Liposome Suspensions Research Articles

Liposomal Bupivacaine Decreases Pain Scores and Narcotic Use After Cesarean Delivery [19E

INTRODUCTION: Liposomal bupivacaine (LB; Exparel 1.3%) is an extended-release, local anesthetic administered perioperatively for management of postoperative (PO) pain. When used as a liposomal suspension, bupivacaine has a fast onset of action with a duration up to 72 hours. This study examines patient reported pain scores (PRPain) and total morphine equivalents (ME) in patients receiving LB administration via transversus abdominis plane block (LB-TAP) or incisional infiltration (LB-II). METHODS: Women receiving LB-TAP (n=107) or LB-II (n=185) after cesarean delivery between January 2018 and January 2019 were included in the study. LB-TAP under ultrasound guidance and LB-II were performed by obstetrician-gynecologists. The infusion solution (80 mL, consisted of 20 ml 1.3% liposomal bupivacaine, 30 ml 1/2% bupivacaine and 30 ml injectable saline) was compounded by the pharmacy and sent to the operating room for injection. Primary endpoints are PRPain scores (10-point visual analog scale) and total PO ME used. RESULTS: Women receiving LB-TAP (5.5±1.6) reported higher PRPain than women receiving LB-II (4.6±1.7) on PO day 0 (P<.001). However, groups did not differ on PRPain on PO day 1 or PO day 2. Groups were similar for total ME (LB-TAP=25.18 mg ±42.2 vs LB-II=24.92 mg ±51.3; P<.97). CONCLUSION: Our results show that initial differences in PRPain scores on PO day 0 for women receiving LB-TAP versus LB-II were not evident on PO day 1 or PO day 2. LB-TAP and LB-II resulted in similar ME, which was noted to be much lower than a recently published narcotics reducing protocol.

The effect of vehicle on skin absorption of Mg2+ and Ca2+ from thermal spring water.

Thermal spring waters (TSW) are commonly used as active ingredients in cosmetics. Their biological activities directly depend on the ionic composition of the spring. However, in order to exhibit beneficial properties, the minerals need to reach viable skin layers. The present study addresses the incorporation of marketed TSW in model cosmetic formulations and the impact of the formulation on skin absorption of magnesium and calcium ions that are known to improve skin barrier function. Marketed TSW was introduced into five formulations. Liposomes were prepared using saturated or unsaturated phospholipids mixed with cholesterol by the thin layer evaporation technique. Emulsions water-in-oil (W/O), oil-in-water (O/W) or double: water-in-oil-in-water (W/O/W) were prepared by high-shear mixing. Skin absorption of Mg2+ and Ca2+ from those formulations was studied invitro using static Franz diffusion cells under infinite dose condition and under occlusion of the apparatus. Mg2+ and Ca2+ penetrate skin samples from TSW. Encapsulating TSW into double emulsion (TSW/O/W) increased skin absorption of both cations of interest and kept the Ca2+ /Mg2+ ratio equal to that of TSW in each skin layer. The dermal absorption of Mg2+ from the double emulsion departs from both single emulsions. Application of liposome suspension improved the skin absorption of Ca2+ while keeping constant that of Mg2+ , leading to unbalanced Ca2+ /Mg2+ ratio inside skin. The beneficial effects of TSW are not only due to their action on the skin surface. Their active components, especially Ca2+ and Mg2+ cations, reach viable skin layers in a formulation-dependent manner. The distribution of ions inside skin depends on the type of formulation.

Randomized trial of bupivacaine with epinephrine versus bupivacaine liposome suspension in patients undergoing minimally invasive lung resection

