With the transition towards more sustainable paints formulations based on waterborne environment, their susceptibility for microbial contamination has to be better controlled in order to increase shelf life and functional lifetime. However, recent restrictions in European regulation on use of biocides have put limitations on the possibilities for traditional systems providing either in-can or dry-film preservation. The commercial technologies for in-can preservation that are currently available are based on 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT) or 2-methyl-4-isothiazolin-3-one (MIT). At present, only limited number of alternatives can be used and are reviewed in this presentation. The examples of non-sensitizing biocidal components for coatings may include quaternary/cationic nitrogen amines, silver ion or zinc complexes. However, the use of the latter is not without risk for human health. Therefore, it is believed that disruptive methods will need to be implemented in parallel with bio-inspired solutions. In particular, the antimicrobial polymers, amino-acid based systems and peptides have similar functions in nature and can offer potential for antimicrobial activities. Also cross-border solutions currently applied in food or cosmetics industries need to be considered as examples that need be adapted for paint formulations. However, the incorporation in paint formulations remains challenging in respect of the stabilization and rheology control of the system. The overview in this work aims to provide different strategies and best evidence for future trends.

Active compounds encapsulation in polymeric carriers is a technology widely used as it protects and improves the physical characteristics of the active compound and controls its delivery. The effectiveness of polymeric microcapsules (MCs) depends on the barrier properties of the polymeric shell; for a given polymer the latter properties are affected by its molecular weight (MW) and crystallinity (x_c). The aim of this study was to modify the MW and x_c of the MC shells via solid state polymerization (SSP). SSP might take place in the amorphous regions of the polymer upon heating at temperatures higher than the glass transition point (T_g), but lower than the onset of melting (T_m). Poly(lactic acid) (PLA) was chosen as the polymeric carrier and coumarin 6 as the encapsulated compound. PLA is a biobased and biodegradable polymer widely used in drug loading systems, and coumarin 6 is a fluorescent hydrophobic drug that can be used as model compound.

SSP effectiveness as a post-encapsulation tool was proven for blank PLA MCs of two molecular weights (MW= 50000 g mol^-1 and 20000 g mol^-1). SSP led to a 40-50% enhancement of the weight-average molecular weight of the polymeric shell and to an enhancement, from 40 % to up to 70 %, of the mass fraction crystallinity in the case of the low MW-MCs. In an attempt to transfer the gained knowledge to the encapsulation systems, coumarin 6 loaded MCs were prepared. The average size of the MCs was measured at 502nm with a polydispersity index of 1.6 while the encapsulation efficiency was found 15 % for a drug loading of 10 %. UV-Vis measurements show that the compound was fully released after 10 days. Coumarin 6 is found to be thermally stable at temperatures used for SSP, while the study of SSP application in the case of loaded MCs is in progress.

Accumulation of plastic material in the environment has a negative impact on wildlife and humans. As most plastics are non-biodegradable and recycling is limited, if not impossible. This issue is addressed by a novel research project called EFFECTIVE, this project connects 12 companies and research institutes that have come together to redesign two of the most widely used materials today: polyamides and polyesters. This aims to develop routes to produce polyamides and polyesters from sustainable renewable feedstock for the obtaining of fibres and films which can be brought into the market. Such materials will be tested to ensure its applicability into different markets, i.e. construction, automotive, primary and secondary packaging and textile and with the potential of being applied into many other markets (fishing, engineering plastics, agriculture, hygiene and personal care). Following a circular economy approach, the sustainability of the value chains will be further enhanced by the demonstration of an improved end-of-life of the developed eco-designed biobased solutions through the application of monomer regeneration. Biobased polyamides 6 will be firstly hidrolized to 6-ACA then converted into caprolactam which is purified so it can be used for the synthesis of nylon. Mechanical recycling will be applied to nylons obtained from 2 different monomers as they are not suitable for polymerization towards the regeneration of original building blocks. Polyesters based polymers and films will be tested in different environments to determine their biodegradation and compostability. Composting will be proceed by anaerobic digestion tests to ascertain energetic recoverability. The project intends to represent a key milestone towards the future industrialization of biobased fibres and films production in Europe foreseeing the mobilization of relevant investments by involved industry partners and fostering the adoption of multi-stakeholders collaboration models to demonstrate effective ways to develop new cases of biobased economy joining environmental sustainability.

