Preparation, characterization and evaluation of bufalin liposomes coated with citrus pectin

Nano-engineering of sertraline liposomes using supercritical fluid and optimization of the involved parameters

Sertraline is one of the drugs whose transport from the blood circulation to the brain is severely limited by the blood-brain barrier and it shows low bioavailability (44%). Liposomes can be an effective carrier for this drug and increase bioavailability. In this study, the synthesis of nanometer-sized liposomes containing sertraline hydrochloride is proposed using a technique called supercritical fluid expansion into aqueous solution (ESSAS). In this technique, phospholipid precipitation rates are controlled, and homogeneous liposomes with nanometer-sized dimensions can be created. The operational parameters were optimized using the response surface methodology (pressure drop: 29.9 MPa, collection time: 13.6 min, temperature: 40 °C), which showed that the optimal values for the encapsulation efficiency, mean size, and number of liposomes were 78.4%, 89.5 nm, and 85, respectively. Also, the drug release test showed that it takes 27 h for sertraline to be completely released from the liposomal suspension.

Physicochemical characterization of liposomes produced by ultrasonication and coated with pectin for the coencapsulation of vitamins D3 and B12

Liposomes represent a versatile platform for the coencapsulation of hydrophilic and hydrophobic bioactive compounds, thereby increasing their potential for micronutrient delivery in food products. In this study, vitamins D3 (VD3) and B12 (VB12) were coencapsulated within liposomes produced via ultrasonication using hydrogenated or nonhydrogenated phospholipids. Additionally, pectin was investigated as a coating material for phospholipid vesicles, with the goal of potentially enhancing their stability during storage. The diameters of the uncoated liposomes ranged from 98 to 392 nm, depending on the type of phospholipid used, and all formulations exhibited stability over a 30-day period. Pectin-coated liposomes had diameters ranging from 177 to 236 nm, and their stability was largely influenced by the use of unsaturated phospholipids, with the polysaccharide concentration impacting long-term stability. Coencapsulation of VD3 and VB12 was successfully achieved in both uncoated and coated liposomes, with VD3 demonstrating significantly greater encapsulation efficiency than VB12. Notably, both vitamins were effectively protected from degradation during storage.

Fucoidan coated liposomes loaded with novel antituberculosis agent: preparation, evaluation, and cytotoxicity study

In this article, we described a novel antituberculosis imidazotetrazine derivative designed in fucoidan-coated liposomes to reduce its cytotoxicity and investigate its mucoadhesive properties. Firstly, fucoidan extracted from Ascophyllum nodosum was used for additional stabilization of liposomal suspensions and to give it mucoadhesive properties. PEG-600 and/or Tween-80 were used to increase the shelf life of liposomal suspension. The ratio of the fucoidan: lipids 1:2 was found to be the optimum that produces stable fucoidan-coated liposomes. The particle size of the optimum formulation was 336.3 ± 5.4, the PDI was 0.33, and the zeta potential was -39.6. This size and the practical spherical shape of the particles were confirmed by atomic force microscopy. In addition, the in vitro release profiles from uncoated and fucoidan-coated liposomes revealed significant and faster release compared to free antituberculosis agent. Using the MTT assay test, the fucoidan-coated liposomes exhibited fourteen times lower cytotoxicity (IC50 7.14 ± 0.91 µg/ml) than the free drug (IC50 0.49 ± 0.06). Moreover, the mucoadhesive capabilities of these liposomal formulations were also confirmed using snail mucin, which highlighting their potential use as an effective delivery system for antituberculosis therapy, with notable improvements in dissolution rate and reduced cytotoxicity.

