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1.
Proc Natl Acad Sci U S A ; 121(25): e2322403121, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38865273

RESUMO

Fluorine magnetic resonance imaging (19F-MRI) is particularly promising for biomedical applications owing to the absence of fluorine in most biological systems. However, its use has been limited by the lack of safe and water-soluble imaging agents with high fluorine contents and suitable relaxation properties. We report innovative 19F-MRI agents based on supramolecular dendrimers self-assembled by an amphiphilic dendrimer composed of a hydrophobic alkyl chain and a hydrophilic dendron. Specifically, this amphiphilic dendrimer bears multiple negatively charged terminals with high fluorine content, which effectively prevented intra- and intermolecular aggregation of fluorinated entities via electrostatic repulsion. This permitted high fluorine nuclei mobility alongside good water solubility with favorable relaxation properties for use in 19F-MRI. Importantly, the self-assembling 19F-MRI agent was able to encapsulate the near-infrared fluorescence (NIRF) agent DiR and the anticancer drug paclitaxel for multimodal 19F-MRI and NIRF imaging of and theranostics for pancreatic cancer, a deadly disease for which there remains no adequate early detection method or efficacious treatment. The 19F-MRI and multimodal 19F-MRI and NIRF imaging studies on human pancreatic cancer xenografts in mice confirmed the capability of both imaging modalities to specifically image the tumors and demonstrated the efficacy of the theranostic agent in cancer treatment, largely outperforming the clinical anticancer drug paclitaxel. Consequently, these dendrimer nanosystems constitute promising 19F-MRI agents for effective cancer management. This study offers a broad avenue to the construction of 19F-MRI agents and theranostics, exploiting self-assembling supramolecular dendrimer chemistry.


Assuntos
Dendrímeros , Flúor , Nanomedicina Teranóstica , Dendrímeros/química , Animais , Nanomedicina Teranóstica/métodos , Humanos , Camundongos , Flúor/química , Paclitaxel/química , Paclitaxel/uso terapêutico , Imageamento por Ressonância Magnética/métodos , Linhagem Celular Tumoral , Neoplasias Pancreáticas/diagnóstico por imagem , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/terapia , Imagem por Ressonância Magnética de Flúor-19/métodos , Camundongos Nus , Meios de Contraste/química
2.
Proc Natl Acad Sci U S A ; 120(7): e2215308120, 2023 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-36745793

RESUMO

Drug delivery systems (DDSs) that can overcome tumor heterogeneity and achieve deep tumor penetration are challenging to develop yet in high demand for cancer treatment. We report here a DDS based on self-assembling dendrimer nanomicelles for effective and deep tumor penetration via in situ tumor-secreted extracellular vesicles (EVs), an endogenous transport system that evolves with tumor microenvironment. Upon arrival at a tumor, these dendrimer nanomicelles had their payload repackaged by the cells into EVs, which were further transported and internalized by other cells for delivery "in relay." Using pancreatic and colorectal cancer-derived 2D, 3D, and xenograft models, we demonstrated that the in situ-generated EVs mediated intercellular delivery, propagating cargo from cell to cell and deep within the tumor. Our study provides a new perspective on exploiting the intrinsic features of tumors alongside dendrimer supramolecular chemistry to develop smart and effective DDSs to overcome tumor heterogeneity and their evolutive nature thereby improving cancer therapy.


