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1.
Biochem Biophys Res Commun ; 671: 124-131, 2023 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-37300942

RESUMO

BACKGROUND: In the surgical management of glioblastoma, a highly aggressive and incurable type of brain cancer, identification and treatment of residual tissue is the most common site of disease recurrence. Monitoring and localized treatment are achieved with engineered microbubbles (MBs) by combining ultrasound and fluorescence imaging with actively targeted temozolomide (TMZ) delivery. METHODS: The MBs were conjugated with a near-infrared fluorescence probe CF790, cyclic pentapeptide bearing the RGD sequence and a carboxyl-temozolomide, TMZA. The efficiency of adhesion to HUVEC cells was assessed in vitro in realistic physiological conditions of shear rate and vascular dimensions. Cytotoxicity of TMZA-loaded MBs on U87 MG cells and IC50 were assessed by MTT tests. RESULTS: We report on the design of injectable poly(vinyl alcohol) echogenic MBs designed as a platform with active targeting ability to tumor tissues, by tethering on the surface a ligand having the tripeptide sequence, RGD. The biorecognition of RGD-MBs onto HUVEC cells is quantitatively proved. Efficient NIR emission from the CF790-decorated MBs was successfully detected. The conjugation on the MBs surface of a specific drug as TMZ is achieved. The pharmacological activity of the coupled-to-surface drug is preserved by controlling the reaction conditions. CONCLUSIONS: We present an improved formulation of PVA-MBs to achieve a multifunctional device with adhesion ability, cytotoxicity on glioblastoma cells and supporting imaging.


Assuntos
Glioblastoma , Glioma , Humanos , Glioblastoma/tratamento farmacológico , Temozolomida/uso terapêutico , Medicina de Precisão , Linhagem Celular Tumoral , Recidiva Local de Neoplasia , Glioma/terapia , Glioma/tratamento farmacológico , Imagem Óptica , Oligopeptídeos/uso terapêutico , Microbolhas
2.
Langmuir ; 35(31): 10116-10127, 2019 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-31042396

RESUMO

Phase change contrast agents for ultrasound (US) imaging consist of nanodroplets (NDs) with a perfluorocarbon (PFC) liquid core stabilized with a lipid or a polymer shell. Liquid ↔ gas transition, occurring in the core, can be triggered by US to produce acoustically active microbubbles (MBs) in a process named acoustic droplet vaporization (ADV). MB shells containing polymerized diacetylene moiety were considered as a good trade off between the lipid MBs, showing optimal attenuation, and the polymeric ones, displaying enhanced stability. This work reports on novel perfluoropentane and perfluorobutane NDs stabilized with a monolayer of an amphiphilic fatty acid, i.e. 10,12-pentacosadiynoic acid (PCDA), cured with ultraviolet (UV) irradiation. The photopolymerization of the diacetylene groups, evidenced by the appearance of a blue color due to the conjugation of ene-yne sequences, exhibits a chromatic transition from the nonfluorescent blue color to a fluorescent red color when the NDs are heated or the pH of the suspension is basic. An estimate of the molecular weights reached by the polymerized PCDA in the shell, poly(PCDA), has been obtained using gel permeation chromatography and MALDI-TOF mass spectrometry. The poly(PCDA)/PFC NDs show good biocompatibility with fibroblast cells. ADV efficiency and acoustic properties before and after the transition were tested using a 1 MHz probe, revealing a resonance frequency between 1 and 2 MHz similar to other lipidic MBs. The surface of PCDA shelled NDs can be easily modified without influencing the stability and the acoustic performances of droplets. As a proof of concept we report on the conjugation of cyclic RGD and PEG chains of the particles to support targeting ability toward endothelial cells.

