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1.
Gladius Lewis Mark R. Towler Daniel Boyd Matthew J. German Anthony W. Wren Owen M. Clarkin Andrew Yates 《Journal of materials science. Materials in medicine》2010,21(1):59-66
Vertebroplasty (VP) and balloon kyphoplasty (BKP) are now widely used for treating patients in whom the pain due to vertebral
compression fractures is severe and has proved to be refractory to conservative treatment. These procedures involve percutaneous
delivery of a bolus of an injectable bone cement either directly to the fractured vertebral body, VB (VP) or to a void created
in it by an inflatable bone tamp (BKP). Thus, the cement is a vital component of both procedures. In the vast majority of
VPs and BKPs, a poly(methyl methacrylate) (PMMA) bone cement is used. This material has many shortcomings, notably lack of
bioactivity and very limited resorbability. Thus, there is room for alternative cements. We report here on two variants of
a novel, bioactive, Al-free, Zn-based glass polyalkenoate cement (Zn-GPC), and how their properties compare to those of an
injectable PMMA bone cement (SIMPL) that is widely used in VP and BKP. The properties determined were injectability, radiopacity,
uniaxial compressive strength, and biaxial flexural modulus. In addition, we compared the compression fatigue lives of a validated
synthetic osteoporotic VB model (a polyurethane foam cube with an 8 mm-diameter through-thickness cylindrical hole), at 0–2300 N
and 3 Hz, when the hole was filled with each of the three cements. A critical review of the results suggests that the performance
of each of the Zn-GPCs is comparable to that of SIMPL; thus, the former cements merit further study with a view to being alternatives
to an injectable PMMA cement for use in VP and BKP. 相似文献
2.
Gangfeng Hu Luwei Xiao Hong Fu Dawei Bi Haitao Ma Peijian Tong 《Journal of materials science. Materials in medicine》2010,21(2):627-634
Injectable calcium sulphate/phosphate cement (CSPC) with degradable characteristic was developed by introduction of calcium
sulphate (CS) into calcium phosphate cement (CPC). The setting time, compressive strength, composition, degradation, cells
and tissue responses to the CSPC were investigated. The results show that the injectable CSPC with optimum L/P ratio exhibited
good injectability, and had suitable setting time and mechanical properties. Furthermore, the CSPC had good degradability
and its degradation significantly faster than that of CPC in Tris–HCl solution. Cell culture results indicate that CSPC was
biocompatible and could support MG63 cell attachment and proliferation. To investigate the in vivo biocompatibility and osteogenesis,
the CSPC were implanted in the bone defects of rabbits. Histological evaluation shows that the introduction of CS into CPC
enhanced the efficiency of new bone formation, and CSPC exhibited good biocompatibility, degradability and osteoconductivity
with host bone in vivo. It can be concluded that the injectable CSPC had a significant clinical advantage over CPC, and might
have potential to be applied in orthopedic, reconstructive and maxillofacial surgery, especially for minimally invasive techniques. 相似文献
3.
The objective of this study is to evaluate local response to a bioactive glass based composite putty (NovaBone Putty) in a
vertebral body defect model in sheep, as compared to NovaBone, a bioactive glass particulate. Two time periods were used for
the study, 6 and 12 weeks. Empty defects were also used as a control. In comparing the three test groups, the relative amount
of new bone for both grafted defects was substantially greater than for the empty controls (P < 0.05). At 6 weeks, the bone formation was 42% for NovaBone Putty, 27% for NovaBone and 1.2% for the ungrafted empty defect.
At 12 weeks, the bone formation was 51.4% for NovaBone Putty, 47.3% for NovaBone and 5.1% for the empty defect. NovaBone Putty,
the test material, had greater bone content than the NovaBone, both of which were significantly greater than the empty control. 相似文献
4.
