Morphometric and histological analysis of low-power laser influence on bone morphogenetic protein in bone defects repair

Bone morphogenetic proteins (BMPs) are secreted signaling molecules belonging to the transforming growth factor-β (TGF-β) superfamily. The objective of this study was to determine how gallium–aluminum–arsenium (GaAlAs) 650 nm laser influenced the action of BMPs on bone defects created in rat femurs. The sample consisted of 24 male albino Wistar rats. Group 1 was composed of rats with bone defects filled with bone-inducing substance, with the application of low-power laser. Group 2 contained rats with bone defects filled with a bone-inducing substance, without the application of low-power laser. Group 3 rats had bone defects not filled with a bone-inducing substance, with the application of low-power laser. Group 4 rats had bone defects and no treatment (control group). A bone defect was produced with drills. In groups 1 and 2 the defects were filled with a bone-inducing substance. The animals were treated with GaAlAs (50 mW) laser, energy density 4J/cm², for 80 ss on a 1 cm² area. Groups 2 and 4 were used as control. Bone samples were removed for histological procedures and morphometric analysis on the 7th, 14th and 21st days after surgery. Results obtained were subjected to statistical analysis. Rejection level for the null hypothesis was 0.05. Statistical differences were found in the comparison between group 1 (G1), G2, G3 and G4 [analysis of variance (ANOVA); P < 0.0134]. There was a statistically significant correlation between groups 1 and 4 (P < 0.01). The results of other correlations by Tukey’s post-hoc test were: group 1 vs group 3 (P = 0.341), group 1 vs group 2 (P = 0.862), group 2 vs group 4 (P = 0.061), group 2 vs group 3 (P = 0.744), and group 3 vs group 4 (P = 0.249). We concluded that the association of low-power laser with a bone-inducing substance produced better results than when low-power laser or BMPs were used alone.     

羟基磷灰石及其复合材料在骨修复中的作用及研究进展

骨缺损的治疗仍是骨科面临的一大挑战，有许多不同的材料可用来修补骨缺损。羟基磷灰石作为充填材料为新骨的形成提供支架，发挥骨传导作用而修复骨缺损，并在一定程度上具有骨诱导性能。研究具有诱导成骨和传导成骨活性的羟基磷灰石复合材料是目前研究的一大热门课题。本从临床应用的角度，评述了近几年羟基磷灰石及其复合材料特性的研究进展。     

Comparative study of porous hydroxyapatite and tricalcium phosphate as bone substitute

This study was performed to quantitate the bone ingrowth and biodegradability of porous calcium phosphate. Two kinds of coralline hydroxyapatite (CHA), along with sintered tricalcium phosphate (TCP), were evaluated. All implants had totally interconnecting pores. These pores measured 260-600 mu for CHA-Goniopora (CHAG), 190-230 microns for CHA-Porites (CHAP), and 100-300 microns for TCP. Cylindrical implants (3 mm in diameter by 8 mm in length) were implanted into the diaphyses of rabbit tibias for 3 to 24 weeks. The quantity of regenerated bone, remaining implant, nonmineralized space, and the middle two quarters of the cortical area were measured by a computerized operator-assisted analysis for bone histomorphometry. At 3 weeks after implantation, 17.3% of CHAG, 11.3% of CHAP, and 7.0% of TCP were infiltrated by regenerated bone. At 24 weeks, 56.1% of CHAG, 52.7% of CHAP, and 44.7% of TCP were occupied by lamellar-type bone. Implant degradation was noted to be 46.4% for TCP and 27.5% for CHAP. In contrast, CHAG did not show appreciable degradation until 24 weeks.     

Infrared laser light further improves bone healing when associated with bone morphogenetic proteins and guided bone regeneration: an in vivo study in a rodent model

OBJECTIVE: This study assessed histologically the effect of laser photobiomodulation on the repair of surgical defects created in the femurs of Wistar rats treated or not treated with bone morphogenetic proteins (BMPs) and organic bovine bone graft. BACKGROUND DATA: This paper is part of an ongoing series of works in which biomaterials and/or guided bone regeneration (GBR) are used in association with laser photobiomodulation. Several previous reports from our group have shown that the use of laser photobiomodulation improves the treatment of bone defects. MATERIALS AND METHODS: Forty-eight adult male Wistar rats were divided into four randomized groups: group 1 (controls, n = 12); group 2 (laser photobiomodulation, n = 12); group 3 (BMPs + organic bovine bone graft + GBR, n = 12); and group 4 (BMPs + organic bovine bone graft + GBR + laser photobiomodulation, n = 12). The irradiated groups received seven irradiations every 48 h, the first immediately after the surgical procedure. Laser photobiomodulation (830 nm, 40 mW, CW, phi approximately 0.6 mm) consisted of a total of 16 J/cm2 per session at four points (4 J/cm2 each) equally spaced around the periphery of the defect. The animals were sacrificed after 15, 21, and 30 d, and the specimens were routinely embedded in wax and stained with hematoxylin and eosin and Sirius red stains and analyzed under light microscopy. RESULTS: The results showed histological evidence of increased deposition of collagen fibers (at 15 and 21 d), as well as an increased amount of well-organized bone trabeculi at the end of the experimental period (30 d) in irradiated animals compared to non-irradiated controls. CONCLUSION: We concluded that the use of laser photobiomodulation in association with BMPs, organic bovine bone grafts, and GBR increases the positive biomodulating effects of laser energy.     

