Research on the fate of polymeric nanoparticles in the process of the intestinal absorption based on model nanoparticles with various characteristics: size, surface charge and pro-hydrophobics.

BACKGROUND: The use of drug nanocarriers to encapsulate drugs for oral administration may become an important strategy in addressing the challenging oral absorption of some drugs. In this study-with the premise of controlling single variables-we prepared model nanoparticles with different particle sizes, surface charges, and surface hydrophobicity/hydrophilicity. The two key stages of intestinal nanoparticles (NPs) absorption-the intestinal mucus layer penetration stage and the trans-intestinal epithelial cell stage-were decoupled and analyzed. The intestinal absorption of each group of model NPs was then investigated. RESULTS: Differences in the behavioral trends of NPs in each stage of intestinal absorption were found to result from differences in particle properties. Small size, low-magnitude negative charge, and moderate hydrophilicity helped NPs pass through the small intestinal mucus layer more easily. Once through the mucus layer, an appropriate size, positive surface charge, and hydrophobic properties helped NPs complete the process of transintestinal epithelial cell transport. CONCLUSIONS: To achieve high drug bioavailability, the basic properties of the delivery system must be suitable for overcoming the physiological barrier of the gastrointestinal tract.

Intradiscal Methylene Blue Injection for Discogenic Low Back Pain: A Meta-Analysis.

OBJECTIVES: The purpose of this study was to assess the effects of intradiscal methylene blue (MB) injection on discogenic low back pain (DLBP). METHODS: We conducted an electronic search of the PubMed, Ovid, Ovid MEDLINE and Embase databases using the search terms "low back pain" and "methylene blue"; the search was limited to English language articles from database inception to October 2017. In addition, the reference lists of all included studies were manually searched. Two reviewers independently assessed the quality of the studies, extracted data from the included studies, and analyzed the data. RESULTS: Five studies were included. The results of the meta-analysis indicated that the effects of intradiscal MB injection between preoperation and postoperation on DLBP were statistically significant based on the 3-month visual analog scale (VAS) or numeric rating scale (NRS) (weighted mean difference [WMD] = 3.61; 95% confidence interval [CI]: 2.46 to 4.76; P < 0.05) and Oswestry Disability Index (ODI) (WMD = 24.64, 95% CI: 12.07 to 37.21, P < 0.05), the 6-month VAS or NRS (WMD = 2.95; 95% CI: 1.20 to 4.71; P < 0.05) and ODI (WMD = 23.21, 95% CI: 12.89 to 33.53, P < 0.05), and the 12-month VAS or NRS (WMD = 3.19; 95% CI: 0.99 to 5.40; P < 0.05) and ODI (standard mean difference = 29.51, 95% CI: 20.60 to 38.42, P < 0.05). CONCLUSIONS: Intradiscal MB injection can reduce pain severity and improve the ODI score in individuals with discogenic low back pain. Although intradiscal MB injection seems to be a safe and effective treatment for discogenic low back pain, the clinical benefits for patients with discogenic low back pain need to be further appraised in larger samples and more in-depth studies.

Mucus- and pH-mediated controlled release of core-shell chitosan nanoparticles in the gastrointestinal tract for diabetes treatment.

For the successful oral delivery of peptide drugs, considerable barriers created by the harsh environment of the gastrointestinal tract, mucus, and epithelial cells must be overcome. This study was to establish a core-shell structure with chitosan (CS) nanoparticles (NP) as the core and poly-N-(2-hydroxypropyl) methacrylamide (pHPMA) as the intelligent escape shell to overcome pH and mucus barriers and improve the delivery efficiency of peptide drugs. A core-shell system (COS) composed of pHPMA-AT-1002-cys-chitosan (LRA-PA-CNPs) was prepared and used for the treatment of type 2 diabetes mellitus with the large-molecule peptide drug liraglutide (LRA). The complete COS system was observed through electron microscopy; the particle size of the LRA-PA-CNPs was approximately 160 nm; the encapsulation efficiency was approximately 69% ± 5%; the zeta potential was close to neutral; the mucus and epithelial penetration of the COS system were increased; and animal experiments showed that the COS system enhanced the oral hypoglycaemic effect of LRA.HIGHLIGHTSIntelligent escape material of poly-N-(2-hydroxypropyl) methacrylamide as the shell.Core-shell nanoparticles penetrate the mucus layer and exposing the chitosan core.Overcome pH and mucus barriers to improve the delivery efficiency of peptide drugs.

Construction and Evaluation of Liraglutide Delivery System based on Milk Exosomes: A New Idea for Oral Peptide Delivery.

