The urgent need to replace fossil resource-based products is considerably increasing in the past few years, resulting in the search for more sustainable materials, with the aim of reducing the wastes from polymer pollution, solving economic and environmental issues. This is even more relevant in industrial fields, where toxic compounds are the basis of their polymeric formulations. Herein is reported the most relevant advances of epoxy resins (ERs) in the past decade, with great emphasis on the replacement of bisphenol A (BPA), leading to the production of renewable-based ERs with good properties. The synthesis of ERs based on renewable sources, such as vegetable oils, phenolic compounds, sugars and the outcome in the material’s structure is explored within this review. Emphasis is also given to the use of new biobased curing agents and biofillers to enhance the biocharacter of the ERs.

Polyurethanes (PUs) are extremely versatile materials used across different industries. Traditionally, they are synthesized by reacting polyols and isocyanates, both of which are petroleum-derived reagents. In response to the demand for more eco-friendly materials, research has increasingly focused on developing new routes for PU synthesis using renewable feedstocks. While substituting isocyanates remains a greater challenge, replacing fossil-based polyols with bio-based alternatives is now a promising strategy. This review explores the main natural sources and their transformations into bio-polyols, the incorporation of bio-fillers into PU formulations, and the production of non-isocyanate polyurethanes (NIPUs). Additionally, the study summarizes the growing body of research that has reported successful outcomes using bio-polyols in PU foams for distinct applications.

Recently, the biomedical scientists who are working in the skin regeneration area have proposed asymmetric membranes as ideal wound dressings, since they are able to reproduce both layers of skin and improve the healing process as well as make it less painful. Herein, an electrospinning technique was used to produce new asymmetric membranes. The protective layer was composed of a blending solution between polycaprolactone and polylactic acid, whereas the underlying layer was comprised of methacrylated gelatin and chitosan. The chemical/physical properties, the in vitro hemo- and biocompatibility of the nanofibrous membranes were evaluated. The results obtained reveal that the produced membranes exhibited a wettability able to provide a moist environment at wound site. Moreover, the membranes’ hemocompatibility and fibroblast cell adhesion, spreading and proliferation at the surface of the membranes were also noticed in the in vitro assays. Such results highlight the suitability of these asymmetric membranes for wound dressing applications.

The preparation of photocrosslinkable bioadhesives synthesized from oligomers of lactic acid and polycaprolactone (PCL), both functionalized with 2-isocyanoethyl acrylate (AOI), were studied. The obtained modified macromers of LA-AOI (mLA) and PCL-AOI (mCL) were chemically characterized by ¹H NMR and used to formulate polymeric blends with different mass proportions, 1:1, 1:2 and 2:1, respectively. Subsequently, the produced blends were crosslinked, considering two UV irradiation times: 30 and 120 s. After their production, the thermal and mechanical properties of bioadhesives were assessed, where upon the rheology, gel content, hydrolytic degradation and dynamic contact angles were determined. Furthermore, the cytotoxic profile of bioadhesives was evaluated in contact with human dermal fibroblasts cells, whereas their antibacterial effect was studied monitoring Escherichia coli and S. aureus growth. Overall, flexible and resistant films were obtained, presenting promising features to be used as surgical bioadhesives.

Sugar-based polyurethane (PU) foams represent an important advancement in structured materials offering a more sustainable alternative to traditional PU foams derived from petro-based polyols. These PU foams can hold particular importance in fields such as construction, packaging, biomedical materials, and medical devices. Hitherto, the development relies on a trial-and-error basis or, at most, by changing one-factor-at-a-time (OFAT). Unfortunately, these methods are inefficient and prone to miss the intended goals. In this study, we apply a Quality by Design (QbD) strategy, integrating systematic experimental design and data-driven approaches, to optimize sugar-based PU foam formulations for integration into a pathogen-monitoring device and identify key factors affecting their properties. The effects of surfactant, water, catalyst, chain extender, and isocyanate concentrations were evaluated using statistical design of experiments (DoE), and the amount of water was identified as the most influential factor. An optimized formulation was obtained with 0.58% (w/w) water, 5.69% (w/w) surfactant, and 34.26% (w/w) toluene diisocyanate (TDI), with butanediol excluded due to its minor impact on foam’s performance and the water being the most impactful factor. This optimized formulation was synthesized and validated with the final material being able to absorb liquids, support capillary flow, and maintain physical integrity and glucose content. This approach enabled the tailored development of sugar-based PU foams to meet the specific application requirements.