Copolímeros casca-núcleo de poli(acrilato de butila) (núcleo) e poliestireno (casca) foram sintetizados por meio de polimerização em emulsão, conduzida em duas etapas. A adição de ácido itacônico como monômero funcional na polimerização do núcleo foi realizada para verificar seu efeito sobre suas propriedades mecânicas e de processamento. Os copolímeros foram caracterizados por espalhamento dinâmico de luz (DLS), microscopia eletrônica de transmissão (MET), cromatografia de exclusão por tamanho (SEC), espectrometria na região do infravermelho (FTIR) e calorimetria diferencial por varredura (DSC). A incorporação do monômero funcional foi confirmada por DSC e quantificada por titulação. A proporção de poli(acrilato de butila) e poliestireno influenciou diretamente o processamento e as propriedades mecânicas do polímero. Os copolímeros com teores de poliestireno acima de 50% foram processados por compressão e extrusão a temperatura ambiente, apresentando comportamento baroplástico. A presença do monômero funcional não alterou o processamento do polímero e melhorou significativamente sua resistência à tração, aumentando sua tenacidade

Cellulose is the most abundant renewable polymer on Earth and can be obtained from several different sources, such as trees, grass, or biomass residues. However, one of the issues is that not all the fractionation processes are eco-friendly and are essentially based on cooking the lignocellulose feedstock in a harsh chemical mixture, such as NaOH + Na2S, and water, to break loose fibers. In the last few years, new sustainable fractionation processes have been developed that enable the obtaining of cellulose fibers in a more eco-friendly way. As a raw material, cellulose’s use is widely known and established in many areas. Additionally, its products/derivatives are recognized to have a far better environmental impact than fossil-based materials. Examples are textiles and packaging, where forest-based fibers may contribute to renewable and biodegradable substitutes for common synthetic materials and plastics. In this review, some of the main structural characteristics and properties of cellulose, recent green extraction methods/strategies, chemical modification, and applications of cellulose derivatives are discussed.

A smart asphalt mixture holds new capabilities different from the original ones or can react to a stimulus. These capabilities can be categorized based on smartness or function: smartness, mechanical, electrical, optical, energy harvesting, electromagnetic wave/radiation shielding/absorbing, and water related. The most important capabilities applied to asphalt mixtures are the photocatalytic, self-cleaning, self-healing, superhydrophobic, thermochromic, deicing/anti-icing, and latent heat thermal energy storage abilities. This research deals with a bibliometric review of the peer-reviewed journal articles published on the Scopus database, with the strings of terms related to these capabilities and asphalt or bitum in their titles, abstracts, and keywords. The review analysis highlighted the increasing number of accumulated publications, confirming the relevance of this research topic in recent years. The capability most often referred to was self-healing. The study showed that China was the most productive country. Research articles were mostly published in the journal Construction and Building Materials. Several techniques and methods are being developed regarding smart asphalt mixtures; for that reason, this research work aims to evaluate the literature under a bibliometric analysis.

In recent decades, there has been a growing interest within scientific and medical communities in the development of new biomedical materials for the effective and safe treatment of acute wounds. Surgical adhesives have emerged as a promising alternative to conventional methods such as sutures, staples, and adhesive strips, offering less invasive and potentially safer applications. However, these traditional techniques present limitations, including the induction of additional tissue trauma. Surgical adhesives enable efficient approximation of tissue edges, promoting wound healing while reducing trauma to the surrounding tissues, which translates into improved aesthetic outcomes and a reduced need for anesthesia. Furthermore, their potential biodegradability often eliminates the need for postoperative removal.Currently, surgical adhesives of natural, synthetic, and semi-synthetic origin are available. Nevertheless, the release of toxic by-products, limited mechanical performance, and the risk of disease transmission restrict some of their clinical applications. A promising approach involves the development of photo-crosslinkable adhesives activated by ultraviolet (UV) radiation, due to their potential to overcome the drawbacks associated with conventional closure methods and improve overall clinical outcomes.The present work aimed to develop photo-crosslinkable surgical adhesives synthesized from polyethylene glycol (PEG) functionalized with 2-isocyanatoethyl acrylate (AOI), for potential use as tissue adhesives. The synthesized polymers were subsequently crosslinked using two different UV irradiation times (30 and 120 s) in order to evaluate the influence of the crosslinking period on the final properties of the adhesives.Chemical characterization was carried out by ATR-FTIR and 1H-NMR spectroscopy, confirming the successful functionalization of PEG with AOI. The thermal properties were assessed by thermogravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMTA), allowing the determination of thermal stability, glass transition temperature, and viscoelastic behavior. The adhesives exhibited glass transition temperatures below 0 °C, indicating flexible materials at both room and physiological temperatures, while TGA results demonstrated adequate thermal stability for biomedical applications.Surface property evaluation revealed surface energy and wettability values close to those of biological tissues and blood, indicating good affinity with humid physiological environments. Dynamic contact angle measurements confirmed the hydrophilic nature of the adhesives, favoring interactions with tissues and biological fluids. Gel fraction analysisvievidenced high degrees of crosslinking, with higher values observed for longer UV irradiation times, which was reflected in the structural stability of the materials.Water uptake studies revealed significant swelling behavior (40 %), typical of PEG-based systems, although inversely dependent on the degree of crosslinking. Hydrolytic degradation assays in phosphate-buffered saline (PBS) showed a progressive and controlled mass loss, being less pronounced in adhesives with higher crosslinking density. In vitro biocompatibility assays performed with normal human dermal fibroblasts demonstrated the absence of significant cytotoxicity, with the PA30 adhesive showing superior cytocompatibility, associated with its lower crosslinking density.Overall, the results indicate that PEG functionalization with AOI represents a promising strategy for the development of photo-crosslinkable surgical adhesives. The PA30 formulation emerged as the most promising one, as it combines an adequate degree of crosslinking with favorable mechanical and biological responses for the desired application, despite requiring a shorter crosslinking time. This work contributes to the advancement of knowledge in the area of adhesive biomaterials, opening perspectives for the development of more effective and less invasive clinical solutions for tissue repair.

