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Objective@# To investigate the osteogenic effect of β-tricalcium phosphate (β-TCP) and bone morphogenetic protein-2 (BMP-2) in the repair of the alveolar cleft.@*Methods @# Fifty-nine patients with unilateral alveolar cleft who visited Capital Medical University School of Stomatology from January 2016 to May 2021 were included. They were divided into three groups according to the different bone repair materials: autologous bone, β-TCP and BMP-2 +β-TCP. The preoperative and postoperative CBCT data of the patients were imported into Mimics 21.0 software. The preoperative volume of the bone defect and the new volume of bone formation were calculated by the three-dimensional reconstruction method. The osteogenesis rate was calculated to evaluate the osteogenesis effect@*Results@#The wounds in the three groups healed well after the operation, without implant material discharge, infection, dehiscence, rejection or other symptoms. Twelve months after the operation, CBCT scanning and three⁃dimensional reconstruction images of the three groups of patients showed the formation of new bone bridges in the alveolar ridge fissure area. The image density of the new bone tissue was not significantly different from that of normal bone tissue, and the continuity of the maxilla was re⁃ stored to varying degrees. The bone rate of autogenous bone was 65.00% ± 16.66%, β⁃ TCP group and BMP⁃2+ β⁃ The bone composition rate of TCP was 69.82% ± 17.60%, 71.35% ± 17.51%, respectively, and there was no significant dif⁃ ference compared with the autogenous bone group (P = 0.382, P = 0.244). The β⁃TCP and BMP⁃2+ β⁃TCP groups had no significant differences in bone rate (P = 0.789). @*Conclusion@#β⁃TCP could be used to replace autologous bone for alveolar cleft repair. The addition of BMP⁃2 to β⁃TCP did not significantly improve the osteogenesis rate.
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Objective @#To investigate the role and mechanism of bone formation caused by the ratio of advanced platelet-rich fibrin (A-PRF) and β-tricalcium phosphate (β-TCP) in rabbit femur defect model, which provides a new idea for clinical treatment of bone defect.@*Methods @#Twenty-four New Zealand white rabbits were divided into model group, 1∶1 complex group (A-PRF∶β-TCP=1∶1), 2∶1 complex group (A-PRF∶β- TCP=2∶1) and 4∶1 complex group (A-PRF∶β- TCP=4∶1）, with 6 rabbits in each group. Femoral defect models were constructed in each group. In the composite group, the bone defect was filled with composite material, while in the model group, no material was filled. After 8 weeks, the animals were euthanized and specimens were collected. Bone mineral density (BMD), bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular separation (Tb.SP) and trabecular number (Tb.N) in femoral defect tissue were measured by micro-CT and photographed. Hematoxylin - eosin staining was used to detect the pathological changes of new bone tissue. The morphological changes of the new bone tissue were observed by scanning electron microscopy. Determination of phospho-mitogen activated protein kinase p38 (p-p38MAPK), CCAAT/enhancer binding protein homologous protein (CHOP) and phospho-cysteine aspartic protease-3 (p-Caspase3) in newborn femur by ELISA. The mRNA expressions of osteoprotegerin (OPG), bone morphogenetic protein-2 (BMP-2), receptor activator of nuclear factor kappa-B ligand (RANKL) and p38MAPK were detected by real-time quantitative PCR. The expression of OPG, BMP-2, RANKL, p-p38MAPK and p-Caspase3 protein in the new bone tissue was observed by immunohistochemistry. @*Results @#In the model group, bone formation in the femoral defect area was slow and osteogenic quality was poor. Compared with the model group, the bone formation and neocapillaries of femoral defect area in the complex group was good, BMD, BV.TV, Tb.Th, Tb.N were increased, and Tb.Sp were decreased, the expressions of p-p38MAPK, CHOP and p-Caspase3 were decreased, and the mRNA and protein expressions of OPG and BMP-2 were increased. The mRNA expression of RANKL and p38MAPK was decreased. Apoptosis in new bone tissue of each group showed the lowest apoptosis rate in samples of the 2∶1 complex group (P<0.05); A-PRF: β-TCP=2∶1 ratio has the best osteogenic effect. @*Conclusion@#The complex composed of A-PRF and β-TCP can promote the expression of OPG, inhibit the expression of RANKL and phosphorylation of p38MAPK, reduce the apoptosis of new bone tissue cells, and promote osteogenic differentiation.
