye undergoes photoconversion under 561 nm laser exposure with a fluorescence blue shift upon demand. The optimal laser irradiation duration for photoconversion was 0.4 ms, which provided a maximal blue shift of the fluorescent signal label without excessive laser exposure on cells. Vesicles modified with an extra polymer layer demonstrated enhanced intracellular uptake without remarkable effects on cell viability, motility, or proliferation. The optimal ratio of 20 vesicles per mMSC was determined. Moreover, the migration of individual mMSCs within 2D and 3D glioblastoma cell (EPNT-5) colonies over 2 days and in vivo tumor settings over 7 days were traced. Our study provides a robust nanocomposite platform for investigating MSC-tumor dynamics and offers insights into envisaged therapeutic strategies. Photoconvertible vesicles also present an indispensable tool for studying complex fundamental processes of cell-cell interactions for a wide range of problems in biomedicine.

8.
Heliyon ; 10(10): e30680, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38813172

RESUMO

Tracing individual cell pathways among the whole population is crucial for understanding their behavior, cell communication, migration dynamics, and fate. Optical labeling is one approach for tracing individual cells, but it typically requires genetic modification to induce the generation of photoconvertible proteins. Nevertheless, this approach has limitations and is not applicable to certain cell types. For instance, genetic modification often leads to the death of macrophages. This study aims to develop an alternative method for labeling macrophages by utilizing photoconvertible micron-sized capsules capable of easy internalization and prolonged retention within cells. Thermal treatment in a polyvinyl alcohol gel medium is employed for the scalable synthesis of capsules with a wide range of fluorescent dyes, including rhodamine 6G, pyronin B, fluorescein, acridine yellow, acridine orange, thiazine red, and previously reported rhodamine B. The fluorescence brightness, photostability, and photoconversion ability of the capsules are evaluated using confocal laser scanning microscopy. Viability, uptake, mobility, and photoconversion studies are conducted on RAW 264.7 and bone marrow-derived macrophages, serving as model cell lines. The production yield of the capsules is increased due to the use of polyvinyl alcohol gel, eliminating the need for conventional filtration steps. Capsules entrapping rhodamine B and rhodamine 6G meet all requirements for intracellular use in individual cell tracking. Mass spectrometry analysis reveals a sequence of deethylation steps that result in blue shifts in the dye spectra upon irradiation. Cellular studies on macrophages demonstrate robust uptake of the capsules. The capsules exhibit minimal cytotoxicity and have a negligible impact on cell motility. The successful photoconversion of RhB-containing capsules within cells highlights their potential as alternatives to photoconvertible proteins for individual cell labeling, with promising applications in personalized medicine.

9.
Biomater Adv ; 158: 213759, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38227987

RESUMO

While microbubbles (MB) are routinely used for ultrasound (US) imaging, magnetic MB are increasingly explored as they can be guided to specific sites of interest by applied magnetic field gradient. This requires the MB shell composition tuning to prolong MB stability and provide functionalization capabilities with magnetic nanoparticles. Hence, we developed air-filled MB stabilized by a protein-polymer complex of bovine serum albumin (BSA) and poly-L-arginine (pArg) of different molecular weights, showing that pArg of moderate molecular weight distribution (15-70 kDa) enabled MB with greater stability and acoustic response while preserving MB narrow diameters and the relative viability of THP-1 cells after 48 h of incubation. After MB functionalization with superparamagnetic iron oxide nanoparticles (SPION), magnetic moment values provided by single MB confirmed the sufficient SPION deposition onto BSA + pArg MB shells. During MB magnetic navigation in a blood vessel mimicking phantom with magnetic tweezers and in a Petri dish with adherent mouse renal carcinoma cell line, we demonstrated the effectiveness of magnetic MB localization in the desired area by magnetic field gradient. Magnetic MB co-localization with cells was further exploited for effective doxorubicin delivery with drug-loaded MB. Taken together, these findings open new avenues in control over albumin MB properties and magnetic navigation of SPION-loaded MB, which can envisage their applications in diagnostic and therapeutic needs.


