The use of PEGylated liposomes to prolong the circulation lifetime of salvianolic acid B

Enhancement of hepatoprotective activity of limonin from citrus seeds against acetaminophen-induced liver injury by HSCCC purification and liposomal encapsulation

Limonin is a natural tetracyclic triterpenoid compound in citrus seeds that presents hepatoprotective effects but is often discarded as agricultural waste because of its low content and low solubility. Herein, limonin with high purity (98.11%) from citrus seeds was obtained via purification by high-speed counter-current chromatography (HSCCC) and recrystallization. Limonin-loaded liposomes (Lip-LM) prepared by thin film hydration and high pressure homogenization method to enhance its solubility and hepatoprotective effect on APAP-induced liver injury (AILI). Lip-LM appeared as lipid nanoparticles under a transmission electron microscope, and showed well dispersed nano-scale size (69.04 ± 0.42 nm), high encapsulation efficiency (93.67% ± 2.51%), sustained release, fine stability. Lip-LM also exhibited significantly better hepatoprotective activity on AILI than free limonin in vivo. In summary, Lip-LM might be used as a potential hepatoprotective agent in the form of dietary supplement and provide an effective strategy to improve the potential value of citrus seeds.

Enhanced anti-malarial efficacy of mefloquine delivered via cationic liposome in a murine model of experimental cerebral malaria

Malaria is a longstanding global health challenge that continues to afflict over 90 countries located in tropical and subtropical regions of the globe. The rise of drug-resistant malarial parasites has curtailed the therapeutic efficacy of a number of once-effective anti-malarials, including mefloquine. In the present study, we have taken advantage of drug encapsulation approach to elevate the anti-malarial potential of mefloquine. Encouragingly, our findings unveil that liposomal formulations of mefloquine outperform equivalent doses of free mefloquine, both in laboratory cultures and in a murine model of malaria. Intriguingly, a cationic liposomal mefloquine formulation, administered at four successive doses of 3 mg/kg body weight, achieves complete resolution of cerebral malaria in the murine model while avoiding noticeable toxic repercussions. Altogether, our study furnishes pre-clinical validation for a therapeutic strategy that can remarkably enhance the drug efficacy, offering a revitalizing solution for failing anti-malarials.

Extending dual-targeting upper-limit in liposomal delivery of lithospermic acid B for Alzheimer's mitochondrial revitalization

Mitochondrial dysfunction is a pivotal event in Alzheimer's disease (AD) pathogenesis. Lithospermic acid B (LA) has shown promise in safeguarding mitochondria, yet the underlying mechanism remains elusive. Here, we present evidence that LA rejuvenated AD-related mitochondrial pool by co-activating mitophagy and mitochondria biogenesis via PINK1/LC3B/P62 and PGC-1α/Nrf2. To advance in vivo application, hydrophilic LA was encapsulated in liposome (MT-LIP@LA) composed of D-mannosamine-cholesterol/DSPE-PEG2000-Tet1/lecithin (molar ratio, 3:0.3:10) for cascaded brain-neuron targeting. MT-LIP demonstrated 4.3-fold enhanced brain accumulation (2.57%dose/g-brain) than LIP (0.60%dose/g-brain) and precisely targeted neurons at AD lesion sites. Mechanism studies unraveled factors contributing to the preeminent brain targeting ability of MT-LIP: (1) high-density modified mannose efficiently binds to glucose transporter 1 (GLUT1) on blood-brain barrier (BBB); (2) prone to trafficking towards caveolin-Golgi pathway during transcytosis. This augmented therapeutic platform efficiently restored mitochondrial health, prevented neurodegeneration, and ameliorated memory deficits in 3 × Tg-AD transgenic mice. Our studies revealed the underlying pharmacological mechanism of LA and provided a concise but efficient platform for neuronal mitochondria quality control in vivo.

Salvianolic acid B-loaded polydopamine-modified hollow mesoporous organic silica nanoparticles for treatment of breast cancer metastasis via suppressing cancer-associated fibroblasts

OBJECTIVE

Drug Delivery System was constructed using dopamine-coated organic-inorganic hybrid hollow mesoporous organic silica nanoparticles (HMON-PDA) as drug carriers and salvianolic acid B (SAB) as a model drug. Then, we further investigated whether it can inhibit lung metastasis of breast cancer by inhibiting cancer-associated fibroblasts (CAFs).

