Reversible deactivation radical polymerization (RDRP), such as atom transfer radical polymerization (ATRP), enables controlled polymer synthesis but generates dead chains, broadening the molecular weight distribution (MWD). While previous studies successfully separated living and dead chains in polystyrenes using solvent-gradient HPLC (SG-HPLC),[1][2] extending this approach to polyacrylates presents challenges due to their ester-functionalized backbone, which limits separation efficiency in conventional HPLC systems (Figure 1).
To address this limitation, we introduced dihydroxyl-functionalized end groups via azidation followed by copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC). These dihydroxyl groups significantly enhance interactions with a silica-based stationary phase, enabling selective fractionation of living chains from dead chains. By tuning solvent polarity, we achieved distinct elution behavior, with hydroxyl-functionalized living chains exhibiting delayed elution due to their stronger polar interactions. MALDI-TOF MS analysis confirmed that the molecular weight distribution of the isolated living chains closely follows a Poisson distribution, validating the precision of this separation method.
This approach provides a reliable strategy for isolating well-defined living chains, enabling the synthesis of block copolymers with enhanced structural uniformity and tailored material properties.

The inevitable spoilage of food products poses a risk to every consumer, and therefore the need to develop systems for real-time monitoring of food quality arises. In this regard, intelligent packaging systems are being developed that include natural pH-sensitive indicators. In this study, two types of biopolymer matrices, chitosan-starch and starch-gelatin, enriched with anthocyanins from purple cabbage extract were used to monitor chicken breast freshness. The anthocyanins act as natural pH-responsive sensors and as such they exhibit visible color changes in response to spoilage-related pH variations. The key properties of the films: mechanical characteristics (tensile strength, elongation at break, and Young’s modulus), moisture content and water vapor permeability, optical properties (transparency and UV-VIS absorbance) and color stability during storage were evaluated to determine if they are suitable for intelligent packaging applications. The effectiveness of the films in detecting chicken breast freshness was assessed under different storage conditions: 4°C and 25°C. The findings suggest that the films effectively detect chicken breast spoilage while maintaining sufficient mechanical integrity and stability. Anthocyanin-enriched films not only provide enhanced functional properties but also offer a promising approach for intelligent packaging solutions.

Hydrogels formed through dynamic Schiff base cross-linking exhibit superior biocompatibility, remarkable self-healing, and robust cellular adhesion. This study introduces an innovative hydrogel composed of oxidized pectin (OP) and gelatin, enhanced by integrating protocatechualdehyde (PCA) and the local anesthetic procaine (PC). Pectin—a naturally derived polymer with abundant functional groups—displays considerable potential for delivering bioactive agents [1]. Gelatin, characterized by its cell adhesion properties, and coagulation capabilities, offers notable benefits for skin regeneration. Moreover, PCA, a phenolic aldehyde presents in sources such as barley and grape leaves imparts potent antioxidant and therapeutic effects [2].
To prepare OP, a 3% (w/w) pectin solution was oxidized with sodium periodate, dialyzed for two days, and subsequently combined with gelatin. PCA was then introduced at a 1:10 ratio relative to PC, forming the final hydrogel. The developed formulations were thoroughly examined using Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, rheological (oscillatory mechanical spectra, thixotropic strain sweeps, and creep analyses), lap-shear (ASTM F2255-05:), swelling and degradation, contact angle, and antioxidant assays.
Rheological analyses indicated cohesive properties, with a flow point exceeding 100% strain, thixotropic and shear-thinning behaviors—indicative of self-healing and shape-fitting capacity. Additionally, the hydrogel demonstrated strong tissue adhesion, facilitating the sealing of irregular wounds. UV-spectral data indicated sustained release of PCA (280 nm) and PC (293.3 nm), reaching 67.6% (drug/g-hydrogel) within 200 minutes. Coupled with notable antioxidant activity (98.89% DPPH inhibition), these attributes underscore the promise of this injectable, self-healing hydrogel for regenerative medicine and wound healing applications.