In 2020 alone, breast cancer accounts for 2.3 million cases and 680,000 mortalities. Early detection has been known to improve overall survival-rate of breast cancer patients. Thus extensive research has been focused on microRNAs (miRNAs) as diagnostic biomarkers, for their regulatory role in post-transcriptional gene-expression. Hybridization chain reaction (HCR) is an amplification strategy that produces long biopolymeric DNA chains from monomeric DNA hairpin probes. Herein, we present a nanobiosensor that integrates fluorogenic silver nanoclusters (AgNCs) into a HCR system to detect miRNA-155, a commonly upregulated miRNA in breast cancer patients. To prepare this biosensor, DNA hairpins were first mixed with miRNA-155 to initiate HCR. Silver salt was subsequently added and reduced to form fluorescent AgNCs. The performance of HCR was validated through gel electrophoresis. The fluorescence of AgNCs was analyzed qualitatively and quantitatively with UV-transilluminator and spectrofluorometer, respectively. The HCR-AgNCs nanobiosensor exhibited a strong fluorescence enhancement in the presence of miRNA-155. In addition, the nanobiosensor was highly sensitive with a wide linear range between 100 fM and 1 μM, and a limit-of-detection as low as 1.13 fM. Besides, the nanobiosensor also displayed high selectivity towards miRNA-155, with capabilities of discriminating single-base mismatch. In real sample analysis, the nanobiosensor showed exceptional reproducibility and stability when tested with diluted human serum samples. In lieu of current breast cancer and miRNA detectors, the HCR-AgNCs nanobiosensor exhibits relatively similar performance at a miniscule fraction of cost, effort and time required. Likewise, the proposed nanobiosensor potentially offers a non-invasive and safer approach towards the clinical detection of miRNA-155 and point-of-care early diagnosis of breast cancer.

The footwear design and manufacturing process enter a new phase when footwear production cycles become shorter than usual. Clients not only expect a shorter lead time but at the same time acquire different styles, comfort, and good fit. In terms of orthopedic footwear, typically, it takes several weeks or sometimes even longer to manufacture them. One of the most critical time factors here is the custom fabrication lasts, made according to the client's foot, to create personalized shoes. The production of footwear can reduce this lengthy approach strongly with the help of 3D additive manufacturing. Optimized fitting accuracy represents a further advantage, especially in orthopedics production. Companies are starting to adjust 3D technologies to design and develop footwear production throughout the product cycle. Footwear design development is basing on 3D design software that enables changes of the 3D shoe heel and functional properties of footwear for severe foot deformities and disorders. In addition to footwear's available properties, creative design based on 3D allows quick design modification and visualization. The final design of shoes is manufacturing by combining traditional manufacturing techniques.

The aim of the study is to analyze the possibilities of quickly and accurately designing heels for orthopedic footwear according to individual dimensions, to search for the most suitable the study of the possibilities of using different polymers and methods. This work focuses on 3D printed footwear heel using SLS and FDM technology and different thermoplastic materials, as PA12, ABS, and PLA. Data analysis and research results of compression tests were compared with results of theoretical modeling tasks. The theoretical prediction results of compressive loads and ultimate strength are consistent with simulations and experimental results.

Poly(butylene succinate) (PBS) is a bio-based and biodegradable polyester, that can be used in numerous applications ranging from clothing to food packaging and from car industry to biomedical sector (e.g. drug release systems). PBS conventional polymerization method requires the presence of metal-based transesterification catalysts (e.g. titanium-based catalysts) and high reaction temperatures (T>150 °C). However, under these conditions side reactions may occur along with undesirable yellowing.