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OBJECTIVE@#To study the preparation and properties of the hyaluronic acid (HA)/α-calcium sulfate hemihydrate (α-CSH)/β-tricalcium phosphate (β-TCP) material (hereinafter referred to as composite material).@*METHODS@#Firstly, the α-CSH was prepared from calcium sulfate dihydrate by hydrothermal method, and the β-TCP was prepared by wet reaction of soluble calcium salt and phosphate. Secondly, the α-CSH and β-TCP were mixed in different proportions (10∶0, 9∶1, 8∶2, 7∶3, 5∶5, and 3∶7), and then mixed with HA solutions with concentrations of 0.1%, 0.25%, 0.5%, 1.0%, and 2.0%, respectively, at a liquid-solid ratio of 0.30 and 0.35 respectively to prepare HA/α-CSH/ β-TCP composite material. The α-CSH/β-TCP composite material prepared with α-CSH, β-TCP, and deionized water was used as the control. The composite material was analyzed by scanning electron microscope, X-ray diffraction analysis, initial/final setting time, degradation, compressive strength, dispersion, injectability, and cytotoxicity.@*RESULTS@#The HA/α-CSH/β-TCP composite material was prepared successfully. The composite material has rough surface, densely packed irregular block particles and strip particles, and microporous structures, with the pore size mainly between 5 and 15 μm. When the content of β-TCP increased, the initial/final setting time of composite material increased, the degradation rate decreased, and the compressive strength showed a trend of first increasing and then weakening; there were significant differences between the composite materials with different α-CSH/β-TCP proportion ( P<0.05). Adding HA improved the injectable property of the composite material, and it showed an increasing trend with the increase of concentration ( P<0.05), but it has no obvious effect on the setting time of composite material ( P>0.05). The cytotoxicity level of HA/α-CSH/β-TCP composite material ranged from 0 to 1, without cytotoxicity.@*CONCLUSION@#The HA/α-CSH/β-TCP composite materials have good biocompatibility. Theoretically, it can meet the clinical needs of bone defect repairing, and may be a new artificial bone material with potential clinical application prospect.
Subject(s)
Calcium Phosphates , Bone and Bones , PhosphatesABSTRACT
Aims and Objective: The present study aimed to evaluate 2 bone graft materials, that is, biphasic hydroxyapatite and ??tricalcium phosphate, in the treatment of periodontal vertical bony defects. In term of attachment level, probing depth and radiographic bone level changes. Also, a new digital method of radiographic assessment was used for measurement of vertical bone defect. Material and Methods: Ten subjects with periodontitis and having two or more vertical bony defects were enrolled in the study. Patients were classified randomly into 2 groups. Group I consisted of the experimental site where defect was filled with biphasic hydroxyapatite and ??tricalcium phosphate graft and Group II consisted of control site where only the open flap debridement (OFD) was carried out. Clinical parameters were evaluated at baseline, 3 and 6 months; Radiographs were taken at baseline and 6 months after surgery. Results: Overall, by the end of 6 months, biphasic hydroxyapatite and ??tricalcium phosphate and OFD treatment groups exhibited a significant reduction in probing depth almost by 75% and gain in clinical attachment level at follow?up. In the biphasic hydroxyapatite and ??tricalcium phosphate group, radiographic bone level gain appeared to be greater than in the OFD group. Conclusion: In the present study, biphasic hydroxyapatite and ??tricalcium phosphate have shown promising results and have showed reduction in probing depth, a resolution of osseous defects and gain in clinical attachment level when compared to open flap debridement.
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Bone defects caused by trauma, infection, tumor and other factors is a thorny problem in orthopedic clinic, and promoting bone repair and regeneration is the key and difficult point of treatment. In addition to autologous bone grafting, artificial bone materials are often used for large bone defects. β-tricalcium phosphate has good biocompatibility, bone conduction and bone induction properties, and has been studied deeply because of its excellent drug delivery performance and has shown broad application prospects. In this paper, the author will summarize the research progress of β-tricalcium phosphate composites loaded with different drugs in the treatment of bone defects caused by trauma, infection and tumor.
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Abstract Nanoscale biomaterials are commonly used in a wide range of biomedical applications such as bone graft substitutes, gene delivery systems, and biologically active agents. On the other hand, the cytotoxic potential of these particles hasn't yet been studied comprehensively to understand whether or not they exert any negative impact on the cellular structures. Here, we undertook the synthesis of beta-tricalcium phosphate (ß-TCP) and biphasic tricalcium phosphate (BCP) nanoparticles (NPs) and determine their concentration-dependent toxic effects in human fetal osteoblastic (hFOB 1.19) cell line. Firstly, BCP and β-TCP were synthesized using a water-based precipitation technique and characterized by X-Ray Diffraction (XRD), Raman Spectroscopy, and Transmission Electron Microscopy (TEM). The cytological effects of β-TCP and BCP at different concentrations (0-640 ppm) were evaluated by using 3- (4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) assays. The total oxidative status (TOS) parameter was used for investigating oxidative stress potentials of the NPs. In addition, the study assessed the DNA damage product 8-hydroxy-2′-deoxyguanosine (8-Oxo-dG) level in hFOB 1.19 cell cultures. The results indicated that the β-TCP (above 320 ppm) and BCP (above 80 ppm) NPs exhibited cytotoxicity effects on high concentrations. It was also observed that the oxidative stress increased relatively as the concentrations of NPs increased, aligning with the cytotoxicity results. However, the NPs concentrations of 160 ppm and above increased the level of 8-OH-dG. Consequently, there is a need for more systematic in vivo and in vitro approaches to the toxic effects of both nanoparticles.