Preparation of pectin-coated and chitosan-coated phenylethanoside liposomes: Studies on characterization, stability, digestion and release behavior

In this paper, the effects of extrusion, ultrasound on physicochemical properties of liposomes were studied, and the liposomes were prepared by ethanol injection combined with extrusion-ultrasound. In addition, the quality of PhGs lips, pectin-coated PhGs lips (P-lips) and chitosan-coated PhGs lips (C-lips) was evaluated by the average particle size, encapsulation efficiency (EE) and other indicators, which indicated that the nanoparticles had been successfully prepared. Compared with extrusion or ultrasonic operation alone, the EEs of ethanol injection combined with extrusion-ultrasonic increased by 8 % and 18 % respectively. Subsequently, transmission electron microscopy, Fourier transform infrared spectroscopy and DSC thermal analysis showed that PhGs in PhGs lips may produce hydrogen bonding forces with phospholipids, and pectin and chitosan in P-lips and C-lips were not only coated on the surface of PhGs lips, but also might have some interaction between them. Cell experiments showed that PhGs lips, P-lips and C-lips can effectively improve the bioavailability of PhGs. In addition, the storage stability of P-lips and C-lips was not significantly improved compared to PhGs lips, but their digestive stability was significantly improved, and the final retention rate in simulated intestinal fluid was about 25 % higher than that of PhGs lips.

Characterizations and effects of pectin-coated nanoliposome loaded with Gijavash (Froriepia subpinnata) extract on the physicochemical properties of cheese

In this study, pectin-coated nanoliposomes containing Gijavash extract were used to formulate cheese and evaluate its shelf life, physicochemical, and sensory aspects. The study used a central composite design with three independent variables to prepare the cheese. The results showed that the optimal particle size, zeta potential, encapsulation efficiency, and DPPH radical antioxidant activity were 201.22 nm, -29.33 mV, 61.87%, and 57.54%, respectively. Adding nanoliposomes with varying extract amounts improved pH and lowered acidity in fortified cheeses. Moisture and lipolysis indices also improved after applying nanoliposomes. Sensory evaluation revealed that sensory acceptance was highest in the cheese with 15% extract. The study suggests that adding pectin-coated nanoliposomes containing Gijavash extract to cheese formulations may create novel products and improve their physicochemical properties.

Application of the Ugi reaction for preparation of submicron capsules based on sugar beet pectin

The Ugi four-component condensation in diluted liposomal suspensions was used to prepare pectin-based submicron capsules. A set of isocyanides and aldehydes was used to optimize the synthesis of capsule shells. Modified sugar beet pectin was selected as a natural polymer with pronounced surface activity to create a capsule shell. At first, liposomal composition was optimized in order to select suitable conditions for capsule formation. Then, the wide set of capsules constructed on modified sugar beet pectin scaffold has been synthesized. The choice was determined by level of substitution degree and possible chemical diversity of the modified surface. Detailed characterization of products has been performed for polysaccharide particles with liposomal core prepared with various processing parameters (concentration, cross-linking components, the density of linkage). The chemical structure, average size, polydispersity index, morphology, stability, and cytotoxicity of obtained particles have been investigated in dependence on the shell content. The obtained submicrometer cross-linked capsules (220-240 nm) with controlled colloidal properties showed high stability and low toxicity. Thus, the proposed carriers have a great potential as sustained drug delivery systems for different administration routes.

Use of sodium alginate coatings to improve bioavailability of liposomes containing DPP-IV inhibitory collagen peptides

Sodium alginate (SA) was used to coat liposomes containing DPP-IV inhibitory collagen peptides to improve their stability and in vitro absorption for intra-oral delivery. The liposome structure as well as entrapment efficiency and DPP-IV inhibitory activity was characterized. The liposome stability was determined by measuring in vitro release rates and their gastrointestinal stability. Transcellular permeability of liposomes was further tested to characterize their permeability in small intestinal epithelial cells. The results showed that the 0.3% SA coating increased the diameter (166.7 nm to 249.9 nm), absolute value of zeta potential (30.2 mV to 40.1 mV) and entrapment efficiency (61.52% to 70.99%) of liposomes. The SA-coated liposomes containing collagen peptides showed enhanced storage stability within one month, gastrointestinal stability increased by 50% in bioavailability, transcellular permeability increased by 18% in transmission percentage, and in vitro release rates reduced by 34%, compared to uncoated liposomes. SA coating liposomes are promising carriers for transporting hydrophilic molecules, may be beneficial for improving nutrient absorption and can protect bioactive compounds from being inactivated in the gastrointestinal tract.

