The last five years have witnessed a huge breakthrough in the creation and the study of the properties of a new class of compounds - metamaterials. The next stage of this technological revolution will be the development of active, controllable, and non-linear metamaterials, surpassing natural media as platforms for optical data processing and quantum information applications. However, scientists are constantly faced with the need to find new methods that can ensure the formation of quantum and non-linear metamaterials with higher resolution. One such method of producing metamaterials in the future, which will provide scalability and availability, is chemical synthesis. Meanwhile, the chemical synthesis of organized 3D structures with a period of a few nanometers and a size of up to a few millimeters is not an easy task and is yet to be resolved. The most promising avenue seems to be the use of highly porous structures based on metal-organic frameworks that have demonstrated their unique properties in the field of non-linear optics (NLO) over the past three years. Thus, the aim of this review is to examine current progress and the possibilities of using metal-organic frameworks in the field of non-linear optics as chemically obtained metamaterials of the future. The review begins by presenting the theoretical principles of physical phenomena represented by mathematical descriptions for clarity. Major attention is paid to the second harmonic generation (SHG) effect. In this section we compare inorganic single crystals, which are most commonly used to study the effect in question, to organic materials, which also possess the required properties. Based on these data, we present a rationale for the possibility of studying the non-linear optical properties of metal-organic structures as well as describing the use of synthetic approaches and the difficulties associated with them. The second part of the review explicitly acquaints the reader with a new class of materials which successfully combines the positive properties of organic and inorganic materials. Using recently synthesized metal-organic frameworks and coordination polymers in the field of non-linear optics as an example, we consider synthetic approaches used for obtaining materials with desired properties and the factors to be considered in this case. Finally, probable trends towards improving the quality of the synthesized materials with regards to their further use in the field of non-linear optical effects are described.

Mortality and disabilities as outcomes of cardiovascular diseases are primarily related to blood clotting. Optimization of thrombolytic drugs is aimed at the prevention of side effects (in particular, bleeding) associated with a disbalance between coagulation and anticoagulation caused by systemically administered agents. Minimally invasive and efficient approaches to deliver the thrombolytic agent to the site of clot formation are needed. Herein, we report a novel nanocomposite prepared by heparin-mediated cross-linking of urokinase with magnetite nanoparticles (MNPs@uPA). We showed that heparin within the composition evoked no inhibitory effects on urokinase activity. Importantly, the magneto-control further increased the thrombolytic efficacy of the composition. Using our nanocomposition, we demonstrated efficient lysis of experimental clots in vitro and in animal vessels followed by complete restoration of blood flow. No sustained toxicity or hemorrhagic complications were registered in rats and rabbits after single bolus i.v. injection of therapeutic doses of MNPs@uPA. We conclude that MNPs@uPA is a prototype of easy-to-prepare, inexpensive, biocompatible, and noninvasive thrombolytic nanomedicines potentially useful in the treatment of blood clotting.

Burn wounds are one of the most important causes of mortality and especially morbidity around the world. Burn wound healing and skin tissue regeneration remain thus one of the most important challenges facing the mankind. In the present study we have addressed this challenge, applying a solution-stabilized dispersion TiO 2 nanoparticles, hypothesizing that their ability to adsorb proteins will render them a strong capacity in inducing body fluid coagulation and create a protective hybrid material coating. The in vitro study of interaction between human blood and titania resulted at enhanced TiO 2 concentrations in formation of rather dense gel composite materials and even at lower content revealed specific adsorption pattern initiating the cascade response, promising to facilitate the regrowth of the skin. The subsequent in vivo study of the healing of burn wounds in rats demonstrated formation of a strongly adherent crust of a nanocomposite, preventing infection and inflammation with quicker reduction of wound area compared to untreated control. The most important result in applying the TiO 2 dispersion was the apparently improved regeneration of damaged tissues with appreciable decrease in scar formation and skin color anomalies.Accelerated and less painful healing of wounds caused by burn or mechanical injuries and skin and muscle tissue engineering for decreased scar formation and minimization of permanent damage belong to most prominent challenges in modern surgery 1 . Application of nanostructured materials for improved tissue regeneration has become a well-developed and accepted practice in the application of metal bone implants, where a thin layer of nanostructured titanium dioxide is deposited on the top of the implant surface 2,3 . Nano titania is rapidly getting coated with proteins when immersed into the biological fluids due to its well-recognized ability to adsorb and coordinate proteins 4 and phospholipids 5 on its surface. Adsorption of phospholipids can be considered as one of the factors guiding the attachment of cells and grafting on the growing tissue on an implant 6 . In the domain of skin regeneration a strong effort so far has been set on application of stem cells. They have been applied in different approaches, in particular, including sprays 7 . Use of nanomaterials for wound treatment and skin repair has also been intensively investigated ranging from silicone based artificial skin layers 8 , to the development of new materials for wound dressing with delayed and prolonged release of medicines 9,10 and even to direct application of nanoparticle dispersions either possessing themselves antibacterial effects, such as silver and gold nanoparticles 11-13 , or loaded with painkillers and antibiotics. The latter have been realized with metal oxide nanoparticles

Despite the fact that magnetic thrombolytic composites is an emerging area, all known so far systems are based on the similar mechanism of action: thrombolytic enzyme releases from the magnetic carrier leaving non-active matrix, thus making the whole system active only for a limited period of time. Such systems often have very complex structure organization and composition, consisting of materials not approved for parenteral injection, making them poor candidates for real clinical trials and implementation. Here we report, for the first time, the production of thrombolytic magnetic composite material with non-releasing behavior and prolonged action. Obtained composite shows good thrombolytic activity, consists of fully biocompatible materials and could be applied as infinitely active thrombolytic coatings or magnetically-targetable thrombolytic agents.

A fully biocompatible thrombolytic nanocolloid providing high stability and prolonged activity has been developed.

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The synthesis of new biocomposites exhibiting a synergistic effect is a promising step in the healing of acute and chronic wounds. In the present study we have combined four materials: chlorhexidine digluconate as a antimicrobial agent, lidocaine as a painkiller, chymotrypsin as a necrolytic agent, and sol-gel processed alumina as a carrier for the sustained delivery of drugs and as an established wound healer. Composites were synthesized and characterized for surface morphology, crystalline structure and in vitro drug release. In vivo wound healing efficacy was assessed using a full thickness excision wound model in Wistar rats. The main result, was that a marked decrease in scar size was observed because of the wound healing composite, in fact the area of the scar in the test group of rats was 2.4 times smaller than that in the control group. Wound closure analysis revealed that complete epithelialization was observed after 15 AE 1 days using the biocomposite, whereas this took 17 AE 1 days and 19 AE 1 days using the healing solution alone or pure alumina gel, respectively. It was concluded that the synergistic combination of healing drugs, with sol-gel alumina as dressing material, provides a highly attractive biomaterial for the treatment of surface wounds, burns and foot ulcers.

New nanocomposite material based on sol–gel magnetite for wound healing is described. Composition and drug release profile provides 1.5 fold acceleration wound healing rate and 2 fold lesser scar size.