Qualitative Histologic Assessment vs. Geomorphometric Analysis of Nerve Fiber Shape after the Intraneural Application of Liposomal Bupivacaine / Evaluación Histológica Cualitativa Versus Análisis Geomorfométrico de la Forma de la Fibra Nerviosa Después de la Aplicación Intraneural de Bupivacaína Liposomal

SUMMARY: The preserved form of all components of the nerve fiber is a prerequisite for the proper conduction of the nerve impulse. various factors can change the shape of nerve fibers. In everyday practice, qualitative histological analysis is the gold standard for detecting changes in shape. Geometric morphometry is an innovative method that objectively enables the assessment of changes in nerve fibers' shape after local anesthetics action. A total of sixty sciatic nerves were used as material, which was intraneural injected with saline solution in the control group (n=30), and a solution of 1.33 % liposomal bupivacaine (n=30) in the test group. After the animals were sacrificed, nerve samples were taken and histological preparations were made. The preparations were first described and examined using a qualitative histological method, after which digital images were made. The images were entered into the MorphoJ program and processed using the method of geometric morphometry. Qualitative histological examination revealed no differences in nerve fibers after intraneurally applied physiological solution and liposomal bupivacaine. Using the method of geometric morphometry, a statistically significant change in the shape of axons was found after intraneurally applied saline solution and liposomal bupivacaine (p=0.0059). No significant differences in histological changes were found after the qualitative histological analysis of nerve fiber cross-section preparations. A statistically significant change in the shape of nerve fiber axons was observed after geometric morphometric analysis of digital images after intraneural application of saline and liposomal bupivacaine.

La forma conservada de todos los componentes de la fibra nerviosa es un requisito previo para la conducción correcta del impulso nervioso. Varios factores pueden cambiar la forma de las fibras nerviosas. En la práctica diaria, el análisis histológico cualitativo es el estándar de oro para detectar cambios de forma. La morfometría geométrica es un método innovador que permite evaluar objetivamente los cambios en la forma de las fibras nerviosas después de la acción de los anestésicos locales. Se utilizó como material un total de sesenta nervios ciáticos, que se inyectaron intraneuralmente con solución salina en el grupo control (n=30), y una solución de bupivacaína liposomal al 1,33 % (n=30) en el grupo de prueba. Después de sacrificados los animales, se tomaron muestras de nervios y se realizaron preparaciones histológicas. Primero se describieron y examinaron las preparaciones utilizando un método histológico cualitativo, después de lo cual se tomaron imágenes digitales. Las imágenes fueron ingresadas al programa MorphoJ y procesadas mediante el método de morfometría geométrica. El examen histológico cualitativo no reveló diferencias en las fibras nerviosas después de la aplicación intraneural de solución fisiológica y bupivacaína liposomal. Usando el método de morfometría geométrica, se encontró un cambio estadísticamente significativo en la forma de los axones después de la aplicación intraneural de solución salina y bupivacaína liposomal (p = 0,0059). No se encontraron diferencias significativas en los cambios histológicos después del análisis histológico cualitativo de las preparaciones de secciones transversales de fibras nerviosas. Se observó un cambio estadísticamente significativo en la forma de los axones de las fibras nerviosas después del análisis de morfometría geométrica de imágenes digitales después de la aplicación intraneural de solución salina y bupivacaína liposomal.

Eugenol and its liposome-based nano carrier reduce anxiety by inhibiting glyoxylase-1 expression in mice / Eugenol e seu nanocarreador à base de lipossoma reduzem a ansiedade ao inibir a expressão de glioxalase 1 em camundongos

Abstract The most common form of psycho-social dysfunction is anxiety with depression being related closely without any age bar. They are present with combined state of sadness, confusion, stress, fear etc. Glyoxalase system contains enzyme named glyoxalase 1 (GLO1).It is a metabolic pathway which detoxifies alpha-oxo-aldehydes, particularly methylglyoxal (MG). Methylglyoxal is mainly made by the breakdown of the glycolytic intermediates, glyceraldehyde-3-phosphates and dihydroxyacetone phosphate. Glyoxylase-1 expression is also related with anxiety behavior. A casual role or GLO-1 in anxiety behavior by using viral vectors for over expression in the anterior cingulate cortex was found and it was found that local GLO-1 over expression increased anxiety behavior. The present study deals with the molecular mechanism of protective activity of eugenol against anxiolytic disorder. A pre-clinical animal study was performed on 42 BALB/c mice. Animals were given stress through conventional restrain model. The mRNA expression of GLO-1 was analyzed by real time RT-PCR. Moreover, the GLO-1 protein expression was also examined by immunohistochemistry in whole brain and mean density was calculated. The mRNA and protein expressions were found to be increased in animals given anxiety as compared to the normal control. Whereas, the expressions were decreased in the animals treated with eugenol and its liposome-based nanocarriers in a dose dependent manner. However, the results were better in animals treated with nanocarriers as compared to the compound alone. It is concluded that the eugenol and its liposome-based nanocarriers exert anxiolytic activity by down-regulating GLO-1 protein expression in mice.

