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1.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 52(5): 740-746, 2021 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-34622586

RESUMO

Nano hydroxyapatite (nHAp), a main component of the inorganic composition of human bones and teeth, is widely used in bone tissue engineering, bone defect repair and replacement, for example, for its biocompatibility, bioactivity, bioaffinity and the ability to induce bone regeneration. Nano hydroxyapatite contains calcium and phosphorus, elements that can be replaced through the normal metabolic channels of the human body. Therefore, after implantation, it can be partially or completely absorbed and replaced by human tissues and can effectively assist bone regeneration, which makes it an ideal material for bone repair. However, traditional nHAp material is brittle and hard to be degraded in human body. In addition, nHAp has poor stability due to its high surface energy and tendency for agglomeration, which causes rapid attenuation of its mechanical strength and limits its clinical application. At present, the mechanical properties and biocompatibility of nHAp can be effectively improved by loading the related growth factors, proteins, peptides and other bioactive molecules, so as to better meet the biological requirements of bone repair materials. However, the traditional physicochemical modification methods are complicated and may interfere with the bioactivity of nHAp. It is simple to biomimetically synthesize nanomaterials by direct utilization of the molecular recognition and self-assemble capabilities of biomolecules or living microorganisms. Furthermore, the properties of the synthesized nanomaterials are stable, and the method has been extensively studied in recent years. Due to the unique crystaline structure and physicochemical properties of nHAp, results of a large number of studies have shown that its affinity with biological molecules can be used to produce bioactive nHAp by biomimetic synthesis methods. Biomimetically synthesized nHAp is expected to become the mainstream bone tissue engineering scaffold material. Analyzing and summarizing the biomimetic synthetic process and the characteristics of different nHAp materials will facilitate further development of bone defect repair materials with better mechanical and biological properties. Herein we reviewed methods of biomimetic synthesis of nHAp based on different biomolecular templates. Furthermore, we also discussed applications of biomimetic synthesized nHAp in bone tissue engineering, which can used as reference information for further research and development of new-generation bone repair biomaterials.


Assuntos
Durapatita , Engenharia Tecidual , Biomimética , Osso e Ossos , Humanos , Tecidos Suporte
2.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 52(5): 799-806, 2021 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-34622596

RESUMO

Objective: To explore the preparation method of copper (Cu)-doped hydroxyapatite (HA) microspheres loaded with vancomycin (Van), and evaluate their antibacterial and osteogenic effects in vitro. Methods: The Cu doped HA microspheres (Cu-HA) with molar doping ratios of 1%, 5%, 10%, and 20% were prepared by hydrothermal synthesis. The microscopic morphology changes were observe with scanning electron microscope. X-ray diffractometer (XRD) was used to study the phase composition and analyze the crystallinity of the sample. Cu-HA with a molar doping ratio of 10% was selected for analysis of the elemental composition of the sample with energy dispersive X-ray spectroscopy (EDS), and was then coated with polydopamine (PDA) as the medium to prepare Cu-HA-PDA. XRD and Fourier infrared spectrometer were used to examine the coating effect of the sample. Van was load on Cu-HA-PDA to prepare Cu-HA-PDA-Van. HA, Cu-HA, HA-PDA, and Cu-HA-PDA-Van were added to α medium at 10 mg/mL to prepare different groups of extract solutions.The main components of the extract solutions were examined, and the Van concentration was checked. We examined the toxic effect of material extract solutions on osteogenic precursor cells and the proliferation and differentiation of bone marrow mesenchymal stem cells, and checked the expression of osteocalcin ( OCN), runt-related transcription factor 2 ( RUNX-2), and alkaline phosphatase ( ALP), the osteogenic related genes. Sterilized HA, Cu-HA, HA-PDA, Cu-HA-PDA, Cu-HA-DPA-Van microsphere materials were prepared, and the colony counting method was used to evaluate the antibacterial effect of the materials for Staphylococcus aureus. Results: Various types of Cu-doped HA (Cu-HA) were successfully synthesized. As the proportion of Cu increased, the morphology gradually changed from being strip or belt-shaped to a uniform spherical shape. Cu-HA of 10% molar doping ratio showed a clearly microspherical shape and a petal-like porous micro-nano morphology on the surface. EDS and XRD analyses showed that the main structure of the material was still made up of hydroxyapatite crystals and Cu was successfully doped with HA. The infrared spectrometer showed that the PDA was successfully coated on the surface of the material. Examination of the main components of the extract solution once again verified that the Cu element had successfully entered and replaced part of the Ca element in the HA. The 10 mg/mL Cu-HA-PDA-Van extract solution contained 0.27 mg/mL of Van. In vitro cell experiments and bone-formation-related gene testing showed that Cu-HA-Van had good biological activity and promoted bone differentiation. The minimum inhibitory concentration (MIC) of Cu-HA-PDA-Van microspheres was 16 µg/mL. Compared with Cu-HA, HA-PDA and pure HA, Cu-HA-Van microspheres had significant and long-lasting antibacterial effects. Conclusion: Cu element was used to control the microscopic morphology of HA, and the Cu-HA-PDA-Van microspheres prepared by successfully coating of PDA and loading of Van had good antibacterial properties and biological activity.