3.
Phys Chem Chem Phys ; 18(12): 8378-88, 2016 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-26931337

RESUMO

In this paper we report on the study of the interface of hybrid shell droplets encapsulating decafluoropentane (DFP), which exhibit interesting potentialities for ultrasound (US) imaging. The fabrication of the droplets is based on the deposition of a dextran methacrylate layer onto the surface of surfactants. The droplets have been stabilized against coalescence by UV curing, introducing crosslinks in the polymer layer and transforming the shell into an elastomeric membrane with a thickness of about 300 nm with viscoelastic behaviour. US irradiation induces the evaporation of the DFP core of the droplets transforming the particles into microbubbles (MBs). The presence of a robust crosslinked polymer shell introduces an unusual stability of the droplets also during the core phase transition and allows the recovery of the initial droplet state after a few minutes from switching off US. The interfacial tension of the droplets has been investigated by two approaches, the pendant drop method and an indirect method, based on the determination of the liquid ↔ gas transition point of DFP confined in the droplet core. The re-condensation process has been followed by capturing images of single MBs by confocal microscopy. The time evolution of MB relaxation to droplets was analysed in terms of a modified Church model to account for the structural complexity of the MB shell, i.e. a crosslinked polymer layer over a layer of surfactants. In this way the microrheology parameters of the shell were determined. In a previous paper (Chem. Commun., 2013, 49, 5763-5765) we showed that these systems could be used as ultrasound contrast agents (UCAs). In this work we substantiate this view assessing some key features offered by the viscoelastic nature of the droplet shell.


Assuntos
Meios de Contraste/química , Materiais Biocompatíveis/química , Varredura Diferencial de Calorimetria , Dextranos/química , Difusão Dinâmica da Luz , Microbolhas , Microscopia de Força Atômica , Microscopia Confocal , Polímeros/química , Tensão Superficial , Tensoativos/química , Termogravimetria , Ultrassonografia
4.
Biomacromolecules ; 16(6): 1753-60, 2015 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-25923337

RESUMO

Drugs can be delivered by a temperature change-driven shrinking of the nanocarrier followed by the cargo release. This paper describes a different structural response to temperature, performed by nanoparticles of poly(N-isopropylacrylamide) and hyaluronic acid. Around 35 °C, the hydrophobicity of the vinyl polymer drives a core-shell rearrangement with the acrylamide chains confined in the core and the polysaccharide moiety forming the shell. In this arrangement, the nanoparticles enable the active targeting of tumor cells, due to the specific interaction of hyaluronic acid with the CD44 receptors. When doxorubicin-loaded nanoparticles are up-taken, the polysaccharide part degrades in the cytoplasm and the cytotoxic effect of the anticancer drug in colon adenocarcinoma cells has a 2-fold increase with respect to healthy fibroblasts. These core-shell particles have hyaluronic acid as the key factor for the specific targeting of tumor cells and drug release with poly(N-isopropylacrylamide) driving the transition.


Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Doxorrubicina/administração & dosagem , Nanopartículas/química , Temperatura , Resinas Acrílicas/química , Animais , Antibióticos Antineoplásicos/química , Doxorrubicina/química , Células HT29 , Humanos , Receptores de Hialuronatos/metabolismo , Ácido Hialurônico/administração & dosagem , Camundongos , Células NIH 3T3 , Ligação Proteica
5.
Soft Matter ; 10(1): 214-26, 2014 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-24651844

RESUMO

Polymer-shelled magnetic microbubbles have great potential as hybrid contrast agents for ultrasound and magnetic resonance imaging. In this work, we studied US/MRI contrast agents based on air-filled poly(vinyl alcohol)-shelled microbubbles combined with superparamagnetic iron oxide nanoparticles (SPIONs). The SPIONs are integrated either physically or chemically into the polymeric shell of the microbubbles (MBs). As a result, two different designs of a hybrid contrast agent are obtained. With the physical approach, SPIONs are embedded inside the polymeric shell and with the chemical approach SPIONs are covalently linked to the shell surface. The structural design of hybrid probes is important, because it strongly determines the contrast agent's response in the considered imaging methods. In particular, we were interested how structural differences affect the shell's mechanical properties, which play a key role for the MBs' US imaging performance. Therefore, we thoroughly characterized the MBs' geometric features and investigated low-frequency mechanics by using atomic force microscopy (AFM) and high-frequency mechanics by using acoustic tests. Thus, we were able to quantify the impact of the used SPIONs integration method on the shell's elastic modulus, shear modulus and shear viscosity. In summary, the suggested approach contributes to an improved understanding of structure-property relations in US-active hybrid contrast agents and thus provides the basis for their sustainable development and optimization.