Assuntos
Nanopartículas de Magnetita , Peptídeos , Camundongos , Animais , Nanopartículas de Magnetita/uso terapêutico , Microbolhas , Soroalbumina Bovina , Nanopartículas Magnéticas de Óxido de Ferro
10.
ACS Appl Mater Interfaces ; 15(21): 25354-25368, 2023 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-37204221

RESUMO

The intravesical instillation procedure is a proven method in modern urology for the treatment of bladder diseases. However, the low therapeutic efficiency and painfulness of the instillation procedure are significant limitations of this method. In the present study, we propose an approach to solving this problem by using microsized mucoadhesive macromolecular carriers based on whey protein isolate with the possibility of prolonged release of drugs as a drug delivery system. The optimal water-to-oil ratio (1:3) and whey protein isolate concentration (5%) were determined to obtain emulsion microgels with sufficient loading efficiency and mucoadhesive properties. The droplet diameter of emulsion microgels varies from 2.2 to 3.8 µm. The drug release kinetics from the emulsion microgels was evaluated. The release of the model dye in saline and artificial urine in vitro was observed for 96 h and reached up to 70% of loaded cargo for samples. The effect of emulsion microgels on the morphology and viability of two cell lines was observed: L929 mouse fibroblasts (normal adherent cells) and THP-1 human monocytes (cancer suspension cells). Developed emulsion microgels (5%, 1:3 and 1:5) showed sufficient mucoadhesion to a porcine bladder urothelium ex vivo. The biodistribution of emulsion microgels (5%, 1:3 and 1:5) in mice (n = 3) after intravesical (instillation) and systemic (intravenous) administration was assessed in vivo and ex vivo using near-infrared fluorescence live imaging for real time. It was demonstrated that intravesical instillation allows approximately 10 times more efficient accumulation of emulsion microgels in the mice urinary bladder in vivo 1 h after injection compared to systemic injection. The retention of the emulsion of mucoadhesive microgels in bladders after the intravesical instillation was observed for 24 h.


Assuntos
Microgéis , Neoplasias da Bexiga Urinária , Camundongos , Humanos , Animais , Suínos , Distribuição Tecidual , Urotélio/metabolismo , Emulsões/farmacologia , Proteínas do Soro do Leite/metabolismo , Proteínas do Soro do Leite/farmacologia , Proteínas do Soro do Leite/uso terapêutico , Sistemas de Liberação de Medicamentos
11.
Pharmaceutics ; 14(10)2022 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-36297579

RESUMO

In a modern high-tech medicine, drug-eluting polymer coatings are actively used to solve a wide range of problems, including the prevention of post-surgery infection, inflammatory, restenosis, thrombosis and many other implant-associated complications. For major assumptions, the drug elution mechanism is considered mainly to be driven by the degradation of the polymer matrix. This process is very environmentally dependent, unpredictable and often leads to a non-linear drug release kinetic. In the present work, we demonstrate how the laser microperforation of cargo-loaded biodegradable films could be used as a tool to achieve zero-order release kinetics with different elution rates. The effects of the laser-induced hole's diameter (10, 18, 22, 24 µm) and their density (0, 1, 2, 4 per sample) on release kinetic are studied. The linear dynamics of elution was measured for all perforation densities. Release rates were estimated to be 0.018 ± 0.01 µg/day, 0.211 ± 0.08 µg/day, 0.681 ± 0.1 µg/day and 1.19 ± 0.12 µg/day for groups with 0, 1, 2, 4 microperforations, respectively. The role of biodegradation of the polymer matrix is reduced only to the decomposition of the film over time with no major influence on elution rates.