S. Abiraman H. K. Varma T. V. Kumari P. R. Umashankar Annie John 《Bulletin of Materials Science》2002,25(5):419-429
This study investigates quantitatively and qualitatively the sol-gel derived bioactive glass-ceramic system (BGS)—apatite-wollastonite
(AW) type granules in the size range of 0.5–1 mm, as an effective graft material for bone augmentation and restoration. Scanning
electron micrographs (SEM) of the sintered granules revealed the rough material surface with micropores in the range 10–30
μm. X-ray diffraction (XRD) pattern of the granules revealed the presence of crystalline phases of the hydroxyapatite and
wollastonite, and the functional groups of the silicate and phosphates were identified by Fourier transform infrared spectroscopy
(FT-IR). Thein vitro cell culture studies with L929 mouse fibroblast cell line showed very few cells adhered on the BGS disc after 24 h. This
could be due to the highly reactive surface of the disc concomitant with the crystallization but not due to the cytotoxicity
of the material, since the cellular viability (MTT assay) with the material was 80‰ Cytotoxicity and cytocompatibility studies
proved that the material was non-toxic and biocompatible. After 12 weeks of implantation of the BGS granules in the tibia
bone of New Zealand white rabbits, the granules were found to be well osteointegrated, as observed in the radiographs. Angiogram
with barium sulphate and Indian ink after 12 weeks showed the presence of microcapillaries in the vicinity of the implant
site implicating high vascularity. Gross observation of the implant site did not show any inflammation or necrosis. SEM of
the implanted site after 24 weeks revealed good osteointegration of the material with the newly formed bone and host bone.
New bone was also observed within the material, which was degrading. Histological evaluation of the bone healing with the
BGS granules in the tibial defect at all time intervals was without inflammation or fibrous tissue encapsulation. After 2
weeks the new bone was observed as a trabeculae network around the granules, and by 6 weeks the defect was completely closed
with immature woven bone. By 12 weeks mature woven bone was observed, and new immature woven bone was seen within the cracks
of the granules. After 24 weeks the defect was completely healed with lamellar bone and the size of the granules decreased.
Histomorphometrically the area percentage of new bone formed was 67.77% after 12 weeks and 63.37% after 24 weeks. Less bone
formation after 24 weeks was due to an increased implant surface area contributed by the material degradation and active bone
remodeling. The osteostimulative and osteoconductive potential of the BGS granules was established by tetracycline labelling
of the mineralizing areas by 2 and 6 weeks. This sol-gel derived BGS granules proved to be bioactive and resorbable which
in turn encouraged active bone formation. 相似文献
5.
Dan Kai Dongxiao Li Xiangdong Zhu Lei Zhang Hongsong Fan Xingdong Zhang 《Journal of materials science. Materials in medicine》2009,20(8):1595-1602
An injectable calcium phosphate cement (CPC) with porous structure and excellent anti-washout ability was developed in the
study. Citric acid and sodium bicarbonate were added into the CPC powder consisting of tetracalcium phosphate (TTCP) and dicalcium
phosphate dihydrate (DCPD) to form macro-pores, then different concentrations of sodium hyaluronate (NaHA) solution, as liquid
phase, was added into the cement to investigate its effect on CPC’s performance. The prepared CPCs were tested on workability
(injectable time and setting time), mechanical strength, as well as anti-washout ability. The experimental results showed
that addition of NaHA not only enhanced the anti-washout ability of the CPC dramatically but also improve its other properties.
When NaHA concentration was 0.6 wt%, the injectable time elongated to 15.7 ± 0.6 min, the initial and final setting times
were respectively shorten to 18.3 ± 1.2 and 58.7 ± 2.1 min, and the compressive strength were increased to 18.78 ± 1.83 MPa.
On the other hand, Addition of NaHA showed little effect on porous structure of the CPC and enhanced its bioactivity obviously,
which was confirmed by the apatite formation on its surface after immersion in simulated body fluid (SBF). In conclusion,
as an in situ shaped injectable biomaterials, the CPC with appropriate addition of NaHA would notably improve its performance
and might be used in minimal invasive surgery for bone repair or reconstruction. 相似文献
6.
