In order to provide a second economic life to agave fibers, an important waste material from the production of tequila, filaments based on polylactic acid (PLA) were filled with agave fibers (0, 3, 5, 10 wt%), and further utilized to produce biocomposites by fused deposition modeling (FDM)-based 3D printing at two raster angles (−45°/45° and 0°/90°). Differential scanning calorimetry, water uptake, density variation, morphology, and composting of the biocomposites were studied. The mechanical properties of the biocomposites (tensile, flexural, and Charpy impact properties) were determined following ASTM international norms. The addition of agave fibers to the filaments increased the crystallinity value from 23.7 to 44.1%. However, the fibers generated porous structures with a higher content of open cells and lower apparent densities than neat PLA pieces. The printing angle had a low significant effect on flexural and tensile properties, but directly affected the morphology of the printed biocomposites, positively influenced the impact strength, and slightly improved the absorption values for biocomposites printed at −45°/45°. Overall, increasing the concentrations of agave fibers had a detrimental effect on the mechanical properties of the biocomposites. The disintegration of the biocomposites under simulated composting conditions was slowed 1.6-fold with the addition of agave fibers, compared to neat PLA.

Metal nanoparticles (NPs), particularly gold nanorods (AuNRs), appear as excellent platforms not only to transport and deliver bioactive cargoes but also to provide additional therapeutic responses for diseased cells and tissues and/or to complement the action of the carried molecules. In this manner, here, we optimized a previous developed metal-based nanoplatform composed of an AuNR core surrounded by a polymeric shell constructed by means of the layer-by-layer approach, and in which very large amounts of the antineoplasic drug doxorubicin (DOXO) in a single loading step and targeting capability thanks to an outer hyaluronic acid layer were incorporated by means of an optimized fabrication process (PSS/DOXO/PLL/HA-coated AuNRs). The platform retained its nanometer size with a negative surface charge and was colloidally stable in a range of physiological conditions, in which only in some of them some particle clustering was noted with no precipitation. In addition, the dual stimuli-responsiveness of the designed nanoplatform to both endogenous proteases and external applied light stimuli allows to perfectly manipulate the chemodrug release rates and profiles to achieve suitable pharmacodynamics. It was observed that the inherent active targeting abilities of the nanoplatfom allow the achievement of specific cell toxicity in tumoral cervical HeLa cells, whilst healthy ones such as 3T3-Balb fibroblast remain safe and alive in agreement with the detected levels of internalization in each cell line. In addition, the bimodal action of simultaneous chemo- and photothermal bioactivity provided by the platform largely enhances the therapeutic outcomes. Finally, it was observed that our PSS/DOXO/PLL/HA-coated AuNRs induced cell mortality mainly through apoptosis in HeLa cells even in the presence of NIR light irradiation, which agrees with the idea of the chemo-activity of DOXO predominating over the photothermal effect to induce cell death, favoring an apoptotic pathway over necrosis for cell death.

In most of the cases, the diagnostic and therapy stages are carried out independently and this lead to delays in the application of the treatments and, therefore, an important risk to the patients´ health. To overcome these incoveniences, in the few last years theranostic has reached an important role to join in a unique nanoplatform therapeutic treatment, action and monitoring of the response to simultaneous therapy. Thus, we designed an hybrid nanosystems based on gold nanoparticles capable of simultaneously combining their potential as a photodynamic therapeutic agent (PDT), plasmonic photothermal therapy (PPTT) and/or chemotherapy to kill malignant cells. In order to do that, gold nanorods (GNR) were functionalized by the layer-by-layer (LbL) assembly technique using alternate layers of polyelectrolytes (PE): poly (styrene sulfonate) (PSS) and poly-L-lysine (PLL) as anionically and cationically charged polymeric layers, and an outer layer of hyaluronic acid (HA) to provide the hybrid particles with sufficient colloidal stability and steering ability. Doxorrubicin (DOXO) and SiRNA were added by electrostatic interactions to the PSS and PLL layers for providing chemo- and genetic therapy, respectively, controlling the % weight and encapsulated efficiency of doxorubicin and SiRNA with their calibration curve. To provide the PDT capabilities to the nanoplatform, the green indocyanine photosensitizer (ICG) was previously conjugated to the PLL polymer and assembled into the nanoplatform by electrostatic interactions, checking its efficiency with the fluorometer. In this way, hybrid particles formed by GNR coated with PSS/DOXO/PLL @ [email protected] / HA layers were obtained, in which the therapeutic PDT activity of the dye ICG, chemo- activity of DOXO and the photothermal properties of the plasmonic metal nanoparticles can be simultaneously be applied for efficient cancer therapeutics. Nanoplatforms were characterizated by UV-Vis, FTIR and RAMAN spectroscopy, -potential and TEM. In addition, PPTT therapy of the nanoplatforms was evaluated at different irradiation powers. Finally, single oxygen ( 1 O 2 ) production under NIR light excitation by the hybrid nanosystem was evaluated in vitro at several power intensities by means of fluorescence and absorbance spectroscopies and fluorescent microscopy.

Alterations in neurogenesis result in the inevitable loss of brain nervous tissue and cause neurodegenerative diseases, such as Parkinson’s disease (PD), Alzheimer’s disease (AD), and Huntington’s disease (HD). In this regard, hydrogels based on natural biopolymers have attractive properties, such as excellent biocompatibility, a low immune response, and a significant similarity to the extracellular matrix (ECM) of tissues, thus supporting cell proliferation and migration. Human ECM is composed by relatively small amounts of fibrous, proteins, and polysaccharides. For example, scaffolds composed of gelatin and hyaluronic acid are highly abundant components in human ECM. The methacrylation of hyaluronic acid (HAMA) and gelatin (GelMA) through carboxyl and hydroxyl groups under UV light radiation at 365 nm produce polymeric scaffolds with elastic moduli similar to tissues, and, therefore, potential candidates to adhere, host, and facilitate cell proliferation and differentiation, which are dependent on their mechanical properties. In this work, the mechanical, thermal, and morphological properties of HAMA and GelMA hydrogel mixtures were studied and characterized via linear rheological measurements, thermogravimetric analysis (TGA), and scanning electron microscopy (SEM).