Coating Materials to Increase the Stability of Liposomes

Liposomes carry various compounds with applications in pharmaceutical, food, and cosmetic fields, and the administration route is especially parenteral, oral, or transdermal. Liposomes are used to preserve and release the internal components, thus maintaining the properties of the compounds, the stability and shelf life of the encapsulated products, and their functional benefits. The main problem in obtaining liposomes at the industrial level is their low stability due to fragile phospholipid membranes. To increase the stability of liposomes, phospholipid bilayers have been modified or different coating materials have been developed and studied, both for liposomes with applications in the pharmaceutical field and liposomes in the food field. In the cosmetic field, liposomes need no additional coating because the liposomal formulation is intended to have a fast penetration into the skin. The aim of this review is to provide current knowledge regarding physical and chemical factors that influence stability, coating materials for liposomes with applications in the pharmaceutical and food fields to increase the stability of liposomes containing various sensitive compounds, and absorption of the liposomes and commercial liposomal products obtained through various technologies available on the market.

Pectin coated Nanostructured Lipid Carriers for Targeted Piperine Delivery to Hepatocellular Carcinoma

Piperine (PIP) is a herbal drug with well-known anticancer activity against different types of cancer including hepatocellular carcinoma. However, low aqueous solubility and extensive first-pass metabolism limit its clinical use. In this study, positively charged PIP-loaded nanostructured lipid carriers (PIP-NLCs) were prepared via melt-emulsification and ultra-sonication method followed by pectin coating to get novel pectin-coated NLCs (PIP-P-NLCs) targeting hepatocellular carcinoma. Complete in vitro characterization was performed. In addition, cytotoxicity and cellular uptake of nanosystems in HepG2 cells were evaluated. Finally, in vivo anticancer activity was tested in the diethylnitrosamine-induced hepatocellular carcinoma mice model. Successful pectin coating was confirmed by an increased particle size of PIP-NLCs from 150.28±2.51 nm to 205.24±5.13 nm and revered Zeta potential from 33.34±3.52 mV to -27.63±2.05 mV. Nanosystems had high entrapment efficiency, good stability, spherical shape, and sustained drug release over 24 hours. Targeted P-NLCs enhanced the cytotoxicity and cellular uptake compared to untargeted NLCs. Furthermore, PIP-P-NLCs improved in vivo anticancer effect of PIP as proved by histological examination of liver tissues, suppression of liver enzymes and oxidative stress environment in the liver, and alteration of cell cycle regulators. To conclude, PIP-P-NLCs can act as a promising approach for targeted delivery of PIP to hepatocellular carcinoma.

Pelargonidin-3-O-Glucoside Encapsulated Pectin-Chitosan-Nanoliposomes Recovers Palmitic Acid-Induced Hepatocytes Injury

Pelargonidin-3-O-glucoside (Pg) is a well-known anthocyanin derivative possessing potential biological activity. Nonetheless, the bioactivity of Pg is limited due to instability in the physiological environment. Functionalized nanoliposomes using chitosan and/or pectin coating is an excellent carrier system for nanoencapsulation of food bioactive compounds such as Pg. Therefore, this study aimed to investigate the protective effect of Pg-loaded pectin–chitosan coated nanoliposomes against palmitic acid (PA)-induced hepatocytes injury in L02 cells. Firstly, Pg-loaded pectin–chitosan coated nanoliposomes were characterized using the DLS, HPLC, TEM, and cellular uptake study in L02 cells. Thereafter, we assayed the protective effect against PA-induced lipotoxicity, ROS and O₂^•− generation, mitochondrial dysfunction (MMP), and GSH depletion. Results showed that Pg-loaded nanoliposomes significantly reduced the PA-induced L02 cells toxicity via suppressing ROS production, O₂^•− generation, MMP collapse, and GSH reduction, whereas the free-Pg samples were not effective. On the contrary, the chitosan and/or pectin coated nanoliposomes showed higher results compared to coating-free nanoliposomes. Altogether, the results of our study ensured that Pg-loaded pectin–chitosan coated nanoliposomes was capable of reducing PA-induced hepatocytes injury. Thus, pectin–chitosan coated nanoliposomes can be useful for hepatocellular delivery of hydrophilic compounds with greater biological activity.