Resumo A forma mais comum de disfunção psicossocial é a ansiedade intimamente relacionada com a depressão, sem qualquer barreira de idade. Elas estão presentes em um estado combinado de tristeza, confusão, estresse, medo etc. O sistema de glioxalase contém uma enzima chamada glioxalase 1 (GLO1). É uma via metabólica que desintoxica alfa-oxo-aldeídos, particularmente metilglioxal (MG). O metilglioxal é produzido principalmente pela quebra dos intermediários glicolíticos, gliceraldeído-3-fosfatos e fosfato de diidroxiacetona. A expressão da glioxalase 1 também está relacionada ao comportamento de ansiedade. Um papel casual ou GLO1 no comportamento de ansiedade usando vetores virais para superexpressão no córtex cingulado anterior foi encontrado e descobriu-se que a superexpressão local de GLO1 aumentava o comportamento de ansiedade. O presente estudo trata do mecanismo molecular da atividade protetora do eugenol contra o transtorno ansiolítico. Um estudo pré-clínico em animais foi realizado em 42 camundongos BALB / c. Os animais foram submetidos ao estresse por meio do modelo de contenção convencional. A expressão de mRNA de GLO1 foi analisada por RT-PCR em tempo real. Além disso, a expressão da proteína GLO1 também foi examinada por imuno-histoquímica em todo o cérebro e a densidade média foi calculada. Verificou-se que as expressões de mRNA e proteínas estavam aumentadas em animais que receberam ansiedade em comparação com o controle normal. Considerando que as expressões foram diminuídas nos animais tratados com eugenol e seus nanocarreadores baseados em lipossomas de forma dependente da dose. No entanto, os resultados foram melhores em animais tratados com nanocarreadores em comparação com o composto sozinho. Conclui-se que o eugenol e seus nanocarreadores baseados em lipossomas exercem atividade ansiolítica por regulação negativa da expressão da proteína GLO1 em camundongos.

Preparation of an ophthalmic formulation of TPGS-modified insulin-loaded liposomes and its in vitro corneal permeation and pharmacokinetics in rabbit eyes / 南方医科大学学报

OBJECTIVE@#To prepare vitamin E polyethylene glycol 1000 succinate (TPGS)-modified insulin-loaded liposomes (T-LPs/INS) and evaluate its safety, corneal permeability, ocular surface retention and pharmacokinetics in rabbit eyes.@*METHODS@#The safety of the preparation was investigated in human corneal endothelial cells (HCECs) using CCK8 assay and live/dead cell staining. In the ocular surface retention study, 6 rabbits were randomized into 2 equal groups for application of fluorescein sodium dilution or T-LPs/INS labeled with fluorescein in both eyes, which were photographed under cobalt blue light at different time points. In the cornea penetration test, another 6 rabbits divided into 2 groups for application of Nile red diluent or T-LPs/INS labeled with Nile red in both eyes, after which the corneas were harvested for microscopic observation. In the pharmacokinetic study, 2 groups of rabbits (n=24) were treated with eye drops of T-LPs/INS or insulin, and the aqueous humor and cornea were collected at different time points for measurement of insulin concentrations using enzyme linked immunosorbent assay. DAS2 software was used to analyze the pharmacokinetic parameters.@*RESULTS@#The prepared T-LPs/INS showed good safety in cultured HCECs. Corneal permeability assay and fluorescence tracer ocular surface retention assay demonstrated a significantly higher corneal permeability of T-LPs/INS with a prolonged drug residence in the cornea. In the pharmacokinetic study, insulin concentrations in the cornea at 6, 15, 45, 60, and 120 min (P < 0.01) and in the aqueous humor at 15, 45, 60, and 120 min after dosing were significantly higher in T-LPs/INS group. The changes in insulin concentrations in the cornea and aqueous humor were consistent with a two-compartment model in T-LPs/INS group and with the one-compartment model in the insulin group.@*CONCLUSION@#The prepared T-LPs/INS shows an improved corneal permeability, ocular surface retention capacity and eye tissue concentration of insulin in rabbits.

Effects of intranasal administration of tripterygium glycoside-bearing liposomes on behavioral cognitive impairment of mice induced by central nervous system inflammation / 中国中药杂志

Tripterygium glycosides liposome(TPGL) were prepared by thin film-dispersion method, which were optimized accor-ding to their morphological structures, average particle size and encapsulation rate. The measured particle size was(137.39±2.28) nm, and the encapsulation rate was 88.33%±1.82%. The mouse model of central nervous system inflammation was established by stereotaxic injection of lipopolysaccharide(LPS). TPGL and tripterygium glycosides(TPG) were administered intranasally for 21 days. The effects of intranasal administration of TPG and TPGL on behavioral cognitive impairment of mice due to LPS-induced central ner-vous system inflammation were estimated by animal behavioral tests, hematoxylin-eosin(HE) staining of hippocampus, real-time quantitative polymerase chain reaction(RT-qPCR) and immunofluorescence. Compared with TPG, TPGL caused less damage to the nasal mucosa, olfactory bulb, liver and kidney of mice administered intranasally. The behavioral performance of treated mice was significantly improved in water maze, Y maze and nesting experiment. Neuronal cell damage was reduced, and the expression levels of inflammation and apoptosis related genes [tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), BCL2-associated X(Bax), etc.] and glial activation markers [ionized calcium binding adaptor molecule 1(IBA1) and glial fibrillary acidic protein(GFAP)] were decreased. These results indicated that liposome technique combined with nasal delivery alleviated the toxic side effects of TPG, and also significantly ameliorated the cognitive impairment of mice induced by central nervous system inflammation.