BACKGROUND: Increasing the bioavailability of peptide or protein drugs have always been an important topic in the field of pharmacy. Milk exosomes as a carrier for oral drug delivery systems have begun to attract attention in recent years. The application of oral milk exosomes carriers to peptide drugs, such as liraglutide, is worth trying. OBJECTIVES: Milk-derived exosomes are used in this study to try to encapsulate the GLP-1 receptor agonist liraglutide and the feasibility of using this drug delivery system for oral biomolecules delivery in the future is explored. METHODS: The size and morphology of milk exosomes were characterized. The gastrointestinal stability of milk exosomes was evaluated in a dialysis bag. The cellular uptake of milk exosomes in the intestinal cells was observed. Six drug loading methods have been evaluated and compared preliminarily and they are incubation method, sonication method, extrusion method, freeze-thaw cycles method, saponin-assisted method and electroporation method. RESULTS: As demonstrated in this study, milk exosomes showed significant stability in the gastrointestinal environment and excellent affinity with intestinal cells, indicating their unique benefits used for drug oral delivery. Effective drug loading method for exosomes is challenging. Among the six drug loading methods used in this study, the liraglutide-Exo prepared by the extrusion method obtained the largest drug load, which was 2.45 times the direct incubation method. The liraglutide-Exo obtained by the freeze-thaw cycles method has the smallest morphological change. CONCLUSION: The study showed that milk exosome-based oral drug delivery systems are promising.

Orally administered intelligent self-ablating nanoparticles: a new approach to improve drug cellular uptake and intestinal absorption.

Oral drug delivery to treat diabetes is being increasingly researched. The mucus and the epithelial cell layers hinder drug delivery. We designed a self-ablating nanoparticle to achieve smart oral delivery to overcome the gastrointestinal barrier. We used the zwitterionic dilauroyl phosphatidylcholine, which exhibits a high affinity toward Oligopeptide transporter 1, to modify poly(lactic-co-glycolic acid) nanoparticles and load hemagglutinin-2 peptide to facilitate its escape from lysosomes. Nanoparticles exhibit a core-shell structure, the lipid layer is degraded by the lysosomes when the nanoparticles are captured by lysosomes, then the inner core of the nanoparticles gets exposed. The results revealed that the self-ablating nanoparticles exhibited higher encapsulation ability than the self-assembled nanoparticles (77% vs 64%) and with better stability. Quantitative cellular uptake, cellular uptake mechanisms, and trans-monolayer cellular were studied, and the results revealed that the cellular uptake achieved using the self-ablating nanoparticles was higher than self-assembling nanoparticles, and the number of uptake pathways via which the self-ablating nanoparticles functioned were higher than the self-assembling nanoparticles. Intestinal mucus permeation, in vivo intestinal circulation, was studied, and the results revealed that the small self-assembling nanoparticles exhibit a good extent of intestinal uptake in the presence of mucus. In vitro flip-flop, intestinal circulation revealed that the uptake of the self-ablating nanoparticles was 1.20 times higher than the self-assembled nanoparticles. Pharmacokinetic study and the pharmacodynamic study showed that the bioavailability and hypoglycemic effect of self-ablating nanoparticles were better than self-assembled nanoparticles.

Relationship and improvement strategies between drug nanocarrier characteristics and hemocompatibility: What can we learn from the literature.

This article discusses the various blood interactions that may occur with various types of nano drug-loading systems. Nanoparticles enter the blood circulation as foreign objects. On the one hand, they may cause a series of inflammatory reactions and immune reactions, resulting in the rapid elimination of immune cells and the reticuloendothelial system, affecting their durability in the blood circulation. On the other hand, the premise of the drug-carrying system to play a therapeutic role depends on whether they cause coagulation and platelet activation, the absence of hemolysis and the elimination of immune cells. For different forms of nano drug-carrying systems, we can find the characteristics, elements and coping strategies of adverse blood reactions that we can find in previous researches. These adverse reactions may include destruction of blood cells, abnormal coagulation system, abnormal effects of plasma proteins, abnormal blood cell behavior, adverse immune and inflammatory reactions, and excessive vascular stimulation. In order to provide help for future research and formulation work on the blood compatibility of nano drug carriers.

A Anchoring Technique Using Long Bent Rods for Open Reduction of Thoracolumbar Dislocation.

OBJECTIVE: The purpose of this study was to evaluate the effectiveness of a novel surgical open reduction method for thoracolumbar dislocation. MATERIALS AND METHODS: This study included a total of 15 patients of thoracolumbar dislocation. All patients underwent posterior thoracolumbar open reduction and fixation using this technique. Preoperative x-ray, computed tomography (CT), and magnetic resonance imaging were used to evaluate the dislocation. The American Spinal Injury Association grade of spinal cord injury before and afer the operation were record. All patients were followed up for 2 years, and x-ray, CT were used to observe postoperative reduction and fusion. RESULTS: Postoperative x-ray and CT images of all patients indicated good recovery of the spinal sequence, and no neurological deterioration or surgically related complications occurred. All patients were followed up for 2 years, no patients were lost to follow-up. During the follow-up period, x-ray and CT images showed no complications related to internal fixation such as fracture and loosening of screws and rods were found. CONCLUSION: A anchoring technique using long bent rods is a safe, simple, accurate, and easy to replicate and implement method, which can be applied in the surgical treatment for thoracolumbar dislocation.