[The pathogenic gene screening in a cardiomyopathy pedigree of Yunnan province].

OBJECTIVE: In this study, the sreening of candidate pathogenic gene is done among family members of an dilated cardiomyopathy(DCM)and hypertrophic cardiomyopathy (HCM) coexistence, and find the relationship between the genotype and the phenotype. METHODS: The inheritance atlas was drawn, analysis of genetic characteristics and clinical phenotype.Peripheral venous blood samples of proband and family members were candidated gene exon high-throughput sequencing sub target capture, make the result compares with related database, ultimately screening the target area of the exon and mutations of candidate genes and then using bidirectional sequencing of Sanger to sequence other family members and the health group which were matching with gender and age to testify whether there is the above mutations. RESULTS: In this family, the proband and his father carry three missense mutations, about TTNc.604 A>G(p.Lys202Glu)、TAZ c. 580A>G(p.Ile194Val)and MYH7c.730 T>C(p.Phe244Leu). The heart function of proband was failure, and accompanied malignant arrhythmia.But his father has no obvious clinical symptoms.In this family, the same genetic mutation of disease causing gene lead to different clinical phenotype, but different genetic mutation of disease causing gene lead to the same clinical phenotype.None of the mutations found in this family was found in the health group. CONCLUSION: The patient of this family carries the genetic mutation of MYH7, TTN and TAZ.The patient of this family carries the composite mutation of MYH7(+) /TTN(+) heterozygous missense mutation and TAZ(+) /TTN(+) heterozygous missense mutation may be show the performance of the genetic characteristics of early onset, severe phenotype.

Elevated expression of CX3C chemokine receptor 1 mediates recruitment of T cells into bone marrow of patients with acquired aplastic anaemia.

OBJECTIVE: Acquired aplastic anaemia (AA) is a T-cell-mediated, organ-specific autoimmune disease characterized by haematopoietic stem cell destruction in the bone marrow. The exact molecular mechanism of T-cell trafficking into the bone marrow is unclear in AA. Very late activation antigen-4 (VLA-4) and CX3C chemokine receptor 1 (CX3CR1) play active roles in many autoimmune diseases. Therefore, we investigated whether VLA-4 and CX3CR1 also contribute to T-cell migration into the bone marrow in acquired AA. DESIGN, SETTING AND SUBJECTS: Expression levels of CX3CR1 and VLA-4 and their ligands [fractalkine (CX3CL1) and vascular cell adhesion molecule-1 (VCAM-1)] were examined in 63 patients with AA and 21 healthy control subjects. T-cell chemotaxis and adhesion were analysed in 17 patients with severe AA. We also prospectively evaluated the expression pattern of CX3CR1 during treatment with antithymocyte globulin plus cyclosporine in 11 patients with severe AA. RESULTS: The proportion of peripheral and bone marrow CD4(+) and CD8(+) T cells expressing CX3CR1 and the level of CX3CL1 was increased in patients with AA. However, there was no significant difference in VLA-4 expression or VCAM-1 levels. Functional studies demonstrated that chemotaxis towards autologous bone marrow plasma or soluble CX3CL1 was significantly higher in T cells from AA patients and could be blocked by CX3CR1 inhibitors. CX3CR1-mediated T-cell adhesion was also upregulated in these patients. The expression of CX3CR1 was associated with the efficacy of immunosuppressive therapy. CONCLUSION: The present findings demonstrate that CX3CR1 plays a pivotal role in recruitment of T cells into the bone marrow in acquired AA and is a potential therapeutic target for treatment of this disorder.

Circ-0079593 promotes proliferation and migration of melanoma cells by sponging microRNA-433 and elevating EGFR expression.

OBJECTIVE: The aim of this study was to analyze the biological effects of circ-0079593 and its potential mechanism in the progression of melanoma. PATIENTS AND METHODS: Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) was carried out to detect circ-0079593 expression in melanoma tissue samples and cell lines, and the relationship between circ-0079593 expression and prognosis of patients with melanoma was analyzed based on collected clinical information. Then, the melanoma cell line stably overexpressing circ-0079593 was constructed using lentiviral stable transfection technique, and then, Cell Counting Kit-8 (CCK-8) and transwell assays were carried out to detect the proliferation rate, migration, as well as invasion abilities of melanoma cells, respectively. In addition, the potential binding targets of circ-0079593 were searched through bioinformatics analysis, and the results were verified by Dual-Luciferase assay. RESULTS: It was found that, in comparison with the normal control group, circ-0079593 showed a significantly high expression in melanoma tissues and cell lines, which predicted a poor prognosis of melanoma patients. In vitro experiments showed that the overexpression of circ-0079593 remarkably enhanced proliferation rate, as well as invasion ability of melanoma cells. Moreover, bioinformatics data analysis revealed that there exist binding sites of microRNA-433 both in circ-0079593 and EGFR. Meanwhile, the results of the Luciferase assay confirmed that circ-0079593 probably bound to microRNA-433, as an endogenous competitive RNA (ceRNA), to regulate EGFR expression. At last, cell reverse experiments demonstrated that the overexpression of microRNA-433 could attenuate the capacity of melanoma cells to proliferate and migrate, while simultaneous overexpression of circ-0079593 partially restored those cell functions. CONCLUSIONS: In melanoma, circ-0079593 may serve as a cancer-promoting gene to accelerate the rates of cell proliferation and migration, which may exert its effects by elevating EGFR expression by binding to microRNA-433.

