Due to overuse and misuse of common antibiotics an increased development of resistant pathogens has been observed. Therefore, new antimicrobial materials that may prevent the usage of antibiotics in the first place have become of great interest. [1,2] One field of application is dental implantology. Since the body does not immediately form a fibrous connection between implant and gum tissue, pockets remain (fig. 1). [5] These areas are not accessible from the outside and biofilms start to form, thus postoperative infections are among the most common side effects regarding dental implants. By coating the titanium socket of said implants with polymers that exhibit antimicrobial properties, infections may be averted completely. [1,2] Guanidine and biguanide derivatives are long known to have antimicrobial activity. Due to their strong basic nature they are protonated in biological environment and the resulting cation acts as a bidentate ligand towards the negatively charged phospholipid membrane of the bacterial cell wall, potentially surpassing the antimicrobial activity of QAC based counterparts. [3,4] However, most guanidine and biguanide synthesis require very specific reactants combined with harsh reaction conditions such as high temperature which is not always compatible with other functional groups, especially vinyl groups. [3,4] The aim of this work is the design of different guanidine and biguanide based monomers that can potentially be copolymerized by means of RAFT polymerization with monomers containing phosphonic acid groups acting as molecular anchors, [1,2] thus enabling the grafting of the respective polymers directly onto the titanium socket of the dental implant.

Skin cancers are among the most common malignancies, demanding innovative therapeutic approaches. Injectable hydrogels offer a minimally invasive solution for deep tissue wounds by conforming to irregular geometries, maintaining a moist environment, and enabling localized drug delivery. This study introduces an oxidized pectin (OP)-gelatin hydrogel dynamically crosslinked via adipic acid dihydrazide (ADH) and gelatin, providing enhanced structural integrity and self-healing properties [1]. Procaine (PC) is incorporated for its dual role in pain relief and anticancer activity [2], while propolis strengthens mechanical properties and contributes antioxidant, antimicrobial, anti-inflammatory, and anticancer effects[3,4]. Additionally, antibacterial activity, mucoadhesive nature, and pH-responsive gelation of pectin polymer further enhance the hydrogel’s functionality [2].
All formulations were characterized using FTIR, TGA, contact angle measurements, rheological, mechanical, degradation, swelling, and drug release analyses. The findings indicate that propolis incorporation enhanced the hydrogel’s mechanical strength, self-healing ability, and controlled drug release properties. Rheological analysis revealed a decrease in the damping factor with the addition of propolis, suggesting improved viscoelastic stability. The lap shear test (ASTM- F2255-05) demonstrated an adhesive strength of 1.544 MPa, highlighting the hydrogel’s ability to form robust adhesion with wound tissues. The system facilitated sustained PC release, offering prolonged analgesic efficacy and improved therapeutic potential for skin cancer treatment. This multifunctional hydrogel system presents a promising approach for skin cancer treatment by facilitating tissue regeneration, enabling sustained pain management, and promoting efficient wound healing through bioactive agent delivery.

Surface modification of lipid carriers via PEGylation prevents particle aggregation and imparts "stealth" properties, enhancing their circulation time in the bloodstream. However, PEGylation presents several limitations, including the ABC (accelerated blood clearance) effect, which leads to rapid elimination of the drug upon repeated administration, hypersensitivity reactions, and the so-called "PEG dilemma" which limits the cellular uptake and endosomal escape. Recent studies emphasized the benefits of using poly(N-methyl vinylacetamide) (PNMVA) as alternative to PEG for developing non-toxic, efficient, and less immunogenic lipid-based carriers, in particular siRNA-loaded lipid nanoparticles. [1-3] This communication will present the precision synthesis of a series of lipid-poly(N-methyl vinylacetamide) conjugates by reversible addition-fragmentation chain transfer (RAFT) polymerization and explore their potential for decorating lipid nanocarriers. The lipid structure and polymerization degree of PNMVA were varied to assess the impact of these parameters on the interaction of the lipid-PNMVA conjugates with lipid bilayers and on the structure and surface properties of the resulting lipid nanocarriers.