Assuntos
Antibacterianos , Durapatita , Antibacterianos/farmacologia , Cobre , Durapatita/farmacologia , Microesferas , Osteogênese
3.
BMC Musculoskelet Disord ; 22(1): 842, 2021 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-34592965

RESUMO

BACKGROUND: The number of total hip arthroplasties (THAs) performed for patients undergoing dialysis is increasing. However, there are few reports of cementless THA for patients undergoing dialysis. This study investigated the mid-term to long-term results of hydroxyapatite (HA)-coated cementless THA for dialysis patients. METHODS: This single-center, retrospective study enrolled dialysis patients undergoing primary HA-coated cementless THA. A total of 24 patients (30 hips) were included in the final analyses. The Harris hip score and radiographic results were assessed preoperatively and during the final follow-up examination. Postoperative complications and mortality rates were recorded. The mean follow-up period was 109 months (range, 60-216 months). RESULTS: The total Harris hip score significantly improved from 40 to 84 points. The overall cumulative survival rates with revision as the endpoint were 100% at 5 years and 90.4% at both 10 and 15 years. Stress shielding was observed in 24 hips (80%). No deaths were related to the primary THA. Complications included periprosthetic fracture for one patient (3.3%), blood transfusion for nine patients (30%), shunt blockage for two patients (6.7%), deep infection for one patient (3.3%), and dislocation for two patients (6.7%). CONCLUSIONS: HA-coated cementless THA resulted in good mid-term outcomes for patients undergoing dialysis with no mortality risk. However, the procedure involved a relatively high perioperative risk of blood transfusion.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Artroplastia de Quadril/efeitos adversos , Durapatita , Seguimentos , Articulação do Quadril/cirurgia , Prótese de Quadril/efeitos adversos , Humanos , Desenho de Prótese , Falha de Prótese , Diálise Renal , Reoperação , Estudos Retrospectivos , Resultado do Tratamento
4.
Mater Sci Eng C Mater Biol Appl ; 128: 112296, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474847

RESUMO

Hydroxyapatite is widely utilized for different biomedical applications because of its outstanding biocompatibility and bioactivity. Cuttlefish bones, which are available aplenty, are both inexpensive and eco-friendly sources for calcium carbonate. In the present study, cuttlefish bones-derived HAp nanorods have been utilized to fabricate HAp nanocomposites incorporating 1, 3 and 5 wt% each of GO, MWCNTs, GONRs and Ag NPs. Characterization using such techniques as XRD, FTIR, HRSEM and EDS was performed to analyze the physicochemical properties of nanocomposites, and MTT assay, hemolysis, bioactivity and drug release to evaluate the biological properties. The XRD and HRSEM results reveal that crystallite and particle size increase with increasing wt% of carbon nanomaterials and Ag NPs. However, the addition of nanomaterials did not modify the shape of HAp. The MTT assay and hemolysis results suggest GONRs possess better biocompatibility than GO and CNTs due to their smooth edge structure. While adding carbon materials up to 3 wt% caused an increase in the hardness, adding up to 5 wt% of them caused a decrease in the hardness due to the agglomeration of the particles. Biocompatibility and Vicker's hardness studies show that adding carbon nanomaterials up to 3 wt% caused significant improvement in biocompatibility and mechanical properties. Antibacterial activity test was performed to analyze the ability to preclude the formation of biofilms. The results showed better activity for silver-incorporated nanocomposites in the presence of E. coli and S. aureus bacteria. Drug release studies were performed using lidocaine drug and the results showed nearly similar drug release profile for all the samples except HAg3. Finally, nanocomposite HRA3 could be a suitable candidate for biomedical applications since it shows better biological and mechanical properties than GO and MWCNTs nanocomposites.