Hyaluronic Acid Coated Chitosan Nanoparticles for Insulin Oral Delivery: Fabrication, Characterization and Hypoglycemic Ability

Oral administration of insulin faces multiple biological challenges, such as varied digestive environments, mucin exclusion and low epithelial cells absorption. In the present study, a hyaluronic acid coated chitosan nanoparticle delivery system was fabricated for insulin oral delivery. It is hypothesized that the developed nanoparticles will protect insulin from digestive degradation, promote intestinal epithelial cell absorption and exert strong in vivo hyperglycemic ability. Nanoparticles formulated by chitosan (CS) and sodium tripolyphosphate (TPP) was optimized to form the core nanoparticles (CNP). Hyaluronic acid (HA) was further applied to coat CNP (HCP) to improve stability, reduce enzymatic degradation and promote absorption of insulin. HCP promoted insulin uptake by Caco-2 cells, absorbed less mucin and improved intestinal absorption. Moreover, in vivo test demonstrated that oral administration of insulin-loaded HCP exerts strong and continuous hyperthermia effect (with PA of 13.8%). In summary, HCP is a promising delivery platform for insulin oral administration in terms of protecting insulin during digestion, facilitating its absorption and ultimately promoting its oral bioavailability. This article is protected by copyright. All rights reserved.

An ex Vivo Model Enables Systematic Investigation of the Intestinal Absorption and Transcytosis of Oral Particulate Nanocarriers

Nanoparticulate formulations are being developed toward enhancing the bioavailability of orally administrated biologics. However, the processes mediating particulate carriers' intestinal uptake and transport remains to be fully elucidated. Herein, an optical clearing-based whole tissue mount/imaging strategy was developed to enable high quality microscopic imaging of intestinal specimens. It enabled the distribution of nanoparticles within intestinal villi to be quantitatively analyzed at a cellular level. Two-hundred and fifty nm fluorescent polystyrene nanoparticles were modified with polyethylene glycol (PEG), Concanavalin A (ConA), and pectin to yield mucopenetrating, enterocyte targeting, and mucoadhesive model nanocarriers, respectively. Introducing ConA on the PEGylated nanoparticles significantly increased their uptake in the intestinal epithelium (∼4.16 fold for 200 nm nanoparticle and ∼2.88 fold for 50 nm nanoparticles at 2 h). Moreover, enterocyte targeting mediated the trans-epithelial translocation of 50 nm nanoparticles more efficiently than that of the 200 nm nanoparticles. This new approach provides an efficient methodology to obtain detailed insight into the transcytotic activity of enterocytes as well as the barrier function of the constitutive intestinal mucus. It can be applied to guide the rational design of particulate formulations for more efficient oral biologics delivery.

"Mucus-on-Chip": A new tool to study the dynamic penetration of nanoparticulate drug carriers into mucus

The mucus covering of epithelial tissues presents one significant biological barrier to the uptake and absorption of particulate carriers. Improved understanding of the mechanisms mediating the transport of nanoparticles across such mucus layers would accelerate their development as optimised mucosal drug delivery formulations (e.g. via oral and rectal routes). Herein, an in vitro mucus model ("Mucus-on-Chip") was developed to enable the interaction and transport of functionalised nanoparticles and reconstituted mucus to be quantitatively investigated in real-time. We verified that the diffusion of nanoparticles into mucus is highly dependent on their biointerfacial properties. Muco-inert modification (PEGylation) significantly enhanced the mucopenetration of 50 nm and 200 nm nanoparticles, whereas limited mucopenetration was observed for pectin coated mucoadhesive nanoparticles. Furthermore, this model can be easily adapted to mimic specific physiological mucus environments. Mucus pre-treated with a mucolytic agent displayed reduced barrier function and therefore significantly accelerated mucopenetration of nanoparticles, which was independent of their size and biointerfacial properties. This new "Mucus-on-Chip" methodology provides detailed insight into the dynamics of nanoparticle-mucus interaction, which can be applied to refine the design of particulate formulations for more efficient mucosal drug delivery.