Alginate is a natural polysaccharide polymer that is widely used in medical applications due to its biocompatibility, good processability with ionic crosslinking ability, and environmental sustainability [1]. Poly(vinyl pyrrolidone) (PVP) is a synthetic polymer with a high-water retention capacity, and good chemical stability and has various applications in the biomedical field. [2]. This study aims to develop alginate and PVP-based injectable hydrogels for use in biomedical applications. Calcium ions were preferred as crosslinkers. The effects of three different crosslinker concentrations (0.5%, 0.6%, and 0.7%) and two different alginate concentrations (4% and 6%) on hydrogel properties are investigated.
Surface morphology was studied via scanning electron microscopy, chemical analysis via Fourier transform infrared spectroscopy, thermal properties via differential scanning calorimetry, and thermogravimetric analysis. Furthermore, swelling and degradation tests were performed to determine water retention capacity and structural integrity over time, while contact angle assessed surface wettability and hydrophilicity. Also, In vitro cell viability experiments were performed to evaluate cytocompatibility.
The findings suggest that divalent ion-mediated crosslinking, along with variations in alginate ratios, plays a crucial role in modifying the mechanical properties, stability, and physicochemical behavior of the hydrogels. These findings underscore the suitability of the developed hydrogels for biomedical applications, particularly in tissue engineering, drug delivery, and regenerative medicine, where biocompatibility, controlled degradation, and mechanical robustness are essential.

Injectable hydrogels have become highly valued in polymer science and medical applications due to their biocompatibility, flexible mechanical properties, and ability to mimic the extracellular matrix. This study investigates the effects of adding 2-thiobarbituric acid (TBA) on the structural and functional properties of hydrogel systems. It is known that TBA improves mechanical properties and increases cell proliferation in film-type wound dressings [1,2]. In this study, the effects of TBA on an injectable hydrogel matrix prepared for intracorporeal use were investigated. Hydrogel matrices based on polyvinylpyrrolidone and alginate were created using two alginate concentrations, 4%, and 6%, along with three levels of calcium ions for crosslinking: 0.5%,0.6%, and 0.7%.
To assess their potential for medical use, rheological properties, swelling behavior, and degradation profile were evaluated. Furthermore, information on structural and thermal properties was obtained by Scanning Electron Microscopy, Fourier-transform Infrared Spectroscopy, and Thermal Gravimetric Analysis. These studies, which highlight the effect of TBA modification, shed light on the structural integrity, stability, and overall performance of the hydrogel.
Compared to the control group, the results show that the mechanical stability, injectability, swelling, and degradation kinetics of TBA-modified hydrogels are altered. In addition, the microstructure of the hydrogel is changed due to the presence of TBA. No major changes were observed in thermal properties. The findings show that TBA integration adjusts the physicochemical quality of the hydrogels. Further studies will look at in vivo performance and bioactivity evaluations to investigate their clinical significance.

Poly(poly(ethylene glycol) methyl ether methacrylate) (P(PEGMA) is a potential non-immunogenic [1] material for biomedical applications. However, the highly reactive free radical [2] of PEGMA makes control of its polymerisation challenging. In this study, we investigated the synthesis of P(PEGMA) through photoiniferter RAFT (PI-RAFT), a promising approach to synthesise a broad range of (meth)acrylic polymers because of its highly controlled nature. [3] Current studies on the PI-RAFT mechanisms are limited and the effect of the solvent on kinetics has not been reported. The apparent kp values were complicated by the involving RAFT main equilibrium. We calculated the Arrhenius parameters, enthalpy of activation (Δ𝐻‡), and entropy of activation (ΔS‡) for polymerisation in various solvents. Regression analysis was conducted to fit the results with extinction coefficients of the trithiocarbonate chain transfer agent (CTA), solvent physical properties, and solvatochromic scales. The effective collision factor A had a good fitting (adj. R2 = 0.21, p = 0.04) into an exponential regression model of the extinction coefficients, indicating a strong relationship between the rate and excitation of the CTA. Solvent polarity scales, such as Kalmet-Abraham-Taft (KAT) and Catalan parameters, failed to predict kp, Arrhenius parameters, Δ𝐻‡, and ΔS‡. The chain transfer constant Ctr > 1 for all syntheses, indicating relatively good control through degenerative chain transfer with CTA radicals. It was found that Ctr decreased with increasing temperature, a function of the rate of activation being constant, while kp increased with the temperature.

