Abordaje facial global del paciente estético: protocolo Skin Age Management

Aesthetic dermatology includes many minimally invasive therapies that can help our patients age gracefully and discreetly. Because it is hard to systematize these treatments to make patients aware of the options they have for the area of the face they want to improve, at Clínica Dermatológica Internacional, we have developed the Skin Age Management (SAM) protocol. In this article, we describe the protocol, which is aimed at helping doctors and patients to better understand and plan available treatments, underlining the advisability of combining techniques with the goal of achieving discreet changes to obtain what we consider to be optimum results, based on our experience at our center.     

Bioactivity of PEEK GRF30 and Ti6Al4V SLM in Simulated Body Fluid and Hank’s Balanced Salt Solution

In recent years, scientists have defined two main paths for orthopedic implant fabrication: searching for new materials with properties closest to natural bone in order to reduce the stress-shielding effect or creating individually adapted geometry of the implant with the use and Rapid Prototyping methods. Therefore, materials such as PEEK GRF30 and Ti6Al4V selective laser melting (SLM) are of interest. They are defined as materials suitable for implants, however, the knowledge of their bioactivity, a feature which is one of the most desirable properties of biomaterials, is still insufficient. Using Simulated Body Fluid and Hank’s Balanced Salt Solution, the bioactivity of PEEK GRF30 and Ti6Al4V SLM was assessed, as well as commercial Ti6Al4V as a reference material. Ten cylindrical samples of each material were prepared and immersed in solutions per period from 2 to 28 days at 37 °C. Optical analysis of the changes on the examined surfaces suggested that right after 2-day crystals with different morphologies were formed on each material. Further analysis of the chemical composition of the altered surfaces confirmed the formation of a calcium phosphate layer on them, however, the Ca/P ratio was slightly different from 1.67. On the basis of the obtained results, it can be concluded that both PEEK GRF30 and Ti6Al4V SLM are characterized by appropriate—comparable to Ti6Al4V—bioactivity.     

Functionalization of Polycaprolactone Electrospun Osteoplastic Scaffolds with Fluorapatite and Hydroxyapatite Nanoparticles: Biocompatibility Comparison of Human Versus Mouse Mesenchymal Stem Cells

A capability for effective tissue reparation is a living requirement for all multicellular organisms. Bone exits as a precisely orchestrated balance of bioactivities of bone forming osteoblasts and bone resorbing osteoclasts. The main feature of osteoblasts is their capability to produce massive extracellular matrix enriched with calcium phosphate minerals. Hydroxyapatite and its composites represent the most common form of bone mineral providing mechanical strength and significant osteoinductive properties. Herein, hydroxyapatite and fluorapatite functionalized composite scaffolds based on electrospun polycaprolactone have been successfully fabricated. Physicochemical properties, biocompatibility and osteoinductivity of generated matrices have been validated. Both the hydroxyapatite and fluorapatite containing polycaprolactone composite scaffolds demonstrated good biocompatibility towards mesenchymal stem cells. Moreover, the presence of both hydroxyapatite and fluorapatite nanoparticles increased scaffolds’ wettability. Furthermore, incorporation of fluorapatite nanoparticles enhanced the ability of the composite scaffolds to interact and support the mesenchymal stem cells attachment to their surfaces as compared to hydroxyapatite enriched composite scaffolds. The study of osteoinductive properties showed the capacity of fluorapatite and hydroxyapatite containing composite scaffolds to potentiate the stimulation of early stages of mesenchymal stem cells’ osteoblast differentiation. Therefore, polycaprolactone based composite scaffolds functionalized with fluorapatite nanoparticles generates a promising platform for future bone tissue engineering applications.     

Polymer hydration and stiffness at biointerfaces and related cellular processes

The direct and indirect (by changing mechanical properties) effects of hydration at interfaces on cellular processes and tissue diseases are reviewed. The essential effect of substrate stiffness on cellular processes was demonstrated in the last decade. The combined effect of surface stiffness and hydration at interfaces has garnered much less attention, though hydration and dehydration play important roles in biological processes. This review focuses on the studies that demonstrate how hydration affects biological processes at interfaces. Elevated sodium and dehydration stimulate inflammatory signaling in endothelial cells and promote atherosclerosis. Various types of implant and blood contacting device coatings with varied surface stiffness and hydration have been reported. Effect of hydration on polymer modulus of elasticity and viscoelasticity was discussed taking into account cells adhesion, migration, proliferation, differentiation on surfaces with various degree of hydration. Future directions of research were considered, including the use of nanotechnology to regulate the hydration degree.     

