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Int J Mol Sci ; 22(14)2021 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-34298988


This study evaluated the biocompatibility and biological performance of novel additive-manufactured bioabsorbable iron-based porous suture anchors (iron_SAs). Two types of bioabsorbable iron_SAs, with double- and triple-helical structures (iron_SA_2_helix and iron_SA_3_helix, respectively), were compared with the synthetic polymer-based bioabsorbable suture anchor (polymer_SAs). An in vitro mechanical test, MTT assay, and scanning electron microscope (SEM) analysis were performed. An in vivo animal study was also performed. The three types of suture anchors were randomly implanted in the outer cortex of the lateral femoral condyle. The ultimate in vitro pullout strength of the iron_SA_3_helix group was significantly higher than the iron_SA_2_helix and polymer_SA groups. The MTT assay findings demonstrated no significant cytotoxicity, and the SEM analysis showed cells attachment on implant surface. The ultimate failure load of the iron_SA_3_helix group was significantly higher than that of the polymer_SA group. The micro-CT analysis indicated the iron_SA_3_helix group showed a higher bone volume fraction (BV/TV) after surgery. Moreover, both iron SAs underwent degradation with time. Iron_SAs with triple-helical threads and a porous structure demonstrated better mechanical strength and high biocompatibility after short-term implantation. The combined advantages of the mechanical superiority of the iron metal and the possibility of absorption after implantation make the iron_SA a suitable candidate for further development.

Implantes Absorvíveis , Materiais Biocompatíveis , Âncoras de Sutura , Alanina Transaminase/sangue , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/toxicidade , Fenômenos Biomecânicos , Nitrogênio da Ureia Sanguínea , Fosfatos de Cálcio/química , Fosfatos de Cálcio/toxicidade , Sulfato de Cálcio/administração & dosagem , Sulfato de Cálcio/química , Sulfato de Cálcio/toxicidade , Creatinina/sangue , Desenho de Equipamento , Fêmur/diagnóstico por imagem , Fêmur/ultraestrutura , Ferro , Lasers , Teste de Materiais , Microscopia Eletrônica de Varredura , Estrutura Molecular , Osseointegração , Polímeros/química , Polímeros/toxicidade , Porosidade , Coelhos , Distribuição Aleatória , Resistência à Tração , Vísceras , Microtomografia por Raio-X
Sci Rep ; 11(1): 9610, 2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-33953260


We demonstrated the design of pre-additive manufacturing microalloying elements in tuning the microstructure of iron (Fe)-based alloys for their tunable mechanical properties. We tailored the microalloying stoichiometry of the feedstock to control the grain sizes of the metallic alloy systems. Two specific microalloying stoichiometries were reported, namely biodegradable iron powder with 99.5% purity (BDFe) and that with 98.5% (BDFe-Mo). Compared with the BDFe, the BDFe-Mo powder was found to have lower coefficient of thermal expansion (CTE) value and better oxidation resistance during consecutive heating and cooling cycles. The selective laser melting (SLM)-built BDFe-Mo exhibited high ultimate tensile strength (UTS) of 1200 MPa and fair elongation of 13.5%, while the SLM-built BDFe alloy revealed a much lower UTS of 495 MPa and a relatively better elongation of 17.5%, indicating the strength enhancement compared with the other biodegradable systems. Such an enhanced mechanical behavior in the BDFe-Mo was assigned to the dominant mechanism of ferrite grain refinement coupled with precipitate strengthening. Our findings suggest the tunability of outstanding strength-ductility combination by tailoring the pre-additive manufacturing microalloying elements with their proper concentrations.

Int J Mol Sci ; 21(10)2020 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-32455543


The interference screw fixation method is used to secure a graft in the tibial tunnel during anterior cruciate ligament reconstruction surgery. However, several complications have been reported, such as biodegradable screw breakage, inflammatory or foreign body reaction, tunnel enlargement, and delayed graft healing. Using additive manufacturing (AM) technology, we developed a titanium alloy (Ti6Al4V) interference screw with chemically calcium phosphate surface modification technology to improve bone integration in the tibial tunnel. After chemical and heat treatment, the titanium screw formed a dense apatite layer on the metal surface in simulated body fluid. Twenty-seven New Zealand white rabbits were randomly divided into control and additive manufactured (AMD) screw groups. The long digital extensor tendon was detached and translated into a tibial plateau tunnel (diameter: 2.0 mm) and transfixed with an interference screw while the paw was in dorsiflexion. Biomechanical analyses, histological analyses, and an imaging study were performed at 1, 3, and 6 months. The biomechanical test showed that the ultimate pull-out load failure was significantly higher in the AMD screw group in all tested periods. Micro-computed tomography analyses revealed early woven bone formation in the AMD screw group at 1 and 3 months. In conclusion, AMD screws with bioactive surface modification improved bone ingrowth and enhanced biomechanical performance in a rabbit model.

