Regression and persistence: remodelling in a tissue engineered axial vascular assembly

Abstract

In later stages of vasculoangiogenesis a vascular network is going through a metamorphosis for optimal perfusion and economy of energy. In this study we make a quantitative approach to phenomena of remodelling in a bioartificial neovascular network and suggest variance of calibre as a parameter of neovascular maturation. For this study, 18 male Lewis rats were subjected to the AV loop operation in combination with a hard porous biogenic matrix and an isolation chamber. The animals were allocated into three groups for different explantation intervals set to 2, 4 and 8 weeks, respectively. Collective attributes like vascular density, percent fractional area and variance of calibre were evaluated for a predefined region of interest (ROI). Late morphogenesis was evaluated by means of scanning electron microscopy. After the fourth week the absolute number of vessels within the ROI decreased (P < 0.03) whereas, on the contrary, the fractional area of all segments increased (P < 0.02). The variance in calibre was significantly increased in the 8-week group (P < 0.05). Lymphatic growth after week 4, early pericyte migration as well as intussusceptive angiogenesis were identified immunohistologically. Phenomena of remodelling were evaluated quantitatively in a neovascular network and variance could be proposed as a parameter of net vascular maturation.

Wide Topical Negative Pressure Wound Dressing Treatment for Patients Undergoing Abdominal Dermolipectomy Following Massive Weight Loss

“…One reason may be the disorganization of the extracellular matrix, the lack of organized collagen fibres and the excessive scarring present also on a macroscopic level [24,25]. Despite the numerous advancements in the field of tissue engineering, there is as yet no alternative treatment available other than to reduce the superfluous skin of bariatric patients [26][27][28]. In order to reduce complication rates and optimize wound healing after these operations, several surgical techniques were established in the recent years.…”

Axially vascularised mandibular constructs: Is it time for a clinical trial?

“…The long-term studies at the preclinical level, however, have shown that the vascular bed matures with time, leading to dumping down of the direct arteriovenous jet (Polykandriotis et al, 2009;Polykandriotis et al, 2007).…”

“…12 arteriovenous (AV) flow so that the construct ends up with an afferent artery, an efferent vein and a well-vascularized parenchyma in between (Polykandriotis et al, 2007;Arkudas et al, 2013;Polykandriotis et al, 2009).…”

Tissue Engineering of Skeletal Muscle

“…5) which can be implanted into various matrices (Polykandriotis et al 2008). Thus, vascularization in general as well as number and pattern of vessel ingrowth of different matrices can be analyzed (Arkudas et al 2010, Polykandriotis et al 2009) and the vascularized matrix offers a platform for tissue engineering for skeletal (Messina et al 2005) or cardiac (Morritt et al 2007) muscle in vivo. The feasibility of the AV-loop model in large animals ) has been demonstrated recently and poses another step towards a more clinical setting (Beier et al 2010).…”