جستجوی مقالات مرتبط با کلیدواژه « drug delivery » در نشریات گروه « مهندسی شیمی، نفت و پلیمر »

Today, cancer is the second leading cause of death worldwide. Covalent Organic Frameworks (COFs) are new emerging 2 or 3D porous nanomaterials that have attracted tremendous attention. These materials are composed of light elements including carbon, boron, hydrogen, which are connected with strong covalent bonds. Due to their low density, high surface area, and intrinsic porosity, suitable crystallinity, and high thermal stability, these materials have become a suitable candidate for many applications such as sensors, drug delivery, separation, catalysts, and adsorption. Due to their porosity and high loading capacity, COFs has the ability to encapsulate various types of therapeutic agents. These materials can modify with different functional groups to achieve targeted drug delivery and increase biocompatibility. Also, their metal-free nature has caused COFs to have a good perspective in drug delivery applications and have shown low cytotoxicity in in-vitro studies. In this review, different types of COFs and a number of studies conducted on these nanomaterials for drug delivery applications have been reviewed. In the last part, the upcoming challenges in this area have been discussed.

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 In recent years, scientists and researchers have been looking for new and advanced materials for use in various fields, including drug delivery and biotechnology. One of the attractive  materials that has been considered in this field is chitosan-based bionanocomposite hydrogel beads. Chitosan-based bionanocomposite hydrogel beads have attracted attention as carriers in drug delivery systems due to their inherent properties such as excellent biocompatibility, high swelling, and high storage capacities.

First graphene quantum dots (GQDs) were prepared by the pyrolysis method, and then their magnetic properties were obtained using iron nanoparticles (MGQD). Next they were coated with chitosan hydrogel (CS-MGQD) and finally loaded with methotrexate (MTX/CS-MGQD). This unique combination of the properties of chitosan hydrogel, the magnetic properties of graphene quantum dots, and the ability to adjust drug release has been able to create an important milestone in the field of drug delivery research and the compatibility of drugs with the biological environment. Through various analyses, including FTIR to analyze the spectra of the functional groups, XRD to identify the crystal structure, and SEM to examine the morphology of the samples, the success of the synthesis and formation of the desired compound was confirmed.

The fabricated CS and CS-MGQD hydrogel beads were loaded with about 84% and 64% MTX, respectively. The results of the swelling behavior and drug release behavior showed that the hydrogel beads experience pH-dependent swelling and release of MTX. In addition, investigating the effect of MGQD concentration on swelling behavior and drug release showed that CS-MGQD has favorable stability and controllable drug release in an acid environment. Also, the Weibull kinetic model was found to be the best-fitting model for the release of MTX from CS-MGQD at pH 5. These findings suggest that the prepared magnetic bionanocomposite hydrogel beads have a good potential for pH-sensitive implantable drug delivery in the treatment of cancerous tissue.

Hydrogels are three-dimensional networks of hydrophilic polymers capable of absorbing and retaining significant amounts of fluids, which are also widely applied in wound healing, cartilage tissue engineering, bone tissue engineering, release of proteins, growth factors, and antibiotics. In the past decades, a lot of research has been done to accelerate wound healing. Hydrogel-based scaffolds have been a recurring solution in both cases, although their mechanical stability remains a challenge, some of which have already reached the market. To overcome this limitation, the reinforcement of hydrogels with fibers has been investigated. The structural similarity of hydrogel fiber composites to natural tissues has been a driving force for the optimization and exploration of these systems in biomedicine. Indeed, the combination of hydrogel formation techniques and fiber spinning methods has been very important in the development of scaffold systems with improved mechanical strength and medicinal properties. Hydrogel has the ability to absorb secretions and maintain moisture balance in the wound. In turn, the fibers follow the structure of the extracellular matrix (ECM). The combination of these two structures (fiber and hydrogel ) in a scaffold is expected to facilitate healing by creating a suitable environment by identifying and connecting cells with the moist and breathing space required for healthy tissue formation. Modifying the surface of fibers by physical and chemical methods improves the performance of hydrogel composites containing