12.
Polymers (Basel) ; 14(20)2022 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-36297899

RESUMO

Drug-eluting films made of bioresorbable polymers are a widely used tool of modern personalized medicine. However, most currently existing methods of producing coatings do not go beyond the laboratory, as they have low encapsulation efficiency and/or difficulties in scaling up. The PLACE (Printed Layered Adjustable Cargo Encapsulation) technology proposed in this article uses an additive approach for film manufacturing. PLACE technology is accessible, scalable, and reproducible in any laboratory. As a demonstration of the technology capabilities, we fabricated layered drug-eluting polyglycolic acid films containing different concentrations of Cefazolin antibiotic. The influence of the amount of loaded drug component on the film production process and the release kinetics was studied. The specific loading of drugs was significantly increased to 200-400 µg/cm2 while maintaining the uniform release of Cefazolin antibiotic in a dosage sufficient for local antimicrobial therapy for 14 days. The fact that the further increase in the drug amount results in the crystallization of a substance, which can lead to specific defects in the cover film formation and accelerated one-week cargo release, was also shown, and options for further technology development were proposed.

13.
Pharmaceutics ; 14(6)2022 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-35745772

RESUMO

Infectious sequelae caused by surgery are a significant problem in modern medicine due to their reduction of therapeutic effectiveness and the patients' quality of life.Recently, new methods of local antimicrobial prophylaxis of postoperative sequelae have been actively developed. They allow high local concentrations of drugs to be achieved, increasing the antibiotic therapy's effectiveness while reducing its side effects. We have developed and characterized antimicrobial hydrogels based on an inexpensive and biocompatible natural substance from the dairy industry-whey protein isolate-as matrices for drug delivery. The release of cefazolin from the pores of hydrogel structures directly depends on the amount of the loaded drug and occurs in a prolonged manner for three days. Simultaneously with the antibiotic release, hydrogel swelling and partial degradation occurs. The WPI hydrogels absorb solvent, doubling in size in three days and retaining cefazolin throughout the duration of the experiment. The antimicrobial activity of cefazolin-loaded WPI hydrogels against Staphylococcus aureus growth is prolonged in comparison to that of the free cefazolin. The overall cytotoxic effect of cefazolin-containing WPI hydrogels is lower than that of free antibiotics. Thus, our work shows that antimicrobial WPI hydrogels are suitable candidates for local antibiotic therapy of infectious surgical sequelae.

14.
Pharmaceutics ; 14(5)2022 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-35631642

RESUMO

The problem of reducing the side effects associated with drug distribution throughout the body in the treatment of various kidney diseases can be solved by effective targeted drug delivery. The method described herein involves injection of a drug encapsulated in polyelectrolyte capsules to achieve prolonged local release and long-term capillary retention of several hours while these capsules are administered via the renal artery. The proposed method does not imply disruption (puncture) of the renal artery or aorta and is suitable for long-term chronic experiments on mice. In this study, we compared how capsule size and dosage affect the target kidney blood flow. It has been established that an increase in the diameter of microcapsules by 29% (from 3.1 to 4.0 µm) requires a decrease in their concentration by at least 50% with the same suspension volume. The photoacoustic method, along with laser speckle contrast imaging, was shown to be useful for monitoring blood flow and selecting a safe dose. Capsules contribute to a longer retention of a macromolecular substance in the target kidney compared to its free form due to mechanical retention in capillaries and slow impregnation into surrounding tissues during the first 1-3 h, which was shown by fluorescence tomography and microscopy. At the same time, the ability of capillaries to perform almost complete "self-cleaning" from capsular shells during the first 12 h leads to the preservation of organ tissues in a normal state. The proposed strategy, which combines endovascular surgery and the injection of polymer microcapsules containing the active substance, can be successfully used to treat a wide range of nephropathies.

