BACKGROUND: Introduction of pro-angiogenic cells into tissue-engineered (TE) constructs (prevascularisation) is apromising approach to overcome delayed neovascularisation of such constructs post-implantation. Accordingly, in thisstudy, we examined the contribution of human dermal microvascular endothelial cells (HDMECs) and human dermalfibroblasts (HDFs) alone and in combination on the formation of new blood vessels in ex-ovo chick chorioallantoicmembrane (CAM) assay. METHODS: Poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV) and polycaprolactone (PCL) were first examined interms of their physical, mechanical, and biological performances. The effect of gelatin coating and co-culture conditions onenhancing endothelial cell viability and growth was then investigated. Finally, the angiogenic potential of HDMECs andHDFs were assessed macroscopically and histologically after seeding on simple electrospun PHBV scaffolds either inisolation or in indirect co-culture using an ex-ovo CAM assay. RESULTS: The results demonstrated that PHBV was slightly more favourable than PCL for HDMECs in terms of cellmetabolic activity. The gelatin coating of PHBV scaffolds and co-culture of HDMECs with HDFs both showed a positiveimpact on HDMECs viability and growth. Both cell types induced angiogenesis over 7 days in the CAM assay either inisolation or in co-culture. The introduction of HDMECs to the scaffolds resulted in the production of more blood vessels inthe area of implantation than the introduction of HDFs, but the co-culture of HDMECs and HDFs gave the most significantangiogenic activity. CONCLUSION Our findings showed that the in vitro prevascularisation of TE constructs with HDMECs and HDFs aloneor in co-culture promotes angiogenesis in implantable TE constructs.

BACKGROUND: Introduction of pro-angiogenic cells into tissue-engineered (TE) constructs (prevascularisation) is apromising approach to overcome delayed neovascularisation of such constructs post-implantation. Accordingly, in thisstudy, we examined the contribution of human dermal microvascular endothelial cells (HDMECs) and human dermalfibroblasts (HDFs) alone and in combination on the formation of new blood vessels in ex-ovo chick chorioallantoicmembrane (CAM) assay. METHODS: Poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV) and polycaprolactone (PCL) were first examined interms of their physical, mechanical, and biological performances. The effect of gelatin coating and co-culture conditions onenhancing endothelial cell viability and growth was then investigated. Finally, the angiogenic potential of HDMECs andHDFs were assessed macroscopically and histologically after seeding on simple electrospun PHBV scaffolds either inisolation or in indirect co-culture using an ex-ovo CAM assay. RESULTS: The results demonstrated that PHBV was slightly more favourable than PCL for HDMECs in terms of cellmetabolic activity. The gelatin coating of PHBV scaffolds and co-culture of HDMECs with HDFs both showed a positiveimpact on HDMECs viability and growth. Both cell types induced angiogenesis over 7 days in the CAM assay either inisolation or in co-culture. The introduction of HDMECs to the scaffolds resulted in the production of more blood vessels inthe area of implantation than the introduction of HDFs, but the co-culture of HDMECs and HDFs gave the most significantangiogenic activity. CONCLUSION Our findings showed that the in vitro prevascularisation of TE constructs with HDMECs and HDFs aloneor in co-culture promotes angiogenesis in implantable TE constructs.