Fibrosis and hepatic regeneration mechanism Esmeralda Zuñiga Aguilar, Odin Ramírez-Fernández

Currently, there are several techniques for modified cell culture surfaces under research to improve cell growth and adhesion. Recently, different methods have been used for surface coating, using biomolecules that enhance cell attachment and growth of nerve cells from spinal cord, such as the use of Poly-DL-Ornithine/Laminin. Plasma-polymerized pyrrole (PPy)-treated surfaces have showed improvement on surfaces biocompatibility with the cells in culture since they do not interfere with any of the biological cell functions. In the present work, we present a novel mouse nerve cell culture technique, using PPy-treated cell culture surfaces. A comparative study of cell survival using Poly-DL-Ornithine/Laminin-treated surfaces was performed. Our results of cell survival when compared with data already reported by other investigators, show that cells cultured on the PPy-modified surface increased survival up to 21 days when compared with Poly-DL-Ornithine/Laminin-coated culture, where 8 days cell survival was obtained. There were electrical and morphological differences in the nerve cells grown in the different surfaces. By comparing the peak ion currents of Poly-DL-Ornithine/Laminin-seeded cells for 8 days with cells grown for 21 days on PPy, an increase of 516% in the Na⁺ current and 127% in K⁺ currents in cells seeded on PPy were observed. Immunofluorescence techniques showed the presence of cell synapses and culture viability after 21 days. Our results then showed that PPy-modified surfaces are an alternative culture method that increases nerve cells survival from lumbar spinal cord cell culture by preserving its electrical and morphological features.

Background: The increasing demand for dental implants necessitates the exploration of advanced materials and manufacturing techniques. Three-dimensional (3D) printing has emerged as a viable method for producing custom dental implants, allowing for intricate designs and improved patient-specific fits. This study focuses on the design and structural deformation assessment of 3D-printed dental implants using Finite Element Analysis (FEA). By simulating the mechanical behavior of these implants under realistic loading conditions, we aim to evaluate their performance and predict potential failure points, ultimately enhancing their reliability and longevity in clinical applications. Objective: The primary objective of this study is to conduct a comprehensive design and structural deformation assessment of three-dimensional (3D) printed dental implants using Finite Element Analysis (FEA). Specifically, the study aims to: Evaluate stress distribution and deformation patterns in three 3D-printed dental implant designs under simulated physiological loading. Compare the stiffness, strength, and elastic behavior of PEEK and CFR-PEEK under occlusal forces. Identify failure points in implants and bone–implant interfaces by analyzing high stress concentrations. Predict the biomechanical behavior of a novel dental implant by determining its elastic modulus through finite element analysis (FEA). Methods: Three models 3D were designed to understand stress distribution with different structures using PEEK as biomaterial, with 4 test conditions modeled and compared. An occlusal load was applied (230 N at 90˚ and 30˚) on the implants. Isotropic, linear elastic, and homogeneous were considerate as properties of the components. Results: Under axial loads, all models stayed within physiological stress limits, while under 30° oblique loading, Model 3 showed the lowest stress, strain, and pressure. Conclusions: FEA results indicate that 3D-printed dental implants, particularly the optimized Model 3, maintain safe stress levels under axial and oblique loads, supporting their potential for immediate loading. However, due to numerical limitations, experimental validation remains necessary to advance implant designs that optimize bone regeneration and material efficiency.

In this work, we report the synthesis and evaluation of a bioink based on marine collagen, chitosan, and silica-doped hydroxyapatite (HA–SiO₂) for extrusion-based 3D bioprinting. FTIR spectroscopy confirmed amide (I–III) and phosphate/siloxane signals, TGA showed initial dehydration and degradation stages compatible with the process’s thermal handling, and SEM revealed an interconnected porous microstructure. Rheologically, the ink exhibited elastic dominance (G′ > G″) within the linear range and pseudoplastic, shear-thinning behavior—consistent with pneumatic extrusion. Process evaluation on a BIO X printer (14 G nozzle, low print speeds, moderate pressure, cartridge at 37 °C to 45 °C, and a cooled build platform) enabled deposition of strands with local shape retention. However, filament continuity was limited and line width varied, indicating only preliminary printability and a narrow operating window. Overall, physicochemical, microstructural, and rheological evidence supports the formulation’s viability as a starting point for scaffold fabrication.