Hernández L Gurruchaga M Goñi I 《Journal of materials science. Materials in medicine》2009,20(1):89-97
The utilization of injectable acrylic bone cement is crucial to the outcome of vertebroplasty and kyphoplasty. However, only
a few cements that are in clinical use today are formulated specifically for use in these procedures and even these formulations
are not regarded as “ideal” injectable bone cements. The aim of this work is to prepare bioactive bone cements by adding strontium
hydroxyapatite (SrHA) to a cement formulation based on polymethylmethacrylate. Thus, the cement combines the immediate mechanical
support given by the setting of the acrylic matrix with optimum radiopacity and bioactivity due to the incorporation of the
SrHA. Formulations of bioactive cement were prepared with 10 and 20 wt% of SrHA as synthesised and after a surface treatment
with the monomer. Cements loaded with treated particles showed an enhancement of their handling properties, and hence, an
improvement on their rheological behaviour, injectabilities and compressive parameters. Further experiments were also carried
out to determine their bioactivity and biocompatibility and results appear in other publication. 相似文献
7.
Nicholas Dunne Valerie Jack Rochelle O’Hara David Farrar Fraser Buchanan 《Journal of materials science. Materials in medicine》2010,21(8):2263-2270
The strategic incorporation of bioresorbable polymeric additives to calcium-deficient hydroxyapatite cement may provide short-term
structural reinforcement and modify the modulus to closer match bone. The longer-term resorption properties may also be improved,
creating pathways for bone in-growth. The aim of this study was to investigate the resorption process of a calcium phosphate
cement system containing either in polyglycolic acid tri-methylene carbonate particles or polyglycolic acid fibres. This was
achieved by in vitro aging in physiological conditions (phosphate buffered solution at 37°C) over 12 weeks. The unreinforced
CPC exhibited an increase in compressive strength at 12 weeks, however catastrophic failure was observed above a critical
loading. The fracture behaviour of cement was improved by the incorporation of PGA fibres; the cement retained its cohesive
structure after critical loading. Gravimetric analysis and scanning electron microscopy showed a large proportion of the fibres
had resorbed after 12 weeks allowing for the increased cement porosity, which could facilitate cell infiltration and faster
integration of natural bone. Incorporating the particulate additives in the cement did not provide any mechanism for mechanical
property augmentation or did not demonstrate any appreciable level of resorption after 12 weeks. 相似文献
8.
Pengyan Qiao Juan Wang Qiufei Xie Fangfang Li Limin Dong Tao Xu 《Materials science & engineering. C, Materials for biological applications》2013,33(8):4633-4639
Osteoblasts or stem cells have been delivered into injectable calcium phosphate cement (CPC) to improve its effectiveness and biological function. However, the osteogenic potential of the new construct in vivo has been rarely reported, and there are no reports on alginate–chitosan microencapsulated osteoblasts mixed with CPC. This study aimed to develop alginate–chitosan microencapsulated mouse osteoblast MC3T3-E1 cells (AC-cells), evaluate the osteogenic potential of a calcium phosphate cement complex with these AC-cells (CPC-AC-cell), and trace the implanted MC3T3-E1 cells in vivo. MC3T3-E1 cells were embedded in alginate microcapsules, cultured in osteogenic medium for 7 days, and then covered with chitosan before mixing with a paste of β-tricalcium phosphate/calcium phosphate cement (β-TCP/CPC). The construct was injected into the dorsal subcutaneous area of nude mice. Lamellar-bone-like mineralization, newly formed collagen and angiogenesis were observed at 4 weeks. At 8 weeks, areas of newly formed collagen expanded; further absorption of β-TCP/CPC and osteoid-like structures could be seen. Cell tracing in vivo showed that implanted MC3T3-E1 cells were clearly visible at 2 weeks. These in vivo results indicate that the novel injectable CPC-AC-cell construct is promising for bone tissue engineering applications. 相似文献
9.
Cai S Zhai Y Xu G Lu S Zhou W Ye X 《Journal of materials science. Materials in medicine》2011,22(11):2487-2496
To develop high macroporous and degradable bone cements which can be used as the substitute of bone repairing and drug carriers,
cross-linked gelatin microspheres (GMs) and calcium sulfate dihydrate (CSD) powder were incorporated into calcium phosphate
bone cement (CPC) to induce macropores, adjust drug release and control setting time of α-TCP–liquid mixtures after degradation
of GMs and dissolution of CSD. In this study, CSD was introduced into CPC/10GMs composites to offset the prolonged setting
time caused by the incorporation of GMs, and gentamicin sulphate (GS) was chosen as the model drug entrapped within the GMs.
