Insights on the bioremediation technologies for pesticide-contaminated soils.

The fast pace of increasing human population has led to enhanced crop production, due to which a significant increase in the application of pesticides has been recorded worldwide. Following the enhancement in the utilization of pesticides, the degree of environmental pollution, particularly soil pollution, has increased. To address this challenge, different methods of controlling and eliminating such contaminants have been proposed. Various methods have been reported to eradicate or reduce the degree of contamination of pesticides in the soil. Several factors are crucial for soil contamination, including pH, temperature, the number, and type/nature of soil microorganisms. Among the accessible techniques, some of them respond better to contamination removal. One of these methods is bioremediation, and it is one of the ideal solutions for pollution reduction. In this innovative technique, microorganisms are utilized to decompose environmental pollutants or to curb pollution. This paper gives detailed insight into various strategies used for the reduction and removal of soil pollution.

Avian Egg: A Multifaceted Biomaterial for Tissue Engineering.

Most components in avian eggs, offering a natural and environmentally friendly source of raw materials, hold great potential in tissue engineering. An avian egg consists of several beneficial elements: the protective eggshell, the eggshell membrane, the egg white (albumen), and the egg yolk (vitellus). The eggshell is mostly composed of calcium carbonate and has intrinsic biological properties that stimulate bone repair. It is a suitable precursor for the synthesis of hydroxyapatite and calcium phosphate, which are particularly relevant for bone tissue engineering. The eggshell membrane is a thin protein-based layer with a fibrous structure and is constituted of several valuable biopolymers, such as collagen and hyaluronic acid, that are also found in the human extracellular matrix. As a result, the eggshell membrane has found several applications in skin tissue repair and regeneration. The egg white is a protein-rich material that is under investigation for the design of functional protein-based hydrogel scaffolds. The egg yolk, mostly composed of lipids but also diverse essential nutrients (e.g., proteins, minerals, vitamins), has potential applications in wound healing and bone tissue engineering. This review summarizes the advantages and status of each egg component in tissue engineering and regenerative medicine, but also covers their current limitations and future perspectives.

Heavy-metal contamination and solid-phase fractionation in street dust.

Fourteen street-dust samples were collected from Hamedan, western Iran. Street-dust samples received different amounts of heavy-metal pollution. The samples were analyzed for total cadmium (Cd), copper (Cu), lead (Pb), nickel (Ni), and zinc (Zn), and binding forms of heavy metal were determined in five fractions. The results showed Cd was the only metal present appreciably, 25.21% and 25.92%, in the exchangeable and carbonates fractions, respectively, and Cu was the only metal predominantly associated, 31.77%, with organic fraction. Zn, 45.84%, was present mainly in the Fe-Mn oxide fraction, and the residual fraction was the most dominant solid phase pool of Ni and Pb, respectively, with 42.56% and 41.31%. The order of apparent mobility and potential metal bioavailability for these contaminated street-dust samples is Cd > Zn > Cu > Pb > Ni. The risk-assessment code results showed very high risk for Cd; medium risk for Cu, Pb, and Zn; and low risk for Ni.