ABSTRACT
An effective palladium nanocatalyst (Fe3O4@SiO2-FPBA-DTPA-Pd) was proposed and prepared, which was immobilized on magnetic silica with ethylenediamine pentaacetic acid and formylphenylboronic acid as biligands. A series of characterizations showed that Fe3O4@SiO2-FPBA-DTPA-Pd was 5-15 nm and contained 1.44 mmol/g Pd2+/Pd0. It was stable below 232.7 °C, and its saturation magnetization value was 21.17 emu/g which was easily recycled by a magnet. Its catalytic ability was evaluated through 7 Suzuki reactions and 15 Heck reactions. Results showed that the yields of 14 reactions catalyzed by Fe3O4@SiO2-FPBA-DTPA-Pd were more than 90%, while were better than those of the other two immobilized Pd catalysts on a single diethyltriamine pentaacetic acid (DTPA) group or boronic acid group. Moreover, Fe3O4@SiO2-FPBA-DTPA-Pd showed good reusability in both Suzuki and Heck reactions. In two model Suzuki and Heck reactions, after seven cycles, its yields were still above 95% without significant loss, which exceeded those of many reported catalysts; therefore, it has great potential in future large-scale industrial production.
ABSTRACT
A novel phenylboronic acid and amino bifunctional modified silica gel (SiO2-NH2-FPBA) was prepared, which was 30-80 µm, had a pore size of 8.69 nm, a specific surface area of 206.89 m2/g, was stable at low temperature, and contained 0.4793 mmol/g of the phenylboronic acid group and 1.6377 mmol/g of the amino group. It was used to develop a rapid separation method for phenolic acids. The results showed that it could adsorb 93.64 mg/g caffeic acid, 89.35 mg/g protocatechuic acid and 79.66 mg/g gallic acid. The adsorption process was consistent with the pseudo-second-order model (R2 > 0.99), and fitted the Langmuir isotherm model well (R2 > 0.99). CH3COOH could effectively desorb phenolic acids (>90%) and did not destroy their structures. When SiO2-NH2-FPBA was added to crude extract of Clerodendranthus spicatus, 93.24% of the phenolic acids could be captured, and twenty-two kinds of phenolic acids were identified by Q Exactive HF LC-MS. Furthermore, the isolated phenolic acids from Clerodendranthus spicatus possessed great DPPH, ABTS, and hydroxyl radicals scavenging activities and ferric reducing power. They also demonstrated effective inhibition of α-amylase and α-glucosidase activities (IC50 = 110.63 ± 3.67 µg/mL and 64.76 ± 0.30 µg/mL, respectively). The findings indicate that SiO2-NH2-FPBA has significant potential in practical applications of separating active constituents from natural resources.
Subject(s)
Antioxidants , Lamiaceae , Antioxidants/pharmacology , Antioxidants/chemistry , Hypoglycemic Agents/pharmacology , Hypoglycemic Agents/chemistry , Silicon Dioxide , Lamiaceae/chemistry , Plant Extracts/pharmacology , Plant Extracts/chemistryABSTRACT
The dimension of the void area in pavement is crucial to its structural safety. However, there is no effective method to measure its geometric parameters. To address this issue, a void size extraction algorithm based on the continuous wavelet transform (CWT) method was proposed using ground-penetrating radar (GPR) signal. Firstly, the finite-difference time-domain (FDTD) method was used to investigate the GPR response of void areas with different shapes, sizes, and depths. Next, the GPR signal was processed using the CWT method, and a 3D image based on the CWT result was used to visualize the void area. Based on the differences between the void and normal pavement in the time and frequency domains, the signal with maximum energy from the CWT time-frequency result was extracted and combined to reconstruct the new B-scan image, where void areas have energy concentration phenomenon. Based on this, width and depth of void detection algorithm was proposed to recognize the void area. Finally, the detection algorithm was verified both in numerical model and physical lab model. The results indicated that the CWT time-frequency energy spectrum can be used to enhance the void feature, and the 3D CWT image can clearly visualize the void area with a highlighted energy area. After fully testing and validating in numerical and lab models, our proposed method achieved high accuracy in void width and depth detection, providing a precise method for estimating void dimension in pavement. This method can guide DOT departments to carry out pre-maintenance, thereby ensuring pavement safety.
