In this work, we fabricated injectable bone substitutes modified with the addition of bioactive glass powders synthesized via ultrasonic energy-assisted hydrothermal method to the calcium phosphate-based bone cement to improve its biocompatibility. The injectable bone substitutes was initially composed of a powder component (tetracalcium phosphate, dicalcium phosphate dihydrate and calcium sulfate dehydrate) and a liquid component (citric acid, chitosan and hydroxyl-propyl-methyl-cellulose) upon which various concentrations of bioactive glass were added: 0%, 10%, 20% and 30%. Setting time and compressive strength of the injectable bone substitutes were evaluated and observed to improve with the increase of bioactive glass content. Surface morphologies were observed via scanning electron microscope before and after submersion of the samples to simulated body fluid and increase in apatite formation was detected using x-ray diffraction machine. In vitro biocompatibility of the injectable bone substitutes was observed to improve with the addition of bioactive glass as the proliferation/adhesion behavior of cells on the material increased. Human gene markers were successfully expressed using real time-polymerase chain reaction and the samples were found to promote cell viability and be more biocompatible as the concentration of bioactive glass increases. In vivo biocompatibility of the samples containing 0% and 30% bioactive glass were evaluated using Micro-CT and histological staining after 3 months of implantation in male rabbits' femurs. No inflammatory reaction was observed and significant bone formation was promoted by the addition of bioactive glass to the injectable bone substitute system.

Three dimensional porous scaffolds composed of various ratios of polycaprolactone and poly(L-lactic acid) (PLLA) were prepared using salt leaching method for bone regeneration applications. Surfaces of the scaffolds were visualized using scanning electron microscope (SEM) and the combination of the polymers was confirmed by FT-IR. Addition of PLLA increased the porosity and pore sizes of the scaffolds and also the scaffolds' compressive strength initially. Osteoblast-like cells were used and it was found that the samples' cell biocompatibility was further promoted with the increase in PLLA content as observed via cell proliferation assays using MTT, gene expression with RT-PCR, and micrographs from SEM and confocal microscopy. Samples were then implanted into male rabbits for 2 months, and histological staining and micro-CT histomorphometry show that new bone formations were detected in the site containing the implants of the scaffolds and that bone regeneration was further promoted with the increased concentration of PLLA in the scaffold.

The main objective of this study was to fabricate a controlled drug delivery which is simultaneously effective for bone regeneration. We have encapsulated simvastatin, which enhances osteoblastic activity, in the poly (lactic-co-glycolic acid) microspheres. Loading of these microspheres inside the spongy scaffold of biphasic calcium phosphate with the help of Gelatin (Gel) hydrogel controls the delivery of the drug, and ensures a more favorable drug release profile. As a result, some significant benefits have been achieved, such as higher mechanical strength, excellent biocompatibility in in vitro experiments. For determining the characteristics of the composite scaffold, several analysis, such as scanning electron microscope, EDX, X-ray diffraction, FT-IR, and porosity were carried out. The in vitro drug release profile clearly indicates that simvastatin release from the microsphere was more controlled and prolonged after loading in the scaffold. Biocompatibility was certainly higher for the final composite scaffold compared to drug unloaded scaffold, as assessed through MTT assay and Confocal imaging with MC3T3-E1 pre-osteoblast cells. Cell attachment and proliferation were certainly higher in the presence of drug loaded microspheres. Bone remodeling gene and protein expression were observed by real-time polymerase chain reaction and Western blot respectively. Simvastatin loaded scaffold exhibited the best results in every determination which was carried out.

This study evaluated the effectiveness of carboxymethyl cellulose (CMC) hydrogel as a dental gel in delivering hydroxyapatite (HAp) to dentine tubules and reducing/eliminating dental hypersensitivity. The hydrogel was prepared by mixing solutions of CMC/ glycerol and distilled water/sorbitol then modified to contain 0%, 10%, 20% and 30% HAp. The pH of the hydrogels decreased and viscosity increased with increasing HAp content. A viability assay was performed to determine the cytotoxicity of the hydrogel samples and proliferation/adhesion behavior of cells cultured on the hydrogel surface. The samples promoted cell proliferation and became more biocompatible with the addition of HAp. Dentin discs were prepared and then treated with the fabricated hydrogels. Occlusion of the dentine tubules was observed by scanning electron microscopy before and after treatment. Blocking of the dentin tubules was markedly affected by the addition of HAp to the hydrogel samples that can result in possible reduction or elimination of hypersensitivity.

This study aims to investigate on the effect of the addition of polyvinylphosphonic acid (PVPA) on the material properties and biocompatibility of a polyvinyl alcohol (PVA) polymer tissue engineering scaffold fabricated by electrospinning process. Stabilization of the membranes was carried out by heat application. Fourier transform infrared spectroscopy confirmed the presence of PO bonds and P–OH bonds and increase in the atomic percentage of phosphorus in Energy Dispersive Spectroscopy (EDS) indicated successful incorporation of PVPA to the PVA. Scanning electron microscope fiber morphology and microstructure showed that addition of PVPA reduced the average fiber diameter of the scaffold. After 1 hr of phosphate buffered saline immersion, scaffolds were observed to swell to almost 200% of their original weight. Increased tensile strength was observed at 0.1% PVPA addition but reduced values were observed when the concentration was greater than 0.1%. Cytocompatibility was examined with M3CT3‐E1 preosteoblast cells through cell viability after exposure to extract solutions and Live/Dead cell staining. Cell proliferation was quantified by MTT assay; cell adhesion was visualized by scanning electron microscope and confocal microscopy images. Bone regeneration was also observed and quantified using histomorphometric analysis and histological staining methods after implantation in rat calvarium for 4 weeks. Copyright © 2013 John Wiley & Sons, Ltd.