Advances in anti-invasive fungal drug delivery systems / 浙江大学学报·医学版

Currently, the first-line drugs for invasive fungal infections (IFI), such as amphotericin B, fluconazole and itraconazole, have drawbacks including poor water solubility, low bioavailability, and severe side effects. Using drug delivery systems is a promising strategy to improve the efficacy and safety of traditional antifungal therapy. Synthetic and biomimetic carriers have greatly facilitated the development of targeted delivery systems for antifungal drugs. Synthetic carrier drug delivery systems, such as liposomes, nanoparticles, polymer micelles, and microspheres, can improve the physicochemical properties of antifungal drugs, prolong their circulation time, enhance targeting capabilities, and reduce toxic side effects. Cell membrane biomimetic drug delivery systems, such as macrophage or red blood cell membrane-coated drug delivery systems, retain the membrane structure of somatic cells and confer various biological functions and specific targeting abilities to the loaded antifungal drugs, exhibiting better biocompatibility and lower toxicity. This article reviews the development of antifungal drug delivery systems and their application in the treatment of IFI, and also discusses the prospects of novel biomimetic carriers in antifungal drug delivery.

Ginsenoside Rg_3 based liposomes target delivery of dihydroartemisinin and paclitaxel for treatment of triple-negative breast cancer / 中国中药杂志

Ginsenoside Rg_3, an active component of traditional Chinese medicine(TCM), was used as the substitute for cholesterol as the membrane material to prepare the ginsenoside Rg_3-based liposomes loaded with dihydroartemisinin and paclitaxel. The effect of the prepared drug-loading liposomes on triple-negative breast cancer in vitro was evaluated. Liposomes were prepared with the thin film hydration method, and the preparation process was optimized by single factor experiments. The physicochemical properties(e.g., particle size, Zeta potential, and stability) of the liposomes were characterized. The release behaviors of drugs in different media(pH 5.0 and pH 7.4) were evaluated. The antitumor activities of the liposomes were determined by CCK-8 on MDA-MB-231 and 4T1 cells. The cell scratch test was carried out to evaluate the effect of the liposomes on the migration of MDA-MB-231 and 4T1 cells. Further, the targeting ability of liposomes and the mechanism of lysosome escape were investigated. Finally, H9c2 cells were used to evaluate the potential cardiotoxicity of the preparation. The liposomes prepared were spheroid, with uniform particle size distribution, the ave-rage particle size of(107.81±0.01) nm, and the Zeta potential of(2.78±0.66) mV. The encapsulation efficiency of dihydroartemisinin and paclitaxel was 57.76%±1.38% and 99.66%±0.07%, respectively, and the total drug loading was 4.46%±0.71%. The accumulated release of dihydroartemisinin and paclitaxel from the liposomes at pH 5.0 was better than that at pH 7.4, and the liposomes could be stored at low temperature for seven days with good stability. Twenty-four hours after administration, the inhibition rates of the ginsenoside Rg_3-based liposomes loaded with dihydroartemisinin(70 μmol·L~(-1)) and paclitaxel on MDA-MB-231 and 4T1 cells were higher than those of the positive control(adriamycin) and free drugs(P<0.01). Compared with free drugs, liposomes inhibited the migration of MDA-MB-231 and 4T1 cells(P<0.05). Liposomes demonstrated active targeting and lysosome escape. In particular, liposomes showed lower toxicity to H9c2 cells than free drugs(P<0.05), which indicated that the preparation had the potential to reduce cardiotoxicity. The findings prove that ginsenoside Rg_3 characterized by the combination of drug and excipient is an ideal substitute for lipids in liposomes and promoted the development of innovative TCM drugs for treating cancer.

A real-world study on the efficacy and safety analysis of paclitaxel liposome in advanced breast cancer / 中华肿瘤杂志

Objective: To explore the application and efficacy of paclitaxel liposome in the treatment of advanced breast cancer among Chinese population in the real world. Methods: The clinical characteristics of patients with advanced breast cancer who received paclitaxel liposome as salvage treatment from January 1, 2016 to August 31, 2019 in 11 hospitals were collected and retrospectively analyzed. The primary outcome was progression free survival (PFS), and the secondary outcome included objective response rate (ORR) and safety. The survival curve was drawn by Kaplan-Meier analysis and the Cox regression model were used for the multivariate analysis. Results: Among 647 patients with advanced breast cancer who received paclitaxel liposome, the first-line treatment accounted for 43.3% (280/647), the second-line treatment accounted for 27.7% (179/647), and the third-line and above treatment accounted for 29.1% (188/647). The median dose of first-line and second-line treatment was 260 mg per cycle, and 240 mg in third line and above treatment. The median period of paclitaxel liposome alone and combined chemotherapy or targeted therapy is 4 cycles and 6 cycles, respectively. In the whole group, 167 patients (25.8%) were treated with paclitaxel liposome combined with capecitabine±trastuzumab (TX±H), 123 patients (19.0%) were treated with paclitaxel liposome alone (T), and 119 patients (18.4%) were treated with paclitaxel liposome combined with platinum ± trastuzumab (TP±H), 108 patients (16.7%) were treated with paclitaxel liposome combined with trastuzumab ± pertuzumab (TH±P). The median PFS of first-line and second-line patients (5.5 and 5.5 months, respectively) were longer than that of patients treated with third line and above (4.9 months, P<0.05); The ORR of the first line, second line, third line and above patients were 46.7%, 36.8% and 28.2%, respectively. Multivariate analysis showed that event-free survival (EFS) and the number of treatment lines were independent prognostic factors for PFS. The common adverse events were myelosuppression, gastrointestinal reactions, hand foot syndrome and abnormal liver function. Conclusion: Paclitaxel liposomes is widely used and has promising efficacy in multi-subtype advanced breast cancer.

