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Gavinho, Sílvia R., Mariana Castro Soares, João Borges Borges, Jorge Carvalho Silva, Isabel Sá Nogueira, and Manuel P. Graça. "Preparation and Characterization of Zinc and Magnesium Doped Bioglasses." Nanoscience and Nanotechnology in Security and Protection against CBRN Threats (2020): 465-475. AbstractWebsite

Peri-implantitis is an infectious disease that affects about one of five patients who receive a dental implant within 5 years after the surgery. To minimize this reaction the development of new biomaterials with antibacterial action is needed that can be used as a coating material in orthodontic implants. In addition, these biomaterials can be doped with several ions, which add specific properties that may act at the cellular level, such as increasing the angiogenesis efficiency. In this work, 45S5 Bioglass® has been used as the base material because it presents higher bioactivity compared to other biomaterials. To add antibacterial function and increase positive effects on bone metabolism, zinc and magnesium ions were introduced in the glass network. The main objective was the synthesis of the 45S5 glass by melt-quenching and study the biological performance as function of the zinc and magnesium concentrations. The structural and biological properties of the prepared samples are discussed.

Godinho, Maria Helena, João Paulo Borges, João Carlos Bordado, Maria Teresa Cidade, and Assis Farinha Martins. "Preparation and liquid-crystalline properties of toluene-4-sulphonyl urethane of hydroxypropylcellulose." Liquid Crystals 14 (1993): 653-659. AbstractWebsite

A novel liquid-crystalline polymer, the toluene-4-sulphonyl urethane of hydroxypropylcellulose (TSUHPC), was prepared through chemical modification of hydroxypropylcellulose (HPC) of Mw = 60000 g mol−1. The resulting polymer was characterized by infrared spectroscopy, differential scanning calorimetry (DSC) and polarizing microscopy. It was found that thermotropic liquid crystal phases are formed between about 60°C and 110°C. Concentrated solutions of TSUHPC in acetone and N,N-dimethylacetamide exhibit cholesteric behaviour, at room temperature. When approaching the lyotropic mesophase to solid transition, either by cooling or by solvent evaporation, very interesting arborescent structures of a seemingly fractal nature may be observed, depending on the kinetics of the transition. A banded texture can be observed when the polymer is sheared near the transition to the isotropic phase.

Mano, Francisca, Marta Martins, Isabel Sá-Nogueira, Susana Barreiros, João Paulo Borges, Rui Reis, Ana Rita Duarte, and Alexandre Paiva. "Production of Electrospun Fast-Dissolving Drug Delivery Systems with Therapeutic Eutectic Systems Encapsulated in Gelatin." AAPS PharmSciTech 18 (2017): 2579-2585. AbstractWebsite

Fast-dissolving delivery systems (FDDS) have received increasing attention in the last years. Oral drug delivery is still the preferred route for the administration of pharmaceutical ingredients. Nevertheless, some patients, e.g. children or elderly people, have difficulties in swallowing solid tablets. In this work, gelatin membranes were produced by electrospinning, containing an encapsulated therapeutic deep-eutectic solvent (THEDES) composed by choline chloride/mandelic acid, in a 1:2 molar ratio. A gelatin solution (30% w/v) with 2% (v/v) of THEDES was used to produce electrospun fibers and the experimental parameters were optimized. Due to the high surface area of polymer fibers, this type of construct has wide applicability. With no cytotoxicity effect, and showing a fast-dissolving release profile in PBS, the gelatin fibers with encapsulated THEDES seem to have promising applications in the development of new drug delivery systems.

Mano, Francisca, Ivo Aroso, Susana Barreiros, João Paulo Borges, Rui Reis, Ana Rita Duarte, and Alexandre Paiva. "Production of Poly(vinyl alcohol) (PVA) Fibers with Encapsulated Natural Deep Eutectic Solvent (NADES) Using Electrospinning." ACS Sustainable Chemistry & Engineering 3 (2015): 2504-2509. AbstractWebsite

Functionalized electrospun fibers are of great interest for biomedical applications such as in the design of drug delivery systems. Nevertheless, in some cases the molecules of interest have poor solubility in water or have high melting temperatures. These drawbacks can be overcome using deep eutectic solvents. In this work, poly(vinyl alcohol) (PVA), a common biodegradable biopolymer, was used to produce new functionalized fibers with the eutectic mixture choline chloride:citric acid in a molar ratio of (1:1) ChCl:CA (1:1), which was used as a model system. Fibers were produced from an aqueous solution with 7.8% (w/v) and 9.8% (w/v) of 95% hydrolyzed PVA and a 2% (v/v) of ChCl:CA (1:1). Smooth, uniform fibers with an average diameter of 0.4 μm were obtained with a content of 19.8 wt % of ChCl:CA (1:1) encapsulated.