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Abstract This study aimed to evaluate, in vitro and in vivo, the biocompatibility of experimental methacrylate-based endodontic sealers containing α-tricalcium phosphate (α-TCP) or nanostructured hydroxyapatite (HAp). Experimental methacrylate-based dual-cure sealers with the addition of α-TCP or HAp, at 10%wt were formulated and compared to AH Plus (AHP). Cell viability was assessed by 3-(4,5-dimethyl-thiazoyl)-2,5-diphenyl-tetrazolium bromide (MTT), and sulforhodamine B (SRB). Sealers were implanted in rats' subcutaneous tissue and histologically evaluated. Bioactivity was assessed by alkaline phosphatase enzyme activity (ALP) and Alizarin Red (AR), using apical papillary cells (SCAPs), and by the bone deposition measured in surgical cavities on rats' femur filled with AH Plus or α-TCP. In both viability assays, HAp and AHP sealers were similar, and α-TCP presented lower viability compared to the others at MTT assay (p<0.05). A gradual decrease of the inflammatory response according to the periods was observed and AHP was the only that presented giant cells (7-day period). Collagen fibers condensation increased according to the periods, with no differences among sealers. There was an increase at ALP activity and mineralized nodules deposition according to periods. HAp and α-TCP presented higher values for ALP activity at 5 days and at 5, 10, and 15 days for AR and were different from AHP (p<0.05). α-TCP presented superior values at 10 and 15 days compared to HAp and AHP for AR (p<0.05). At 90 days, α-TCP and control (empty cavity) showed high bone deposition compared to AHP (p<0.05). α-TCP and HAp, in a methacrylate-based sealer, presented biocompatibility and bioactivity, with the potential to be used as endodontic sealers in clinical practice. Further investigations are required to gain information on the physicochemical properties of these sealers formulation before its clinical implementation.
Resumo O objetivo deste estudo foi avaliar a biocompatibilidade de cimentos endodônticos experimentais à base de metacrilato contendo fosfato α-tricálcico ou hidroxiapatita nanoestruturada in vitro e in vivo. Cimentos experimentais de cura dual à base de metacrilato com a adição de fosfato de α-tricálcico (α-TCP) ou hidroxiapatita (HAp), a 10% em peso, foram formulados e comparados com AH Plus (AHP). Viabilidade celular foi avaliada por brometo de 3- (4,5-dimetil-tiazoil) -2,5-difenil-tetrazólio (MTT) e sulforodamina B (SRB). Cimentos foram implantados no tecido subcutâneo dos ratos e avaliados histologicamente. Bioatividade foi avaliada pela atividade da enzima fosfatase alcalina (ALP) e Alizarin Red (AR) utilizando células da papila apical (SCAPs) e pela deposição óssea, medida em cavidades cirúrgicas no fêmur de ratos preenchidos com AH Plus e α-TCP. Nos dois ensaios de viabilidade, HAp e AHP não apresentaram diferenças estatísticas, α-TCP apresentou menores resultados de viabilidade para o ensaio MTT (p <0,05). Resultados histológicos mostraram que houve uma diminuição do conteúdo inflamatório de acordo com os períodos, e o AHP foi o único grupo que apresentou células gigantes (período de 7 dias). A condensação das fibras colágenas aumentou conforme os períodos, sem diferenças entre os grupos. Houve aumento da atividade da ALP e deposição de nódulos mineralizados de acordo com os períodos. HAp e α-TCP apresentaram maiores valores para a atividade de ALP em 5 dias e em 5, 10 e 15 dias para AR, com diferença para o AHP (p <0,05). O α-TCP apresentou valores superiores aos 10 e 15 dias quando comparado ao HAp e AHP para AR (p <0,05). Aos 90 dias, α-TCP e controle (cavidade vazia) apresentaram maior deposição de tecido ósseo quando comparado ao AHP (p <0,05). α-TCP e HAp, presentes nos cimentos à base de metacrilato, apresentaram biocompatibilidade e potencial para serem utilizados como seladores endodônticos na prática clínica. Investigações adicionais são necessárias para obter informações sobre as propriedades físico-químicas dessas formulações de cimentos antes de sua implementação clínica.