Tissue adhesives play a pivotal role in wound healing and surgical procedures, especially in wet environments where achieving robust adhesion poses significant challenges. Conventional adhesives often show suboptimal performance under fluidic conditions. Drawing inspiration from mussel adhesion strategies, this study utilizes tannic acid (TA) and lignin to develop a bioinspired hydrogel with intrinsic antioxidant, antimicrobial, and pro-regenerative properties.
A mussel-inspired adhesive was developed by integrating glyoxal-modified lignin, polyvinylpyrrolidone (PVP), polyethyleneimine (PEI), and oxidized tannic acid (OTA). Organosolve lignin was first modified with glyoxal, and TA was oxidized using sodium periodate. The quinone-rich OTA enabled dynamic covalent cross-linking with amine groups of PEI, enhancing mechanical strength, self-healing capacity, and wet adhesion. The adhesive underwent comprehensive characterization, including Fourier Transform Infrared (FTIR) Spectroscopy, scanning electron microscopy, rheological evaluations, contact angle measurements, tensile testing, antioxidant analysis, hemolysis, and hemostatic analyses. Rheological data demonstrated that increasing PVP content and TA oxidation significantly shifted the flow point, indicating stronger cohesive forces within the hydrogel network.
Mechanical lap-shear tests, conducted according to ASTM F2255-05, demonstrated substantial adhesion strengths of 5874 ± 748 kPa in dry conditions and 3635 ± 626 kPa in wet conditions. The adhesive also exhibited pronounced antioxidant activity (>95% DPPH inhibition). Hemolysis and hemostatic assays confirmed excellent biocompatibility, low cytotoxicity, and effective hemostasis, contributing to enhanced vascularity. Overall, this multifunctional tissue adhesive offers robust wet adhesion, reduced recovery times, and heightened patient comfort by minimizing infection risks while providing antioxidant protection.

Hydrogel-based drug delivery systems are of interest for their potential use in in vitro and in vivo applications using biopolymer matrices. This study focuses on the development of polymeric hydrogels for the controlled release of procaine, a local anesthetic widely used in clinical applications. Alginate was chosen as the primary component due to its ability to form an ‘egg box’ structure with divalent cations, resulting in a stable hydrogel network[1]. Calcium chloride was used as a crosslinker, allowing the formation of hydrogel matrices with varying degrees of stiffness, directly affecting the procaine release kinetics.
Hydrogel formulations were optimized to achieve effective drug loading, sustained release, and controlled degradation by adjusting calcium ion concentrations, which affect the stiffness and porosity of the hydrogel matrices. Various characterization techniques, including scanning electron microscopy for morphological analysis, Fourier transform infrared spectroscopy for chemical structure, and rheological measurements to evaluate viscoelastic properties, were used to evaluate the structural integrity and performance of the hydrogels.
Additionally, swelling-degradation studies and in vitro drug release experiments were conducted to analyze the hydrogel stability and release kinetics under physiological conditions. The findings indicate that calcium ion concentration significantly affects the structural and functional properties of the hydrogels and affects procaine retention and release. The optimized hydrogel formulations exhibited a sustained and controlled release profile, highlighting their potential for long-term analgesic effects in biomedical applications. These results show the importance of hydrogel design in developing effective localized drug delivery systems, making them promising candidates for therapeutic applications.

