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1.
Chinese Journal of Biotechnology ; (12): 942-960, 2023.
Article in Chinese | WPRIM | ID: wpr-970415

ABSTRACT

Collagen, which widely exists in skin, bone, muscle and other tissues, is a major structural protein in mammalian extracellular matrix. It participates in cell proliferation, differentiation, migration and signal transmission, plays an important role in tissue support and repair and exerts a protective effect. Collagen is widely used in tissue engineering, clinical medicine, food industry, packaging materials, cosmetics and medical beauty due to its good biological characteristics. This paper reviews the biological characteristics of collagen and its application in bioengineering research and development in recent years. Finally, we prospect the future application of collagen as a biomimetic material.


Subject(s)
Animals , Collagen/analysis , Tissue Engineering/methods , Extracellular Matrix/metabolism , Biomimetic Materials/chemistry , Bone and Bones , Tissue Scaffolds , Mammals/metabolism
2.
Journal of Korean Neurosurgical Society ; : 635-642, 2019.
Article in English | WPRIM | ID: wpr-765397

ABSTRACT

OBJECTIVE: The aim of this study was to investigate the biomechanical differences between human dura mater and dura mater substitutes to optimize biomimetic materials. METHODS: Four groups were investigated. Group I used cranial dura mater (n=10), group II used Gore-Tex® Expanded Cardiovascular Patch (W.L. Gore & Associates Inc., Flagstaff, AZ, USA) (n=6), group III used Durepair® (Medtronic Inc., Goleta, CA, USA) (n=6), and group IV used Tutopatch® (Tutogen Medical GmbH, Neunkirchen am Brand, Germany) (n=6). We used an axial compression machine to measure maximum tensile strength. RESULTS: The mean tensile strengths were 7.01±0.77 MPa for group I, 22.03±0.60 MPa for group II, 19.59±0.65 MPa for group III, and 3.51±0.63 MPa for group IV. The materials in groups II and III were stronger than those in group I. However, the materials in group IV were weaker than those in group I. CONCLUSION: An important dura mater graft property is biomechanical similarity to cranial human dura mater. This biomechanical study contributed to the future development of artificial dura mater substitutes with biomechanical properties similar to those of human dura mater.


Subject(s)
Humans , Biomimetic Materials , Collagen , Dura Mater , In Vitro Techniques , Mechanics , Pericardium , Polytetrafluoroethylene , Tensile Strength , Transplants
3.
Journal of Biomedical Engineering ; (6): 325-333, 2019.
Article in Chinese | WPRIM | ID: wpr-774203

ABSTRACT

In recent years, due to the dramatic increase in the number of surgical operations, there has been a clinically significant increase in the demand for medical adhesives capable of cohesion in a moist environment that can overcome blood or tissue fluids . As the understanding of the mechanisms and key elements of natural adhesion to aquatic organisms continues to develop, a variety of medical adhesives have been developed by mimicking adhesion procedures or utilizing key functional groups. This article will review the classification, adhesion mechanism, use, research progress and development prospects of biomedical adhesives inspired by aquatic organisms octopus and mussels.


Subject(s)
Animals , Adhesives , Biomimetic Materials , Bivalvia
4.
Journal of Korean Neurosurgical Society ; : 635-642, 2019.
Article in English | WPRIM | ID: wpr-788823

ABSTRACT

OBJECTIVE: The aim of this study was to investigate the biomechanical differences between human dura mater and dura mater substitutes to optimize biomimetic materials.METHODS: Four groups were investigated. Group I used cranial dura mater (n=10), group II used Gore-Tex® Expanded Cardiovascular Patch (W.L. Gore & Associates Inc., Flagstaff, AZ, USA) (n=6), group III used Durepair® (Medtronic Inc., Goleta, CA, USA) (n=6), and group IV used Tutopatch® (Tutogen Medical GmbH, Neunkirchen am Brand, Germany) (n=6). We used an axial compression machine to measure maximum tensile strength.RESULTS: The mean tensile strengths were 7.01±0.77 MPa for group I, 22.03±0.60 MPa for group II, 19.59±0.65 MPa for group III, and 3.51±0.63 MPa for group IV. The materials in groups II and III were stronger than those in group I. However, the materials in group IV were weaker than those in group I.CONCLUSION: An important dura mater graft property is biomechanical similarity to cranial human dura mater. This biomechanical study contributed to the future development of artificial dura mater substitutes with biomechanical properties similar to those of human dura mater.