Assuntos
Dendrímeros , Vesículas Extracelulares , Neoplasias , Humanos , Preparações Farmacêuticas/análise , Dendrímeros/química , Sistemas de Liberação de Medicamentos , Neoplasias/tratamento farmacológico , Microambiente Tumoral
3.
Proc Natl Acad Sci U S A ; 120(33): e2303385120, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37549284

RESUMO

Excessive cell-free DNA (cfDNA) in the serum and synovium is considered a causative factor of rheumatoid arthritis (RA). Thus, cfDNA scavenging by using cationic polymers has been an effective therapeutic avenue, while these stratagems still suffer from systemic toxicity and unstable capture of cfDNA. Here, inspired by the biological charge-trapping effects and active degradation function of enzyme-containing organelles in vivo, we proposed a cationic peptide dendrimer nanogel with deoxyribonuclease I (DNase I) conjugation for the treatment of RA. Benefitting from their naturally derived peptide components, the resultant nanogels were highly biocompatible. More attractively, by tailoring them with a larger size and higher surface charge density, these cationic nanogels could achieve the fastest targeting capability, highest accumulation amounts, longer persistence time, and superior DNA scavenging capacity in inflamed joints. Based on these features, we have demonstrated that the organelle mimicking cationic nanogels could significantly down-regulate toll-like receptor (TLR)-9 signaling pathways and attenuate RA symptoms in collagen-induced arthritis mice. These results make the bioinspired DNase I conjugated cationic nanogels an ideal candidate for treating RA and other immune dysregulation diseases.


Assuntos
Artrite Reumatoide , Ácidos Nucleicos Livres , Camundongos , Animais , Nanogéis/uso terapêutico , Artrite Reumatoide/tratamento farmacológico , Peptídeos/uso terapêutico , Desoxirribonuclease I
4.
Proc Natl Acad Sci U S A ; 120(21): e2220787120, 2023 05 23.
Artigo em Inglês | MEDLINE | ID: mdl-37186846

RESUMO

Nucleic acid therapeutics are becoming an important drug modality, offering the unique opportunity to address "undruggable" targets, respond rapidly to evolving pathogens, and treat diseases at the gene level for precision medicine. However, nucleic acid therapeutics have poor bioavailability and are chemolabile and enzymolabile, imposing the need for delivery vectors. Dendrimers, by virtue of their well-defined structure and cooperative multivalence, represent precision delivery systems. We synthesized and studied bola-amphiphilic dendrimers for cargo-selective and on-demand delivery of DNA and small interfering RNA (siRNA), both important nucleic acid therapeutics. Remarkably, superior performances were achieved for siRNA delivery with the second-generation dendrimer, yet for DNA delivery with the third generation. We systematically studied these dendrimers with regard to cargo binding, cellular uptake, endosomal release, and in vivo delivery. Differences in size both of the dendrimers and their nucleic acid cargos impacted the cooperative multivalent interactions for cargo binding and release, leading to cargo-adaptive and selective delivery. Moreover, both dendrimers harnessed the advantages of lipid and polymer vectors, while offering nanotechnology-based tumor targeting and redox-responsive cargo release. Notably, they allowed tumor- and cancer cell-specific delivery of siRNA and DNA therapeutics for effective treatment in different cancer models, including aggressive and metastatic malignancies, outperforming the currently available vectors. This study provides avenues to engineer tailor-made vectors for nucleic acid delivery and precision medicine.


Assuntos
Dendrímeros , Neoplasias , Ácidos Nucleicos , Humanos , Dendrímeros/química , Ácidos Nucleicos/química , RNA Interferente Pequeno/metabolismo , DNA , RNA de Cadeia Dupla
5.
Nano Lett ; 24(28): 8650-8657, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38949785

RESUMO

The ion permeability and selectivity of membranes are crucial in nanofluidic behavior, impacting industries ranging from traditional to advanced manufacturing. Herein, we demonstrate the engineering of ion-conductive membranes featuring angstrom-scale ion-transport channels by introducing ionic polyamidoamine (PAMAM) dendrimers for ion separation. The exterior quaternary ammonium-rich structure contributes to significant electrostatic charge exclusion due to enhanced local charge density; the interior protoplasmic channels of PAMAM dendrimer are assembled to provide additional degrees of free volume. This facilitates the monovalent ion transfer while maintaining continuity and efficient ion screening. The dendrimer-assembled hybrid membrane achieves high monovalent ion permeance of 2.81 mol m-2 h-1 (K+), reaching excellent mono/multivalent selectivity up to 20.1 (K+/Mg2+) and surpassing the permselectivities of state-of-the-art membranes. Both experimental results and simulating calculations suggest that the impressive ion selectivity arises from the significant disparity in transport energy barrier between mono/multivalent ions, induced by the "exterior-interior" synergistic effects of bifunctional membrane channels.

