The thermal and solvent tolerance of enzymes is highly important for their industrial use. We show here that the enzyme lipase from Rhizopus oryzae exhibits exceptionally high thermal stability and high solvent tolerance and even increased activity in acetone when immobilized onto a graphene oxide (GO) nanosupport prepared by Staudenmaier and Brodie methods. We studied various forms of immobilization of the enzyme: by physical adsorption, covalent attachment, and additional crosslinking. The activity recovery was shown to be dependent on the support type, enzyme loading and immobilization procedure. Covalently immobilized lipase showed significantly better resistance to heat inactivation (the activity recovery was 65% at 70 °C) in comparison with the soluble counterpart (the activity recovery was 65% at 40 °C). Physically adsorbed lipase achieved over 100% of the initial activity in a series of organic solvents. These findings, showing enhanced thermal stability and solvent tolerance of graphene oxide immobilized enzyme, will have a profound impact on practical industrial scale uses of enzymes for the conversion of lipids into fuels.

We exploit the biodegradability of polylactic acid to sculpt 3D-printed surfaces at the micro- and nanoscale. Graphene/polylactic acid electrodes were activated by selective enzyme-guided cleavage of polylactic acid fragments at the surface.

Conventional drug delivery systems face several issues in medical applications, such as cyto/genotoxicity and off-targeting. These issues are particularly significant for cancer therapeutics because many of the currently used systems are toxic in their free form. Self-propelled autonomous micro/nanomachines offer promising alternative drug delivery systems based on high cargo loading, fast autonomous movement, precise targeting and the on-demand release of therapeutics in vivo. With this unique set of properties, it is not surprising that they are receiving considerable research attention. However, much less is reported about the drawbacks that hinder their systemic in vivo application. In this review, a biomedical perspective is used to assess micro/nanomotor-based anticancer drug delivery systems reported to date. Advantages along with present issues are highlighted and recommendations which need to be considered to develop an effective biocompatible micro/nanomotor-based delivery system for cancer therapy are discussed.

Anaerobic processes for the treatment of plastic materials waste represent versatile and effective approach in environmental protection and solid waste management. In this work, anaerobic biodegradability of model aliphatic polyesters, poly(L-lactic acid), PLA, and poly(ɛ-caprolactone), PCL, in the form of powder and melt-pressed films with varying molar mass was studied. Biogas production was explored in batch laboratory trials at 55 ± 1°C under the nitrogen atmosphere. The inoculum used was thermophilic digested sludge (TS concentration of 2.9%) from operating digesters at Central Waste Water Treatment Plant in Prague, Czech Republic. Methanogenic biodegradation of PCLs typically yielded from 54 to 60% of the theoretical biogas yield. The biodegradability of PLAs achieved from 56 to 84% of the theoretical value. High biogas yield (up to 677 mL/g TS) with high methane content (more than 60%), comparable to conventionally processed materials, confirmed the potential of polyesters samples for anaerobic treatment in the case of their exploitation in agriculture or as a packaging material in the food industry.

Aliphatic poly(ester-carbonates) are receiving extensive research attention as tailorable materials suitable for multiple applications from tissue engineering and 3D scaffold printing to drug delivery. Thus, simple reliable procedures for producing easily tailorable poly(ester-carbonates) without metal residues are continuously sought after. In this work, we report on one-pot synthesis of random copolymers of TMC and δ-VL using metal-free biocompatible 1,5,7-triazabicyclo[4.4.0]dec-5-ene as a catalyst and benzyl alcohol and poly(ethylene oxide) as initiators. Random poly(ester-carbonates) with TMC : VL unit ratios ranging from 80 : 20 to 20 : 80 were synthesized via ring-opening polymerization while displaying excellent agreement of comonomers' ratios in the feed and copolymer chains. The copolymers' supramolecular structure, thermal and mechanical properties were thoroughly analyzed by various methods. The obtained results clearly indicated that the physicochemical properties can be controlled simply by varying the ratio of comonomers and the length of segments in the copolymer chain. Several copolymers exhibited behavior of thermoplastic elastomers with the most promising one exhibiting a 2200% increase in elongation at break compared to the poly(valerolactone) homopolymer while retaining tensile strength and Young's modulus suitable for biomedical applications. Overall, our work contributed to widening the portfolio of tailorable copolymers for specialized bioapplications and possibly paving a way for the use of more sustainable polymers in the biomedical field.