METHODS

The organic-inorganic hybrid hollow mesoporous organic silica nanoparticles (HMON) were prepared. The particle size, zeta potential, and polydispersion coefficient were characterized. High-performance liquid chromatography was used to determine the effect of different feed ratios of HMON and SAB on drug loading rate. Then, SAB-loaded HMON were modified by polydopamine, which is called SAB@HMON-PDA. Cell viability was detected by MTT assay. The migration of 4T1 cells was investigated by wound healing experiment, and the invasion of 4T1 cells was detected by the transwell method. Finally, the mouse breast cancer lung metastasis models were used to explore whether SAB@HMON-PDA can inhibit lung metastasis of breast cancer by inhibiting CAFs.

RESULTS

The obtained nanoparticles have hollow spherical structure. The average particle sizes of HMON, SAB@HMON, and SAB@HMON-PDA were 143.5 ± 0.03, 138.3 ± 0.02, and 172.3 ± 0.18 nm, respectively. The zeta potentials were -44.33±0.15, -41.4 ± 1.30, and -24.13±0.47 mV, respectively. When the ratio of HMON to SAB was 2:1, the drug loading rate reached (18.37±0.04)%. In addition, the prepared SAB@HMON-PDA responded to release SAB under acidic and GSH conditions. The prepared SAB@HMON-PDA could inhibit the migration and invasion of 4T1 cells. The results showed that SAB@HMON-PDA and SAB could inhibit lung metastasis of breast cancer in mice, and SAB@HMON-PDA had a more significant inhibitory effect than SAB.

CONCLUSION

We successfully prepared SAB@HMON-PDA with the dual response of pH and GSH. SAB@HMON-PDA can inhibit the migration and invasion of 4T1 cells, and the effect is more significant than free SAB. This inhibitory effect may be related to the inhibition of CAFs. In vivo experiments demonstrated that SAB@HMON-PDA can inhibit lung metastasis of breast cancer by inhibiting CAFs, and its effect was more significant than that of free SAB.

Liposomes-Based Drug Delivery Systems of Anti-Biofilm Agents to Combat Bacterial Biofilm Formation

All currently approved antibiotics are being met by some degree of resistance by the bacteria they target. Biofilm formation is one of the crucial enablers of bacterial resistance, making it an important bacterial process to target for overcoming antibiotic resistance. Accordingly, several drug delivery systems that target biofilm formation have been developed. One of these systems is based on lipid-based nanocarriers (liposomes), which have shown strong efficacy against biofilms of bacterial pathogens. Liposomes come in various types, namely conventional (charged or neutral), stimuli-responsive, deformable, targeted, and stealth. This paper reviews studies employing liposomal formulations against biofilms of medically salient gram-negative and gram-positive bacterial species reported recently. When it comes to gram-negative species, liposomal formulations of various types were reported to be efficacious against Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii, and members of the genera Klebsiella, Salmonella, Aeromonas, Serratia, Porphyromonas, and Prevotella. A range of liposomal formulations were also effective against gram-positive biofilms, including mostly biofilms of Staphylococcal strains, namely Staphylococcus aureus, Staphylococcus epidermidis, and Staphylococcus saprophyticus subspecies bovis, followed by Streptococcal strains (pneumonia, oralis, and mutans), Cutibacterium acnes, Bacillus subtilis, Mycobacterium avium, Mycobacterium avium subsp. hominissuis, Mycobacterium abscessus, and Listeria monocytogenes biofilms. This review outlines the benefits and limitations of using liposomal formulations as means to combat different multidrug-resistant bacteria, urging the investigation of the effects of bacterial gram-stain on liposomal efficiency and the inclusion of pathogenic bacterial strains previously unstudied.

Time-dependent biodistribution profiles and reaction of polyethylene glycol-coated iron oxide nanoclusters in the spleen after intravenous injection in the mice

Polyethylene glycol (PEG) is widely used polymer in the field of pharmaceutics, particularly in which related to drug delivery systems (DDS). Surface coating of the nanoparticles (NPs) with PEG (i.e. pegylation) adds novel characteristics that make their use in vivo more effective with lower cytotoxicity. The biodistribution profiles, reaction, and fate of PEG-coated NPs in vivo still unclear and need more detailed studies. Here in this study, we prepared PEG-coated iron oxide nanoclusters (PEG-coated IONCs) to investigate their biodistribution profiles and reactions in spleen after intravenous injection time-dependently. Using Prussian blue staining method as specific histochemical reaction for iron detection in the tissues, the PEG-coated IONCs were observed in a higher ratio in spleen red pulp after 1 day of injection but decreased time-dependently after 10 days and 20 days. Interestingly, PEG-coated IONCs moved from red pulp into the white pulp specially after 20 days of injection. After long time exposure (20 days), higher amount of PEG-coated IONCs was observed in the center of spleen white pulp follicle. Using histological staining, the reaction of PEG-coated IONCs with splenocytes or immune cells induced cellular abnormalities such as, nucleic acid damages, induction of megakaryocytes number, and sever vacuolation in the white pulp area specially after 20 days of injection. Histochemically, the localization of PEG-coated IONCs in the splenic parenchyma induced the level of the collagen fibers particularly after 1 day and 10 days of injection. Interestingly, cellular abnormalities in the splenic red pulp as well as collagen levels decreased after 20 days of injection due to the clearance of PEG-coated IONCs from this area. This data indicated that cytotoxicity produced by the reaction of PEG-coated IONCs in the spleen are reversible specially after 20 days of in the intravenous injection. Understanding the detailed mechanism of the fate and reaction of the coated nanomaterials after intravenous injection is important to design effective and safe DDS based NPs.

