Clinical, volumetric and densitometric evaluation of tissue engineered constructs for secondary alveolar cleft reconstruction: A randomized clinical trial.

The objective of this study was to assess the efficacy of tissue engineered (TE) constructs compared to the standard autogenous anterior iliac crest (AIC) bone graft in secondary maxillary alveolar cleft reconstruction. This clinical trial was registered on (clinical trials.gov); the trial registry number is: NCT03563495. Patients with unilateral alveolar clefts were allocated on the basis of simple randomization. Selected patients were randomly divided into two equal groups: the AIC group (control) received autogenous particulate bone graft from anterior iliac crest, whereas the TE group received tissue engineered construct. Assessment included the newly formed bone volume and density at the grafted cleft sites, which were measured immediately, 6 and 12 months postoperatively on axial computed tomograms. The study population included 10 patients; each group comprised 5 patients. There was no statistically significant difference between the 2 groups regarding the mean volume of the newly formed bone (p = 0.91 at 6 months, p = 0.994 at 1 year) and the mean density of the newly formed bone (p = 0.364 at 6 months, p = 0.073 at 1 year). However, there was a significant increase of TE graft density from 6 months to 1 year (p = 0.048). Within the limitations of the study it seems that the tissue engineered construct (collagen/osteogenically differentiated bone marrow-derived mesenchymal stem cells) might be an alternative to autogenous bone for unilateral secondary alveolar cleftgrafting.

Injectable TEMPO-oxidized nanofibrillated cellulose/biphasic calcium phosphate hydrogel for bone regeneration.

Nanofibrillated cellulose, obtained from rice straw agricultural wastes was used as a substrate for the preparation of a new injectable and mineralized hydrogel for bone regeneration. Tetramethyl pyridine oxyl (TEMPO) oxidized nanofibrillated cellulose, was mineralized through the incorporation of a prepared and characterized biphasic calcium phosphate at a fixed ratio of 50 wt%. The TEMPO-oxidized rice straw nanofibrillated cellulose was characterized using transmission electron microscopy, Fourier transform infrared, and carboxylic content determination. The injectability and viscosity of the prepared hydrogel were evaluated using universal testing machine and rheometer testing, respectively. Cytotoxicity and alkaline phosphatase level tests on osteoblast like-cells for in vitro assessment of the biocompatibility were investigated. Results revealed that the isolated rice straw nanofibrillated cellulose is a nanocomposite of the cellulose nanofibers and silica nanoparticles. Rheological properties of the tested materials are suitable for use as injectable material and of nontoxic effect on osteoblast-like cells, as revealed by the positive alkaline phosphate assay. However, nanofibrillated cellulose/ biphasic calcium phosphate hydrogel showed higher cytotoxicity and lower bioactivity test results when compared to that of nanofibrillated cellulose.