Calcium Carbonate Coating of 3D-Printed PLA Scaffolds Intended for Biomedical Applications

Current strategies in biomedical engineering focus on enhancing the biofunctionality of polymer scaffolds for bone regeneration. Traditional methods involve incorporating ceramic additives to improve scaffold performance. While these approaches have shown promise, they often lack precision in distributing the additives at the cell-surface interface. Prior research has shown that ceramic particles can improve cell adhesion and proliferation, but the exact methods for controlled deposition remain limited. This gap motivated the exploration of new coating techniques that could concentrate functionality at the surface. No prior work had resolved how to evenly coat polymer scaffolds with ceramics using heat and pressure. The need for a method that enhances mechanical and surface properties without compromising degradation behavior is evident. This study addresses these challenges by introducing a novel coating strategy. The potential for such methods to influence tissue engineering applications is significant.

The aim of this study is to develop and evaluate a novel coating method for 3D-printed polylactic acid (PLA) scaffolds intended for biomedical applications. The specific problem addressed is the need for a controlled and effective way to incorporate ceramic additives at the scaffold surface to improve biofunctionality. The motivation stems from the limitations of existing methods in achieving uniform ceramic distribution and strong bonding. The study focuses on calcium carbonate (CaCO₃) as the additive material due to its favorable properties for bone regeneration. The goal is to assess whether this coating method can enhance mechanical properties and surface characteristics. The study also seeks to evaluate how the coating affects scaffold degradation behavior. By addressing these questions, the research contributes to the development of more effective scaffolds for tissue engineering. The findings may inform future strategies for scaffold design and functionalization.

The study employed a pressure-assisted and heat-induced method to coat 3D-printed PLA scaffolds with calcium carbonate particles. The coating process was designed to ensure even distribution of the ceramic layer across the scaffold surface. Optical microscopy was used to assess the uniformity of the CaCO₃ coating. Scanning electron microscopy provided detailed surface imaging to evaluate particle coverage and bonding. Water contact angle measurements were conducted to determine surface hydrophilicity. Compression testing was performed to assess mechanical properties such as modulus. An enzymatic degradation study was carried out to compare the pH stability of coated and uncoated scaffolds. The results were analyzed to determine the effectiveness of the coating method in enhancing scaffold functionality. The methodology combined structural and functional evaluations to validate the coating's performance.

The CaCO₃ particles were evenly distributed across the scaffold surface, covering more than 60% of the area. The coating represented approximately 7% of the total scaffold weight. A strong bonding interface was achieved between the ceramic layer and the PLA substrate. The thin CaCO₃ layer (~20 µm) significantly increased the compression modulus of the scaffolds by up to 14%. Surface roughness was enhanced, which may improve cell adhesion. The coating also increased hydrophilicity, as indicated by lower water contact angles. The degradation study showed that coated scaffolds maintained a stable pH of ~7.6 ± 0.1 during testing. In contrast, uncoated scaffolds caused a significant drop in pH to 5.07 ± 0.1. These results suggest that the coating method effectively improves both mechanical and surface properties. The pH stability of the coated scaffolds indicates their potential for biomedical applications.

The study demonstrated that a pressure-assisted and heat-induced coating method can effectively apply calcium carbonate to 3D-printed PLA scaffolds. The coating improved mechanical properties, surface roughness, and hydrophilicity, as reported by the authors. The strong bonding interface between the ceramic layer and the polymer substrate was confirmed through imaging and mechanical testing. The coated scaffolds maintained a stable pH during degradation, unlike uncoated scaffolds. These findings suggest that the method enhances scaffold functionality for biomedical applications. The authors propose that this approach could be useful in tissue engineering contexts requiring controlled surface modification. The results support further evaluation of the coated scaffolds in biological environments. The study highlights the potential of ceramic coatings to improve scaffold performance in bone regeneration.