Phyto-drug conjugated nanomaterials enhance apoptotic activity in cancer

Cancer continues to be one of the leading causes of death worldwide and is a major obstacle to increased life expectancy. However, survival has not improved significantly with average cancer standard treatment strategies over the past few decades; survival rates have remained low, with tumor metastasis, adverse drug reactions, and drug resistance. Therefore, substitute therapies are essential to treat this dreadful disease. Recently, research has shown that natural compounds in plants, such as phytochemicals, are extensively exploited for their anticarcinogenic potential. Phytochemicals may show their anticancer activity different cancer cell markers may alter molecular pathways, which promote in cellular events such as cell cycle arrest and apoptosis, regulate antioxidant status, cell proliferation, migration, invasion and toxicity. Although their outstanding anticancer activity, however, their pharmacological budding is hindered by their low aqueous solubility, poor bioavailability, and poor penetration into cells, hepatic disposition, narrow therapeutic index, and rapid uptake by normal tissues. In this situation, nanotechnology has developed novel inventions to increase the potential use of phytochemicals in anticancer therapy. Nanoparticles can improve the solubility and stability of phytochemicals, specific tumor cell/tissue targeting, enhanced cellular uptake, reduction of phytochemicals. Therapeutic doses of phytochemicals for a long time. Additional benefits include better blood stability, multifunctional design of nanocarriers and improvement in countermeasures. This review summarizes the advances in the use of nanoparticles for the treatment of cancer, as well as various nano-drug deliveries of phytochemicals against cancer. In particular, we are introducing several applications of nanoparticles in combination with phyto-drug for the treatment of cancer.

Surface decoration of neohesperidin-loaded nanoliposome using chitosan and pectin for improving stability and controlled release

The aim of this study was to improve the physicochemical stability of neohesperidin (NH) using nanoliposomal encapsulation in association with surface decoration strategy employing chitosan (CH) and pectin (P). Different nanoliposomal systems, i.e. NH-loaded nanoliposome (NH-NL), CH-coated NH-NL (CH-NH-NL), and P-coated CH-NH-NL (P-CH-NH-NL) were characterized through DLS, HPLC, TEM, and FTIR. The results confirmed good encapsulation efficiency (>90%) and successful layer formation with nano-sized and spherical carrier. Both CH-NL and P-CH-NL exhibited better physicochemical stability than NL under storage, thermal, pH, ionic, UV, oxidative, and serum conditions. In vitro mucin adsorption study revealed that CH-NL (60%) was more effective in mucoadhesion followed by P-CH-NL (46%) and NL (41%). Furthermore, P-CH-NL showed better performance in NH retention under different food simulants compared to CH-NH-NL and NH-NL, in which the release was mainly governed by the diffusion process. Thus, the P-CH conjugated nanoliposome could be a promising nano-carrier for neohesperidin.

Engineered Site-specific Vesicular Systems for Colonic Delivery: Trends and Implications

Steering drug-loaded, site-specific, coated lipid vesicles to the target receptor sites have the potential of plummeting adverse effects and improving the pharmacological response in diverse pathologies of the large bowel, especially the colon. Colonic delivery via oral route has its own challenges, often governed by several glitches such as drug degradation or absorption in the upper GIT, instability of proteins/peptides due to high molecular weight, and peptidase activity in the stomach. Consequently, colon-specific coated liposomal systems (CSLS) offer a potential alternate for not only site-specificity, but protection from proteolytic activity, and prolonged residence time for greater systemic bioavailability. On the other hand, liposomal delivery via the oral route is also cumbersome owing to several barriers such as instability in GIT, difficulty in crossing membranes, and issues related to production at the pilot scale. New advancements in the field of CSLS have successfully improved the stability and permeability of liposomes for oral delivery via modulating the compositions of lipid bilayers, adding polymers or ligands. Despite this ostensible propitiousness, no commercial oral CSLS has advanced from bench to bedside for targeted delivery to the colon as yet. Nevertheless, CSLS has quite fascinated the manufacturers owing to its potential industrial viability, simplistic and low-cost design. Hence, this review aims to decipher the convolutions involved in the engineering process of industrially viable CSLS for colonic delivery.