In recent years, dendrimers as a new class of polymeric materials have attracted lots of attention due to their unique properties, especially as drug delivery systems. In this process, dendrimers can deliver medicine directly to the affected part of the patient's body. Dendrimers can be defined as macromolecular structures with several advantages, which may undergo changes depending on the chemical nature of the drug to be delivered. Dendrimers can be defined as macromolecular structures with several advantages that depending on the chemical nature of the drug to be delivered, they may change. The reason for the high attention paid to dendrimers in drug delivery is that they have properties such as uniform size, water solubility, modifiable surface performance, high degree of branching, being multivalent, well-defined molecular weight, and available internal cavities. In addition, the high level of control over dendritic architecture distinguishes them as ideal carriers. Also, the use of dendrimers in biomedicine has attracted the attention of many scientists. Biomedicine is one of the main fields of study of dendrimers due to their capacity to improve solubility, uptake, bioavailability and targeted distribution, and their value in diagnosis and treatment. In the last decade, anti-neoplastic research on dendrimers has been widely developed and several types of poly amidoamine (PAMAM) and poly propylene imine (PPI) dendrimer complexes with doxorubicin, paclitaxel, cisplatin, melphalan, and methotrexate have been improved compared to the drug molecule alone.

Hydrogels are three-dimensional networks of hydrophilic polymers capable of absorbing and retaining significant amounts of fluids, which are also widely applied in wound healing, cartilage tissue engineering, bone tissue engineering, release of proteins, growth factors, and antibiotics. In the past decades, a lot of research has been done to accelerate wound healing. Hydrogel-based scaffolds have been a recurring solution in both cases, although their mechanical stability remains a challenge, some of which have already reached the market. To overcome this limitation, the reinforcement of hydrogels with fibers has been investigated. The structural similarity of hydrogel fiber composites to natural tissues has been a driving force for the optimization and exploration of these systems in biomedicine. Indeed, the combination of hydrogel formation techniques and fiber spinning methods has been very important in the development of scaffold systems with improved mechanical strength and medicinal properties. Hydrogel has the ability to absorb secretions and maintain moisture balance in the wound. In turn, the fibers follow the structure of the extracellular matrix (ECM). The combination of these two structures (fiber and hydrogel ) in a scaffold is expected to facilitate healing by creating a suitable environment by identifying and connecting cells with the moist and breathing space required for healthy tissue formation. Modifying the surface of fibers by physical and chemical methods improves the performance of hydrogel composites containing

Organogels are one of the main components of a group of gels that are noncrystalline and viscoelastic in nature and show three-dimensional and cross-linked networks in the organic liquid phase. Applications of organogels include their use in chemistry, pharmaceutical and cosmetic industries, biotechnology and food technology. Unfortunately, in recent years, the use of organogels as drug delivery systems has faced problems due to the toxicity of selective organic solvents. But recently, the synthesis of biocompatible organogels has led to the development of several biomedical and pharmaceutical applications. In this article, hydrogels are briefly reviewed, followed by a more in-depth review of gels that have been investigated for drug delivery. Over the past two decades, organogels have made significant advances as drug delivery matrices. The favorable and impressive performance of organogels is due to their ease of preparation, cost-effectiveness and their ability to have hydrophilic and lipophilic compounds. The ability of organogels to incorporate hydrophilic and hydrophobic compounds into their structure has expanded the use of organogels in various drug delivery systems. Organogels are used as drug delivery platforms to administer the active agent through various routes such as dermal, oral and injectable.

