3D plotting of growth factor loaded calcium phosphate cement scaffolds

Traditional implant fabrication methods offer limited control over geometry and biological integration. Additive manufacturing has introduced new possibilities for customizing implant architecture. However, integrating biological components into inorganic scaffolds remains challenging. Prior research has shown that hydrogels and biopolymers can incorporate growth factors but lack mechanical strength. This gap motivated the development of a method to embed growth factors into calcium phosphate cement scaffolds during fabrication. Existing approaches often involve aqueous processing, which can cause leaching of sensitive proteins. No prior work had resolved how to maintain protein stability during cement setting. The need for a mild fabrication process that preserves biological activity is critical for bone regeneration applications. This study addresses the challenge of integrating growth factors into calcium phosphate scaffolds without compromising structural integrity. The novelty lies in using a water-immiscible carrier to avoid protein loss during setting. The approach aims to enable spatially controlled delivery of bioactive components in bone tissue engineering.

The goal was to develop a method for integrating growth factors into calcium phosphate cement scaffolds during 3D plotting. The study aimed to evaluate whether encapsulated proteins could be preserved during cement setting. Researchers sought to compare mechanical and structural properties of scaffolds set in humidity versus water. The motivation was to avoid protein leaching while ensuring proper cement hardening. The approach involved encapsulating proteins in chitosan/dextran microparticles for stability. The study also aimed to assess cytocompatibility and bioactivity of the loaded scaffolds. A key objective was to demonstrate the feasibility of this method for bone regeneration applications. The method needed to allow precise spatial integration of biological components into the scaffold.

Researchers used 3D plotting of a CPC paste with a water-immiscible carrier liquid. BSA and VEGF were encapsulated in chitosan/dextran sulphate microparticles. These microparticles were freeze-dried and mixed into the CPC paste. Scaffolds were plotted and set in a water-saturated atmosphere. Mechanical and structural properties were analyzed using XRD and compression testing. Cytocompatibility was assessed by culturing mesenchymal stem cells on the scaffolds. Bioactivity of VEGF was tested in indirect and direct endothelial cell cultures. The study compared scaffolds set in humidity versus those set in water. Surface topography, porosity, and compressive modulus were evaluated. The method allowed for controlled integration of biological components during fabrication.

Scaffolds set in humidity retained encapsulated proteins without significant leaching. XRD analysis confirmed successful cement setting under humid conditions. Humidity-set scaffolds showed improved structural properties compared to water-set ones. No swelling or cracking was observed in humidity-set scaffolds. Surface topography and porosity differed between the two setting methods. Compressive modulus of humidity-set scaffolds was distinct from water-set scaffolds. Mesenchymal stem cells cultured on humidity-set scaffolds remained viable over 21 days. VEGF bioactivity was preserved, as shown in endothelial cell experiments. The method enabled spatially controlled integration of growth factors into CPC scaffolds. The approach demonstrated feasibility for bone regeneration applications.

The study demonstrated a method to integrate growth factors into CPC scaffolds during 3D plotting. Humidity setting preserved protein stability while allowing proper cement hardening. The approach enabled controlled spatial integration of biological components. Humidity-set scaffolds exhibited improved structural properties compared to water-set ones. Cytocompatibility was confirmed through stem cell and endothelial cell experiments. The method offers advantages over hydrogel-based approaches in terms of mechanical strength. The procedure allows for individualized implants with tailored biological features. The findings suggest potential applications in bone tissue engineering and regenerative medicine.