6.
Biochem Biophys Res Commun ; 705: 149729, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38452515

RESUMO

Breast cancer resistance to chemotherapy necessitates novel combination therapeutic approaches. Linc-RoR is a long intergenic noncoding RNA that regulates stem cell differentiation and promotes metastasis and invasion in breast cancer. Herein, we report a dual delivery system employing polyamidoamine dendrimers to co-administer the natural compound curcumin and linc-RoR siRNA for breast cancer treatment. Polyamidoamine dendrimers efficiently encapsulated curcumin and formed complexes with linc-RoR siRNA at an optimal N/P ratio. In MCF-7 breast cancer cells, the dendriplexes were effectively internalized and the combination treatment synergistically enhanced cytotoxicity, arresting the cell cycle at the G1 phase and inducing apoptosis. Linc-RoR gene expression was also significantly downregulated. Individual treatments showed lower efficacy, indicating synergism between components. Mechanistic studies are warranted to define the molecular underpinnings of this synergistic interaction. Our findings suggest dual delivery of linc-RoR siRNA and curcumin via dendrimers merits further exploration as a personalized therapeutic approach for overcoming breast cancer resistance.


Assuntos
Neoplasias da Mama , Curcumina , Dendrímeros , Poliaminas , RNA Longo não Codificante , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , RNA Interferente Pequeno/genética , Curcumina/farmacologia , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Linhagem Celular Tumoral
7.
Small ; : e2402146, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38888130

RESUMO

Acute lung injury (ALI) is the pathophysiological precursor of acute respiratory distress syndrome. It is characterized by increased oxidative stress and exaggerated inflammatory response that disrupts redox reactions and immune homeostasis in the lungs, thereby posing significant clinical challenges. In this study, an internally functionalized thioether-enriched dendrimer Sr-G4-PEG is developed, to scavenge both proinflammatory cytokines and reactive oxygen species (ROS) and restore homeostasis during ALI treatment. The dendrimers are synthesized using an efficient and orthogonal thiol-ene "click" chemistry approach that involves incorporating thioether moieties within the dendritic architectures to neutralize the ROS. The ROS scavenging of Sr-G4-PEG manifests in its capacity to sequester proinflammatory cytokines. The synergistic effects of scavenging ROS and sequestering inflammatory cytokines by Sr-G4-PEG contribute to redox remodeling and immune homeostasis, along with the modulation of the NLRP3-pyroptosis pathway. Treatment with Sr-G4-PEG enhances the therapeutic efficacy of ALIs by alleviating alveolar bleeding, reducing inflammatory cell infiltration, and suppressing the release of inflammatory cytokines. These results suggest that Sr-G4-PEG is a potent nanotechnological candidate for remodeling redox and immune homeostasis in the treatment of ALIs, demonstrating the great potential of dendrimer-based nanomedicine for the treatment of respiratory pathologies.

8.
Chemistry ; 30(20): e202400060, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38263351

RESUMO

Superatoms are promising as new building block materials that can be designed by precise controlling of the constituent atoms. Stannaspherene (Sn12 2-) is a rigid cage-like cluster with icosahedral symmetry, for which one-atom encapsulation was theoretically expected and detected in the gas phase. Here, a single-atom introduction method into stannaspherene using a dendrimer template with polyvinylpyrrolidone (PVP) protection is demonstrated. This advanced solution-phase synthesis allows not only the selective doping of one atom into the cluster cage, but also enable further detail characterization of optical and magnetic properties that were not possible in the gas-phase synthesis. In other words, this liquid-phase synthesis method has enabled the adaptation of detailed analytical methods. In this study, FeSn12 was synthesized and characterized, revealing that a single Fe atom introduction in the Sn12 2- cage result in the appearance of near-infrared emission and enhancement in the magnetism.