The effects of CSD amount on the cement properties, drug release ability and final macroporosity after GMs degradation were
studied in comparison with CPC/GMs cements. The resulting cements presented reduced setting time and increased compressive
strength as the content of CSD below 5 wt%. Sustained release of GS was obtained on at least 21 days, and release rates were
found to be chiefly controlled by the GMs degradation rate. After 4 weeks of degradation study, the resulting composite cements
appeared macroporous, degradable and suitable compressive strength, suggesting that they have potential as controlled local
drug delivery system and for cancellous bone applications. 相似文献
10.
Xin-Hui Xie Xiao-Wei Yu Shao-Xian Zeng Rui-Lin Du Yu-Huai Hu Zhen Yuan Er-Yi Lu Ke-Rong Dai Ting-Ting Tang 《Journal of materials science. Materials in medicine》2010,21(7):2165-2173
We conducted histologic and histomorphometric studies to evaluate the osteointegration of gradient coatings composed of bioactive
glass and nanohydroxyapatite (BG–nHA) on titanium-alloy orthopaedic implants and surrounding bone tissue in vivo. Titanium-alloy
implants with a gradient coating (gradient coating group), uncoated implants (uncoated group), and implants with a conventional
hydroxyapatite (HA) coating (HA coating group) were randomly implanted in bilateral femoral condyles of 36 male New Zealand
rabbits. The bone–implant contact at 12 and 24 weeks and the new bone volume in the notch created for observing bone ingrowth
at 4, 12, and 24 weeks were found greater in the gradient coating group than those in both the uncoated group and the HA coating
group (p < 0.05). Fluorescence micrographs showed active osteogenesis in the gradient coating group at 4 weeks after implantation.
These findings indicated that BG–nHA gradient coatings could enhance the osteointegration of orthopaedic implant. 相似文献
11.
Li DX Fan HS Zhu XD Tan YF Xiao WQ Lu J Xiao YM Chen JY Zhang XD 《Journal of materials science. Materials in medicine》2007,18(11):2225-2231
The aim of this research is to study the effect of the controlled releasing character of the salmon calcitonin (S-CT) loaded
injectable calcium phosphate cement (CPC) modified by adding organic phase, chitosan oligosaccharide (CO) and collagen polypeptide
(CP). The uniform design was used to determine the basic formulation with suitable injectable time for clinical application,
and then the changes of the physical characters, the controlled releasing character of the modified CPC along with the ratio
of the organic phase were also evaluated in vitro. The surface morphous of the modified CPC been implanted in the abdominal
cavity or soaked into the serum of rat was also observed by scanning electron microscope (SEM). The result shows that a suitable
formulation of modified CPC could be got, and the injectable time is 12 min, the compressive strength is 12 MPa, and the final
setting time is 40 min. Comparing with the CPC without organic phase, the releasing rate of S-CT would increase along with
the increase of the organic phase after 7th day. Therefore, a novel S-CT loaded bioactive injectable CPC for treating osteoporosis
induced bone defect was obtained, and the release of the containing S-CT was controlled easily through adjusting the ratio
of CO and CP. 相似文献
12.
Rongwei Tan Xufeng Niu Shaolei Gan Qingling Feng 《Journal of materials science. Materials in medicine》2009,20(6):1245-1253
Hydrogels are increasingly used in medicine due to their potential to be delivered into the body in a minimally invasive manner
and to be gelated at the site of introduction subsequently. The aim of this study was to develop a novel injectable and in situ-forming
gel composite (GC) comprised of calcium alginate hydrogel and nano-hydroxyapatite/collagen (nHAC), assess its rheological,
mechanical and in vitro degradable properties, and discuss the gelation mechanism. Injectable property test showed that the
injectability of GC was tunable. Rheological results indicated that three phases of pre-gel, sol–gel phase transformation
and post-gel could be found in the process of gelation. The compressive elastic modulus (E) and shear modulus (G) are in the range of 17.0–56.0 kPa and 24.7–55.0 kPa, respectively. During the in vitro degradation, the wet weight increased
in the first week, then declined in the following 3 weeks, but the dry weight lost continuously during whole study. Meanwhile,
the surface changed greatly after 2 weeks, but samples did not break down up to 28 days. These data indicate that GC exhibits
controllable initial setting time and final setting time, tunable injectability, which provides a possible injectable material
for bone repair and bone tissue engineering. 相似文献
13.