碳纳米管-羟磷灰石复合材料研究进展

羟磷灰石有与生物骨相似的化学组成和晶体结构,作为骨种植材料备受关注。但它脆性大,力学性能欠佳,临床应用受到局限。近年来,碳纳米管因为具有高强度、高弹性模量、耐扭折等理想的机械性能,被用于羟磷灰石的加强。笔者拟对目前碳纳米管-羟磷灰石复合材料的合成方法和研究现状作一综述。     

Human enamel erosion in constant composition citric acid solutions as a function of degree of saturation with respect to hydroxyapatite

The objective of this study was to investigate human enamel erosion under constant composition conditions, as a function of solution degree of saturation (DS) with respect to hydroxyapatite. The experimental conditions were relevant to the initial stages of enamel erosion by soft drinks. Nanoindentation was used to compare enamel surface softening caused by a control mineral water and two citric acid solutions with DS = 0.000 and DS = 0.032, both having pH 3.30. Enamel hardness and reduced elastic modulus were measured after 0, 30, 60, 120, 300 and 600 s exposure. A statistically significant change in enamel hardness was detected after 30 s exposure to both citric acid solutions, indicating that nanoindentation is extremely sensitive to the initial stages of erosion. There was a statistically significant difference between the mechanical properties of enamel exposed to the two citric acid solutions after 30, 60 and 120 s. At these times, the solution with DS = 0.000 caused twice as much enamel softening as that with DS = 0.032. This demonstrates that it may be possible to design a soft drink with a low erosive potential and a good taste by a small change in DS, at a typical drink pH.     

引导组织再生术与骨移植联合治疗根分叉病变

目的:以牙周引导再生术(GTR)观察胶原膜与Bio-Oss和HA联合治疗Ⅱ～Ⅲ度根分叉病变的疗效。方法:选53例根分叉区病变的患牙65个,分HA GTR及Bio-Oss GTR二组,术后以定性及定量指标对比分析疗效。结果:与术前相比两组术后牙周袋深度(PD)、根分叉水平探入深度(HPD)、附着丧失(AL)、牙龈指数(GI)均明显减少,且有显著性差异(P<0.05);Bio-Oss GTR组PD值低于HA GTR组(P<0.05)。两组骨缺损处均有明显新生牙槽骨。结论:Bio-Oss和HA联合GTR治疗Ⅱ～Ⅲ度根分叉病变,可获得良好的临床疗效,Bio-Oss稍优于HA。     

新型纳米羟基磷灰石(n-HA)糊剂封闭根尖性能及其对病原菌抗菌活性的体外实验

目的：研究新型纳米羟基磷灰石根管充填糊剂（n-HA）、AH-Plus根管封闭剂的根尖封闭性能以及二者对感染根管优势菌牙龈卟啉单胞菌（Porphyromonas gingivalis,Pg）、具核梭杆菌（Fusobacteria nu-cleatum,Fn）、中间普氏菌（Prevotalla intermedius,Pi）生长的影响。方法：实验一34个离体单根管牙随机分为4组,用镍钛旋转器械Protaper预备根管,阳性对照（2个）、阴性对照（2个）、2个实验组（各15个）,分别用新型n-HA、AH-plus根充糊剂加牙胶尖以冷侧压法根充恰填,染料渗入法检查根尖微渗漏。实验二选用Pg、Fn、Pi作为实验菌株,常规打孔法测定新型纳米羟基磷灰石根管充填料、AH-Plus根管封闭剂的抑菌效果。结果：所有根充糊剂充填后根尖部位均有微渗漏,AH-plus组的微渗漏值低于n-HA组,2组结果间无统计学意义（P〉0.05）。n-HA与AH-Plus糊剂对Pg、Fn、Pi均有一定的抑菌作用,但n-HA的抑菌作用明显强于AH-Plus。结论：2种根充糊剂充填后都不能完全封闭根尖孔,AH-plus根充糊剂的根尖封闭性优于n-HA组。n-HA根充糊剂具有较理想的抑菌效果。     

煅石膏、骨形成蛋白及羟基磷灰石三元复合人工骨修复骨缺损的实验研究

以煅石膏(PLP）作为颗粒型羟基磷灰石(HA)人工骨粘接成形剂和骨形成蛋白(BMP)的载体，制成三元复合人工骨．分别用HA—bBMP、HA—PLP和单纯HA植入狗下颌骨实验性骨缺损中，采用组织学、定量组织学、免疫组织化学、X线摄片和扫描电镜观察的方法评价该复合人工骨的生物学性能。术后1，2，4，8和16周观察发现，HA—bBMP—PLP复合人工骨具有明显的骨诱导活性．PLP可充当BMP缓慢释放系统载体．增强BMP骨诱导活性，和作为颗粒型HA的粘接成形剂．使复合人工骨具有一定的可塑性和成形性，可达到准确的植入，植入后早期可有效防止HA颗粒移动。本研究证实．HA—bBMP—PLP三元复合人工骨不但可限制植入后HA颗粒的早期移动，更重要的是可以迅速增加新骨形成量．从形态和功能上大大提高了复合人工骨修复骨缺损的质量。