9.
Pharm Res ; 41(8): 1725-1736, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39048881

RESUMO

OBJECTIVE: The development of an efficient, multifunctional drug delivery system overcoming different obstacles generally associated with drug formulations, including the poor accumulation of the active principle in the target site and its sustained release for prolonged time. METHODS: Our study proposes the development of a fluorinated poly(amidoamine) (PAMAM) carrier prodrug combining drug release boosted in alkaline environments with a possible implementation in 19F MRI applications. In particular, we functionalized the terminal primary amines of PAMAM G2 and G4 through an ad hoc designed fluorinated ibuprofen-arginine Michael acceptor to obtain multifunctional ibuprofen-PAMAM-Arg conjugates. RESULTS: These carriers demonstrated pH-dependent and sustained ibuprofen release for more than 5 days. This advantage was observed in both weak alkaline and physiological buffer solutions, allowing to overcome the limits associated to the burst release from similar fluorinated Arg-PAMAM dendrimers with ibuprofen physically encapsulated. CONCLUSION: These findings, coupled to the high biocompatibility of the system, suggest a potential synergistic biomedical application of our conjugates, serving as vehicles for drug delivery and as 19F magnetic resonance imaging contrast agents.


Assuntos
Arginina , Dendrímeros , Portadores de Fármacos , Liberação Controlada de Fármacos , Ibuprofeno , Pró-Fármacos , Ibuprofeno/administração & dosagem , Ibuprofeno/química , Dendrímeros/química , Concentração de Íons de Hidrogênio , Pró-Fármacos/química , Pró-Fármacos/administração & dosagem , Portadores de Fármacos/química , Arginina/química , Halogenação , Preparações de Ação Retardada/química , Sistemas de Liberação de Medicamentos/métodos , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/farmacocinética , Humanos , Imageamento por Ressonância Magnética/métodos
10.
Macromol Rapid Commun ; 45(15): e2400158, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38651593

RESUMO

Carbon-chain dendritic polymers hold unique properties and promising applications. However, synthesizing carbon-chain dendrimers, beyond conjugated ones, remains a challenge. Here, the use of the iterative single unit monomer insertion technique for synthesizing 2.5 generation partial-carbon-chain dendrimers (G2.5) is described, utilizing bismaleimide as the core, a maleimide-trithiocarbonate conjugate as the branching unit, and indene as the spacer unit, following a divergent growth strategy. The optimized conditions for synthesizing the maleimide-trithiocarbonate branching unit are a bismaleimide to trithiocarbonate ratio of 5:1 and a reaction time of 30 min. The structures are verified using 1H nuclear magnetic resonance, gel permeation chromatography, and matrix-assisted laser desorption/ionization-time of flight mass spectra. A four-arm star polymer is then synthesized using the G2.5 as the core. This synthesis of a partial-carbon-chain dendrimer establishes a foundational step toward creating all-carbon-chain ones and may open new application avenues in material science.


Assuntos
Carbono , Dendrímeros , Dendrímeros/química , Dendrímeros/síntese química , Carbono/química , Estrutura Molecular , Maleimidas/química , Maleimidas/síntese química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Polimerização , Polímeros/química , Polímeros/síntese química
11.
Drug Resist Updat ; 68: 100935, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36774747