ABSTRACT
A water-soluble negative sulfonic propyl ether ß-CD polymer (SPE-ß-CDP) to be used as chiral selector in capillary electrophoresis (CE) was polymerized. The sulfonic substitution degree of each ß-CD in SPE-ß-CDP was statistically homogenized. The only one negative peak in electrophoretogram with indirect ultraviolate method proved its uniformity of electrophoretic behavior. There were 7.12 sulfonic substitution in ß-CD unit and 164 µmole ß-CD units in each gram of SPE-ß-CDP, which corresponded a molecular weight of 7000 or more. Compared with monomer, SPE-ß-CDP was lower effect on electrical current of CE, indicating a high concentration of SPE-ß-CDP could be added. Its separation ability was verified by 12 chiral drugs. SPE-ß-CDP also showed advantages of good water solubility, easy preparation and recovery to reduce the overall cost. However, five of 12 chiral drugs were hardly to be fully separated which was normal for any kind of chiral selector. A newly adjustable gravity mediated capillary electrophoresis (AGM-CE) technology was proposed and combined with SPE-ß-CDP to enhance the chiral separation efficiencies of propranolol, salbutamol, omeprazole, ofloxacin and phenoxybenzamine which were markedly improved to 3.02, 1.17, 7.63, 4.14, and 2.81, respectively. Furthermore, its gradient mode (AGMg-CE) was also used to improve resolution through utilizing the zero mobility point, at which the effective apparent mobility of one racemate was zero. Resolutions of five chiral drugs were significantly improved, especially resolution of carvedilol changed from 0.43 to 1.0. These indicated SPE-ß-CDP as chiral selector, AGM-CE and AGMg-CE as new CE technologies had a great potential in chiral separation.
Subject(s)
Electrophoresis, Capillary , Ethers , Stereoisomerism , Electrophoresis, Capillary/methods , Water , Hydrogen-Ion ConcentrationABSTRACT
Cr(vi) is a great threat to the ecological environment and human health, so it is urgent to remove Cr(vi) from the environment. In this study, a novel silica gel adsorbent SiO2-CHO-APBA containing phenylboronic acids and aldehyde groups was prepared, evaluated and applied for removing Cr(vi) from water and soil samples. The adsorption conditions including pH, adsorbent dosage, initial concentration of Cr(vi), temperature and time were optimized. Its ability in removing Cr(vi) was investigated and compared with three other common adsorbents, SiO2-NH2, SiO2-SH and SiO2-EDTA. Data showed SiO2-CHO-APBA had the highest adsorption capacity of 58.14 mg g-1 at pH 2 and could reach adsorption equilibrium in about 3 h. When 50 mg SiO2-CHO-APBA was added in 20 mL of 50 mg L-1 Cr(vi) solution, more than 97% of Cr(vi) was removed. A mechanism study revealed that a cooperative interaction of both the aldehyde and boronic acid groups is attributed to Cr(vi) removal. The reducing function was gradually weakened with the consumption of the aldehyde group, which was oxidized to a carboxyl group by Cr(vi). This SiO2-CHO-APBA adsorbent was successfully used for the removal of Cr(vi) from soil samples with satisfactory results which indicates a good potential in agriculture and other fields.
ABSTRACT
The oral absorption of exenatide, a type 2 diabetes medication, can be increased by employing lipid nanocapsules (LNC). To increase mucus permeability and exenatide intestinal absorption, reverse micelle lipid nanocapsules (RM-LNC) were prepared and their surface was modified with DSPE-PEG-FA. The RM-LNC with surface modification of DSPE-PEG-FA (FA-RM-LNC) were able to target enterocytes and reduce mucus aggregation in the intestine. Furthermore, in vitro absorption at different intestinal sites and flip-flop intestinal loop experiments revealed that LNCs with surface modification significantly increased their absorption efficiency in the small intestine. FA-RM-LNC delivers more drugs into Caco-2 cells via caveolin-, macrophagocytosis-, and lipid raft-mediated endocytosis. Additionally, the enhanced transport capacity of FA-RM-LNC was observed in a study of monolayer transport in Caco-2 cells. The oral administration of exenatide FA-RM-LNC resulted in a prolonged duration of hypoglycemia in diabetic mice and a relative bioavailability (BR) of up to 7.5% in rats. In conclusion, FA-RM-LNC can target enterocytes and has promising potential as a nanocarrier for the oral delivery of peptides.