Gene therapy holds great promise for treating various diseases but relies on safe and efficient delivery vectors for genetic material.[1] Polymers bearing cationic sites can form polyplexes via electrostatic interaction with nucleic acids (NAs). This increases circulation times in the bloodstream by shielding the payload and enhances cellular uptake.[2] However, depending on their structure, polymers with pronounced positive charge may exhibit significant cytotoxicity.[2,3] Therefore, charge density and molecular architecture of polycations must be carefully selected to balance desired and adverse effects.

Our work focuses synthesizing statistical copolymers of cationic Vinylamine (VAm) and charge-neutral hydrophilic N-Vinylpyrrolidone (NVP). VAm was introduced via polymerization of N-Vinylformamide (NVF) and subsequent acidic hydrolysis. The polymers were prepared using photo-iniferter reversible addition-fragmentation chain-transfer (PI-RAFT) polymerization, yielding well defined macromolecules with low polydispersities (Đ = 1.2–1.4). To tailor charge density, we varied the ratio of NVF to NVP in monomer feed. The synthesized polymers show more than 10-fold greater biocompatibility compared to linear Polyethyleneimine and the liposomal carrier Lipofectamine 2000, along with as up to 14-fold increased gene delivery efficacies in luciferase plasmid assays.

To further dictate the shape of polyplexes and modulate their properties as well as NA availability, we prepared sequential bottle brush copolymers via RAFT polymerization, incorporating a block of Polyethylene glycol (PEG), as well as a block containing PVAm-stat-PNVP grafts using a combined grafting-through/grafting-from approach. This architecture aims to reduce cytotoxicity by using PEG grafts to shield the PVAm-NA-polyplex, while still enabling intracellular disassembly and NA delivery.

Due to their high tunability, Antimicrobial polymers (APs) have emerged as promising materials to tackle challenges associated with antimicrobial resistance (AMR).¹ However, traditional APs consist of cationic and hydrophobic units², which result in inherent toxicity due to their amphiphilicity nature³. Herein, a non-amphiphilic APs were developed and investigated. This platform combined cationic monomers with hydrophilic units capable of forming hydrogen bonds. The rationale behind the design is that non-amphiphilic APs remain isolated in solution until they come into contact with negatively charged bacterial membranes, where they start attracting each other and cluster through hydrogen bonds. This approach allows for enhanced local concentration of polymers to disrupt bacterial membranes while reducing unspecific toxicity associated with hydrophobicity. Minimal inhibitory concentration (MIC) and hemotoxicity tests revealed that a subset of polymers exhibited significant antibacterial activity with little to no effect on mammalian cells, particularly when the cationic charge and specific subunit ratio were balanced at 50:50. This study emphasizes that hydrophobicity is not an essential quality in APs, presenting non-amphiphilic polymers as new motif for AP designs.

Ibuprofen (IBU) is a commonly used non-steroidal anti-inflammatory drug (NSAID). However, its low water-solubility and low bioavailability necessitate frequent doses. But, extended IBU exposure can give rise to gastrointestinal or heart problems, therefore it would be beneficial to deliver the drug in controllable ways targeting the affected tissue.
In this study, a poly(β-amino ester) (PBAE)-based hydrogel was proposed as a delivery system for IBU to increase solubility, stability, bioavailability and efficacy of the conjugated IBU and targeting of certain tissues.
PBAEs are biodegradable and biocompatible cationic polymers used for gene transfer, tissue engineering and drug delivery applications (1). They are used as efficient delivery of drugs to the cartilage due to electrostatic attraction between the negatively charged constituents of cartilage and the positively charged sites on the PBAE (2). Some of these sites also serve for conjugation of IBU in our work.
The PBAE macromers for hydrogel synthesis were obtained in a three-steps process: preparation of acrylate-terminated polymers from reaction of PEGDA (Mn = 575 g/mol) and 5-amino-1-pentanol, protonation of the amine groups with 1% acetic acid (pH 5.5) and conjugation of IBU sodium salt on the amine groups by electrostatic interactions. The macromer was used in the synthesis of PEGDA hydrogels, which were found to release %60 of IBU in 26 hours. The salt nature of the hydrogel system not only promotes higher bioavailability and solubility of IBU, but possibly gives targeting ability of tissue with negatively charged sites, such as cartilage or mucus.

Acknowledgement: Bogazici University (BAP 20049).