RESUMO

To develop next-generation nanomedicine, theranostic nanotherapeutic strategies are increasingly being emphasized. In recent years, it is observed that the effective lifetime of anti-bacterial and anti-cancer agent is diminishing, which undermines the economic incentives necessary for clinical development and therapeutic applications. Thus, novel formulations ought to not only kill drug resistant strains and cancerous cells but also inhibit their formation. Recently, metallic nanoparticles [for example- silver (Ag) nanoparticles] have been widely investigated for their biomedical applications. The so-called applications necessitate the inclusion of these nanoparticles inside polymeric matrices (for example- dendrimer) leading to chemical functionalization of the metallic nanoparticles. Silver and silver nanoparticles' antibacterial activity has already been well established over years. Dendrimers due to their homogeneous highly branched structure and uniform composition are perfectly suitable for the inclusion of silver nanoparticles [Ag NPs]. Recently, the increasing trend in the development of Ag-dendrimer nanocomposites is attributed to the excellent antibacterial activity of Ag as well as dendrimer's unique properties like variable functional terminal ends and potential antibacterial effect necessarily. This review provides an informative overview regarding the numerous aspects of bactericidal and other biomedical applications of Ag-dendrimer nanocomposites, particularly emphasizing analysis of existing research and prospective worth to the pharmaceutical sector in future.


Assuntos
Dendrímeros , Nanopartículas Metálicas , Nanocompostos , Humanos , Nanopartículas Metálicas/química , Prata/farmacologia , Prata/química , Estudos Prospectivos , Nanocompostos/química , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bactérias
12.
Caries Res ; 58(4): 387-398, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38330923

RESUMO

INTRODUCTION: Titanium tetrafluoride (TiF4) is an anticariogenic agent with high remineralizing potential. However, the acidic pH of TiF4 solution can limit its clinical application. The present study aimed to prepare and characterize a new TiF4-dendrimer inclusion complex and evaluate its ability to inhibit enamel demineralization under pH cycling conditions. METHODS: PEG-citrate dendrimer and TiF4-dendrimer inclusion complex were synthesized and their molecular structures were evaluated using Fourier-transform Infrared Spectroscopy (FTIR), Hydrogen Nuclear Magnetic Resonance (HNMR), and Liquid Chromatography-Mass Spectrometry (LC-MS) tests. Forty-eight enamel samples were prepared and randomly divided into four groups: distilled water (negative control), TiF4 solution (T), dendrimer solution (D), and TiF4-dendrimer solution (TD). The microhardness of the samples was measured initially. Next, the samples underwent pH cycling, were exposed to the solutions, the microhardness was measured again, and microhardness loss was calculated. EDX analysis was performed on the surface and cross-sectional segments of the samples. RESULTS: The microhardness loss was significantly higher in control (-65.1 ± 6.0) compared to other groups. No significant difference was observed between T (-47.9 ± 5.6) and D (-41.7 ± 12.0) and also D and TD (-40.5 ± 9.4) in this regard. Microhardness loss was significantly higher in T compared to TD group. The TD samples showed similar fluoride and titanium content in both surface and subsurface regions, while the T group had higher concentrations in the surface region. Moreover, the TD solution had a higher pH of 3.4 compared to the T solution's pH of 1.1. CONCLUSION: No significant difference was observed between the efficacy of TiF4-dendrimer and TiF4 solution in inhibiting demineralization while TiF4-dendrimer solution had the added advantage of having a higher pH.


Assuntos
Esmalte Dentário , Fluoretos , Titânio , Desmineralização do Dente , Desmineralização do Dente/prevenção & controle , Titânio/química , Titânio/farmacologia , Fluoretos/farmacologia , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/química , Concentração de Íons de Hidrogênio , Espectroscopia de Infravermelho com Transformada de Fourier , Técnicas In Vitro , Dendrímeros/farmacologia , Dendrímeros/química , Cariostáticos/farmacologia , Cariostáticos/química , Dureza , Cromatografia Líquida , Animais , Espectrometria de Massas , Espectroscopia de Ressonância Magnética , Espectrometria por Raios X , Polietilenoglicóis/farmacologia , Polietilenoglicóis/química , Ácido Cítrico/farmacologia , Humanos
13.
Sensors (Basel) ; 24(2)2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38257672