ObjectivesThoracic surgery can cause significant pain, and multiple strategies have been developed to control pain after surgery. We compared 2 bupivacaine formulations given intraoperatively: bupivacaine with epinephrine (1,200,000) or liposomal bupivacaine. MethodsThis was a randomized, open-label study (NCT03560362). Eligible patients were adults scheduled for a minimally invasive lung procedure. Incision sites were injected with bupivacaine with epinephrine or liposomal bupivacaine before incision, and each intercostal space was injected with 1 mL of bupivacaine with epinephrine or liposomal bupivacaine entering the thoracic cavity. Patient-controlled analgesia was initiated in the recovery room. Pain was recorded using a visual analog scale. The primary outcome was the amount of narcotics taken during the postoperative hospital stay. ResultsWe recruited 50 patients; 25 received bupivacaine with epinephrine, and 25 received liposomal bupivacaine. The treatment groups were similar in age, histology, and procedure performed. There were no statistical differences between the treatment groups in the amount of narcotics required during the hospital stay (36.3 mg for bupivacaine and 38 mg for liposomal bupivacaine) or in pain assessed the day of surgery (5 and 5), the first day (3.5 and 2.3), second day (3 and 2.6), 2 weeks (0 and 1), or 3 months (0 and 0) postoperatively. Hospital length of stay and complications were also similar. ConclusionsIn a small, randomized study, we did not find significant differences between bupivacaine with epinephrine or liposomal bupivacaine in mitigating pain after minimally invasive lung resection. We currently favor using the less expensive nonliposomal bupivacaine preparations until additional data are available.

Retention of Eucalyptol, a Natural Volatile Insecticide, in Delivery Systems Based on Hydroxypropyl‐β‐Cyclodextrin and Liposomes

AbstractEucalyptol (Euc) is a natural monoterpene with insecticide effects. Being highly volatile and sensitive to ambient conditions, its encapsulation would enlarge its application. Euc‐loaded conventional liposomes (CL), cyclodextrin/drug inclusion complex, and drug‐in‐cyclodextrin‐in‐liposomes (DCL) are prepared to protect Euc from degradation, reduce its evaporation, and provide its controlled release. The liposomal suspension is freeze‐dried using hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) as cryoprotectant. The liposomes are characterized before and after freeze‐drying. The effect of Euc on the fluidity of liposomal membrane is also examined. A release study of Euc from delivery systems, in powder and reconstituted forms, is performed by multiple head extraction at 60 °C after 6 months of storage at 4 °C. CL and DCL suspensions are homogeneous, show nanometric vesicles size, spherical shape, and negative surface charge before and after freeze‐drying. Moreover, HP‐β‐CD does not affect the fluidity of liposomes. CL formulations present a weak encapsulation for Euc. The loading capacity of eucalyptol in DCL is 38 times higher than that in CL formulation. In addition, freeze‐dried DCL and HP‐β‐CD/Euc inclusion complex show a higher retention of eucalyptol than CL delivery system. Both carrier systems HP‐β‐CD/Euc and Euc‐loaded DCL decrease Euc evaporation and improve its retention.Practical Applications: Eucalyptol is a natural insecticide. It is highly volatile and poorly soluble in water. To enlarge its application, its encapsulation in three delivery systems (conventional liposomes, cyclodextrin/drug inclusion complex, combined system composed of cyclodextrin inclusion complex and liposome) is studied. In this paper it is proved that cyclodextrin/eucalyptol inclusion complex and eucalyptol‐in‐cyclodextrin‐in‐liposome are effective delivery systems for encalyptol encapsulation, retention, and release.

Amikacin Liposome Inhalation Suspension for Mycobacterium avium Complex Lung Disease

OBJECTIVE: To review the pharmacology, pharmacokinetics, pharmacodynamics, clinical efficacy, safety, administration, and role of amikacin liposome inhalation suspension (ALIS) in treatment of Mycobacterium avium complex (MAC) lung disease.<br/> DATA SOURCES: A PubMed search using the terms "amikacin inhaled," "nebulized," and "liposome suspension" was performed. Selected infectious diseaseconference posters were also examined for relevant information. In addition, pertinent guidelines were reviewed.<br/> STUDY SELECTION/DATA EXTRACTION: Guidelines for the management of nontuberculous mycobacterial infections from the American Thoracic Society/ Infectious Diseases Society of America and the British Thoracic Society were used to summarize guidelinebased therapy (GBT). A phase II and a phase III clinical trial were reviewed to evaluate the role of ALIS in the treatment of MAC lung disease.<br/> DATA SYNTHESIS: ALIS is a new formulation of inhaled amikacin (AMK) indicated for the treatment of MAC lung disease refractory to GBT in adults who are not candidates for intravenous AMK. An ongoing clinical trial has demonstrated that once-daily ALIS plus GBT results in higher rates of culture conversion compared with GBT alone by month 6 among patients with a mean age of 65 years. The most common adverse reactions associated with ALIS were dysphonia, cough, bronchospasm, hemoptysis, and ototoxicity. Nephrotoxicity was uncommon.<br/> CONCLUSION: ALIS has been shown to increase culture conversion rates when added to GBT in adults with difficult-to-treat MAC lung disease. ALIS is associated with high rates of pulmonary and auditory adverse reactions and a low risk of renal adverse reactions. ALIS may be an attractive treatment option for older adults who are at high risk for nephrotoxicity.

