Silver nanoparticles: synthesis, characterisation and biomedical applications

Nanotechnology is a rapidly growing field due to its unique functionality and a wide range of applications. Nanomedicine explores the possibilities of applying the knowledge and tools of nanotechnology for the prevention, treatment, diagnosis and control of disease. In this regard, silver nanoparticles with diameters ranging from 1 to 100 nm are considered most important due to their unique properties, ability to form diverse nanostructures, their extraordinary range of bactericidal and anticancer properties, wound healing and other therapeutic abilities and their cost-effectiveness in production. The current paper reviews various types of physical, chemical and biological methods used in the production of silver nanoparticles. It also describes approaches employing silver nanoparticles as antimicrobial and antibiofilm agents, as antitumour agents, in dentistry and dental implants, as promoters of bone healing, in cardiovascular implants and as promoters of wound healing. The paper also explores the mechanism of action, synthesis methods and morphological characterisation of silver nanoparticles to examine their role in medical treatments and disease management.

Adverse reactions during chemotherapy: skin toxicity

Chemotherapy of oncological diseases is associated with high toxicity. The occurrence of various toxic reactions during the use of antitumor drugs is explained by the fact that most antitumor medicines are not strictly specific, therefore, their effect can extend not only to tumor cells, but also to normal cells, especially to tissues with rapid proliferation. All antitumour agents have skin toxicity in one form or another. However, for some chemotherapeutic agents, skin toxicity is a kind of «reflection» of certain mechanisms of drugs action, and, in most cases, the severity of dermatological reactions correlates with the effectiveness of chemotherapy. Dermatological toxicity deserves special attention, as it affects the quality of life of cancer patients and, in some cases, may require a dose reduction or even cancellation of chemotherapy. This article presents current data on the mechanisms of development of skin toxicity of routine chemotherapeutic agents, growth factor inhibitors and some antitumor antibiotics, its correction and prevention opportunities.

Medicinal Properties of Flavonoids: الفلافونويدات وخواصها الدوائية

Flavonoids are ubiquitous in photosynthesizing cells and are commonly found in fruit, vegetables, nuts, seeds, stems, flowers, tea, and honey. Therefore, a significant quantity is consumed in our daily diet. These flavonoids are variously associated with the sensory and nutritional quality of our plant foods. For centuries, preparations containing these compounds as the principal physiologically active constituents have been used to treat human diseases. There has been increasing interest in the research on flavonoids from plant sources because of their versatile health benefits reported in various epidemiological studies. Since flavonoids are directly associated with human dietary ingredients and health, there is need to evaluate structure and function relationship. There have been many bioassay guided searches for cytotoxic antitumour agents in plants especially those known to be used in folk medicine for this purpose. This has led to the isolation and identification of quite a large number of active constituents from all the different flavonoid classes, e.g. catechins, flavans, dihydrochalcones, chalcones, flavanones, dihydro-flavonols, flavones, biflavonoids and flavonol. The purpose of the present review is to discuss recent developments in the biochemistry and medicinal aspects of the flavonoids. Flavonoids have received a lot of interest in scientific research over the past 20 years and have had many beneficial and potential effects. Flavonoids have many great advantages as natural compounds compared to therapeutic agents because many diets are rich in polyphenols and are consumed daily and are easily absorbed in the intestines after ingestion, especially flavonoids, have positive effects on health: antioxidants, lethargy, allergies and bacteria, And cancer. The protective effect of flavonoids is primarily due to its antioxidant effect and inhibition of enzymes. The protective effect of flavonoids from diseases is mainly due to their antioxidant effect. Recent research on the biological properties of flavonoids will therefore be a further subject of the present review.

HUMANIZED MICE: CREATION, MODELS AND USE IN EXPERIMENTAL ONCOLOGY (REVIEW)

Research laboratories in various countries are constantly endeavouring to improve the existing and to create new biological objects to simulate various human diseases. Immunodefi cient mice with transplanted human functional cells and tissues, as well as transgenic animals with the relevant human genes integrated in their genome — i. e. humanized mice — are increasingly used as test systems in biomedical studies. Humanized mouse models are constantly being improved to fi nd application in studies investigating human biological reactions and identifying the pathogenetic mechanisms behind a wide range of diseases, or as preclinical tools for medicine testing. In particular, such animals play an increasingly important role both in studies of human-specifi c infectious agents, cancer biology research and in the development of new antitumour agents. In addition, humanized mice are increasingly used as translational models in many areas of clinical research, including transplantology, immunology and oncology. Ultimately, the use of humanized animals can lead to the introduction of a truly personalized medicine into clinical practice. In this review, we discuss modern advances in the creation and use of humanized mice, emphasizing their usefulness for the pathogenesis study, as well as the development of new methods for human cancer treatment.

Antitumor Activities of Flavonoids and Their Biological Activities on Human Health: الفلافونويدات المضادة للأورام ونشاطاتها البيولوجية على صحة الإنسان

Flavonoids are ubiquitous in photosynthesising cells and are commonly found in fruit, vegetables, nuts, seeds, stems, flowers, tea, wine, propolis and honey. Therefore, a significant quantity is consumed in our daily diet. These flavonoids are variously associated with the sensory and nutritional quality of our plant foods. For centuries, preparations containing these compounds as the principal physiologically active constituents have been used to treat human diseases. There have been many bioassay guided searches for cytotoxic antitumour agents in plants especially those known to be used in folk medicine for this purpose. This has led to the isolation and identification of quite a large number of active constituents from all the diferent flavonoid classes, e.g. catechins, flavans, dihydrochalcones, chalcones, flavanones, dihydro- flavonols, flavones, biflavonoids and flavonol. The purpose of the present review is to discuss recent developments in the biochemistry and medicinal aspects of the flavonoids. It is already well established that flavonoids make some contribution to disease resistance. Perhaps the most active area of flavonoid research at the present time is in the possible medicinal contribution that flavonoids make to human health, It is well known that some flavonoids can act as anti-spasmolytic agents, antibacterial activity, hepatoprotective agents and prevention of malaria. Recent research on the biological properties of flavonoids will therefore be a further subject of the present review. The activity of 17- β- estradiol, for example, have a pharmacologicalefficacy, at optimal concentrations, which is equivalent to the natural hormone. The compounds: 4´,7´´- di- O- methylamentofavone and 7´´- O- methylrobustafavone, were significantly cytotoxic against human cell lines including breast, lung, colon and prostate cancer, fibrosarcoma, glibostoma, oral epidermoid carcinoma and leukemia. Amongst the favonols, quercetagetin 6,7,3´ ,4´- tetramethyl ether, was found to show significant cytotoxicity against murine leukaemia, human non- small cell lung cancer, human colon cancer, and KB tumour cells.