Improving the physicochemical stability and functionality of nanoliposome using green polymer for the delivery of pelargonidin-3-O-glucoside

This study aimed to improve the physicochemical stability of nanoliposome (NL) with enhanced functionality for the delivery of Pelargonidin-3-O-glucoside (P3G) using biopolymers, i.e. chitosan (CH) and pectin (P). In this study, we successfully developed stabilized liposomal carriers, i.e. CH-conjugated NL (CH-NL) and P-conjugated CH-NL (P-CH-NL) using an optimum concentration of CH (0.6 wt%) and P (0.5 wt%). Results revealed that P-CH-NL had better physical stability to salt and pH with maximum P3G retention (>97%) under oxidative, thermal, and UV conditions. Nanoliposomes were more stable under refrigerated-storage and ensured high P3G retention (>96%). In vitro mucoadhesion study revealed that CH-NL had better mucin adsorption efficiency (59.72%) followed by P-CH-NL and NL. Furthermore, CH-NL and P-CH-NL alternatively had better stability to serum than NL. Taken together, the stabilization of nanoliposome using chitosan and pectin can be a promising approach for the delivery of hydrophilic compounds in association with enhanced stability and functionality.

Recent Advances in Vaginal Delivery for the Treatment of Vulvovaginal Candidiasis

BACKGROUND

Vulvovaginal candidiasis (VVC) is a common vaginal infection caused by candida species, affecting 70% of the women. It may occur due to the imbalance in the vaginal micro- biodata, pregnancy, diabetes, use of antibiotics, frequent sexual activities or AIDS.

AIM

The main aim of this review is to provide overview about different vaginal delivery systems for the administration of antifungal agents like conventional, mucoadhesive and muco-penetrating delivery systems.

METHOD

The conventional delivery systems available have limited efficacy due to the less residence time and adverse effects. In order to overcome these issues, a delivery system with mucoadhesive and muco-penetrating properties is required. Mucoadhesive polymers have excellent binding properties with mucin and thus increasing residence time. On the other hand, muco-penetrating polymers transport the antifungal agents across the mucus layer.

RESULTS

This review summarizes the pathophysiology of VVC along with novel delivery systems for the treatment of infection through mucoadhesive and muco-penetrating approaches. Surface modifications of nano/ microparticles with mucoadhesive or muco-penetrating particles may provide delivery systems with improved therapeutic efficacy.

CONCLUSION

Based on the available data, conventional and mucoadhesive drug delivery systems have some limitations, they still require improvement/ development for safe and effective delivery of antifungal agents.

Formulation and Characterization of Sertaconazole Nitrate Mucoadhesive Liposomes for Vaginal Candidiasis

Purpose

The aim of this study is to develop efficient localized therapy of sertaconazole nitrate for the treatment of vaginal candidiasis.

Methods

Sertaconazole nitrate-loaded cationic liposomes were prepared by thin-film hydration method and coated with different concentrations of pectin (0.05%, 0.1% and 0.2%) to develop mucoadhesive liposomes. The formulated mucoadhesive vesicles were characterized in terms of morphology, entrapment efficiency, particle size, zeta value, mucoadhesive properties and drug release. The selected formula was incorporated into a gel base and further characterized by an ex vivo permeation study in comparison with conventional sertaconazole gel. Also, the in vivo study was performed to assess the efficacy of sertaconazole mucoadhesive liposomal gel in treating rats with vaginal candidiasis.

Results

The mucoadhesive liposomes were spherical. Coating liposomes with pectin results in increased entrapment efficiency and particle size compared with uncoated vesicles. On the contrary, zeta values were reduced upon coating liposomes with pectin indicating efficient coating of liposomes with pectin. Mucoadhesive liposomes showed a more prolonged and sustained drug release compared with uncoated liposomes. Ex vivo study results showed that mucoadhesive liposomal gel increased sertaconazole tissue retention and reduced drug tissue penetration. In the invivo study, the mucoadhesive liposomal gel showed a significant reduction in the microbial count with a subsequent reduction in inflammatory responses with the lowest histopathological change compared with conventional gel.

Conclusion

The study confirmed the potentiality of employing mucoadhesive liposomes as a successful carrier for the vaginal delivery of antifungal drugs.

