The purpose of this study was to compare the clinical results of guided tissue regeneration(GTR) using a resorbable barrier manufactured from an copolymer of polylactic acid (PLA) and polylactic-glycolic acid(PLGA) with those of nonresorbable ePTFE bdmer. Thirty two patients(25 to 59 years old) with one radiographically evident intrabony lesion of probing depth > or =6mm participated in a Gmonth controlled clinical trial. The subjects were randomly divided into three independent groups. The fist group(n=8) received a ePTFE barrier. The second group (n=12) received a resorbable PLA/PLGA barrier. The third group (n=12) received a resorbable PLA/PLGA barrier combined with an alloplastic bone graft. Plaque index (PI), gingival index(GI), probing depth(PD) , gingival recession, clinical attachment level(CAL), and tooth mobility were recorded prior to surgery and at 3,6 months postsurgery. Statistical tests used to analyze these data included independent t-test, paired t-test, one-way ANOVA. The results were as follows : 1. Probing depth was significantly reduced in all groups at 3,6 months postsurgery and there were not significant differences between groups. 2. Clinical attachment level was significantly increased in all groups at 3, 6 months postsurgery and there were not significant differences between groups. 3. There were not signifiicant differences in probing depth, clinical attachment level, gingival recession, tooth mobility between second group (PLA/PLGA barrier) and third group (PLA/RLGA barrier combined with alloplastic bone graft) 4. Tooth mobility was not significantly increased in all groups at 3,6 months postsurgery and there were not significant differences between groups. In conclusion, PLA/PLGA resorbable barrier has similar clinical potential to ePTFE barrier in GTR procedure of intrabony pockets under the present protocol.
Gingival Recession ; Guided Tissue Regeneration* ; Humans* ; Methods ; Tooth Mobility ; Transplants

OBJECTIVETo accelerate distraction osteogenesis by utilizing guided bone regeneration technique, and to improve the automatic process of canine segmental mandibular reconstruction by elasticity distraction osteogenesis using shape memory metal alloy distractor.

METHODSAdult hybrid canines were used. Osteotomy was performed to remove a bone segment of 2.5-4.0 cm in one side of the mandible. Mandibular fixation devices and shape memory metal alloy distractor were secured according to the principles of bi-focal distraction technique. A piece of ePTFE membrane was sutured to cover the buccal side of bone defect and osteotomy gap of transport disc, where the periosteum was peeled for exposing mandible in operation. Then the incisions were totally closed. The canines were sacrificed 3 months later to harvest the mandibles for morphological observation and measurement of bone density and intensity.

RESULTSThe shape memory metal alloy distractor performed distraction osteogenesis automatically and reconstructed the mandibles with bone defect. A regenerated bone segment of 1.5-2.0 cm was formed in the compression region between transport disc and contralateral mandibular end. The new bone in both of distraction and compression regions had similar height and thickness with normal mandible. Moreover the new bone density and intensity were rather satisfied.

CONCLUSIONSMembrane guided bone regeneration can avoid bone synthesis commonly caused by cicatrization of soft tissue in the bone defect, and accelerate ossification and maturation of new generated bone.

Animals ; Bone Regeneration ; Dogs ; Guided Tissue Regeneration ; Mandible ; pathology ; surgery ; Nickel ; Osteogenesis, Distraction ; instrumentation ; methods ; Titanium

In the present study, porous PCL (poly (epsilon-caprolactone)) scaffolds were prepared through a melted extrusion manufacturing (MEM) machine, and carboxylate groups were formed on the surfaces of specimen by hydrolyzation with NaOH aqueous solutions. Apatite precursor was introduced on the surfaces of specimens with CaCl2 and K2 HPO4 under vacuum condition, and mineralization study was applied to these specimens. The results showed that the hydrophilicity of PCL surface was improved with the introduction of carboxylate groups, and the contact angle of surface was decreased to 26.52 degrees. A dense and uniform bone-like layer was confirmed to be formed on the surface of Ca-P treated specimens after mineralizing for less than 24 h in SBF by SEM and EDAX.
Biocompatible Materials ; chemistry ; Bone Regeneration ; Guided Tissue Regeneration ; methods ; Humans ; Polyesters ; chemical synthesis ; Tissue Engineering ; Tissue Scaffolds ; chemistry

The field of tissue engineering has made steady progress in translating various tissue applications. Although the classical tissue engineering strategy, which involves the use of culture-expanded cells and scaffolds to produce a tissue construct for implantation, has been validated, this approach involves extensive cell expansion steps, requiring a lot of time and laborious effort before implantation. To bypass this ex vivo process, a new approach has been introduced. In situ tissue regeneration utilizes the body's own regenerating capacity by mobilizing host endogenous stem cells or tissue-specific progenitor cells to the site of injury. This approach relies on development of a target-specific biomaterial scaffolding system that can effectively control the host microenvironment and mobilize host stem/progenitor cells to target tissues. An appropriate microenvironment provided by implanted scaffolds would facilitate recruitment of host cells that can be guided to regenerating structural and functional tissues.
Animals ; Guided Tissue Regeneration/*methods ; Humans ; Stem Cell Transplantation/*methods ; Stem Cells/*cytology/metabolism ; Tissue Engineering/methods ; Tissue Scaffolds

Tissue engineering technology provides a new method to repair ill tissue and worn-out organs. In tissue engineering, scaffolds play an important role in supporting cell growth, inducing tissue regeneration, controlling tissue structure and releasing active factor. In the last decade, electrospinning technology developed rapidly and opened vast application fields for scaffolds. In this review, we summarized the technological conditions of electrospinning for scaffolds, the study of electrospun fiber scaffolds applied in tissue cell cultivation, and some new directions of electrospinning technology for scaffolds. We also addressed development directions of electrospinning research for scaffolds.
Absorbable Implants ; Biocompatible Materials ; chemistry ; Electrochemistry ; methods ; Guided Tissue Regeneration ; Tissue Engineering ; instrumentation ; methods ; Tissue Scaffolds ; chemistry

