Plasma kinetics of an LDL-like nanoemulsion and lipid transfer to HDL in subjects with glucose intolerance

Enhanced proton treatment with a LDLR-ligand peptide-conjugated gold nanoparticles targeting the tumor microenvironment in an infiltrative brain tumor model

The tumor microenvironment (TME) of glioblastoma malforms (GBMs) contains tumor invasiveness factors, microvascular proliferation, migratory cancer stem cells and infiltrative tumor cells, which leads to tumor recurrence in the absence of effective drug delivery in a Blood Brain Barrier (BBB)-intact TME and radiological invisibility. Low-density lipoprotein receptor (LDLR) is abundant in the blood brain barrier and overexpressed in malignant glioma cells. This study aimed to treat the TME with transmitted proton sensitization of LDLR ligand-functionalized gold nanoparticles (ApoB@AuNPs) in an infiltrative F98 glioma rat model. BBB-crossing ApoB@AuNPs were selectively taken up in microvascular endothelial cells proliferation and pericyte invasion, which are therapeutic targets in the glioma TME. Proton sensitization treated the TME and bulk tumor volume with enhanced therapeutic efficacy by 67-75% compared to that with protons alone. Immunohistochemistry demonstrated efficient treatment of endothelial cell proliferation and migratory tumor cells of invasive microvessels in the TME with saving normal tissues. Taken together, these data indicate that the use of LDLR ligand-functionalized gold nanoparticles is a promising strategy to treat infiltrative malignant glioma while overcoming BBB crossing.

Nanoemulsion delivery systems for enhanced efficacy of antimicrobials and essential oils

The ever-growing threat of new and existing infectious diseases in combination with antimicrobial resistance requires the need for innovative and effective forms of drug delivery. Optimal drug delivery systems for existing and newly developed antimicrobials can enhance drug bioavailability, enable site-specific drug targeting, and overcome current limitations of drug formulations such as short elimination half-lives, poor drug solubility, and undesirable side effects. Nanoemulsions (NE) consist of nanometer-sized droplets stabilized by emulsifiers and are typically more stable and permeable due to their smaller particle sizes and higher surface area compared to conventional emulsions. NE have been identified as a promising means of antimicrobial delivery due to their intrinsic antimicrobial properties, ability to increase drug solubility, stability, bioavailability, organ and cellular targeting potentials, capability of targeting biofilms, and potential to overcome antimicrobial resistance. Herein, we discuss non-drug loaded essential oil-based NE that can confer antimicrobial actions through predominantly physical or biochemical mechanisms without drug payloads. We also describe drug-loaded NE for enhanced antimicrobial efficacy by augmenting the potency of existing antimicrobials. We highlight the versatility of NE to be administered through multiple different routes (oral, parenteral, dermal, transdermal, pulmonary, nasal, ocular, and rectal). We summarize recent advances in the clinical translation of antimicrobial NE and shed light on future development of effective antimicrobial therapy to combat infectious diseases.

Nanoemulsions: A Better Approach for Antidiabetic Drug Delivery

Conventional delivery of antidiabetic drugs faces many problems like poor absorption, low bioavailability, and drug degradation. Nanoemulsion is a unique drug technology, which is very suitable for the delivery of antidiabetic drugs. In recent years, the flaws of delivering anti-hypoglycaemic drugs have been overcome by choosing nanoemulsion drug technology. They are thermodynamically stable and also provide the therapeutic agent for a longer duration. Generally, nanoemulsions are made up of either oil-in-water or water-in-oil and the size of the droplets is from fifty to thousand nanometer. Surfactants are critical substances that are added in the manufacturing of nanoemulsions. Only the surfactants which are approved for human use can be utilized in the manufacturing of nanoemulsions. Generally, the preparation of emulsions includes mixing of the aqueous phase and organic phase and using surfactant with proper agitation. Nanoemulsions are used for antimicrobial drugs, and they are also used in the prophylaxis of cancer. Reduction in the droplet size may cause variation in the elastic and optical behaviour of nanoemulsions.

Nanomaterials for the theranostics of obesity

As a chronic and lifelong disease, obesity not only significant impairs health but also dramatically shortens life span (at least 10 years). Obesity requires a life-long effort for the successful treatment because a number of abnormalities would appear in the development of obesity. Nanomaterials possess large specific surface area, strong absorptivity, and high bioavailability, especially the good targeting properties and adjustable release rate, which would benefit the diagnosis and treatment of obesity and obesity-related metabolic diseases. Herein, we discussed the therapy and diagnosis of obesity and obesity-related metabolic diseases by using nanomaterials. Therapies of obesity with nanomaterials include improving intestinal health and reducing energy intake, targeting and treating functional cell abnormalities, regulating redox homeostasis, and removing free lipoprotein in blood. Diagnosis of obesity-related metabolic diseases would benefit the therapy of these diseases. The development of nanomaterials will promote the diagnosis and therapy of obesity and obesity-related metabolic diseases.