Green polymerization routes such as biocatalysis are being developed. However, there is a very limited literature on the enzymatic synthesis of PBS. Additionally, in most of the works where high-molecular-weight PBS is produced from the typical monomers (BDO and DES), several drawbacks e.g. the use of various solvents for polymer isolation, the requirement of high vacuum for by-products removal may impede the process scaling up.

On that basis, an eco-friendly, solvent-free, enzyme-based process for the production of PBS was applied. It was conducted in two steps with the use of Novozym 435: the first at 40°C, under atmospheric pressure for 24 h and the second at 90°C, 20 mbar for 2 h. This work focused on the optimization of the second step’s conditions, by varying reaction temperature (80°C-95°C), pressure (20 mbar, 200 mbar) and reaction time (2h, 6h). Based on the optimization results, the process was scaled up (ca. 10 g of product). A free of thermal degradation and metal catalyst residues PBS grade of weight-average molecular weight 4700 g/mol and melting point 103°C was obtained.

Self-assembled nanoparticles based on amphiphilic poly(N-vinylpyrrolidone) (Amph-PVP) were earlier proposed as a new drug delivery system. In current work, we studied antitumor activity of Amph-PVP-based self-assembled polymeric micelles covalently conjugated with the antitumor receptor-specific TRAIL variant DR5-B (P-DR5-B). The Amph-PVP polymer was synthesized by the earlier developed one-step technique (Kulikov et al., Polym. Sci. Ser. D, 2017). To stabilize Amph-PVP associates, the hydrophobic core was loaded with model substance prothionamide. For covalent conjugation with DR5-B, hydrophilic ends of polymeric chains were modified with maleimide, and a DR5-B N-terminal amino acid residue valine was mutated to cysteine (DR5-B/V114C). DR5-B/V114C was conjugated to the surface of polymeric micelles by the selective covalent interaction of N-terminal cysteine residue with maleimide on Amph-PVP.

The cytotoxicity of DR5-B-conjugated Amph-PVP polymeric nanoparticles was investigated in 3D multicellular tumor spheroids (MCTS) of human colon carcinoma HCT116 and HT29 cells, generated by the RGD-induced self-assembly technique (Akasov et al., Int. J. Pharm., 2016). In DR5-B-sensitive HCT116 MCTS, the P-DR5-B activity slightly increased compared to that of DR5-B. However in DR5-B-resistant HT29 MCTS, P-DR5-B significantly surpassed DR5-B in the antitumor activity. Thus, conjugation of DR5-B to the Amph-PVP nanoparticles enhanced its tumor cell killing capacity.

In current study we obtained a new nano-scaled delivery system based on Amph-PVP self-aggregates coated with covalently conjugated antitumor DR5-specific cytokine DR5-B. P-DR5-B overcomes DR5-B-resistance of the human colon carcinoma MCTS in vitro. This makes Amph-PVP polymeric nanoparticles a perspective versatile nano-scaled delivery system for the targeted proteins.

Three-dimensional (3D) bioprinting is an emerging technology that could be used in the generation of 3D cellular structures for tissue engineering applications. The interest in this technology is due to its capacity to enable the fabrication of precise 3D constructs composed of biomaterials laden with living cells, biomolecules and nutrients. The process involving the deposition of cell-laden biomaterials or bioinks on a substrate is referred to as bioprinting. This bioprinting process can be used in the fabrication of living tissues and functional organs suitable for transplantation into the human body.