Nano-delivery of salvianolic acid B induces the quiescence of tumor-associated fibroblasts via interfering with TGF-β1/Smad signaling to facilitate chemo- and immunotherapy in desmoplastic tumor

As the key stromal cells that mediate the desmoplastic reaction, tumor-associated fibroblasts (TAFs) play a critical role in the limited nanoparticle penetration and suppressive immune tumor microenvironment. Herein, we found that salvianolic acid B-loaded PEGylated liposomes (PEG-SAB-Lip) can interfere with the activation of TAFs by inhibiting the secretion of TGF-β1. After inhibiting the activation of TAFs, collagen deposition in tumors was reduced, and the penetration of nanoparticles in tumors was enhanced. The results of RT-qPCR and immunofluorescence staining showed the high expression of Th1 cytokines and chemokines (CXCL9 and CXCL10) and the recruitment of CD4⁺, CD8⁺ T cells, and M1 macrophages in the tumor area. At the same time, the low expression of Th2 cytokine and chemokine CXCL13, as well as the decrease of MDSCs, Tregs, and M2 macrophages were also observed in the tumor area. These results were related to the inactivation of TAFs. The combined treatment of PEG-SAB-Lip and docetaxel-loaded PEG-modified liposomes (PEG-DTX-Lip) can significantly inhibit tumor growth. Moreover, PEG-SAB-Lip further inhibited tumor metastasis to the lung. Therefore, our results showed that PEG-SAB-Lip can remodel the tumor microenvironment and improve the efficacy of nanoparticles.

Liposomes and Extracellular Vesicles as Drug Delivery Systems: A Comparison of Composition, Pharmacokinetics, and Functionalization

Over the past decades, lipid-based nanoparticle drug delivery systems (DDS) have caught the attention of researchers worldwide, encouraging the field to rapidly develop improved ways for effective drug delivery. One of the most prominent examples is liposomes, which are spherical shaped artificial vesicles composed of lipid bilayers and able to encapsulate both hydrophilic and hydrophobic materials. At the same time, biological nanoparticles naturally secreted by cells, called extracellular vesicles (EVs), have emerged as promising more complex biocompatible DDS. In this review paper, the differences and similarities in the composition of both vesicles are evaluated, and critical mediators that affect their pharmacokinetics are elucidate. Different strategies that have been assessed to tweak the pharmacokinetics of both liposomes and EVs are explored, detailing the effects on circulation time, targeting capacity, and cytoplasmic delivery of therapeutic cargo. Finally, whether a hybrid system, consisting of a combination of only the critical constituents of both vesicles, could offer the best of both worlds is discussed. Through these topics, novel leads for further research are provided and, more importantly, gain insight in what the liposome field and the EV field can learn from each other.

Liver Targeting of Daclatasvir via Tailoring Sterically Stabilized Bilosomes: Fabrication, Comparative In Vitro/In Vivo Appraisal and Biodistribution Studies

INTRODUCTION

Hepatitis C virus (HCV) is a significant public health concern that threatens millions of individuals worldwide. Daclatasvir (DAC) is a promising direct-acting antiviral approved for treating HCV infection around the world. The goal of this study was to encapsulate DAC into novel polyethylene glycol (PEG) decorated bilosomes (PEG-BILS) to achieve enhanced drug delivery to the liver.

METHODS

DAC-loaded BILS were primed by a thin film hydrating technique. The study of the impact of various formulation variables on the properties of BILS and selection of the optimal formulation was generated using Design-Expert® software. The optimum preparation was then pegylated via the incorporation of PEG-6-stearate (5% w/w, with respect to the lipid phase).