6.
Cardiovasc Ultrasound ; 12: 24, 2014 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-24993845

RESUMO

BACKGROUND: A novel polymer-shelled contrast agent (CA) with multimodal and target-specific potential was developed recently. To determine its ultrasonic diagnostic features, we evaluated the endocardial border delineation as visualized in a porcine model and the concomitant effect on physiological variables. METHODS: Three doses of the novel polymer-shelled CA (1.5 ml, 3 ml, and 5 ml [5 × 10(8) microbubbles (MBs)/ml]) and the commercially available CA SonoVue (1.5 ml [2-5 × 10(8) MBs/ml]) were used. Visual evaluations of ultrasound images of the left ventricle were independently performed by three observers who graded each segment in a 6-segment model as either 0 = not visible, 1 = weakly visible, or 2 = visible. Moreover, the duration of clinically useful contrast enhancement and the left ventricular opacification were determined. During anesthesia, oxygen saturation, heart rate, and arterial pressure were sampled every minute and the effect of injection of CA on these physiological variables was evaluated. RESULTS: The highest dose of the polymer-shelled CA gave results comparable to SonoVue. Thus, no significant difference in the overall segment score distribution (2-47-95 vs. 1-39-104), time for clinically sufficient contrast enhancement (20-40 s for both) and left ventricular overall opacification was found. In contrast, when comparing the endocardial border delineation capacity for different regions SonoVue showed significantly higher segment scores for base and mid, except for the mid region when injecting 1.5 ml of the polymer-shelled CA. Neither high nor low doses of the polymer-shelled CA significantly affected the investigated physiological variables. CONCLUSIONS: This study demonstrated that the novel polymer-shelled CA can be used in contrast-enhanced diagnostic imaging without influence on major physiological variables.


Assuntos
Meios de Contraste , Ecocardiografia/métodos , Endocárdio/diagnóstico por imagem , Álcool de Polivinil , Animais , Feminino , Ventrículos do Coração/diagnóstico por imagem , Microbolhas , Modelos Animais , Sus scrofa
7.
Commun Chem ; 7(1): 83, 2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38609466

RESUMO

Characterization of biopolymers in both dry and weakly hydrated amorphous states has implications for the pharmaceutical industry since it provides understanding of the effect of lyophilisation on stability and biological activity. Atomistic Molecular Dynamics (MD) simulations probe structural and dynamical features related to system functionality. However, while simulations in homogenous aqueous environments are routine, dehydrated model assemblies are a challenge with systems investigated in-silico needing careful consideration; simulated systems potentially differing markedly despite seemingly negligible changes in procedure. Here we propose an in-silico protocol to model proteins in lyophilised and weakly hydrated amorphous states that is both more experimentally representative and routinely applicable. Since the outputs from MD align directly with those accessed by neutron scattering, the efficacy of the simulation protocol proposed is shown by validating against experimental neutron data for apoferritin and insulin. This work also highlights that without cooperative experimental and simulative data, development of simulative procedures using MD alone would prove most challenging.

8.
Pharmaceuticals (Basel) ; 17(5)2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38794199

RESUMO

Radiotherapy treatment plans have become highly conformal, posing additional constraints on the accuracy of treatment delivery. Here, we explore the use of radiation-sensitive ultrasound contrast agents (superheated phase-change nanodroplets) as dosimetric radiation sensors. In a series of experiments, we irradiated perfluorobutane nanodroplets dispersed in gel phantoms at various temperatures and assessed the radiation-induced nanodroplet vaporization events using offline or online ultrasound imaging. At 25 °C and 37 °C, the nanodroplet response was only present at higher photon energies (≥10 MV) and limited to <2 vaporization events per cm2 per Gy. A strong response (~2000 vaporizations per cm2 per Gy) was observed at 65 °C, suggesting radiation-induced nucleation of the droplet core at a sufficiently high degree of superheat. These results emphasize the need for alternative nanodroplet formulations, with a more volatile perfluorocarbon core, to enable in vivo photon dosimetry. The current nanodroplet formulation carries potential as an innovative gel dosimeter if an appropriate gel matrix can be found to ensure reproducibility. Eventually, the proposed technology might unlock unprecedented temporal and spatial resolution in image-based dosimetry, thanks to the combination of high-frame-rate ultrasound imaging and the detection of individual vaporization events, thereby addressing some of the burning challenges of new radiotherapy innovations.

