Showing papers on "Drug carrier published in 2017"

Applications of nanoparticle systems in drug delivery technology

Abstract: The development of nanoparticle-based drug formulations has yielded the opportunities to address and treat challenging diseases. Nanoparticles vary in size but are generally ranging from 100 to 500 nm. Through the manipulation of size, surface characteristics and material used, the nanoparticles can be developed into smart systems, encasing therapeutic and imaging agents as well as bearing stealth property. Further, these systems can deliver drug to specific tissues and provide controlled release therapy. This targeted and sustained drug delivery decreases the drug related toxicity and increase patient’s compliance with less frequent dosing. Nanotechnology has proven beneficial in the treatment of cancer, AIDS and many other disease, also providing advancement in diagnostic testing.

Graphene Quantum Dots-Capped Magnetic Mesoporous Silica Nanoparticles as a Multifunctional Platform for Controlled Drug Delivery, Magnetic Hyperthermia, and Photothermal Therapy.

Abstract: A multifunctional platform is reported for synergistic therapy with controlled drug release, magnetic hyperthermia, and photothermal therapy, which is composed of graphene quantum dots (GQDs) as caps and local photothermal generators and magnetic mesoporous silica nanoparticles (MMSN) as drug carriers and magnetic thermoseeds. The structure, drug release behavior, magnetic hyperthermia capacity, photothermal effect, and synergistic therapeutic efficiency of the MMSN/GQDs nanoparticles are investigated. The results show that monodisperse MMSN/GQDs nanoparticles with the particle size of 100 nm can load doxorubicin (DOX) and trigger DOX release by low pH environment. Furthermore, the MMSN/GQDs nanoparticles can efficiently generate heat to the hyperthermia temperature under an alternating magnetic field or by near infrared irradiation. More importantly, breast cancer 4T1 cells as a model cellular system, the results indicate that compared with chemotherapy, magnetic hyperthermia or photothermal therapy alone, the combined chemo-magnetic hyperthermia therapy or chemo-photothermal therapy with the DOX-loaded MMSN/GQDs nanosystem exhibits a significant synergistic effect, resulting in a higher efficacy to kill cancer cells. Therefore, the MMSN/GQDs multifunctional platform has great potential in cancer therapy for enhancing the therapeutic efficiency.

pH-Sensitive Delivery Vehicle Based on Folic Acid-Conjugated Polydopamine-Modified Mesoporous Silica Nanoparticles for Targeted Cancer Therapy

Abstract: In this study, we introduced a targeting polymer poly(ethylene glycol)–folic acid (PEG–FA) on the surface of polydopamine (PDA)-modified mesoporous silica nanoparticles (MSNs) to develop the novel nanoparticles (NPs) MSNs@PDA–PEG–FA, which were employed as a drug delivery system loaded with doxorubicin (DOX) as a model drug for cervical cancer therapy. The chemical structure and properties of these NPs were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, N2 adsorption/desorption, dynamic light scattering-autosizer, thermogravimetric analysis, and Fourier transform infrared spectroscopy. The pH-sensitive PDA coating served as a gatekeeper. The in vitro drug release experiments showed pH-dependent and sustained drug release profiles that could enhance the therapeutic anticancer effect and minimize potential damage to normal cells due to the acidic microenvironment of the tumor. These MSNs@PDA–PEG–FA achieved significantly high targeting efficiency, which was demonstrated...

Mesoporous Silica Nanoparticles as Drug Delivery Vehicles in Cancer

Abstract: Even though cancer treatment has improved over the recent decades, still more specific and effective treatment concepts are mandatory. Surgical removal is not always possible, metastases are challenging and chemo- and radiotherapy can not only have severe side-effects but also resistances may occur. To cope with these challenges more efficient therapies with fewer side-effects are required. One promising approach is the use of drug delivery vehicles. Here, mesoporous silica nanoparticles (MSN) are discussed as biodegradable drug carrier to improve efficacy and reduce side-effects. MSN excellently fulfill the criteria for nanoparticulate carriers: their distinct structure allows high loading capacity and a plethora of surface modifications. MSN synthesis permits fine-tuning of particle and pore sizes. Moreover, drug release can be tailored through various gatekeeper systems which are for example pH-sensitive or redox-sensitive. Furthermore, MSN can either enter tumors passively by the enhanced permeability and retention effect or can be actively targeted by various ligands. PEGylation prolongs circulation time and availability. A huge advantage of MSN is their explicitly low toxic profile in vivo. Yet, clinical translation remains challenging. Overall, mesoporous silica nanoparticles are a promising tool for innovative, more efficient and safer cancer therapies.

