Aqueous dispersions of biopolyesters have long been used in the drug delivery sector, typically in highly diluted formulations (1-5% or less) [1]. However, when prepared at higher concentrations, they offer new opportunities that were largely unexplored until recently. They can be used to prepare films and polymer coatings in a manner similar to vinyl polymer dispersions.
Compared to these, they offer significant environmental advantages due to their biodegradability and inherent recyclability. In our research group, we have managed to obtain biopolyester dispersions with solid concentrations up to 40%, which are stable for at least six months [2-3]. These dispersions have been applied as coatings on paper, providing resistance to water and oil, while maintaining the biodegradability and recyclability of the paper [3]. The dispersions can also be simply used to prepare environmentally sustainable blends with water-soluble polymers, such as polyvinyl alcohol [4]. They can be mixed with easily dispersible fillers, such as graphene oxide (GO) to produce an electrochemical sensor after the grafitization of GO. Finally, they also facilitate the easy incorporation of thermolabile bioactive molecules, such as osteogenic peptides, which were successfully incorporated into PLA films and tested as substrates for stem cell growth and differentiation.

Functional polymer films are a group of smart surface coatings for the design of intelligent interfaces. Due to their specific physicochemical properties, which have been intensively investigated regarding fundamental aspects in the last decades, this form of surface modification is also promising for various applications. The obstacles for the transition into a real application are the transfer of the preparation from small model surfaces to technically relevant substrates and coating processes, the scalability as well as the specific requirements of technical processes. This means that the laboratory approach has to be adapted to the standards of coating processes.
We present a novel coating based on a bio-inspired phosphorylcholine co-polymer as an example for this adaption, resulting in a nano-coating with simultaneous anti-fog, anti-fouling, ice-reducing and easy-to-clean properties1-4. It will be demonstrated that all these applications are fundamentally based on the chemical structure of poly(phosphorylcholines) and the specific interactions with water molecules. The versatility of the polymer concept and the coating process developed enable the functionalization of diverse substrate types using various commercial methods. We also address the key question of how the mechanical and chemical stability of such films can be increased. By controlling the degree of cross-linking and tailoring the coating conditions, layers with high stability in water (>100 days) and high abrasion resistance (>1000 cycles) can be achieved.
Basically, the studies demonstrate that an exactly balanced ratio between thickness of the dry films, degree of swelling and water contact angle is necessary to create such multi-functional surface coatings.

Properties of covalently cross-linked polymer networks can be tailored by the chemical structure and nature of building blocks or branching density. Proper selection of these parameters allows obtaining robust materials with good mechanical and dimensional stability, desirable for practical applications as hydrogels.[1] Introducing porosity to network structure may bring more benefits for the material, like increasing elasticity and improved water sorption. Our research aimed to obtain covalent networks from reactive polymers: poly(2-isopropenylo-2-oxazoline) (PiPOx) and carboxyl functionalized polyesters (HOOC-PLA-COOH and HOOC-PCL-COOH).[2,3] Obtained results show that in the used system, the direct formation of amphiphilic networks can be efficiently achieved without any catalysts or byproducts, as the result of an addition reaction between the carboxyl-terminal groups with pendant groups distributed along PiPOx chains. Carrying out the process in the presence of a water-soluble porogen (NaCl) allowed obtaining porous hydrogels that could be formed to the desired size and shape while maintaining stable dimensions (Fig. 1).

Fig. 1. Porous PiPOx-polyester networks synthesis

The obtained materials were characterized in terms of composition, mechanical properties, water sorption capacity and biocompatibility. Our findings indicate that selected hydrogels can serve as artificial matrices, effectively mimicking scaffolds to support cell growth.

Acknowledgments: Financial support from the National Science Centre, Poland, Grant No. 2020/37/B/ST5/03302 is gratefully acknowledged.

Nowadays, in vitro diagnostic (IVD) methods face non-specific interactions increasing their background level and influencing the efficacy and reproducibility. The most emploied blocker of non-specific interactions is now-a-day bovine serum albumin (BSA), an animal product facing some disadvantages like its batch-to-batch variability and contamination with RNAses. Herein, we have developed amphiphilic water-soluble synthetic copolymer tools based on the highly biocompatible, non-immunogenic and non-toxic methacrylamide-based copolymers or polyoxazolines, which can serve as highly effective synthetic blockers of non-specific interactions and an effective BSA alternative (1). The highest blocking capacity was observed for polymers containing two hydrophobic anchors taking advantage from combination of two structurally different hydrophobic anchors. Polymers prepared by free radical polymerization with broader dispersity seems to be a slightly better in term of better surface covering. We demonstrated in sandwich ELISA system evaluating human Thyroid Stimulating Hormone in real patient’s samples, that our polymers can fully replace BSA without compromising the assay results. Importantly, as fully synthetic material the developed polymers are fully animal pathogen free thus they are highly important materials for further development. Moreover, the developed materials should be also used in other biotechnological methods, such as Surphase plasma resonance, microfluidics and PCR.
Acknowledgement
This work was supported by the Technology Agency of the Czech Republic. (project no. FW11020013).

Poly(2-oxazoline)s (POx) are a group of polymers, which have attracted substantial research interest in previous years. Besides considerable physicochemical as well as biocompatibility advantages over the gold-standard poly(ethylene glycol) (PEG), POx also show a much wider chemical variety than PEG. This was illustrated by diverse polymer architectures as well as polymer analogue reactions in the past. However, due to the broad chemistry of POx, there are lot of further possible applications.
This talk focusses on the versatility of endgroup-functionalized POx for a variety of applications. It will be demonstrated that endgroup functionalization is basis for cancer therapy, cancer preventing vaccination, tissue engineering as well as widely applicable surface modifcation.

Prostate-specific membrane antigen (PSMA) is a well-recognized biomarker for diagnosis and targeted therapy of prostate cancer. However, the developed PSMA-targeted agents like peptides, and nanoparticles have a short systemic circulation and rapid metabolic degradation, which limits their ability to effectively reach tumor sites while also increasing the risk of off-target accumulation in normal organs like kidneys. Herein, we developed a modular 4-arm star poly(2-oxazoline)-based block copolymer (s-POx) platform for constructing homomultivalent radioligands, which aimed at enhancing tumor uptake, prolonging systemic circulation, and increasing tumor residency for more effective radiotherapy. An ethyl isonipecotate-terminated block copolymer, (pBynOx-rand-pMeOx)-b-pMeOx, was synthesized via cationic ring‐opening polymerization (CROP) using a pentaerythritol tetrakistriflate initiator, where BynOx and MeOx are 2-butyne-2-oxazoline and 2-methyl-2-oxazoline, respectively.[1,2] The alkynyl groups of the synthesized s-POx were covalently conjugated with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) radiometal chelators via CuAAC using the Benedict/glucose reagents (s-POx-DOTA).[3] The DOTA molecules were labeled with either diagnostic gallium-68 for imaging with positron emission tomography or therapeutic lutetium-177 for radioligand therapy. The radiolabeling of s-POx-DOTA with gallium-68 showed excellent radiochemical yield (90±7%, n=4), purity (>99%, n=4), and in vitro radiolabel stability in various physiological media, which provides a promising basis for the subsequent labeling with lutetium-177. s-POx with/without two copies of PSMA-targeting ligands were successfully synthesized and characterized, and the in vitro cell assays and in vivo therapeutic efficacy are underway. Moreover, this multivalent s-POx strategy holds promise for delivering various cytotoxic payloads, such as carborane for boron neutron capture therapy, to treat different types of malignancies.