Praziquantel-encapsulated niosomes against Schistosoma mansoni with reduced sensitivity to praziquantel / Niosomas encapsulados en prazicuantel contra Schistosoma mansoni con sensibilidad reducida al prazicuantel

Introduction: Praziquantel (PZQ) is the only commercially available drug for schistosomiasis. The current shortage of alternative effective drugs and the lack of successful preventive measures enhance its value. The increase in the prevalence of PZQ resistance under sustained drug pressure is, therefore, an upcoming issue. Objective: To overcome the tolerance to PZQ using nanotechnology after laboratory induction of a Schistosoma mansoni isolate with reduced sensitivity to the drug during the intramolluscan phase. Materials and methods: Shedding snails were treated with PZQ doses of 200 mg/kg twice/ week followed by an interval of one week and then repeated twice in the same manner. The success of inducing reduced sensitivity was confirmed in vitro via the reduction of cercarial response to PZQ regarding their swimming activity and death percentage at different examination times. Results: Oral treatment with a single PZQ dose of 500 mg/kg in mice infected with cercariae with reduced sensitivity to PZQ revealed a non-significant reduction (35.1%) of total worm burden compared to non-treated control mice. Orally inoculated PZQ- encapsulated niosomes against S. mansoni with reduced sensitivity to PZQ successfully regained the pathogen's sensitivity to PZQ as evidenced by measuring different parameters in comparison to the non-treated infected animals with parasites with reduced sensitivity to PZQ. The mean total worm load was 1.33 ± 0.52 with a statistically significant reduction of 94.09% and complete eradication of male worms. We obtained a remarkable increase in the percentage reduction of tissue egg counts in the liver and intestine (97.68% and 98.56%, respectively) associated with a massive increase in dead eggs and the complete absence of immature stages. Conclusion: PZQ-encapsulated niosomes restored the drug sensitivity against laboratory- induced S. mansoni adult worms with reduced sensitivity to PZQ.

Introducción. El prazicuantel es el único fármaco disponible comercialmente para la esquistosomiasis. La escasez actual de medicamentos alternativos y la falta de medidas preventivas eficaces aumentan su valor. La creciente prevalencia de la resistencia al prazicuantel bajo una presión prolongada del fármaco es, por tanto, un tema emergente. Objetivos. Superar la tolerancia al prazicuantel mediante nanotecnología después de la inducción en laboratorio de un aislamiento de Schistosoma mansoni con sensibilidad reducida al fármaco durante la fase intramolusco. Materiales y métodos. Los caracoles que liberaban cercarias se trataron con prazicuantel en dosis de 200 mg/kg dos veces por semana, seguidas de un intervalo de una semana, y luego se repitieron dos veces de la misma manera. La inducción exitosa de la sensibilidad reducida se confirmó in vitro mediante la reducción de la reacción de las cercarias al prazicuantel con respecto a su actividad de natación y el porcentaje de muerte en diferentes momentos de examen. El éxito en inducir una menor sensibilidad se confirmó in vitro mediante la reducción de la reacción de las cercarias al prazicuantel. Resultados. El tratamiento oral con una dosis única de prazicuantel de 500 mg/kg en ratones infectados con cercarias con sensibilidad reducida al prazicuantel, reveló una reducción no significativa (35,1 %) de la carga total de gusanos en comparación con los ratones de control no tratados. Los niosomas encapsulados en prazicuantel inoculados por vía oral contra S. mansoni con sensibilidad reducida al prazicuantel, permitieron reestablecer con éxito la sensibilidad del patógeno al medicamento, como lo demostró la medición de diferentes parámetros en comparación con los animales infectados no tratados con parásitos con sensibilidad reducida a prazicuantel. La carga media total de gusanos fue de 1,33 ± 0,52, con una reducción estadísticamente significativa del 94,09 %, y la erradicación completa de los gusanos machos adultos. Se obtuvo un aumento notable en el porcentaje de reducción del recuento de huevos en el tejido del hígado y el intestino (97,68 % y 98,56 %, respectivamente), asociado con un aumento masivo de huevos muertos y ausencia total de estadios inmaduros. Conclusión. Los niosomas encapsulados en prazicuantel restauraron la sensibilidad al fármaco contra gusanos adultos de S. mansoni con sensibilidad reducida al prazicuantel inducida en el laboratorio.

Desenvolvimento e caracterização de lipossomas peguilados para veiculação de L-asparaginase / Development and characterization of peg-grafted liposomes for lasparaginase encapsulation

