As one of the traditional computer simulation techniques, molecular simulation can intuitively display and quantify molecular structure and explain experimental phenomena from the microscopic molecular level. When the simulation system increases, the amount of calculation will also increase, which will cause a great burden on the simulation system. Coarse-grained molecular dynamics is a method of mesoscopic molecular simulation, which can simplify the molecular structure and improve computational efficiency, as a result, coarse-grained molecular dynamics is often used when simulating macromolecular systems such as drug carrier materials. In this article, we reviewed the recent research results of using coarse-grained molecular dynamics to simulate drug carriers, in order to provide a reference for future pharmaceutical preparation research and accelerate the entry of drug research into the era of precision drug design.
Molecular Dynamics Simulation ; Drug Carriers

With the research and application of the new ultrasound microbubble contrast agents, ultrasonic microbubbles can not only help to image, but they can also be used as genes or drug carriers. The microbubbles as genes or drug carriers can pass across the endothelial cell barrier and release genes and drug under the action of ultrasound field, which achieve target treatment effect. Based on the relevant materials, the bioeffects, early successes with gene and drug delivery, and potential clinical applications are reviewed.
Drug Carriers ; Drug Delivery Systems ; Genetic Vectors ; Microbubbles ; Nanostructures ; Ultrasonics

Modern drug delivery system demands high therapeutic efficacy and low toxicity which depends on efficient intracellular transportation of therapeutics to specific organisms, cells, even targeted organelles such as cytosol, nucleus, mitochondria, lysosome and endoplasmic reticulum. Intracellular barriers which prevent drug molecules accessing to their targets mainly include cell membrane, lysosomal degradation and the endomembrane system. Nanocarriers can preserve the bioactivities of protein, enzyme and DNA, and also they are easy to be modified and functionalized. In this paper, we summarized the intracellular fate of nanocarriers, especially how to bypass intracellular barriers and then target cytosol, nucleus, mitochondria, lysosome and endoplasmic reticulum by pharmaceutical modifications.
Animals ; Drug Carriers ; Drug Delivery Systems ; Humans ; Nanoparticles ; Organelles

Cancer is one of the most important diseases threatening human health. Frequently-used traditional cancer treatment methods, like radiotherapy, chemotherapy and surgery, have serious toxic side effects and limitations. The widely-used drug delivery carriers (liposomes, nanoparticles, etc.) have also possessed many issues such as drug leakage and incomplete loading in the late clinical stage. Currently, using tumor-targeting vectors to deliver anti-tumor drugs or small molecules is one of the promising strategies for mediating safe and effective tumor therapy. In recent years, bacterial-derived non-replicating minicells, which are nanoscale non-nucleated cells produced during abnormal bacterial division, have got more and more attention. With a diameter of 200-400 nm, minicells have a large drug loading capacity. Meanwhile, the surface of minicells are able to be modified to load the assembly of antibodies/ligands that bind to tumor cell surface specific antigens or receptors, which can significantly improve tumor targeting of minicells. This tumor-targeting nanomaterials of minicells not only are used to deliver anti-tumor chemotherapeutic drugs, functional nucleic acids or plasmids encoding functional small molecules to mammalian cells, but also greatly increase drug loading and reduce drug penetration. Thus, the use of minicells combining with chemical therapy could help reduce the toxicity and maximize the effectiveness of the drug in the body. This paper summarizes the research and development of production purification, drug loading, tumor cells targeting, and internalization process of minicells, as well as its use in the delivery of anti-tumor drugs, to provide some information for the development and utilization of minicell carriers.
Animals ; Drug Carriers ; Drug Delivery Systems ; Humans ; Nanoparticles ; Neoplasms ; Plasmids

OBJECTIVE: The purpose of this study is to investigate the effects of different drying methods on the physical properties and drug delivery of chitosan microspheres. METHODS: Three types of drying methods were utilized, including air drying and freeze drying after freezing at -20 ℃ (slow cooling) and at -80 ℃ (fast cooling). The physical properties of microspheres were characterized. Utilizing bovine serum albumin (BSA) as the model drug, the in-vitro release behaviors of drug-loaded beads were investigated. RESULTS: By comparing the physical properties of the different drying methods, the microspheres' diameters, porosities, and surface area were observed to increase successively from air drying and slow cooling to fast cooling, whereas the pore size and the swelling and degradation rates varied. The drug-loading experiments revealed that the loading capacity of air-dried microspheres was the lowest and the release rate was the slowest. Although the loading capacity of fast cooling microspheres was high, an obvious burst release was observed. The loading capacity of slow cooling microspheres was similar to that of the fast cooling microspheres and the loaded BSA can be released continuously. CONCLUSIONS The results indicate that different drying methods can affect the physical properties of chitosan microspheres, which further influence drug loading and release.
Chitosan ; Drug Carriers ; Drug Compounding ; Microspheres ; Particle Size

