3-Dimensional functionalized polycaprolactone-hyaluronic acid hydrogel constructs for bone tissue engineering.

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Alveolar bone regeneration is critical for periodontology and dental implantology.
• Developing effective strategies for bone regeneration remains a significant clinical challenge.
• 3-D printed scaffolds offer promising platforms for bone tissue engineering.

Purpose of the Study:

• To assess the mineralized tissue forming potential of 3-D printed medical grade polycaprolactone (mPCL) constructs.
• To evaluate mPCL constructs containing osteoblasts (OB) within a hyaluronic acid (HA)-hydrogel incorporating bone morphogenetic protein-7 (BMP-7).
• To investigate the efficacy of these constructs in vitro and in vivo for alveolar bone regeneration.

Main Methods:

• Human osteoblasts (OB) ± BMP-7 were encapsulated in HA-hydrogels.
• In vitro assessments included cell viability, osteogenic gene expression, mineralized tissue formation, and BMP-7 release.
• In vivo evaluation utilized an athymic rat model for ectopic bone formation in mPCL-hydrogel constructs.

Main Results:

• Osteoblast encapsulation in HA-hydrogels maintained cell viability.
• 3-D cultures demonstrated mineralized collagenous matrix formation after 6 weeks.
• BMP-7 release was sustained, enhancing osteogenic gene expression in vitro.
• mPCL-hydrogel constructs with BMP-7 significantly increased vascularized bone-like tissue volume in vivo after 4 weeks.

Conclusions:

• Functionalized mPCL-HA hydrogel constructs create a favorable environment for bone tissue engineering.
• Encapsulated cells contributed to mineralized tissue formation both in vitro and in vivo.
• BMP-7 alone demonstrated a more significant impact on bone regeneration compared to constructs with encapsulated cells.