Assuntos
Durapatita , Nanocompostos , Antibacterianos/farmacologia , Carbono , Escherichia coli , Teste de Materiais , Prata/farmacologia , Staphylococcus aureus
5.
Mater Sci Eng C Mater Biol Appl ; 128: 112298, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474849

RESUMO

Guided Bone Regeneration (GBR) is a widely used process for the treatment of periodontal defects to prevent the formation of surrounding soft tissue at the periodontal defect and to provide hard tissue regeneration. Recently GBR designs have focused on the development of resorbable natural polymer-based barrier membranes due to their biodegradability and excellent biocompatibility. The aim of this study is to fabricate a novel bilayer nanocomposite membrane with microporous sublayer composed of chitosan and Si doped nanohydroxyapatite particles (Si-nHap) and chitosan/PEO nanofiber upper layer. Bilayer membrane was designed to prevent epithelial and fibroblastic cell migration and growth impeding bone formation with its upper layer and to support osteogenic cell bioactivity at the defect site with its sublayer. Microporous and nanofiber layers were fabricated by using freeze-drying and electrospinning techniques respectively. The effect of Si-nHap content on the morphological, mechanical and physical properties of the composites were investigated using SEM, AFM, micro-Ct, compression test, water uptake capacity and enzymatic degradation study. Antimicrobial properties of nanocomposite membranes were investigated with tube dilution and disk diffusion methods. In vitro cytotoxicity of bilayer membranes was evaluated. Saos-2 and NIH/3T3 proliferation studies were carried out on each layer. In vitro bioactivity of Saos-2 and NIH/3T3 cells were evaluated with ALP activity and hydroxyproline content respectively. Results showed that Si-nHap incorporation enhanced the mechanical and physical properties as well as controlling biodegradability of the polymer matrix. Besides, Si-nHap loading induced the bioactivity of Saos-2 cells by enhancing cell attachment, spreading and biomineralization on the material surface. Thus, results supported that designed bilayer nanocomposite membranes can be used as a potential biomaterial for guided bone regeneration in periodontal applications.


Assuntos
Quitosana , Nanocompostos , Animais , Materiais Biocompatíveis/farmacologia , Regeneração Óssea , Durapatita , Membranas Artificiais , Camundongos
6.
Mater Sci Eng C Mater Biol Appl ; 128: 112299, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474850

RESUMO

A novel airflow shearing method was introduced to prepare microspheres efficiently with precisely control of microsphere size and homogeneity. The effects of technical parameters in the formation of the microspheres, such as solution concentration, nozzle size and airflow strength, were investigated. By optimizing the technical parameters (8% PLGA concentration, 27-32 G nozzle size, 6-8 l/min airflow strength), nano-hydroxyapatite and poly(lactide-co-glycolide) nanocomposite (nHA/PLGA) microspheres with a diameter around 250 µm and up to 40 wt% nHA content was prepared successfully. Especially, the microspheres possessed revealed great homogeneity and unique "acorn" appearance with two sides: A hard smooth side as well as a crumpled rough side, generated in the preparation process. Furthermore, the nHA/PLGA microspheres' potential application in bone tissue engineering was studied. In vitro, enhanced proliferation and osteogenic differentiation of the MC3T3-E1 cells was observed on as-prepared nHA/PLGA microspheres with high nHA content. In vivo, the BV/TV value of the microspheres with 20 wt% nHA was up to 75% and similar to the clinical products' performance. Moreover, beside high nHA content, the rough porous surface leads to bone ingrowth, which plays an important role in accelerating bone repair. Therefore, airflow shearing method could be an effective approach to fabricate biocompatible microsphere, and the as-prepared microspheres showed unique surface state and bone repair ability and making them as potential candidates for bone tissue engineering and bone implantation clinical applications.


Assuntos
Durapatita , Nanocompostos , Células Cultivadas , Dioxanos , Ácido Láctico , Microesferas , Osteogênese , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
7.
Mater Sci Eng C Mater Biol Appl ; 128: 112300, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474851

RESUMO

The present experimental study aims to extend know-how on resorbable polycaprolactone/hydroxyapatite (PCL/HA, 70/30 wt%) scaffolds, produced by Laser Powder Bed Fusion (LPBF) technology, to geometrically complex lattice structures and micro porous struts. Using optimized LPBF printing parameters, micro- and macro-porous scaffolds for bone tissue regeneration were produced by regularly repeating in space Diamond (DO) and Rhombic Dodecahedron (RD) elementary unit cells. After production, scaffolds were submitted to structural, mechanical, and biological characterization. The interaction of scaffolds with human Mesenchymal Stem Cells (hMSCs) allowed studying the degradative processes of the PCL matrix. Biomechanical performances and biodegradation of scaffolds were compared to literature results and bone tissue data. Mechanical compression test, biological viability up to 4 days of incubation and degradation rate evidenced strong dependence of scaffold behavior on unit cell geometry as well as on global geometrical features.


