Porous biomaterials are of significant interest in a variety of biomedical applications as they enable the diffusion of nutrients and gases as well as the removal of metabolic waste from implants. Pores also provide 3D spaces for cell compartmentalization and the development of complex structures such as vasculature and the extracellular matrix. Given the variation in the extracellular matrix composition across and within different tissues, it is necessary to tailor the physicochemical characteristics of biomaterials and or surfaces thereof for optimal bespoke applications. In this regard, different synthetic and natural polymers have seen increased usage in the development of biomaterials and surface coatings; among them, elastin-like polypeptides and their recombinant derivatives have received increased advocacy. The modular assembly of these molecules, which can be controlled at a molecular level, presents a flexible platform for the endowment of bespoke biomaterial properties. In this review, various elastin-like recombinamer–based porous biomaterials for both soft and hard tissue applications are discussed and their current and future applications evaluated.

Dermo-epidermal equivalents based on plasma-derived fibrin hydrogels have been extensively studied for skin engineering. However, they showed rapid degradation and contraction over time and low mechanical properties which limit their reproducibility and lifespan. In order to achieve better mechanical properties, elasticity and biological properties, we incorporated a elastin-like recombinamer (ELR) network, based on two types of ELR, one modified with azide (SKS-N₃) and other with cyclooctyne (SKS-Cyclo) chemical groups at molar ratio 1:1 at three different SKS (serine-lysine-serine sequence) concentrations (1, 3, and 5 wt.%), into plasma-derived fibrin hydrogels. Our results showed a decrease in gelation time and contraction, both in the absence and presence of the encapsulated human primary fibroblasts (hFBs), higher mechanical properties and increase in elasticity when SKSs content is equal or higher than 3%. However, hFBs proliferation showed an improvement when the lowest SKS content (1 wt.%) was used but started decreasing when increasing SKS concentration at day 14 with respect to the plasma control. Proliferation of human primary keratinocytes (hKCs) seeded on top of the hybrid-plasma hydrogels containing 1 and 3% of SKS showed no differences to plasma control and an increase in hKCs proliferation was observed for hybrid-plasma hydrogels containing 5 wt.% of SKS. These promising results showed the need to achieve a balance between the reduced contraction, the better mechanical properties and biological properties and indicate the potential of using this type of hydrogel as a testing platform for pharmaceutical products and cosmetics, and future work will elucidate their potential.

The partial substitution of collagen with elastin-like recombinamers in tubular gels improves cell-mediated remodeling, elastic moduli and strength during maturation.

Three novel fullerothioureas derived from natural valine, phenylalanine, and tert‐leucine have been prepared by Prato's reaction of [60]fullerene and the corresponding aldehydes. These hybrids have been used as organocatalysts in a typical stereoselective nitro‐Michael addition reaction under homogeneous and neat conditions. The catalysts are easily recoverable by filtration, and are recyclable for at least five times. The addition products were obtained in excellent yields and stereoselectivities by using catalyst loadings of as low as 0.5 mol‐%.

The development of techniques for fabricating vascular wall models will foster the development of preventive and therapeutic therapies for treating cardiovascular diseases. However, the physical and biological complexity of vascular tissue represents a major challenge, especially for the design and the production of off-the-shelf biomimetic vascular replicas. Herein, we report the development of a biocasting technique that can be used to replicate the tunica adventitia and the external elastic lamina of the vascular wall. Type I collagen embedded with neonatal human dermal fibroblast (HDFn) and an elastic click cross-linkable, cell-adhesive and protease-sensitive elastin-like recombinamer (ELR) hydrogel were investigated as readily accessible and tunable layers to the envisaged model. Mechanical characterization confirmed that the viscous and elastic attributes predominated in the collagen and ELR layers, respectively. In vitro maturation confirmed that the collagen and ELR provided a favorable environment for the HDFn viability, while histology revealed the wavy and homogenous morphology of the ELR and collagen layer respectively, the cell polarization towards the cell-attachment sites encoded on the ELR, and the enhanced expression of glycosaminoglycan-rich extracellular matrix and differentiation of the embedded HDFn into myofibroblasts. As a complementary assay, 30% by weight of the collagen layer was substituted with the ELR. This model proved the possibility to tune the composition and confirm the versatile character of the technology developed, while revealing no significant differences with respect to the original construct. On-demand modification of the model dimensions, number and composition of the layers, as well as the type and density of the seeded cells, can be further envisioned, thus suggesting that this bi-layered model may be a promising platform for the fabrication of biomimetic vascular wall models.