Subject(s)
Humans , Biomimetic Materials , Collagen , Dura Mater , In Vitro Techniques , Mechanics , Pericardium , Polytetrafluoroethylene , Tensile Strength , Transplants
5.
Chinese Journal of Biotechnology ; (12): 2386-2400, 2019.
Article in Chinese | WPRIM | ID: wpr-781631

ABSTRACT

As an important auxiliary material, adhesive materials have many important applications in various fields including but not limited to industrial packaging, marine engineering, and biomedicine. Naturally occurring adhesives such as mussel foot proteins are usually biocompatible and biodegradable, but their limited sources and poor mechanical properties in physiological conditions have limited their widespread uses in biomedical field. Inspired by the underwater adhesion phenomenon of natural organisms, a series of biomimetic adhesive materials have been developed through chemical or bioengineering approaches. Notably, some of those synthetic adhesives have exhibited great promise for medical applications in terms of their biocompatibility, biodegradability, strong tissue adhesion and many other attractive functional properties. As natural adhesive materials possess distinctive "living" attributes such as environmental responsiveness, self-regeneration and autonomous repairs, the development of various biologically inspired and biomimetic adhesive materials using natural adhesives as blueprints will thus be of keen and continuous interest in the future. The emerging field of synthetic biology will likely provide new opportunities to design living glues that recapitulate the dynamic features of those naturally occurring adhesives.


Subject(s)
Animals , Adhesives , Biocompatible Materials , Biomimetic Materials , Chemistry , Biomimetics , Bivalvia
6.
Frontiers of Medicine ; (4): 667-677, 2018.
Article in English | WPRIM | ID: wpr-772715

ABSTRACT

Platelets have long been known to play critical roles in hemostasis by clumping and clotting blood vessel injuries. Recent experimental evidence strongly indicates that platelets can also interact with tumor cells by direct binding or secreting cytokines. For example, platelets have been shown to protect circulating cancer cells in blood circulation and to promote tumor metastasis. In-depth understanding of the role of platelets in cancer progression and metastasis provides promising approaches for platelet biomimetic drug delivery systems and functional platelet-targeting strategies for effective cancer treatment. This review highlights recent progresses in platelet membrane-based drug delivery and unique strategies that target tumor-associated platelets for cancer therapy. The paper also discusses future development opportunities and challenges encountered for clinical translation.


Subject(s)
Animals , Humans , Antineoplastic Agents , Chemistry , Pharmacology , Biomimetic Materials , Chemistry , Blood Platelets , Cell Biology , Drug Carriers , Chemistry , Models, Animal , Nanomedicine , Methods , Nanostructures , Chemistry , Neoplasms , Drug Therapy
7.
Univ. odontol ; 37(79)2018. ilus, tab
Article in Spanish | LILACS, COLNAL | ID: biblio-995675

ABSTRACT

Antecedentes: Los agentes blanqueadores oxidantes tales como los peróxidos generan daños irreversibles en el esmalte dental y afectan químicamente el componente orgánico e inorgánico del esmalte. Se reportan en la literatura sustancias alternativas que pueden mejorar el color del esmalte, sin causarle daño. Objetivo: Identificar las sustancias blanqueadoras tipo remineralizante reportadas en la literatura y su efecto en el color del esmalte dental. Métodos: Se consultaron las bases de datos PubMed, ScienceDirect, Embase, Scielo, Lilacs y Scopus, las palabras clave empleadas para la búsqueda fueron dental enamel, tooth bleaching, bleaching, calcium phosphate, hidroxyapatite, apatite, biomimetic, biomimetics, conectadas por el operador booleano AND y OR de diferentes maneras. Los criterios de elegibilidad de los artículos que harían parte de la revisión fueron que no incluyeran peróxidos de hidrógeno y carbamida con adición fluoruros y fosfatos de calcio y adicionalmente que emplearan un método de medición de color. Resultados: El resultado de la búsqueda arrojó 7 artículos, las sustancias encontradas de tipo remineralizante fueron hidroxiapatita sintética, fosfatos de calcio y el hexametafosfato de sodio. Según los criterios de evaluación definidos solo 4 de ellos tuvieron un nivel de evidencia alto, uno nivel medio y dos bajos. Todos los estudios reportan con los tratamientos probados, la capacidad de generar cambios en el color del esmalte dental. Conclusión: Las sustancias blanqueadoras remineralizantes encontradas, tienen la capacidad de producir cambios en el color del esmalte dental, lo cual se evidencia con modificación en las diferentes escalas de medición empleadas.