Assuntos
Engenharia Tecidual , Tecidos Suporte , Osso e Ossos , Durapatita , Humanos , Lasers , Poliésteres , Porosidade , Pós
8.
Mater Sci Eng C Mater Biol Appl ; 128: 112333, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34474884

RESUMO

Polyetheretherketone (PEEK) was widely applied into fabricating of orthopaedic implants, benefitting its excellent biocompatibility and similar mechanical properties to native bones. However, the inertness of PEEK hinders its integration with the surrounding bone tissue. Here PEEK scaffolds with a series of hydroxyapatite (HA) contents in gradient were manufactured via fused filament fabrication (FFF) 3D printing techniques. The influence of the pore size, HA content and printing direction on the mechanical properties of the PEEK/HA scaffolds was systematically evaluated. By adjusting the pore size and HA contents, the elastic modulus of the PEEK/HA scaffolds can be widely tuned in the range of 624.7-50.6 MPa, similar to the variation range of natural cancellous bone. Meanwhile, the scaffolds exhibited higher Young's modulus and lower compressive strength along Z printing direction. The mapping relationship among geometric parameters, HA content, printing direction and mechanical properties was established, which gave more accurate predictions and controllability of the modulus and strength of scaffolds. The PEEK/HA scaffolds with the micro-structured surface could promote cell attachment and mineralization in vitro. Therefore, the FFF-printed PEEK/HA composites scaffolds can be a good candidate for bone grafting and tissue engineering.


Assuntos
Durapatita , Cetonas , Benzofenonas , Polietilenoglicóis , Polímeros , Porosidade , Impressão Tridimensional , Tecidos Suporte
9.
BMC Musculoskelet Disord ; 22(1): 835, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34587917

RESUMO

BACKGROUND: Aseptic loosening is the most frequent indication for revision of total hip arthroplasty. Revision arthroplasty of acetabular component is a challenge for every surgeon because they have to simultaneously deal with the reconstruction of bone defects, adequate implant geometry and stable fixation. Allografts are the most frequently used materials in reconstruction of bone loss during revision surgeries. Because of an increasing number of revision hip arthroplasties and poor availability of allografts, we decided to use bone graft substitutes in acetabular revisions. METHODS: Between September 2005 and January 2010, 44 revision arthroplasties in 43 patients were performed with the use of bone graft substitutes for acetabular defect reconstruction in revision of total hip arthroplasty. Acetabular bone defects were classified according to Paprosky. Seventeen hips were classified as IIA, 3 hips IIB, 3 hips IIC, 10 hips IIIA and 11 hips IIIB. Acetabular bone defects were reconstructed with tricalcium phosphate/hydroxyapatite bone graft substitute - BoneSave. Clinical and radiological examination was performed after 3 months, 1 year and then annually. Harris hip score was used for clinical evaluation. Survival analysis was performed with Kaplan-Meier method with aseptic loosening as the definition of endpoint. RESULTS: The average follow-up period is 12 (range from 10 to 15) years. During the follow-up, three patients died after 24 months because of causes not related to surgery. None of the patients was lost to follow-up. The evaluation of clinical results revealed an increase in pre-operative HHS from average 38.3 (range 25 to 55) points to average 86.3 (range 45 to 95) points at the most recent follow-up. Radiographic evaluation showed the migration of one revision cage 12 months after surgery. Revision arthroplasty performed after 14 months revealed the partial incorporation of bone graft substitute. There were not any cases of loosening of revision acetabular cup at the most recent follow up examination in the remaining 39 patients. Bone graft substitute was not absorbed in all of these patients. The survival after 10 years amounted to 97.56%. CONCLUSION: Bone graft substitute Bone Save may be suitable for acetabular revision surgery, however preoperative bone defect is critical for success and determining of a surgical technique, so this is multifactorial in this challenge surgery.


Assuntos
Artroplastia de Quadril , Substitutos Ósseos , Prótese de Quadril , Artroplastia de Quadril/efeitos adversos , Fosfatos de Cálcio , Durapatita , Prótese de Quadril/efeitos adversos , Humanos , Falha de Prótese
10.
J Biomed Nanotechnol ; 17(8): 1668-1678, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-34544543