A Leucemia Linfoide Aguda (LLA) é um câncer de maior incidência em crianças, e tem a Lasparaginase (ASNase) como fármaco amplamente utilizado no tratamento dos afetados. A ASNase catalisa a hidrólise do aminoácido L-asparagina (Asn), presente na corrente sanguínea, a ausência do aminoácido no meio extracelular leva à morte células leucêmicas, que necessitam deste aminoácido para as funções celulares. Fatores envolvendo a eficiência do tratamento com ASNase como reações adversas e curta meia-vida, principalmente devido ao reconhecimento pelo sistema imune e degradação por proteases, limitam a sua eficácia. A encapsulação da enzima em lipossomas pode conferir proteção à degradação, melhorar seu perfil farmacocinético e diminuir os efeitos adversos, de forma a melhorar o tratamento da LLA sendo este o objetivo desse trabalho. Lipossomas de DOPC (1,2-dioleoil-sn-glicero-3-fosfocolina) e DMPC (1,2-dimiristoil-snglicero-3-fosfocolina) foram desenvolvidos empregando-se o método de hidratação do filme lipídico e diferentes protocolos de preparo contendo ou não diferentes concentrações de 18:0 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polietilenogicol)-2000] (DSPE-PEG). Os lipossomas produzidos foram utilizados para encapsular a ASNase e os sistemas contendo ou não ASNase encapsulada foram caracterizados por espalhamento de luz dinâmico (DLS), potencial zeta, microscopia eletrônica de transmissão (MET) e criomicroscopia de transmissão. Adicionalmente, foram avaliados a taxa de encapsulação e o perfil de permeabilidade das vesículas à L-asparagina. As análises de DLS mostraram que as nanoestruturas formadas empregando-se agitação magnética a partir de sistemas contendo 10% e 20% de DSPE-PEG possuem diâmetro hidrodinâmico menor (~ 25 nm a 60 nm) que os mesmos sistemas sem o fosfolipídio peguilado (~190 nm a 222 nm), demonstrando a relação entre a diminuição do tamanho e o aumento da quantidade de fosfolipídio peguilado e possível formação de estruturas micelares ou bicelares. O emprego de agitação em vórtex para hidratação do filme lipídico, adição do antioxidante -tocoferol e redução da concentração de DSPE-PEG (5% e 10%) levou à formação de sistemas com diâmetro hidrodinâmico maior, sendo esse protocolo e concentrações de PEG definidos como padrão. As análises de MET comprovaram a formação de lipossomas com diâmetro hidrodinâmico semelhante ao observado por DLS; com a utilização da criomicroscopia foi possível observar os lipossomas sem deformações. Os lipossomas de DMPC/DSPE-PEG 10% apresentaram maior permeabilidade à L-asparagina ao longo do tempo e, portanto, poderiam funcionar como nanoreatores, depletando o aminoácido da circulação. Estudos in vitro com células tumorais devem ser realizados e em seguida estudos in vivo, para confirmar este potencial

L-asparaginase (ASNase) is a first-choice drug, combined with other drugs, in therapeutic schemes to treat Acute Lymphoblastic Leukemia (ALL) in children and adolescents. ASNase catalyzes the hydrolysis of L-asparagine (Asn) in the bloodstream; since ALL cells cannot synthesize this amino acid, protein synthesis is impaired leading to leukemic cells death by apoptosis. In spite of its therapeutic importance, treatment with ASNase is associated to side effects, mainly hypersensitivity and immunogenicity. Another drawback refers to degradation by plasma proteases that altogether with immunogenicity shortens the enzyme half-life. Encapsulation of ASNase in liposomes, vesicular nanostructures formed by the self-aggregation of phospholipids, is an attractive alternative that possibly will protect the enzyme from plasma proteases, resulting on better pharmacokinetics profile. In this work, we prepared by thin film hydration liposomal formulations of the phospholipid 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) or 1,2-dimyristoyl-sn-glycero-3- phosphocholine (DMPC) containing or not different concentrations of 18:0 1,2-distearoyl-snglycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG), and encapsulated ASNase by electroporation. The systems containing or not ASNase were analyzed by Dynamic Light Scattering, zeta potential and Electron Microscopy. The encapsulation efficiency and vesicles permeability were also evaluated. According to the DLS analysis, the nanostructures formed by film hydration under magnetic stirring employing 10% or 20% DSPE-PEG presented smaller hydrodynamic diameter (~ 25 nm to 60 nm) than the same systems without the pegylated phospholipid (~ 190 nm to 222 nm), demonstrating the relation between size and the amount of pegylated phospholipid that results in formation of micellar or bicellar structures. The protocol was stabilize by hydration of the lipid film under vortex agitation, addition of the antioxidant - tocopherol and reduction of the concentration of DSPE-PEG (5% and 10%), what altogether led to the formation of nanostructures of higher hydrodynamic diameter and monodisperse systems. TEM analyzes confirmed the formation of liposomes with hydrodynamic diameter similar to that observed by DLS; with the use of cryomicroscopy it was possible to observe the liposomes without deformations. Liposomes of DMPC/DSPE-PEG 10% showed permeability to L-asparagine over time and, therefore, could function as nanoreactors, depleting the circulating amino acid

Progresses on active targeting liposome drug delivery systems for tumor therapy / 生物医学工程学杂志

Liposome is an ideal drug carrier with many advantages such as excellent biocompatibility, non-immunogenicity, and easy functionalization, and has been used for the clinical treatment of many diseases including tumors. For the treatment of tumors, liposome has some passive targeting capability, but the passive targeting effect alone is very limited in improving the drug enrichment in tumor tissues, and active targeting is an effective strategy to improve the drug enrichment. Therefore, active targeting liposome drug-carriers have been extensively studied for decades. In this paper, we review the research progresses on active targeting liposome drug-carriers based on the specific binding of the carriers to the surface of tumor cells, and summarize the opportunities, challenges and future prospects in this field.