Background: Oxidizing bleaching agents such as peroxides generate irreversible damage to dental enamel and chemically affect the organic and inorganic component of the enamel. Alternative substances that can improve the color of the enamel without damaging it are reported in the literature. Purpose: To identify the remineralizing bleaching substances reported in the literature and their effect on the color of the dental enamel. Methods: The databases PubMed, ScienceDirect, Embase, SciELO, Lilacs and Scopus were consulted, the keywords used for the search were dental enamel, tooth bleaching, bleaching, calcium phosphate, hydroxyapatite, apatite, biomimetic, biomimetics, connected by the Boolean operator AND and OR in different ways. The eligibility criteria of the articles that would be part of the review were not to include hydrogen peroxide and carbamide peroxides with addition of fluorides and calcium phosphates and additionally using a color measurement method. Results: The result of the search yielded 7 articles, the substances found of remineralizing type were synthetic hydroxyapatite, calcium phosphates and sodium hexametaphosphate. According to the evaluation criteria defined, only 4 of them had a high level of evidence, one medium level and two low. All studies report with proven treatments the ability to generate changes in tooth enamel color. Conclusions: The remineralizing whitening substances found have the ability to produce changes in the color of the dental enamel, which is evidenced with modification in the different measurement scales used.


Subject(s)
Humans , Tooth Bleaching/methods , Biomimetic Materials/analysis , Dental Materials/analysis , Dental Enamel , Esthetics, Dental
8.
IBJ-Iranian Biomedical Journal. 2017; 21 (4): 218-227
in English | IMEMR | ID: emr-189231

ABSTRACT

Background: Islet transplantation could be an ideal alternative treatment to insulin therapy for type 1 diabetes Mellitus [T1DM]. This clinical and experimental field requires a model that covers problems such as requiring a large number of functional and viable islets, the optimal transplantation site, and the prevention of islet dispersion. Hence, the methods of choice for isolation of functional islets and transplantation are crucial


Methods: The present study has introduced an experimental model that overcomes some critical issues in islet transplantation, including in situ pancreas perfusion by digestive enzymes through common bile duct. In comparison with conventional methods, we inflated the pancreas in Petri dishes with only 1 ml collagenase type XI solution, which was followed by hand-picking isolation or Ficoll gradient separation to purify the islets. Then we used a hydrogel composite in which the islets were embedded and transplanted into the peritoneal cavity of the streptozotocin-induced diabetic C57BL/6 mice


Results: As compared to the yield of the classical methods, in our modified technique, the mean yield of isolation was about 130-200 viable islets/mouse pancreas. In vitro glucosemediated insulin secretion assay indicated an appropriate response in isolated islets. In addition, data from in vivo experiments revealed that the allograft remarkably maintained blood glucose levels under 400 mg/dl and hydrogel composite prevents the passage of immune cells


Conclusion: In the model presented here, the rapid islet isolation technique and the application of biomimetic hydrogel wrapping of islets could facilitate islet transplantation procedures


Subject(s)
Animals, Laboratory , Biomimetic Materials , Biomimetics , Hydrogels , Diabetes Mellitus, Type 1 , Mice , Diabetes Mellitus, Experimental , Streptozocin
9.
Restorative Dentistry & Endodontics ; : 143-147, 2016.
Article in English | WPRIM | ID: wpr-205722

ABSTRACT

The reconstruction of structurally compromised posterior teeth is a rather challenging procedure. The tendency of endodontically treated teeth (ETT) to fracture is considerably higher than vital teeth. Although posts and core build-ups followed by conventional crowns have been generally employed for the purpose of reconstruction, this procedure entails sacrificing a considerable amount of residual sound enamel and dentin. This has drawn the attention of researchers to fibre reinforcement. Fibre-reinforced composite (FRC), designed to replace dentin, enables the biomimetic restoration of teeth. Besides improving the strength of the restoration, the incorporation of glass fibres into composite resins leads to favorable fracture patterns because the fibre layer acts as a stress breaker and stops crack propagation. The following case report presents a technique for reinforcing a badly broken-down ETT with biomimetic materials and FRC. The proper utilization of FRC in structurally compromised teeth can be considered to be an economical and practical measure that may obviate the use of extensive prosthetic treatment.