Active packages have become a significant center of attention, and especially those based on biodegradable materials, due to their ability to enhance food preservation and extend its shelf life. A suitable base for obtaining such type of packages have turned out to be polymers with natural origin, such as hydroxyl propyl methylcellulose (HPMC). This polymer has great film forming abilities and biodegradability, but its barrier properties and moisture content can be improved in terms of packaging application. Therefore, the present study is focused on developing films via casting method based on pure HPMC and blends between HPMC and Zein. Zein is biopolymer known for its low solubility and hydrophobicity, thus making it suitable partner for polymer blend with HPMC to improve its above mentioned weak points. In order to investigate the potential of these films, some of their most vital properties in terms of potential application as packaging material are established such as: mechanical properties (Strain at break, Young Modulus), barrier properties (water vapor transmission rate and permeability) and morphology. Also, to make them active packaging material, a polyphenolic compound is loaded into them. Additional characterization of wettability and surface free energy, along with radical scavenging ability towards DPPH free radical and thermal behavior and phase state of the films obtained by Differential Scanning Calorimetry prior and after polyphenol addition is done.

Barium sulfate suspensions are common contrast agents for X-ray imaging. Despite their importance, they suffer from low colloidal stability. Herein, we show that polymer/BaSO₄ hybrid nanoparticles can be obtained by surface-induced crystallization of BaSO₄ crystals on polymer functionalized with thiosulfate groups. These groups can be converted to sulfate ions that react with a barium chloride salt, hence leading to nucleation and growth of BaSO₄ crystals. The obtained polymer/BaSO₄ nanoparticles display average diameters of around 151 nm and remain colloidally stable. X-ray diffraction and inductively coupled plasma measurements confirm the presence of BaSO₄ crystals on nanoparticles. The X-ray attenuation coefficient of barium sulfate/polymer hybrid nanoparticles was 121 HU which was significantly larger than the attenuation coefficient of soft tissues.¹

Catheter associated urinary tract infections (CAUTIs) are one of the most prevalent healthcare-associated infections, resulting from biofilm formation on catheter surfaces. Some bacteria related to CAUTIs are urease-producing species which can form crystalline biofilms by increasing urinary pH, and eventually result in encrustation and blockage of catheters.
In this work, we successfully synthesized poly (2-azepane ethyl methacrylate)-b-poly (sulfobetaine methacrylate) (PAEMA-b-PSBMA) as pH-sensitive antifouling polymers and quaternary ammonium salt polymer (PQA) as bactericidal polymers via reversible addition fragmentation chain transfer (RAFT) polymerization, with both polymers containing catechol end groups. The resultant polymers can be tethered to polydimethylsiloxane (PDMS) substrates by a two-step method. In the first step, a coating composed of levodopa/polyethyleneimine (LP) was formed on PDMS by a simple co-deposition process. In the second step, PAEMA-b-PSBMA and PQA were grafted to the LP coating via Schiff base and Michael addition reactions to endow the surfaces with pH-responsive switchable antifouling and antibacterial functionalities. The chemical composition, wettability and thickness of the coatings were characterized by X-ray photoelectron spectroscopy (XPS), ellipsometry and water contact angle (WCA) measurements. The results demonstrated that PAEMA-b-PSBMA and PQA were successfully immobilized on the substrate surfaces.
The facile two-step coating strategy is promising for development of smart antibacterial coating with biocompatibility on urinary catheters to combat CAUTIs.