Recently, the use of controlled-radical polymerization methods for the preparation of various polymer materials has received much attention due to the advantages of these methods and the elimination of the disadvantages of radical polymerization. There are many methods for controlled-living radical polymerization, but in general the three main methods for controlled-living radical polymerization are nitric oxide-mediated radical polymerization (NMP), atom transfer radical polymerization (ATRP), and reversible addition fragmentation chain transfer (RAFT). Among these methods, RAFT polymerization has attracted more attention due to its advantages over other methods used in the preparation of polymeric materials, including polymer nanocomposites. Nanocomposites are compounds obtained from a mixture of two or more different materials that are in the form of separate phases and at least one of their components has nanometer dimensions of less than 100 nm. The combination of high surface area in nanoparticles and different functional groups in the polymer can create unique properties in the nanocomposites. Due to these properties, polymer nanocomposites are widely used in various industries, including polymer catalysts, sensors, chemical adsorbents as well as drug delivery nanocarriers. In this article, the preparation of polymer nanocomposites based on various nanoparticles such as carbon, SiO2, Fe3O4, Au and MoS2 nanoparticles through RAFT polymerization and the effectiveness of these nanomaterials in drug delivery have been reviewed.

The feld of drug delivery is a very hot research area as it afects the life of millions of patients every year. Although pharmaceutical agents can be adminisrated in diferent ways, the efectiveness of certain drug delivery sysem (DDS) is directly related to the method of their adminisration. Polyurethanes are one of the mos important classes of polymers, that play an essential role in the development of many diferent biomedical devices due to their exceptional compatibility, mechanical properties and fexibility. Polyurethanes are formed by the reaction reviewed of isocyanates and diols to produce urethane-bonded polymers (-NH-COO-) in their main chain, which is similar to the peptide bonds in the sructure of proteins. Because of this similarity, they have also been used as part of the human body, such as dialysis membranes, intra-aortic balloons, heart valves, temporary scafolds and breas implants. There are many types of polyurethane sructural blocks available that allow the chemical and physical properties of polyurethane to be tailored to their intended applications, especially in the medical and pharmaceutical felds. In this paper, the synthesis and properties of polyurethane, sructure, thermal sability, hardness, solvent resisance, drug delivery, mechanical properties as well as biodegradability and biocompatibility with special emphasis on the application of the polymer in controlled release of drugs and delivery to the target tissue were.

In this study, biocompatible mesoporous silica nanocarriers were synthesized with the regular and uniform pore distribution from natural sources of rice and wheat husk under sol-gel process for sustainable drug delivery to breast cancer cells. The physicochemical properties of nanocarriers were investigated by XRD, FT-IR, SEM and BET analyzes. Nanocarriers obtained from rice and wheat husk had a specific surface area of 741.44 and 630.52 m2/g, respectively, with regular and uniform pore distribution with a size of 2.58 and 3.63 nm. Doxorubicin was loaded as a model drug into the nanocarriers and drug release was evaluated at pH 7.4 and 5.4. The results showed that the drug release rate doubled under acidic conditions which simulating the tumor environment. By examining the cytotoxicity of nanocarriers on the HFF-2 and MCF-7 cell lines, it was found that the nanocarriers have high biocompatibility and prevent the growth and cause to cancerous cells death.

Synthetic micro/nanomotors are functionalized micro/nanoparticles with the ability ofself-propelling motion. Synthetic micro/nanomotors are the mimic of mobile organismslike bacteria in nature. Micro/nanomotors have different types such as fuel required micro/nanomotors and fuel-free ones and various applications. Fuel-free micro/nanomotors movethrough environmental changes like increasing in temperature by heating, magnetic andultrasonic fields, etc. Platinum-based micro/nanomotors are the most common types of micro/nanomotors. Hydrogen peroxide is the fuel utilized in platinum-based micro/nanomotors.The decomposition of hydrogen peroxide fuel on the platinum surface of synthetic micro/nanomotors, supplies the required energy for motion of motors. Platinum-based micro/nanomotors have different structures and geometrics include spherical, stomatocyte, rod,tubular, and shell that that creates various motion mechanisms and speeds. The motionspeed of micro/nanomotors has a wide range of amounts from one micrometer per secondto hundreds micrometers per second. In this review, platinum-based micro/nanomotors andtheir different types have been introduced. In addition, different mechanisms of motioninclude self-electrophoresis, self-diffusiophoresis and bubble-propulsion mechanismshave been discussed. Then, the comparison of velocities in different motion mechanisms,applications of micro-nanomotors and the challenge of using their platinum type in in vivoconditions were also mentioned.