In response to the global rise in antibiotic-resistant bacteria 1, significant research efforts are being devoted to developing new effective antibacterial drugs.
This study draws inspiration from natural antimicrobial peptides (AMPs), that are macromolecules able to selectively disrupt bacterial membranes, due to their amphiphilic nature 2. Key features of these systems, are the presence of cationic and hydrophobic groups in their structure.
We synthesized a library of well-defined amphiphilic random and block copolymers using bio-based acrylates, respectively containing amino acids with various side chains (Ala, Phe, Lys) as the cationic components, and tetrahydrogeraniol (THG) as the hydrophobic component, employing controlled Reversible Addition-Fragmentation chain Transfer (RAFT) polymerization 3. The antimicrobial activity and cytotoxicity of these copolymers were evaluated against E. coli, S. aureus, and mouse fibroblasts (L929). Both random and block copolymers displayed antimicrobial activity influenced by the cationic/hydrophobic balance, yet block copolymers provided greater control and improved selectivity, particularly in Lys-based variants that achieved potent activity against E. coli and moderate efficacy against S. aureus. Random copolymers typically required higher cationic content for comparable antimicrobial activity, risking elevated cytotoxicity. In contrast, block copolymers—especially those with an equimolar ratio of cationic and hydrophobic segments—offered superior antimicrobial performance and lower toxicity, highlighting their potential for more targeted and biocompatible applications. Live/dead staining and SEM imaging confirmed that its antimicrobial effect was achieved through disruption of the bacterial cell membrane integrity.

Keratoplasty is one of the most successful transplantation procedures worldwide. It is the preferred treatment when the cornea’s transparency is compromised, particularly in cases of endothelial dysfunction, often leading to corneal edema. Corneal transplantation remains the best therapeutic choice to improve visual acuity, despite the high cost, the lack of donors, and the associated surgical risks.¹ However, in cases of chronic disorders or several transplant failures, artificial corneas are considered valid alternatives.² Hard keratoprostheses, such as Boston KPro type I, remain a viable option; however, they do not eliminate the need for donor corneas and the challenges in biointegration with the stromal wall. The development of soft keratoprostheses, including AlphaCor™, made from synthetic and inert materials, has led to implants easier to handle, thanks to their suitable mechanical properties, simplifying the surgical procedure.³ In particular, a recent device, EndoArt®, made of hydroxyethyl methacrylate and methyl methacrylate, is capable to replace the diseased endothelium layer.⁴ Such artificial device works as an impermeable barrier, preventing fluid influx and reducing corneal edema. However, the most important unsolved issue lies in the implant detachment from the stromal surface. In this context, in the present contribution novel aromatic copolyesters with different compositions, containing a sulphur-based polar group, were successfully synthesized. Compression-moulded films were subjected to molecular, thermal, mechanical and surface characterization, as well as to biocompatibility evaluation through in vitro cytotoxicity tests. The results obtained show that the copolymer with low comonomeric unit content could be suitable for corneal transplantation.

Polymer blends can play a key role in the transition towards more sustainable materials and production processes. The technological relevance of these materials is clear, but a deep understanding of their chemical physics is still lacking; phase separation and immiscibility are the rule, not the exception, for polymer blends, and gaining the ability to predict why and when this would happen opens the possibility of designing novel materials (and processes) with desired properties. Knowing the phase diagram before processing would allow precise control of the microstructure (which determines the macroscopic behaviour) of polymer blends. Phase diagrams can be determined from bulk thermodynamics, which allows to predict system miscibility conditions. The Flory-Huggins theory, which assumes incompressibility of the system, is the most common starting point for this study, both for its simplicity and capability to capture some essential features of polymer mixtures. The lattice fluid theory introduces compressibility and can naturally predict phenomena such phase separation upon heating (and the so called ‘LCST’, the lower critical solution temperature), moreover it gives the opportunity to link the bulk physics to the interface, that determines the compatibility of two polymer. In this work, the Pressure-Volume-Temperature (PVT) properties of different polymers are experimentally investigated and used to model their miscibility and interfacial properties with the aim of better understanding the physical-chemical processes and properties that underlie them, and to pave the way for predicting the properties that a compatibilizer should have to achieve the desired level of compatibilization for industrial applications.