Exosomes are nanoscale vectors with a diameter of 30~100 nm secreted by living cells, and they are important media for intercellular communication. Recent studies have demonstrated that exosomes can not only serve as biomarkers for diagnosis, but also have great potential as natural drug delivery vectors. Exosomes can be loaded with therapeutic cargos, including small molecules, proteins, and oligonucleotides. Meanwhile, the unique biological compatibility, high stability, and tumor targeting of exosomes make them attractive in future tumor therapy. Though exosomes can effectively deliver bioactive materials to receptor cells, there is a wide gap between our current understanding of exosomes and their application as ideal drug delivery systems. In this review, we will briefly introduce the function and composition of exosomes, and mainly summarize the potential advantages and challenges of exosomes as drug carriers. Finally, this review is expected to provide new ideas for the development of exosome-based drug delivery systems.
Biomarkers ; Drug Carriers ; Drug Delivery Systems ; Exosomes ; Humans ; Neoplasms

In this study,a nano drug delivery system GA-DTX-NGO which could be used for liver tumor photothermal and chemotherapy was prepared and characterized,with docetaxel(DTX) as model drug,glycyrrhetinic acid(GA) as the target molecule,and nano graphene oxide(NGO) as the photosensitizer. Firstly,GA-NGO nanocomposites were synthesized by the amidation reaction,and then GA-DTX-NGO was prepared by ultrasonic dispersion method. The encapsulation efficiency and drug loading ratio were determined by high performance liquid chromatography(HPLC) and ultracentrifugation; the morphology was observed by transmission electron microscopy(TEM). The photothermal conversion test was carried out by laser irradiation at 808 nm and the drug release test in vitro was performed using reverse dialysis. Finally,the effect of GA-DTX-NGO on SMMC-7721 liver tumor cells proliferation was determined by using MTT assay. The results showed that GA-DTX-NGO had good water dispersibility,and TEM results showed a lamellar structure with about 200 nm in diameter. The encapsulation efficiency and drug loading ratio of GA-DTX-NGO were(98. 89 ± 0. 07) % and(64. 74±0. 26) %,respectively. GA-DTX-NGO had strong photothermal conversion performance under 808 nm of laser irradiation. The drug release test in vitro results showed GA-DTX-NGO had obvious sustained-release effects and temperature-dependent release characteristics. The results of cell assay showed that GA-DTX-NGO could effectively inhibit the proliferation of SMMC 7721 cells in a concentration-and time-dependent manner,and the inhibitory effect was enhanced after combination with the near-infrared therapy. In conclusion,the preparation process of GA-DTX-NGO nano drug delivery system is feasible,which could provide some theoretical basis for further study of photothermal and chemotherapy on liver tumor.
Antineoplastic Agents ; Drug Carriers ; Drug Delivery Systems ; Glycyrrhetinic Acid ; Graphite

The application of intraocular drug delivery is usually limited due to special anatomical and physiological barriers, and the elimination mechanisms in the eye. Organic nano-drug delivery carriers exhibit excellent adhesion, permeability, targeted modification and controlled release abilities to overcome the obstacles and improve the efficiency of drug delivery and bioavailability. Solid lipid nanoparticles can entrap the active components in the lipid structure to improve the stability of drugs and reduce the production cost. Liposomes can transport hydrophobic or hydrophilic molecules, including small molecules, proteins and nucleic acids. Compared with linear macromolecules, dendrimers have a regular structure and well-defined molecular mass and size, which can precisely control the molecular shape and functional groups. Degradable polymer materials endow nano-delivery systems a variety of size, potential, morphology and other characteristics, which enable controlled release of drugs and are easy to modify with a variety of ligands and functional molecules. Organic biomimetic nanocarriers are highly optimized through evolution of natural particles, showing better biocompatibility and lower toxicity. In this article, we summarize the advantages of organic nanocarriers in overcoming multiple barriers and improving the bioavailability of drugs, and highlight the latest research progresses on the application of organic nanocarriers for treatment of ocular diseases.
Drug Carriers ; Delayed-Action Preparations ; Drug Delivery Systems ; Nanoparticles/chemistry*

Lactoferrin (Lf) is one of the food protein belonged to the innate immune system. Apart from its main biological function of binding and transport of iron ions, lactoferrin also has many other functions and properties such as antibacterial, antiviral, antiparasitic, catalytic, anti-cancer, anti-allergic and radioprotecting. Lf is usually used as additives of food and cosmetics. The research of lactoferrin has been increasingly reported, and the application of lactoferrin as a drug carrier has drawn extensive attention over the recent year. In this paper, researches of lactoferrin as drug carriers are classified and summarized in brain targeting, liver tumor targeting, lung tumor targeting and oral delivery systems according to their different characteristics.
Administration, Oral ; Brain ; Drug Carriers ; Humans ; Lactoferrin ; chemistry ; Neoplasms

Nowadays, there are more and more researches on characters and applications of polycaprolactone (PCL). This paper reviews the researches of polycaprolactone, including its synthesis, physical and chemical properties, biodegradation, absorption properties, and its applications in clinical use and drug delivery systems. PCL can be from open ring polymerizaion. It is a kind of semi-crystalline polymer, and has good flexibility. The degradation reaction of PCL is hydrolysis. PCL is not cumulated in the body, and can be totally excreted. It can be used as suture, material for fixation of bone fracture, vector of drug, etc. PCL is widely used in medical area because of its safety, low toxicity, biodegradability.
Biodegradation, Environmental ; Drug Carriers ; Polyesters ; chemical synthesis ; chemistry ; metabolism ; Sutures