Bufalin-Loaded PEGylated Liposomes: Antitumor Efficacy, Acute Toxicity, and Tissue Distribution

Bufalin, derived from Venenum Bufonis, exerts antitumor effects but has low bioavailability and adverse effects when administered as a single agent. The purpose of this study was to evaluate the physical and chemical properties, antitumor efficacy, general pharmacology, acute toxicity, and tissue distribution profile of bufalin-loaded PEGylated liposomes (BF/PEG-LP), which were prepared in a previous study. To evaluate the safety of the preparation, a red blood cell hemolysis test was performed, which indicated that the hemolysis rate of BF/PEG-LP was significantly lower than that of bufalin alone. Cell viability assay revealed that the blank liposomes were nontoxic. In an in vitro experiment, BF/PEG-LP dose-dependently induced the apoptosis of HepG2, HCT116, A549, and U251 cancer cells, with half-maximal inhibitory concentration (IC₅₀) values of 21.40 ± 2.39, 21.00 ± 3.34, 43.39 ± 6.43, and 31.14 ± 2.58 ng/mL, respectively, at 24 h. Tumor xenograft experiments in nude mice showed that BF/PEG-LP significantly inhibited the growth of U251 cells. Pharmacological evaluation revealed that BF/PEG-LP impacted the general behavior, independent activities, and coordination of mice after a week of administration compared with those of mice in the control group. In an acute toxicity test, the median lethal concentration (LD₅₀) of BF and BF/PEG-LP in mice was 0.156 and 3.03 mg/kg, respectively. Tissue distribution profiles showed that the BF concentration in brain tissue was 20% higher, whereas that in heart tissue was 30% lower when BF/PEG-LP was administered to mice compared with BF. Thus, BF/PEG-LP exhibited lower hemolysis and cytotoxicity and improved pharmacokinetic and antitumor properties compared with bufalin alone, indicating its potential for future pharmacological application, particularly for glioma treatment.

Long-circulating and fusogenic liposomes loaded with a glucoevatromonoside derivative induce potent antitumor response

Cancer is an important public health problem, being one of the leading causes of death worldwide. Most antineoplastic agents cause severe toxic effects and some types of cancer do not respond or are resistant to the existing pharmacotherapy, necessitating the research and development of new therapeutic strategies. Cardenolides have shown significant antitumor activity due to their ability to inhibit the Na⁺K⁺ATPase enzyme, and the expression of this enzyme is increased in tumor cells. Glucoevatromonoside containing peracetylated glucose hydroxyl groups (GEVPG) is a cardenolide derivative that has low solubility in aqueous media, which constitutes a barrier to its potential biological applications. In this context, the use of liposomes represents a promising strategy to deliver GEVPG, thus allowing its intravenous administration. In this study, long-circulating and fusogenic liposomes containing GEVPG (SpHL-GEVPG) were developed, and their chemical and physicochemical properties were evaluated. SpHL-GEVPG presented adequate properties, including a mean diameter of 182.2 ± 2.7 nm, a polydispersity index equal to 0.36 ± 0.03, a zeta potential of -2.37 ± 0.31 mV, and a GEVPG entrapment of 0.38 ± 0.04 mg/mL. Moreover, this formulation showed a good stability after having been stored for 30 days at 4 °C. The cytotoxic studies against breast (MDA-MB-231, MCF-7, and SKBR-3) and lung (A549) cancer cell lines demonstrated that SpHL-GEVPG treatment significantly reduced the cell viability. In addition, the SpHL-GEVPG formulation presented a good selectivity toward these cancer cells. The evaluation of the therapeutic efficacy of the treatment with SpHL-GEVPG showed a potent anticancer effect in an A549 human lung cancer xenograft model. SpHL-GEVPG administered at doses of 1.0 and 2.0 mg/kg (i.v.) induced antitumor effect comparable to paclitaxel given at dose of 10 mg/kg (i.v.) to mice. Therefore, the results of the present work indicate the potential applicability of SpHL-GEVPG as a new anticancer formulation.

