As one of the most important strategies of no drug therapy,biomaterials have drawn extensive application in clinical use.Current animal tests and assays of cell level haven't reached the satisfying depth on the mechanism of biocompatibility and material-host interaction.As the typical method of post-genome era,proteomics contributed to investigation in the biomarker of diseases and the global theory of physiological function and drug effect.Along with the increase of the inquiry of biomaterial,high quality evaluation of bio-effects and the reliability is required.Utilizing proteomic method to study the dynamic variation of the whole proteins after contacting with certain biomaterial is an effective means to explore the direction of its further improvement.This review summarizes most representative studies on function and biocompatibility of biomaterials and focus on the application in dental implant materials,which indicate the significance of the combination of the biomaterials development and the progressive biology assay technique.

Objective:To study the effects of poly-DL-lactic acid(PDLLA) biomembrane in the repair of cleft hard palate. Methods:Thirty-two cleft palate patients, age 2.67 to 12.83 years old, were treated. The traditional surgical method was used to close the cleft soft palate, and the PDLLA biomembrane was implanted into the surgical gap between the periosteum and bone at the hard palate and fixed with suture to close the cleft hard palate. Clinical follow-up was conducted for 6 months.Results:Operations on all 32 patients were completed successfully.The average surgical time was not prolonged, and post-operative complication was not increased. Wound healing of soft palate, uvula and hard palate was uneventful with no incidence of fistula or dehiscence. Conclusion: PDLLA absorbable biomembrane can be used to repair cleft hard palate.

OBJECTIVE: Based on the overview of progress regarding seed cells and scaffolds for skin tissue engineering, to introduce the research of three dimensional nanofiber scaffolds prepared by electrospinning technique, and its application prospect in tissue engineered skin.DATA SOURCES: The databases of CNKI, Sciencedirect, and I.S.I were retrieved by the first author with key words of "tissue-engineering, skin, wound healing, seed cell, scaffold, electrospunning" in both Chinese and English from 1992 to 2009.DATA SELECTION: Major accomplishments of research on skin tissue engineering published in recent years.MAIN OUTCOME MEASURES: ①Papers related to treating skin destruction using tissue engineered materials. ②Articles correlative to seed cells and scaffold materials. ③Papers regarding electrospinning technique.RESULTS: The preparation of artificial skins is the research direction of tissue-engineered skin, in particular, studies regarding epidermal stem cells, bone marrow mesenchymal stem cells, hair follicle stem cells, and adipose-derived stem cells are attracted more attention. As tissue engineering, it is a key problems to prepare a scaffold to meet the needs of mechanical property,physical composition and biocompatibility. Scaffold materials comprise micrometer porous scaffold and nano-fiber scaffolds. The electrospinning technique is newly developed method for preparing nano-fiber scaffolds with the advantage of fast and convenience, and the scaffolds possess greater porosity, which not only benefit for the blood circulation and oxygen exchange,but also prevent the loss of water content and protein from wound surface.CONCLUSIONS: Tissue engineered skin is an important ingredient of regenerative medicine, seed cells and scaffold matrixes are two core problems that call for long term investigation. With the incessant development and integration among life sciences,nanotechnology and computer technology, marvelous progress has been achieved in the perspective of comprehending the interaction between seed cells, the mutual regulation mechanism and how the architecture and properties of scaffold materials affecting the regenerative procedures.

Smu. 260 encodes a putative protein of 200 residues in Streptococcus mutans, a primary pathogen for human dental caries. Smu. 260 was cloned into expression vector pET28a and expressed in good amount trom the E. coli strain BL21 (DE3). Smu.260 protein was purified to homogeneity in a two-step procedure of Ni2+ chelating and size exclusion chromatography. The purified protein exists in two forms, a dimer form about 46 ku with yellow color and a tetramer form without apparent color. Crystals were obtained from the dimer protein by hanging-drop vapor-diffusion method. The crystals diffracted to about 2.3 A resolution and belong to orthorhombic space group P212121 with cell dimensions of a = 89.88A, b = 90.91 A, c = 105.17 A. The asymmetric unit is expected to contain two dimers with solvent content of 53%.