Infection following the use of porous hydroxyapatite ceramic as a bone defect filler in articular fractures

Summary This article is a preliminary report focussed on infection after implantation of porous hydroxyapatite (Endobon®) as a bone defect filler. Eighteen adults received Endobon® implants for cancellous bone defects after trauma, tumoral excision or for arthrodesis. Four patients exhibited osteoarthritis. Infections required debridementand removal of osteosynthesis material and implants. Relevant infectious organisms were Staphylococcus and Enterobacteria. The incidence of postoperative infection, the nature of the organisms and indications are discussed. Further investigations are required in order to understand the causes of infection and undertake their prophylaxis.     

Comparative histological analysis of bone healing of standardized bone defects performed with the Er:YAG laser and steel burs

This study compares the bone repair process after ostectomies performed either with the erbium:yttrium-aluminum-garnet (Er:YAG) laser or with the low-speed bur drilling. Eighteen rats were used for this study. In the control group, the ostectomy was performed with a low-speed bur drilling. In the experimental group, the ostectomy was made with an Er:YAG laser (500 mJ, 10 Hz). At 7 and 14 days after surgery, the experimental group presented earlier bone repair in comparison to the control group. The experimental group presented an altered layer of approximately 24-microm thickness, whereas the control group did not present any altered layer in the margins of the ostectomies. At 21 days, the histological features of the two groups were very similar, although the altered layer could still be seen. The Er:YAG laser successfully promoted the ablation of the bone tissue, but caused some thermal damage at the margins of the ostectomies.     

引导骨再生技术对血管化组织工程骨修复兔股骨缺损过程中骨形态发生蛋白-2成骨及表达的影响

目的 探讨引导骨再生(GBR)技术对血管化组织工程骨修复兔股骨缺损过程中局部骨形态发生蛋白-2(BMP-2)的成骨量及表达的影响,以明确GBR技术在血管化组织工程骨应用中的作用. 方法 将兔自体骨髓基质干细胞经诱导后与β-磷酸三钙材料复合,植入制备的兔股骨缺损处并在材料侧槽中植入股动静脉束,其中实验组9例,血管化组织工程骨用可吸收性GBR屏障膜包裹;对照组9例,单纯植入血管化组织工程骨,分别于术后4、8、12周通过形态学检测新生骨量,ELISA法检测骨缺损局部BMP-2的表达量. 结果 随着时间进展各组成骨量逐渐增加(实验组4、8、12周时新生骨的相对面积比分别为7.31%±0.55%,35.23%±3.07%,76.09%±3.71%,对照组4、8、12周时新生骨的相对面积比分别为17.26%±1.17%,54.50%±4.26%,82.57%±4.11%,差异均有统计学意义(P<0.05);且同一时间点实验组成骨量低于对照组,差异有统计学意义(P<0.05);术后4、8、12周时实验组骨缺损局部BMP-2 OD值分别为0.334±0.012,0.245±0.008,0.172±0.009,对照组骨缺损局部BMP-2 OD值分别为0.389±0.008,0.289±0.008,0.189±0.009;术后4周时两组骨缺损内BMP-2表达量均达峰值,此后即开始出现不同程度的下降;术后4、8、12周时骨缺损局部BMP-2表达量实验组均低于对照组,差异均有统计学意义(P<0.05). 结论 GBR屏障膜会降低血管化组织工程骨修复兔股骨缺损局部的成骨量,并减少骨缺损过程中局部BMP-2的表达量.     

仿生矿化后的丝素电纺复合支架体内成骨性能的实验研究

目的:探讨仿生矿化后的丝素电纺复合支架体内修复颅骨缺损的能力。方法:利用静电纺丝技术制备丝素电纺支架(非矿化组),通过模拟体液(SBF)浸泡法对支架仿生矿化(矿化组),扫描电镜观察其微观形貌。18只8周龄的雄性SD大鼠购自南京医科大学动物实验中心,采用随机数字表示法分为3组,分别为矿化组、非矿化组和对照组,每组6只。构...     