RESUMO

As infection induced by the implant will lead to operation failure, the implant material must be endowed with certain antibacterial properties. Hydroxyapatite (HA) mesoporous microspheres have been widely used in bone repair due to their advantages, including simple synthesis, good osteogenic properties and drug loading capacity. In this study, vancomycin hydrochloride-loaded mesoporous hydroxyapatite microspheres with micro/nanosurface structures were synthesized to increase osteogenic differentiation and antibacterial ability. Phytic acid (IP6) was used as a template to prepare mesoporous hydroxyapatite microspheres composed of fibres, flakes and smooth surfaces by the hydrothermal homogeneous precipitation method, and the corresponding specific surface areas were 65.20 m²/g, 75.13 m²/g and 71.27 m²/g, respectively. Vancomycin hydrochloride (Van) was used as the drug model to study the drug loading and release characteristics of the microspheres, as well as the in vitro antibacterial properties after treatment. In addition, during cocultivation with MC3T3-E1 preosteoblasts, HA microspheres assembled via flakes exhibited better cell compatibility, which promoted cell proliferation, alkaline phosphatase (ALP) activity, and the formation of calcium nodules and increased the expression of osteogenic differentiation-related proteins such as Runx-2, osteopontin (OPN) and collagen I (COL I). These results indicated that the HA microspheres prepared in this experiment have broad application prospects in drug delivery systems and bone repair.


Assuntos
Durapatita , Osteogênese , Antibacterianos/farmacologia , Diferenciação Celular , Durapatita/farmacologia , Microesferas , Vancomicina/farmacologia
11.
Water Sci Technol ; 84(5): 1280-1292, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34534123

RESUMO

The purpose of this work is to produce an alternative cost-effective adsorbent to remove zinc and cadmium from wastewater using hydroxyapatite (HAP) synthesized with hydrothermal method from FGD (Flue gas desulfurization) waste generated by two different coal power plants. The effects of FGD type (Cayirhan and Orhaneli) and molar ratio (H3PO4/CaSO4) (0.6-4.79) on HAP synthesis were investigated. Afterwards, effects of the adsorbent dose (1-2 g/L), heavy metal concentration (30, 40, 50 mg/L) and contact time (1, 2, 3, 4 h) on zinc and cadmium adsorption yield from synthetic wastewater using produced HAP were examined. FGD waste and synthesized FGD-HAP were characterized by X-Ray Diffraction (XRD), Fourier Transformed Infrared Spectroscopy (FT-IR), Scanning Electron Microscope (SEM) and Brunauer-Emmett-Teller (BET) instruments. The zinc and cadmium concentration was studied by Inductively coupled plasma atomic emission spectroscopy (ICP-AES). Maximum zinc adsorption capacity of the Cayirhan FGD-HAP was 49.97 and 49.99 mg/L, Orhaneli FGD-HAP was 49.96 and 49.99 mg/L, for 1 g/L and 2 g/L adsorbent dose, respectively, for 50 mg/L heavy metal concentration and 4 h contact time. Maximum cadmium adsorption capacity of the Cayirhan FGD-HAP was 39.98 and 39.99 mg/L, Orhaneli FGD-HAP was 40 and 39.99 mg/L, for 1 g/L and 2 g/L adsorbent dose, respectively, for 40 mg/L heavy metal concentration and 4 h contact time. Adsorption yields were calculated between 98.53% and 100%. The adsorption data were well explained by a second-order kinetic model, and the Freundlich isotherm model fits the equilibrium data. The adsorption results demonstrated that FGD's waste is an effective source to synthesize HAP, which is used as an adsorbent for zinc and cadmium removal from wastewater due to high adsorption capacity.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Adsorção , Cádmio , Durapatita , Concentração de Íons de Hidrogênio , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier , Poluentes Químicos da Água/análise , Zinco
12.
Mater Sci Eng C Mater Biol Appl ; 129: 112413, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34579922

RESUMO

The scientific community has been doing significant efforts towards engineering new 3D bone models in recent years. Osteocytes are mechanosensitive cells that play significant roles in the maintenance of bone homeostasis. Currently, as far as we know, there are no 3D models that faithfully recapitulate a bone microenvironment capable of promoting the differentiation of osteoblasts towards osteocytes. Besides, in the existing models, the use of human cells does not prevail over the animal cell lines. For so, we propose a 3D model that may have important implications for ongoing efforts towards a better understanding of bone physiology and disease. The main aim of the current work was the promotion of an effective differentiation of osteoblasts into osteocytes by mean of using a 3D model composed of primary human osteoblasts (hOBs) cultured on Gellan Gum-Hydroxyapatite (GG-HAp) matrix under a long-term osteogenic culture. The results revealed that GG-HAp matrix stimulated a fast cell migration/entrapment, attachment, spreading, and mineralization. Moreover, the transition process from osteoblasts to osteocytes was confirmed by the expression of the osteogenic-related (ALP, Runx2, COL I, OC, OPN and OSX) and osteocyte-related (hPDPN) marker throughout the culture time. Overall, the developed 3D model holds a great promise for the treatment of various bone diseases, namely on diagnostic applications and for bone regeneration purposes.