Stimuli-responsive liposomes for drug delivery.

Abstract: The ultimate goal of drug delivery is to increase the bioavailability and reduce the toxic side effects of the active pharmaceutical ingredient (API) by releasing them at a specific site of action. In the case of antitumor therapy, association of the therapeutic agent with a carrier system can minimize damage to healthy, nontarget tissues, while limit systemic release and promoting long circulation to enhance uptake at the cancerous site due to the enhanced permeation and retention effect (EPR). Stimuli-responsive systems have become a promising way to deliver and release payloads in a site-selective manner. Potential carrier systems have been derived from a wide variety of materials, including inorganic nanoparticles, lipids, and polymers that have been imbued with stimuli-sensitive properties to accomplish triggered release based on an environmental cue. The unique features in the tumor microenvironment can serve as an endogenous stimulus (pH, redox potential, or unique enzymatic activity) or the locus of an applied external stimulus (heat or light) to trigger the controlled release of API. In liposomal carrier systems triggered release is generally based on the principle of membrane destabilization from local defects within bilayer membranes to effect release of liposome-entrapped drugs. This review focuses on the literature appearing between November 2008-February 2016 that reports new developments in stimuli-sensitive liposomal drug delivery strategies using pH change, enzyme transformation, redox reactions, and photochemical mechanisms of activation. WIREs Nanomed Nanobiotechnol 2017, 9:e1450. doi: 10.1002/wnan.1450 For further resources related to this article, please visit the WIREs website.

A Drug‐Self‐Gated Mesoporous Antitumor Nanoplatform Based on pH‐Sensitive Dynamic Covalent Bond

Abstract: To achieve on-demand drug release, mesoporous silica nanocarriers as antitumor platforms generally need to be gated with stimuli-responsive capping agents. Herein, a “smart” mesoporous nanocarrier that is gated by the drug itself through a pH-sensitive dynamic benzoic–imine covalent bond is demonstrated. The new system, which tactfully bypasses the use of auxiliary capping agents, could also exhibit desirable drug release at tumor tissues/cells and enhanced tumor inhibition. Moreover, a facile dynamic PEGylation via benzoic–imine bond further endows the drug-self-gated nanocarrier with tumor extracellular pH-triggered cell uptake and improves therapeutic efficiency in vivo. In short, the paradigm shift in capping agents here will simplify mesoporous nanomaterials as intelligent drug carriers for cancer therapy. Moreover, the self-gated strategy in this work also shows general potential for self-controlled delivery of natural biomolecules, for example, DNA/RNA, peptides, and proteins, due to their intrinsic amino groups.

Multifunctional Bacteria-Driven Microswimmers for Targeted Active Drug Delivery

Abstract: High-performance, multifunctional bacteria-driven microswimmers are introduced using an optimized design and fabrication method for targeted drug delivery applications. These microswimmers are made of mostly single Escherichia coli bacterium attached to the surface of drug-loaded polyelectrolyte multilayer (PEM) microparticles with embedded magnetic nanoparticles. The PEM drug carriers are 1 μm in diameter and are intentionally fabricated with a more viscoelastic material than the particles previously studied in the literature. The resulting stochastic microswimmers are able to swim at mean speeds of up to 22.5 μm/s. They can be guided and targeted to specific cells, because they exhibit biased and directional motion under a chemoattractant gradient and a magnetic field, respectively. Moreover, we demonstrate the microswimmers delivering doxorubicin anticancer drug molecules, encapsulated in the polyelectrolyte multilayers, to 4T1 breast cancer cells under magnetic guidance in vitro. The results reveal th...

pH-Responsive carriers for oral drug delivery: challenges and opportunities of current platforms