Amikacin Liposome Inhalation Suspension for Mycobacterium avium Complex Lung Disease.

OBJECTIVE: To review the pharmacology, pharmacokinetics, pharmacodynamics, clinical efficacy, safety, administration, and role of amikacin liposome inhalation suspension (ALIS) in treatment of Mycobacterium avium complex (MAC) lung disease.<br/> DATA SOURCES: A PubMed search using the terms "amikacin inhaled," "nebulized," and "liposome suspension" was performed. Selected infectious diseaseconference posters were also examined for relevant information. In addition, pertinent guidelines were reviewed.<br/> STUDY SELECTION/DATA EXTRACTION: Guidelines for the management of nontuberculous mycobacterial infections from the American Thoracic Society/ Infectious Diseases Society of America and the British Thoracic Society were used to summarize guidelinebased therapy (GBT). A phase II and a phase III clinical trial were reviewed to evaluate the role of ALIS in the treatment of MAC lung disease.<br/> DATA SYNTHESIS: ALIS is a new formulation of inhaled amikacin (AMK) indicated for the treatment of MAC lung disease refractory to GBT in adults who are not candidates for intravenous AMK. An ongoing clinical trial has demonstrated that once-daily ALIS plus GBT results in higher rates of culture conversion compared with GBT alone by month 6 among patients with a mean age of 65 years. The most common adverse reactions associated with ALIS were dysphonia, cough, bronchospasm, hemoptysis, and ototoxicity. Nephrotoxicity was uncommon.<br/> CONCLUSION: ALIS has been shown to increase culture conversion rates when added to GBT in adults with difficult-to-treat MAC lung disease. ALIS is associated with high rates of pulmonary and auditory adverse reactions and a low risk of renal adverse reactions. ALIS may be an attractive treatment option for older adults who are at high risk for nephrotoxicity.

Thermosensitive in situ liposomal gels loaded with antimicrobial agent for oral care in critically ill patients.

Aim: A novel thermosensitive in situ gel loaded with meropenem (MP) liposomes was designed to improve retention in the oral cavity as a prophylactic measure to prevent ventilator-acquired pneumonia in critically ill patients. Methodology &results: Meropenem liposomes were incorporated into poloxamer 407 gels and gamma irradiated. Mean size of liposome was 247nm, polydispersity index < 0.3 and zeta potential >-25mV; properties remained unaltered even post sterilization. Permeation study revealed that 75.26% and 34% of MPs were released from MP in situ gel and MP in situ liposomal gel, respectively. The relation between viscosity (cp) and shear rate (1/s) indicate that in situ gels exhibited non-Newtonian behavior at 37°C. The study using Pseudomonas aeruginosa confirmed the antimicrobial activity of meropenem. Conclusion: Prolonged in situ residence, because of rapid gelation process enables an easy administration of meropenem as liposomal suspension in critically ill patients.