Subject(s)
Biomimetic Materials , Biomimetics , Composite Resins , Crowns , Dental Enamel , Dentin , Glass , Molar , Tooth
10.
Chinese Journal of Stomatology ; (12): 109-113, 2016.
Article in Chinese | WPRIM | ID: wpr-259434

ABSTRACT

<p><b>OBJECTIVE</b>To explore biomimetic mineralization of polyelectrolyte multilayer films (PEM) of gene-loaded lipopolysaccharide-amine nanopolymersomes/hyaluronic acid self assembled on titanium surface.</p><p><b>METHODS</b>Via lay-by-layer self assembly technology, PEM were constructed on titanium or quartz surface using bone morphogenetic protein-2(BMP-2) plasmid-loaded lipopolysaccharide-amine nanopolymersomes(pLNP) as a polycation, and hyaluronic acid(HA) as a polyanion. The constructed PEM were defined as substrate-pLNP-(HA-pLNP)n, where a successive deposition of HA and pLNP on substrate surface was defined as one assembly cycle, and n was the cycle number. Biomimetic mineralization on surfaces of Ti-pLNP-(HA-pLNP)4(Group A, with outermost layer of pLNP), Ti-pLNP-(HA-pLNP)4.5(Group B, with outermost layer of HA), blank control(polished titanium, Ti) and alkaline-heat treated titanium(Ti-OH) were investigated. The biomimetic mineralization was analyzed by observing the topography under field-emisssion electron microscopy(FE-SEM), characterizing the surface chemical structure and components via X-ray diffractometer(XRD) and X-ray energy disperse spectroscopy(EDS).</p><p><b>RESULTS</b>For experiment groups, XRD analysis showed that the diffraction peak of hydroxyapatite appeared, and its intensity was higher than that for Ti group. FE-SEM images showed that its surface was homogeneously covered by discrete agglomerate of big particles. EDS spectra showed that the percentage of Ca and P were 77.24% and 64.23%, and these were much higher than those in Ti group.</p><p><b>CONCLUSIONS</b>The surface of Ti-pLNP-(HA-pLNP)n is favorable for in vitro biomimetic mineralization.</p>


Subject(s)
Amines , Chemistry , Biomimetic Materials , Chemistry , Bone Morphogenetic Protein 2 , Durapatite , Chemistry , Hyaluronic Acid , Chemistry , Lipopolysaccharides , Nanocomposites , Chemistry , Plasmids , Surface Properties , Titanium , Chemistry
11.
Chinese Journal of Stomatology ; (12): 540-544, 2014.
Article in Chinese | WPRIM | ID: wpr-260782

ABSTRACT

<p><b>OBJECTIVE</b>To study the incorporation rate and release behavior of bovine serum albumin (BSA) incorporated into the calcium phosphate coating by biomimetic deposition, as well as the physical and chemical properties of the hybrid coating, and to provide experimental basis for the fabrication of growth factor/biomimetic calcium phosphate coating and exploration for the loading/release behavior of growth factors.</p><p><b>METHODS</b>Pure titanium specimens were immersed into saturated calcium phosphate solutions(SCP) containing no BSA (controlled group) and 3 different concentrations of BSA (experimental groups) : 1, 10 and 100 mg/L. Biomimetic calcium phosphate coating was formed on titanium surface and BSA was incorporated into the coating through co-deposition. The topography of the specimen was observed using scanning electron microscopy (SEM). Chemical structure and phase composition of coatings were detected by Fourier infrared spectroscopy (FTIR) analysis and X-ray diffraction (XRD) respectively. BSA incorporation rate and release profile were determined by bicinchoninic acid protein assay kit.</p><p><b>RESULTS</b>The biomimetic calcium phosphate coating was mainly composed of hydroxyapatite and octacalcium phosphate. BSA was successfully incorporated into the calcium phosphate coatings in all the 3 experimental groups. With the increase of BSA concentration, plate-like units of the coatings were turned into small grid structure. BSA incorporation rates of the three experimental groups were (72.4 ± 2.4)%, (62.3 ± 0.9)% and (42.2 ± 1.7)% respectively. The in vitro release test showed that all three BSA release profiles could be divided into two significant different stages: early burst release stage and later sustained release stage. The amount of BSA release of the 3 experimental groups in 24 h and 30 d were (1.57 ± 0.09), (8.82 ± 0.93), (140.24 ± 3.12) µg, and (2.39 ± 0.29), (14.39 ± 0.70), (151.06 ± 2.00) µg respectively.</p><p><b>CONCLUSIONS</b>Biomimetic calcium phosphate coating can be used as an effective carrier for protein. BSA concentration has an impact on the incorporation rate and release speed of BSA from the calcium phosphate coating. Favorable BSA incorporation rate and release behavior can be obtained at BSA concentration of 10 mg/L.</p>


