Inspired by nature, we explore biomolecules and their derivatives as novel biomedical and technological tools. nspired by nature, we explore biomolecules and their derivatives as novel biomedical and technological tools. Among biomolecules, proteins stand out as versatile biopolymers due to their high structural and functional adaptability, biocompatibility, and biodegradability. In particular, we mainly focus on a class of engineered repeat proteins, due to their stability and robustness as a base scaffold that can be easily tailored to endow desired functions to the protein and to encode defined supramolecular assembly properties. On the one hand, we have developed strategies to create ordered protein-based biomaterials by re-engineering protein-protein interactions.[1] On the other hand, the introduction of metal-binding residues (e.g., histidines, cysteines) drives the coordination of metal ions and the subsequent formation of tailored nanomaterials.[2] Additionally, new binding capabilities can be encoded within the CTPR unit or this can be conjugated with other peptides/proteins.[3] These properties allow the development of biopolymer-nanomaterial composites.[3,4] Generally, the fusion of two distinct materials exploits the best properties of each, however, in protein-nanomaterial composites, the fusion takes on a new dimension as new properties arise.
These composites have ushered the use of protein-based nanomaterials as biopharmaceuticals beyond their original therapeutic scope and paved the way for their use as theranostic agents, as demonstrated in our pioneering in vitro and in vivo examples.[4] In addition, these protein hybrids can be also implemented in technological applications, towards protein-based bioelectronic materials. [5]

Polymeric materials based on smart or intelligent polymers are designed to undergo reversible and controllable changes in their physical and chemical properties as response to small changes in environmental conditions such as, pH, temperature, electric and magnetic fields, ions, light intensity or enzymes, thus finding applications in biomedical field or in environmental remediation [1,2]. In this research, a smart graft copolymer based on temperature-responsive polymer [poly(N-isopropylacrylamide), PNIPAM] and a pH-responsive polysaccharide was prepared using a two-stages process. The first stage involves the synthesis of PNIPAM via reversible addition-fragmentation chain transfer polymerization in presence of a suitable chain transfer agent, achieving good control over the molecular mass and polydispersity index of polymer [3]. The second stage consists in grafting of PNIPAM onto polysaccharide backbone via grafting-to approach. ATR-FTIR and 1H NMR methods confirm the structure of the grafted copolymer. The degree of substitution of the graft copolymer was determined using 1H NMR spectroscopy and according to the calculations it was found that the grafting density is about one PNIPAM chain at every 24 polysaccharide monomeric units. Self-assembly capacity of the graft copolymers in aqueous media was investigated by dynamic light scattering. The thermal decomposition of graft copolymers took place in two clear steps, which correspond to the individual degradation step of each component, providing additional arguments that PNIPAM was successfully grafted on polysaccharide.

Acknowledgements: This work was funded by the Ministry of Research, Innovation and Digitization, with project number PNRR-III-C9-2022-18-201, within the National Recovery and Resilience Plan.

Collagen, a natural protein, exhibits strong piezoelectric properties due to dipole alignment within its triple helix structure. However, its poor structural stability limits its practical integration into high-performance, eco-friendly piezoelectric devices. Inspired by collagen’s hierarchical organization, biomimetic materials based on synthetic polypeptides with α-helix structures are expected to achieve strong electromechanical coupling, thereby enabling technologically relevant piezoelectricity. A key challenge in this approach is the realization of macroscopic dipole alignment, which could be addressed by employing block copolymer (BCP) self-assembly in thin films to direct molecular orientation and generate periodic nanoscale patterns, thereby enhancing piezoelectric performance.

In this work, synthetic polypeptides were prepared via ring-opening polymerization of N-carboxyanhydrides (NCAs) derived from amino acids. The introduction of chiral centers and side chains promoted the formation of α-helical structures with aligned dipoles. To induce mesoscale alignment of these α-helical structures, the synthetic polypeptides were combined with a second coil block, forming hierarchical structures with controlled nanometer-scale periodicities. We investigated the self-assembly behavior of these hybrid BCPs in thin films, tuning the BCP composition, overall molecular weight and self-assembly conditions to promote the formation of well-organized BCP patterns. Dielectric spectroscopy was further employed to correlate the macromolecular characteristics of the self-assembled polypeptide-based BCPs with their dielectric device properties.

This study demonstrates that integrating synthetic polypeptides with self-assembly strategies enables the design of biomimetic piezoelectric materials, opening avenues for biodegradable and biocompatible piezoelectric systems, particularly in biomedical applications.