Notably, the viability of utilising a bioink for bioprinting is dependent on its functionality, mechanical properties, printability and biocompatibility. The bioink must also be able to provide cells with a stable environment for attachment, proliferation and differentiation. To promote the sufficiency of bioinks in 3D bioprinting, several researchers have investigated pathways to enhance ink properties to meet bioprinting requirements, with several synthetic and natural hydrogels developed. These hydrogels are matrices made up of a network of hydrophilic polymers that absorb biological fluids. They can be created from a large number of water-soluble biopolymers including proteins and polysaccharides. The 3D structure of these hydrogels is due to the presence of structural crosslinks that are maintained the environmental fluid. The elasticity of these structures and the presence of a large amount of water enable the hydrogel to adequately mimic biological tissues. Recognising the importance of hydrogels in 3D bioprinting and its potential wide range of tissue engineering applications, the current study therefore investigated major physicochemical parameters that may affect the printability and biocompatibility of biopolymer-based hydrogels. Approaches employed in maintaining structural integrity of the hydrogel, via the application of crosslinking methods were comprehensively discussed with explorations of the status of the formulation and use of biopolymer-based hydrogels for 3D bioprinting, also presented.

Natural polymers play a vital part in the formulation of pharmaceutical dosage forms because of their use as excipients. Synthetic polymers have been introduced into drug delivery recently, the usage of natural polymers in drug delivery research continues to rise. It is not surprising that applications other than its caloric value have been found for starch. Various natural source of the polymer has been focused for delivery systems among them Assam bora rice starch seems to be a better candidate because of interesting properties such as non-toxic, biocompatible, biodegradable, mucoadhesive and non-immunogenic properties. Assam Bora rice, locally known as Bora Chaul, was first introduced in Assam, India, from Thailand or Myanmar by Thai-Ahom, now widely cultivated throughout the Assam. The starch obtained from Assam Bora rice is characterized by its high amylopectin content (i.e., > 95%) with a branched waxy polymer which shows physical stability and resistance towards enzymatic action. Assam Bora rice starch hydrates and swells in cold water, forming viscous colloidal dispersion or sols responsible for its bioadhesive nature. Moreover, it is degraded by colonic bacteria but remains undigested in the upper GIT. Due to the excellent adhesion and gelling capability, it is often selected as a mucoadhesive matrix in a controlled release drug delivery system. Carboxymethyl Assam Bora rice starch has also been applied for SPIONs stabilization and further it's ability to effectively bind and load cationic anti-cancer drug molecule, Doxorubicin hydrochloride (DOX), via electrostatic interaction.This article provides a critical assessment of Assam bora rice literature and shows how the rice can be used in many ways, from food additives to drug delivery systems.

Optical sensors based on surface plasmon resonance (SPR) have made great strides in the detection of various chemical and biological analytes. A surface plasmon is a bound, non-radiative evanescent wave generated as resonant electrons on a metal-dielectric surface absorb energy from an incident light. As analytes bind to a functionalized metal substrate, the refractometric response generated can be used for quantitation with great selectivity, sensitivity, and capacity for label-free real-time analysis. Polymer nanobrushes are ideal recognition elements because of their greater surface area and their wide range of functional versatility. Here, we introduce a simple “grafting-from” method to covalently attach nanometer-thick polymer chains on a gold surface. Nanografting on gold-coated BK-7 glass was performed in two steps: (1) self-assembly of organosulfur compounds; and (2) RAFT-mediated radiation-induced graft polymerization (RAFT-RIGP) of polyglycidyl methacrylate (PGMA). Surface modification was monitored and verified using FTIR, SPR, and SEM-EDS. Layer-by-layer thickness calculated based on Winspall 3.02 simulation fitted with experimental SPR curves showed successful self-assembly of 1-dodecanethiol (DDT) monolayer with thickness measuring 1.4 nm. These alkane chains of DDT served as the graft initiation sites for RAFT-RIGP. Nanografting was controlled by adjusting the absorbed dose in the presence of chain transfer agent, 4-cyano-4-(phenylcarbonothioylthio)pentanoic acid. The molecular weight of grafted polymers measuring 2.8 and 4.3 kDa, corresponded to a thickness increase of 3.6 and 7.9 nm respectively. These stable nanografted gold substrates may be further functionalized for sensing applications.