15.
ACS Appl Mater Interfaces ; 14(46): 51579-51592, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36367877

RESUMO

A new promising trend in personalized medicine is the use of autologous cells (macrophages or stem cells) for cell-based therapy and also as a "Trojan horse" for targeted delivery of a drug carrier. The natural ability of macrophages for chemotaxis allows them to deliver cargo to the damaged area, significantly reducing side effects on healthy organ tissues. Therefore, it is important to develop tools to track their behavior in the organism. While labeled containers can serve as anchored tags for imaging macrophages in vivo, they can affect the properties and functions of macrophages. This work demonstrates that 3 µm sized capsules based on biocompatible polyelectrolytes and fluorescently labeled with both Cy7 and RITC dyes do not affect cell functionalization in vitro, such as viability, proliferation, and movement of transformed monocyte/macrophage-like cells (RAW 264.7) and primary bone marrow derived macrophages (BMDM) at maximal loading of five capsules per cell. In addition, capsules allowed fluorescent detection of ex vivo loaded cells 24 h after the tail vein injection in vivo and visualization of microcapsule-laden macrophages ex vivo using confocal microscopy. We have delivered about 62.5% of injected BMDM containing 12.5 million capsules with 3.75 µg of high-molecular-weight cargo (0.3 pg/capsule) to the liver. Our results demonstrate that 3 µm polyelectrolyte fluorescently labeled microcapsules can be used for safe macrophage loading, allowing cell tracking and drug delivery, which will facilitate development of macrophage-based cell therapy protocols.


Assuntos
Portadores de Fármacos , Sistemas de Liberação de Medicamentos , Cápsulas , Macrófagos , Rastreamento de Células
16.
Pharmaceutics ; 14(10)2022 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-36297621

RESUMO

Bladder neck contracture (BNC) is a complication of the surgical treatment of benign and malignant prostate conditions and is associated with the partial or complete blockage of urination. Correction of this condition usually requires repeated surgical intervention, which does not guarantee recovery. Balloon dilation is a minimally invasive alternative to the surgical dissection of tissues; however, it significantly reduces the patient's quality of life. Additional local anti-inflammatory treatment may reduce the number of procedures requested and increase the attractiveness of this therapeutic strategy. Here, we report about an ultrathin biocompatible coating based on polylactic acid for Foley catheter balloons that can provide localized release of Prednol-L in the range of 56-99 µg in the BNC zone under conventional diagnostic ultrasound exposure. Note that the exposure of a transrectal probe with a conventional gray-scale ultrasound regimen with and without shear wave elastography (SWE) was comparably effective for Prednol-L release from the coating surface of a Foley catheter balloon. This strategy does not require additional manipulations by clinicians. The trigger for the drug release is the ultrasound exposure, which is applied for visualization of the balloon's location during the dilation process. In vivo experiments demonstrated the absence of negative effects of the usage of a coated Foley catheter for balloon dilation of the bladder neck and urethra.

17.
ACS Appl Bio Mater ; 5(7): 3338-3348, 2022 07 18.
Artigo em Inglês | MEDLINE | ID: mdl-35791763

RESUMO

Microbubbles are routinely used ultrasound contrast agents in the clinic. While a soft protein shell is commercially preferable for imaging purposes, a rigid polymer shell demonstrates prolonged agent stability. Hence, combining polymers and proteins in one shell composition can advance microbubble properties. We formulated the hybrid "protein-copolymer" microbubble shell with a complex of bovine serum albumin and an amphiphilic copolymer of N-vinyl-2-pyrrolidone and acrylic acid. The resulting microbubbles demonstrated advanced physicochemical and acoustic properties, preserving in vitro biocompatibility. Adjusting the mass ratio between protein and copolymer allowed fine tuning of the microbubble properties of concentration (by two orders, up to 1010 MBs/mL), mean size (from 0.8 to 5 µm), and shell thickness (from 28 to 50 nm). In addition, the minimum air-liquid surface tension for the "protein-copolymer" solution enabled the highest bubble concentration. At the same time, a higher copolymer amount in the bubble shell increased the bubble size and tuned duration and intensity of the contrast during an ultrasound procedure. Demonstrated results exemplify the potential of the hybrid "protein-polymer" microbubble shell, allowing tailoring of microbubble properties for image-guided applications, combining advances of each material involved in the formulation.