Subject(s)
Diabetes Mellitus, Experimental , Diabetes Mellitus, Type 2 , Nanocapsules , Nanoparticle Drug Delivery System , Animals , Humans , Mice , Rats , Caco-2 Cells , Diabetes Mellitus, Experimental/drug therapy , Diabetes Mellitus, Type 2/drug therapy , Exenatide , Folic Acid , Intestines , Lipids , Micelles , PeptidesABSTRACT
Bacterial infection and oxidative stress hinder clinical wound healing. Therefore, wound dressings with antibacterial and antioxidative properties are urgently needed. In this study, a type of quaternized lignin (QL) functionalized poly(hexamethylene biguanide) hydrochloride (PHMB) complex incorporated polyacrylamide (QL-PHMB-PAM) hydrogel was developed as a multifunctional dressing material for the promotion of infected wound repair. Owing to the abundant catechol groups of quaternized lignin, the QL-PHMB-PAM hydrogel exhibited robust repeatable adhesiveness to various substrates with antioxidative properties. Additionally, the antibacterial components of PHMB in the QL-PHMB-PAM composite hydrogel showed high efficiency and long-term antibacterial activity against Staphylococcus aureus (S.aureus), Escherichia coli (E.coli), and methicillin-resistant S. aureus (MRSA; up to 100%). Furthermore, in vivo experiments indicated that this multifunctional hydrogel accelerated the healing of S. aureus-infected wounds by promoting the reconstruction of blood vessels and hair follicles. These results demonstrate that this antioxidative, antibacterial, and bioadhesive hydrogel is a promising alternative wound dressing material for the prevention of bacterial infections and the acceleration of infected wound regeneration.
Subject(s)
Methicillin-Resistant Staphylococcus aureus , Staphylococcal Infections , Humans , Antioxidants/pharmacology , Antioxidants/therapeutic use , Hydrogels , Staphylococcus aureus , Lignin , Staphylococcal Infections/drug therapy , Anti-Bacterial Agents/pharmacology , Bandages , Wound HealingABSTRACT
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.
Subject(s)
Chitosan , Diabetes Mellitus, Type 2 , Nanoparticles , Animals , Drug Carriers/chemistry , Chitosan/chemistry , Insulin , Diabetes Mellitus, Type 2/drug therapy , Delayed-Action Preparations , Administration, Oral , Nanoparticles/chemistry , Mucus , Gastrointestinal Tract , Hydrogen-Ion ConcentrationABSTRACT
Purpose: Effective therapy for rheumatoid arthritis (RA) keeps a challenge due to the complex pathogenesis of RA. It is not enough to completely inhibit the process of RA with any single therapy method. The purpose of the research is to compensate for the insufficiency of monotherapy using multiple treatment regimens with different mechanisms. Material and Methods: In this study, we developed a new method to synthesize mesoporous silica nanoparticles hybridized with photosensitizer PCPDTBT (HNs). Branched polyethyleneimine-folic acid (PEI-FA) could be coated on the surface of HNs through electrostatic interactions. It simultaneously blocked the hypoxia-activated prodrug tirapazamine loaded into the mesopores and binded with Mcl-1 siRNA (siMcl-1) that interfered with the expression of the anti-apoptotic protein Mcl-1. Released from the co-delivery nanoparticles (PFHNs/TM) Tirapazamine and siMcl-1 upon exposure to acidic conditions of endosomes/lysosomes in activated macrophages. Under NIR irradiation, photothermal therapy and photodynamic therapy derived from PCPDTBT, hypoxia-activated chemotherapy derived from tirapazamine, and RNAi derived from siMcl-1 were used for the combined treatment for RA by killing activated macrophages. PEI-FA-coated PFHNs/TM exhibited activated macrophage-targeting characteristics, thereby enhancing the in vitro and in vivo NIR-induced combined treatment of RA. Results: The prepared PFHNs/TM have high blood compatibility (far below 5% of hemolysis) and ideal in vitro phototherapy effect while controlling the TPZ release and binding siMcl-1. We prove that PEI-FA-coated PFHNs/TM not only protect the bound siRNA but also are selectively uptaked by activated macrophages through FA receptor-ligand-mediated endocytosis, and effectively silence the target anti-apoptotic protein by siMcl-1 transfection. In vivo, PFHNs/TM have also been revealed to be selectively enriched at the inflammatory site of RA, exhibiting NIR-induced anti-RA efficacy. Conclusion: Overall, these FA-functionalized, pH-responsive PFHNs/TM represent a promising platform for the co-delivery of chemical drugs and nucleic acids for the treatment of RA cooperating with NIR-induced phototherapy.
