Critical Reviews in Therapeutic Drug Carrier Systems最新文献

Natural polymers have received more attention because of their advantages over synthetic polymers such as abundant availability, low cost, biodegradability and non-toxicity. However, natural polymers suffer some limitations such as drop-in viscosity upon storage, uncontrolled hydration, solubility, inability to perform under high temperature and pressure (thermal stability), etc. In many instances above mentioned drawbacks of natural polymers limits their applications in drug delivery systems. Grafting of natural polymer leads to improved properties and characteristics of backbones of macromolecules such as improvement in gel strength, swelling index, mucoadhesion, drug targeting and drug release profile. Therefore, in recent decades grafting of the natural polymer has gained immense importance for the development of drug delivery systems. In addition to the pharmaceutical applications graft copolymers are extensively utilized in diversified fields. The present review is an attempt to define the grafting, various methods of polymer grafting and their application in drug delivery.

Captopril is an angiotensin-converting enzyme (ACE) inhibitor that prevents angiotensin I (ATI) from being converted to angiotensin II (ATII). However, it offers certain limitations like instability, dose dumping and burst release due to its usage in the native state. In the last two decades, different polymers and excipients have been used to make captopril more accessible and well-accepted. The present work discusses the efforts made by various scientists so far to make the oral administration of captopril more acceptable by overcoming its limitations. The different factors affecting gastric retention, approaches to achieve better gastric retention. The oral managed release dosage forms have enormous curative benefits such as improved therapeutics and better patient compliance. The polymer based gastro-retentive drug delivery systems (GRDDS) include microspheres, soild inclusion complex, floating tablets, alginate based beads, etc utilizes better retention in the stomach for longer duration of action and improved bioavailability. Overall, the work aims to summarize the attempts made as novel drug delivery approaches over the last two decades in reverse chronological order to make captopril more gastro retentive and orally acceptable by the patients.

This article aims to provide a comprehensive review of Cissus quadrangularis (CQ), which is a traditional medicinal herb and has a potential osteoprotective effect. CQ is a perennial climber of family Vitaceae that is commonly found in the hotter parts of India. It is most widely used in India for improving bone health and is well known as "hadjod." It shows an anti-osteoporotic effect through different pathways mechanisms. It is natural matrices of excellence with proven bioactivity. Several cell line and animal studies demonstrated its protective nature against many diseases such as osteoporosis, arthritis, gastric ulcers etc. This review also highlights the phytochemicals identified to the date and related pharmacological applications. The discussion has also expanded to its oral formulations, which has been proven for its efficacy practically. However, the scientific information of CQ is not in the proper documentation for reference, and so availability of scientific knowledge of this climber is limited. Therefore, this review might be provided a platform to those who will be interested in studying further this herb, either for analyzing phytochemical profiling or its anti-osteoporotic usage. This is a crucial platform as several productive results have been reported on this herb, which likely to be beneficial for new drug discovery in future. Here we also discuss the bone remodeling and related factors influenced by the intake of CQ.

Brain tumors pose a serious burden to health care because the cancers are usually incurable, despite advancements in treatment strategies including surgery, radiotherapy, and chemotherapy. Most studies report that specific drugs are effective in vitro, but many lose their therapeutic value in clinical settings. Maintaining therapeutic drug concentrations as an agent reaches a cancer target is the efficacy prerequisite for any form of treatment. However, in the case of brain tumors, the blood-brain barrier (BBB) acts to physically and physiologically block the drug, which complicates treatment options. In addition, strategies are limited by a number of factors such as difficulties that are associated with targeting tumor cells. The therapeutic potential of targeted drug delivery as an alternative to current strategies is gaining significant ground, with many studies highlighting its efficacy and compatibility in overcoming the BBB before reaching its final target in brain. In this review, we briefly describe basic physiology associated with the BBB and how modern science is taking advantage of physiological processes to deliver anticancer agents to brain. We also summarize different modes of drug delivery and highlight how nanoparticles as drug-delivery vehicles are used for drug transport in brain tumors as well as different types of surface modification that are used to increase target potential.