Covalent Organic Frameworks (COFs) are porous crystalline polymers put together by linking light elements such as Carbon, Boron, Oxygen and Silicon through strong covalent bonds that are positioned in 2D or 3D topology. Porous organic materials, exhibit unique features and therefore, they can potentially be used in diverse applications such as catalyst, molecular sensing, drug delivery, and gas storage. Metallic organic frameworks (MOFs) and covalent organic frameworks (COFs) attracted the attention of researchers because of their characteristic properties such as high free surface area, low density, high thermal and chemical stability, and uniformity and high porosity. So far, thousands of new polymer frameworks have been synthesized after discovering the frst structure. In this paper, the latest developments in design, synthesis and various applications of covalent organic frameworks such as gas storage, catalyst, adsorption, enrichment and purifcation of small molecules, optoelectricity, molecular sensing, targeted drug delivery, conductive membranes, novel coatings, and energy storage are discussed.

Nanofiber technology is an exciting research area that has attracted the attention of several researchers as a potential solution to the current challenges in the biomedical field for wound dressing, organ repair, and treatment for osteoporosis. Nanofibrous meshes mimic the porous structure of the natural extracellular matrix (ECM); hence they are advantageous for tissue regeneration and can be used for sustaining the release of encapsulated drug or growth factor. Electrospinning is one of the most common methods for the fabrication of nanofibrous meshes, with very high surface area to volume ratio and porous structure, for various biomedical and tissue engineering applications.  The electrospun meshes can be used for making scaffolds similar in physical structure to that of ECM. The electrospun nanofibers mimic the ECM nano-fibrils and porous structure. In this review, the applications of nanofibers in various biomedical areas such as tissue engineering, drug delivery and wound dressing are summarized. This provides an overview of the development of new materials and techniques to be used in biomedical engineering applications and reliable analytical techniques for their characterization.

Polymeric materials carrying positive and/or negative charges at neutral pH are referred as "polyelectrolytes". Many kinds of materials are considered as polyelectrolytes because they bear ionic groups of positive or negative charges on their surfaces. The interaction between two or more opposite charged polyelectrolytes in solution forms a polyelectrolyte complex (PEC). Polymers used for PEC formation are classified on the basis of origin as natural and synthetic. The worldwide agreement among investigators is that the PEC formation is an entropy-driven phenomenon. The contributing force for the formation of PECs in aqueous solutions is the release of low molecular weight counter ions (which were previously associated with the charged groups on polymer chains) that result in an increase in entropy of the system. PECs have many advantages such as high biodegradability, excellent biocompatibility, non-toxicity, low cost, low energy requirement for their production. There are numerous parameters affecting PEC formation including charge density, molecular weight, and salt concentration, pH of the reaction medium, ionic strength and mixing ratio. This article presents the properties of PEC, mechanism of PEC formation, factors affecting the formation of PEC, different methods for PEC synthesis and application of PECs. PEC is an emerging system for drug delivery to target sites, sustained and thereby prolonging the therapeutic action. They are also used in gene, protein and vaccine delivery, tissue engineering and fabrication of membranes.

The main purpose of this paper is the investigation and study of membrane technology applications in novel drug delivery systems. In recent decades, membrane drug delivery systems have been considered by researchers because of their membrane compatibility with the body, biodegradability, the ability to release the drug at a constant rate and to the amount required for the body. In this research, various types of drug delivery systems using membrane technology including osmotic membrane system, Diffusion controlled membrane systems (implants, patches and pills) and transdermal membrane system (passive diffusion and iontophoresis) were investigated. Moreover, commercial membrane drug delivery systems are presented. Indeed, this research shows the important roles of membrane science and technology in medical applications but also highlights the importance of collaboration of membrane scientists with others (biologists, bioengineers, medical doctors, etc.) in order to address the complicated challenges in this field.

