Of all biologic matrices, decellularized tissues have emerged as a promising tool in the field of regenerative medicine. Few empirical clinical studies have shown that Wharton’s jelly (WJ) of the human umbilical cord promotes wound closure and reduces wound-related infections. In this scope, we herein investigated whether decellularized (DC)-WJ could be used as an engineered biomaterial. In comparison with devitalized (DV)-WJ, our results showed an inherent effect of DC-WJ on Gram positive (S. aureus and S. epidermidis) and Gram negative (E. coli and P. aeruginosa) growth and adhesion. Although DC-WJ activated the neutrophils and monocytes in a comparable magnitude to DV-WJ, macrophages modulated their phenotypes and polarization states from the resting M0 phenotype to the hybrid M1/M2 phenotype in the presence of DC-WJ. M1 phenotype was predominant in the presence of DV-WJ. Finally, the subcutaneous implantation of DC-WJ showed total resorption after three weeks of implantation without any sign of foreign body reaction. These significant data shed light on the potential regenerative application of DC-WJ in providing a suitable biomaterial for tissue regenerative medicine and an ideal strategy to prevent wound-associated infections.

(1) Background: A suitable scaffold with adapted mechanical and biological properties for ligament tissue engineering is still missing. (2) Methods: Different scaffold configurations were characterized in terms of morphology and a mechanical response, and their interactions with two types of stem cells (Wharton’s jelly mesenchymal stromal cells (WJ-MSCs) and bone marrow mesenchymal stromal cells (BM-MSCs)) were assessed. The scaffold configurations consisted of multilayer braids with various number of silk layers (n = 1, 2, 3), and a novel composite scaffold made of a layer of copoly(lactic acid-co-(e-caprolactone)) (PLCL) embedded between two layers of silk. (3) Results: The insertion of a PLCL layer resulted in a higher porosity and better mechanical behavior compared with pure silk scaffold. The metabolic activities of both WJ-MSCs and BM-MSCs increased from day 1 to day 7 except for the three-layer silk scaffold (S3), probably due to its lower porosity. Collagen I (Col I), collagen III (Col III) and tenascin-c (TNC) were expressed by both MSCs on all scaffolds, and expression of Col I was higher than Col III and TNC. (4) Conclusions: the silk/PLCL composite scaffolds constituted the most suitable tested configuration to support MSCs migration, proliferation and tissue synthesis towards ligament tissue engineering.

In craniofacial bone defects, the promotion of bone volume augmentation remains a challenge. Finding strategies for bone regeneration such as combining resorbable minerals with organic polymers would contribute to solving the bone volume roadblock. Here, dicalcium phosphate dihydrate, chitosan and hyaluronic acid were used to functionalize a bone-side collagen membrane. Despite an increase in the release of inflammatory mediators by human circulating monocytes, the in vivo implantation of the functionalized membrane allowed the repair of a critical-sized defect in a calvaria rat model with de novo bone exhibiting physiological matrix composition and structural organization. Microtomography, histological and Raman analysis combined with nanoindentation testing revealed an increase in bone volume in the presence of the functionalized membrane and the formation of woven bone after eight weeks of implantation; these data showed the potential of dicalcium phosphate dihydrate, chitosan and hyaluronic acid to induce an efficient repair of critical-sized bone defects and establish the importance of thorough multi-scale characterization in assessing biomaterial outcomes in animal models.