Abstract: Oral administration is a desirable alternative of parenteral administration due to the convenience and increased compliance to patients, especially for chronic diseases that require frequent administration. The oral drug delivery is a dynamic research field despite the numerous challenges limiting their effective delivery, such as enzyme degradation, hydrolysis and low permeability of intestinal epithelium in the gastrointestinal (GI) tract. pH-Responsive carriers offer excellent potential as oral therapeutic systems due to enhancing the stability of drug delivery in stomach and achieving controlled release in intestines. This review provides a wide perspective on current status of pH-responsive oral drug delivery systems prepared mainly with organic polymers or inorganic materials, including the strategies used to overcome GI barriers, the challenges in their development and future prospects, with focus on technology trends to improve the bioavailability of orally delivered drugs, the mechanisms of drug release from pH-responsive oral formulations, and their application for drug delivery, such as protein and peptide therapeutics, vaccination, inflammatory bowel disease (IBD) and bacterial infections.

Composite CD-MOF nanocrystals-containing microspheres for sustained drug delivery

Abstract: Metal–organic frameworks (MOFs), which are typically embedded in polymer matrices as composites, are emerging as a new class of carriers for sustained drug delivery. Most of the MOFs and the polymers used so far in these composites, however, are not pharmaceutically acceptable. In the investigation reported herein, composites of γ-cyclodextrin (γ-CD)-based MOFs (CD-MOFs) and polyacrylic acid (PAA) were prepared by a solid in oil-in-oil (s/o/o) emulsifying solvent evaporation method. A modified hydrothermal protocol has been established which produces efficiently at 50 °C in 6 h micron (5–10 μm) and nanometer (500–700 nm) diameter CD-MOF particles of uniform size with smooth surfaces and powder X-ray diffraction patterns that are identical with those reported in the literature. Ibuprofen (IBU) and Lansoprazole (LPZ), both insoluble in water and lacking in stability, were entrapped with high drug loading in nanometer-sized CD-MOFs by co-crystallisation (that is more effective than impregnation) without causing MOF crystal degradation during the loading process. On account of the good dispersion of drug-loaded CD-MOF nanocrystals inside polyacrylic acid (PAA) matrices and the homogeneous distribution of the drug molecules within these crystals, the composite microspheres exhibit not only spherical shapes and sustained drug release over a prolonged period of time, but they also demonstrate reduced cell toxicity. The cumulative release rate for IBU (and LPZ) follows the trend: IBU-γ-CD complex microspheres (ca. 80% in 2 h) > IBU microspheres > IBU-CD-MOF/PAA composite microspheres (ca. 50% in 24 h). Importantly, no burst release of IBU (and LPZ) was observed from the CD-MOF/PAA composite microspheres, suggesting an even distribution of the drug as well as strong drug carrier interactions inside the CD-MOF. In summary, these composite microspheres, composed of CD-MOF nanocrystals embedded in a biocompatible polymer (PAA) matrix, constitute an efficient and pharmaceutically acceptable MOF-based carrier for sustained drug release.

Nano carriers for drug transport across the blood–brain barrier

Abstract: Effective therapy lies in achieving a therapeutic amount of drug to the proper site in the body and then maintaining the desired drug concentration for a sufficient time interval to be clinically effective for treatment. The blood-brain barrier (BBB) hinders most drugs from entering the central nervous system (CNS) from the blood stream, leading to the difficulty of delivering drugs to the brain via the circulatory system for the treatment, diagnosis and prevention of brain diseases. Several brain drug delivery approaches have been developed, such as intracerebral and intracerebroventricular administration, intranasal delivery and blood-to-brain delivery, as a result of transient BBB disruption induced by biological, chemical or physical stimuli such as zonula occludens toxin, mannitol, magnetic heating and ultrasound, but these approaches showed disadvantages of being dangerous, high cost and unsuitability for most brain diseases and drugs. The strategy of vector-mediated blood-to-brain delivery, which involves improving BBB permeability of the drug-carrier conjugate, can minimize side effects, such as being submicrometre objects that behave as a whole unit in terms of their transport and properties, nanomaterials, are promising carrier vehicles for direct drug transport across the intact BBB as a result of their potential to enter the brain capillary endothelial cells by means of normal endocytosis and transcytosis due to their small size, as well as their possibility of being functionalized with multiple copies of the drug molecule of interest. This review provids a concise discussion of nano carriers for drug transport across the intact BBB, various forms of nanomaterials including inorganic/solid lipid/polymeric nanoparticles, nanoemulsions, quantum dots, nanogels, liposomes, micelles, dendrimers, polymersomes and exosomes are critically evaluated, their mechanisms for drug transport across the BBB are reviewed, and the future directions of this area are fully discussed.

