Problems: Tissue engineering (TE) is one of the modern strategies to provide a functional biological tissue equivalent to restore or improve the function of human tissues that lost by disease, traumatic events, or congenital abnormalities. Some essential factors in TE are tissue type and appropriate scaffold. suitable influence on cell viability and proliferation is One of the most important characteristics of a appropriate scaffold for tissue engineering. The purpose of this research was to comparative evaluation of adipose derived stem cells (ADSCs) proliferation rate and their viability on the five different scaffolds. Experimental approach: six different scaffolds were prepared including Alginate, Poly Lactic Glycolic Acid (PLGA), Fibrin glue (FG), Inactive Platelet- Rich Plasma (IPRP), Active Platelet- Rich Plasma (APRP) and Hydroxyapatite/ β

The Design of Scaffolds for Use in Tissue Engineering

Bone is the most implanted tissue after blood. The major solid components of human bone are collagen (a natural polymer, also found in skin and tendons) and a substituted hydroxyapatite (a natural ceramic, also found in teeth). Although these two components when used separately provide a relatively successful mean of augmenting bone growth, the composite of the two natural materials exceeds this success. This paper provides a review of the most common routes to the fabrication of collagen (Col) and hydroxyapatite (HA) composites for bone analogues. The regeneration of diseased or fractured bones is the challenge faced by current technologies in tissue engineering. Hydroxyapatite and collagen composites (Col-HA) have the potential in mimicking and replacing skeletal bones. Both in vivo and in vitro studies show the importance of collagen type, mineralisation conditions, porosity, manufacturing conditions and crosslinking. The results outlined on mechanical properties, cell culturing and de-novo bone growth of these devices relate to the efficiency of these to be used as future bone implants. Solid free form fabrication where a mould can be built up layer by layer, providing shape and internal vascularisation may provide an improved method of creating composite structures.

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Collagen-hydroxyapatite composites for hard tissue repair.

In vivo behavior of three different injectable hydraulic calcium phosphate cements.

Functionally graded electrospun polycaprolactone and beta-tricalcium phosphate nanocomposites for tissue engineering applications.

After five decades characterized by empiricism and several pitfalls, some of the basic mechanisms of action of ozone in pulmonary toxicology and in medicine have been clarified. The present knowledge allows to understand the prolonged inhalation of ozone can be very deleterious first for the lungs and successively for the whole organism. On the other hand, a small ozone dose well calibrated against the potent antioxidant capacity of blood can trigger several useful biochemical mechanisms and reactivate the antioxidant system. In detail, firstly ex vivo and second during the infusion of ozonated blood into the donor, the ozone therapy approach involves blood cells and the endothelium, which by transferring the ozone messengers to billions of cells will generate a therapeutic effect. Thus, in spite of a common prejudice, single ozone doses can be therapeutically used in selected human diseases without any toxicity or side effects. Moreover, the versatility and amplitude of beneficial effect of ozone applications have become evident in orthopedics, cutaneous, and mucosal infections as well as in dentistry.

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The ozone paradox: ozone is a strong oxidant as well as a medical drug.

The postural stability control and gait pattern of idiopathic scoliosis adolescents.

With advances in ceramics technology, calcium phosphate bioceramics have been applied as bone substitutes for several decades. The focus of this work is to elucidate the biocompatibility of the particulates of various calcium phosphate cytotoxicities. Four different kinds of calcium phosphate powders, including beta-tricalcium phosphate (beta-TCP), hydroxyapatite (HA), beta-dicalcium pyrophosphate (beta-DCP), and sintered beta-dicalcium pyrophosphate (SDCP), were tested by osteoblast cell culture. The results were analyzed by cell count, concentration of transforming growth factor-beta 1 (TGF-beta 1), alkaline phosphatase (ALP), and prostaglandin E2 (PGE2) in culture media. The changes were most significant when osteoblasts were cultured with beta-TCP and HA bioceramics. The changes in cell population of the beta-TCP and HA were quite low in the first 3 days, then increased gradually toward the seventh day. The changes in TGF-beta 1 concentration in culture medium inversely related to the changes in cell population. The ALP titer in the culture media of the beta-TCP and HA were quite high in the first 3 days, then decreased rapidly between the third and seventh days. The concentrations of PGE2 in the culture media tested were quite high on the first day, decreased rapidly to the third day, and then gradually until the seventh day. The changes in the beta-DCP and SDCP were quite similar to those of HA and beta-TCP but much less significant. We conclude that HA and beta-TCP have an inhibitory effect on the growth of osteoblasts. The inhibitins effects of the HA and beta-TCP powders on the osteoblast cell cultures possibly are mediated by the increased synthesis of PGE2.

The effects of calcium phosphate particles on the growth of osteoblasts

During recent years, sintered dicalcium phosphate (SDCP) has been shown to be an effective artificial bone filler for repairing bone defects. The goal of this study was to elucidate the effect of SDCP particle size on osteoblasts. Osteoblasts were mixed and cultured with various sized SDCP particles (0.5-3.0, 37-63, 177-250, and 420-841 microns) for 1 h, 3 h, 1 day, 3 days, and 7 days and then analyzed. The results show that the adding of smaller sized SDCP particles (0.5-3.0 and 37-63 microns) into osteoblast culture can significantly affect the cell counts of osteoblasts. The secretion of transforming growth factor-beta 1, alkaline phosphatase, and prostaglandin E2 in culture medium increased significantly. The changes were most significant and persisted longer in smaller particle groups. Small sintered dicalcium phosphate particles can inhibit the proliferation of the osteoblasts. The inhibitory effects of the smaller sized SDCP particles on the osteoblasts were mediated by the promotion of osteoblast differentiation and the increased synthesis of prostaglandin E2.

The effect of sintered β-dicalcium pyrophosphate particle size on newborn wistar rat osteoblasts

Although ischemic injury to skeletal muscle is a matter of great clinical importance, relatively little is known about the mechanisms which determine systemic responses. One purpose of this study is to elucidate the systemic antioxidant status following an episode of acute ischemic limb injury and subsequent reperfusion.Twelve New Zealand white rabbits were used in this study. After the animals were anesthetized, an ischemic insult was created in the right hind limb for twelve hours, followed by four hours of reperfusion. Several series of blood samples were obtained. At the end of the experiment, the animals were killed and necropsies undertaken in order to evaluate the antioxidant status of various visceral organs.The results link ischemia and reperfusion injury to a significant decline in antioxidative activity in various tissues. The weakening in antioxidant status after ischemic limb injury was most pronounced in the heart tissue, followed in descending order by the spleen, skeletal muscle, lung, liv...

Yi Shiong Hang

Papers

The postural stability control and gait pattern of idiopathic scoliosis adolescents.

The effects of calcium phosphate particles on the growth of osteoblasts

The effect of sintered β-dicalcium pyrophosphate particle size on newborn wistar rat osteoblasts

Antioxidant status following acute ischemic limb injury: a rabbit model.

Scavenging effect of benzophenones on the oxidative stress of skeletal muscle cells.