Mechanistic understanding of compression-compression fatigue behavior of functionally graded Ti-6Al-4V mesh structure fabricated by electron beam melting.

In recent years, mesh structures have attracted significant interest for structural and functional applications. However, the mechanical strength and energy absorption ability of uniform mesh structured materials degrade with density. To address this challenge, we propose the concept of functionally graded mesh structures. The objective of the proposed research is to fundamentally understand the compressive behavior of graded mesh structures. The compression-compression fatigue behavior of functionally graded Ti-6Al-4V mesh structure under identical bulk stress condition is studied here. During cyclic deformation, it was observed that the local stress distribution in the struts was not uniform because of inhomogeneous mechanical properties of the constituents. Fatigue cracks first initiated in the lowest strength constituent, and then propagated until structural failure occurred. However, no obvious damage was observed in other constituents during the entire process. In contrast with iso-strain state, the fatigue life of graded structure is mainly determined by the constituent with the lowest strength.

Upregulation of miR-504-3p is associated with favorable prognosis of acute myeloid leukemia and may serve as a tumor suppressor by targeting MTHFD2.

OBJECTIVE: Deregulated expression of miRNAs contributes to the development of acute myeloid leukemia (AML). miR-504-3p, one of these miRNAs, has been found have upregulated expression in various human malignancies. Our present study aimed to detect the expression of miR-504-3p and its biological effect in AML. PATIENTS AND METHODS: Real-time quantitative PCR was applied to evaluate the expression level of miR-504-3p in AML cell lines and the serum from AML cases. The correlations between miR-504-3p and AML patients' clinicopathological characteristics, as well as AML patients' overall survival, were statistically assessed. Moreover, we investigated the effect of miR-504-3p knockdown on AML cells by CCK-8, Transwell assays and flow cytometry, in vitro. The Western blot, RT-PCR and luciferase reporter assay were performed to evaluate the relationship between miR-504-3p and its downstream target genes. Finally, the biological function of MTHFD2 was also analyzed. RESULTS: The expression levels of miR-504-3p were significantly down-regulated in the serum of AML patients and cell lines, and its low expression was positively associated with advanced clinical stages and poor prognosis of AML patients. Functional assays indicated that overexpression of miR-504-3p leads to AML cell growth arrest, invasion and migration inhibition, and elevated rates of apoptosis. We also found that miR-504-3p regulated the expression of MTHFD2 by binding to its 3'-UTR, and knockdown of MTHFD2 significantly suppressed AML cells proliferation, migration and invasion, and promoted apoptosis. CONCLUSIONS: Our findings provide important evidence that supports the role of miR-504-3p as a tumor suppressor in AML via the inhibition of MTHFD2 expression.

Author Correction: Sculpting nanoparticle dynamics for single-bacteria-level screening and direct binding-efficiency measurement.

The original version of this Article omitted the author Kuan Wang, who is from the 'College of Biomedical Engineering, Taipei Medical University, Taipei 11031, Taiwan' and 'Nanyang Environment & Water Research Institute, Nanyang Technological University, Singapore 637141, Singapore.'Also, the author S.H. Lim was incorrectly given as L.S. Hoi and A. Larsson was incorrectly given as A. Larson.The "Author contributions" was amended to reflect the authorship changes. It previously read 'Y.Z.S., C.-W.Q., and A.Q.L. jointly conceived the idea. Y.Z.S., S.X., Y.Z., J.B.Z., W.S., J.H.W., T.N.C., Z.C.Y., Y.L.H., B.L., P.H.Y., D.P.T., and C.-W.Q. performed the numerical simulations and theoretical analysis. Y.Z.S., S.X., and L.K.C. did the fabrication and experiments of particle hopping, biomolecule binding and flow cytometry. A.L. and L.S.H. did the SPR experiments. S.X., Y.Z.S., Y.Z., C.-W.Q., Y.-Y.C., L.K.C., T.H.Z., and A.Q.L. prepared the manuscript. S.X., Y.Z., C.-W.Q., and A.Q.L. supervised and coordinated all the work. All authors commented on the manuscript.' The correct version states 'B.L., K. W., P.H.Y.' instead of 'B.L., P.H.Y.' and 'S.H.L.' in place of 'L.S.H.'This has been corrected in both the PDF and HTML versions of the Article.