Assuntos
Meios de Contraste , Microbolhas , Acrilatos , Resinas Acrílicas , Meios de Contraste/química , Polímeros/química , Povidona/análogos & derivados , Soroalbumina Bovina
18.
Colloids Surf B Biointerfaces ; 219: 112856, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36150237

RESUMO

Gas-liquid interfaces are reaching a particular interest in biomedicine. Microbubbles, ultrasound contrast agents of clinical routine, gained increasing attention as theranostic platforms due to the preserved acoustic response, drug conjugation capabilities, and applicability in biological barrier opening. A combination of microbubbles and photodynamic therapy agents can enhance the photodynamic effect, yet the evaluation of agent conjugation on microbubble stabilization and photodynamic effect is needed. Hence, two commercially available phthalocyanine photosensitizers - Holosens® (ZnPc) and Photosens® (AlPc) - were coupled with bovine serum albumin before microbubble synthesis. We demonstrated an albumin: phthalocyanine ratio of 1:1 and covalent attachment for ZnPc, a ratio of 1:3 with electrostatic binding for AlPc. Submicron-sized microbubbles (air- and SF6- filled) had a diameter of 0.8 µm. Albumin-phthalocyanine conjugates increased the microbubble concentration and shelf-life stability compared to plain ones. We hypothesized that phthalocyanine fluorescence lifetime values decreased after conjugation with microbubbles due to narrow distance between conjugates in the shell. Agents based on AlPc demonstrated higher photodynamic activity than agents based on ZnPc, and microbubbles preserved acoustic stability in human blood plasma. The biodistribution of AlPc-conjugated microbubbles was evaluated. We conclude that our microbubble platforms demonstrate greater photodynamic activity and prolonged stability for further applications in photodynamic therapy.

19.
Materials (Basel) ; 14(4)2021 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-33562870

RESUMO

A novel versatile biocompatible hydrogel of whey protein isolate (WPI) and two types of tannic acid (TAs) was prepared by crosslinking of WPI with TAs in a one-step method at high temperature for 30 min. WPI is one common protein-based preparation which is used for hydrogel formation. The obtained WPI-TA hydrogels were in disc form and retained their integrity after sterilization by autoclaving. Two TA preparations of differing molecular weight and chemical structure were compared, namely a polygalloyl glucose-rich extract-ALSOK 02-and a polygalloyl quinic acid-rich extract-ALSOK 04. Hydrogel formation was observed for WPI solutions containing both preparations. The swelling characteristics of hydrogels were investigated at room temperature at different pH values, namely 5, 7, and 9. The swelling ability of hydrogels was independent of the chemical structure of the added TAs. A trend of decrease of mass increase (MI) in hydrogels was observed with an increase in the TA/WPI ratio compared to the control WPI hydrogel without TA. This dependence (a MI decrease-TA/WPI ratio) was observed for hydrogels with different types of TA both in neutral and acidic conditions (pH 5.7). Under alkaline conditions (pH 9), negative values of swelling were observed for all hydrogels with a high content of TAs and were accompanied by a significant release of TAs from the hydrogel network. Our studies have shown that the release of TA from hydrogels containing ALSOK04 is higher than from hydrogels containing ALSOK 02. Moreover, the addition of TAs, which display a strong anti-cancer effect, increases the cytotoxicity of WPI-TAs hydrogels against the Hep-2 human laryngeal squamous carcinoma (Hep-2 cells) cell line. Thus, WPI-TA hydrogels with prolonged drug release properties and cytotoxicity effect can be used as anti-cancer scaffolds.

20.
Biomed Opt Express ; 12(7): 4467-4477, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34457426

RESUMO

Optical coherence tomography (OCT) has become widespread in clinical applications in which precise three-dimensional functional imaging of living organs is required. Nevertheless, the kidney is inaccessible for the high resolution OCT imaging due to a high light attenuation coefficient of skin and soft tissues that significantly limits the penetration depth of the probing laser beam. Here, we introduce a surgical protocol and fixation scheme that enables functional visualization of kidney's peritubular capillaries via OCT microangiography. The model of reversible/irreversible glomerulus embolization using drug microcarriers confirms the ability of OCT to detect circulatory disorders. This approach can be used for choosing optimal carriers, their dosages and diagnosis of other blood flow pathologies.

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