Nowadays, polyurethanes (PU) are listed among the most versatile families of polymers. They are used in a wide range of applications, from foams to hydrogels. Within the hydrogel sector, PU are found in various formulations designed for different uses, such as water depollution, wound dressing, and drug delivery. This wide application range is due to the large diversity of commercially available PU building blocks, allowing to achieve various physico-mechanical properties. However, PU are increasingly becoming the target of regulations due to their traditional synthesis method, which involves the use of di-isocyanates. These chemicals have been proven to be strong irritants and are also flammable and explosive. Furthermore, their synthesis requires hazardous chemicals, as di-isocyanates are produced through the phosgenation of amines.
To address the need for safer PU formulations, non-isocyanate polyurethanes (NIPU) have been investigated. A promising strategy lies in the reaction between polyamines and α-alkylidene bis-cyclic carbonates, which forms a polyoxazolidone-based material. Indeed, many polyamines are readily available and the structure of the spacer of the bis-cyclic carbonate can be modified to fine-tune the mechanical properties of the resulting material. Here, based on this strategy, we synthesized a variety of NIPU hydrogels by exploring the reaction of Jeffamine with bis-cyclocarbonates exhibiting different spacers in the presence of a crosslinker. We investigated the impact of the NIPU formulation composition on the mechanical properties of the resulting networks in the dry state so as of the hydrogels obtained by swelling in aqueous media.

Structural colours, which arise from the physical interaction of light with nanoscale long-range ordered structures, offer a sustainable and highly tuneable alternative to conventional colorants, such as synthetic pigments and dyes. These traditional colorants often suffer from environmental concerns, limited colour control, and colour fading. Photonic crystals (PhCs), instead, exhibit structural colouration and can be manufactured easily and inexpensively with a bottom-up approach, fabricating periodic nanostructures through self-assembly of, for instance, block copolymers. In particular, bottlebrush block copolymers (BB-BCPs) rapidly self-assemble into ordered morphologies, generating a photonic bandgap of visible wavelength. This makes them promising candidates for photonic crystals applications. However, bio-based BB-BCPs remain unexplored.

In this work we investigate the design of stimuli-responsive photonic crystals made of bio-based BB-BCPs, by incorporating cyclic and acyclic terpenes, terpenoids, and biodegradable polymers such as polylactic acid (PLA). We plan to employ orthogonal controlled polymerizations such as reversible addition−fragmentation chain-transfer polymerization (RAFT), atom transfer radical polymerization (ATRP), and ring-opening polymerizations (ROP) to achieve precise grafted backbone chains endowed with two different incompatible side chain materials. To probe microstructural order and unravel the mechanism of self-assembly, we will employ advanced characterization techniques including small-angle X-ray scattering (SAXS), and scanning electron microscopy (SEM). Surface and colour analysis is conducted with polarized optical microscopy (POM), diffuse reflection spectroscopy, and ellipsometry. In this poster contribution I will share my basic ideas and the preliminary results about this exciting project.

Thin polymer films capable of reversible coil-to-globule transitions in response to external stimuli have garnered significant attention for applications in functional materials, including sensors, nanoswitches, and responsive coatings. These transitions can be triggered by factors such as temperature, pH, or consolvent addition, leading to structural and morphological changes that influence the film swelling behavior under different levels of relative humidity [1,2]. Among these stimuli, light stands out as a non-invasive, high-resolution trigger enabled by photoswitchable molecules like azobenzenes. Azobenzenes undergo a reversible double-bond isomerization when exposed to specific wavelengths of light, with the process being reversed either through irradiation with a different wavelength or by thermal relaxation. However, the light-induced changes in structure and morphology in thin films remain to be examined.
To address this, we investigate the swelling behavior of statistical copolymer films consisting of azobenzene-acrylamide and N,N-dimethylacrylamide in both isomeric states of the photoswitchable molecule azobenzene. The impact of UV irradiation on swelling in water vapor is examined, with the aim of controlling water uptake, expansion, and nanoscale morphology. We use time-resolved FTIR spectroscopy to monitor group vibrations during swelling and irradiation, gaining insights into molecular interactions throughout the isomerization process. Additionally, in situ time-of-flight neutron reflectometry on a thin film using the D17 instrument at ILL provides time- and depth-resolved data on water distribution. The results shed light on the interplay of light-induced morphology changes and interface effects in photoresponsive thin polymer films.