Cancer remains a leading cause of mortality worldwide(1), driving the need for innovative treatment strategies. Nanoparticle-based systems, particularly iron oxide nanoparticles (IONPs), offer a promising approach due to their dual functionality in diagnosis (e.g., magnetic resonance imaging) and therapy (e.g., hyperthermia, drug delivery)(2). IONPs are valued for their magnetic properties, biocompatibility, and low toxicity(3), which can be further enhanced by polymer surface modifications. Incorporating lithocholic acid, a naturally occurring bile acid with cell-penetrating properties, may improve cellular uptake and therapeutic efficacy.
This study evaluates nano-engineered formulations comprising iron oxide cores with steroid-based polymeric shells functionalized with either folic acid (targeting agent) or doxorubicin (chemotherapeutic drug). We describe the synthesis and characterization of IONPs coated with lithocholic acid-derived polymer layers covalently linked to these functional agents. Cytotoxicity was assessed against normal and cancerous cell lines using MTT and Neutral Red assays. Additionally, transepithelial electrical resistance, caspase 8 and 9 expression, and the impact on cytochrome P450 enzyme activity were evaluated in cancer cells.
The results demonstrate that the synthesized nanoparticles selectively target cancer cells, inducing apoptosis through caspase activation while sparing normal cells. These findings highlight the potential of these formulations as effective, biocompatible systems for targeted cancer therapy.

Acknowledgment: NCN OPUS 18 (2019/35/B/ST5/03391). Analyses were conducted at the Centre BioNanoTechno, University of Bialystok.

In Europe, acute or chronic wounds affect an estimated 1.5-2 million people, whereby
2-4 % of total healthcare expenditure is spend on wound care. Occurrence of complications such as infections with e.g. Escherichia coli lead not only to increasing costs but also to antibiotic resistances and infection-attributable deaths. Wound dressings prepared from biopolymers such as alginate, chitosan, collagen, cellulose and hyaluronic acid are available in various forms. Biopolymers are known for biodegradability, non-toxicity, biocompatibility and their ability to mimic the native extracellular matrix. Alginate has a high capacity to absorb wound exudates, chitosan shows hemostatic activity, and hyaluronic acid has anti-inflammatory activity. Nevertheless, they lack of antimicrobial activity and tissue adhesion.
In order to overcome these boundaries, it can be beneficial to synthesize a biopolymer comprising antimicrobial functionalities named maleimide on its polymeric backbone. Maleimide - acting as a Michael acceptor - is known for its ability to form stable thioether linkages with thiol groups, which can be found in cysteine containing amino acids of mucosa and skin. Furthermore, maleimide shows antibacterial and antifungal activity based on the same principle by covalently binding to bacterial and fungal enzymes containing cysteine and thereby inhibiting microbial growth.

Redox label–conjugated aptamers are widely employed in electrochemical biosensors. To enhance their sensitivity, multiple redox labels must be attached to each aptamer. Here, N3-terminated polylysine was used as a poly-linker to conjugate multiple redox labels onto an aptamer probe. We then applied these conjugates in two electrochemical biosensors: (i) a wash-free, sandwich-type thrombin biosensor and (ii) a biosensor based on a minimal aptamer–aptamer sandwich. The detection mechanisms rely on (i) redox label–catalyzed oxidation of a reductant, (ii) conjugation of multiple redox labels per probe using the poly-linker, (iii) low nonspecific adsorption of the conjugated poly-linker due to the uncharged nature of the reduced redox labels, and (iv) facile direct electron transfer facilitated by the long, flexible poly-linker and spacer DNA. Using amine-reactive phenazine ethosulfate as the redox label and NADH as the reductant, we achieved approximately 11 redox labels per probe. This design, combined with rapid catalytic NADH oxidation, offers strong signal amplification for sensitive detection.