9.
Cardiovasc Ultrasound ; 11: 33, 2013 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-23987142

RESUMO

BACKGROUND: A multimodal polymer-shelled contrast agent (CA) with target specific potential was recently developed and tested for its acoustic properties in a single element transducer setup. Since the developed polymeric CA has different chemical composition than the commercially available CAs, there is an interest to study its acoustic response when using clinical ultrasound systems. The aim of this study was therefore to investigate the acoustic response by studying the visualization capability and shadowing effect of three polymer-shelled CAs when using optimized sequences for contrast imaging. METHODS: The acoustic response of three types of the multimodal CA was evaluated in a tissue mimicking flow phantom setup by measuring contrast to tissue ratio (CTR) and acoustic shadowing using five image sequences optimized for contrast imaging. The measurements were performed over a mechanical index (MI) range of 0.2-1.2 at three CA concentrations (106, 105, 104 microbubbles/ml). RESULTS: The CTR-values were found to vary with the applied contrast sequence, MI and CA. The highest CTR-values were obtained when a contrast sequence optimized for higher MI imaging was used. At a CA concentration of 106 microbubbles/ml, acoustic shadowing was observed for all contrast sequences and CAs. CONCLUSIONS: The CAs showed the potential to enhance ultrasound images generated by available contrast sequences. A CA concentration of 106 MBs/ml implies a non-linear relation between MB concentration and image intensity.


Assuntos
Artérias Carótidas/diagnóstico por imagem , Meios de Contraste , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Microbolhas , Imagens de Fantasmas , Polímeros/química , Meios de Contraste/química , Dextranos/síntese química , Desenho de Equipamento , Humanos , Nanopartículas de Magnetita , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Ultrassonografia/instrumentação , Ultrassonografia/métodos
10.
Pharmaceutics ; 15(1)2023 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-36678846

RESUMO

This proof-of-concept study lays the foundations for the development of a delivery strategy for radioactive lanthanides, such as Yttrium-90, against recurrent glioblastoma. Our appealing hypothesis is that by taking advantage of the combination of biocompatible polyvinyl alcohol (PVA) microbubbles (MBs) and endovascular radiopharmaceutical infusion, a minimally invasive selective radioembolization can be achieved, which can lead to personalized treatments limiting off-target toxicities for the normal brain. The results show the successful formulation strategy that turns the ultrasound contrast PVA-shelled microbubbles into a microdevice, exhibiting good loading efficiency of Yttrium cargo by complexation with a bifunctional chelator. The selective targeting of Yttrium-loaded MBs on the glioblastoma-associated tumor endothelial cells can be unlocked by the biorecognition between the overexpressed αVß3 integrin and the ligand Cyclo(Arg-Gly-Asp-D-Phe-Lys) at the PVA microbubble surface. Hence, we show the suitability of PVA MBs as selective Y-microdevices for in situ injection via the smallest (i.e., 1.2F) neurointerventional microcatheter available on the market and the accumulation of PVA MBs on the HUVEC cell line model of integrin overexpression, thereby providing ~6 × 10-15 moles of Y90 per HUVEC cell. We further discuss the potential impact of using such versatile PVA MBs as a new therapeutic chance for treating glioblastoma multiforme recurrence.

11.
Gels ; 9(7)2023 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-37504388

RESUMO

One of the main issues in the cultural heritage field of restoration chemistry is the identification of greener and more effective methods for the wet cleaning of paper artefacts, which serve as witnesses to human history and custodians of cultural values. In this context, we propose a biocompatible method to perform wet cleaning on paper based on the use of 1 MHz ultrasound in combination with water-dispersed polyvinyl alcohol microbubbles (PVAMBs), followed by dabbing with PVA-based hydrogel. This method can be applied to both old and new papers. FTIR spectroscopy, X-ray diffraction, HPLC analysis, pH measurements and tensile tests were performed on paper samples, to assess the efficacy of the cleaning system. According to the results, ultrasound-activated PVAMB application allows for an efficient interaction with rough and porous cellulose paper profiles, promoting the removal of cellulose degradation byproducts, while the following hydrogel dabbing treatment guarantees the removal of cleaning materials residues. Moreover, the results also pointed out that after the treatment no thermal or mechanical damages had affected the paper. In conclusion, the readability of these kinds of artifacts can be improved without causing an alteration of their structural properties, while mitigating the risk of ink diffusion.