Recent advancements in the field of emissive materials for OLEDs have been characterized by two predominant trends. Firstly, there has been a notable inclination toward the thermally activated delayed fluorescence (TADF) mechanism of electroluminescence, a phenomenon that facilitates the attainment of high quantum yields without the necessity of using heavy metals. Secondly, there has been a transition from low-molecular-weight emitters to polymers, a shift that significantly streamlines the OLED manufacturing process by enabling the utilization of "wet" methods (spin-coating, inkjet printing, etc.) instead of expensive vacuum deposition. In addition, polymeric emitters are characterized by much higher morphological and thermal stability than organic TADF materials that allows devices based on them to be exploited longer [1,2].
In our work, a new strategy for the synthesis of polymeric through-space charge-transfer TADF emitters with tunable colour of the emission from blue to orange is reported (Figure). The strategy is based on RAFT-mediated alternating copolymerization of styrene-based donor monomers with acceptor maleimide-type monomers. Most of these alternating copolymers exhibit exciplex emission via through-space charge-transfer mechanism and display aggregation-induced emission. The alternating copolymers in solid state demonstrated delayed fluorescence with the lifetimes in the range between 0.35 and 6.2 µs making them promising materials for emitting layers of OLEDs. Indeed, multicolor hosts-free solution-processable TADF OLEDs were fabricated using the synthesized copolymers as blue, green and orange emitters. The devices showed good stability of electroluminescence spectra at the different voltages, with the highest external quantum efficiency of 7.84 % was reached for green device [3].

Current research aims to foster a circular economy for biobased and biodegradable plastics, particularly for applications like food packaging. Moving beyond composting, these studies enhance recyclability through eco-design strategies that enable multiple end-of-life loops, extending material use and reducing environmental impact [1]. Key objectives are to identify polymer properties that support recyclability, focusing on the trade-off between decontamination and structural stability, and to develop recycling processes that preserve or improve mechanical and thermomechanical properties over cycles.
This investigation examines biopolyesters, including polylactic acid (PLA), polyhydroxybutyrate-co-valerate (PHBV), polycaprolactone (PCL), polybutylene succinate (PBS), polybutylene adipate-co-terephthalate (PBAT), with polyethylene terephthalate (PET) as a reference, as they undergo aging, contamination, decontamination, reprocessing, and stabilization [2]. Advanced characterization techniques—including differential scanning calorimetry (DSC), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and dynamic mechanical thermal analysis (DMTA)—are employed to analyze changes in crystallinity, thermal stability, and mechanical properties. Molecular weight distribution and crystalline structure are also assessed to determine features that support stability during recycling.
By analyzing chemical degradation products, particularly non-intentionally added substances (NIAS) and their interaction with contaminants, this research identifies factors affecting the food contact ability of recylates [3], essential for food packaging application.
Through these studies, a foundation for eco-designing recyclable and stable biopolyesters is created, aiming to develop plastics that maintain integrity across recycling processes and align with a circular economy. Enhanced end-of-life options thus enable biodegradable plastics to contribute sustainably to long-term economic and environmental goals [4].

The development of solution-processable deep blue electroluminescent materials has gained significant research attention.1 Higher dimensionality in conjugated systems can result in distinct solid-state superstructures that may exhibit unique optical and electronic properties.2 Conjugated polymer networks which belong to higher dimensional polymer with extended π-conjugation and permanent micropores have garnered significant research attention owing to their high chemical stability, adjustable pore structures, high specific surface areas, and reversible redox chemistry. These materials show a broad range of applications in numerous fields such as catalysis,3 energy storage, sensing,5optoelectronics, and many more. Here, we have demonstrated the synthesis of two conjugated polymer networks made of triazine and fluorene that are solution-processable, highly fluorescent, and have a wide band gap (Figure 1a). To examine the impact of side-chain polarity on the fluorescence and electroluminescence characteristics of the polymer, two distinct side-chain alkyls, and ethylene glycol are introduced to the polymer backbone. The polymer network with an alkyl side chain displays a deep-blue luminescence whereas its ethylene glycol counterpart exhibits green. When used as an emissive layer after doping in TCTA matrix in electroluminescence device, both the polymer shows deep blue electroluminescence (Figure 1b). The maximum quantum efficiency (EQE) of OLEDs based on FCPN2 (ethylene glycol chain) is 2.7%, which is significantly higher than the 0.5% displayed by FCPN1 (alkyls side chain). These findings underscore the potential of sidechain polarity to tune the fluorescence and improve electroluminescence performance of conjugated polymer based blue OLED devices.