RESULTS

The optimum PEG-BILS formulation, containing PL:SDC ratio (5:1), 5 mg cholesterol, and 30 min sonication, yielded spherical vesicles in the nanoscale (200±15.2 nm), elevated percent of entrapment efficiency (95.5±7.77%), and a sustained release profile of DAC with 35.11±2.3% release. In vivo and drug distribution studies revealed an enhanced hepatocellular delivery of DAC-loaded PEG-BILS compared to DAC-unPEG-BILS and DAC suspension, where DAC-PEG-BILS achieved 1.19- and 1.54 times the AUC0-24 of DAC-unPEG-BILS and DAC suspension, respectively. Compared with DAC-unPEG-BILS and DAC suspension, DAC-PEG-BILS delivered about 2 and 3 times higher DAC into the liver, respectively.

CONCLUSION

The innovative encapsulation of DAC-PEG-BILS has a great potential for liver targeting.

Detection and monitoring of the neuroprotective behavior of curcumin micelles based on an AIEgen probe

In recent years, the role of mitochondrial injury in the pathogenesis of Alzheimer's disease (AD) has attracted extensive attention. Studies have shown that curcumin (Cur) can protect nerve cells from beta-amyloid (Aβ)-induced mitochondrial damage. However, natural Cur encounters limited application due to its poor biocompatibility and bioavailability. To improve the solubility and biocompatibility of natural Cur, we prepared water-soluble curcumin micelles (CurM). Furthermore, the mitochondria-specific aggregation-induced emission (AIE) probe (TPE-Ph-In) was employed to observe the protective effect of CurM on the damage of mitochondrial morphology, distribution, and membrane potential caused by Aβ. Results showed that CurM had higher solubility, stronger stability and retention effect, and better cellular uptake than that of natural Cur. Furthermore, the inhibitory effects of CurM on mitochondrial morphology, distribution, and membrane potential damage induced by Aβ25-35 were observed utilizing TPE-Ph-In as an indicator of mitochondrial morphology and membrane potential. Thus, this method provides a useful strategy for experimental research and clinical treatment of AD with mitochondrial damage as the pathogenic mechanism.

Utilization of Lipid-based Nanoparticles to Improve the Therapeutic Benefits of Bortezomib

Cancer is a condition where there is an uncontrolled growth of cells resulting in high mortality. It is the second most frequent cause of death worldwide. Bortezomib (BTZ) is a Proteasome Inhibitor (PI) that is used for the treatment of a variety of cancers. It is the first PI that has received the approval of the US Food and Drug Administration (FDA) to treat mantle cell lymphoma and multiple myeloma. High incidence of sideeffects, limited dose, low water solubility, fast clearance, and drug resistance are the significant limitations of BTZ. Therefore, various drug delivery systems have been tried to overcome these limitations of BTZ in cancer therapy. Nanotechnology can potentially enhance the aqueous solubility of BTZ, increase its bioavailability, and control the release of BTZ at the site of administration. The lipid-based nanocarriers, such as liposomes, solid lipid NPs, and microemulsions, are some of the developments in nanotechnology, which could potentially enhance the therapeutic benefits of BTZ.

Chemical and pharmacological research on the polyphenol acids isolated from Danshen: A review of salvianolic acids

Danshen, the dried root of Salvia miltiorrhiza Bge, is a common medicinal herb in Traditional Chinese Medicine, which has been used for the treatment of a number of diseases for thousands of years. More than 2000 years ago, the Chinese early pharmacy monograph "Shennong Materia Medica" recorded that Danshen could be used for the treatment of gastrointestinal diseases, cardiovascular diseases, certain gynecological diseases, etc. Since then, Danshen has been widely used clinically in many different prescriptions for many different diseases, especially for the treatment of cardiovascular diseases. Nowadays, many pharmacological studies about the water-soluble components from Danshen have been reported, especially salvianolic acids. It turned out that salvianolic acids showed strong anti-lipid peroxidation and anti-thrombic activities, and among them, SalAA and SalAB were the most potent. This review focused on the achievements in research of salvianolic acids regarding their bioactivities and pharmacological effects. These studies not only shed light on the water-soluble active components of Danshen and their mechanisms at the molecular level, but also provided theoretical information for the development of new medicines from Danshen for the treatment of cardiovascular and cerebrovascular diseases, inflammatory diseases, metabolic diseases, etc.

Phytosomes with Persimmon (Diospyros kaki L.) Extract: Preparation and Preliminary Demonstration of In Vivo Tolerability

Persimmon (Diospyros kaki L.), a fruit rich in phenolic compounds (PCs), has been considered effective in mitigating oxidative damage induced by an excess of reactive oxygen species. Due to large molecular weight and intrinsic instability in some physiological fluids, PCs’ passage through biological membranes is very limited. Carriers like phytosomes are promising systems to optimize oral absorption of encapsulated extracts. This work prepared and fully characterized phytosomes containing bioactive phenolic extracts from persimmon in terms of size, surface charge, encapsulation efficiency and stability over six months. These phytosomes were orally dosed to Wistar rats during a 15-day period. Afterwards, haematological and biochemical analyses were performed. Monodisperse phytosomes were successfully prepared, with size less than 300nm (PI < 0.3) and high encapsulation efficiency (97.4%) of PCs. In contrast to free extract, extract-loaded phytosomes had higher antioxidant activity after 6 months storage. Oral administration of extract-loaded phytosomes and free extract did not lead to lipidic profile changes and were within referenced normal ranges, as well as glycaemia levels and urine parameters. The results highlighted the potential of persimmon PCs as food supplements or pharmacological tools, suggesting a promising and safe phytosomal formulation containing bioactive agents of persimmon that could lead to health benefits.