Effects of Curcumin on Lipid Membranes: an EPR Spin-label Study

Curcumin is a yellow–orange dye widely used as a spice, food coloring and food preservative. It also exhibits a broad range of therapeutic effects against different disorders such as cancer, diabetes, or neurodegenerative diseases. As a compound insoluble in water curcumin accumulates in cell membranes and due to this location it may indirectly lead to the observed effects by structurally altering the membrane environment. To exert strong structural effects on membrane curcumin needs to adopt a transbilayer orientation. However, there is no agreement in literature as to curcumin’s orientation and its structural effects on membranes. Here, we investigated the effects of curcumin on lipid order, lipid phase transition, and local polarity in a model liposome membranes made of DMPC or DSPC using electron paramagnetic resonance (EPR) spin labeling technique. Curcumin affected lipid order at different depths within the membrane: it slightly increased the phospholipid polar headgroup mobility as monitored by spectral parameters of T-PC, while along the acyl chain the ordering effect was observed in terms of order parameter S. Also, rotational correlation times τ2B and τ2C of 16-PC in the membrane center were increased by curcumin. Polarity measurements performed in frozen suspensions of liposomes revealed enhancement of water penetration by curcumin in the membrane center (16-PC) and in the polar headgroup region (T-PC) while the intermediate positions along the acyl chain (5-PC and 10-PC) were not significantly affected. Curcumin at a lower concentration (5 mol%) shifted the temperature of the DMPC main phase transition to lower values and increased the transition width, and at a higher concentration (10 mol%) abolished the transition completely. The observed effects suggest that curcumin adopts a transbilayer orientation within the membrane and most probably form oligomers of two molecules, each of them spanning the opposite bilayer leaflets. The effects are also discussed in terms of curcumin’s protective activity and compared with those imposed on membranes by other natural dyes known for their protective role, namely polar carotenoids, lutein and zeaxanthin.

Preparation and Rheological Properties of Cross-linked Liposomes Using Hydroxypropylmethylcellulose Bearing a Hydrophobic Anchor

Hydrophobically-modified hydroxypropylmethylcellulose (HM-HPMC) is a thickener with a long hydrophobic alkyl side chain. In this study, we investigated the gelation ability and rheological properties of a liposome/HM-HPMC mixed solution. The liposome suspension and the HM-HPMC aqueous solution each had low viscosities, but the viscosity increased rapidly when they were mixed. This is thought to be due to the formation of a 3D network structure caused by the hydrophobic group of HM-HPMC penetrating into the liposomal bilayer membrane, crosslinking the liposomes together. This hypothesis was supported by the fact that gelation did not occur when hydroxypropylmethylcellulose without a hydrophobic group was used. The viscosity of the liposome/HM-HPMC mixed solution decreased rapidly when a shear was applied, but immediately returned to the original gel state when the shear was removed, indicating a reversible reaction. When a strong shear is applied, the hydrophobic group of HM-HPMC detaches from the liposome. When the shear is removed, the liposome is again cross-linked by HM-HPMC. From these results, it was revealed that liposome cross-linked gels can be prepared when HM-HPMC is used.

Structural Changes in the Lungs and Liver of Mice with Experimental Tuberculosis Treated with Liposome-Encapsulated Dextrazide.

Male BALB/с mice were intravenously infected with Mycobacterium tuberculosis H37Rv (0.5 ml of 2-week culture). One month later, treatment with liposome-encapsulated dextrazide (LEDZ, a conjugate of isonicotinic acid hydrazide (INH) and 40 kDa oxidized dextran encapsulated in phosphatidylcholine liposomes), INH, or a combination of LEDZ with INH was started. The doses of LEDZ (liposome suspension) and INH were 0.025 ml/10 g body weight and 5 mg/kg body weight, respectively. All the substances were administered 2 times a week via inhalation or intraperitoneally (a total of 40 doses). We studied the number and the size of tuberculous granulomas, the size of destruction foci and inflammatory infiltrates in the lungs and liver, the amount of fibrous connective tissue, and the dynamic of these parameters. LEDZ+INH inhalations were most effective by the therapeutic ratios in comparison with inhalation and intraperitoneal injections of INH.

Вивчення спорідненості до мембран допоміжних речовин й фармакологічно активних інгредієнтів методами флуоресцентних і спінових зондів