Organic effects of associating paclitaxel with a lipid-based nanoparticle system on a nonhuman primate, Cebus apella

Lipid-based nanoparticle systems have been used as vehicles for chemotherapeutic agents in experimental cancer treatments. Those systems have generally been credited with attenuating the severe toxicity of chemotherapeutic agents. This study aimed to investigate the effects of associating paclitaxel (PTX) with a lipid-based nanoparticle system on a nonhuman primate, Cebus apella, documenting the toxicity as measured by serum biochemistry, which is a detailed analysis of blood and tissue. Eighteen C. apella were studied: three animals were treated with cholesterol-rich nanoemulsion (LDE) only, without PTX, administered intravenously every 3 weeks, during six treatment cycles; six animals were treated with PTX associated with LDE at the same administration scheme, three with lower (175 mg/m²) and three with higher (250 mg/m²) PTX doses; and six animals were treated with commercial PTX, three with the lower and three with the higher doses. In the LDE-PTX group, no clinical toxicity appeared, and the weight-food consumption curve was similar to that of the controls. Two animals treated with commercial PTX presented weight loss, nausea and vomiting, diarrhea, skin flaking, 70% loss of body hair, and decreased physical activity. The use of LDE as a carrier at both lower and higher doses reduced the toxicity of the drug in this species, which is closely related to human subjects. This was observed not only by clinical, biochemical, and hematological profiles but also by the histopathological analysis. The results of this study support the assumption that lipid-based nanoparticle systems used as drug carriers can serve as valuable tools to decrease the toxicity and increase the safety of chemotherapeutic agents.

Receptor-Mediated Drug Delivery Systems Targeting to Glioma

Glioma has been considered to be the most frequent primary tumor within the central nervous system (CNS). The complexity of glioma, especially the existence of the blood-brain barrier (BBB), makes the survival and prognosis of glioma remain poor even after a standard treatment based on surgery, radiotherapy, and chemotherapy. This provides a rationale for the development of some novel therapeutic strategies. Among them, receptor-mediated drug delivery is a specific pattern taking advantage of differential expression of receptors between tumors and normal tissues. The strategy can actively transport drugs, such as small molecular drugs, gene medicines, and therapeutic proteins to glioma while minimizing adverse reactions. This review will summarize recent progress on receptor-mediated drug delivery systems targeting to glioma, and conclude the challenges and prospects of receptor-mediated glioma-targeted therapy for future applications.

Transfer of lipids to high-density lipoprotein (HDL) is altered in patients with familial hypercholesterolemia

OBJECTIVE

In familial hypercholesterolemia (FH), the metabolism and anti-atherogenic functions of HDL can be affected by the continuous interactions with excess LDL amounts. Here, lipid transfers to HDL, an important step for HDL intravascular metabolism and for HDL role in reverse cholesterol transport (RCT) were investigated in FH patients.

METHODS

Seventy-one FH patients (39 ± 15 years, LDL-cholesterol=274 ± 101; HDL-cholesterol=50 ± 14 mg/dl) and 66 normolipidemic subjects (NL) (38 ± 11 years, LDL-cholesterol=105 ± 27; HDL-cholesterol=52 ± 12 mg/dl) were studied. In vitro, lipid transfers were evaluated by incubation of plasma samples (37°C, 1h) with a donor lipid nanoemulsion labeled with 3H-triglycerides (TG) and 14C-unesterified cholesterol (UC) or with 3H-cholesteryl ester (EC) and 14C-phospholipids (PL). Radioactivity was counted at the HDL fraction after chemical precipitation of apolipoprotein (apo) B-containing lipoproteins and the nanoemulsion. Data are % of total radioactivity measured in the HDL fraction.

RESULTS

Transfer of UC to HDL was lower in FH than in NL (5.6 ± 2.1 vs 6.7 ± 2.0%, p=0.0005) whereas TG (5.5 ± 3.1 vs 3.7 ± 0.9%, p=0.018) and PL (20.9 ± 4.6 vs 18.2 ± 3.7 %, p=0.023) transfers were higher in FH. EC transfer was equal. By multivariate analysis, transfers of all four lipids correlated with HDL-cholesterol and with apo A-I.

CONCLUSION

FH elicited marked changes in three of the four tested lipid transfers to HDL. The entry of UC into HDL for subsequent esterification is an important driving force for RCT and reduction of UC transfer to HDL was previously associated to precocious coronary heart disease. Therefore, in FH, HDL functions can be lessened, which can also contribute to atherogenesis.