The gene smu. 776 encodes a possible S-adenosylmethionine-dependent methyltransferase of 385 residues in Streptococcus mutans, a primary pathogen for human dental caries. The DNA fragment of smu.776 was cloned into pET28a and expressed in good amount from the E. coli strain BL21 (DE3). Smu.776 protein was purified to homogeneity in a two-step procedure ofNi2+ chelating and size exclusion chromatography. Crystals were obtained by hanging-drop vapor diffusion method and diffracted to 2.0 (A) resolution.The crystal belongs to orthorhombic space group C2 with cell dimension of a=168.47 (A), b= 50.66 (A), c=53.96 (A), β=104.22°. The asymmetric unit is expected to contain one molecule with solvent content of 51.3%.

The aim of this study was to evaluate the injectability, histocompatibility, function and other properties of the injectable bioactive bone repairing material of nano-hydroxyapatite and polyamide-66 (n-HA/PA66) composite. The XRD pattern, the relationship between the injectability and liquid-powder ratio, setting time and liquid-powder ratio, compressive strength and liquid-powder ratio were assessed. The size of the composite was determined to be 70 nm in length and 30 to 50 nm in width, and the molecular weight of polyamides-66 was 18000. The diameter of pores of the composite was about 200 to 400 micrometer. To evaluate the histocompatibility and function, 8 male dogs were studied with the injectable n-HA/PA66 composite implanted in the artificial defected alveolus of mandible on only one side to be compared with the intact alveolus on the other side. The specimens were taken at 4, 8, 12, 16 months after the implantation and the results were evaluated. The XRD pattern of the solidificated n-HA/PA66 composite was the same as the powdered n-HA/PA66 composite. The injectable n-HA/PA66 composite had a good injectability, 25 to 30 minutes setting time and about 37 MPa compressive strength when the liquid-powder ratio was 0.50. The healing of the gingiva was well at the implanted areas in all animals. The height of the repaired alveolar bone was obvious higher than that of the blank control. The earlier sign of ossification was histologically observed at 16 weeks after implantation. The injectable n-HA/PA66 composite has good biocompatibility and osteoconductive property. As an injectable material, with good maneuverability, it is useful for repairing irregular bone defects, especially in oral and maxillofacial surgery.
Alveolar Process ; drug effects ; physiology ; Animals ; Bone Regeneration ; drug effects ; physiology ; Bone Substitutes ; administration & dosage ; pharmacology ; Dogs ; Durapatite ; Injections ; Male ; Materials Testing ; Nylons ; Prosthesis Implantation ; methods ; X-Ray Diffraction

OBJECTIVETo study the effect of poly D,L-lactic acid (PDLLA) screws with PDLLA-rhBMP compound on bone regeneration in the screw holes and fracture ends of dog mandibles.

METHODSA self-control study was carried out in 4 dogs. PDLLA/rhBMP-2 compound screws were implanted to fix the mental fractures and PDLLA screws were used as control. The samples from mandibles were collected at 4, 8, 12, 16 weeks after implantation and observed by radiography and histology.

RESULTSAll dogs showed a greater degree of bone regeneration around PDLLA/rhBMP-2 screws than PDLLA ones and all fractures were fixed and healed well.

CONCLUSIONThe PDLLA-rhBMP screw has a better effect of inducing osteogenesis than PDLLA screw, and is able to exert a good fixation to fracture.

Animals ; Biocompatible Materials ; administration & dosage ; Bone Morphogenetic Protein 2 ; Bone Morphogenetic Proteins ; administration & dosage ; biosynthesis ; genetics ; Bone Screws ; Dogs ; Fracture Fixation, Internal ; methods ; Fracture Healing ; Lactic Acid ; administration & dosage ; Male ; Mandibular Fractures ; surgery ; Polyesters ; Polymers ; administration & dosage ; Recombinant Proteins ; administration & dosage ; biosynthesis ; genetics ; Transforming Growth Factor beta