Subject(s)
Arthritis, Rheumatoid , Nanoparticles , Humans , Tirapazamine/pharmacology , RNA Interference , Nanoparticle Drug Delivery System , Myeloid Cell Leukemia Sequence 1 Protein , Phototherapy/methods , Arthritis, Rheumatoid/drug therapy , RNA, Small Interfering , Folic Acid , HypoxiaABSTRACT
In this study, while aiming at the prevention of fire accidents in underground commercial streets, an underground commercial street is selected as a research object, and the building fire is numerically simulated using the PyroSim software. Fire simulation scenarios are divided according to different fire zones by analyzing the temperature, carbon monoxide (CO) concentration, and visibility in the smoke layer inside a building. The available safe evacuation time is calculated according to the critical fire hazard judgment conditions. We found that the time when the flue gas temperature and CO concentration reached the critical value in the fire site was longer than the time when the visibility reached the critical value reducing or even avoiding the spread of smoke from the fire area to the evacuation stairs can provide effective help for crowd evacuation. Finally, the safety of the building is evaluated, and fire prevention countermeasures are defined based on the actual situation and fire numerical simulation results to reduce fire incidence, casualties, and economic losses.
Subject(s)
Carbon Monoxide , Fires , Accidents , Carbon Monoxide/analysis , Computer Simulation , Fires/prevention & control , Smoke/analysisABSTRACT
Biofilm formation on biomedical devices is a major cause of device-associated infection. Traditional antibiotic treatment for biofilm-associated infection increases the risk of multidrug resistance. Thus, there is an urgent need to develop antibiotic-free strategies to prevent biofilm formation on biomedical devices. Herein, we report a layer-by-layer strategy to construct an antifouling and bactericidal dual-functional coating for silicone rubber (SR)-based substrates. Five zwitterionic active ester copolymers, p(SBMA-co-NHSMA), with varied zwitterionic pSBMA components that ranged from 50 to 90% (molar ratio) were precisely prepared. Based on -NH2/NHS chemistry, a zwitterionic pSBMA antifouling coating was successfully constructed on an -NH2-activated SR surface, while a biguanide polymer (PHMB) bactericidal coating was consequently tethered. The relationship between the composition of the polymeric coating and the overall antibacterial property (antifouling and bactericidal) that was endowed to the SR surface was established. The in vitro and in vivo results consistently showed that the optimal p(SBMA-co-NHSMA) copolymer (SBMA/NHSMA with molar percentage of 70/30) synergistically utilized antifouling and bactericidal abilities to endow a highly efficient overall antibacterial property (near 100% antibacterial ratios) to SR70-PHMB substrates without compromising cellular viability. This strategy may be applied to the many SR-based biomedical implants and devices where an antibacterial surface is required.
Subject(s)
Bacterial Adhesion , Biofouling , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Biguanides/pharmacology , Biofouling/prevention & control , Esters , Polymers/pharmacology , Silicone ElastomersABSTRACT
Inhibition of biofilm formation and induction of the re-mineralization of damaged dental tissues are two major strategies to combat dental hypersensitivity (DH). However, single component synthetic materials normally cannot fulfil these two functions during the repairing of damaged dental tissues. Here, we report zwitterionic phosphorylcholine based polymers to be a new type of dual functional coating for the repairing of DH. Zwitterionic/phosphonate copolymers, p(DEMMP-co-MPC), bearing varied zwitterionic contents (95 and 75 mol%) were prepared through conventional radical copolymerization. 1H NMR spectroscopy clearly indicated the precise preparation of the copolymers. The copolymers can be easily coated on dentine substrates based on the high affinity between the phosphonate group and the calcium phosphate minerals of the dentine substrates, as evidenced by XPS and water contact angle measurements. Antifouling evaluations indicated that zwitterionic coating can efficiently inhibit protein adsorption (BSA, egg white, and milk, by 85%) and bacterial adhesion (by 97.1%) on dentine substrates. Furthermore, in vitro and in vivo experiments consistently indicated that the zwitterionic coating could not only induce the robust re-mineralization of dentine surfaces, but also template the extensive re-mineralization of dentine tubules to a similar level of pristine dentine. Both the antifouling properties and the re-mineralization potency are positively correlated with the content of zwitterionic pMPC in the coating copolymer. These findings may provide the zwitterionic phosphorylcholine based materials to be a promising candidate to treat dental hypersensitivity and other related dental diseases.
