In recent years, the chorioallantoic membrane (CAM) has emerged as a crucial component of biocompatibility testing for biomaterials designed for regenerative strategies and tissue engineering applications. This study explores angiogenic potential of an innovative acellular and porous biopolymer scaffold, based on polyhydroxybutyrate and chitosan (PHB/CHIT), using the ex ovo quail CAM assay as an alternative to the conventional chick CAM test. On embryonic day 6 (ED6), we placed the tested biomaterials on the CAM alone or soaked them with various substances, including vascular endothelial growth factor (VEGF-A), saline, or the endogenous angiogenesis inhibitor Angiostatin. After 72 h (ED9), we analyzed blood vessels formation, a sign of ongoing angiogenesis, in the vicinity of the scaffold and within its pores. We employed marker for cell proliferation (PHH3), embryonic endothelium (WGA, SNA), myofibroblasts (α-SMA), and endothelial cells (QH1) for morphological and histochemical analysis. Our findings demonstrated the robust angiogenic potential of the untreated scaffold without additional influence from the angiogenic factor VEGF-A. Furthermore, gene expression analysis revealed an upregulation of pro-angiogenic growth factors, including VEGF-A, ANG-2, and VE-Cadherin after 5 days of implantation, indicative of a pro-angiogenic microenvironment. These results underscore the inherent angiogenic potential of the PHB/CHIT composite. Additionally, monitoring of CAM microvilli growing to the scaffold provides a methodology for investigating the biocompatibility of materials using the ex ovo quail CAM assay as a suitable alternative model compared to the chicken CAM platform. This approach offers a rapid screening method for biomaterials in the field of tissue repair/regeneration and engineering.

• Klíčová slova
• Angiogenesis, Avian animal model, Bone regeneration, Chitosan, Polyhydroxybutyrate,
• MeSH
• biokompatibilní materiály * farmakologie   MeSH
• chitosan * farmakologie   MeSH
• chorioalantoická membrána * účinky léků   MeSH
• fyziologická neovaskularizace účinky léků   MeSH
• křepelky a křepelovití embryologie   MeSH
• testování materiálů MeSH
• tkáňové podpůrné struktury chemie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• biokompatibilní materiály * MeSH
• chitosan * MeSH

BACKGROUND: Endothelial dysfunction is an early manifestation of cardiovascular disease (CVD) and consistently observed in patients with chronic kidney disease (CKD). We hypothesized that CKD is associated with systemic damage to the microcirculation, preceding macrovascular pathology. To assess the degree of "uremic microangiopathy", we have measured microvascular density in biopsies of the omentum of children with CKD. PATIENTS AND METHODS: Omental tissue was collected from 32 healthy children (0-18 years) undergoing elective abdominal surgery and from 23 age-matched cases with stage 5 CKD at the time of catheter insertion for initiation of peritoneal dialysis. Biopsies were analyzed by independent observers using either a manual or an automated imaging system for the assessment of microvascular density. Quantitative immunohistochemistry was performed for markers of autophagy and apoptosis, and for the abundance of the angiogenesis-regulating proteins VEGF-A, VEGF-R2, Angpt1 and Angpt2. RESULTS: Microvascular density was significantly reduced in uremic children compared to healthy controls, both by manual imaging with a digital microscope (median surface area 0.61% vs. 0.95%, p<0.0021 and by automated quantification (total microvascular surface area 0.89% vs. 1.17% p = 0.01). Density measured by manual imaging was significantly associated with age, height, weight and body surface area in CKD patients and healthy controls. In multivariate analysis, age and serum creatinine level were the only independent, significant predictors of microvascular density (r2 = 0.73). There was no immunohistochemical evidence for apoptosis or autophagy. Quantitative staining showed similar expression levels of the angiogenesis regulators VEGF-A, VEGF-receptor 2 and Angpt1 (p = 0.11), but Angpt2 was significantly lower in CKD children (p = 0.01). CONCLUSIONS: Microvascular density is profoundly reduced in omental biopsies of children with stage 5 CKD and associated with diminished Angpt2 signaling. Microvascular rarefaction could be an early systemic manifestation of CKD-induced cardiovascular disease.

• MeSH
• angiopoetin-1 krev   MeSH
• angiopoetin-2 krev   MeSH
• apoptóza genetika   MeSH
• autofagie genetika   MeSH
• biologické markery krev   MeSH
• biopsie MeSH
• chronická renální insuficience krev   genetika   patologie   MeSH
• dítě MeSH
• kardiovaskulární nemoci krev   genetika   patologie   MeSH
• kojenec MeSH
• lidé MeSH
• mikrocévy patologie   MeSH
• mikrocirkulace genetika   MeSH
• mladiství MeSH
• novorozenec MeSH
• peritoneální dialýza MeSH
• předškolní dítě MeSH
• receptor 2 pro vaskulární endoteliální růstový faktor krev   MeSH
• regulace genové exprese MeSH
• vaskulární endoteliální růstový faktor A krev   MeSH
• Check Tag
• dítě MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• angiopoetin-1 MeSH
• angiopoetin-2 MeSH
• ANGPT1 protein, human MeSH Prohlížeč
• ANGPT2 protein, human MeSH Prohlížeč
• biologické markery MeSH
• KDR protein, human MeSH Prohlížeč
• receptor 2 pro vaskulární endoteliální růstový faktor MeSH
• vaskulární endoteliální růstový faktor A MeSH
• VEGFA protein, human MeSH Prohlížeč