Three-dimensional printing (3DP) technologies are characterized as a set of innovative manufacturing techniques that allow for the creation of complex and/or personalized three-dimensional physical objects on the work surface of a 3D printing machine (based on the computer-aided design (CAD) project designs of these parts). Three-dimensional printing techniques are widely used in various areas of knowledge, such as education, engineering, and biomedicine. Polymeric materials are widely used for these applications, mainly due to their desirable workability during part manufacturing, compatibility with other chemical materials, the wide range of polymers with different physical and chemical characteristics, and the possibility for recycling. The development of polymeric drug delivery systems (DDSs) by 3D printing is currently an active field of research, both in academia and industry, given the potential of this technique for medical purposes. In this context, this work reviews potential polymers for the production of drug delivery systems via 3D printing techniques. The demonstrations of the main 3DP techniques used for drug delivery applications include their working principles and advantages and how the technologies develop the final product. In addition, potential synthetic and natural polymers that are currently used in 3DP drug delivery devices are presented and discussed based on recent scientific studies.

Metal oxide nanocomposites (MON) have gained significant attention in the literature for the possibility of improving the optical and electronic properties of the hybrid material, compared to its pristine constituent oxides. These superior properties have been observed for TiO₂ — based MON, which exhibit improved structural stability and photoactivity in environmental decontamination processes. In addition, the use of polymer membrane-supported MON is preferable to prevent further aggregation of particles, increase the surface area of the semiconductor in contact with the contaminant, and enable material reuse without considerable efficiency loss. In this work, $\mathrm{V}$⁵⁺-doped ${\mathrm{TiO}}_2/{\mathrm{WO}}_3 \mathrm{MON}$ nanostructures were prepared by the sintering process at 500 °C and supported in electrospun fiber membranes for application as photocatalyst devices. Microstructural characterization of the samples was performed by XRD, SEM, EDS, Raman, and DSC techniques. The reflectance spectra showed that the bandgap of the MON was progressively decreased (3.20 to 2.11 eV) with the V⁵⁺ ions doping level increase. The fiber-supported MON showed photoactivity for rhodamine B dye degradation using visible light. In addition, the highest photodegradation efficiency was noted for the systems with 5 wt% vanadium oxide dispersed in the fibers (92% dye degradation in 120 min of exposure to the light source), with recyclability of the composite material for use in new photocatalysis cycles. The best results are directly related to the microstructure, lower bandgap and aggregation of metal oxide nanocomposite in the electrospun membrane, compared to the support-free MON.

The importance of the Eudragit^® E100 copolymer (E100) is recognized in the pharmaceutical industry as a pH-dependent coating material in conventional oral administration dosage applications, where a modified release profile is required. On the other hand, its arrangement for 3D printing of cylindrical-shaped filaments containing drugs (to produce customized pharmaceuticals), is still scarce in the literature, and is currently an open field of research. One of the main challenges involves the manufacture of filaments that are flexible and functional, as their cylindrical shape (which is necessary for its use on FDM 3D printers) significantly increases the material’s fragility. Thus, the objective of this work was to prepare and characterize E100/Hesperidin (Hsp) filaments, and to study in vitro dissolution from Hsp active molecules of this unconventional polymeric matrix. The hybrid filaments were produced using a surface chemical treatment of the material resulting from a hot-melt extrusion process. The microstructural characterization of the filaments was performed using SEM, XRD, FTIR and ATR. The thermal analysis of the materials was performed using DSC, and the mechanical resistance was analyzed using flexural testing. The in vitro release profiles of the filament-arranged drug were evaluated in solutions of simulated gastro and intestinal fluids.

The process of manufacturing drug delivery systems (DDSs) by fused deposition modeling (FDM) with 3D printing requires the availability of a polymeric filament containing the drug of interest. This filament is fused in the printer heating system and used to print polymer/drug volumetric parts. Polymers with pH-dependent solubility are widely known in the literature for their controlled release and drug dissolution-enhancing properties, biocompatibility, and variety of release profiles. Given these characteristics, the study of pH-responsive 3D printing filaments appears as a potential alternative for the development of new 3D printing functional materials for healthcare area applications. In this sense, this work aimed at the preparation and characterization of pH-dependent filaments of the Eudragit E 100 copolymer (E100) containing the model drug Amlodipine (Aml) for potential application in the manufacturing of DDSs by 3D printing. The E100/Aml filaments with two distinct drug concentrations were produced by hot-melt extrusion at 105 °C. The posterior chemical protonation treatment of the filaments for 60 min provided a significant improvement in their flexibility. Microstructural analysis (SEM, XRD, FTIR, and DLS) and thermal studies by DSC proved the feasibility of producing the filaments by hot-melt extrusion without the degradation of their constituent materials. The in vitro dissolution profiles of the E100/Aml samples were evaluated in simulated gastric and intestinal fluids. The facilitated solubility of the polymer in an acidic medium (pH = 1.2) was preserved in the filament form, with rapid and reproducible drug release from the polymer matrix. The saturation of the drug concentration in the medium occurred after 30 min of testing for E100/Aml models. A customized 3D part with geometry and fill control was also printed from E100/Aml filaments as proof of concept.

Poly (methyl methacrylate) is a polymer widely used in various biomedical applications. In orthopedics, this polymer may be used as a structural reinforcement in fracture, aiding bone regeneration. To avoid fracture contamination, surgeons may add a certain homogeneously amount of antimicrobial to the Poly (methyl methacrylate). To prevent thermal necrosis during polymerization, which can reach up to 100° C, cooling techniques are used, to ensure the cells integrity during the process. Despite the great importance of Poly (methyl methacrylate) as a biomaterial, there is still a lack of information on the mechanical properties of this polymer, especially when there is modifications on Poly (methyl methacrylate) composition and its preparation temperature. This work aims to evaluate the influence of the addition of Gentamicin Sulfate and application of cooling technique on the mechanical behavior of Poly (methyl methacrylate) in three commercial types. For this, the mechanical tests of compression, bending and torsion were performed. With these tests it was found that, despite the reduction of the mechanical resistance of Poly (methyl methacrylate) with the cooling technique and antimicrobial addition, the polymer can still be safely used as bone cement. DOI:https://doi.org/10.56238/uniknowindevolp-133

Anais do Congresso Internacional de Engenharia Mecânica e Industrial (2764-4294) - Análise Da Influência Do Sulfato De Gentamicina E Técnica De Resfriamento Nas Propriedades Mecânicas Do Poli(Metacrilato De Metila)