In situ phase transition of microemulsions for parenteral injection yielding lyotropic liquid crystalline carriers of the antitumor drug bufalin

In this work, we used the small angle X-ray scattering (SAXS) method for controlled preparation of in situ forming sustained-release carriers for the antitumor drug bufalin (BUF), which has very poor solubility and a considerable cardiotoxicity in a non-encapsulated state. To that aim, we exploited the pseudo-ternary phase diagram of an oil(O)/surfactant(S)/water(W) system containing medium chain capric/caprylic triglycerides (MCT) and a co-surfactant blend of Macrogol (15)-hydroxystearate (Solutol HS 15) and sorbitan monooleate (Span 80). Two compositions with different oil contents (sample B and C) were selected from the microemulsion region of the phase diagram in order to study the effect of the aqueous environment on their structural behavior. A phase transition from a microemulsion (ME) to a liquid crystalline phase (LC) was established by SAXS upon progressive dilution. The drug bufalin (BUF) was encapsulated in the microemulsions with low viscosity, whereas the release of the drug occurred from the in situ generated lamellar liquid crystalline structures. The formulations were characterized by SAXS, dynamic light scattering (DLS), cryogenic transmission electron microscopy (Cryo-TEM), rheology, drug loading and encapsulation efficiency, and in vitro release profiles. A correlation was suggested between the structures of the in situ phase-transition formed LCME formulations, the differences in their viscosities and drug release profiles. The performed cytotoxicity, cell apoptosis and pharmacokinetic experiments showed an enhanced bioavailability of BUF after encapsulation. These results suggest potential clinical applications for the obtained safe in situ phase-transition sustained-release formulations of BUF.

Nanotechnology application to local anaesthesia (LA)

Several advancements have been made on the exact release of local anaesthetics formulation and its efficiency at inducing motor and sensory block for an extended time has been harnessed in clinical practice. The use of sustained release formulations delivers analgesia for a lengthier period of time with one administration, thereby reducing complications that usually arise with administration of conventional analgesia. In addition, controlled release of an anaesthetic drug is said to prevent overdosing, reduced side effects, especially cardiotoxicity, neurotoxicity and tissue lesions. The use of nanotechnology knowledge via liposomal formulation has recorded high successful results in pain control and quick patient recovery.

Mucoadhesive vs. mucopenetrating particulate drug delivery

Mucus layer is a hydrophilic absorption barrier found in various regions of the body. The use of particulate delivery systems showed potential in drug delivery to mucosal membranes by either prolonging drug residence time at the absorption or target membrane or promoting permeation of particles across mucus gel layer to directly reach underlying epithelium. Mucoadhesive particles (MAP) are advantageous for delivering drug molecules to various mucosal membranes including eyes, oral cavity, bladder and vagina by prolonging drug residence time on those membranes. In contrast, a broader particle distribution and deeper penetration of the mucus gel layer are accomplished by mucopenetrating particles (MPP) especially in the gastrointestinal tract. Based on the available literature in particular dealing with in vivo results none of both systems (MAP and MPP) seems to be advantageous over the other. The choice of system primarily depends on the therapeutic target and peculiar properties of the target mucosa including thickness of the mucus gel layer, mucus turnover rate and water movement within the mucus. Future trends are heading in the direction of combining both systems to one i.e. mucoadhesive and mucopenetrating properties on the same particles.

Oral Delivery of Bovine Lactoferrin Using Pectin- and Chitosan-Modified Liposomes and Solid Lipid Particles: Improvement of Stability of Lactoferrin

A critical problem associated with delivery of bovine lactoferrin (bLf) by the oral route is low bioavailability, which is derived from the enzymatic degradation in the gastrointestinal tract and poor permeation across the intestinal epitheliums. Particulate carrier systems have been identified to protect bLf against proteolysis via encapsulation. This study aimed to evaluate the physico-chemical stability of bLf-loaded liposomes and solid lipid particles (SLPs) modified by pectin and chitosan when exposed to various stress conditions. Transmission electron microscopy results showed liposomes and SLPs had a classic shell-core structure with polymer layers surrounded on surface, but the structure appeared to be partially broken after digestion in simulated intestinal fluid (SIF). Although HPLC and sodium dodecyl sulphate-polyacrylamide gel electrophoresis methods qualitatively and quantitatively described either liposomes or SLPs could retain intact bLf against proteolysis in SIF to some extent, all liposome formulations showed rapid rate of lipolysis mediated by pancreatic enzymes. On the other hand, all SLP formulations showed higher heat resistance and greater electrolyte tolerance compared to liposome formulations. After 180 days storage time, liposome-loaded bLf was completely degraded, whereas almost 30% of intact bLf still remained in SLP formulations. Overall, SLPs are considered as primary choice for oral bLf delivery.