Subject(s)
Biofouling , Organophosphonates , Biofouling/prevention & control , Dentin , Phosphorylcholine/chemistry , Polymers/chemistryABSTRACT
Bacterial-associated infection, blood coagulation, and tissue adhesion are severe issues associated with biomedical implants and devices in clinic applications. Here, we report a general strategy to simultaneously tackle these issues on polyurethane (PU)-based substrates. Taking advantage of reversible addition-fragmentation chain transfer (RAFT) polymerization, well-defined zwitterionic/active ester block polymers (pSBMA-b-pNHSMA) with an identical pNHSMA segment (polymerization degree of 15) but varied zwitterionic pSBMA segments (polymerization degrees of 40 and 100) were precisely prepared. The pSBMA-b-pNHSMA block polymers could be easily covalently constructed on PU substrates that were pretreated with a polydopamine coating based on highly efficient anime-active ester chemistry, as evidenced by the water contact angle and XPS tests. The relationship between the length of pSBMA segments in the coating and the antifouling ability of PU substrates was established. The results indicated that block polymers with a pSBMA segment of 40 repeat units could significantly prevent protein adsorption, bacterial/platelet adhesion, and cell attachment on PU substrates within 24 h, while a longer pSBMA segment (repeat units of 100) could endow long-term antibacterial (14 days without biofilm formation) and anti-cell attachment (5 days without cell attachment) properties to the PU substrates. Furthermore, the coating significantly improved the surface lubricating property of PU substrates without compromising on the mechanical property. This strategy may find many applications in PU-based implants and devices.
Subject(s)
Esters , Polyurethanes , Bacterial Adhesion , Polymers/chemistry , Polyurethanes/chemistry , Surface PropertiesABSTRACT
Atherosclerosis remains the main cause of death and disability, as well as a leading cause of coronary arterial disease. Inflammation is one of the pathogenic factors of arteriosclerosis; however, the current treatments based on lowering the level of inflammation in the plaque tissue of patients with atherosclerosis are not clinically used. Herein, we hypothesize that αvß3 receptor affinity and low pH sensitivity may be regarded as a valid therapeutic strategy for targeting sites of atherosclerosis according to the microenvironments of inflammation. To prove this tentative hypothesis, an acid-labile material polyketal named PK3 was synthesized, and the cRGDfc peptide was used to modify nanoparticles composed of poly(lactide-co-glycolide) (PLGA), lecithin, and PK3, loaded with the anti-atherosclerotic drug rapamycin (RAP). The nanoparticles were prepared using an O/W method and then characterized, which showed an appropriate particle size and fulfilling responsive behaviors. In vitro release studies and stability tests showed that these nanoparticles can be effectively internalized by human umbilical vein endothelial cells (HUVEC), and also show a good in vitro anti-inflammatory effect. After intravenous (i.v.) injection, RGD targeted by pH-responsive nanotherapy (RAP-Nps-RGD) may be accumulated at the plaque site in ApoE-/- mice with atherosclerosis and can effectively attenuate plaque progression compared to other formulations. Moreover, its good safety profile and biocompatibility have been revealed in both in vitro and in vivo estimations. Accordingly, the prospect of nanoparticles responsive to the inflammatory microenvironment for preventing atherosclerotic through inflammation modulation provides great feasibility for the administration of alternate drug molecules to inflamed sites to slow down the process of arteriosclerosis.