磷酸钙/BMP复合生物活性骨水泥水化性能及诱导成骨特性研究 总被引:2,自引:0,他引:2
采用微细α-磷酸三钙(α-TCP)粉料、辅助料与冻干牛骨形态发生蛋白(BMP)预先固相混合制备了新型磷酸钙(CPC)/BMP复合生物骨水泥.通过水化、凝固性能研究优化了配料成分、调和液和促凝剂组成;通过大鼠肌袋种植实验研究了骨水泥的异位成骨性能.结果表明:以α-TCP:CaHPO4:CaO(0.95:0.025:0.025)为固相配料,以0.25mol/LNaH2PO4/Na2HPO4混合液([P]T=0.5mol/L)作为调合液可制备性能优异的骨水泥材料,骨水泥初凝时间为6min,终凝时间为30min,固化强度达33MPa,达到临床手术的要求;α-TCP粉料粒度对骨水泥凝固性能影响显著,实验选用α-TCP粉料粒径d50为1.3μm;骨水泥在Hank’s溶液中浸泡5天抗压强度可达最大值;骨水泥块经浸泡后内部生成针状羟基磷灰石晶体的网状结构.新型CPC/BMP复合骨水泥异位成骨作用明显,4周即能快速形成板层骨结构,证明该新型复合材料具有较强的诱导成骨活性.该生物活性骨水泥复合材料可望成为一类新型组织工程骨修复材料. 相似文献
14.
Chen J Luo Y Hong L Ling Y Pang J Fang Y Wei K Gao X 《Journal of materials science. Materials in medicine》2011,22(3):547-555
A superior drug controlled release system capable of achieving efficient osteogenesis is in imperative demand because of limited
bone substitute tissue for the treatment of bone defect. In the present study, we investigated the potential of using poly(ε-caprolactone)–hydroxyapatite
(PCL–HA) composite microspheres as an injectable bone repair vehicle by controlled release of alendronate (AL), a medicine
that belongs to the bisphosphonates family. The PCL/HA–AL microspheres were prepared with solid/oil/water emulsion technique,
which included two processes: (1) AL was loaded on the hydroxyapatite nanoparticles; (2) the HA–AL complex was built in the
PCL matrix. The spherical PCL/HA–AL microspheres were characterized with its significantly improved encapsulation efficiency
of hydrophilic AL and better sustained release. Human bone mesenchymal stem cells (hMSCs) were cultured on the surface of
these microspheres and exhibited high proliferative profile. Specifically, in osteogenic medium, hMSCs on the surface of PCL/HA–AL
microspheres displayed superior osteogenic differentiation which was verified by alkaline phosphatase activity assay. In conclusion,
by presenting strong osteogenic commitment of hMSCs in vitro, the PCL/HA–AL microspheres have the potential to be used as
an injectable vehicle for local therapy of bone defect. 相似文献
15.