Assuntos
Durapatita , Osteogênese , Animais , Diferenciação Celular , Humanos , Hidrogéis/farmacologia , Osteoblastos , Polissacarídeos Bacterianos
13.
ACS Appl Mater Interfaces ; 13(33): 39142-39156, 2021 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-34433244

RESUMO

The reconstruction of the intra/interfibrillar mineralized collagen microstructure is extremely important in biomaterial science and regeneration medicine. However, certain problems, such as low efficiency and long period of mineralization, are apparent, and the mechanism of interfibrillar mineralization is often neglected in the present literature. Thus, we propose a novel model of biomimetic collagen mineralization that uses molecules with the dual function of cross-linking collagen and regulating collagen mineralization to construct the intrafibrillar and interfibrillar collagen mineralization of the structure of mineralized collagen hard tissues. In the present study completed in vitro, N-2-(3,4-dihydroxyphenyl) acrylamide (DAA) is used to bind and cross-link collagen molecules and further stabilize the self-assembled collagen fibers. The DAA-collagen complex provides more affinity with calcium and phosphate ions, which can reduce the calcium phosphate/collagen interfacial energy to promote hydroxyapatite (HA) nucleation and accelerate the rate of collagen fiber mineralization. Besides inducing intrafibrillar mineralization, the DAA-collagen complex mineralization template can realize interfibrillar mineralization with the c-axis of the HA crystal on the surface of collagen fibers and between fibers that are parallel to the long axis of collagen fibers. The DAA-collagen complex, as a new type of mineralization template, may provide a new collagen mineralization strategy to produce a mineralized scaffold material for tissue engineering or develop bone-like materials.


Assuntos
Acrilamida/química , Materiais Biomiméticos/química , Colágeno/química , Dopamina/química , Osso e Ossos , Cálcio/química , Cálcio/metabolismo , Fosfatos de Cálcio/química , Reagentes para Ligações Cruzadas/química , Cristalização , Durapatita/química , Durapatita/metabolismo , Matriz Extracelular/metabolismo , Humanos , Simulação de Dinâmica Molecular , Polimerização , Medicina Regenerativa , Propriedades de Superfície , Engenharia Tecidual
14.
ACS Biomater Sci Eng ; 7(9): 4463-4473, 2021 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-34387486

RESUMO

Bone fractures are in need of rapid fixation methods, but the current strategies are limited to metal pins and screws, which necessitate secondary surgeries upon removal. New techniques are sought to avoid surgical revisions, while maintaining or improving the fixation speed. Herein, a method of bone fixation is proposed with transparent biopolymers anchored in place via light-activated biocomposites based on expanding CaproGlu bioadhesives. The transparent biopolymers serve as a UV light guide for the activation of CaproGlu biocomposites, which results in evolution of molecular nitrogen (from diazirine photolysis), simultaneously expanding the covalently cross-linked matrix. Osseointegration additives of hydroxyapatite or Bioglass 45S5 yield a biocomposite matrix with increased stiffness and pullout strength. The structure-property relationships of UV joules dose, pin diameter, and biocomposite additives are assessed with respect to the apparent viscosity, shear modulus, spatiotemporal pin curing, and lap-shear adhesion. Finally, a model system is proposed based on ex vivo investigation with bone tissue for the exploration and optimization of UV-active transparent biopolymer fixation.


Assuntos
Pinos Ortopédicos , Fraturas Ósseas , Diazometano , Durapatita , Fraturas Ósseas/cirurgia , Humanos
15.
Langmuir ; 37(36): 10786-10796, 2021 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-34463099

RESUMO

Defects in hydroxyapatite (HA) have attracted increasing research interest due to their significant functions to increase the bioactivity and antibacterial ability of hard-tissue implants. However, little is known about the natural property and functional mechanism of the defects in HA. Herein, we reported on the defect property concerned with the coordination state and charge distribution in Al doped HA, as well as the consequent interface and protein capture ability for improved antibacterial activity. Systemic investigations suggested that Al replacing Ca in HA induced coordination defect with decreased coordination number and bond distance, caused charge transfer and redistribution of surrounding O atom and resulted in an increase in negative charge of coordinated O atoms. These O atoms coordinated with Al further served as docking sites for lysozyme molecules via electrostatic and H-bonding interaction. The capacity of lysozyme adsorption for Al-HA increased approximately 10-fold more than that of HA, which significantly increased the antibacterial activity through lysozyme-catalyzed splitting of cell wall of bacteria. Moreover, in vitro studies indicated that Al-HA materials showed good cytocompatibility. These findings not only provided new insights into the important effect of defects on the performances of HA biomaterials by modulation of the coordination state, charge distribution, and chemical activity, but also proposed a promising method for efficient antibacterial activity of HA biomaterials.