Мета дослідження – порівняльне вивчення спорідненості до ліпосом з фосфатидилхоліну низки гідрофільних неводних розчинників пропіленгліколю (ПГ), поліетиленгліколей (ПЕГ) з молекулярною масою 400 і 1500 (ПЕГ­400 і ПЕГ­1500), що успішно застосовуються за створення м’яких лікарських форм як допоміжні речовини. Проведено аналіз результатів, отриманих за допомогою методу флуоресцентних зондів, і розрахунок константи дисоціації (Кд) неводних розчинників ПГ, ПЕГ­400 і ПЕГ­1500 з мембранами ліпосом з фосфатидилхоліну графічним методом у зворотних координатах. Показано, що Кд = 2,5 моль/л для ПГ і Кд = 4 • 10 ­1 моль/л для ПЕГ­400. Аналіз спектрів електронно­парамагнітного резонансу (ЕПР) у зворотних координатах дозволив оцінити Кд для ПЕГ­1500, що дорівнює 10­1 моль/л. Досліджено вплив ПГ і ПЕГ­400 на мембрани ліпосом. ПГ і ПЕГ­400 ефективно зв’язуються з мембраною ліпосом, витісняючи флуоресцентний зонд з мембрани в воду. Це може бути одним із механізмів впливу ПГ і ПЕГ­400 на біодоступність, коли фармакологічно активні інгредієнти (ФАІ) можуть витиснятися в воду молекулами допоміжних речовин, сповільнюючи процес всмоктування ФАІ. Введення ПЕГ­400 у суспензію ліпосом призводить до розпушення мембран, тобто, до зменшення щільності упаковки фосфоліпідів у мембранах, що може призводити до зміни їхньої проникності та підвищенню біодоступності. Дія ПГ на мембрани є більш м’якою, ніж ПЕГ­400. Вочевидь у зоні всмоктування ФАІ на мембрані паралельно відбувається процес всмоктування низькомолекулярних допоміжних речовин, наприклад, неводних розчинників. Причому всмоктування ліпофільних ФАІ може відбуватися в оточенні розчинників (допоміжних речовин), що призводить до збільшення біодоступності ФАІ. У разі конкуренції за місця зв’язування на мембранах клітин біоповерхонь між ФАІ і неводними розчинниками більш низька (на кілька порядків) спорідненість розчинників до мембран компенсується значною кількістю розчинників у м’якій лікарській формі порівняно з ФАІ. Механізмом підвищення біосумісності за допомогою ПЕГ є здатність їхніх молекул за рахунок компактизації (спіралізації) або розпушення приймати оптимальну конформацію структури, надаючи свої гідрофобні або полярні групи для оптимального зв’язування з наночастинками, лікарськими речовинами та біооб’єктами.

Lipid bilayer hydrodynamic drag

The hydrodynamic drag at a lipid bilayer surface determines in part the flow properties of suspensions of cells and liposomes. Given the fluidity of lipid bilayers, it is not obvious a priori whether solid-like no-slip, liquid-like no-stress, or intermediate boundary conditions apply at the water-bilayer interface. Though no-slip conditions have been widely assumed for many decades, this fundamental aspect of membrane rheology has, to our knowledge, never been directly measured for free bilayers. We applied light sheet fluorescence microscopy to image freely diffusing phospholipid vesicles and determined the hydrodynamic drag coefficient $C \pi \eta R$, where $\eta$ is the external fluid viscosity, $R$ is the vesicle radius, and the dimensionless $C$ characterizes the flow boundary condition. We find that $C = 5.92 \pm 0.13$ (stat.) $\pm 0.16$ (syst.), matching the theoretical value of $C=6$ for a no-slip boundary and far from the $C=4$ value for a zero shear stress boundary

The Role of Exparel Plus Meloxicam for Postoperative Pain Management.

Acute postoperative pain reduction is a major target against the opioid crisis. While opioids have traditionally been the mainstay for postoperative analgesia, current practice has focused on a multimodal approach to pain control, including ultrasound-guided blocks with longer acting local anesthetic agents. Non-steroidal anti-inflammatory drugs (NSAIDs), such as meloxicam, are an important class of medications utilized to manage pain in the perioperative period. An additional treatment used in perioperative or postoperative pain relief is Exparel, a bupivacaine (sodium channel blocker) liposomal injectable suspension with a 3-4-day duration of action. The long-acting mechanism and formulation of Exparel consistently has demonstrated decreased opioid use and pain scores in patients undergoing many different surgical procedures. A concern is that pH negatively alters the efficacy of bupivacaine, as in cases of inflamed tissue and acidic fluid pH. For this reason, a combination medication with both meloxicam and bupivacaine has been developed, which normalizes pH and has anti-inflammatory and anti-pain conduction properties. Clinical studies demonstrate that this combination agent can be extremely beneficial in treating postoperative pain. This manuscript summarizes the newest developments with regard to liposomal bupivacaine and the non-steroidal meloxicam, their roles in effective treatment of postoperative pain, contraindications, special considerations of using these medications, and future considerations. HTX-011 pairs up a new extended-release formulation of the local anesthetic bupivacaine with meloxicam, a well-established non-steroidal anti-inflammatory drug (NSAID).