Study on the effect of small alcohol on lipid hydration and liposome formation / 生物医学工程学杂志

Liposomes with precisely controlled composition are usually used as membrane model systems to investigate the fundamental interactions of membrane components under well-defined conditions. Hydration method is the most common method for liposome formation which is found to be influenced by composition of the medium. In this paper, the effects of small alcohol (ethanol) on the hydration of lipid molecules and the formation of liposomes were investigated, as well as its coexistence with sodium chloride. It was found that ethanol showed the opposite effect to that of sodium chloride on the hydration of lipid molecules and the formation of liposomes. The presence of ethanol promoted the formation of liposomes within a certain range of ethanol content, but that of sodium chloride suppressed the liposome formation. By investigating the fluorescence intensity and continuity of the swelled membranes as a function of contents of ethanol and sodium chloride, it was found that sodium chloride and ethanol showed the additive effect on the hydration of lipid molecules when they coexisted in the medium. The results may provide some reference for the efficient preparation of liposomes.

Preparation of tanshinone Ⅱ_A-glycyrrhetinic acid solid lipid nanoparticles and its inhibitory effect on acne / 中国中药杂志

The optimal prescription of tanshinone Ⅱ_A(TSN)-glycyrrhetinic acid(GA) solid lipid nanoparticles(GT-SLNs) was explored and evaluated in vivo and in vitro, and its effect on acne after oral administration was investigated. The preparation processing and prescription were optimized and verified by single factor and response surface methodology. The in vitro release of GA and TSN in GT-SLNs was determined by ultra-performance liquid chromatography(UPLC). The effect of GT-SLNs on acne was investigated by the levels of sex hormones in mice, ear swelling model, and tissue changes in sebaceous glands, and the pharmacokinetics was evaluated. The 24-hour cumulative release rates of GA and TSN in SLNs were 65.87%±5.63% and 36.13%±2.31% respectively. After oral administration of GT-SLNs and the mixture of GA and TSN(GT-Mix), the AUC_(0-t) and AUC_(0-∞) of TSN in GT-SLNs were 1.98 times and 4.77 times those in the GT-Mix group, respectively, and the peak concentration of TSN in the GT-SLNs group was 17.2 times that in the GT-Mix group. After intragastric administration of GT-SLNs, the serum levels of testosterone(T) and the ratio of testosterone to estradiol(T/E2) in the GT-SLNs group significantly declined, and the sebaceous glands of mice were atrophied to a certain extent. The results demonstrated that obtained GT-SLNs with good encapsulation efficiency and uniform particle size could promote the release of GA and TSN. GT-SLNs displayed therapeutic efficacy on acne manifested by androgen increase, abnormal sebaceous gland secretion, and inflammatory damage.

Amplification of urea detection based on pH-sensitive liposomes

BACKGROUND: This study aimed to develop an amplification method of urea detection based on pHsensitive liposomes. RESULTS: The urease covalently immobilized on the magnetic particles and the pH-sensitive liposomes encapsulating ferricyanide were added to the cyclic-voltammeter cell solution where urea was distributed. The conversion of urea into carbonic acid seemed to induce a pH decrease that caused a reduction in the electrostatic repulsion between the headgroups of weakly acidic 1,2-dipalmitoyl-sn-glycero3-succinate. The reduction induced the liposomes to release potassium ferricyanide that was encapsulated inside. The effects of urea concentration and pH value were investigated. A specific concentration (0.5 mg/mL) of the urea solution was set to observe the response. The activity of urease was reversible with respect to the pH change between 7 and 5. The sensitivity of this detection was almost identical to the comparable techniques such as an enzyme-linked immunosorbent assay and a field-effect transistor. CONCLUSIONS: In summary, the methodology developed in this study was feasible as a portable, rapid, and sensitive method.

In vivo study of liposome-modified polyetheretherketone implant on bacteriostasis and osseointegration / 北京大学学报(医学版)

OBJECTIVE@#To develop dexamethasone plus minocycline-loaded liposomes (Dex/Mino liposomes) and apply them to improve bioinert polyetheretherketone (PEEK) surface, which could prevent post-operative bacterial contamination, enhance ossification for physiologic osseointegration, and finally reduce implant failure rates.@*METHODS@#Dex/Mino liposomes were covalently grafted onto the PEEK surface using polydopamine (pDA) coating as a medium. Confocal laser scanning microscopy was used to confirm the binding of fluorescently labeled liposomes onto the PEEK substrate, and a microplate reader was used to semiquantitatively measure the average fluorescence intensity of fluorescently labeled liposome-decorated PEEK surfaces. Moreover, the mouse subcutaneous infection model and the beagle femur implantation model were respectively conducted to verify the bioactivity of Dex/Mino liposome-modified PEEK in vivo, by means of micro computed tomography (micro-CT) and hematoxylin and eosin (HE) staining analysis.@*RESULTS@#The qualitative and quantitative results of fluorescently labeled liposomes showed that, the red fluorescence intensity of the PEEK-pDA-lipo group was stronger than that of the PEEK-NF-lipo group (P < 0.05); the liposomes were successfully and uniformly decorated on the PEEK surfaces due to the pDA coating. After mouse subcutaneous implantation of PEEKs for 24 hours, HE staining results showed that the number of inflammatory cells in the PEEK-Dex/Mino lipo group were lower than that in the inert PEEK group (P < 0.05), indicating a lower degree of infection in the test group. These results suggested that the Mino released from the liposome-functionalized surface provided an effective bacteriostasis in vivo. After beagle femoral implantation of PEEK for 8 weeks, micro-CT results showed that the PEEK-Dex/Mino lipo group newly formed more continuous bone when compared with the inert PEEK group; HE staining results showed that more new bones were formed in the PEEK-Dex/Mino lipo group than in the inert PEEK group, which were firmly bonded to the functionalized PEEK surface and extended along the PEEK interface. These results suggested that the Dex released from the liposome-functionalized surface induced effective bone regeneration in vivo.@*CONCLUSION@#Dex/Mino liposome modification enhanced the bioactivity of inert PEEK, the functionalized PEEK with enhanced antibacterial and osseointegrative capacity has great potential as an orthopedic/dental implant material for clinical application.