Subject(s)
Biomimetic Materials , Calcium Phosphates , Chemistry , Durapatite , In Vitro Techniques , Microscopy, Electron, Scanning , Serum Albumin, Bovine , Metabolism , Spectrophotometry, Infrared , Surface Properties , Titanium , X-Ray Diffraction
12.
Journal of Central South University(Medical Sciences) ; (12): 949-958, 2014.
Article in Chinese | WPRIM | ID: wpr-815510

ABSTRACT

OBJECTIVE@#To prepare nHA/gelatin porous scaffold and to evaluate its physical and chemical properties and biocompatibility.@*METHODS@#We used nano-powders of HA and gelatin to prepare 3D porous composite scaffold by freeze-drying technique, and used scanning electron microscope, fourier transform infrared spectroscopy and universal testing machine to characterize the composite material. Osteoblasts were primarily cultured, and the third-passage osteoblasts were co-cultured with the composite material. The cell adhesion and morphology were examined under scanning electron microscope. The cell viability analysis was performed by MTT assay, and the alkaline phosphatase activity was measured with alkaline phosphatase kit.@*RESULTS@#Scanning electron microscope showed that the scaffold possessed a 3-dimensional interconnected homogenous porous structure with pore sizes ranging from 150 to 400 μm. Fourier transform infrared spectroscopy showed that the composite material had a strong chemical bond between the inorganic phase and organic phase. The scaffold presented the compressive strength of (3.28 ± 0.51) MPa and porosities of (80.6 ± 4.1)%. Composite materials showed features of had good biocompatibility. Mouse osteoblasts were well adhered and spread on the materials. The grade of the cell toxicity ranged from I to II. On the 5th and 7th day the proliferative rate of osteoblasts on scaffolds in the composite materials was significantly higher than that in the control group. The activity of alkaline phosphatase was obviously higher than that in the control group on Day 1 and 3.@*CONCLUSION@#Nano-hydroxyapatite and gelatin in certain proportions and under certain conditions can be prepared into a composite biomimetic porous scaffolds with high porosity and three-dimensional structure using freeze-drying method. The scaffold shows good biocompatibility with mouse osteoblasts and may be a novel scaffolds for bone tissue engineering.


Subject(s)
Animals , Mice , Biocompatible Materials , Biomimetic Materials , Bone and Bones , Cell Adhesion , Coculture Techniques , Durapatite , Gelatin , Nanostructures , Osteoblasts , Cell Biology , Porosity , Spectroscopy, Fourier Transform Infrared , Tissue Engineering , Tissue Scaffolds
13.
Actas odontol ; 10(1): 16-27, jul. 2013.
Article in Spanish | LILACS, BNUY | ID: lil-727890

ABSTRACT

La odontología restauradora actual debe estar sustentada en una filosofía preventiva, conservadora y de máxima preservación de las estructuras dentarias naturales.Con restauraciones que pueden ser consideradas como “fusionadas” a las estructuras dentarias, lo que implica la existencia de una relacióníntima y sub-estructural entre restauración, cemento adhesivo y tejido dentario, no mucho tiempo atrás, se propuso un “continuum restaurador” para el sector anterior de boca.Este trabajo propone y desarrolla ahora, un “continuum restaurador” para el sector posterior, en el entendido que con una correcta planificación que considere detenidamente la biomecánica de la oclusión para cada caso, dichas restauraciones adheridas tendrán una performance satisfactoria a mediano y largo plazo.