12.
Biomacromolecules ; 13(11): 3592-601, 2012 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-23082791

RESUMO

Chemoselective chemistry is one of the main synthetic strategies for the design of bioactive constructs. In this contribution we report on the fabrication of core-shell microgel particles, obtained by "click chemistry" and "inverse emulsion droplets" techniques. Azido and alkyne derivatives of poly(vinyl alcohol) (PVA) in a 1:2 mol ratio of functional groups, respectively, were crosslinked by click chemistry method. The microgel particles were spherical in shape with an average diameter of about 2 µm and with a narrow size distribution. Residual unreacted alkyne groups present on the particle surface were "clicked" with an azido-grafted hyaluronic acid. These microgel particles with a PVA core and a hyaluronic acid shell were tested for bioorthogonality, that is, for the absence of cytotoxicity in the presence of unreacted clickable functionalities and demonstrated a remarkable ability to target adenocarcinoma colon cells (HT- 29) as well as to release locally the antitumor drug, doxorubicin. Internalization process was studied in connection with the presence of hyaluronic acid on the microgel particles surface. In this paper we introduce a concept device based on chemoselective chemistry, which may contribute to the design of micro- and nanoplatforms having controlled and multifunctional structures.


Assuntos
Neoplasias do Colo/tratamento farmacológico , Doxorrubicina/administração & dosagem , Sistemas de Liberação de Medicamentos , Ácido Hialurônico/química , Álcool de Polivinil/química , Adenocarcinoma/tratamento farmacológico , Transporte Biológico , Linhagem Celular Tumoral , Doxorrubicina/metabolismo , Doxorrubicina/farmacologia , Géis/química , Humanos , Mitocôndrias/efeitos dos fármacos , Tamanho da Partícula , Polímeros/química
13.
Biomacromolecules ; 13(5): 1390-9, 2012 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-22458325

RESUMO

Microbubbles (MBs) are commonly used as injectable ultrasound contrast agent (UCA) in modern ultrasonography. Polymer-shelled UCAs present additional potentialities with respect to marketed lipid-shelled UCAs. They are more robust; that is, they have longer shelf and circulation life, and surface modifications are quite easily accomplished to obtain enhanced targeting and local drug delivery. The next generation of UCAs will be required to support not only ultrasound-based imaging methods but also other complementary diagnostic approaches such as magnetic resonance imaging or computer tomography. This work addresses the features of MBs that could function as contrast agents for both ultrasound and magnetic resonance imaging. The results indicate that the introduction of iron oxide nanoparticles (SPIONs) in the poly(vinyl alcohol) shell or on the external surface of the MBs does not greatly decrease the echogenicity of the host MBs compared with the unmodified one. The presence of SPIONs provides enough magnetic susceptibility to the MBs to accomplish good detectability both in vitro and in vivo. The distribution of SPIONs on the shell and their aggregation state seem to be key factors for the optimization of the transverse relaxation rate.


Assuntos
Meios de Contraste , Imageamento por Ressonância Magnética , Nanopartículas de Magnetita , Microbolhas , Tomografia Computadorizada por Raios X , Meios de Contraste/química , Imageamento por Ressonância Magnética/instrumentação , Nanopartículas de Magnetita/química , Tamanho da Partícula , Tomografia Computadorizada por Raios X/instrumentação
14.
Sci Rep ; 12(1): 8012, 2022 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-35568710

RESUMO

Methods allowing for in situ dosimetry and range verification are essential in radiotherapy to reduce the safety margins required to account for uncertainties introduced in the entire treatment workflow. This study suggests a non-invasive dosimetry concept for carbon ion radiotherapy based on phase-change ultrasound contrast agents. Injectable nanodroplets made of a metastable perfluorobutane (PFB) liquid core, stabilized with a crosslinked poly(vinylalcohol) shell, are vaporized at physiological temperature when exposed to carbon ion radiation (C-ions), converting them into echogenic microbubbles. Nanodroplets, embedded in tissue-mimicking phantoms, are exposed at 37 °C to a 312 MeV/u clinical C-ions beam at different doses between 0.1 and 4 Gy. The evaluation of the contrast enhancement from ultrasound imaging of the phantoms, pre- and post-irradiation, reveals a significant radiation-triggered nanodroplets vaporization occurring at the C-ions Bragg peak with sub-millimeter shift reproducibility and dose dependency. The specific response of the nanodroplets to C-ions is further confirmed by varying the phantom position, the beam range, and by performing spread-out Bragg peak irradiation. The nanodroplets' response to C-ions is influenced by their concentration and is dose rate independent. These early findings show the ground-breaking potential of polymer-shelled PFB nanodroplets to enable in vivo carbon ion dosimetry and range verification.


