Alginate/poly (lactic-co-glycolic acid)/calcium phosphate cement scaffold with oriented pore structure for bone...

Bone tissue engineering requires scaffolds that support cell growth and mechanical stability. Current scaffolds often lack sufficient porosity or structural control. While open-pore structures are known to enhance cell infiltration, maintaining mechanical integrity remains a challenge. Prior research has shown that calcium phosphate cement (CPC) provides good biocompatibility but lacks structural reinforcement. Unidirectional freeze casting has been used to create directional pores, but its combination with polymer reinforcement is less explored. This gap motivated the investigation of alginate/CPC scaffolds with oriented pores. The need for scaffolds that balance porosity with mechanical strength is well established. No prior work had resolved how to integrate PLGA into CPC scaffolds to improve toughness. This study aimed to address these limitations through a novel composite design.

The study aimed to develop a composite scaffold using alginate, calcium phosphate cement (CPC), and poly (lactic-co-glycolic acid) (PLGA) to enhance mechanical properties while maintaining directional porosity. The specific problem was the lack of scaffolds that combine high porosity with sufficient compressive strength. The motivation stemmed from the need for bone tissue engineering materials that support cell infiltration and mechanical stability. The researchers proposed using unidirectional freeze casting to create oriented pores. They also sought to evaluate how PLGA infiltration affects scaffold performance. The goal was to control porosity through liquid-to-powder ratios. The study addressed the challenge of balancing structural integrity with pore architecture. This approach could advance scaffold design for bone regeneration applications.

The researchers used unidirectional freeze casting to fabricate alginate/CPC scaffolds with oriented pores. They varied the liquid-to-powder ratio to control porosity and pore size. Macropores were infiltrated with poly (lactic-co-glycolic acid) (PLGA) to reinforce the structure. Scaffold properties were analyzed using porosity measurements and mechanical testing. The radial and axial dimensions of macropores were assessed to evaluate pore orientation. Compressive strength and toughness were measured to determine mechanical performance. The role of PLGA was examined through three reinforcement mechanisms. The study combined material synthesis with structural and mechanical characterization.

At a liquid-to-powder ratio of 3.25, scaffolds achieved 89.24% total porosity with open directional macropores. Radial pore sizes ranged from 100 to 200 micrometers, while axial pores exceeded 1000 micrometers. Increasing the liquid-to-powder ratio reduced scaffold mechanical strength. PLGA infiltration significantly improved compressive strength and toughness. Three mechanisms of PLGA reinforcement were identified: load distribution, matrix strengthening, and defect patching. The composite scaffold preserved directional porosity while enhancing mechanical properties. The tubule-like pore structure supported potential cell infiltration and nutrient transport. These findings suggest that the composite scaffold could be suitable for bone tissue engineering applications.

The study demonstrated that alginate/PLGA/CPC scaffolds with oriented pores can be fabricated using unidirectional freeze casting. The scaffolds achieved high porosity and directional pore structures. PLGA reinforcement improved mechanical properties without compromising pore architecture. The three mechanisms of PLGA reinforcement were clearly identified. The researchers propose that these scaffolds could serve as a potential platform for bone tissue engineering. The findings suggest that the composite design balances structural integrity with functional porosity. The study supports the use of this approach to develop advanced scaffolds for regenerative medicine. These results may guide future scaffold development in tissue engineering applications.