RESUMO

The amplification of the surface plasmon resonance (SPR) sensitivity for the foot-and-mouth disease (FMD) detection was studied using Poly(amidoamine) (PAMAM) succinamic-acid dendrimers. The dendrimers were conjugated with the complementary annealed with the aptamers capable of binding specifically to FMD peptides. The tethered layer of the dendrimer-conjugated double-stranded(ds)-aptamers was formed on the SPR sensor Au surface via a thiol bond between the aptamers and Au. After the tethered layer was formed, the surface was taken out of the SPR equipment. Then, the ds-aptamers on the surface were denatured to collect the dendrimer-conjugated single-stranded(ss)-complementary. The surface with only the remaining ss-aptamers was transferred again to the equipment. Two types of the injections, the FMD peptide only and the dendrimer-conjugated ss-complementary followed by the FMD peptides, were performed on the surface. The sensitivity was increased 20 times with the conjugation of the dendrimers, but the binding rate of the peptides became more than two times slower.


Assuntos
Dendrímeros , Febre Aftosa , Animais , Ressonância de Plasmônio de Superfície , Oligonucleotídeos , Peptídeos
14.
Nano Lett ; 23(23): 11193-11202, 2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38039401

RESUMO

The topically administered glaucoma medications usually encounter serious precorneal drug loss and low corneal penetration, leading to a low bioavailability. In addition, due to the complexity of glaucoma etiology, a single medication is often insufficient. In this work, we report a novel dendritic oligoethylenimine decorated liposome for codelivery of two antiglaucoma drugs, latanoprost and timolol. The liposome showed a uniform nanoscopic particle size, positive surface charge, and excellent dual-drug loading capacity. A prolonged precorneal retention is observed by using this liposomal delivery system. This liposomal delivery system presents increased cellular uptake and tight junctions opening capacity, contributing respectively to the transcellular and paracellular permeation, thereby enhancing the trans-corneal transportation. Following topical administration of one eye drop in brown Norway rats, the dual-drug-loaded liposome formulation resulted in a sustained and effective intraocular pressure reduction as long as 5 days, without inducing ocular inflammation, discomfort, and tissue damage.


Assuntos
Glaucoma , Lipossomos , Ratos , Animais , Lipossomos/uso terapêutico , Agentes Antiglaucoma , Glaucoma/tratamento farmacológico , Timolol/farmacologia , Timolol/uso terapêutico , Administração Tópica , Sistemas de Liberação de Medicamentos
15.
Int J Mol Sci ; 25(13)2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-39000306

RESUMO

The unique structure of G4.0 PAMAM dendrimers allows a drug to be enclosed in internal spaces or immobilized on the surface. In the conducted research, the conditions for the formation of the active G4.0 PAMAM complex with doxorubicin hydrochloride (DOX) were optimized. The physicochemical properties of the system were monitored using dynamic light scattering (DLS), circular dichroism (CD), and fluorescence spectroscopy. The Quartz Crystal Microbalance with Dissipation Monitoring (QCM-D) method was chosen to determine the preferential conditions for the complex formation. The highest binding efficiency of the drug to the cationic dendrimer was observed under basic conditions when the DOX molecule was deprotonated. The decrease in the zeta potential of the complex confirms that DOX immobilizes through electrostatic interaction with the carrier's surface amine groups. The binding constants were determined from the fluorescence quenching of the DOX molecule in the presence of G4.0 PAMAM. The two-fold way of binding doxorubicin in the structure of dendrimers was visible in the Isothermal calorimetry (ITC) isotherm. Fluorescence spectra and release curves identified the reversible binding of DOX to the nanocarrier. Among the selected cancer cells, the most promising anticancer activity of the G4.0-DOX complex was observed in A375 malignant melanoma cells. Moreover, the preferred intracellular location of the complexes concerning the free drug was found, which is essential from a therapeutic point of view.