Assuntos
Anti-Infecciosos , Durapatita , Adsorção , Antibacterianos/farmacologia , Muramidase
16.
J Biomed Nanotechnol ; 17(7): 1330-1338, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34446136

RESUMO

The best way in which to prepare scaffolds with good biological properties is an urgent problem in the field of tissue engineering. In this paper we discuss the preparation of nano-hydroxyapatite scaffold of recombinant human bone morphogenetic protein-2 (rhBMP-2) and its application in bone defect repair. rhBMP-2 reagent was dissolved in 1 mol/L sodium dihydrogen phosphate solution, and the rhBMP-2 solution was added to the nano-hydroxyapatite artificial bone with a 100 µL glass micro dropper at the rate of 10 drops/min to obtain Nano-HA/rhBMP-2 composite artificial bone. In in vivo experiments, rabbits were fixed on an operating table, a 2 cm longitudinal incision was made in the middle part of the radial forearm, and the radius was cut with a wire saw and periosteum, 2.5 cm away from the distal radius. After washing the wound with normal saline, Adv-hBMP-2/MC3T3-E1 nano-HA composite artificial bone, MC3T3-E1 nan-HA composite artificial bone, or Nano-HA artificial bone were implanted in different groups. The artificial bone scaffold prepared in this study has a stronger ability to repair bone defects than the alternatives, and is a promising prospect for the clinical treatment of bone defects.


Assuntos
Proteína Morfogenética Óssea 2 , Durapatita , Animais , Regeneração Óssea , Humanos , Osteogênese , Periósteo , Coelhos , Proteínas Recombinantes , Engenharia Tecidual , Tecidos Suporte , Fator de Crescimento Transformador beta
17.
J Biomed Nanotechnol ; 17(7): 1448-1452, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34446147

RESUMO

Cervical spondylosis is a disease that occurs with age and affects the discs and joints in the cervical spine located in the neck. The hydroxyapatite (HA) bone graft substitutes can used as a potential bone-forming agent, however, the efficacy of using HA is challenging in cervical reconstruction. In this regard, nano-based HA was used in this study to explore its sagittal parameters and clinical potency in relative to titanium (TiO2) cage in patient with cervical spondylosis. 50 patients suffering from cervical spondylosis were divided in two groups and were grafted with either TiO2 cage or nano-HA. The sagittal parameters, including cervical spine lateral radiographs (C0-2Coob and C2-7Coob) were taken pre- and post-operation (3-month, one-year and two-year). The clinical potency was also done based on the JOA scores. Angle analysis indicated that the C0-2Cobb and C2-7Cobb angles were significantly changed after the operation in both TiO2 cage and nano-HA groups, whereas no significant changes was determined in nano-HA relative to TiO2 cage condition. Also, it was shown that JOA scores were significantly higher after the operation than pre-operation, indicating a potential cervical reconstruction after surgery in both groups which slightly were higher for nano-HA groups.


Assuntos
Substitutos Ósseos , Fusão Vertebral , Durapatita , Humanos , Titânio , Resultado do Tratamento
18.
Int J Mol Sci ; 22(16)2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34445293

RESUMO

In this research, we synthesize and characterize poly(glycerol sebacate) pre-polymer (pPGS) (1H NMR, FTiR, GPC, and TGA). Nano-hydroxyapatite (HAp) is synthesized using the wet precipitation method. Next, the materials are used to prepare a PGS-based composite with a 25 wt.% addition of HAp. Microporous composites are formed by means of thermally induced phase separation (TIPS) followed by thermal cross-linking (TCL) and salt leaching (SL). The manufactured microporous materials (PGS and PGS/HAp) are then subjected to imaging by means of SEM and µCT for the porous structure characterization. DSC, TGA, and water contact angle measurements are used for further evaluation of the materials. To assess the cytocompatibility and biological potential of PGS-based composites, preosteoblasts and differentiated hFOB 1.19 osteoblasts are employed as in vitro models. Apart from the cytocompatibility, the scaffolds supported cell adhesion and were readily populated by the hFOB1.19 preosteoblasts. HAp-facilitated scaffolds displayed osteoconductive properties, supporting the terminal differentiation of osteoblasts as indicated by the production of alkaline phosphatase, osteocalcin and osteopontin. Notably, the PGS/HAp scaffolds induced the production of significant amounts of osteoclastogenic cytokines: IL-1ß, IL-6 and TNF-α, which induced scaffold remodeling and promoted the reconstruction of bone tissue. Initial biocompatibility tests showed no signs of adverse effects of PGS-based scaffolds toward adult BALB/c mice.