Subject(s)
Atherosclerosis , Nanoparticles , Animals , Atherosclerosis/drug therapy , Human Umbilical Vein Endothelial Cells , Humans , Inflammation/drug therapy , Mice , Nanoparticles/chemistry , Oligopeptides/therapeutic use , Sirolimus/pharmacology , Sirolimus/therapeutic useABSTRACT
A novel boronic acid and carboxyl-modified glucose molecularly imprinted polymer were prepared through suspension polymerization, which is based on 1.0 mmol glucose as a template, 1.2 mmol methacrylamidophenylboronic acid, and 6.8 mmol methacrylic acids as monomers, 19 mmol ethyleneglycol dimethacrylate, and 1 mmol methylene-bis-acrylamide as crosslinkers. The prepared glucose-molecularly imprinted polymer had a particle size of 25-70 µm, and was thermally stable below 215°C, with a specific surface area of 174.82 m2/ g and average pore size of 9.48 nm. The best selectivity between glucose and fructose was 2.71 and the maximum adsorption capacity of glucose- molecularly imprinted polymer was up to 236.32 mg/ g which was consistent with the Langmuir adsorption model. The similar adsorption abilities in six successive runs and the good desorption rate (99.4%) verified glucose-molecularly imprinted polymer could be reused. It was successfully used for extracting glucose from cellulose hydrolysis. The adsorption amount of glucose was 2.61 mg/mL and selectivity between glucose and xylose reached 4.12. A newly established chromatography (glucose-molecularly imprinted polymer) mediated hollow fiber membrane method in time separated pure glucose from cellulose hydrolysates on a large scale, and purified glucose solution with a concentration of 3.84 mg/mL was obtained, which offered a feasible way for the industrial production of glucose from cellulose hydrolysates.
Subject(s)
Molecular Imprinting , Adsorption , Boronic Acids , Cellulose , Chromatography , Glucose , Hydrolysis , Molecularly Imprinted Polymers , Plant Extracts/chemistry , Polymers/chemistryABSTRACT
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.
Subject(s)
Hypoglycemic Agents/pharmacology , Liraglutide/pharmacology , Nanoparticle Drug Delivery System/chemistry , Animals , Biological Transport , Caco-2 Cells , Cell Survival/drug effects , Chemistry, Pharmaceutical , Drug Carriers/chemistry , Drug Liberation , Humans , Hypoglycemic Agents/administration & dosage , Hypoglycemic Agents/pharmacokinetics , Intestinal Absorption/drug effects , Intestinal Absorption/physiology , Lipids/chemistry , Liraglutide/administration & dosage , Liraglutide/pharmacokinetics , Mucus/drug effects , Particle Size , Phosphatidylcholines/chemistry , Polylactic Acid-Polyglycolic Acid Copolymer/chemistry , Random Allocation , Rats , Rats, Sprague-Dawley , Surface PropertiesABSTRACT
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.
Subject(s)
Exosomes , Milk , Animals , Drug Carriers/chemistry , Drug Delivery Systems/methods , Exosomes/chemistry , Liraglutide/metabolism , Liraglutide/pharmacology , Peptides/metabolismABSTRACT
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.
ABSTRACT
With ideal optical properties, semiconducting polymer quantum dots (SPs) have become a research focus in recent years; a considerable number of studies have been devoted to the application of SPs in non-invasive and biosafety phototherapy with near-infrared (NIR) lasers. Nevertheless, the relatively poor stability of SPs in vitro and in vivo remains problematic. PCPDTBT was chosen to synthesize photothermal therapy (PTT) and photodynamic therapy (PDT) dual-model SPs, considering its low band gap and desirable absorption in the NIR window. For the first time, cetrimonium bromide was used as a stabilizer to guarantee the in vitro stability of SPs, and as a template to prepare SP hybrid mesoporous silica nanoparticles (SMs) to achieve long-term stability in vivo. The mesoporous structure of SMs was used as a reservoir for the hypoxia-activated prodrug Tirapazamine (TPZ). SMs were decorated with polyethylene glycol-folic acid (SMPFs) to specifically target activated macrophages in rheumatoid arthritis (RA). Upon an 808 nm NIR irradiation, the SMPFs generate intracellular hyperthermia and excessive singlet oxygen. Local hypoxia caused by molecular oxygen consumption simultaneously activates the cytotoxicity of TPZ, which effectively kills activated macrophages and inhibits the progression of arthritis. This triple PTT-PDT-chemo synergistic treatment suggests that SMPFs realize the in vivo application of SPs and may be a potential nano-vehicle for RA therapy with negligible side-toxicity.