Assuntos
Dendrímeros , Doxorrubicina , Dendrímeros/química , Doxorrubicina/química , Doxorrubicina/farmacologia , Humanos , Linhagem Celular Tumoral , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos , Sobrevivência Celular/efeitos dos fármacos
16.
Int J Mol Sci ; 25(6)2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38542106

RESUMO

This review describes the two-photon absorption properties of dendrimers, which are arborescent three-dimensional macromolecules differing from polymers by their perfectly defined structure. The two-photon absorption process is a third order non-linear optical property that is attractive because it can be used in a wide range of applications. In this review, dendrimers that were studied for their two-photon absorption properties are first described. Then, the use of dendritic TPA chromophores for light harvesting, photopolymerization, optical power limitation, cell imaging, singlet oxygen generation, and photodynamic therapy is described. This review thus proposes an overview of the properties and possible applications of two-photon absorbing dendrimers.


Assuntos
Dendrímeros , Fotoquimioterapia , Dendrímeros/química , Fármacos Fotossensibilizantes/química , Fotoquimioterapia/métodos , Fótons , Polímeros/química
17.
Molecules ; 29(9)2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38731451

RESUMO

A novel second-generation blue fluorescent polyamidoamine dendrimer peripherally modified with sixteen 4-N,N-dimethylaninoethyloxy-1,8-naphthalimide units was synthesized. Its basic photophysical characteristics were investigated in organic solvents of different polarity. It was found that in these solvents, the dendrimer is colorless and emitted blue fluorescence with different intensities depending on their polarity. The effect of the pH of the medium on the fluorescence intensity was investigated and it was found that in the acidic medium, the fluorescence is intense and is quenched in the alkaline medium. The ability of the dendrimer to detect metal ions (Pb2+, Zn2+, Mg2+, Sn2+, Ba2+, Ni2+, Sn2+, Mn2+, Co2+, Fe3+, and Al3+) was also investigated, and it was found that in the presence of Fe3+, the fluorescent intensity was amplified more than 66 times. The antimicrobial activity of the new compound has been tested in vitro against Gram-positive B. cereus and Gram-negative P. aeruginosa. The tests were performed in the dark and after irradiation with visible light. The antimicrobial activity of the compound enhanced after light irradiation and B. cereus was found slightly more sensitive than P. aeruginosa. The increase in antimicrobial activity after light irradiation is due to the generation of singlet oxygen particles, which attack bacterial cell membranes.


Assuntos
Dendrímeros , Testes de Sensibilidade Microbiana , Naftalimidas , Poliaminas , Naftalimidas/química , Naftalimidas/farmacologia , Dendrímeros/química , Dendrímeros/farmacologia , Poliaminas/química , Poliaminas/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , Fluorescência , Pseudomonas aeruginosa/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Bacillus cereus/efeitos dos fármacos , Luz , Corantes Fluorescentes/química , Espectrometria de Fluorescência
18.
Molecules ; 29(8)2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38675623

RESUMO

Since the discovery of cisplatin in the 1960s, the search for metallo-drugs that are more efficient than platinum complexes with negligible side effects has attracted much interest. Among the other metals that have been examined for potential applications as anticancer agents is copper. The interest in copper was recently boosted by the discovery of cuproptosis, a recently evidenced form of cell death mediated by copper. However, copper is also known to induce the proliferation of cancer cells. In view of these contradictory results, there is a need to find the most suitable copper chelators, among which Schiff-based derivatives offer a wide range of possibilities. Gathering several metal complexes in a single, larger entity may provide enhanced properties. Among the nanometric objects suitable for such purpose are dendrimers, precisely engineered hyperbranched macromolecules, which are outstanding candidates for improving therapy and diagnosis. In this review article, we present an overview of the use of a particular Schiff base, namely pyridine-imine, linked to the surface of dendrimers, suitable for complexing copper, and the use of such dendrimer complexes in biology, in particular against cancers.