Delivery of phytochemicals by liposome cargos: recent progress, challenges and opportunities

Bio-availability is a major concern in delivery of dietary phytochemicals for better bio-efficacy. The reduced bio-availability of food bioactive compounds is evident due to degradation during human digestion process which involves liberation, absorption, distribution, metabolism and elimination. The bio-efficacy of any nutrient can be increased by increasing bio-availability. Different technologies are available for engineered efficient delivery systems; still many challenges remain with advancement of delivery systems. The ease of preparedness and adaptability of liposomes has resulted in wide-range of applicability and acceptability in scientific field, especially as delivery vehicles. In view, of properties like biocompatibility and biodegradability, liposomes have been modified with different usable methodologies for delivery of phytochemicals. The aim of this review is to abridge liposomes, methods of preparation, their application as delivery cargo in dietary phytochemicals, result of using different preparation techniques on properties.

Peripheral nerve targeting by procaine-conjugated ribavirin-loaded dual drug nanovesicle

AIM

Procaine that is able to reach the peripheral nervous system (PNS) was conjugated as a ligand with lipid nanovesicle and loaded with ribavirin (a broad spectrum antiviral drug incapable of entering the PNS on its own) to target the PNS with a dual-drug effect.

MATERIALS & METHODS

Different physicochemical characterizations, γ-scintigraphy and electromyography of the developed nanovesicle were conducted.

RESULTS

Marked capability of the optimized radiolabeled formulation to target PNS was observed in rats. Electromyography signals were reduced after treatment with the formulation on conscious rats.

CONCLUSION

The developed nanocarrier can deliver drug successfully at the PNS and reduce excitation of the nerve and thus give a better therapeutic option for treatment of various diseases and disorders of the PNS.

Developments in drug delivery of bioactive alkaloids derived from traditional Chinese medicine

The bioactive alkaloids (e.g. vincristine, hydroxycamptothecin, ligustrazine, and so on) from traditional Chinese medicine (TCM) have exerted potent efficacies (e.g. anti-tumor, anti-inflammation, immunosuppression, etc.). However, a series of undesirable physicochemical properties (like low solubility and weak stability) and baneful pharmacokinetic (PK) profiles (e.g. low bioavailability, short half time, rapid clearance, etc.) have severely restricted their applications in clinic. In addition, some side effects (like cumulative toxicities caused by high-frequency administration and their own toxicities) have recently been reported and also confined their clinical uses. Therefore, developments in drug delivery of such alkaloids are of significance in improving their drug-like properties and, thus, treatment efficiencies in clinic. Strategies, including (i) specific delivery via liposomes; (ii) sustained delivery via nanoparticles, gels, and emulsions; and (iii) transdermal delivery via ethosomes, solid lipid nanoparticles, and penetrating enhancers, have been reported to improve the pharmacokinetic and physicochemical characters of problematic TCM alkaloids, decline their adverse effects, and thus, boost their curative efficacies. In this review, the recent reports in this field were comprehensively summarized with the aim of providing an informative reference for relevant readers.

Antibody-modified liposomes for tumor-targeting delivery of timosaponin AIII

Introduction

Timosaponin AIII (TAIII), as a steroid saponin in Anemarrhena asphodeloides, has favorable potential as an antitumor candidate. However, its hydrophobicity and low bioavailability severely limit its in vivo antitumor efficacy.

Methods

To overcome this drawback, TAIII-loaded liposomes (LP) were prepared to improve TAIII solubility and extend its circulation time. Furthermore, anti-CD44 antibody-modified LP (CD44-LP) was prepared to enhance the therapeutic index of TAIII. The LP and CD44-LP were also characterized through their biological activity, target selective binding and uptake, and in vivo pharmacokinetics.