Nowadays, restorative dentistry should be based in a preventive and conservative philosophy of maximum preservation of the naturaldental structures.A “restorative continuum” has been proposed for the anterior sector of the mouth, not long ago. It involves restorations that are consideredas “fusioned” to the dental structures, existing an intimate and sub-estructural relation between restoration, adhesive cement and dental tissues.This paper suggests and develops a “restorative continuum” for the posterior sector of the mouth, based on a proper planification that considers the biomechanics of the occlusion in each case, where these bonded restorations will have middle and long term satisfactory performance.


Subject(s)
Humans , Inlays , Biomimetic Materials/therapeutic use , Dental Restoration, Permanent/methods , Dental Veneers , Denture, Partial, Fixed, Resin-Bonded , Esthetics, Dental
14.
International Journal of Oral Science ; (4): 103-110, 2013.
Article in English | WPRIM | ID: wpr-358185

ABSTRACT

Tooth bleaching agents may weaken the tooth structure. Therefore, it is important to minimize any risks of tooth hard tissue damage caused by bleaching agents. The aim of this study was to evaluate the effects of applying 45S5 bioglass (BG) before, after, and during 35% hydrogen peroxide (HP) bleaching on whitening efficacy, physicochemical properties and microstructures of bovine enamel. Seventy-two bovine enamel blocks were prepared and randomly divided into six groups: distilled deionized water (DDW), BG, HP, BG before HP, BG after HP and BG during HP. Colorimetric and microhardness tests were performed before and after the treatment procedure. Representative specimens from each group were selected for morphology investigation after the final tests. A significant color change was observed in group HP, BG before HP, BG after HP and BG during HP. The microhardness loss was in the following order: group HP>BG before HP, BG after HP>BG during HP>DDW, BG. The most obvious morphological alteration of was observed on enamel surfaces in group HP, and a slight morphological alteration was also detected in group BG before HP and BG after HP. Our findings suggest that the combination use of BG and HP could not impede the tooth whitening efficacy. Using BG during HP brought better protective effect than pre/post-bleaching use of BG, as it could more effectively reduce the mineral loss as well as retain the surface integrity of enamel. BG may serve as a promising biomimetic adjunct for bleaching therapy to prevent/restore the enamel damage induced by bleaching agents.


Subject(s)
Animals , Cattle , Biomimetic Materials , Therapeutic Uses , Ceramics , Chemistry , Chemical Phenomena , Color , Colorimetry , Dental Enamel , Electron Probe Microanalysis , Glass , Chemistry , Hardness , Hydrogen Peroxide , Pharmacology , Hydrogen-Ion Concentration , Microscopy, Electron, Scanning , Protective Agents , Therapeutic Uses , Random Allocation , Solubility , Spectroscopy, Fourier Transform Infrared , Time Factors , Tooth Bleaching , Methods , Tooth Bleaching Agents , Pharmacology , Water , Chemistry , X-Ray Diffraction
15.
China Journal of Chinese Materia Medica ; (24): 666-669, 2013.
Article in Chinese | WPRIM | ID: wpr-350710

ABSTRACT

<p><b>OBJECTIVE</b>To find out whether and how the newly invented technique-bionic glue affects the main pest of wolf berry-Paratrioza sinica and its natural enemies Tamarixia lyciumi and Chrysopa septempunctata.</p><p><b>METHOD</b>Spraying bionic glue in field when wolf berry just geminated, investigated the adults and nymphs of P. sinica and it's natural enemies: adults of T. lyciumi and eggs of C. septempunctata.</p><p><b>RESULT AND CONCLUSION</b>Bionic glue can significantly reduce the population number of P. sinica, but with little impacts on its natural enemies of T. lyciumi and C. septempunctata, and more experiments are need for further research.</p>


Subject(s)
Animals , Adhesives , Pharmacology , Bees , Biomimetic Materials , Pharmacology , Hemiptera , Ovum , Population Dynamics , Predatory Behavior
16.
China Journal of Chinese Materia Medica ; (24): 4292-4297, 2013.
Article in Chinese | WPRIM | ID: wpr-287595