Assuntos
Cobre , Iminas , Piridinas , Animais , Humanos , Antineoplásicos/química , Antineoplásicos/farmacologia , Quelantes/química , Quelantes/farmacologia , Complexos de Coordenação/química , Complexos de Coordenação/farmacologia , Cobre/química , Dendrímeros/química , Iminas/química , Neoplasias/tratamento farmacológico , Piridinas/química , Bases de Schiff/química
19.
AAPS PharmSciTech ; 25(3): 51, 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38424412

RESUMO

The term cosmetics refers to any substances or products intended for external application on the skin with the aim of protection and better appearance of the skin surface. The skin delivery system promotes the controlled and targeted delivery of active ingredients. The development of this system has been driven by challenges encountered with conventional cosmeceuticals, including low skin retention of active components, limited percutaneous penetration, poor water dispersion of insoluble active ingredients, and instability of effective components. The aim is to create cosmeceuticals that can effectively overcome these issues. This review focuses on various nanocarriers used in cosmeceuticals currently and their applications in skin care, hair care, oral care, and more. The importance of nanotechnology in the sphere of research and development is growing. It provides solutions to various problems faced by conventional technologies, methods, and product formulations thus taking hold of the cosmetic industry as well. Nowadays, consumers are investing in cosmetics only for better appearance thus problems like wrinkles, ageing, hair loss, and dandruff requires to be answered proficiently. Nanocarriers not only enhance the efficacy of cosmeceutical products, providing better and longer-lasting effects, but they also contribute to the improved aesthetic appearance of the products. This dual benefit not only enhances the final quality and efficacy of the product but also increases consumer satisfaction. Additionally, nanocarriers offer protection against UV rays, further adding to the overall benefits of the cosmeceutical product. Figure 1 represents various advantages of nanocarriers used in cosmeceuticals. Nanotechnology is also gaining importance due to their high penetration of actives in the deeper layers of skin. It can be said that nanotechnology is taking over all the drawbacks of the traditional products. Thus, nanocarriers discussed in this review are used in nanotechnology to deliver the active ingredient of the cosmeceutical product to the desired site.


Assuntos
Cosmecêuticos , Cosméticos , Humanos , Autocuidado , Pele , Absorção Cutânea
20.
Angew Chem Int Ed Engl ; 63(20): e202319849, 2024 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-38439625

RESUMO

Glycans on tumor cell surface have significant impacts in the immune-killing process. Here an ultra-galactocation to sialic acid (Sia) strategy is designed to hugely introduce galactose (Gal) to Sia and on tumor cells in vivo by using a penta-functional dendritic probe (Den@5F), which efficiently enhances the immune-killing of tumor cells. The Den@5F contains five different kinds of functional groups, including Gal, Cy5, amino, phenylboronic acid (PBA) and 4-(4-(hydroxymethyl)-2-methoxy-5-nitrophenoxy) butanoate (mNB), which can be conveniently prepared through a two-step reaction. After injecting into the tumor-bearing mouse, Den@5F can efficiently block Sia through the specific recognition between PBA and Sia on tumor cells and hugely introduce Gal through the subsequent photo-crosslinking between mNB and amino groups to multiply conjugate excessive Den@5Fs. The comprehensively blocked Sia can prevent the immune escape, and the hugely introduced Gal can promote the immune stimulation of the immune cells, which lead to an efficient enhancement of the immune-killing. The proposed strategy provides a significant and promising tool to promote the clinical immunotherapy of tumor.


Assuntos
Galactose , Ácido N-Acetilneuramínico , Ácido N-Acetilneuramínico/química , Humanos , Animais , Camundongos , Galactose/química , Linhagem Celular Tumoral , Dendrímeros/química , Dendrímeros/farmacologia , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Neoplasias/patologia
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