Nowadays, Researchers are focusing on replacing conventional energy with green renewable solar and wind energies. For the development of clean and sustainable fuel, hydrogen must be generated through metal-free electrocatalyst water splitting.1,2 The development of efficient, cost-effective, metal-free catalysts for water electrolysis that can compete with platinum-based systems remains a persistent challenge. Conjugated polymer networks have emerged as promising candidates for the electrocatalytic hydrogen evolution reaction (HER).3–5 Herein, we have designed two triazine-based conjugated polymer networks (TCPNs) - TCPN1 and TCPN2, by Suzuki-coupling of triazine acceptor core with phenyl (donor) or thiophene (donor) units, respectively, via a phenyl spacer. Experimentally, the pristine TCPN1, with a larger bandgap, exhibited a high overpotential (535 mV) to achieve a current density of 10 mA cm-², while TCPN2, with a narrower bandgap, exhibited slightly improved performance (457 mV). Strikingly, electrochemical activation of both catalysts via prolonged negative potential polarization (-0.40 V vs RHE) for 5 hr dramatically enhanced their HER activity. Post-activation, TCPN2 achieved 10 mA cm-² at a significantly reduced overpotential of 211 mV, outperforming TCPN1 (293 mV) and many reported metal-free catalysts. This work underscores the critical role of electrochemical activation in optimizing HER activity and establishes a robust framework for designing metal-free electrocatalysts. The insights presented here advance the rational design of efficient and sustainable alternatives to noble metal-based electrocatalysts.

With the aim to fabricate covalently crosslinked hydrogels, Hyaluronic Acid (HA) was derivatized with thiol groups to obtain Thiolated Hyaluronic Acid (HA-SH) [1-3]; Gelatin Methacryloyl (GelMA) was instead synthesized via a covalent reaction between methacrylic anhydride (MA) and the amine and hydroxyl groups of Gelatin [4].
Both HA-SH and GelMA, together with their precursors HA and Gelatin, were analyzed by using solution Nuclear Magnetic Resonance (NMR) spectroscopy [3-5]. The focus of the spectroscopic investigation was the confirmation of the derivatization processes, the determination of the degree of substitution (DS for HA-SH and DM for GelMA), and the characterization of the derivatized polymers. Moreover, the applicability of low-field NMR (80 MHz) in the analysis of biopolymeric derivatives was evaluated in comparison with high-field instrumentation (700 MHz).

Funding by European Union (NextGeneration EU), through the project PRIN 2022 "3D-BIOSAME – A 3D BIOprinted SpinAl cord Model to reach functional meaningful and clinically translatable rEgeneration" (grant number 2022YY9AR2) is gratefully acknowledged.

Electron Paramagnetic Resonance (EPR) is a spectroscopic technique sensitive and selective to paramagnetic compounds. Since a large number of depolymerization processes occurs through radicalic mechanisms, detection of intermediate radical species through EPR is particularly important for elucidating the depolymerization mechanism. The radical intermediates formed during the process are often short-lived and cannot be directly observed on a typical EPR time scale. In this case spin traps can be used, consisting in molecules highly reactive towards radical species, which give rise to stable EPR-detectable radicals. The hyperfine splitting patterns allow to identify the trapped radicals. The lineshape analysis of the signals provides information about radical mobility, related to the viscosity of the polymeric medium. Our in-situ setup, including a home-built EPR resonator, allows to monitor the reactions at high temperatures, control the reaction atmosphere and is therefore of crucial importance for obtaining information relevant for the operational reaction conditions.
This overview covers several examples of EPR studies on depolymerization in which our group is involved, including thermally, chemically and optically induced depolymerization for such diverse applications as, for instance, visible light-induced recycling of commercial polymethacrylates [1] and oxidative degradation of aromatic hydrocarbon-based proton-exchange fuel cell membranes. [2]
EPR has proven to be a powerful method for gaining valuable mechanistic and structural insights into depolymerization. processes.