Combining tunable proteolytic sequences and a VEGF-mimetic peptide for the spatiotemporal control of angiogenesis within Elastin-Like Recombinamer scaffolds

Abstract

One of the main challenges in regenerative medicine is the spatiotemporal control of angiogenesis, which is key for the successful repair of many tissues, and determines the proper integration of the implant through the generation of a functional vascular network. To this end, we have designed a three-dimensional (3D) model consisting of a coaxial binary elastin-like recombinamer (ELR) tubular construct. It displays fast and slow proteolytic hydrogels on its inner and outer part, respectively, both sensitive to the urokinase plasminogen activator protease.The ELRs used to build the scaffold included crosslinkable domains to stabilize the structure and a conjugated VEGF-derived peptide (QK) to induce angiogenesis. The mechanical and morphological evaluation of the ELR hydrogels proved their suitability for soft tissue regeneration. In addition, in vitro studies evidenced the effect of the QK peptide on endothelial cell spreading and anastomosis. Moreover, immunohistochemical analyses after subcutaneous implantation of the ELR hydrogels in mice showed the induction of a low macrophage response that resolved over time. The implantation of the 3D model constructs evidenced the ability of the fast proteolytic sequence and the QK peptide to guide cell infiltration and capillary formation in the pre-designed arrangement of the constructs. These results set the basis for the application of this type of scaffolds in regenerative medicine, where spatiotemporally controlled vascularization will help in the promotion of an optimal tissue repair.

Mesenchymal Stromal Cells Combined With Elastin-Like Recombinamers Increase Angiogenesis In Vivo After Hindlimb Ischemia

“…Upon macroscopic and histological evaluation, we did not observe major changes despite minor inflammation sites in muscles where the biomaterial was injected alone or with MSCs and a small collagen reaction in muscles injected with MSCs. In accordance with these findings, some groups have also described the absence of important inflammation response when ELR-based hydrogels are injected subcutaneously in mice (Ibáñez-Fonseca et al, 2018;Ibáñez-Fonseca et al, 2020;González-Pérez et al, 2021). It has also been reported that there is no effect on collagen fiber distribution neither in a situation of ischemia nor after treatment with biomaterials or MSC (Amani et al, 2021) as is observed in our samples.…”

Natural polymer-based scaffolds for soft tissue repair

“…The cells can bind to the scaffolds and then proliferate and differentiate ( Avolio et al, 2017 ; Turnbull et al, 2020 ; Abdollahiyan et al, 2021 ; Bianchi et al, 2021 ; Masson-Meyers and Tayebi, 2021 ). In addition, growth factors can be incorporated into the scaffolds to advance tissue regrowth and repair ( Hormozi et al, 2017 ; Kakudo et al, 2020 ; González-Pérez et al, 2021 ). To meet the clinical needs, the scaffolds for soft tissue repair should have tissue-matching mechanical properties, excellent biocompatibility, and appropriate biodegradability.…”

Biohybrid elastin-like venous valve with potential for in situ tissue engineering

“…opening and closing cycles) ( Urry et al, 1976 ). These protein-engineered polymers can prevent the formation of fibrotic tissue and promote the pro-healing type-2 macrophages over the pro-inflammatory type-1 macrophages ( Ibáñez-Fonseca et al, 2020 ; González-Pérez F. et al, 2021 ). Moreover, their recombinant nature makes them a multivalent platform for the development of cell-instructive hydrogels for in situ TE with precise control of their properties and composition ( Girotti et al, 2015 ).…”

“…For example, multiple bioactive motifs (e.g., cell-adhesive motifs or protease-sensitive sequences among others) can be incorporated into their backbone, thus conferring enhanced cell migration and matrix remodeling capacities. Recent studies have explored the development of ELR hydrogels with protease cleavage sites and bioabsorbable properties, which demonstrated to favor stromal cell-colonization, degradation and remodeling upon the in vivo implantation ( Flora et al, 2019 ; González-Pérez F. et al, 2021 ; Contessotto et al, 2021 ). This cell-mediated degradation capacity is highly interesting for an in situ approach, in which a balance between the scaffold degradation and the cell colonization and remodeling is required.…”