ABSTRACT

<p><b>OBJECTIVE</b>To prepare colon target pellets of Pulsatilla total saponins.</p><p><b>METHOD</b>Pulsatilla total saponins-hydroxypropyl-beta-cyclodextrin inclusion was prepared by the water solution-mixing method. Then plain pills of inclusion were prepared by the granulation-spheronization method, and coated by Glatt fluid bed.</p><p><b>RESULT</b>The dissolution of plain pills of Pulsatilla total saponins at 2 h was 16.0%, while that of plain pills of inclusion at 0.5 h was 91.9%. With Eudragit S100 as the coating material, TEC as the plasticizer and talcum power as the anti-adherent, when the coating weight was 12%, the coating efficiency was high, with almost no bonding and drug release of coated pellets in artificial gastric juice for 2 h. The accumulated drug release in artificial intestinal fluid for 4 h was less than 15%, and that in artificial colon fluid for 4 h was more than 90%.</p><p><b>CONCLUSION</b>Coated pellets of Pulsatilla total saponins-hydroxypropyl-beta-cyclodextrin inclusion showed a good colon targeted drug release in vitro, thus could be further developed to be oral colon targeted preparations.</p>


Subject(s)
Humans , 2-Hydroxypropyl-beta-cyclodextrin , Absorption , Biomimetic Materials , Metabolism , Colon , Metabolism , Drug Compounding , Methods , Drug Implants , Gastric Juice , Metabolism , Pulsatilla , Chemistry , Saponins , Chemistry , Metabolism , Surface Properties , beta-Cyclodextrins , Chemistry
17.
Journal of Southern Medical University ; (12): 1554-1556, 2013.
Article in Chinese | WPRIM | ID: wpr-232752

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the apatite forming ability of pure titanium implant after micro-arc oxidation treatment in simulated body fluid (SBF) and obtain implants with calcium phosphate (Ca-P) layers.</p><p><b>METHODS</b>The implants were immersed in (SBF) after micro-arc oxidation treatment for different time lengths, and their apatite forming ability and the morphology and constituents of the Ca-P layers formed on the sample surface were analyzed using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and energy dispersive electron probe.</p><p><b>RESULTS</b>After immersion in SBF, large quantities of Ca-P layers were induced on the surface of the samples. The Ca-P layers were composed of octacalcium phosphate and carbonated hydroxyapatite, and the crystals showed a plate-like morphology with an oriented growth.</p><p><b>CONCLUSION</b>The implants with micro-arc oxidation treatment show good apatite forming ability on the surface with rich calcium and phosphorus elements. The formed layers are composed of bone-like apatite including octacalcium phosphate and carbonated hydroxyapatite.</p>


Subject(s)
Apatites , Chemistry , Biomimetic Materials , Chemistry , Body Fluids , Chemistry , Calcium Phosphates , Chemistry , Coated Materials, Biocompatible , Chemistry , Durapatite , Chemistry , Oxidation-Reduction , Prostheses and Implants , Random Allocation , Surface Properties , Titanium , Chemistry
18.
International Journal of Oral Science ; (4): 69-77, 2012.
Article in English | WPRIM | ID: wpr-358222

ABSTRACT

Cementum is the outer-, mineralized-tissue covering the tooth root and an essential part of the system of periodontal tissue that anchors the tooth to the bone. Periodontal disease results from the destructive behavior of the host elicited by an infectious biofilm adhering to the tooth root and left untreated, may lead to tooth loss. We describe a novel protocol for identifying peptide sequences from native proteins with the potential to repair damaged dental tissues by controlling hydroxyapatite biomineralization. Using amelogenin as a case study and a bioinformatics scoring matrix, we identified regions within amelogenin that are shared with a set of hydroxyapatite-binding peptides (HABPs) previously selected by phage display. One 22-amino acid long peptide regions referred to as amelogenin-derived peptide 5 (ADP5) was shown to facilitate cell-free formation of a cementum-like hydroxyapatite mineral layer on demineralized human root dentin that, in turn, supported attachment of periodontal ligament cells in vitro. Our findings have several implications in peptide-assisted mineral formation that mimic biomineralization. By further elaborating the mechanism for protein control over the biomineral formed, we afford new insights into the evolution of protein-mineral interactions. By exploiting small peptide domains of native proteins, our understanding of structure-function relationships of biomineralizing proteins can be extended and these peptides can be utilized to engineer mineral formation. Finally, the cementomimetic layer formed by ADP5 has the potential clinical application to repair diseased root surfaces so as to promote the regeneration of periodontal tissues and thereby reduce the morbidity associated with tooth loss.