块状羟基磷灰石人工骨隆鼻的实验研究及临床应用

将一种低密度、具有可塑性的块状羟基磷灰石人工骨作为新型隆鼻材料,在18只新西兰白种兔的隆鼻实验中证明具有良好的生物相容性,外形稳定不变,用于临床13例也取得了满意的效果。     

块状羟基磷灰石人工骨隆鼻的实验研究及临床应用

将一种低密度、具有可塑性的块状羟基磷灰石人工骨作为新型隆鼻材料，在１８只新西兰白种兔的隆鼻实验中证明具有良好的生物相容性，外形稳定不变，用于临床１３例也取得了满意的效果。     

Effect of low-level laser therapy on bone repair: histological study in rats

BACKGROUND AND OBJECTIVES: Bone remodeling is characterized as a cyclic and lengthy process. It is currently accepted that not only this dynamics is triggered by a biological process, but also biochemical, electrical, and mechanical stimuli are key factors for the maintenance of bone tissue. The hypothesis that low-level laser therapy (LLLT) may favor bone repair has been suggested. The purpose of this study was to evaluate the bone repair in defects created in rat lower jaws after stimulation with infrared LLLT directly on the injured tissue. STUDY DESIGN/MATERIALS AND METHODS: Bone defects were prepared on the mandibles of 30 Holtzman rats allocated in two groups (n = 15), which were divided in three evaluation period (15, 45, and 60 days), with five animals each. control group-no treatment of the defect; laser group-single laser irradiation with a GaAlAs semiconductor diode laser device (lambda = 780 nm; P = 35 mW; t = 40 s; Theta = 1.0 mm; D = 178 J/cm(2); E = 1.4 J) directly on the defect area. The rats were sacrificed at the pre-established periods and the mandibles were removed and processed for staining with hematoxylin and eosin, Masson's Trichrome and picrosirius techniques. RESULTS: The histological results showed bone formation in both groups. However, the laser group exhibited an advanced tissue response compared to the control group, abbreviating the initial inflammatory reaction and promoting rapid new bone matrix formation at 15 and 45 days (P<0.05). On the other hand, there were no significant differences between the groups at 60 days. CONCLUSION: The use of infrared LLLT directly to the injured tissue showed a biostimulating effect on bone remodeling by stimulating the modulation of the initial inflammatory response and anticipating the resolution to normal conditions at the earlier periods. However, there were no differences between the groups at 60 days.     

骨髓源干细胞促进进展性肾小球硬化模型肾小球的修复再生

目的 研究骨髓源干细胞（BMDSC）移植对进展性肾小球硬化模型大鼠的作用,同时观察移植的BMDSC能否分化为肾脏内皮细胞和促进肾小球毛细血管修复再生。 方法 把携带增强型绿色荧光蛋白（EGFP）转基因SD大鼠的BMDSC移植于EGFP-SD大鼠制成嵌合性大鼠。注射抗Thy-1.1抗体,30 min后再予切除右侧肾脏制成进展性肾小球硬化模型。按是否给予BMDSC治疗分为非治疗组及治疗组,每组10只,实验期限12周。在不同时间点,检测肾功能,并进行光镜、免疫荧光病理检查。观察移植后大鼠情况,以及移植的BMDSC是否分化为肾脏内皮细胞和促进肾小球毛细血管修复再生。 结果 12周时,非治疗组大鼠仅有3只存活,余7只分别死于抗体注射后第2、7、9、11周;治疗组大鼠9只存活,仅1只死于第10周。与非治疗组比较,治疗组肾功能明显改善[BUN（43.55±29.06）比（76.58±66.19） mmol/L,Scr （138.79±75.14）比（233.38±164.43） μmol/L]。第3、7、14、28天时两组24 h尿蛋白量差异无统计学意义,而在第42、56、84天时,治疗组显著低于非治疗组。非治疗组可见严重系膜细胞和基质增生及肾小球硬化,而治疗组上述增生与硬化明显减轻;非治疗组肾小球硬化指数和系膜细胞增生指数显著高于治疗组,差异有统计学意义。治疗组肾小球可见多个BMDSC,细胞数显著多于非治疗组和正常嵌合鼠。用鼠内皮细胞标记抗体RECA-1进行双重免疫荧光染色显示,治疗组有更多BMDSC参与了肾小球内皮细胞的修复及再生,并且显著促进了肾小球毛细血管的修复再生。 结论 BMDSC静脉输入对进展性肾小球硬化有治疗作用,BMDSC可分化成内皮细胞,并可促进肾小球毛细血管的修复再生。     