The use of nanosized liposomes from vegetable phospholipids in combination with albumine and some polysaccharides as cryoprotective agents in the course of cryopreservation

It is known that nanosized liposomes from vegetable and animal phospholipids promote survival and functional adequacy of animal cells in the course of cryopreservation. It is also known that albumine and some polysaccharides have membrane-protective properties. In this paper we investigated whether there is a synergism of cryoprotective action between soybean liposomes and macromolecular compounds: albumine, sodium alginate, methylcellulose, carageenan and hyaluronic acid. To determine the cryoprotective effect we carried out cryopreservation of bull semen using a standard procedure in the presence of the substances under investigation. Albumine and sodium alginate demonstrated the most considerable cryoprotective effect in the presence of liposomes. In addition we determined dimensional characteristics of nanoparticles in a liposome suspension without and with sodium alginate and studied the influence of autoclave treatment on the nanoparticle size and cryoprotective effect of the complex. Autoclaving caused enlargement of a small-sized fraction of nanoparticles, supposedly, sodium alginate aggregates. Besides, the autoclaving did not demonstrate any influence on the cryoprotective efficiency of the mixture.

ENCAPSULATION OF ANTITUMOR COPPER COMPLEX INTO LIPOSOMES

To encapsulate a new copper coordination compound drug for triple-negative breast cancer treatment we have developed a new approach. The obtained liposomal suspension is stable up to 2 weeks; successful complex loading is confirmed spectrophotometrically and can be quantified by HPLC.

Improving Topical Skin Delivery of Monocrotaline Via Liposome Gel-based Nanosystems.

In this study, a liposomal gel based on a pH-gradient method was used to increase the skin-layer retention of monocrotaline (MCT) for topical administration. Using the Box-Behnken design, different formulations were designed to form liposome suspensions with optimal encapsulation efficiency (EE%) and stability factor (KE). In order to keep MCT in liposomes and accumulate in skin slowly and selectively, MCT liposome suspensions were engineered into gels. A pH-gradient method was used to prepare liposome suspensions. The optimal formulation of liposome suspensions (encapsulation efficiency: 83.10 ± 0.21%) was as follows: MCT 12 mg, soybean phosphatidyl choline (sbPC) 200 mg, cholesterol (CH) 41 mg, vitamin E (VE) 5 mg, and citric acid buffer solution (CBS) 4.0 10 mL (pH 7.0). The final formulation of liposomal gels consisted of 32 mL liposome suspensions, 4.76 mL deionized water, 0.40 g Carbopol-940, 1.6 g glycerol, 0.04 g methylparaben, and a suitable amount of triethanolamine for pH value adjustment. The results of in vitro drug release showed that MCT in liposomal gels could be released in 12 h constantly in physiological saline as a Ritger-Peppas model. Compared with plain MCT in gel form, liposomal MCT in gel had higher skin retention in vitro. In this study, liposomal gels were formed for greater skin retention of MCT. It is potentially beneficial for reducing toxicities of MCT by topical administration with liposomal gel.

Proliposomes: An Approach for the Development of Stable Liposome

Background: For several years, many attempts have been made for the improvement of liposomal stability. In 1986, Payne et al, introduced the concept of Pro-liposome for liposome preparation in order to avoid physicochemical instability encountered in some liposome suspensions such as aggregation, fusion, hydrolysis, and/or oxidation. Objective: The objective of this review is to focus on different aspects related to Proliposomes, their method of preparation, characterization techniques and pointing out its scope in drug delivery systems. Methods: Proliposomes are a new form of drug delivery systems. They are dry, free-flowing granular products composed of drug and phospholipid which, upon addition of water, disperse to form a multi-lamellar liposomal suspension. Results and Discussion: These Proliposomes are nearly as good as or perhaps better than conventional liposomes. In the present review attempt has been made to briefly explain the concept of Proliposomes with a focus on its components, preparation, characterizations and their field of application. Conclusion: Extensive survey of literatures and collected data suggests that Pro-liposomes are promising drug carriers for the future.