Subject(s)
Humans , Amelogenin , Chemistry , Physiology , Biomimetic Materials , Chemistry , Calcium-Binding Proteins , Carrier Proteins , Physiology , Cementogenesis , Physiology , Dental Cementum , Chemistry , Peptide Fragments , Peptide Mapping , Methods , Peptides , Physiology , Protein Engineering , Methods , Sequence Homology, Amino Acid , Tissue Engineering , Methods , Tooth Calcification , Physiology
19.
Journal of Biomedical Engineering ; (6): 474-478, 2012.
Article in Chinese | WPRIM | ID: wpr-271749

ABSTRACT

The aim of this study is to investigate a new method for preparing a biomimetic bone material-surface modified sintered bovine cancellous bone, and to improve its bioactivity as a tissue engineering bone. The prepared sintered bovine cancellous bones with the same size were randomly divided into two groups, immersing in 1 and 1. 5 times simulated body fluid (SBF), respectively. The three time periods of soak time were 7, 14, and 21 days. After sintered bone was dried, the surface morphology of sintered bone and surface mineralization composition were observed under scanning electron microscopy (SEM). By comparing the effect of surface modification of sintered bone materials, we chose the most ideal material and studied its pore size, the rate of the porosity, the compress and bend intensity. And then the material and the sintered bone material without surface modification were compared. The study indicated that sintered bone material immersed in SBF (1.5 times) for 14 days showed the best effect of surface modification, retaining the original physico-chemical properties of sintered bone.


Subject(s)
Animals , Cattle , Biocompatible Materials , Biomimetic Materials , Bone Substitutes , Bone and Bones , Chemistry , Calcification, Physiologic , Physiology , Chemical Phenomena , Hydroxyapatites , Chemistry , Porosity , Surface Properties , Tissue Engineering , Methods
20.
Rev. dental press periodontia implantol ; 5(3): 42-49, jul.-set.2011. tab
Article in Portuguese | LILACS, BBO | ID: lil-616329

ABSTRACT

O sucesso dos implantes está, frequentemente, associado ao processo de osseointegração. Isso leva a uma busca por tratamentos de superfície para que o titânio se torne cada vez mais bioativo e induza a neoformação óssea. O conceito da superfície biomimética surge com o intuito de gerar uma superfície que module positivamente a osseointegração, de modo que o implante apresente capacidade de osteoindução por meio do reconhecimento biomolecular da superfície. A hidroxiapatita e os fosfatos de cálcio foram os primeiro agentes propostos para o biomimetismo da superfície com o tecido ósseo; no entanto, hoje é proposta a utilização de proteínas da matriz extracelular óssea e fatores de crescimento para mimetizar a fisiologia do tecido e aumentar ainda mais a previsibilidade dos implantes. Quando os resultados das pesquisas puderem ser traduzidos em projetos industriais, novas superfícies podem surgir no mercado, garantindo maior segurança para a instalação de implantes em sítios ósseos desfavoráveis e o carregamento oclusal precoce.


Dental implants success is often associated with the osseointegration process. To induce the bone formation, there is a search for surface treatments to create a more bioactive titanium. The concept of biomimetic surface arises in order to generate a surface that positively modulates the implant osseointegration, presenting osteoinductive capacity through the biomolecular recognition of the surface. Hydroxyapatite and calcium phosphates were the first agents proposed for surface coating to mimic the bone tissue; however. the use of bone extracellular matrix proteins and growth factors have been proposed to mimic the physiology of the tissue and further increase its predictability. When the research results become translated into industrial projects, new surfaces may emerge in the market providing greater security for implants installation in unfavorable bone sites and early occlusal loading.


Subject(s)
Extracellular Matrix Proteins , Intercellular Signaling Peptides and Proteins , Dental Implants , Osseointegration , Biomimetic Materials , Surface Properties , Titanium
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