Journal of tissue engineering and regenerative medicine
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J Tissue Eng Regen Med · Feb 2015
ReviewReview of vascularised bone tissue-engineering strategies with a focus on co-culture systems.
Poor angiogenesis within tissue-engineered grafts has been identified as a main challenge limiting the clinical introduction of bone tissue-engineering (BTE) approaches for the repair of large bone defects. Thick BTE grafts often exhibit poor cellular viability particularly at the core, leading to graft failure and lack of integration with host tissues. Various BTE approaches have been explored for improving vascularisation in tissue-engineered constructs and are briefly discussed in this review. ⋯ It will also address key questions regarding the generation of clinically relevant vascularized bone constructs as well as potential directions and considerations for research with the objective of pursuing engineered co-culture systems in other disciplines of vascularized regenerative medicine. The final objective is to generate serious and functional long-lasting vessels for sustainable angiogenesis that will enable enhanced cellular survival within thick voluminous bone grafts, thereby aiding in bone formation and remodelling in the long term. However, more evidence about the quality of blood vessels formed and its associated functional improvement in bone formation as well as a mechanistic understanding of their interactions are necessary for designing better therapeutic strategies for translation to clinical settings.
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J Tissue Eng Regen Med · Feb 2015
Treatment of penetrating brain injury in a rat model using collagen scaffolds incorporating soluble Nogo receptor.
Injuries and diseases of the central nervous system (CNS) have the potential to cause permanent loss of brain parenchyma, with severe neurological consequences. Cavitary defects in the brain may afford the possibility of treatment with biomaterials that fill the lesion site while delivering therapeutic agents. This study examined the treatment of penetrating brain injury (PBI) in a rat model with collagen biomaterials and a soluble Nogo receptor (sNgR) molecule. sNgR was aimed at neutralizing myelin proteins that hinder axon regeneration by inducing growth cone collapse. ⋯ Immunohistochemical staining demonstrated the composition of the cellular infiltrate to include macrophages, astrocytes and vascular endothelial cells. Isolated regions of the scaffold borders showed integration with surrounding viable brain tissue that included neurons and oligodendrocytes. While axon regeneration was not detected in the scaffolds, the cellular infiltration and vascularization of the lesion site demonstrated a modification of the injury environment with implications for regenerative strategies.