Characterization of purified coconut oil bodies as an encapsulating agent for Doxorubicin and Paclitaxel

Introduction@#Doxorubicin (DOX) and paclitaxel (PTX) are both widely used anticancer drugs with a broad spectrum of antitumor activity, commonly against breast, ovarian, and lung cancers. Currently, these drugs are commercially available in liposomal formulations for their use in chemotherapy. This study generally proposed coconut oil bodies (COB) obtained from Cocos nucifera L. as an alternative carrier for DOX and PTX rather than the currently used liposome. @*Objectives@#This study aimed to compare standard liposome and coconut oil bodies as drug carriers in terms of their microencapsulation efficiencies, lipid profiles, in vitro drug release and stability, as well as their cholesterol levels.@*Methods@#Coconut oil bodies (COB) were isolated and purified from Cocos nucifera L. by modified sucrose gradient method followed by microencapsulation of standard drugs (doxorubicin and paclitaxel) through selfassembly and freeze-thaw method. The two standard drugs were encapsulated using COB and standard liposome. Encapsulation efficiency of both materials were determined. Lipid profiles of both encapsulating materials were analyzed by Fourier-transform infrared spectroscopy, gas chromatography-flame ionization detector, and cholesterol level determination. In vitro drug release and pH stability of both encapsulated drugs were analyzed. @*Results@#Doxorubicin (DOX) and paclitaxel (PTX) were successfully incorporated in COB. Lauric acid was mainly abundant in COB and was able to lower cholesterol levels (5 mg/dL). COB incorporated with DOX and PTX showed stability at acidic and neutral pH. Drug release profile showed a rapid outburst within 3 hours compared to liposome encapsulated DOX and PTX. @*Conclusion@#Our study showed the encouraging potentials of using COB as wall materials that will make them attractive candidates for the formulation of pharmaceuticals for optimized drug delivery of cancer chemotherapeutics DOX and PTX

Doxorubicin Hydrochloride Liposome-Based CHOP Regimen in the Initial Treatment of Elderly Patients with Diffuse Large B-Cell Lymphoma: A Retrospective Study / 中国实验血液学杂志

OBJECTIVE@#To evaluate the efficacy and safety of CHOP regimen based on doxorubicin hydrochloride liposome in the initial treatment of elderly patients with diffuse large B-cell lymphoma (DLBCL).@*METHODS@#Thirty-one patients with DLBCL treated from January 1, 2012 to December 31, 2019 were analyzed retrospectively, their median age was 83 (71-95) years old, and all of them were in Ⅲ-Ⅳ stage, including 17 cases who had international prognostic index (IPI) ≥ 3. The patients were treated with R-CHOP and CHOP regimens based on doxorubicin hydrochloride liposome. The efficacy and safety were evaluated during and after treatment.@*RESULTS@#A total of 219 chemotherapy cycles and 7 median cycles were performed in 31 patients. The overall response (OR) rate and complete remission (CR) rate was 80.7% (25/31) and 61.3% (19/31), respectively, as well as 2 cases (6.5%) stable, 4 cases (12.9%) progressive. The main toxicities were as follows: the incidence of grade Ⅲ -Ⅳ neutropenia was 29% (9/31); two patients (6.5%) developed degree Ⅰ-Ⅱ cardiac events, which were characterized by new degree Ⅰ atrioventricular block; there were no cardiac events requiring emergency treatment and discontinuation of chemotherapy. The 1-year, 2-year and 3-year overall survival rate was 83.9%, 77.4% and 61.3%, respectively. The 1-year, 2-year and 3-year progression-free survival rate was 77.4%, 64.5% and 61.3%, respectively.@*CONCLUSION@#The chemotherapy regimen based on doxorubicin hydrochloride liposome has better efficacy and higher cardiac safety for elderly patients with DLBCL.

Production of glycosylphosphatidylinositol-anchored proteins for vaccines and directed binding of immunoliposomes to specific cell types

Liposomes are highly useful carriers for delivering drugs or antigens. The association of glycosylphosphatidylinositol (GPI)-anchored proteins to liposomes potentially enhances the immunogenic effect of vaccine antigens by increasing their surface concentration. Furthermore, the introduction of a universal immunoglobulin-binding domain can make liposomes targetable to virtually any desired receptor for which antibodies exist. Methods: We developed a system for the production of recombinant proteins with GPI anchors and histidine tags and Strep-tags for simplified purification from cells. This system was applied to i) the green fluorescent protein (GFP) as a reporter, ii) the promising Plasmodium falciparum vaccine antigen PfRH5 and iii) a doubled immunoglobulin Fc-binding domain termed ZZ from protein A of Staphylococcus aureus. As the GPI-attachment domain, the C-terminus of murine CD14 was used. After the recovery of these three recombinant proteins from Chinese hamster ovary (CHO) cells and association with liposomes, their vaccine potential and ability to target the CD4 receptor on lymphocytes in ex vivo conditions were tested. Results: Upon immunization in mice, the PfRH5-GPI-loaded liposomes generated antibody titers of 103 to 104, and showed a 45% inhibitory effect on in vitro growth at an IgG concentration of 600 µg/mL in P. falciparum cultures. Using GPI-anchored ZZ to couple anti-CD4 antibodies to liposomes, we created immunoliposomes with a binding efficiency of 75% to CD4+ cells in splenocytes and minimal off-target binding. Conclusions: Proteins are very effectively associated with liposomes via a GPI-anchor to form proteoliposome particles and these are useful for a variety of applications including vaccines and antibody-mediated targeting of liposomes. Importantly, the CHO-cell and GPI-tagged produced PfRH5 elicited invasion-blocking antibodies qualitatively comparable to other approaches.(AU)

