Because bone-associated diseases are increasing, a variety of tissue engineering approaches with bone regeneration purposes have been proposed over the last years. Bone tissue provides a number of important physiological and structural functions in the human body, being essential for hematopoietic maintenance and for providing support and protection of vital organs. Therefore, efforts to develop the ideal scaffold which is able to guide the bone regeneration processes is a relevant target for tissue engineering researchers. Several techniques have been used for scaffolding approaches, such as diverse types of biomaterials. On the other hand, metallic biomaterials are widely used as support devices in dentistry and orthopedics, constituting an important complement for the scaffolds. Hence, the aim of this review is to provide an overview of the degradable biomaterials and metal biomaterials proposed for bone regeneration in the orthopedic and dentistry fields in the last years.

The aim of this study has been to fabricate a hybrid electrospun nanofibrous scaffold composed of poly(lactic-co-glycolic) acid (PLGA)/fibrin polymers to be used as a skin substitute and analyze its physical and biological properties. Fibrin was obtained from rat blood plasma, characterized and solubilized in formic acid. The final electrospinning solution concentration was 40% PLGA (w/v) and 1% fibrin (w/v). To improve spinnability, 3% PEG (w/v) was added. The scaffolds were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Water contact angle, maximum elongation, thermal stability, degree of swelling, blood compatibility, cytotoxicity and cell viability were analyzed. The characterization by SEM showed randomly oriented nanofibers with a mean diameter of 639.8 ± 241.8 nm for the PLGA/fibrin and 1051.0 ± 290.2 nm for the PLGA. FTIR spectra confirmed the presence of fibrin in the mats. Fibrin incorporation reduced the water contact angle from 118.9 ± 2.9 to 111.1 ± 2.8. The fibrin increased tensile strength and decreased elongation at break. The scaffolds demonstrated blood compatibility and fibrin incorporation improved cell adhesion and viability when direct and indirect MTT analyses were carried out. Thus, it can be concluded that the PLGA/fibrin mat is a promising material for use as a skin substitute.

Hybrid scaffolds from natural and synthetic polymers have been widely used due to the complementary nature of their physical and biological properties. The aim of the present study, therefore, has been to analyze in vivo a bilayer scaffold of poly(lactide-co-glycolide)/fibrin electrospun membrane and fibrin hydrogel layer on a rat skin model. Fibroblasts were cultivated in the fibrin hydrogel layer and keratinocytes on the electrospun membrane to generate a skin substitute. The scaffolds without and with cells were tested in a full-thickness wound model in Wistar Kyoto rats. The histological results demonstrated that the scaffolds induced granulation tissue growth, collagen deposition and epithelial tissue remodeling. The wound-healing markers showed no difference in scaffolds when compared with the positive control. Activities of antioxidant enzymes were decreased concerning the positive and negative control. The findings suggest that the scaffolds contributed to the granulation tissue formation and the early collagen deposition, maintaining an anti-inflammatory microenvironment.