Assuntos
Carbono , Polímeros , Íons , Reprodutibilidade dos Testes , Ultrassonografia
15.
Ultrasound Med Biol ; 48(1): 149-156, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34629191

RESUMO

The potential of proton therapy to improve the conformity of the delivered dose to the tumor volume is currently limited by range uncertainties. Injectable superheated nanodroplets have recently been proposed for ultrasound-based in vivo range verification, as these vaporize into echogenic microbubbles on proton irradiation. In previous studies, offline ultrasound images of phantoms with dispersed nanodroplets were acquired after irradiation, relating the induced vaporization profiles to the proton range. However, the aforementioned method did not enable the counting of individual vaporization events, and offline imaging cannot provide real-time feedback. In this study, we overcame these limitations using high-frame-rate ultrasound imaging with a linear array during proton irradiation of phantoms with dispersed perfluorobutane nanodroplets at 37°C and 50°C. Differential image analysis of subsequent frames allowed us to count individual vaporization events and to localize them with a resolution beyond the ultrasound diffraction limit, enabling spatial and temporal quantification of the interaction between ionizing radiation and nanodroplets. Vaporization maps were found to accurately correlate with the stopping distribution of protons (at 50°C) or secondary particles (at both temperatures). Furthermore, a linear relationship between the vaporization count and the number of incoming protons was observed. These results indicate the potential of real-time high-frame-rate contrast-enhanced ultrasound imaging for proton range verification and dosimetry.


Assuntos
Microbolhas , Prótons , Imagens de Fantasmas , Ultrassonografia , Volatilização
16.
Bioconjug Chem ; 22(6): 1066-72, 2011 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-21545180

RESUMO

Poly(vinyl alcohol) microcapsules have been tailored as carriers to deliver camptothecin, an anticancer drug poorly soluble in water. The capsules have been reacted with a chitosan--folate complex in order to selectively target cancer cells overexpressing the folic acid receptor. Microcapsules decorated with the chitosan--folate complex have been characterized in their uptake and release of camptothecin, following the absorption band at λ = 370 nm diagnostic of the drug molecule. The selectivity of chitosan-folate microcapsules in targeting cancer cells has been demonstrated by fluorescence microscopy using HeLa cells, overexpressing the folate receptor and NIH3t3 fibroblasts as a negative control. The chitosan--folate microcapsules loaded with camptothecin significantly reduce the proliferation of HeLa tumor cells, while they have a negligible effect on fibroblasts. This work demonstrates that the chitosan--folate microcapsules represent a promising system to selectively target hydrophobic drugs, such as camptothecin, to tumor cells.


Assuntos
Camptotecina/metabolismo , Cápsulas/química , Quitosana/química , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos , Ácido Fólico/química , Adsorção , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Camptotecina/administração & dosagem , Camptotecina/química , Camptotecina/farmacologia , Proliferação de Células/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Células HeLa , Humanos , Camundongos , Estrutura Molecular , Células NIH 3T3 , Relação Estrutura-Atividade , Propriedades de Superfície , Células Tumorais Cultivadas
17.
Biomacromolecules ; 12(3): 593-601, 2011 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-21235225

RESUMO

Targeting is a main feature supporting any controlled drug delivery modality. Recently we developed poly(vinyl alcohol), PVA, based microbubbles as a potential new ultrasound contrast agent featuring an efficient ultrasound backscattering and a good shelf stability. The chemical versatility of the polymeric surface of this device offers a vast variety of coupling modalities useful for coating and specific targeting. We have designed a conjugation strategy on PVA shelled microbubbles to enable the localization and the drug delivery on tumor cells by modifying the surface of this polymeric ultrasound contrast agent (UCA) with oxidized hyaluronic acid (HAox). After the conversion of the microbubbles into microcapsules, the kinetics of the release of doxorubicin, a well-known antitumor drug, from uncoated and HAox-coated PVA microbubbles and microcapsules was investigated. Cytocompatibility and bioadhesive properties of the HA-modified microparticles were then tested on the HT-29 tumor cell line. Cytotoxicity to HT-29 tumor cells of microcapsules after loading with doxorubicin was studied, evidencing the efficacy of the HAox coating for the delivery of the drug to cells. These features are a prerequisite for a theranostic, that is, diagnostic and therapeutic, use of polymer-based UCAs.