Results

Compared with free TAIII, both LP and CD44-LP possessed a desirable sustained-release profile in vitro, with ~14.2- and 10.7-fold longer TAIII half-life, respectively, and 1.7- and 1.9-fold larger area under the curve, respectively. LP and CD44-LP enhanced TAIII antitumor activity against HepG2 cells and in a xenograft mouse model without detectable toxicity. In particular, CD44-LP exhibited notably higher cytotoxicity than did LP, with a lower half-maximal inhibitory concentration (48 h). CD44-LP exhibited stronger tumor inhibition, and the tumor inhibitory effect was 1.3-fold that of LP. Furthermore, confocal laser scanning microscopy and in vivo near-infrared imaging of a xenograft mouse model revealed that compared with LP, CD44-LP could effectively enhance tumor accumulation.

Conclusion

Taken together, the results indicate that both CD44-LP and LP can considerably extend TAIII circulation time, increase tumor-targeted accumulation, and enhance antitumor activity. Thus, the anti-CD44 antibody-modified liposome is a promising candidate for treating CD44-positive cancer with considerable antitumor effects.

In vitro and in vivo evaluation of cyclodextrin-based nanosponges for enhancing oral bioavailability of atorvastatin calcium

The aim of this study was to explore the feasibility of complexing the poorly water-soluble drug atorvastatin calcium (AC) with β-cyclodextrin (β-CD) based nanosponges (NS), which offer advantages of improving dissolution rate and eventually oral bioavailability. Blank NS were fabricated at first by reacting β-CD with the cross-linker carbonyldiimidazole at different molar ratios (1:2, 1:4, and 1:8), then NS of highest solubilization extent for AC were complexed with AC. AC loaded NS (AC-NS) were characterized for various physicochemical properties. Pharmacokinetic, pharmacodynamics and histological finding of AC-NS were performed in rats. The prepared AC-NS showed particles size ranged from 408.7 ± 12.9 to 423 ± 15.9 nm while zeta potential values varied from -21.7 ± 0.90 to -22.7 ± 0.85 mV. The loading capacity varied from 17.9 ± 1.21 to 34.1 ± 1.16%. DSC, FT-IR, and PXRD studies confirmed the complexation of AC with NS and amorphous state of the drug in the complex. AC-NS displayed a biphasic release pattern with increase in the dissolution rate of AC as compared to plain AC. Oral administration of AC-NS (1:4 w/w, drug: NS) to rats led to 2.13-folds increase in the bioavailability as compared to AC suspension. Pharmacodynamics studies in rats with fatty liver revealed significant reduction (p < .05) in total cholesterol, triglyceride, LDL-C and increased level of beneficial HDL-C along with improvement in the associated liver steatosis as confirmed through photomicrographs of liver sections. In this study, we confirmed that complexation of AC with NS would be a viable approach for improving oral bioavailability and in vivo performance of AC.

Atorvastatin-loaded nanostructured lipid carriers (NLCs): strategy to overcome oral delivery drawbacks

Atorvastatin (AT) is a widely used lipid-regulating drug to reduce cholesterol and triglycerides. Its poor aqueous solubility and hepatic metabolism require development of drug delivery systems able to improve its solubility and bypass hepatic effect. For this purpose, atorvastatin nanostructured lipid carriers (AT-NLCs) were prepared and characterized. AT-NLCs were prepared by emulsification using high-speed homogenization followed by ultrasonication. The prepared NLCs showed particle size between 162.5 ± 12 and 865.55 ± 28 nm while zeta potential values varied between −34 ± 0.29 and −23 ± 0.36 mV. They also showed high encapsulation efficiency (>87%) and amorphous state of the drug in lipid matrix. Pharmacokinetic parameters of optimized formulation (NLC-1; composed of 2% Gelucire^® 43/01, 8% Capryol^® PGMC, 2% Pluronic^®F68 and 0.5% lecithin) revealed 3.6- and 2.1-fold increase in bioavailability as compared to atorvastatin suspension and commercial product (Lipitor^®), respectively. Administration of NLC-1 led to significant reduction (p < .05) in the rats’ serum levels of total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL) and significant increase in high-density lipoprotein (HDL). This improvement was confirmed histologically by minimizing the associated hepatic steatosis. These investigations demonstrated the superiority of NLCs for improvement of oral bioavailability and in vivo performance of AT.

αvβ3 integrin receptor specific peptide modified, salvianolic acid B and panax notoginsenoside loaded nanomedicine for the combination therapy of acute myocardial ischemia

PURPOSE

To achieve the combination therapy of acute myocardial ischemia, arginyl-glycyl-aspartic acid (RGD) conjugated lipid was synthesized and RGD modified, salvianolic acid B (Sal B) and panax notoginsenoside (PNS) co-loaded lipid-polymer hybrid nanoparticles (RGD-S/P-LPNs) was fabricated an evaluated.