Exosomes are endogenous extracellular vesicles (30-100 nm) composed with membrane lipid bilayer which carry vesicular proteins, enzymes, mRNA, miRNA and nucleic acids. They act as messengers for intra- and inter-cellular communication. In addition to their physiological roles, exosomes have the potential to encapsulate and deliver small chemotherapeutic drugs and biological molecules such as proteins and nucleic acid-based drugs to the recipient tissue or organs. Due to their biological properties, exosomes have better organotropism, homing capacity, cellular uptake and cargo release ability than other synthetic nano-drug carriers such as liposomes, micelles and nanogels. The secretion of tumor-derived exosomes is increased in the hypoxic and acidic tumor microenvironment, which can be used as a target for nontoxic and nonimmunogenic drug delivery vehicles for various cancers. Moreover, exosomes have the potential to carry both hydrophilic and hydrophobic chemotherapeutic drugs, bypass RES effect and bypass BBB. Exosomes can be isolated from other types of EVs and cell debris based on their size, density and specific surface proteins through ultracentrifugation, density gradient separation, precipitation, immunoaffinity interaction and gel filtration. Drugs can be loaded into exosomes at the biogenesis stage or with the isolated exosomes by incubation, electroporation, extrusion or sonication methods. Finally, exosomal cargo vehicles can be characterized by ultrastructural microscopic analysis. In this review we intend to summarize the inception, structure and function of the exosomes, role of exosomes in immunological regulation and cancer, methods of isolation and characterization of exosomes and products under clinical trials. This review will provide an inclusive insight of exosomes in drug delivery.

Oral cancer is the 11th most common cancer in the world with a high morbidity rate. Various conventional therapies have been used for the treatment of oral cancer such as surgery, radiotherapy, and chemotherapy used either alone or in combination but these have many limitations, making them unsuitable for treating oral cancer. Nanotechnology has been emerged out as an innovative tool in the field of oral cancer which has proved to provide effective results overcoming the limitations of conventional drug therapies. This system involves a nanoparticle drug delivery system based on a targeted therapy in which therapeutic drugs or agents act on the targeted cells without affecting normal healthy cells. Literature has shown that several nanoparticles, organic and inorganic nanoparticles, have been used as the drug delivery system in different types of oral cancers such as oral squamous cell carcinoma, cancer of the tongue, head, and neck cancers. Drugs like cisplatin, 5-fluorouracil, methotrexate, doxorubicin, etc., when coated with nano-polymers have shown better results compared with conventional drugs in oral cancer. Other nanoparticles such as liposomes, hydrogels, nanodiamonds, carbon rods, etc. have also been used with minimal side effects. This paper aims to review and discuss various nanotechnology systems in the field of oral cancer and to evaluate the efficacy of these systems in treating oral cancer compared with conventional drug delivery methods.

Viral infections such as AIDS, hepatitis, herpes keratitis, and herpes labialis became resistant to drugs and it is difficult to design vaccine. In current era drug-resistant viruses are now treated by nanoparticles (NPs) and this field is known as nanobiotechnology that relates nanoscience with the biological system. NPs due to their antiviral activity are used in the treatment of viral diseases. The advantages of using the NP is its specific target action and increase the efficiency of treatment with minimum side effects. Liposomes, quantum dots, polymeric NPs, solid lipid NPs, silver NPs, gold NPs, and magnetic NPs are used to treat viral infections. NP-based therapeutics have completely replaced the usage of drugs and vaccines for viral diseases treatment. Nano vaccines have been investigated for the delivery of drugs; biomaterials-based NPs are in development to be formulated into nano vaccines. But there are limitations in the manufacturing and stabilization of NPs in the body. This review focuses on the antiviral activity of several NPs, its uptake by different viruses for viral disease treatment, nano vaccines, and the limitation of the NPs as nanotherapeutics.

Applications of nanoceria in the biomedical field are quite promising, as previous data has shown potential use of nanoceria as therapeutics via radical scavenging and oxidative stress mitigating properties. But, still, there are contradicting reports regarding nanoceria activity, mode of action, and in vitro toxicity in the cell. There are different nanoceria synthesis methods and Ligands for functionalization and loading of nanoceria into drugs for targeted drug delivery. Redox chemistry of nanoceria exerts their anticancer properties through apoptosis and oxidative stress as it can switch between Ce3+ and Ce4+ and act as free radical scavengers. For breast cancer treatment, cerium oxide nanoparticles (CeONPs) can act as protectant for healthy cells against on-going radiotherapy. Similarly, CeONPs were used to make pancreatic cancer cells more sensitive to radiation damage setting them on the apoptotic pathway. Herein, the study reflects the use of nanoceria as a drug delivery system in chemotherapy due to its efficiency in acidic pH and oxidase activity in the microenvironment. A controlled drug delivery system was adapted using a nano-complexes of AMD-GCCNP-DOX, which were then employed against the retinoblastoma cells from the human eye to target the overexpressing chemokine receptor 4 (CXCR4). In radiotherapy, nanoceria acts as radioprotectants due to their free radical scavenging property and inhibit the proliferation and migration of gastric cancer. This paper summarizes the synthesis methods and application of nanoceria in cancer.