Parafusos Ósseos/normas , Osseointegração , Impressão Tridimensional , Tendões/cirurgia , Tíbia/cirurgia , Ligas/química , Animais , Parafusos Ósseos/efeitos adversos , Interface Osso-Implante/cirurgia , Fosfatos de Cálcio/química , Porosidade , Coelhos
J Orthop Res ; 36(10): 2633-2640, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29727018


The interference screw is a widely used fixation device in the anterior cruciate ligament (ACL) reconstruction surgeries. Despite the generally satisfactory results, problems of using interference screws were reported. By using additive manufacturing (AM) technology, we developed an innovative titanium alloy (Ti6 Al4 V) interference screw with rough surface and inter-connected porous structure designs to improve the bone-tendon fixation. An innovative Ti6 Al4 V interference screws were manufactured by AM technology. In vitro mechanical tests were performed to validate its mechanical properties. Twenty-seven New Zealand white rabbits were randomly divided into control and AM screw groups for biomechanical analyses and histological analysis at 4, 8, and 12 weeks postoperatively; while micro-CT analysis was performed at 12 weeks postoperatively. The biomechanical tests showed that the ultimate failure load in the AM interference screw group was significantly higher than that in the control group at all tested periods. These results were also compatible with the findings of micro-CT and histological analyses. In micro-CT analysis, the bone-screw gap was larger in the control group; while for the additive manufactured screw, the screw and bone growth was in close contact. In histological study, the bone-screw gaps were wider in the control group and were almost invisible in the AM screw group. The innovative AM interference screws with surface roughness and inter-connected porous architectures demonstrated better bone-tendon-implant integration, and resulted in stronger biomechanical characteristics when compared to traditional screws. These advantages can be transferred to future interference screw designs to improve their clinical performance. The AM interference screw could improve graft fixation and eventually result in better biomechanical performance of the bone-tendon-screw construct. The innovative AM interference screws can be transferred to future interference screw designs to improve the performance of implants. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:2633-2640, 2018.

Reconstrução do Ligamento Cruzado Anterior/instrumentação , Parafusos Ósseos , Tendões/cirurgia , Animais , Fenômenos Biomecânicos , Porosidade , Coelhos , Distribuição Aleatória , Titânio , Microtomografia por Raio-X
J Chromatogr B Analyt Technol Biomed Life Sci ; 853(1-2): 183-9, 2007 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-17400527


This study presents a validated liquid chromatography technique coupled with tandem mass spectrometry (LC-MS/MS) to measure curcumin in rat plasma and provide curcuminoids analysis from the extract of Curcumin longa L. This method was applied to investigate the pharmacokinetics of curcumin in a freely moving rat. The analytes were separated by a reversed phase C18 column (150x4.6 mm I.D., particle size 5 microm) and eluted with acetonitrile-1mM HCOOH mobile phase (70:30, v/v) with a flow rate of 0.8 ml/min in rat plasma and herbal extracts. Multiple reaction monitoring (MRM) was used to monitor the transition of the deprotonated molecule m/z of 367 [M-H]- to the product ion 217 for curcumin, a m/z of 337-217 for demethoxycurcumin and a m/z of 265-224 for honokiol (internal standard) analysis. The limit of detection (LOD) and quantification (LOQ) of curcumin in the rat plasma were 1 and 5 ng/ml, respectively. The method was linear in the range of 5-1000 ng/ml with a coefficient of correlation greater than 0.996 in the rat plasma. After curcumin (500 mg/kg, p.o.) administration, the maximum concentration (Cmax) and the time to reach maximum concentration (Tmax) were 0.06+/-0.01 microg/ml and 41.7+/-5.4 min, respectively. The elimination half-life (t1/2,beta) were 28.1+/-5.6 and 44.5+/-7.5 min for curcumin (500 mg/kg, p.o.) and curcumin (10 mg/kg, i.v.), respectively. The oral bioavailability was about 1%.

Cromatografia Líquida/métodos , Curcuma/química , Curcumina/análise , Espectrometria de Massas em Tandem/métodos , Administração Oral , Animais , Disponibilidade Biológica , Curcumina/administração & dosagem , Curcumina/farmacocinética , Estrutura Molecular , Extratos Vegetais/administração & dosagem , Extratos Vegetais/análise , Extratos Vegetais/farmacocinética , Ratos , Reprodutibilidade dos Testes
J Chromatogr A ; 1073(1-2): 285-9, 2005 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-15909531


Daphnoretin (7-hydroxyl-6-methoxy-3,7'-dicoumaryl ether), isolated from Wikstronemia indica C.A. Mey. (Thymelaceae), has been reported to induce rabbit platelet aggregation through protein kinase C activation and anticancer activity. In this study, we developed an automated blood sampling system coupled to a simple and sensitive HPLC system to determine plasma concentration of daphnoretin in rats. This method was applied to investigate the pharmacokinetics of daphnoretin in a freely moving rat. Separation of daphnoretin in the rat plasma was achieved using a reversed-phase C18 column (250 mm x 4.6 mm, 5 microm) with a mobile phase of methanol-10 mM NaH2PO4 (adjusted to pH 3.0 with H3PO4) (55:45, v/v), and the flow rate of 1.0 ml/min. The UV detector was set at 345 nm. The automated blood sampling system (DR-II has been applied for blood sampling in a conscious and freely moving rat. The blood samples were centrifuged at 3000 x g for 10 min and the plasma samples were then deproteinized by acetonitrile containing an internal standard (khellin 1 microg/ml). After centrifugation (8000 x g for 10 min), the aliquot of supernatant was injected into the HPLC system for analysis. The concentration-response relationship from the present method indicated linearity over a concentration range of 0.05-1.00 and 1.00-100 microg/ml. Intra- and inter-assay precision and accuracy of daphnoretin fell well within the predefined limits of acceptability (< or = 15%). After daphnoretin (500 mg/kg) was given orally, the maximum concentration was 0.17 microg/ml at the time of 5 min. The oral bioavailability was about 0.15%.

Cromatografia Líquida de Alta Pressão/métodos , Cumarínicos/sangue , Animais , Cumarínicos/farmacocinética , Masculino , Espectrometria de Massas , Ratos , Ratos Sprague-Dawley , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrofotometria Ultravioleta