This doctoral thesis addresses the design, synthesis, and characterization of UV-curable polymeric biomaterials for rapid and minimally invasive tissue repair. The central objective was to develop photocrosslinkable, cytocompatible, and biodegradable formulations that can function as surgical adhesives, offering a viable alternative to conventional closure techniques such as sutures and staples. By exploiting on-demand UV-induced crosslinking, the materials investigated in this work aim to combine fast curing, controlled degradation, and suitable mechanical performance, while minimizing additional tissue trauma and improving patient comfort.The research follows a multidisciplinary strategy that integrates polymer chemistry, materials science, and biological evaluation. Several families of prepolymers and macromers were synthesized and systematically studied, including: (i) lactic-acid- and polycaprolactone-based oligomers functionalized with vinylic isocyanates, (ii) photocurable blends combining hydrophilic and hydrophobic macromers, (iii) unsaturated polyesters derived from renewable monomers such as itaconic acid and 1,4-butanediol, and (iv) PEG-based systems functionalized with 2-isocyanatoethyl acrylate. Functionalization strategies were designed to introduce carbon–carbon double bonds and, in some cases, urethane linkages and residual isocyanate groups, enabling UV-induced network formation and potential covalent or secondary interactions with tissue.All materials were characterized using a consistent set of techniques, including structural (ATR-FTIR, ¹H NMR), thermal (TGA, DSC, DMTA), rheological, and surface analyses, as well as physicochemical assays (gel content, swelling, hydrolytic degradation in PBS, dynamic contact angles, and surface energy). Cytocompatibility was assessed using human dermal fibroblasts, while selected systems were further evaluated for hemocompatibility and antibacterial activity against Escherichia coli and Staphylococcus aureus. Across the different families, UV irradiation times between 30 s and 5 min were sufficient to obtain homogeneous, transparent, and flexible films with high gel contents and glass transition temperatures well below physiological temperature, ensuring elastomeric behavior in use. Rheological measurements confirmed low viscosities and predominantly Newtonian behavior at room and physiological temperatures, supporting ease of in situ application by spreading, injection, or spraying.The results demonstrate that network architecture and composition can be tuned to modulate swelling, degradation, and biological response. Lactic-acid-rich systems (e.g., crossLA and mLA-rich blends) exhibited higher swelling and faster hydrolytic degradation, together with intrinsic antibacterial activity attributed to lactic acid oligomers and enhanced hydrophilicity. PCL-rich and PCL–castor-oil systems showed lower degradation and higher stability, more suited to applications requiring prolonged mechanical support. Biobased itaconate polyesters (IB1/IB2) confirmed that fully solvent- and catalyst-free routes can yield photocrosslinkable materials with controlled degradation and cytocompatibility. PEG–AOI-based adhesives (PA30/PA120) combined very low viscosity, fast curing, hydrophilic surfaces, and favorable surface energy for adhesion to skin and moist tissues, with PA30 in particular displaying superior cytocompatibility.To integrate the extensive experimental dataset and support the selection of the most promising candidates, a Multi-Criteria Decision-Making framework based on Multi-Attribute Value Theory and Taguchi loss functions was implemented. Curing time, hydrolytic degradation, and cell viability were used as key performance indicators, with antibacterial activity considered in a complementary analysis. This systematic ranking highlighted formulations such as crossLA-30s, crossLA-2min, IB2-1, and PA30 as leading candidates for specific clinical contexts, distinguishing between rapidly resorbable external wound adhesives and more persistent internal sealants.Overall, this thesis demonstrates that UV-curable polymeric systems can be tailored to display suitable physicochemical and biological profiles for tissue adhesive applications. The work highlights how monomer composition, type and degree of functionalization, and UV-curing conditions influence network structure, degradation behavior and cytocompatibility. The materials and design criteria defined here provide a basis for the development of next-generation surgical adhesives and support future studies, including more detailed mechanical and adhesion testing, extended hemocompatibility and antibacterial assessment, and in vivo evaluation in relevant wound-healing models.