Assuntos
Cápsulas/química , Doxorrubicina/administração & dosagem , Sistemas de Liberação de Medicamentos/métodos , Álcool de Polivinil/uso terapêutico , Antineoplásicos , Linhagem Celular Tumoral , Humanos , Ácido Hialurônico , Cinética , Neoplasias/tratamento farmacológico
18.
J Vis Exp ; (169)2021 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-33779605

RESUMO

Significant improvement of phase-change perfluorocarbon microdroplets (MDs) in the vast theranostic scenario passes through the optimization of the MDs composition with respect to synthesis efficiency, stability, and drug delivery capability. To this aim, decafluoropentane (DFP) MDs stabilized by a shell of dimethyldioctadecylammonium bromide (DDAB) cationic surfactant were designed. A high concentration of DDAB-MDs was readily obtained within a few seconds by pulsed high-power insonation, resulting in low polydisperse 1 µm size droplets. Highly positive ζ-potential, together with a long, saturated hydrocarbon chains of the DDAB shell, are key factors to stabilize the droplet and the drug cargo therein. The high affinity of the DDAB shell with cell plasma membrane allows for localized chemotherapeutics delivery by increasing the drug concentration at the tumor cell interface and boosting the uptake. This would turn DDAB-MDs into a relevant drug delivery tool exhibiting high antitumor activity at very low drug doses. In this work, the efficacy of such an approach is shown to dramatically improve the effect of doxorubicin against 3D spheroids of mammalian tumor cells, MDA-MB-231. The use of three-dimensional (3D) cell cultures developed in the form of multicellular tumor spheroids (i.e., densely packed cells in a spherical shape) has numerous advantages compared to 2D cell cultures: in addition to have the potential to bridge the gap between conventional in vitro studies and animal testing, it will improve the ability to perform more predictive in vitro screening assays for preclinical drug development or evaluate the potential of off-label drugs and new co-targeting strategies.


Assuntos
Técnicas de Cultura de Células/métodos , Sistemas de Liberação de Medicamentos/métodos , Compostos de Amônio Quaternário/metabolismo , Animais , Humanos
19.
Sci Rep ; 11(1): 19033, 2021 09 24.
Artigo em Inglês | MEDLINE | ID: mdl-34561481

RESUMO

Keratinocytes, the main cell type of the skin, are one of the most exposed cells to environmental factors, providing a first defence barrier for the host and actively participating in immune response. In fact, keratinocytes express pattern recognition receptors that interact with pathogen associated molecular patterns and damage associated molecular patterns, leading to the production of cytokines and chemokines, including interleukin (IL)-6. Herein, we investigated whether mechanical energy transported by low intensity ultrasound (US) could generate a mechanical stress able to induce the release of inflammatory cytokine such IL-6 in the human keratinocyte cell line, HaCaT. The extensive clinical application of US in both diagnosis and therapy suggests the need to better understand the related biological effects. Our results point out that US promotes the overexpression and secretion of IL-6, associated with the activation of nuclear factor-κB (NF-κB). Furthermore, we observed a reduced cell viability dependent on exposure parameters together with alterations in membrane permeability, paving the way for further investigating the molecular mechanisms related to US exposure.


Assuntos
Expressão Gênica/efeitos da radiação , Mediadores da Inflamação/metabolismo , Interleucina-6/metabolismo , Queratinócitos/metabolismo , Ondas Ultrassônicas/efeitos adversos , Permeabilidade da Membrana Celular/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Relação Dose-Resposta à Radiação , Células HaCaT , Humanos , Interleucina-6/genética , NF-kappa B/metabolismo , Estresse Mecânico
20.
Front Chem ; 9: 804893, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35174141

RESUMO

An easy and fast method to achieve chiral porphyrin films on glass is herein reported. The on-surface formation of organized supramolecular architectures with distinctive and remarkable chiroptical features strictly depends on the macrocycles used, the solvent chosen for the casting deposition, and most importantly, on the roughness of the glass slide. Dynamic light scattering studies performed on 10-4-10-6 M porphyrin solutions revealed the presence of small porphyrin aggregates, whose size and number increase depending on the initial concentration. Once transferred on surface, these protoaggregates act as nucleation seeds for the following, self-assembling into larger structures upon solvent evaporation, with a process driven by a fine balance between intermolecular and molecule-substrate interactions. The described method represents a straightforward way to fabricate porphyrin-based chiral surfaces onto a transparent and economic substrate in few minutes. The results obtained can be particularly promising for the development of sensors based on stereoselective optical active films, targeting the detection of chiral analytes of practical relevance, such as the so-called emerging pollutants released in the environment from agrochemical, food, and pharmaceutical manufacturing.

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