In vitro and in vivo proves of concept for the use of a chemically cross-linked poly(ester-urethaneurea)scaffold as an easy handling elastomeric biomaterial for bone regeneration

Bone loss can occur as a result of various pathologies,traumas and injuries and poor bone healing leads to functionally debilitating condition,loss of self-sufficiency and deterioration in life quality.Given the increasing incidence of facial trauma and the emergence of new procedural techniques,advanced scaffolds are currently developed as substitutes for bone tissue engineering.In this study,we investigated the capability of a chemically cross-linked e-caprolactone-based poly(esterurethane-urea)(PCLU)scaffold to support bone regeneration.In vitro assays demonstrated that PCLU scaffolds could be colonized by cells through direct cell seeding and cell migration from outside to scaffold inside.Moreover,PCLU scaffolds could provide a suitable environment for stem cells proliferation in a 3D spatial arrangement,and allowed osteogenic differentiation under appropriate induction.In vivo results revealed the osteogenic properties of PCLU scaffolds through a drilled-hole femoral bone defect repair improvement in rats.Using histology and microtomography analysis,we showed that PCLU scaffolds fit well the bone cavity and were eventually entrapped between the newly formed trabeculae.Finally,no sign of inflammation or rejection was noticed.We envision that PCLU scaffolds can provide the clinicians with a substitute having appropriate characteristics for the treatment of bone defects.

Heparan-mimetics:Potential agents of tissue regeneration for bone and periodontal therapies

Heparan sulfate glycosaminoglycans are key players of tissue repair and can be regarded as useful compounds for regenerative medicines.Unfortunately,their therapeutic uses face many technical,industrial,and regulatory hurdles due to their animal origin.So,some non-animal sulfated polysaccharides mimic heparan sulfate properties and offer interesting solutions to replace them.Among them,dextran derivatives,seaweed polysaccharides,or marine bacterial polysaccharides are the best known and have demonstrated their pro-regenerative capabilities by promoting both extracellular matrix structuring and angiogenesis and limiting degenerative processes such as inflammatory cell migration or tissue proteolysis.These polysaccharides have also shown their ability to specifically promote osteoblastic differentiation and bone wound healing.Furthermore,recent works shows that heparan-mimetics can be used as an additive to improve the cytocompatibility of bone substitutes commonly used in periodontal surgery.The use of these polysaccharides can be regarded as a clever approach to improve the biointegration of bone substitutes.