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Tailoring surface properties by layer-by-layer (LBL) deposition directed on the construction of complex multilayer coatings with nanoscale precision enables the development of novel structures and devices with desired functional properties (i.e., osseointegration, bactericidal activity, biocorrosion protection). Herein, electrostatic self-assembly was applied to fabricate biopolymer-based coatings involving chitosan (CSM) and alginate (AL) enriched with caffeic acid (CA) on Ti-6Al-7Nb alloyed surfaces. The method of CA grafting onto the chitosan backbone (CA-g-CSM) as well as all used reagents for implant functionalization were chosen as green and sustainable approach. The final procedure of surface modification of the Ti-6Al-7Nb alloy consists of three steps: (i) chemical treatment in Piranha solution, (ii) plasma chemical-activation of the Ti alloy surface in a RF CVD (Radio Frequency Chemical Vapour Deposition) reactor using Ar, O2 and NH3 gaseous precursors, and (iii) a multi-step deposition of bio-functional coatings via dip-coating method. Corrosion tests have revealed that the resulting chitosan-based coatings, also these involving CA, block the specimen surface and hinder corrosion of titanium alloy. Furthermore, the antioxidant layers are characterized by beneficial level of roughness (Ra up ca. 350 nm) and moderate hydrophilicity (59°) with the dispersion part of conducive surface energy ca. 30 mJ/m2. Noteworthy, all coatings are biocompatible as the intact morphology of cultured eukaryotic cells ensured proper growth and proliferation, while exhibit bacteriostatic character, particularly in contact with Gram-(−) bacteria (E. coli). The study indicates that the applied simple sustainable strategy has contributed significantly to obtaining homogeneous, stable, and biocompatible while antibacterial biopolymer-based coatings.

An eco-friendly, efficient, and controlled synthesis of gold nanoparticles with application of the aqueous extract of Rosa damascena (Au@RD NPs) without using any other reducing agents was studied. Au@RD NPs of narrow size distribution were characterized by UV–vis and FT-IR spectroscopies, transmission electron microscopy, X-ray powder diffraction, X-ray photoelectron spectroscopy, particle size analysis, and zeta potential measurements. In vitro stability experiments revealed that the Au@RD NPs were stable for over a year (pH ~ 3.5), proving a significant stabilizing potential of the aqueous RD extract. The high total content of polyphenols, flavonoids, and reducing sugars along with the powerful antioxidant activity of the RD extract was determined by spectroscopic and analytical methods. Colloids prepared from the purified and lyophilized Au@RD NPs (electrokinetic potential of ca. -33 mV) were stable for at least 24 h under terms similar to physiological conditions (pH = 7.4, PBS). The in vitro cytotoxicity of Au@RD NPs was investigated against peripheral blood mononuclear lymphocytes (PBML), acute promyelocytic leukemia (HL60), and human lung adenocarcinoma (A549). Selective cytotoxicity of Au@RD NPs towards cancer cells (HL60, A549) over normal cells (PBML) in vitro was explicitly demonstrated by viability assays. Comet assay revealed a higher level of DNA damages in cancer cells when compared with normal ones. Apoptotic death in cancer cells was proved by measuring caspases activity. Thus, the developed Au@RD NPs, obtained by the plant-mediated green synthesis, are attractive hybrid materials for the medical applications combining two active components – metal nanoparticles platform and plant-derived metabolites.

Novel half-sandwich iridium(III) complexes with aminomethyl(diphenyl)phosphine derived from fluoroloquinolones (IrPCp, IrPSf, IrPLm, IrPNr) were studied as possible anticancer chemotherapeutics and showed higher potency than other well-known metal-based agents i.e., Pt(II) drugs. All compounds were characterized by elemental analysis, selected spectroscopic methods (i.e., absorption and fluorescence spectroscopy, NMR), ESI-MS spectrometry, X-ray diffraction, and electrochemical techniques. The studied complexes exhibited promising cytotoxicity in vitro with IC50 values significantly lower than that of the reference drug – cisplatin. The insight into the mode of action revealed the uniform distribution of the Ir(III) complexes in both the nucleus and cytoplasm (Pearson's co-localization coefficient of 0.63). Precise cytometric analysis provided clear evidence for the predominance of apoptosis in the induced cell death. The activation of caspase-3/7 along with the decrease of mitochondrial membrane potential also confirmed the apoptotic cell death. The investigated Ir(III) complexes may induce changes in the cell cycle leading to G2/M phase arrest. ROS generation as a plausible pathway responsible for the cytotoxicity was confirmed by determination of redox potentials enabling efficient ROS production. Furthermore, Pluronic P-123 micelles loaded with selected Ir(III) complexes were proposed to overcome low solubility and to minimize serious systemic side effects by administering the complex in a controlled manner. The resulting nanoformulations (IrPCp_M, IrPNr_M) facilitated efficient drug accumulation for human lung adenocarcinoma and human prostate carcinoma (A549 and DU-145 cell lines), as demonstrated by confocal microscopy and ICP-MS analysis. In vitro cytotoxicity assays were also carried out within multicellular tumor spheroids and efficient anticancer action on these 3D assemblies was demonstrated.