Assuntos
Substitutos Ósseos/síntese química , Decanoatos/química , Durapatita/química , Glicerol/análogos & derivados , Polímeros/química , Engenharia Tecidual/métodos , Tecidos Suporte/química , Animais , Materiais Biocompatíveis/síntese química , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Regeneração Óssea/efeitos dos fármacos , Substitutos Ósseos/química , Substitutos Ósseos/farmacologia , Substitutos Ósseos/uso terapêutico , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/fisiologia , Células Cultivadas , Feminino , Glicerol/química , Humanos , Invenções , Masculino , Teste de Materiais , Camundongos , Camundongos Endogâmicos BALB C , Osteoblastos/efeitos dos fármacos , Osteoblastos/fisiologia , Osteogênese/efeitos dos fármacos , Polímeros/síntese química , Porosidade , Engenharia Tecidual/tendências
19.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 39(4): 419-424, 2021 Aug 01.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-34409797

RESUMO

OBJECTIVES: To investigate the dynamic process of the self-assembly behaviors of a full-length human amelogenin (AM) and its functional fragments tyrosine-rich amelogenin peptide (TRAP) and leucine-rich amelogenin peptide(LRAP) in vitro and its role in hydroxyapatite (HA) crystal formation. METHODS: The full-length human AM and its functional fragments, TRAP and LRAP, were reassembled and purified in vitro. The protein solution of 100 µg‧mL-1, pH=8, was prepared in Tris-HCl and incubated at room temperature for 1-15 min. Their self-assembly behaviors were observed and compared under a transmission electron microscope (TEM). The full-length AM was added to artificial saliva and incubated for 3 days. A scanning electron microscope (SEM) was used in observing the morphology of the induced new crystals. Then, TARP and LRAP were added. The resulting solution was incubated for 3 days and then observed again. RESULTS: When pH=8, the full-length human AM and TRAP assembly started spontaneously and formed "nanospheres" after 15 min.The nanospheres formed by TRAP existed independently, with a uniform size but without obvious internal structures. The full-length AM was assembled hierarchically, which formed "nanospheres" and further extended in all directions, formed a chain structure, and then aggregated into a net. The self-assembly behavior of LRAP was not obvious. Proteins mostly existed in the form of monomers without "nanosphere" formation. Only few oligomers were observed. The full-length AM was induced independently for 3 days to form rod-shaped HA crystals. TRAP and LRAP proteins were added, after 3 days the crystal elongation was obvious in the c axis, but the growth in plane A and plane B was poor. CONCLUSIONS: The self-assembly and mineralization behaviors of full-length human AM, TRAP, and LRAP were consistent with the directional growth mechanism of HA crystals in vivo, providing a theoretical basis for the role of the fragments in the growth and maturation of HA crystals.


Assuntos
Proteínas do Esmalte Dentário , Amelogenina , Durapatita , Humanos
20.
Pan Afr Med J ; 38: 408, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34381552

RESUMO

Hydroxyapatite crystal deposition disease (HADD) of the hand and wrist is rare but can cause acute inflammatory syndromes that mimic infectious arthritis. These symptoms, which rapidly resolve with systemic anti-inflammatory drugs, are a source of diagnostic errors and inappropriate treatment. It is of crucial importance to make the diagnosis in order to avoid iatrogenic surgical management. The aim of this study was to determine the clinical and radiographic signs and the key features on which diagnosis depends. Treatment effectiveness and the course of the disease were also examined. Between 1992 and 2008, 12 patients consulted for an isolated acute local inflammatory syndrome of the hand or wrist, which was accompanied by a unique radiographic picture of calcific density. All patients were reassessed clinically and radiographically with a minimum follow-up of 2 years. All patients had presented with acute local inflammatory syndromes. Nine patients had edema and 8 had swelling and erythema. No patient had fever. The course was favorable in 11 patients and one patient required surgery. No patient had a recurrence at the mean final follow-up of 90 ± 64 months. The symptoms associated with hydroxyapatite crystal deposits suggest septic arthritis with acute joint inflammation. The radiological appearance is characteristic and corrects the diagnosis. Oral anti-inflammatory treatment gives more rapid spontaneous improvement, with complete and long-lasting resolution.


Assuntos
Calcinose/diagnóstico por imagem , Durapatita/metabolismo , Mãos/diagnóstico por imagem , Punho/diagnóstico por imagem , Adulto , Idoso , Anti-Inflamatórios/administração & dosagem , Artrite Infecciosa/diagnóstico , Calcinose/patologia , Calcinose/terapia , Edema/etiologia , Feminino , Seguimentos , Mãos/patologia , Humanos , Inflamação/diagnóstico por imagem , Inflamação/patologia , Masculino , Pessoa de Meia-Idade , Radiografia , Estudos Retrospectivos , Punho/patologia
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