Subject(s)
Animals , Rats , Root Canal Filling Materials , Materials Testing , Calcium Phosphates , Cell Survival , Epoxy Resins , MethacrylatesABSTRACT
Abstract These case reports aimed to describe the management of lateral perforation in the middle cervical third of the root in two maxillary incisors with pulp canal calcification using Bio-C Repair, with safe and viable clinical treatment strategies. Digital radiographic exams were obtained with different angles and analyzed using different filters. Cone-beam computed tomography (CBCT) images were requested to show the actual position of the canal, location of the perforation, and guide the strategic planning of the case. Subsequently, cavity access was prepared with the aid of dental operating microscopy. After perforation was identified, granulation tissue was removed and the original canal was identified and then dressed with calcium hydroxide. In the second visit, the perforation was filled with Bio-C Repair and the canal system filled with gutta-percha points and a root canal sealer (Bio-C Sealer). The teeth were restored with glass fiber post, 4 mm beyond the perforation level, and provisory crowns. Both teeth treated as described above were functional and asymptomatic with a 1-year clinical and radiographic assessment. The Bio-C Repair is suggested as a new cement option for the management of lateral canal perforations, with effective results as observed after a one-year follow-up.
Resumo O presente relato de caso teve como objetivo descrever o manejo da perfuração lateral no terço médio cervical da raiz em dois incisivos superiores com calcificação pulpar utilizando o Bio-C Repair, com estratégias de tratamento clínico seguras e viáveis. Radiografias digitais foram obtidas em diferentes ângulos e analisadas com diferentes filtros. Imagens de tomografia computadorizada de feixe cônico (TCFC) foram solicitadas para mostrar a real posição do canal e a localização da perfuração, e orientar o planejamento estratégico do caso. Posteriormente, o acesso à cavidade foi preparado com auxílio de microscopia cirúrgica. Após a identificação da perfuração, o tecido de granulação foi removido, o canal original foi identificado e, em seguida, recebeu medicação intracanal à base de hidróxido de cálcio. Na segunda visita, a perfuração foi selada com Bio-C Repair e o sistema de canais obturado com cones de guta-percha e cimento endodôntico (Bio-C Sealer). Os dentes foram restaurados com pino de fibra de vidro, 4 mm além do nível da perfuração, e coroas provisórias. Ambos os dentes tratados conforme descrito acima se mostraram funcionais e assintomáticos na avaliação clínica e radiográfica de 1 ano. O Bio-C Repair é sugerido como uma nova opção de cimento endodôntico para o manejo de perfurações laterais, com resultados efetivos observados após um ano de acompanhamento.
Subject(s)
Humans , Root Canal Filling Materials , Root Canal Preparation , Root Canal Obturation , Calcium Hydroxide , Dental Pulp Cavity , Gutta-PerchaABSTRACT
Background: Dental caries is one of the most prevalent posteruptive bacterial infections worldwide, characterized by a progressive demineralization process that affects the mineralized dental tissues. Although the decline of dental caries prevalence can be attributed to the widespread use of dentifrices that contain fluoride, yet there is a need for an advanced alternative nonfluoride remineralizing dentifrice. Yet, there is a need for an advanced alternative nonfluoride remineralizing dentifrice. Aim: The aim of this study was to evaluate and compare the remineralizing effect of nonfluoride-based and herbal-based pediatric dentifrice in demineralized primary teeth with an ideal in vitro method of pH cycling and evaluating the values under Polarized Light Microscope (Olympus BX43) using image analysis software (ProgRes, Speed XT core3). Materials and Methods: A total of 30 tooth samples were collected and placed in the demineralizing solution for 96 h to produce a demineralized lesion of approximately 100 ?m, and then cut longitudinally into 60 sections that were randomly assigned to two groups with 27 samples each, Group A – nonfluoride-based dentifrice (Mee Mee®), Group B – herbal-based dentifrice (Mamaearth™), after which they were subjected to pH cycling for 7 days along with dentifrice slurry preparation. The sections were evaluated under the polarizing light microscopy for remineralizing efficacy. The lesion depth was measured and tabulated to be sent for statistical analysis. Results: The mean demineralization value for nonfluoride and herbal-based dentifrice groups were 7.8730 ?m and 28.3174 ?m, respectively. Hence, it can be inferred that since lesion depth measured was lesser in nonfluoride than herbal-based dentifrice, remineralization has occurred in the nonfluoride-based dentifrice group. Conclusion: Nonfluoride-based dentifrice showed significant results in remineralizing the demineralized lesion, while herbal-based dentifrice showed poor efficiency in remineralizing the demineralized lesion.