Recently, polymers have shown great potential in biological science. Natural polymers including polysaccharides with bacterial, animal and fungal sources are a good candidate to mimic structure of biological materials such as extracellular matrices. Therefore, they have gained much attentionin therapeutic and tissue engineering applications. Polysaccharides among all natural polymers show promising potential for preparation of nanostructured carriers. Nowadays, nanofilms, nanoparticles, and nanofibers are well known carriers for drug delivery and tissue engineering applications. Gum tragacanth is a natural polymer and a complex carbohydrate including polysaccharide structure. It comprises excellent physical, chemical and biological properties such as thermal and mechanical behavior; biodegradability, biocompatibility, and antimicrobial effect on wound healing and burn infections. Previously, raw gum tragacanth used to be applied locally as a superabsorbent hydrogels, antibacterial nanocapsuls, and mucilage for would healing treatment and deep wound scar. In recent years nanofibers have shown potential in tissue scaffold and mats for delivery of therapeutic drugs. Researchers have developed methods to engineer nanostructured fibers and tuned physical parameters such as diameter, tensile modulus, and degradation properties. In this review some of the recent works on gum tragacanth nanofibers and incorporation with other polymeric materials are discussed. Antimicrobial and would healing characteristics of gum tragacanth is being highlighted.

The main aim in drug delivery systems, is to increase drug bioavailability at specific time and location of the body, the ability to maintain a relatively constant drug concentration in the specific period of time, adjustable release rate of the drug, the ability to deliver multiple drug substances, increasing the efficiency and reducing the side effects on the other non-diseased host tissues. Some therapeutic agents such as proteins/peptides, nucleic acids, anti-carcinogens, and other drugs, used nowadays, may have the drawbacks of low bioavailability, rapid clearance, high toxicity and very harmful side effects. The invention of drug delivery and drug carriers has created a revolution in the treatment of many diseases which is increasing in progress. Phospholipids are compounds with bipolar nature due to the presence of phosphate group, a hydrophilic head and two lipophilic branches. Phospholipids can carry hydrophilic and hydrophobic pharmaceutical compounds in a structure compatible with living cells and serve their penetration in living cells and into the target cell. Phospholipids as surface-active wetting agents cover the surface of crystals to enhance the hydrophilicity of hydrophobic drugs and higher efficiency in drug delivery. In this paper, studies are extended to different kinds of phospholipids, their structures, their sources, physical properties, their complexes with drugs, phospholipid micelles and effective factors in their selection for drug delivery systems.

Taking a drug/medicine by conventional methods (digestive and indigestive) by patients leads to the release of high dosage of drug in their body. The concentration of drug decreases after a few hours and the patients need to take the next dose again, and such cycle continues. By development of nanoscience and its technology, some new controlled drug delivery systems have been proposed instead. These new systems are expected to improve patient's convenience and compliance, because they are made of biocompatible and biodegradable polymers in controlling drug delivery in the body. Biodegradable polymers can be classified as synthetic and natural polymers with their own specific features. To control the delivery of the drugs, a blend of polymers can be used. In this paper, the effect of blended synthetic biodegradable polymers on controlled drug delivery by electrospun nanofiber is reviewed.

Current research suggests that carbon nanotubes (CNTs) as biomaterials have immense potential for applications in regenerative medicine. The focus of regenerative medicine is on developing methods that can be applied to create functional tissues, to repair or replace tissues/organs lost due to trauma or diseases. In this respect, the structural and mechanical properties of CNTs make them applicable for use as composites for tissue engineering. CNTs can act as delivery vehicles for drugs and gene therapy and thus are suitable for therapeutics in regenerative medicine. The external carbon sheath of the CNTs can be functionalized for usein targeting, drug delivery, and as imaging agents. Further intrinsic physical properties of carbon nanotubes can be harnessed for therapeutics and imaging applications. The use of carbon nanotubes has been proved as contrasting agent in imaging. This work focuses on the latest developments in applications of carbon nanotubes for regenerative medicine. Carbon nonotubes have been under investigation in the past decade for an array of applications due to their unique and versatile properties. In the field of regenerative medicine, they have shown great promise to improve the properties of tissue engineering scaffolds and perform drug delivery and imaging of engineering tissues. The work is a review of the latest advances.