Interpolyelectrolyte complexes (IPECs) formed between synthetic polymers and enzymes represent a promising approach to developing innovative biocatalysts for different applications [1]. The embedment of enzymes in such structures preserves the enzymatic activity in various process conditions, increasing the stability of the enzyme, and facilitating the biocatalyst's recovery and its reuse in multiple reaction cycles [2]. This study presents a comprehensive analysis of the formation of IPECs between poly(ethyleneimine) (PEI), poly(sodium methacrylate) (PMANa) and catalase (CAT) in bi-component (PEI/PMANa and PMANa/CAT) and tri-component systems (PEI/PMANa/CAT). The self-assembly in bi-component systems was studied assessing the influence of the molar ratio, solutions pH, components order of addition and the presence of salt in the formation of IPECs. The interaction between components was systematically analysed by a combination of dynamic light scattering, UV-Vis spectroscopy, scanning-transmission electron microscopy and turbidity measurements, obtaining important information about the size and morphology of the formed IPECs. Following the conclusions from studying the interactions in bi-component systems, the formation of tri-component IPECs was further investigated in the optimized conditions. The results obtained in this study highlighted the primordial role of the polyelectrolyte complexes formation/stability for subsequent use, as for the design of new inorganic core/organic shell composites, where the active sites of the enzyme could be preserved and further used in the degradation of some organic contaminants (dyes, drugs, etc.) from surface waters.
Acknowledgements: This work was supported by a grant from the Ministry of Research, Innovation and Digitization, CNCS - UEFISCDI, project number PN-IV-P1-PCE-2023-1545, within PNCDI IV.

Shape-morphing hydrogels are hydrophilic polymer networks that deform upon swelling/deswelling in aqueous media[1]. Such materials are promising for biomedical applications[2], but combining biocompatibility, biodegradability, and programmable deformation in hydrogel systems remains challenging.
In this context, we aim to design composite shape-morphing hydrogels using a biocompatible and biodegradable polymer matrix with a controlled deformation guided by the orientation of embedded rigid fibers.
To this end, microfibers of Calcium phosphate (CaP), a primary component of bone mineral, were first synthesized and rendered magnetically responsive by a surface coating of iron oxide nanoparticles (IONPs) (Fig. A). Secondly, Hyaluronic Acid (HA), a ubiquitous polysaccharide in the human body, was functionalized with methacrylate (MA) groups[3] to formulate highly swellable photocrosslinked hydrogels (Fig. B). Subsequently, the magnetic alignment of the fibers within the hydrogel was studied. Fiber alignment kinetics were investigated and compared to theoretical models, while the influence of key physicochemical parameters (polymer viscosity, fiber size, and magnetic field strength) were evaluated. Optimal conditions for efficient fiber alignment were identified (Fig. C-i), enabling the creation of an anisotropic microstructure that yielded the directional swelling behavior of the hydrogel (Fig. C-ii). Finally, by exploiting this anisotropic swelling, hydrogel architectures displaying different degrees and different types of programmed deformation (bending, twisting) were designed (Fig. D).
Current work is therefore focused on exploring the potential of this material as a biological scaffold for cells.

Bio-based and biodegradable polymers are interesting materials able to positively contribute to the current environmental concerns in terms of the plastic pollution and greenhouse gas emissions.
Furandicarboxylate-based polyesters have emerged as new interesting bio-based polymers. All the furandicarboxylate-based polyesters exhibit better mechanical and gas barrier properties with respect to the homologous terephthalic-based polyesters [1]. Biodegradation of this family of polyesters can be improved by introducing aliphatic units in the chain, which however worsen the mechanical and barrier properties [2]. A technique useful to counterbalance this negative effect is the incorporation of nano-sized fillers to obtain nanocomposites.
This study has been focused on the preparation of bio-based and biodegradable nanocomposites of poly(butylene furandicarboxylate) (PBF) and PBF-based copolymers to produce materials with good mechanical, barrier and biodegradation properties.
The major challenges to develop nanocomposites for advanced technological applications is the capacity to understand the structure and properties of the interphase between the polymer and nanofillers.
The aim of the present study has been to investigate the role that the nano-sized interphases, at the amorphous/crystal and at the amorphous/filler boundaries, have on the mechanical and barrier properties of nanocomposites of PBF and PBF-based copolymers containing various nanofillers.

The work has been funded by European Union (NextGenerationEU) (PNRR - M4, C2, I1.1) through the PRIN 2022 PNRR project bio-FURther (P20227JXT8)