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Objective: This study aimed to examine differences in platelet-rich plasma (PRP) soak-loaded volumes of β-tricalcium phosphate (β-TCP) with or without a unidirectional porous structure.Materials and Methods: Leukocyte-rich PRP was extracted from 15 healthy volunteers by centrifugation. Two types of artificial bones were soaked for either ten seconds or ten minutes. The volume ratios of PRP soak-loaded onto the artificial bone and soaked area ratios were evaluated. Statistical analyses were performed using the Tukey-Kramer HSD test and the Games-Howell method. A P-value of <0.05 was considered statistically significant.Results: Regardless of the soaking time, the PRP soak-loaded volume ratio and soaked area ratio were significantly higher in the unidirectional porous β-TCP (UDPTCP) group than in the spherical porous β-TCP (SPTCP) group.Conclusion: PRP can be soak-loaded faster and in larger amounts onto UDPTCP compared to SPTCP. Understanding the basic biology of β-TCP soak-loaded with PRP can help develop more novel and effective β-TCP treatments for orthopedic surgery.
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Introduction: Unidirectional porous β-tricalcium phosphate (UDPTCP) consists of a novel porous artificial bone that is structurally different from conventional artificial bone comprised of spherical porous β-tricalcium phosphate (SPTCP).Case presentation: We present our first four clinical cases of opening-wedge high tibial osteotomy (OWHTO) using UDPTCP and SPTCP together. The patients’ mean age was 54.5 ± 5.9 years, and the mean observation period was 20.8 ± 2.8 months. In OWHTO, two wedge shaped pieces of UDPTCP and SPTCP were cut to fit the gap and implanted parallel to each other in the anterior and posterior parts, respectively. We evaluated the correction loss and bone remodeling for UDPTCP and SPTCP over time using radiography and computed tomography, and evaluated the clinical outcomes.Conclusion: There was no correction loss reported in any case, and early bone remodeling was observed with UDPTCP. All patients achieved satisfactory clinical results with no adverse events.
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Abstract This study evaluated the biocompatibility, biomineralization, and collagen fiber maturation induced by Resorbable Tissue Replacement (RTR®; β-tricalcium phosphate [TCP]), Bioglass (BIOG; bioactive glass), and DM Bone® (DMB; hydroxyapatite and β-TCP) in vivo. Sixty-four polyethylene tubes with or without (control group; CG) materials (n=8/group/period) were randomly implanted in the subcutaneous tissue of 16 male Wistar rats (four per rat), weighting 250 to 280 g. The rats were killed after 7 and 30 days (n=8), and the specimens were removed for analysis of inflammation using hematoxylin-eosin; biomineralization assay using von Kossa (VK) staining and polarized light (PL); and collagen fiber maturation using picrosirius red (PSR). Nonparametric data were statistically analyzed by Kruskal-Wallis and Dunn tests, and parametric data by one-way ANOVA test (p<0.05). At 7 days, all groups induced moderate inflammation (p>0.05). At 30 days, there was mild inflammation in the BIOG and CG, and moderate inflammation in the RTR and DMB groups, with a significant difference between the CG and RTR (p<0.05). The fibrous capsule was thick at 7 days and predominantly thin at 30 days in all groups. All materials exhibited structures that stained positively for VK and PL. Immature collagen fibers were predominant at 7 and 30 days in all groups (p>0.05), although DMB exhibited more mature fibers than BIOG at 30 days (p<0.05). RTR, BIOG, and DMB were biocompatible, inducing inflammation that reduced over time and biomineralization in the subcutaneous tissue of rats. DMB exhibited more mature collagen fibers than BIOG over a longer period.
Resumo Este estudo avaliou a biocompatibilidade, biomineralização e maturação das fibras de colágeno induzidas por Resorbable Tissue Replacement (RTR®; fosfato β-tricálcico [TCP]), Bioglass (BIOG; vidro bioativo) e DM Bone® (DMB; hidroxiapatita e β-TCP) in vivo. Sessenta e quatro tubos de polietileno com ou sem (grupo controle; GC) os materiais (n=8/grupo/período) foram implantados aleatoriamente em tecido subcutâneo de 16 ratos machos Wistar (quatro por rato), pesando entre 250 a 280g. Os ratos foram mortos após 7 e 30 dias (n=8), e as amostras foram removidas para análise da inflamação utilizando hematoxilina-eosina; avaliação da biomineralização utilizando coloração de von Kossa (VK) e luz polarizada (LP); e maturação das fibras colágenas, utilizando picrosirius red (PSR). Os dados não-paramétricos foram analisados pelos testes de Kruskal-Wallis e Dunn, e os paramétricos pelo teste de one-way ANOVA (p<0.05). Aos 7 dias, todos os grupos induziram inflamação moderada (p>0,05). Aos 30 dias, houve inflamação leve nos grupos BIOG e GC, e inflamação moderada nos grupos RTR e DMB, com diferença significativa entre os GC e RTR (p<0,05). A cápsula fibrosa foi espessa aos 7 dias, e predominantemente fina aos 30 dias em todos os grupos. Todos os materiais exibiram estruturas positivas para VK e LP. Fibras colágenas imaturas foram predominantes aos 7 e 30 dias em todos os grupos (p>0,05), embora o DMB exibiu fibras mais maduras do que o BIOG aos 30 dias (p<0,05). RTR, BIOG e DMB foram biocompatíveis, induzindo inflamação que reduziu com o tempo, e biomineralização no tecido subcutâneo de ratos. O DMB exibiu mais fibras colágenas maduras do que o BIOG em período mais longo.