Preparation and characterization of liposomes loaded with silver nanoparticles obtained by green synthesis

The objective of this work was to develop and characterize liposomes loaded with silver nanoparticles (LAgNPs) to show improvement in stability characteristics. AgNPs were prepared by the green synthesis method with Aloe vera gel extract and exposure to sunlight. Liposomes were prepared by the modified reverse phase method. Particle size, polydispersity index, zeta potential, as well as the scanning electron microscopy (SEM) morphological aspects of AgNPs and LAgNPs were evaluated. In addition, was used flame atomic absorption spectroscopy to determine the amount of AgNP that was encapsulated in liposomes. The AgNPs presented as amorphous and polydisperse structures, with a mean diameter of 278.46 nm and zeta potential of -18.3 mV. LAgNPs had a mean diameter between 321 and 373 nm, the polydispersity index close to 0.2 and a zeta potential around -40 mV, which indicates greater stability to the AgNPs. The images obtained by SEM show semicircular structures for AgNPs and well-defined spherical shape for LAgNPs. The percentage of encapsulation was between 51.81 to 58.83%. These results showed that LAgNPs were obtained with adequate physicochemical characteristics as a release system.

Comparative analyses of response surface methodology and artificial neural networks on incorporating tetracaine into liposomes

This study evaluated the incorporation of tetracaine into liposomes by RSM (Response Surface Methodology) and ANN (Artificial Neural Networks) based models. RCCD (rotational central composite design) and ANN were performed to optimize the sonication conditions of particles containing 100 % lipid. Laser light scattering was used to perform measure hydrodynamic radius and size distribution of vesicles. The liposomal formulations were analyzed by incorporating the drug into the hydrophilic phase or the lipophilic phase. RCCD and ANN were conducted, having the lipid/cholesterol ratio and concentration of tetracaine as variables investigated and, the encapsulation efficiency and mean diameter of the vesicles as response variables. The optimum sonication condition set at a power of 16 kHz and 3 minutes, resulting in sizes smaller than 800 nm. Maximum encapsulation efficiency (39.7 %) was obtained in the hydrophilic phase to a tetracaine concentration of 8.37 mg/mL and 79.5:20.5% lipid/cholesterol ratio. Liposomes were stable for about 30 days (at 4 ºC), and the drug encapsulation efficiency was higher in the hydrophilic phase. The experimental results of RCCD-RSM and ANN techniques show ANN obtained more refined prediction errors that RCCD-RSM technique, therefore, ANN can be considered as an efficient mathematical method to characterize the incorporation of tetracaine into liposomes.

Preparation of warangalone-loaded liposomes and its inhibitory effect on breast cancer cells / 南方医科大学学报

OBJECTIVE@#To prepare warangalone-loaded thermosensitive liposomes (WLTSL) and evaluate its inhibitory effect on breast cancer cells .@*METHODS@#MTT assay was used to assess the changes in proliferation of 3 breast cancer cell lines (MDA-MB-231, MCF7, and SKBR3) following treatment with warangalone, soy isoflavone and genistein. Colony-forming assay and wound healing assay was used to assess colony forming activity and migration of MDA-MB-231 cells treated with warangalone. The effect of warangalone on the expression of MMP2 and MMP9 in MDA-MB-231 cells was examined with Western blotting. The thermosensitive liposomes (TSL) and WLTSL were prepared using a thin film hydration method, and the morphology, size, encapsulation efficiency and stability of the prepared liposomes were characterized using transmission electron microscopy, dynamic light scattering scanning and UV spectrophotometry. MTT assay was used to examine the inhibitory effect of WLTSL on mouse breast cancer cells (4T1) .@*RESULTS@#Warangalone showed stronger anti-proliferation effects than soy isoflavones and genistein in the 3 human breast cancer cell lines and significantly inhibited colony formation by MDA-MB-231 cells. Treatment with warangalone significantly inhibited migration of the breast cancer cells and down-regulated the cellular expressions of MMP2 and MMP9. The prepared TSL and WLTSL presented with a homogeneous, irregular spherical morphology, with a mean particle size of 56.23±0.61 nm, a polymer dispersity index of 0.241±0.014, a Zeta potential of -40.40±0.46 mV, and an encapsulation efficiency was 87.68±2.41%. WLTSL showed a good stability at 4 ℃ and 37 ℃ and a stronger inhibitory effect than warangalone in 4T1 cells.@*CONCLUSIONS@#Warangalone inhibits the proliferation, migration and invasion of breast cancer cells, and the prepared WLTSL possesses good physical properties and strong anti-breast cancer activity.