Replacing urethral tissue with functional scaffolds has been one of the challenging problems in the field of urethra reconstruction or repair over the last several decades. Various scaffold materials have been used in animal studies, but clinical studies on use of scaffolds for urethral repair are scarce. The aim of this study was to review recent animal and clinical studies on the use of different scaffolds for urethral repair, and to evaluate these scaffolds based on the evidence from these studies. PubMed and OVID databases were searched to identify relevant studies, in conjunction with further manual search. Studies that met the inclusion criteria were systematically evaluated. Of 555 identified studies, 38 were included for analysis. It was found that in both animal and clinical studies, scaffolds seeded with cells were used for repair of large segmental defects of the urethra, such as in tubular urethroplasty. When the defect area was small, cell-free scaffolds were more likely to be applied. A lot of pre-clinical and limited clinical evidence showed that natural or artificial materials could be used as scaffolds for urethral repair. Urinary tissue engineering is still in the immature stage, and the safety, efficacy, cost-effectiveness of the scaffolds are needed for further study.
Animals ; Guided Tissue Regeneration ; adverse effects ; methods ; Humans ; Tissue Engineering ; methods ; Tissue Scaffolds ; adverse effects ; chemistry ; Urethra ; surgery

Three-dimensional cell scaffolds play an important role in tissue engineering. They can modulate cell response and guide the regeneration of tissues. Injectable scaffolds can mimic the chemical and physical environments of natural extracellular matrix, and can be easily applied in clinic with the merits of minor or nonsurgical operations. Hence, special care should be given to the use of this kind of scaffolds in tissue engineering hydrogels, and composites with other fillers have been used as a basic component to construct the injectable scaffolds. Most of these injectable scaffolds are applied to repair bone and cartilage. Experimental results have development of the injectable scaffolds in recent years. The advantages and disadvantages are discussed with the development of the injectable scaffolds in recent years. The advantages and disadvantages are discussed with the suggestions for future development.
Absorbable Implants ; Biocompatible Materials ; Bone and Bones ; physiology ; Cartilage ; physiology ; Guided Tissue Regeneration ; Humans ; Hydrogels ; Tissue Engineering ; methods ; Tissue Scaffolds

Guided bone regeneration (GBR) is a technique utilizing membrane as a physical barrier to separate and create a secluded space around the bone defect. This permits the regeneration of bone tissue and reduces the fast growth of connective tissues. Moreover, GBR membranes sustain a protected space during tissue-healing period. Nowadays there are many kinds of GBR membranes used in study and practice, and each of them has its characteristic merits and defects respectively. This paper reviews the studies of GBR membranes, with the emphases on the structure and properties of membrane materials as well as their biological functions.
Biocompatible Materials ; Guided Tissue Regeneration ; methods ; trends ; Humans ; Membranes, Artificial ; Polytetrafluoroethylene ; chemistry ; Silicone Gels ; chemistry ; Tissue Engineering ; methods ; Titanium ; chemistry

Through Hydroxyl (-OH) reacting with isocyanate group (-NCO), 13 Wt% nano-hydroxyapatite (n-HA)/polyurethane (PU) composite guided bone regeneration membrane was synthesized by use of solvent evaporation method. Its surface character was analyzed by XRD, IR, TG, contact angle, water absorption, elongation and combustion test and SEM. The results indicate that nano-HA/PU has good homogeneity,the interface between the inorganic mineral and organic polymer is optimized to create proper combination; that n-HA crystals are similar to the apatite crystals in natural bone, HA/PU composite membrane has good hydrophilicity mechanical behavior; and that many pores are observed on the membrane which help cells' metabolism. So the HA/PU composite membrane, thus prepared, has the potential for use in guided bone regeneration and tissue engineering.
Biocompatible Materials ; chemistry ; Bone Regeneration ; Durapatite ; chemistry ; Guided Tissue Regeneration ; methods ; Nanocomposites ; chemistry ; Polyurethanes ; chemistry ; Tissue Engineering ; methods ; Tissue Scaffolds ; chemistry

OBJECTIVETo observe the effects of cells and scaffolds tissue engineering on the periodontal regeneration, and to evaluate the feasibility of nano-Hap-collagen (nHAC) as the scaffold material for periodontal tissue engineering.

METHODSDog autogenous periodontal ligament cells (PDLCs) cultured in vitro were collected and seeded on the three-dimensional framework of nHAC. The cell growth in the scaffolds was observed by scanning electron microscope. And then the PDLCs-nHAC composites were transplanted into man-made periodontal defects, and the groups filled with nothing or filled only with nHAC were the controls. The dogs were sacrificed after 8 weeks and the periodontal regeneration was observed histologically.

RESULTSScanning electron microscope showed the porous structure of nHAC and the eugonic growth of cells in the nHAC scaffolds. The histological observation showed that the PDLCs-nHAC groups exhibited more new bone, new periodontal ligament and new cementum occupying the majority of the defects than the control groups, and the epitheliums were not observed.

CONCLUSIONSPeriodontal regeneration could be enhanced by the cells and scaffolds tissue engineering, and the PDLCs and nHAC could be used as the seed cell and the scaffold material for periodontal tissue engineering.

Animals ; Biocompatible Materials ; Cells, Cultured ; Dogs ; Guided Tissue Regeneration ; Male ; Periodontal Attachment Loss ; surgery ; Periodontal Ligament ; cytology ; Regeneration ; Replantation ; methods ; Tissue Engineering ; methods ; Transfection