Subject(s)
Animals , Male , Rats , Root Canal Filling Materials , Biomineralization , Oxides , Biocompatible Materials , Materials Testing , Ceramics , Collagen , Rats, Wistar , Silicates , Calcium Compounds , Aluminum Compounds , Subcutaneous TissueABSTRACT
@#Introduction: Melatonin (MEL) loaded alginate-chitosan/beta-tricalcium phosphate (Alg-CH/β-TCP) composite hydrogel has been formulated as a scaffold for bone regeneration. MEL in the scaffold was anticipated to accelerate bone regeneration. The objective of this study is to observe signs of systemic toxicity and physical changes on surface defected bone for bone regenerative performance of the composite. Methods: The proximal-medial metaphyseal cortex of the left tibia of New Zealand white rabbit was the surgical site of the defect. A total of nine rabbits were randomly allocated to three groups; Group I; implanted with MEL loaded Alg-CH/β-TCP, Group II; Alg-CH/β-TCP and Group III defects were sham control. The rabbits were daily observed to determine systemic toxicity effects by composites. The physical changes to implanted site were observed using digital x-ray radiography and computerized tomography at weeks 0, 2, 4, 6 and 8 of post-implantation. Results: There were no clinical signs of systemic toxicity for all groups of rabbits. Digital radiography did not show adverse effects to the bone. Computerized tomography showed reduction in the area size and depth volume of the implantation site, but accelerated regeneration within the 8 weeks was not significantly different (P<0.05) between the groups. Conclusion: Overall, the study suggests that Alg-CH/β-TCP composite scaffolds with and without the addition of MEL are compatible to bone. The composite scaffolds reduced the area size and depth volume of the implanted site within the 8-week duration. However, no remarkable difference in the accelerated reduction of area size and depth volume was observed.
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BACKGROUND: Simple posterolateral tibial plateau collapse fracture is very rare in the clinic. The displaced collapse fracture in this area must be anatomically reduced, filled with suitable materials, and fixed with internal fixators. OBJECTIVE: To evaluate the stability, clinical results and biocompatibility of modified posterolateral approach to treat simple posterolateral tibial plateau collapse fracture with beta-tricalcium phosphate combined with T-shaped locking plate. METHODS: Fifteen patients with simple posterolateral tibial plateau collapse fractures who received surgical treatment between June 2013 and December 2017 in Zhangjiagang Hospital Affiliated to Soochow University. These patients included 8 males and 7 females, aged 25-53 years. All of them received surgical treatment with beta-tricalcium phosphate combined with T-shaped locking plate through the modified posterolateral approach. After surgery, they were followed up for 12 months. X-ray examination was performed to evaluate fracture healing and internal fixation. Reduction effect was evaluated by Rasmussen radiology score. Knee function and stability were evaluated by HSS knee function score, Lachman test, pivot-shift test and lateral stress test. This study was approved by Medical Ethics Committee, Zhangjiagang Hospital Affiliated to Soochow University, China (approval No. 201305KS001). RESULTS AND CONCLUSION: (1) All patients underwent anatomical reduction of knee fractures, and the fracture healing time was 9-14 weeks. At 12 months after surgery, p-tricalcium phosphate was completely absorbed and replaced by new bone, and repair of bone defect was satisfactory. (2) There were no significant differences in posterior tibia angle, varus angle, Rasmussen imaging collapse score and Rasmussen imaging total score between 12 months after surgery and immediately after surgery in 15 patients (P > 0. 05). (3) At 12 months after surgery, the HSS score of the knee joint was 89-100, and Lachman test, pivot-shift test and lateral stress test results were negative in 15 patients. (4) During the follow up period, infection around implants, allergic reaction, immune reaction, or rejection reaction was not observed. (5) These findings suggest that treatment of simple posterolateral tibial plateau collapse fracture through the modified posterolateral approach with p-tricalcium phosphate combined with T-shaped locking plate exhibits good repair effects and biocompatibility.