Zhu C Chang Q Zou D Zhang W Wang S Zhao J Yu W Zhang X Zhang Z Jiang X 《Journal of materials science. Materials in medicine》2011,22(8):1965-1973
The study aims to evaluate the effect of bone marrow stromal cells (BMSCs) expressing bone morphogenic protein-2 (BMP-2) mediated
by lentiviral (Lv) gene transduction combined with calcium phosphate cement (CPC) scaffolds for the repair of critical size
calvarial defects in rats. BMSCs derived from Fisher 344 rats were transduced with LvBMP-2 or lentivirus encoding enhanced
green fluorescent protein (LvEGFP) in vitro. Obvious osteogenic differentiation of BMSCs in the LvBMP-2 group was demonstrated
by alkaline phosphatase staining and alizarin red staining. Enzyme-linked immunosorbent assay results show that LvBMP-2 gene
expression in vitro can last for at least 8 weeks. Gene-transduced or untransduced BMSCs were seeded onto CPC scaffolds to
repair rat calvarial defects with a diameter of 5 mm. Scanning electron microscope analysis indicated that porous CPC scaffolds
facilitated initial adhesion and spreading of BMSCs onto its surface. Calvarial defects were successfully repaired with LvBMP-2-transduced
BMSCs/CPC constructs 8 weeks postoperatively. The percentage of new bone formation in the LvBMP-2 group was significantly
higher than in other control groups. Lentiviral mediated BMP-2 gene therapy together with CPC scaffolds can be used successfully
in calvarial repair and bone regeneration. 相似文献
16.
Le Nihouannen D Saffarzadeh A Aguado E Goyenvalle E Gauthier O Moreau F Pilet P Spaethe R Daculsi G Layrolle P 《Journal of materials science. Materials in medicine》2007,18(2):225-235
Calcium phosphate (Ca-P) ceramics are currently used in various types of orthopaedic and maxillofacial applications because
of their osteoconductive properties. Fibrin glue is also used in surgery due to its haemostatic, chemotactic and mitogenic
properties and also as scaffolds for cell culture and transplantation. In order to adapt to surgical sites, bioceramics are
shaped in blocks or granules and preferably in porous forms. Combining these bioceramics with fibrin glue provides a mouldable
and self-hardening composite biomaterial. The aim of this work is to study the osteogenic properties of this composite material
using two different animal models. The formation of newly formed bone (osteoinduction) and bone healing capacity (osteconduction)
have been study in the paravertebral muscles of sheep and in critical sized defects in the femoral condyle of rabbits, respectively.
The different implantations sites were filled with composite material associating Ca-P granules and fibrin glue. Ca-P granules
of 1–2 mm were composed with 60% of hydroxyapatite and 40% of beta tricalcium phosphate in weight. The fibrin glue was composed
of fibrinogen, thrombin and other biological factors. After both intramuscular or intraosseous implantations for 24 weeks
and 3, 6, 12 and 24 weeks, samples were analyzed using histology and histomorphometry and mechanical test. In all cases, the
newly formed bone was observed in close contact and around the ceramic granules. Depending on method of quantification, 6.7%
(with BSEM) or 17% (with μ CT) of bone had formed in the sheep muscles and around 40% in the critical sized bone rabbit defect
after 24 weeks. The Ca-P/fibrin material could be used for filling bone cavities in various clinical indications. 相似文献
17.
M. Jayabalan K. T. Shalumon M. K. Mitha 《Journal of materials science. Materials in medicine》2009,20(6):1379-1387
Biodegradable and injectable hydroxy terminated-poly propylene fumarate (HT-PPF) bone cement was developed. The injectable
formulation consisting HT-PPF and comonomer, n-vinyl pyrrolidone, calcium phosphate filler, free radical catalyst, accelerator and radiopaque agent sets rapidly to hard
mass with low exothermic temperature. The candidate bone cement attains mechanical strength more than the required compressive
strength of 5 MPa and compressive modulus 50 MPa. The candidate bone cement resin elicits cell adhesion and cytoplasmic spreading
of osteoblast cells. The cured bone cement does not induce intracutaneous irritation and skin sensitization. The candidate
bone cement is tissue compatible without eliciting any adverse tissue reactions. The candidate bone cement is osteoconductive
and inductive and allow osteointegration and bone remodeling. HT-PPF bone cement is candidate bone cement for minimally invasive
radiological procedures for the treatment of bone diseases and spinal compression fractures. 相似文献
18.