Role of mesenchymal stem cells in bone regeneration and fracture repair: a review

Mesenchymal stem cells (MSCs) are non-haematopoietic stromal stem cells that have many sources, such as bone marrow, periosteum, vessel walls, adipose, muscle, tendon, peripheral circulation, umbilical cord blood, skin and dental tissues. They are capable of self-replication and of differentiating into, and contributing to the regeneration of, mesenchymal tissues, such as bone, cartilage, ligament, tendon, muscle and adipose tissue. The homing of MSCs may play an important role in the repair of bone fractures. As a composite material, the formation and growth of bone tissue is a complex process, including molecular, cell and biochemical metabolic changes. The recruitment of factors with an adequate number of MSCs and the micro-environment around the fracture are effective for fracture repair. Several studies have investigated the functional expression of various chemokine receptors, trophic factors and adhesion molecules in human MSCs. Many external factors affect MSC homing. MSCs have been used as seed cells in building tissue-engineered bone grafts. Scaffolds seeded with MSCs are most often used in tissue engineering and include biotic and abiotic materials. This knowledge provides a platform for the development of novel therapies for bone regeneration with endogenous MSCs.     

比较带蒂筋膜瓣包裹接种自体红骨髓的组织工程骨修复骨缺损时促血管化成骨与膜诱导成骨作用

目的比较带蒂筋膜瓣包裹组织工程骨在修复骨缺损时促血管化成骨与膜诱导成骨的作用,为临床修复骨缺损提供参考依据。方法采用兔自体红骨髓(autologous red bone marrow,ARBM)及含重组人BMP-2的骨诱导活性材料构建组织工程骨。将4～5月龄新西兰大白兔60只(体重2.0～2.5 kg),随机分为A、B、C 3组,A组16只,B、C组各22只。制备长1.5 cm的右尺骨长段骨-骨膜完全缺损模型,A组于骨缺损处植入组织工程骨;B、C组在骨缺损邻近处制备一筋膜瓣包裹组织工程骨后植入骨缺损,B组将筋膜瓣蒂部切断形成游离筋膜瓣,C组为带蒂筋膜瓣。术后4、8、12、16周,每组随机取4只实验动物,取骨缺损区组织进行大体观察、组织学及免疫组织化学染色观察;8、12、16周B、C组各另取2只实验动物行腋动脉墨汁灌注观察。结果大体观察示,术后4、8周A组有纤维结缔组织形成,B、C组筋膜瓣形成类似骨膜样纤维组织,其中B组有软骨样组织形成,C组有新生骨形成;12、16周A组骨痂形成少,B组新生骨较多,C组骨干形成。组织学观察示,术后4、8周A、B组新生血管和骨小梁极少,C组血管丰富且成熟骨小梁及软骨组织形成;12、16周A组新生血管及骨小梁仍较少,B组血管数量较多且成熟骨小梁显著增加,髓腔结构形成但闭阻;C组血管数量减少,成熟骨结构形成,骨髓腔再通。免疫组织化学染色示,C组各时间点CD105、CD34、Ⅷ因子表达均高于A、B组。骨形态计量分析显示,术后各时间点C组新生骨小梁体积明显大于A、B组(P<0.05);A、B组间除4周差异无统计学意义(P>0.05)外,其余时间点差异均有统计学意义(P<0.05)。血管图像分析显示术后各时间点C组骨修复区内血管再生面积比值明显大于A、B组(P<0.05)。墨汁灌注检查示,各时间点B组成骨区为稀疏的墨染区;C组成骨区墨染数量多且较密集,8周达高峰,之后逐渐减少。结论 带蒂筋膜瓣包裹复合自体ARBM的组织工程骨,早期以促血管化成骨作用占主导地位,后期血管化成骨作用逐渐消失,以膜诱导成骨作用为主。     

组织工程方法修复羊腭裂骨缺损的实验研究

目的 观察应用自体骨髓基质干细胞(BMSCs)复合珊瑚修复山羊全长腭裂骨缺损的效果.方法 体外成骨诱导山羊BMSCs复合珊瑚修复山羊全长腭裂骨缺损,以单纯珊瑚植入缺损作为对照组.于术后2、12、24、32周行头颅CT扫描并三维重建,术后24、32周行大体取材、苦味酸-品红染色和Micro-CT骨密度分析.结果 成骨诱导BMSCs在珊瑚支架生长良好.三维CT显示早期实验组骨痂较多,对照组可见珊瑚明显降解,术后24、32周腭裂骨缺损被修复,修复比例分别达(88.52±10.95)％、(90.52 ±8.12)％,组织学显示实验组有大量成熟骨,骨基质和胶原形成良好,对照组缺损不能愈合(P＜0.05),Micro-CT显示新生骨密度(759.48± 96.45 )mg HA/cm3、( 823.93±112.07) mg HA/cm3,接近正常骨(P＞0.05).结论 山羊BMSCs成骨诱导后与珊瑚复合能修复完全性腭裂骨缺损,组织工程技术可用于修复腭裂骨缺损.     

