UV-dependent freshwater effect factor of nanoscale titanium dioxide for future life cycle assessment application.

Environmental impacts of nanoscale titanium dioxide (TiO2 ) should be assessed throughout the lifetime of nanoparticles (NPs) to improve the state of knowledge of the overall sustainability. Life cycle assessment (LCA) has been previously recognized as a promising approach to systematically evaluating environmental impacts of NPs. As a result of their unique nanospecific properties, characterization factors (CF) were previously used for compensating the release and potential impacts of TiO2 NPs. However, because TiO2 NPs are known to generate reactive oxygen species and elicit toxicity to freshwater organisms, the lack of adequate UV-dependent effect factors (EFs) remains a major shortcoming when addressing their life cycle impacts. To complement the LCA of TiO2 -NPs-enabled products under their specific applications, we recapitulated the freshwater toxicity of TiO2 NPs and then modeled in USEtox to determine trophic level EF ranges under UV and non-UV exposure conditions. Results indicate that EFs derived for non-UV exposure were 52 (42.9-65) potentially affected fraction (PAF) m3 /kg, and combined toxicity data derived EFs were 70.1 (55.6-90.5) PAF m3 /kg. When considering only the UV-induced exposure condition, the modeled EF increased to 500 (333-712) PAF m3 /kg. Our work highlights that case-dependent EFs should be considered and applied to reflect more realistic ecological impacts and illustrate comprehensive life cycle environmental impacts for nanoenabled products. Integr Environ Assess Manag 2023;19:578-585. © 2022 SETAC.

Industrially Relevant Enzyme Cascades for Drug Synthesis and Their Ecological Assessment.

Environmentally friendly and sustainable processes for the production of active pharmaceutical ingredients (APIs) gain increasing attention. Biocatalytic synthesis routes with enzyme cascades support many stated green production principles, for example, the reduced need for solvents or the biodegradability of enzymes. Multi-enzyme reactions have even more advantages such as the shift of the equilibrium towards the product side, no intermediate isolation, and the synthesis of complex molecules in one reaction pot. Despite the intriguing benefits, only a few enzyme cascades have been applied in the pharmaceutical industry so far. However, several new enzyme cascades are currently being developed in research that could be of great importance to the pharmaceutical industry. Here, we present multi-enzymatic reactions for API synthesis that are close to an industrial application. Their performances are comparable or exceed their chemical counterparts. A few enzyme cascades that are still in development are also introduced in this review. Economic and ecological considerations are made for some example cascades to assess their environmental friendliness and applicability.

A critical analysis of environmental sustainability metrics applied to green synthesis of nanomaterials and the assessment of environmental risks associated with the nanotechnology.

Nanotechnology is one of the most relevant scientific areas today due to its multiple applications in fields such as medicine, environmental remediation, information technology and energy conversion. This importance has led to the need to advance in the development of environmentally sustainable and safe nanomaterials by incorporating the principles of green chemistry during their synthesis and in their applications. However, this qualitative framework of thought does not offer minimum criteria for the use of the term "green", and therefore, this adjective is commonly used to refer to bio-based or nanotechnological processes without taking into account their net ecological impact. In this context, environmental sustainability metrics can be applied to nanotechnology to compare, optimize and quantify the environmental sustainability of synthesis procedures. This review provides an overview of green chemistry and its application in nanotechnology, but also an analysis of the use of green chemistry principles in the development of bio-based nanobiotechnology and nanosynthesis, with special emphasis on the use of sustainability's metrics for the quantitative analysis of nanomaterial synthesis protocols. These include: Atom Economy, E-factor, Process Mass Intensity, Energy Intensity, and Life Cycle Analysis.

Environmental Assessment of Enzyme Production and Purification.

The importance of bioprocesses has increased in recent decades, as they are considered to be more sustainable than chemical processes in many cases. E factors can be used to assess the sustainability of processes. However, it is noticeable that the contribution of enzyme synthesis and purification is mostly neglected. We, therefore, determined the E factors for the production and purification of 10 g enzymes. The calculated complete E factor including required waste and water is 37,835 gwaste·genzyme-1. This result demonstrates that the contribution of enzyme production and purification should not be neglected for sustainability assessment of bioprocesses.