Entrapment of Peptidoglycans and Adamantyltripeptides into Liposomes: An HPLC Assay for Determination of Encapsulation Efficiency

Frkanec, Ruža; Travaš, Dijana; Krstanović, Marina; Halassy, Beata; Ljevaković, Đurđica; Vranešić, Branka; Frkanec, Leo; Tomašić, Jelka

doi:10.1081/lpr-120026452

Cited by 21 publications

(19 citation statements)

References 48 publications

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“…It is non-toxic and non-pyrogenic and thus suitable for potential use with human and veterinary vaccines. In our previous studies adjuvant activity of PGM in different experimental models has been demonstrated (Tomašic et al, 2000;Halassy Špoljar et al, 2002, Halassy et al, 2003Ljevakovic et al, 2003) and its encapsulation into negatively charged, multilamellar liposomes studied (Tomašic et al, 1982;Frkanec, Noething-Laslo et al, 2003;Frkanec, Travaš et al, 2003).…”

Section: Introductionmentioning

confidence: 93%

Effect of Liposomal Formulations and Immunostimulating Peptidoglycan Monomer (PGM) on the Immune Reaction to Ovalbumin in Mice

Habjanec

Frkanec

Halassy

et al. 2006

Journal of Liposome Research

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The adjuvant activity of liposomes and immunostimulating peptidoglycan monomer (PGM) in different formulations has been studied in mice model using ovalbumin (OVA) as an antigen. PGM is a natural compound of bacterial origin with well-defined chemical structure: GlcNAc-MurNAc-L-Ala-D-isoGln-mesoDpm(epsilonNH2)-D-Ala-D-Ala. It is a non-toxic, non-pyrogenic, and water-soluble immunostimulator. The aim of this study was to investigate the influence of different liposomal formulations of OVA, with or without PGM, on the production of total IgG, as well as of IgG1 and IgG2a subclasses of OVA-specific antibodies (as indicators of Th2 and Th1 type of immune response, respectively). CBA mice were immunized s.c. with OVA mixed with liposomes, OVA with PGM mixed with liposomes, OVA encapsulated into liposomes and OVA with PGM encapsulated into liposomes. Control groups were OVA in saline, OVA with PGM in saline, and OVA in CFA/IFA adjuvant formulation. The entrapment efficacy of OVA was monitored by HPLC method. The adjuvant activity of the mixture of OVA and empty liposomes, the mixture of OVA, PGM, and liposomes and PGM encapsulated with OVA into liposomes on production of total anti-OVA IgG was demonstrated. The mixture of PGM and liposomes exhibited additive immunostimulating effect on the production of antigen-specific IgGs. The analysis of IgG subclasses revealed that encapsulation of OVA into liposomes favors the stimulation of IgG2a antibodies, indicating the switch toward the Th1 type of immune response. When encapsulated into liposomes or mixed with liposomes, PGM induced a switch from Th1 to Th2 type of immune response. It could be concluded that appropriate formulations of antigen, PGM, and liposomes differently affect the humoral immune response and direct the switch in the type of immune response (Th1/Th2).

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Section: Introductionmentioning

confidence: 93%

Effect of Liposomal Formulations and Immunostimulating Peptidoglycan Monomer (PGM) on the Immune Reaction to Ovalbumin in Mice

Habjanec

Frkanec

Halassy

et al. 2006

Journal of Liposome Research

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“…The entrapment efficiency of OVA, PGM and Ad2TP2 in mannosylated liposomes was determined in accordance with previously developed methods. [34,36] The results of entrapment efficiency of OVA, PGM and Ad2TP2 into mannosylated liposomes are presented in Table 2.…”

Section: Determination Of the Entrapment Efficiency Of Ova And Immunomentioning

confidence: 99%

“…[31,34] Briefly, eggphosphatidylcholine, cholesterol and mannosyl-lypoconjugates (1, 2 or 3) in a molar ratio of 7 : 5 : 0,5 were dissolved in chloroform : methanol (2 : 1). The chloroform and methanol were evaporated to dryness under vacuum on a rotary evaporator, and then lipid film was hydrated with OVA in saline, concentration 1 mg/mL by gentle hand shaking.…”

Section: Preparation Of Mannosylated Liposomes Formulationsmentioning

confidence: 99%

Mannosylated Liposomes with Built-in Peptidoglycan Based Immunomodulators for Subunit Vaccine Formulations

Štimac¹,

Bendelja²,

Sikirić³

et al. 2017

Croat. Chem. Acta

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The aim of the present study is preparation of mannosylated liposomes with built-in small molecule immunopotentiators for targeted, receptors mediated, delivery of antigens. The liposomes were mannosylated in two ways, by covalent attachment of p-aminophenyl-α-Dmannopyranoside to the preformed liposomes and by incorporation of synthetic mono-, di-and tetramannosyl-lipoconjugates into the lipid bilayer of liposomes. Four different mannosylated liposome formulations with incorporated model antigen, ovalbumin (OVA), and immunomodulators, PGM and Ad2TP2, were prepared and characterized. The influence of mannosylated liposome formulations on the antigen-specific humoral immune response was investigated. It has been shown that mannosylated liposomal formulations did not enhance the humoral immune response and production of anti-OVA antibodies but they significantly affected the type of OVA specific immune reaction and directed it towards Th1 type.

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“…The coupling rate is an important index that reflects the quality of the immunoliposome. It is also influenced by many factors, including the coupling method, antibody type, and liposome quality [13]. The coupling rate of anti-VEGFR to the urea immunoliposome was 36.84%; it is expected that this can be further improved by optimizing the coupling conditions.…”

Section: Discussionmentioning

confidence: 99%

Urea immunoliposome inhibits human vascular endothelial cell proliferation for hemangioma treatment

Wang

et al. 2013

World J Surg Onc

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BackgroundUrea injection has been used in hemangioma treatment as sclerotherapy. It shrinks vascular endothelial cells and induces degeneration, necrosis, and fibrosis. However, this treatment still has disadvantages, such as lacking targeting and difficulty in controlling the urea dosage. Thus, we designed a urea immunoliposome to improve the efficiency of treatment.MethodsThe urea liposome was prepared by reverse phase evaporation. Furthermore, the urea immunoliposome was generated by coupling the urea liposome with a vascular endothelial growth factor receptor (VEGFR) monoclonal antibody using the glutaraldehyde cross-linking method. The influence of the urea immunoliposome on cultured human hemangioma vascular endothelial cells was observed preliminarily.ResultsUrea immunoliposomes showed typical liposome morphology under a transmission electron microscope, with an encapsulation percentage of 54.4% and a coupling rate of 36.84% for anti-VEGFR. Treatment with the urea immunoliposome significantly inhibited the proliferation of hemangioma vascular endothelial cells (HVECs) in a time- and dose-dependent manner.ConclusionsThe urea immunoliposome that we developed distinctly and persistently inhibited the proliferation of HVECs and is expected to be used in clinical hemangioma treatment.

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Entrapment of Peptidoglycans and Adamantyltripeptides into Liposomes: An HPLC Assay for Determination of Encapsulation Efficiency

Cited by 21 publications

References 48 publications

Effect of Liposomal Formulations and Immunostimulating Peptidoglycan Monomer (PGM) on the Immune Reaction to Ovalbumin in Mice

Effect of Liposomal Formulations and Immunostimulating Peptidoglycan Monomer (PGM) on the Immune Reaction to Ovalbumin in Mice

Mannosylated Liposomes with Built-in Peptidoglycan Based Immunomodulators for Subunit Vaccine Formulations

Urea immunoliposome inhibits human vascular endothelial cell proliferation for hemangioma treatment

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