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Solving the issue of infection associated with implanted bone substitutes is one of the modern challenges of the biomedical engineering field. The purpose of this study was to develop a novel porous scaffold with sufficient antibacterial activity for bone repair or regeneration. Porous nanohydroxyapatite/polyurethane (n-HA/PU) composite scaffolds containing different amounts of silver phosphate particles were prepared through thein situfoaming method. Subsequently, their physicochemical properties, antibacterial abilities, and preliminary cytocompatibilities were evaluated. The results indicated that the porosity and mechanical properties of the n-HA/PU scaffolds incorporated with Ag3PO4did not change significantly compared to n-HA/PU scaffold without Ag3PO4. The release of Ag+was time and concentration dependent, increasing with the immersion time and Ag3PO4percentage in the scaffolds. A continuous Ag+release can last more than 3 weeks. The antibacterial tests and cytocompatibility evaluation revealed that n-HA/PU scaffolds with 3 wt% Ag3PO4(n-HA/PU3) exhibit stronger antimicrobial effects as well as satisfactory cytocompatibility. The n-HA/PU3 scaffolds may hold great potential for application in the field of bone regeneration, especially for infection-associated bone defect repair. [ABSTRACT FROM PUBLISHER]

Tissue formation on scaffold outer edges after implantation may restrict cell infiltration and mass transfer to/from the scaffold center due to insufficient interconnectivity, leading to incidence of a necrotic core. Herein, a nano-hydroxyapatite/polyamide66 (n-HA/PA66) anisotropic scaffold with axially aligned channels was prepared with the aim to enhance pore interconnectivity. Bone tissue regeneration and infiltration inside of scaffold were assessed by rabbit cranial defect repair experiments. The amount of newly formed bone inside of anisotropic scaffold was much higher than isotropic scaffold, e.g., after 12 weeks, the new bone volume in the inner pores was greater in the anisotropic scaffolds (>50%) than the isotropic scaffolds (<30%). The results suggested that anisotropic scaffolds could accelerate the inducement of bone ingrowth into the inner pores in the non-load-bearing bone defects compared to isotropic scaffolds. Thus, anisotropic scaffolds hold promise for the application in bone tissue engineering. [ABSTRACT FROM AUTHOR]