Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 2 de 2
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Int J Pharm ; 661: 124465, 2024 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-39004290

RESUMO

Liposomes are one of the most important drug delivery vectors, nowadays used in clinics. In general, polyethylene glycol (PEG) is used to ensure the stealth properties of the liposomes. Here, we have employed hydrophilic, biocompatible and highly non-fouling N-(2-hydroxypropyl) methacrylamide (HPMA)-based copolymers containing hydrophobic cholesterol anchors for the surface modification of liposomes, which were prepared by the method of lipid film hydration and extrusion through 100 nm polycarbonate filters. Efficient surface modification of liposomes was confirmed by transmission electron microscopy, atomic force microscopy, and gradient ultracentrifugation. The ability of long-term circulation in the vascular bed was demonstrated in rabbits after i.v. application of fluorescently labelled liposomes. Compared to PEGylated liposomes, HPMA-based copolymer-modified liposomes did not induce specific antibody formation and did not activate murine and human complement. Compared with PEGylated liposomes, HPMA-based copolymer-modified liposomes showed a better long-circulating effect after repeated administration. HPMA-based copolymer-modified liposomes thus represent suitable new candidates for a generation of safer and improved liposomal drug delivery platforms.

2.
Ticks Tick Borne Dis ; 12(1): 101559, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33137638

RESUMO

Micro-computed tomography (micro-CT) is an exceptional imaging modality which is limited in visualizing soft biological tissues that need pre-examination contrasting steps, which can cause serious deformation to sizeable specimens like engorged ticks. The aim of this study was to develop a new technique to bypass these limitations and allow the imaging of fed ticks in their natural state. To accomplish this, adult Ixodes ricinus females were allowed to engorge in vitro on blood supplemented with PEGylated gold nanoparticles (PEG-AuNPs). In total, 73/120 females divided into 6 groups engorged on blood enriched with 0.07-2.16 mg PEG-AuNPs per ml of blood. No toxic effect was observed for any of the tested groups compared to the control group, in which 12/20 females engorged on clear blood. The ticks were scanned on a Bruker micro-CT SkyScan 1276. The mean radiodensity of the examined ticks exceeded 0 Hounsfield Units only in the case of the two groups with the highest concentration. The best contrast was observed in ticks engorged on blood with the highest tested concentration of 2.16 mg/mL PEG-AuNPs. In these ticks, the midgut and rectal sac were clearly visible. Also, the midgut lumen volume was computed from segmented image data. The reduction in midgut volume was documented during the egg development process. According to this pilot study, micro-CT of ticks engorged on blood supplemented with contrasting agents in vitro may reveal additional information regarding the engorged ticks' anatomy.


Assuntos
Ouro , Ixodes , Nanopartículas Metálicas , Microtomografia por Raio-X/métodos , Animais , Sangue , Comportamento Alimentar , Feminino
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA