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A family of polymer substrates which consists of a vinyl backbone chain with the side groups -COO(CH 2 ) x CH 3 , with x ¼ 0, 1, 3, 5 was prepared. Substrates with decreasing stiffness, characterised by the elastic modulus at 37 C, and similar chemical groups were obtained. Firstly, we have investigated whether these minute variations in polymer chemistry lead to differences in fibronectin (FN) adsorption: the same FN density was obtained on every substrate (450 ng cm À2 ) but the supramolecular organisation of the protein at the material interface, as obtained with AFM, was different for x ¼ 0 and the other surfaces (x ¼ 1, 3, 5). Consequently, this allows one to use a set of substrates (x ¼ 1, 3, 5) to investigate the effect of substrate stiffness on cell behavior as the unique physical parameter, i.e. after ruling out any influence of the length of the side group on protein conformation. Moreover, the importance of investigating the intermediate layer of proteins at the cellmaterial interface is stressed: the effect of x ¼ 0 and x ¼ 1 on cell behavior cannot be ascribed to the different stiffness of the substrate anymore, since the biological activity of the protein on the material surface was also different. Afterwards, initial cellular interaction was investigated using MC3T3-E1 osteoblasts-like cells and focusing on actin cytoskeleton development, focal adhesion formation and the ability of cells to reorganize the adsorbed FN layer on the different substrates. Image analysis was used to quantify the frequency distribution of the focal plaques, which revealed broader distributions on the stiffer substrates, with formation of larger focal plaques revealing that cells exert higher forces on stiffer substrates.

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Some biomaterial scaffolds can positively interfere with tissue regeneration and are being developed to successfully repair the tissue function. The possibility of using epithelial cells combined with biomaterials appears to be a new option as therapeutic application. This combination emerges as a possibility for patients with Mayer–Rokitansky–Kuster–Hauser syndrome which requires vaginal repair and can be performed with tissue-engineered solution containing cells and biomaterials. It is expected that tissue-engineered solution containing cells and biomaterials would promote tissue repair in a more efficient, modern, and safe way. This study tested the efficiency of tissue-engineered solution containing human malignant melanoma cell line (HMV-II) and different biomaterials, including Cellprene®, Membracel®, and poly lactic-co-glycolic acid/epoxidized polyisoprene. The cells adhered better on poly lactic-co-glycolic acid/epoxidized polyisoprene, and it was found that tissue-engineered solution may also contain mesenchymal stem cells cultivated on poly lactic-co-glycolic acid/epoxidized polyisoprene. Histological, immunofluorescence, and scanning electron microscopy analyses were performed. These initial in vitro results suggest that tissue-engineered solution containing cells and poly lactic-co-glycolic acid/epoxidized polyisoprene is a potential for tissue reconstruction.

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The incorporation of drugs and bioactive compounds in the natural rubber latex (NRL) matrix has been an alternative for the development of transdermal release membranes. Ibuprofen (IBF) is known to be used to treat inflammatory diseases, but when administered orally, high concentrations can cause some adverse problems. In this work, the incorporation of IBF in the NRL membranes was evaluated by physical-chemical, in vitro permeation, hemocompatibility and molecular modeling assays. In addition, the in vitro release profile of IBF in acid and basic media was analyzed during 96 h. The IBF-NRL membrane exhibited the absence of intermolecular bonding that could hinder drug release and presented compatible mechanical properties for applications as a cutaneous adhesive (0.58 and 1.12 MPa to Young’s modulus and rupture tension, respectively). The IBF-NRL system did not present a significant hemolysis degree (1.67%) within 24 h. The release test indicated that in the first hours of the study, 48.5% IBF was released at basic pH and 22.5% at acidic pH, which is characteristic of a burst effect. Then, a stable release profile was observed until the end of the assay, with total IBF release of 60% in alkaline medium and 50% in acidic medium. The drug permeation results indicated that the IBF-NRL membranes can be used for the local skin treatment with permeation of 3.11% of IBF. Dynamic Molecular simulations indicated a pronounced electric dipole in the ionized form of IBF, which suggests a more effective interaction with water, explaining the efficient drug release in alkaline solutions. In general, the results demonstrate that the IBF-NRL membrane has great potential for a new adhesive that can be used for the treatment of inflammatory processes and injuries.

Three‐dimensional (3D) printing is a rapidly growing technology and plays an emerging role in several biomedical applications. Polylactic acid (PLA) is one of the most common materials in 3D printing, however, it is chemically inert due to the absence of reactive side chain groups. In this context, in this work, the PLA scaffolds with two different geometries were produced and coated with natural rubber latex (NRL) extracted from the rubber tree Hevea brasiliensis. NRL presents bioactive substances that are related to its biological properties. The results revealed scaffolds with interconnected pores and pores sizes from 600 to 1300 μm. The NRL coatings caused a decrease in pore size. Infrared spectra showed that 2 NRL layers were more efficient in coverage. Compressive strength values obtained are in agreement with the spongy bones value (22–24 MPa for crossbar and 20–22 MPa for roundbar cube). Finally, the hemolytic activity of the PLA scaffold was 3%, while the scaffolds coated with 1 and 2 NRL layers presented values of 0%, indicating a potential use in biomedical applications due to the absence of hemolytic effects.

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