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BACKGROUND: Adipose-derived stem cells are easy to access and have strong proliferative capacity, which are considered as ideal seed cells for bone defect repair. The bone tissue engineering research progress reveals that bioscaffold material modification can directly regulate the osteogenic differentiation of stem cells. OBJECTIVE: To review various biological scaffold materials that can regulate the osteogenic differentiation of adipose-derived stem cells. METHODS: The first author searched the articles in CNKI, WanFang, VIP, PubMed, Embase and Web of Science databases published from January 2016 to May 2019. The search terms were “adipose derived stem cells, scaffold, osteogenic, metal, Ti” in Chinese and English, respectively. Finally 62 eligible articles were selected. RESULTS AND CONCLUSION: Scaffold materials for bone tissue engineering are classified into inorganic materials (hydroxyapatite, tricalcium phosphate, bioglass, titanium, and magnesium), natural polymer materials (collagen, silk fibroin, and chitosan) and synthetic polymer materials (polycaprolactone, polylactic acid, polyglycolic acid and poly(lactic-co-glycolic acid)). The studies on materials that interact with cells to guide their biological response and bone differentiation are increasing. But how to create a safe, rational, and close to the micro-environment of cell growth in vivo is a challenge. Modification of bioscaffold materials can directly regulate osteogenic differentiation of stem cells. Moreover, vascularization and post-implantation infections are issues of concern.
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BACKGROUND: Dentin particles, tricalcium phosphate/collagen protein composites and Bio-oss particles can repair jaw defects, but the excellent osteogenic effect is not clear. OBJECTIVE: To compare osteogenic effects of three different bone graft materials on mandibular defects in beagle dogs. METHODS: Eight 1-year-old beagles were selected. A boxed bone defect area of 10 mm × 8 mm × 2 mm was prepared at the bilateral mandibular external oblique line and randomly divided into four groups with four bone defect models in each group. Undemineralized dentin particles were implanted in group A; tricalcium phosphate/ collagen protein composite materials were implanted in group B; Bio-oss particles were implanted in group C; and group D was used as blank control. Three months after transplantation, the samples were taken for histological observation. The experimental animals were approved by the Ethics Committee of the Experimental Animal Center of Dalian Medical University. RESULTS AND CONCLUSION: (1) In group A, dentin particles were slightly absorbed, surrounded by new bone tissue; new bone trabeculae and capillaries could be seen, and a large number of fibrous connective tissue surrounded dentin particles in the central area of bone graft. In group B, a small number of new bone trabeculae and osteoblasts could be seen; a large number of powdered β-tricalcium phosphate particles and a small amount of inflammatory cells could be seen in the fibrous connective tissue; and some β-tricalcium phosphate particles were surrounded by new bone tissue. Bone marrow cavity could be seen in the new bone. In group C, some Bio-oss particles were surrounded by new bone tissue; some Bio-oss particles were wrapped by surrounding fibrous connective tissue, and fibers, particles and new bone were intertwined. There was no new bone formation in group D, and many capillaries could be seen in a large number of fibrous connective tissue. (2) The rate of new bone formation in groups A, B and C was higher than that in group D (P < 0.05); the rate in groups A and C was higher than that in group B (P < 0.05). (3) The results show that all the three kinds of bone graft materials can promote the formation of new bone. The short-term osteogenic effects of undecalcified xenogeneic dentin particles and Bio-oss particles are better than tricalcium phosphate/collagen protein composites, but the long-term effects need to be further observed.
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BACKGROUND: Chitosan exhibits good physiochemical properties and biocompatibility, but it has poor biological activity of osseointegration. Therefore, it needs to combine with other materials for bone repair. OBJECTIVE: Calcined bone/chitosan composite was prepared and its physiochemical properties and biocompatibility were analyzed. METHODS: Calcined bone/chitosan composite was prepared at a mass ratio of 1:2, 1:1, 2:1 respectively by solution blending method. The physicochemical properties of three composite materials were characterized. Passage 5 mouse L929 fibroblasts were treated with the leaching solution of three composite materials. The cytotoxicity of three composite materials was detected by the CCK-8 test. RESULTS AND CONCLUSION: (1) X-ray diffraction and Fourier Transform Infrared Spectroscopy showed that the essential components of three composite materials were hydroxyapatite and β-tricalcium phosphate. The characteristic diffraction peaks of hydroxyapatite/β-tricalcium phosphate increased with the increase of the proportion of calcined bone. (2) Scanning electron microscopy showed that calcined bone particles were evenly dispersed in chitosan medium. (3) With the increase of the proportion of calcined bone, the compressive strength of the composite decreased gradually. (4) After 7 days of culture, the cells in the leaching solution of three composite materials grew well without obvious change in morphology. By the ninth day, the relative proliferation rate of the cells in the leaching solution of three composite materials was over 90%. Cytotoxicity was grade 1, which meets the safety standard of biomaterials. (5) These results suggest that the calcined bone/chitosan composite has good structural characteristics, physicochemical properties and suitable compressive strength and is safe and non-toxic.