Magnetofluorescent Carbon Dots Derived from Crab Shell for Targeted Dual-Modality Bioimaging and Drug Delivery

Abstract: We propose a one-pot microwave-assisted pyrolysis method for fabrication of magnetofluorescent carbon quantum dots (MFCQDs), using a combination of waste crab shell and three different transition-metal ions, Gd3+, Mn2+, and Eu3+, referred to as Gd@CQDs, Mn@CQDs, and Eu@CQDs, respectively. Chitin from waste crab shell acted not only as a carbon source but also as a chelating ligand to form complexes with transition-metal ions. Gd@CQDs exhibited a high r1 relaxivity of 4.78 mM–1·s–1 and a low r2/r1 ratio of 1.33, suggesting that they show excellent potential as a T1 contrast agent. Mn@CQDs and Eu@CQDs showed high r2 relaxivity values of 140.7 and 28.32 mM–1·s–1, respectively, suggesting their potential for use as T2 contrast agents. Further conjugation of Gd@CQDs with folic acid (FA) enabled specific targeting to folate receptor-positive HeLa cells, as confirmed via in vitro magnetic resonance and fluorescence imaging. Doxorubicin (DOX) was selected as a model drug for conjugation with FA-Gd@CQDs. The as-pr...

Recent advances on liposomal nanoparticles: synthesis, characterization and biomedical applications.

Abstract: Liposome is a new nanostructure for the encapsulation and delivery of bioactive agents. There are a lot of bioactive materials that could be incorporated into liposomes including cosmetics, food ingredients, and pharmaceuticals. Liposomes possess particular properties such as biocompatibility, biodegradability; accompanied by their nanosize they have potential applications in nanomedicine, cosmetics, and food industry. Nanoliposome technology offers thrilling chances for food technologists in fields including encapsulation and controlled release of food ingredients, also improved bioavailability and stability of sensitive materials. Amid numerous brilliant new drug and gene delivery systems, liposomes provide an advanced technology to carry active molecules to the specific site of action, and now days, various formulations are in clinical use. In this paper, we provide review of the main physicochemical properties of liposomes, current methods of the manufacturing and introduce some of their usage in food nanotechnology as carrier vehicles of nutrients, enzymes, and food antimicrobials and their applications as drug carriers and gene delivery agents in biomedicine.

Evaluation of mesoporous silica nanoparticles for oral drug delivery – current status and perspective of MSNs drug carriers

Abstract: The oral pathway is considered as the most common method for drug administration, although many drugs, especially the highly pH- and/or enzymatic biodegradable peptide drugs, are very difficult to formulate and achieve a good intestinal absorption. Efficient systematic absorption of an active substance, delivered via oral ingestion, is only achievable if the drug (1) is substantially present as a solution in the gastrointestinal tract, (2) is able to penetrate through the intestinal mucus, (3) overcomes the different gastrointestinal barriers, and (4) provides an effective therapeutic dose. Therefore, optimization of oral bioavailability of poorly-soluble drugs still remains a significant challenge for the pharmaceutical industry. Even though numerous conventional drug carriers have successfully solved some of the issues related to oral delivery of poorly-soluble drugs, only few of them met commercialization requirements. These drawbacks have led the scientific world to reconsider its approaches toward targeted drug delivery systems and researchers started looking for alternative vectorized carriers. In this area, nanoparticle-based materials have several significant advantages over free and non-formulated drugs. For example, nanosized porous silica carriers allow for more sustained and controlled drug release or improved oral bioavailability. Thus, in the present review, we will highlight the most important features of nanostructured silica drug carriers, such as particle size, particle shape, surface roughness or surface functionalization, and underline the key advantages of these nanosupports. In particular, this article will discuss recent progress and challenges in the area of mesoporous silica nanocarriers used for oral drug delivery. Additional emphasis will be set on the biological and chemical features of the gastrointestinal tract as well as currently tested nanoformulations and strategies to avoid drug degradation in the gastrointestinal environment.