Modulation of angiogenesis by topical application of leptin and high and low molecular heparin using the Japanese quail chorioallantoic membrane model

VEGF-modified PLA/HA nanocomposite fibrous membrane for cranial defect repair in rats

A major obstacle to bone tissue repair is the difficulty in establishing a rapid blood supply areas of bone defects. Vascular endothelial growth factor (VEGF)-infused tissue-engineered scaffolds offer a possible therapeutic option for these types of injuries. Their role is to accelerate angiogenesis and improve bone healing. In this study, we used electrostatic spinning and biofactor binding to construct polylactic acid (PLA)/hydroxyapatite (HA)-VEGF scaffold materials and clarify their pro-vascular role in bone defect areas for efficient bone defect repair. PLA/HA nanocomposite fibrous membranes were manufactured by selecting suitable electrostatic spinning parameters. Heparin and VEGF were bound sequentially, and then the VEGF binding and release curves of the fiber membranes were calculated. A rat cranial defect model was constructed, and PLA/HA fiber membranes bound with VEGF and unbound with VEGF were placed for treatment. Finally, we compared bone volume recovery and vascular recovery in different fibrous membrane sites. A VEGF concentration of 2.5 µg/mL achieved the maximum binding and uniform distribution of PLA/HA fibrous membranes. Extended-release experiments showed that VEGF release essentially peaked at 14 days. In vivo studies showed that PLA/HA fibrous membranes bound with VEGF significantly increased the number of vessels at the site of cranial defects, bone mineral density, bone mineral content, bone bulk density, trabecular separation, trabecular thickness, and the number of trabeculae at the site of defects in rats compared with PLA/HA fibrous membranes not bound with VEGF. VEGF-bound PLA/HA fibrous membranes demonstrate the slow release of VEGF. The VEGF binding process does not disrupt the morphology and structure of the fibrous membranes. The fibrous membranes could stimulate both osteogenesis and angiogenesis. Taken together, this research provides a new strategy for critical-sized bone defects repairing.

Anti-angiogenic effect of nano-formulated water soluble kaempferol and combretastatin in an in vivo chick chorioallantoic membrane model and HUVEC cells

The present study evaluated the efficacy of nano-formulated water-soluble kaempferol and combretastatin alone and combined against the native kaempferol and combretastatin on angiogenesis. The solvent evaporation method was used to synthesize the nano-formulated water-soluble kaempferol and combretastatin and characterized using various analyses such as dynamic light scattering (DLS) and Fourier-transform infrared (FT-IR) spectroscopy.The anti-angiogenic activity of native, nano-formulated water-soluble kaempferol and combretastatin was investigated by cell viability on HUVEC and A498 cell lines, while chick chorioallantoic membrane (CAM) assay was utilized to assess morphometric and histopathological changes, and mRNA expressions of VEGF-A and FGF2 using qRT-PCR. MTT assay results revealed that the combination of nano-formulated water-soluble kaempferol and combretastatin significantly reduced the cell viability compared to control, individual treatments of native, nano-formulated water-soluble kaempferol, and combretastatin. Morphometric analysis of CAM showed that treatment with nano-formulated water-soluble kaempferol and combretastatin caused a substantial decrease in density, vessel network, branch points, and nets of CAM blood vessels. The histopathological results of CAM showed the irregular shape of blood vessels at the thin stratum of chronic endoderm, and blood capillaries were diminished compared to the control. In addition, the mRNA expression levels of VEGF-A and FGF2 were significantly decreased compared with native forms. Therefore, the findings of this study indicate that nano-formulated water-soluble combretastatin and kaempferol suppress angiogenesis by preventing the activation of endothelial cells and suppressing factors of angiogenesis. Moreover, a combination of nano-formulated water-soluble kaempferol and combretastatin worked much better than individual treatments.

Chorioallantoic Membrane Models of Various Avian Species: Differences and Applications

The chorioallantoic membrane model (CAM) of an avian embryo is used as an experimental model in various fields of research, including angiogenesis research and drug testing, xenografting and cancer research, and other scientific and commercial disciplines in microbiology, biochemistry, cosmetics, etc. It is a low-cost, low-maintenance, and well-available in vivo animal model that is non-sentient and can be used as an alternative for other mammal experimental models. It respects the principles of the "3R" rule (Replacement, Reduction, and Refinement)-conditions set out for scientific community providing an essential framework for conducting a more human animal research, which is also in line with constantly raising public awareness of welfare and the ethics related to the use of animal experimental models. In this review, we describe the chorioallantoic membrane of an avian embryo, focusing on its properties and development, its advantages and disadvantages as an experimental model, and the possibilities of its application in various fields of biological research. Since the most common chicken CAM model is already well known and described in many publications, we are particularly focusing on the advantages and application of less known avian species that are used for the CAM model-quail, turkey, and duck.