Masaharu Nakagawa Jyunichi Yamazoe 《Journal of materials science. Materials in medicine》2009,20(11):2295-2303
To achieve osteoconductivity, Ti–0.5Pt and Ti–6Al–4V–0.5Pt alloys were hydrothermally treated at 200°C in 10 mmol/l CaCl2 aqueous solution for 24 h (HT-treatment). We conducted histological investigations of the HT-treated materials by using Wistar
strain rats (SD rats) to evaluate the usefulness of the treatment. To measure the bone bond strength, the specimens were implanted
in the tibia of SD rats, and a pull-out test was conducted. From the early postoperative stages, direct bone contact was obtained
for the HT-treated implants. Within 1–4 weeks of implantation, the bone contact ratios and bone bond strengths of the HT-treated
implants were higher than those of the non-treated implants. The Ti–0.5Pt and Ti–6Al–4V–0.5Pt alloys with HT-treatment showed
the potential to develop a new implant with a high bone bond strength and rapid osteoconduction. 相似文献
19.
Xu Cui Cunju Zhao Yifei Gu Le Li Hui Wang Wenhai Huang Nai Zhou Deping Wang Yi Zhu Jun Xu Shihua Luo Changqing Zhang Mohamed N. Rahaman 《Journal of materials science. Materials in medicine》2014,25(3):733-745
Osteomyelitis (bone infection) is often difficult to cure. The commonly-used treatment of surgical debridement to remove the infected bone combined with prolonged systemic and local antibiotic treatment has limitations. In the present study, an injectable borate bioactive glass cement was developed as a carrier for the antibiotic vancomycin, characterized in vitro, and evaluated for its capacity to cure osteomyelitis in a rabbit tibial model. The cement (initial setting time = 5.8 ± 0.6 min; compressive strength = 25.6 ± 0.3 MPa) released vancomycin over ~25 days in phosphate-buffered saline, during which time the borate glass converted to hydroxyapatite (HA). When implanted in rabbit tibial defects infected with methicillin-resistant Staphylococcus aureus (MRSA)-induced osteomyelitis, the vancomycin-loaded cement converted to HA and supported new bone formation in the defects within 8 weeks. Osteomyelitis was cured in 87 % of the defects implanted with the vancomycin-loaded borate glass cement, compared to 71 % for the defects implanted with vancomycin-loaded calcium sulfate cement. The injectable borate bioactive glass cement developed in this study is a promising treatment for curing osteomyelitis and for regenerating bone in the defects following cure of the infection. 相似文献
20.
S. Shahid R. W. Billington R. G. Hill G. J. Pearson 《Journal of materials science. Materials in medicine》2010,21(11):2901-2905
The set of glass ionomer cement (GIC) is accelerated by application of ultrasound. Although GIC has somewhat displaced zinc
polycarboxylate cement (ZPC) in dental applications the latter is still extensively used. Like GIC, it provides direct adhesion
to tooth and can provide F release, but is more radiopaque and biocompatible than GIC. The aim of this study is to examine
the effect of ultrasound on the setting of ZPC using Fourier transform infra red spectroscopy and any interaction with SnF2 addition. ZPC with and without SnF2 addition (+/−S) at luting (L) 2:1 P/L ratio and restorative (R) 4:1 P/L ratio consistencies. Ultrasound is applied to the
cement using Piezon-Master 400, EMS, Switzerland at 60 s from start of mixing for 15 s. The ratios of absorbance peak height
at 1,400 cm−1 –COO– to that at 1,630 cm−1 –COOH were measured and compared those obtained for the cement not treated with US. These values were taken at the elapsed
time at which no further change in spectrum [ratio] was observed at room temperature [10–20 min]. The US results are taken
at 2 or 3 min. No US: R/+S (1.09), R/−S (1.2), L/+S (1.07), L/−S (1.04); US: R/+S (1.50), R/−S (1.64), L/+S (1.38), L/−S (1.05).
The results show all four ZPC formulations are very sensitive to ultrasound whether with or without SnF2. Reducing US to 10 s produces lower initial ratios but these increase up to 10 min when very high ratios (>2) are obtained.
Previous studies with restorative GICs found that 40–55 s US was needed to produce the effect found with 15 s on ZPCs. ZPC
powder is more basic than GIC glass; this may account for ZPC’s greater sensitivity to US. Ultrasound may provide a useful
adjunct to the clinical use of ZPC both as luting agent and temporary restorative. 相似文献