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Tricalcium phosphate (TCP) is one of the most widely used bioceramics for constructing bone tissue engineering scaffold. The three-dimensional (3D) printed TCP scaffold has precise and controllable pore structure, while with the limitation of insufficient mechanical properties. In this study, we investigated the effect of sintering temperature on the mechanical properties of 3D-printed TCP scaffolds in detail, due to the important role of the sintering process on the mechanical properties of bioceramic scaffolds. The morphology, mass and volume shrinkage, porosity, mechanical properties and degradation property of the scaffold was studied. The results showed that the scaffold sintered at 1 150℃ had the maximum volume shrinkage, the minimum porosity and optimal mechanical strength, with the compressive strength of (6.52 ± 0.84) MPa and the compressive modulus of (100.08 ± 18.6) MPa, which could meet the requirements of human cancellous bone. In addition, the 1 150℃ sintered scaffold degraded most slowly in the acidic environment compared to the scaffolds sintered at the other temperatures, demonstrating its optimal mechanical stability over long-term implantation. The scaffold can support bone mesenchymal stem cells (BMSCs) adherence and rapid proliferation and has good biocompatibility. In summary, this paper optimizes the sintering process of 3D printed TCP scaffold and improves its mechanical properties, which lays a foundation for its application as a load-bearing bone.
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PURPOSE: To overcome several drawbacks of chemically-crosslinked collagen membranes, modification processes such as ultraviolet (UV) crosslinking and the addition of biphasic calcium phosphate (BCP) to collagen membranes have been introduced. This study evaluated the efficacy and biocompatibility of BCP-supplemented UV-crosslinked collagen membrane for guided bone regeneration (GBR) in a rabbit calvarial model.METHODS: Four circular bone defects (diameter, 8 mm) were created in the calvarium of 10 rabbits. Each defect was randomly allocated to one of the following groups: 1) the sham control group (spontaneous healing); 2) the M group (defect coverage with a BCP-supplemented UV-crosslinked collagen membrane and no graft material); 3) the BG (defects filled with BCP particles without membrane coverage); and 4) the BG+M group (defects filled with BCP particles and covered with a BCP-supplemented UV-crosslinked collagen membrane in a conventional GBR procedure). At 2 and 8 weeks, rabbits were sacrificed, and experimental defects were investigated histologically and by micro-computed tomography (micro-CT).RESULTS: In both micro-CT and histometric analyses, the BG and BG+M groups at both 2 and 8 weeks showed significantly higher new bone formation than the control group. On micro-CT, the new bone volume of the BG+M group (48.39±5.47 mm3) was larger than that of the BG group (38.71±2.24 mm3, P=0.032) at 8 weeks. Histologically, greater new bone area was observed in the BG+M group than in the BG or M groups. BCP-supplemented UV-crosslinked collagen membrane did not cause an abnormal cellular reaction and was stable until 8 weeks.CONCLUSIONS: Enhanced new bone formation in GBR can be achieved by simultaneously using bone graft material and a BCP-supplemented UV-crosslinked collagen membrane, which showed high biocompatibility and resistance to degradation, making it a biocompatible alternative to chemically-crosslinked collagen membranes.
Subject(s)
Animals , Rabbits , Absorbable Implants , Bone Regeneration , Calcium , Collagen , Membranes , Osteogenesis , Skull , Transplants , Ultraviolet RaysABSTRACT
@#Introduction: This study aims to investigate different residue sizes of β-tricalcium phosphate (β-TCP) micro-granules as carriers to assess antibacterial activity and drug-control release behavior of ampicillin (AMP-) and antimycotic (AMC-). Incorporation of antibiotic into the β-TCP micro-granules and it sustain release behavior could be used as alternative solution to reduce the risk of osteomyelitis and bone infections risks. Methods: Three different residue sizes (less than 300 µm, 300 µm and 600 µm) were prepared and coated with antibiotics solution (20 µg/µl of ampicillin and 100X antimycotic solution) by using two methods; dip and stream coating. After 72 h, 1.5 mL of distilled water was added to the treated (β-TCP) micro-granules at two different pH value (5.0 and 7.4). The extracted solution was further analyzed by Kirby Bauer disc diffusion test and spectrophotometer assay. Results: The solution containing AMC-(β-TCP) micro-granules with the size of 300 µm residue produced the largest inhibition zones against Escherichia coli (E. coli). All residue sizes coated with AMP- showed no antibacterial activity against both strains; Staphylococcus aureus (S. aureus) and E.coli. Additionally, the release behavior of AMC-(β-TCP) micro-granules was found not depending on the pH, but on the size of residue. Complete drug release was rapidly observed within 48 h. Conclusion: Based on this findings, it showed AMC-(β-TCP) micro-granules had an antibacterial activity against Gram-negative strain. Specifically, it can reduced the growth rate of E. coli and the rapid release behavior of AMC(β-TCP) micro-granules help in minimizing the risk-infections in early stage of implantation.