Abstract Halloysite nanotubes (HNTs) are aluminosilicate nanoclay mineral which have a hollow tubular structure and occurs naturally. They are biocompatible and viable carrier for inclusion of biologically active molecules due to the empty space inside the tubular structure. In this article, the HNTs main characteristics, and the HNTs-polymeric nanocomposite formation and their potential application as improvement of the mechanical performance of polymers and entrapment of hydrophilic and lipophilic substances are summarized. Recent works covering the increment of HNTs-polymeric nanocomposites and presenting promising employment of these systems as nanosized carrier, being suitable for pharmaceutical and biomedical applications, based on earlier evidence in literature of its nature to sustain the release of loaded drugs, presenting low cytotoxicity, and providing evidence for controlled drug delivery are reviewed.

Abstract Fe3O4 nanoparticles were synthesized and functionalized with (3-aminopropyl) trimethoxysilane (APTMS) and chitosan, forming Fe3O4-NH2 and Fe3O4-NH2-chitosan nanoparticles. The Fe3O4 nanoparticles were synthesized by a co-precipitation method and functionalization was performed in further stages. The nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), zeta potential, and transmission electron microscopy (TEM). The results of XRD showed that magnetite did not experience an oxidation reaction. The functionalization of the surface of Fe3O4 nanoparticles was confirmed by FTIR and zeta potential measurements. The TEM results showed a thin layer around Fe3O4 nanoparticles due to the functionalization with the APTMS. The later functionalization by chitosan contributed to the agglomeration of nanoparticles. Functionalization provided the nanoparticles better colloidal stability mainly for a pH below 7 and this improvement was related to the protection and new functional groups from the APTMS and chitosan.

The 2,2'-bipyridine has been entitled as the most widely used ligand. Nowadays there is a large variety of known molecules comprising at least two 2,2'-bipyridine units and the number of applications in many areas such as catalysis, new materials, optoeletronics and electrochemistry have increased very much in the past decades. Nevertheless, there is no article that gives an overview of the main synthetic methods for obtaining the substituted 2,2'-bipyridines, generally non available. This article presents a synthetic discussion about the three different methods (coupling reaction, ciclo-functionalization and functionalization of the heteroaromatic rings of 2,2'-bipyridine) for preparing these heterocyclic compounds and also provides a practical and fundamental guide, for obtaining more than eighty different symmetric and unsymmetrical substituted 2,2'-bipyridines, shown in a table with the corresponding references.

The immobilization of Burkholderia cepacia lipase (BCL) on pristine or functionalized multi-walled carbon nanotubes (MWCNTs) was studied in the resolution of (RS)-1-phenylethanol. For the functionalization, three treatments were used, these being in H2SO4/HNO3 (acid, MWCNTs-A), KOH (basic, MWCNTs-B) or in H2O2 (oxidizing agent, MWCNTs-O). It was found that the pristine or functionalized BCL/MWCNTs resulted in a 3-fold improvement in the conversion and in a 5-fold improvement in ees (enantiomeric excess of the substrate), when compared with free BCL under the same reaction conditions. This pristine or functionalized BCL/MWCNTs system could be reused for up to 8 times without significant decrease in the catalytic efficiency. Under the optimum conditions (pH of immobilization 6.0, 45 ºC and 25 mg/5 mg pristine or functionalized BCL/MWCNTs), the best results were obtained using BCL immobilized on MWCNTs-A. The simple process of physical adsorption of BCL onto MWCNTs-A has improved the catalytic efficiency when compared with free BCL and an increase in the stability was confirmed by thermogravimetric analysis (TGA).