This review is devoted to the medical application of silver nanoparticles produced as a result of “green” synthesis using various living organisms (bacteria, fungi, plants). The proposed mechanisms of AgNPs synthesis and the action mechanisms on target cells are highlighted.

Gold nanoparticles (AuNPs) are extremely promising objects for solving a wide range of biomedical problems. The gold nanoparticles production by biological method (“green synthesis”) is eco-friendly and allows minimization of the amount of harmful chemical and toxic byproducts. This review is devoted to the AuNPs biosynthesis peculiarities using various living organisms (bacteria, fungi, algae, and plants). The participation of various biomolecules in the AuNPs synthesis and the influence of size, shapes, and capping agents on the functionalities are described. The proposed action mechanisms on target cells are highlighted. The biological activities of “green” AuNPs (antimicrobial, anticancer, antiviral, etc.) and the possibilities of their further biomedical application are also discussed.

The data on the specifics of synthesis of elemental silver nanoparticles (Ag-NP) having various geometric shapes (pseudo spherical, prismatic, cubic, trigonal-pyramidal, etc.), obtained by using various biological methods, and their use in biology and medicine have been systematized and generalized. The review covers mainly publications published in the current 21st century. Bibliography: 262 references.

Biochemical properties of Bacillus intermedius subtilisin-like proteinase (AprBi) secreted by a B. subtilis recombinant strain in the early and late stationary phases of growth have been determined. Protein structure was analyzed and its stability estimated. It was noted that the enzyme corresponding to different phases of bacterial growth retains activity in the presence of reducing and oxidizing agents (C2H5OH and H2O2). Different effects of bivalent metal ions on activity of two proteinase fractions were found. Calcium ions more efficiently activate proteinase secreted in the late stationary phase. Unlike the first enzyme fraction, the second forms catalytically active dimers.

-Subtilisin-like proteinase Bacillus intermedius which is secreted at different stages of bacterial growth (at 28 h and 48 h) were purified from the culture media of recombinant strain Bacillus subtilis JB 20-36(pCS9) by chromatography on CM-cellulose and MonoS columns. MALDI-TOF mass spectroscopy of purified enzymes demonstrated that they were identical in regard to amino acid sequence. The molecular weights of both proteins were 27 kDa. Biochemical analysis revealed differences in K m values for proteinase isolated at different growth stages (1.85 and 0.86 mM for first and second fractions respectively), and in substrate specificity and sensitiveness to Ca 2+ ions. Gel-filtration experiments demonstrated that subtilisin-like proteinase B. intermedius was produced as an active monomer (27 kDa) during early stationary phase (28 h of growth) and as a dimer (54 kDa) during the late stationary phase (48 h).

The diverse biological properties of platinum nanoparticles (PtNPs) make them ideal for use in the development of new tools in therapy, diagnostics, and other biomedical purposes. “Green” PtNPs synthesis is of great interest as it is eco-friendly, less energy-consuming and minimizes the amount of toxic by-products. This review is devoted to the biosynthesis properties of platinum nanoparticles based on living organisms (bacteria, fungi, algae, and plants) use. The participation of various biological compounds in PtNPs synthesis is highlighted. The biological activities of “green” platinum nanoparticles (antimicrobial, anticancer, antioxidant, etc.), the proposed mechanisms of influence on target cells and the potential for their further biomedical application are discussed.

Two subtilisin-like serine proteinases of Bacillus intermedius secreted by the Bacillus subtilis recombinant strain AJ73 (pCS9) on the 28th and 48th h of culture growth (early and late proteinase, respectively) have been isolated by ion-exchange chromatography on CM-cellulose and by FPLC. Molecular weights of both proteinases were determined. The N-terminal sequences of the recombinant protein and mature proteinases of the original strain were compared. Kinetic parameters and substrate specificities of the early and late proteinase were analyzed. Physicochemical properties of the enzymes were studied.

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