METHODS

RGD was conjugated to distearoyl phosphatidylethanolamine-polyethylene glycol (DSPE-PEG-NH₂) through amide linkage. Lipid-polymer hybrid nanoparticles (LPNs) were fabricated by nanoprecipitation method. RGD-S/P-LPNs was characterized in terms of morphology, size, charge, drug loading, entrapment, stability, drug release and cytotoxicity in vitro. Cardiac distribution, pharmacokinetics study and infarct therapy effect were evaluated in vivo.

RESULTS

The LPNs are generally spherical in shape with uniform size distribution, have sizes of 100-200nm and zeta potentials range from -30.7∼ -39.8. In vitro release behaviors of drugs loaded LPNs are in a sustained release manner, which does not exhibit obviously cytotoxicity against H9c2 cardiomyocytes. RGD-S/P-LPNs group shows the most significant cardiac distribution and infarct therapy effect in vivo.

CONCLUSION

The results illustrated that RGD modified dual drugs co-loaded LPNs are stable, sustained release carriers. Cardiac distribution, pharmacokinetics, and infarct therapy effect results suggested that the RGD-S/P-LPNs could improve the in vivo therapeutic efficacy of the double drugs.

Enhancement of Bioavailability and Pharmacodynamic Effects of Thymoquinone Via Nanostructured Lipid Carrier (NLC) Formulation

Thymoquinone (TQ), obtained from black cumin (Nigella sativa), is a natural product with anti-oxidant, anti-inflammatory, and hepatoprotective effects but unfortunately with poor bioavailability. Aiming to improve its poor oral bioavailability, TQ-loaded nanostructured lipid carriers (NLCs) were prepared by high-speed homogenization followed by ultrasonication and evaluated in vitro. Bioavailability and pharmacodynamic studies were also performed. The resultant NLCs showed poor physical homogeneity in Compritol 888 ATO Pluronic F127 system which consequently produced larger particle size and polydispersity index, smaller zeta potential values, and lower short-term (30 days) physical stability than other systems. Encapsulation efficiency percentage (EE%) lied between 84.6 ± 5% and 96.2 ± 1.6%. TQ AUC0-t values were higher in animals treated with NLCs, with a relative bioavailability of 2.03- and 3.97-fold (for F9 and F12, respectively) higher than TQ suspension, indicating bioavailability enhancement by NLC formulation. Hepatoprotective effects of F12 showed significant (P < 0.05) decrease in both serum alanine amino transferase and aspartate amino transferase to reach 305.0 ± 24.88 and 304.7 ± 23.55 U/ml, respectively, when compared with untreated toxic group. Anti-oxidant efficacy of F12 showed significant (P < 0.05) decline of malondialdehyde and elevation of reduced glutatione. This improvement was also confirmed histopathologically.

Carvedilol nano lipid carriers: formulation, characterization and in-vivo evaluation

The purpose of this study was to develop Carvedilol nanostructured lipid carriers (CAR-NLCs) using stearic acid and oleic acid as lipid, and to estimate the potential as oral delivery system for poorly water soluble drug. The particle-size analysis revealed that all the developed formulations were within the nanometer range. The EE and loading were found to be between 69.45-88.56% and 9.58-12.56%, respectively. The CAR-NLCopt showed spherical morphology with smooth surface under transmission electron microscope (TEM). The crystallization of the drug in NLC was investigated by powder X-ray diffraction and differential scanning calorimetry (DSC) and revealed that the drug was in an amorphous state in the NLC matrix. The ex vivo gut permeation study showed many folds increment in the permeation of CAR-NLCs compared to Carvedilol suspension (CAR-S). The oral bioavailability study of CAR was carried out using Wistar rats and relative bioavailability of CAR-NLCopt was found to be 3.95 fold increased in comparison with CAR-S. In vivo antihypertensive study in Wistar rats showed significant reduction in mean systolic BP by CAR-NLCopt vis-à-vis CAR-S (p < 0.05) owing to the drug absorption through lymphatic pathways. In conclusion, the NLC formulation remarkably improved the oral bioavailability of CAR and demonstrated a promising perspective for oral delivery of poorly water-soluble drugs. The promising findings in this investigation suggest the practicability of these systems for the enhancement of bioavailability of CAR.

Small molecule therapeutic-loaded liposomes as therapeutic carriers: from development to clinical applications

In this review, various methods and mechanisms for encapsulation of small therapeutic molecules in liposomes for targeted delivery and triggered release, as well as their potential in the clinical uses, are discussed.

Co-delivery of doxorubicin and the traditional Chinese medicine quercetin using biotin–PEG2000–DSPE modified liposomes for the treatment of multidrug resistant breast cancer

At present, multidrug resistance (MDR) in cancer therapy is an international problem, which is caused mostly by the overexpressed P-glycoprotein (P-gp) efflux pump.