Objective To investigate the trans-arterial delivery of p53 gene transfection efficiency and therapy effect on hepatic carcinoma in combination with transferrin mediated by liposome. Methods Twenty-five VX2 experimental rabbits were randomly divided into five groups, and the different doses of transferrin combined with p53-LipofectAMINE complex were delivered into the hepatic arteries of the VX2 hepatic carcinoma models. The tissue protein of the carcinoma was extracted after 48 h and the transfection efficiency and expression rate of p53 gene were analyzed by western blot and immune histochemical techniques, to inspect the expression proportion of p53 with different doses transferring. Another ten VX2 were divided into two groups, recombinant plasmid p53-LipofectAMINE complex and transferrin-p53-LipofectAMINE complex were delivered into the hepatic arteries in two groups respectively. The liver function, size of the tumor and survival time of the animals was compared between the two groups, and results were analyzed statistically. Results Semiquantitative analysis by Western Blot showed that the transfection and expression efficiency of p53 gene combined with transferrin were higher than those without it. By immune histochemieal techniques, the p53 gene's positive rate of highly expression with various doses of transferrin were found to be different, and there was remarkable difference between the groups with and without transferring. They were 58. 33%, 69. 44%, 80. 00%, 83.33%, 81.67% respectively, there was remarkable difference between the groups with and without transferring ( Totality: x2 = 42. 37, P < 0. 01 ). The p53 gene's positive rate of expression increased gradually as the doses of transferrin increasing from 0 up to 200 μg, but the differences of positive rate had no statistical significance as the doses of transferrin increasing from 200 up to 400 μg ( x2 section : 3 groups as former x2 = 4. 82, P < 0. 05,3 groups as latter x2 =0. 67 ,P <0. 05). There was no statistical difference in the liver function at points of time between VX2 rabbits with and without transferring. But the tumors' sizes had significant difference at various points of time. Conclusion Liposome-mediated p53 gene on treating hepatic carcinoma by trans-arterial gene delivery combined with transferrin is safe, and it can markedly enhance transfection efficiency and improve the therapy effect of p53 gene.

OBJECTIVEThe purpose of this study was to retrospect the prognosis of simultaneous repair of cleft lip and closure of cleft hard palate with vomer flaps in patients with unilateral complete cleft lip and palate.

METHODSA retrospective study was carried out in 47 patients with unilateral complete cleft lip and palate and, simultaneously received repair of cleft lip and closure of cleft hard palate with vomer flaps. The duration of operation, as well as the blood loss during the operation was recorded, and compared with those patients who only received cleft lip repair.

RESULTSAll the operations were successful, and the wound healed well. The procedure of simultaneous repair of cleft lip and closure of cleft hard palate with vomer flaps did not prolong the operating time, compared with simple cleft lip repair. No blood transfusion was needed due to closure of cleft hard palates with vomer flaps.

CONCLUSIONSimultaneous repairs of cleft lip and closure of cleft hard palate with vomer flaps are safe for patients with unilateral complete cleft lip and palate.

Abnormalities, Multiple ; surgery ; Cleft Lip ; surgery ; Cleft Palate ; surgery ; Female ; Humans ; Infant ; Male ; Maxillofacial Development ; Palate, Hard ; surgery ; Palate, Soft ; surgery ; Reconstructive Surgical Procedures ; methods ; Surgical Flaps

OBJECTIVEThe super-high-molecular-weight poly-DL-lactic acid (PDLLA), with the molecular weight of 900 kD, is a newly emerging biomaterial and potentially used in the therapy of bone fracture because of its excellent mechanical property. However the biocompatibility of this material has not been reported so far, therefore this experiment was designed to examine whether the super-high-molecular-weight PDLLA was harmful to creatures, when it was implanted in the body of animals for a long period.

METHODSThe material was prepared in small cuboids, with the size of 1.0 mm x 1.5 mm x 2.0 mm, and these blocks were implanted into the masseteric space of SD rats and, the activity of the SD-rats was monitored continuously. The animals were sacrificed in the 3rd, 6th, 9th, 12th months after the operation and, the specimens were taken out from the animals. The examination included anatomical, pathological and haematological methods. The data were analyzed with SPSS 8.0.

RESULTSThe wound healed well after the operation. Super-high-molecular-weight PDLLA degraded 6 months after the implantation. In the 3rd month after the operation, a thin fiber membrane around the materials was formed. In the 6th month, the membrane was much thinner than that in the 3rd month and completely disappeared in the 9th month. The pathological examination showed that slightly inflammatory reaction appeared in the tissue around these blocks in the 3rd month, but the inflammatory reactions were gradually remitted in the following 6th, 9th and 12th months. Further, the haematological examination did not show any abnormity during the 12-month observation period.

CONCLUSIONThe super-high-molecular-weight PDLLA can be degrade when it is implanted into the body of creatures, which proves its good biocompatibility.

Animals ; Biocompatible Materials ; chemistry ; metabolism ; Biodegradation, Environmental ; Bone Substitutes ; Implants, Experimental ; Lactic Acid ; chemistry ; metabolism ; Male ; Mandible ; metabolism ; surgery ; Molecular Weight ; Polyesters ; Polymers ; chemistry ; metabolism ; Rats ; Rats, Sprague-Dawley