High living standards and a comfortable modern way of life are related to an increased usage of various plastic products, yielding eventually the generation of an increased amount of plastic debris in the environment. A special concern is on microplastics (MPs), recently classified as contaminants of emerging concern (CECs). This review focuses on MPs’ adverse effects on the environment based on their bioactivity. Hence, the main topic covered is MPs’ ecotoxicity on various aquatic (micro)organisms such as bacteria, algae, daphnids, and fish. The cumulative toxic effects caused by MPs and adsorbed organic/inorganic pollutants are presented and critically discussed. Since MPs’ bioactivity, including ecotoxicity, is strongly influenced by their properties (e.g., types, size, shapes), the most common classification of MPs types present in freshwater are provided, along with their main characteristics. The review includes also the sources of MPs discharge in the environment and the currently available characterization methods for monitoring MPs, including identification and quantification, to obtain a broader insight into the complex problem caused by the presence of MPs in the environment.

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Nanocomposite structure of the bone can be mimicked by chitosan/hydroxyapatite (CS/HAp) composite scaffold. Biological hydroxyapatite (HAp) contains various ions, which have a crucial role in bone growth. The aim of the present work was to synthesize biomimetic hydroxyapatite and prepare composite scaffolds based on chitosan, where HAp was synthesised from hen eggshells, seashells and cuttlefish bone. The powders were composed of nano-structured calcium deficient HAp and amorphous calcium phosphate (ACP). In the as-prepared powders, Sr2+, Mg2+ and Na+ ions were detected as a result of using biogenic precursor of Ca2+ ions. Highly porous CS/HAp structures have been prepared by freeze-gelation technique. The CS/HAp scaffolds have shown highly porous structure with very well interconnected pores and homogeneously dispersed HAp particles. The MTT assay of CS/HAp scaffolds has shown no toxicity, and the live/dead assay has confirmed good viability and proliferation of seeded cells.

Biomimetic triphasic strontium‐substituted calcium phosphate (CaP) powders were prepared by wet precipitation method at 50°C, using CaCO3, (NH2)2COH3PO4, and Sr(NO3)2 as reagents. Calcite was prepared from biogenic source (cuttlefish bone). The synthesized powders have been characterized by elemental analysis, Fourier transform infrared spectrometry, X‐ray diffraction, Rietveld refinement studies and cell viability test. Phase transformation and ion release were analyzed during 7 days of incubation in simulated body fluid at 37°C. The raw precipitated powders were composed of calcium deficient carbonated hydroxyapatite (HA), octacalcium phosphate (OCP), and amorphous calcium phosphate (ACP). After heat treatment at 1200°C β‐tricalcium phosphate (β‐TCP) was detected. Strontium substitution for calcium results in an increase of lattice parameters in HA, OCP, and β‐TCP. Sr2+ occupy the Ca(1) site in HA, Ca(3,4,7,8) sites in OCP and Ca(1,2,3,4) sites in β‐TCP. Along with Sr2+ substitution, presence of Mg2+ and Na+ ions was detected as a result of using biogenic calcium carbonate. The culture of human embryonic kidney cells indicated noncytotoxicity of the prepared CaP powders with emphasis on the cell proliferation during 3 days of culture.