The use of bone grafts is the standard to treat skeletal fractures, or to replace and regenerate lost bone, as demonstrated by the large number of bone graft procedures performed worldwide. The most common of these is the autograft, however, its use can lead to complications such as pain, infection, scarring, blood loss, and donor-site morbidity. The alternative is allografts, but they lack the osteoactive capacity of autografts and carry the risk of carrying infectious agents or immune rejection. Other approaches, such as the bone graft substitutes, have focused on improving the efficacy of bone grafts or other scaffolds by incorporating bone progenitor cells and growth factors to stimulate cells. An ideal bone graft or scaffold should be made of biomaterials that imitate the structure and properties of natural bone ECM, include osteoprogenitor cells and provide all the necessary environmental cues found in natural bone. However, creating living tissue constructs that are structurally, functionally and mechanically comparable to the natural bone has been a challenge so far. This focus of this review is on the evolution of these scaffolds as bone graft substitutes in the process of recreating the bone tissue microenvironment, including biochemical and biophysical cues.

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An efficient electrochemical transducer matrix for biosensing devices requires specific characteristics, such as fast electron transfer, stability, high surface area, biocompatibility, and presence of specific functional groups, to facilitate biomolecule attachment. We demonstrate the fabrication of an electrochemical immunosensor based on a highly stable gold nanoparticles-reduced graphene oxide (AuNPs-rGO) composite material as a transducer matrix for label-free and noninvasive detection of salivary oral cancer biomarker interleukin-8 (IL8). The synergy between rGO and AuNPs allowed the immunosensor to exhibit fast response and high sensitivity due to the improved electron transfer behavior of the composite. The immunosensor shows very fast detection (9 min) of IL8 and high sensitivity with an experimental linear dynamic range of 500 fg mL to 4 ng mL and a detection limit of 72.73 ± 0.18 pg mL. The fabricated immunosensor exhibits excellent specificity toward the detection of IL8 in human saliva samples. Furthermore, the reusability and stability up to 3 months of the immunosensor demonstrates the commercial potential of this nanoplatform for the detection of other biomarkers of clinical relevance.

Improvements in osteoconduction of implant biomaterials require focusing on the bone-implant interface, which is a complex multifactorial system. Surface topography of implants plays a crucial role at this interface. Nanostructured surfaces have been shown to promote serum protein adsorption and osteoblast adhesion when compared to microstructured surfaces for bone-implant materials. We studied the influence of the serum proteins fibronectin and vitronectin on the attachment and proliferation of osteoblasts onto nanostructured titania surfaces. Human fetal osteoblastic cells hFOB 1.19 were used as model osteoblasts and were grown on nanoporous TiO2 templates, using Ti6Al4V and commercially pure Ti substrates as controls. Results show a significant increase in cell proliferation on nanoporous TiO2 over flat substrates. Initial cell attachment data exhibited a significant effect by either fibronectin or vitronectin on cell adhesion at the surface of any of the tested materials. In addition, the extent of cell adhesion was significantly different between the nanoporous TiO2 and both Ti6Al4V and commercially pure Ti substrates, with the first showing the highest surface coverage. There was no significant difference on osteoblast attachment or proliferation between the presence of fibronectin or vitronectin using any of the material substrates. Taken together, these results suggest that the increase in osteoblast attachment and proliferation shown on the nanoporous TiO2 is due to an increase in the adsorption of fibronectin and vitronectin because of the higher surface area and to an enhanced protein unfolding, which allows access to osteoblast binding motifs within these proteins.

Heart disease remains one of the leading causes of death in industrialized nations with myocardial infarction (MI) contributing to at least one fifth of the reported deaths. The hypoxic environment eventually leads to cellular death and scar tissue formation. The scar tissue that forms is not mechanically functional and often leads to myocardial remodeling and eventual heart failure. Tissue engineering and regenerative medicine principles provide an alternative approach to restoring myocardial function by designing constructs that will restore the mechanical function of the heart. In this review, we will describe the cellular events that take place after an MI and describe current treatments. We will also describe how biomaterials, alone or in combination with a cellular component, have been used to engineer suitable myocardium replacement constructs and how new advanced culture systems will be required to achieve clinical success.