Bone repletion in vitro: evidence for a locally regulated bone repair response to PTH treatment

Normally bone formation and resorption are balanced by coupling, but in some conditions such as dietary Ca deficiency, bone resorption exceeds formation, resulting in bone loss (termed bone depletion in previous animal studies). When conditions causing depletion return to normal, a compensatory decrease in resorption and increase in formation occurs, leading to replacement of the lost bone. To test if this recovery process, termed bone repletion, might be locally regulatedupling we determined whether cellular and metabolic changes associated with repletion in vivo would as in co occur in vitro in neonatal mouse calvaria.

To increase resorption and decrease formation, serumfree cultures were treated with parathyroid hormone (10 nM bovine PTH_1–84). Although formation was inhibited ([³H]proline incorporation into [³H]hydroxyproline), the number of bone cells increased during PTH treatment. To simulate repletion, PTH was removed after 3–9 days. Within 6 days of removal of PTH, resorption (osteoclast numbers and ⁴⁵Ca release) decreased to control levels and bone formation increased to exceed untreated control levels. Autoradiographs of [³H]proline incorporation suggested an increase in the number of active bone forming cells (compared to untreated controls) after removal of PTH. These cellular and metabolic changes were similar to changes which occur during depletion and repletion in vivo. The results support the hypothesis that reversal of the resorptive processes initiated by PTH in organ cultures can occur in the absence of circulating factors. The apparent increase in the components of bone formation that were observed after PTH withdrawal may have resulted from generation of increased numbers of osteoblastic cells during PTH treatment.     

Effect of soft laser and bioactive glass on bone regeneration in the treatment of infra-bony defects (a clinical study)

This study aimed to investigate the influence of low-power 830 nm gallium–aluminium–arsenide (GaAlAs) laser [continuous wave (CW) 40 mW and fluence 4 J/cm², with total energy density of 16 J/cm²] on the healing of human infra-bony defects treated with bioactive glass graft material. Twenty patients with chronic periodontitis and bilateral infra-bony defects were included. Using a split mouth design, we treated 20 defects with bioactive glass plus laser irradiation during surgical procedures and on days 3, 5, 7 postoperatively; 20 contra-lateral defects were treated with bioactive glass only. Clinical probing pocket depths, clinical attachment levels and standardized periapical radiographs were recorded at baseline and at 3 months and 6 months postoperatively. At 3 months there was a statistically significant difference between the laser and non-laser sites in the parameters investigated. However, at 6 months, no difference was observed. Our results have confirmed the positive effect of soft laser in accelerating periodontal wound healing.     

Different effects of mechanical vibration on bone ingrowth into porous hydroxyapatite and fracture healing in a rabbit model

The effects of mechanical vibration on bone ingrowth into porous hydroxyapatite implants and fracture healing were examined radiographically, histomorphometrically, and biomechanically in a rabbit model. Fifty-three female NZW rabbits were used in this study. These rabbits were divided into four separate studies to assess the effects of 20 and 60 min of vibration/day in both implant and osteotomy models as compared with the respective non-vibrated controls. For the implant model, coral hydroxyapatite goniopora rods were implanted bilaterally into tibiae and for the osteotomy model, bilateral fibulae were osteotomized. A resonant frequency of 25 Hz mechanical vibration was used. After periods of 2, 3, 4, and 6 weeks of vibration, the rabbits were killed and examined. For the implant model, there was no significant difference between control, 20, or 60 min of vibration/day with respect to the rate or amount of new bone ingrowth. For the fracture model, 60 min of vibration/day produced a significantly larger callus as compared with the non-vibrated controls (p less than 0.05), whereas 20 min of vibration/day did not. Although biomechanical testing demonstrated a general trend for increased strength in the vibrated animals, it failed to reach significance. These results suggest that the mechanical vibration used in the present study had a beneficial effect on callus volume, possibly due to the stimulation of secondary bone healing processes, but does not appear to promote bone ingrowth into a porous hydroxyapatite implant.     

Bombyx mori derived scaffolds and their use in cartilage regeneration: a systematic review

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