Impact of Sample Concentration on the Determination of Particle Size of Nano Polymer Particles and Nano Liposomes by Dynamic Light Scattering

Determination of particles size is important in pharmaceutical research and manufacturing of drug delivery system in nano scale. This study was carried out to evaluate particles size of nano polymer particles, composed of Eudragit RL 100, and nano liposomes, composed of hydrogenated soy phosphatidylcholine and cholesterol. Dynamic light scaterring was used to determine nano particles size. The results showed that, dilution ratio influenced differently on the determined nanoparticles. Liposomal suspension, which was diluted to count rate less than 170 kcps, had statistically significant larger particle than that, which had greater count rate. Polymer particles, which were diluted to count rate less than 126 had statistically significant larger particles than that, which had greater count rate.&#x0D; Keywords&#x0D; Particle size, nano polymer particle, nano liposomes, dynamic light scattering (DLS).&#x0D; References&#x0D; [1] E.H.M. Sakho, E. Allahyari, O.S. Oluwafemi, S. Thomas, and N. Kalarikkal, Dynamic Light Scattering (DLS) in: Thermal and rheological measurement techniqus for nanometerials characterization, Elsevier, Europe 2017.[2] V.X. Minh, P.T.M. Hue, Applications of nanotechnology and liposomes in Pharmaceuticals and cosmetics, Medical publishing house, Hanoi, 2013 (in Vietnamese).[3] ISO 22412:2017, Particle size analysis - Dynamic light scattering (DLS).[4] J. Panchal, J. Kotarek, E. Marszal, and E.M. Topp, Analyzing Subvisible Particles in Protein Drug Products: a Comparison of Dynamic Light Scattering (DLS) and Resonant Mass Measurement (RMM), AAPS J., 16(3) (2014) 440–451. http://doi.org/ 10.1208/s12248-014-9579-6.[5] A. Chaudhury et al, Lyophilization of cholesterol-free PEGylated liposomes and its impact on drug loading by passive equilibration, Int. J. Pharm., 430(1–2) (2012) 167–175. https://doi.org/10.1016/j.ijpharm.2012.04.036.[6] T. Ishida, H. Harashima, and H. Kiwada, Liposome clearance, Biosci. Rep., 22(2) (2002) 197–224. https://doi.org/10.1023/A:1020134521778.&#x0D; &#x0D;

Nano-scaled Calcium Molybdate Particle Formation on Egg Phosphatidylcholine Liposome Surface

Calcium molybdate nanoparticles were synthesized using a liposome based on egg phosphatidylcholine and cholesterol. The molybdate ion was encapsulated into the liposome, and then a calcium chloride solution was added to the liposome suspension. The molybdenum release kinetics from the liposome to the bulk solution was determined to be 8 ppb h−1. The calcium ion caused aggregation of the liposomes at a higher concentration (>2.5 mM). By using a 1 mM calcium solution, the nanosized calcium molybdate (∼20 nm) precipitated on the liposome surfaces.

Leveraging the Coffee Ring Effect for a Defect-Free Electroformation of Giant Unilamellar Vesicles.

We took advantage of the microflow hydrodynamics in the evaporation of sessile droplets to increase the height uniformity of thin lipid films for the subsequent electroformation of defect-free giant unilamellar vesicles (GUV). By serially casting progressively larger liposome suspension droplets on the same spot of an indium-tin-oxide (ITO) electrode, we managed to leverage the coffee ring effect (CRE) in the evaporation of each droplet to generate a smeared multilayer film of uniform thickness. This multidroplet technique of lipid film formation outperformed the traditional single-droplet deposition, improving the final quality of electroformed GUV samples. The proposed film formation technique constitutes a solvent-free method that results in a dramatic reduction (∼20×) in the appearance of undesirable structures like nonspherical (NSV), multilamellar (MLV), and multivesicular (MVV) vesicles.