Silymarin loaded liposomes for hepatic targeting: in vitro evaluation and HepG2 drug uptake

Silymarin has hepatoprotective properties and is used in treatment of various liver diseases, but its bioavailability from oral products is very poor. In order to overcome its poor oral bioavailability we have prepared silymarin loaded hepatic targeting liposomes suitable for parenteral administration. The liposomal formulations were composed of hydrogenated soy phosphatidylcholine and cholesterol with or without distearoylphosphoethanolamine-(polyethyleneglycol)-2000 and various amounts of β-sitosterol β-D-glucoside (Sito-G) as the hepatic targeting moiety. Increasing the amount of Sito-G in the liposomes gradually decreased drug encapsulation efficiencies from ∼70% to ∼60%; still showing promising drug encapsulation efficiencies. Addition of Sito-G to non-PEGylated liposomes clearly affected their drug release profiles and plasma protein interactions, whereas no effect on these was seen for the PEGylated liposomes. Non-PEGylated liposomes with 0.17 M ratio of Sito-G exhibited the highest cellular drug uptake of 37.5% for all of the studied liposome formulations. The highest cellular drug uptake in the case of PEGylated liposomes was 18%, which was achieved with 0.17 and 0.33 M ratio of added Sito-G. The liposome formulations with the highest drug delivery efficacy in this study showed hemolytic activities around 12.7% and were stable for at least 2 months upon storage in 20 mM HEPES buffer (pH 7.4) containing 1.5% Polysorbate 80 at 4 °C and room temperature. These results suggest that the Sito-G containing liposomes prepared in this work have hepatic targeting capability and that they are promising candidates for delivering silymarin to the liver.

[Nanotechnology: a big revolution from the small world]

Nanotechnology is a multidisciplinary field originating from the interaction of several different disciplines, such as engineering, physics, biology and chemistry. New materials and devices effectively interact with the body at molecular level, yielding a brand new range of highly selective and targeted applications designed to maximize the therapeutic efficiency while reducing the side effects. Liposomes, quantum dots, carbon nanotubes and superparamagnetic nanoparticles are among the most assessed nanotechnologies. Meanwhile, other futuristic platforms are paving the way toward a new scientific paradigm, able to deeply change the research path in the medical science. The growth of nanotechnology, driven by the dramatic advances in science and technology, clearly creates new opportunities for the development of the medical science and disease treatment in human health care. Despite the concerns and the on-going studies about their safety, nanotechnology clearly emerges as holding the promise of delivering one of the greatest breakthroughs in the history of medical science.

Improved pharmacokinetics and reduced toxicity of brucine after encapsulation into stealth liposomes: role of phosphatidylcholine

OBJECTIVE

Brucine was encapsulated into stealth liposomes using the ammonium sulfate gradient method to improve therapeutic index.

MATERIALS AND METHODS

Four brucine stealth liposomal formulations were prepared, which were made from different phosphatidylcholines (PCs) with different phase transition temperatures (T(m)). The PCs used were soy phosphatidylcholine (SPC), dipalmitoyl phosphatidylcholine (DPPC), hydrogenated soy phosphatidylcholine (HSPC), and distearoyl phosphatidylcholine (DSPC). The stabilities, pharmacokinetics, and toxicities of these liposomal formulations were evaluated and compared.

RESULTS

Size, zeta potential, and entrapment efficiency of brucine-loaded stealth liposomes (BSL) were not influenced by PC composition. In vitro release studies revealed that drug release rate increased with decreased T(m) of PCs, especially with the presence of rat plasma. After intravenous administration, the area under the curve (AUC) values of BSL-SPC, BSL-DPPC, BSL-HSPC, and BSL-DSPC in plasma were 7.71, 9.24, 53.83, and 56.83-fold as large as that of free brucine, respectively. The LD(50) values of brucine solution, BSL-SPC, BSL-DPPC, BSL-HSPC, and BSL-DSPC following intravenous injection were 13.17, 37.30, 37.69, 51.18, and 52.86 mg/kg, respectively. It was found in calcein retention experiments that the order of calcein retention in rat plasma was SPC < DPPC << HSPC < DSPC stealth liposomes.

CONCLUSION

PC composition could exert significant influence on the stabilities, pharmacokinetics, and toxicities of brucine-loaded stealth liposomes. DSPC or HSPC with T(m) above 50°C should be used to prepare the stealth liposomal formulation for the intravenous delivery of brucine. However, it was found in the present paper that the pharmacokinetics and toxicity of BSL were not influenced by the PC composition when the T(m) of the PC was in the range of -20°C to 41°C.