Angiogenic stimulation strategies in bone tissue regeneration

Current tissue engineering strategies in bone repair and regeneration have limitations regarding tissue rejection, insufficient blood supply, and tissue integration. Specific host response results in isolation, degeneration, and subsequent loss of function of the implanted/scaffold biomaterial. Therefore, strategies to increase the interplay between angiogenesis and complex bone tissue formation are required to develop fully functional vascularized bone tissue. Angiogenesis is essential for oxygen/nutrient supply, waste removal, endothelial/stem cell homing, and the release of mitogenic/angiogenic/osteogenic factors. Hence, the challenge lies in understanding the complex interdependence of angiogenesis with neo-bone formation. Therefore, recent bone tissue regeneration strategies have focused on biomaterial development concerning induction of neovascularization and subsequent angiogenesis. Scaffold architecture (macro/micro/nano) scales, culture conditions (3-Dimension, hypoxia, etc), stimuli-dependent delivery of angiofactors, and gene delivery may significantly modulate vascularization in tissue-engineered products. Therefore, the current review discusses the key mechanisms/steps involved in defining the relationship between angiogenic and osteogenic factors. The recent strategies incorporating the above understanding in the development of bone tissue-engineered constructs are also deliberated. Eventually, these strategies may give the potential way forward to develop a bioengineered, vascularized bone tissue construct for implant applications.

Automated summary

Current tissue engineering strategies in bone repair and regeneration have limitations, thus there is a need to develop fully functional vascularized bone tissue. Angiogenesis plays a crucial role in providing oxygen, nutrients, cell migration, and biological factors for bone tissue. To address the complex relationship between angiogenesis and bone formation, current research focuses on biomaterial development to induce neovascularization and angiogenesis.