The electrospinning fabrication of multifunctional nanomaterials has garnered significant attention due to their extensive applications in the biological, medical, and food industries. In this study, nanofibers with superior antibacterial properties were developed by incorporating Europium hydroxide nanorods (Eu(OH)₃) and reduced graphene oxide (RGO) into a poly(ethylene oxide) (PEO) polymer matrix via electrospinning. Uniform Eu(OH)₃/RGO nanocomposites were synthesized rapidly, one-step microwave-assisted, and dispersed into a PEO solution to fabricate the nanofibers.
The prepared Eu(OH)₃/RGO/PEO nanofibers were systematically characterized using X-ray diffraction (XRD), Raman spectroscopy, and Fourier-transform infrared spectroscopy (FTIR) to confirm the successful reduction of graphene oxide and the formation of the Eu(OH)₃ phase (JCPDS#83-2305). Scanning electron microscopy (SEM) revealed that the optimal morphology of nanofibers was achieved at an electrospinning voltage of 24 kV and a flow rate of 1 mL/h. Antibacterial activity against E. coli was evaluated using minimum inhibitory concentration (MIC), colony counting, inhibition zone diameter, and optical density (OD) measurements. The results demonstrated that Eu(OH)₃/RGO/PEO nanofibers exhibited outstanding bactericidal performance, completely reducing viable bacterial counts at 0.1 mg/mL concentration.
This novel Eu(OH)₃/RGO/PEO nanocomposite exhibited excellent antibacterial efficacy and holds significant potential for biomedical devices, food packaging, and antimicrobial coatings applications. The study highlights the synergistic effect of Eu(OH)₃ and RGO in enhancing antibacterial properties. It paves the way for developing advanced polymer-based materials for biological, medical, and food-related applications.

Bioactive electrospun scaffolds with enhanced biological and mechanical properties were developed using polycaprolactone (PCL) blended with starch and reinforced with bioactive nanoparticles (calcium oxide (CaO) and bioglass (BG)). PCL was chosen for its biocompatibility and mechanical properties [1], starch for its biodegradability and hydrophilicity [2], and nanoparticles for their potential to induce biomineralization [3,4]. The addition of CaO nanoparticles increased the average fiber diameter to approximately 1.2 µm, while BG-reinforced fibers exhibited diameters ranging from 311 to 438 nm. Both scaffold types demonstrated high porosity, pore interconnectivity, and significant improvements in water absorption. Enhanced degradation rates were observed, with mass losses of 60% and 37% for PCL/Starch/CaO and PCL/Starch/BG scaffolds, respectively. Thermal analysis revealed starch's role in increasing crystallinity, while BG reduced it, creating optimal structural properties. Mechanical analysis revealed opposing trends: CaO increased Young’s modulus by 60%, while BG reduced it by 52%. Both formulations exhibited biomineralization capacity, forming hydroxyapatite on their surfaces after immersion in simulated body fluid. Biological evaluations demonstrated excellent cell adhesion and viability for preosteoblastic MC3T3-E1 and MG-63 osteoblast-like cells. In vivo studies using a subdermal Wistar rat model confirmed superior biocompatibility and bioresorbability, with enhanced healing and reabsorption compared to neat PCL. These findings highlight the synergistic effects of combining starch and bioactive nanoparticles in electrospun scaffolds, making PCL/Starch/CaO and PCL/Starch/BG composites promising candidates for bone tissue engineering applications.

Nanofibers have garnered significant attention due to their excellent antibacterial properties and low cytotoxicity. Chitosan (CS), known for its biocompatibility, non-toxicity, and inherent antimicrobial activity, has been widely utilized in medicine and food-related applications. However, the protonation of chitosan in acidic solvents hinders its electrospinning process. To overcome this challenge, poly(ethylene oxide) (PEO) was introduced to improve the spinnability of chitosan. This study successfully fabricated CS/PEO nanofibers by optimizing polymer concentration and tuning electrospinning parameters such as voltage and flow rate. The nanofibers were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FT-IR). Antimicrobial properties were evaluated using the colony counting method. The experimental results revealed that the optimal electrospinning conditions were achieved at a voltage of 20 kV and a flow rate of 1 mL/h. The morphology analysis confirmed the formation of uniform, defect-free nanofibers.
Additionally, incorporating chitosan significantly enhanced the antimicrobial properties, with higher chitosan weight percentages correlating positively with increased antibacterial activity. Under the optimized conditions, the CS/PEO nanofibers achieved an outstanding antibacterial efficiency of 97%. This remarkable performance is attributed to the synergistic effect of chitosan's antimicrobial activity and the structural integrity provided by PEO. These findings suggest that CS/PEO nanofibers hold significant potential for biomedical devices and food preservation applications.