Fatigue properties of a metastable beta-type titanium alloy with reversible phase transformation.

Due to recent concern about allergic and toxic effects of Ni ions released from TiNi alloy into human body, much attention has been focused on the development of new Ni-free, metastable beta-type biomedical titanium alloys with a reversible phase transformation between the beta phase and the alpha'' martensite. This study investigates the effect of the stress-induced alpha'' martensite on the mechanical and fatigue properties of Ti-24Nb-4Zr-7.6Sn (wt.%) alloy. The results show that the as-forged alloy has a low dynamic Young's modulus of 55GPa and a recoverable tensile strain of approximately 3%. Compared with Ti-6Al-4V ELI, the studied alloy has quite a high low-cycle fatigue strength because of the effective suppression of microplastic deformation by the reversible martensitic transformation. Due to the low critical stress required to induce the martensitic transformation, it has low fatigue endurance comparable to that of Ti-6Al-4V ELI. Cold rolling produces a beta+alpha'' two-phase microstructure that is characterized by regions of nano-size beta grains interspersed with coarse grains containing alpha'' martensite plates. Cold rolling increases fatigue endurance by approximately 50% while decreasing the Young's modulus to 49GPa along the rolling direction but increasing it to 68GPa along the transverse direction. Due to the effective suppression of the brittle isothermal omega phase, balanced properties of high strength, low Young's modulus and good ductility can be achieved through ageing treatment at intermediate temperature.

[The state-of-the-art development in research on oral mucositis induced by chemotherapy].

Chemotherapy is one of the effective methods to treat cancer. However, the chemotherapy agents may cause a series of adverse reactions due to the nonselective characteristics that affect not only tumor cells, but also normal cells. Oral mucositis induced by chemotherapy is a common oral complication caused by chemotherapy in clinic. It brings great suffering to the patients and also interferes with the procedure of chemotherapy. Because of its high incidence in patients receiving chemotherapy and the significant influence, there are more researches on oral mucositis induced by chemotherapy which let us have further understanding of it. This review article will introduce the pathogenesis, risk factors, clinical manifestations, assessments, treatment and prevention of oral mucositis induced by chemotherapy.

Surface nanotopography-induced favorable modulation of bioactivity and osteoconductive potential of anodized 3D printed Ti-6Al-4V alloy mesh structure.

The objective of the study described here is to fundamentally elucidate the biological response of 3D printed Ti-6Al-4V alloy mesh structures that were surface modified to introduce titania nanotubes with an average pore size of ∼80 nm via an electrochemical anodization process from the perspective of enhancing bioactivity. The bioactivity of the mesh structures were analyzed through immersion test in simulated body fluid, which confirmed the nucleation and growth of fine globular nanoscale apatite on the nanoporous titania-modified (anodized) mesh structure surface, and agglomerated apatite with fine flakes of apatite crystals on as-fabricated mesh structure surface, that were rich in calcium and phosphorous. The cellular activity of bioactive anodized mesh structure was explored in terms of cell-material interactions involving adhesion, proliferation, synthesis of extracellular and intracellular proteins, differentiation, and mineralization. Cells adhered with a sheet-like morphology on as-fabricated mesh structure, whereas, on anodized mesh structure, numerous filopodia-like cellular extensions interacting with nanotube pores were observed. The formation of a bioactive nanoscale apatite, cell-nanotube interactions as imaged via electron microscopy, higher expression of proteins (actin, vinculin, fibronectin, and alkaline phosphatase (ALP)), and calcium content points toward the determining role of anodized mesh structure in modulating osteoblasts functions. The unique combination of nanoporous bioactive titania and interconnected porous architecture of anodized titanium alloy mesh structure provided a multimodal roughness surface ranging from nano to micro to macroscale, which helps in attaining strong primary and secondary fixation of the implant device along with the pathway for supply of nutrients and oxygen to cells and tissue.

[Clinicopathological analysis of 98 cases of benign lymphoidenosis of oral mucosa].

Objective: To investigate the clinical manifestations and pathological changes of benign lymphoadenosis of oral mucosa. Methods: The clinical data of 98 cases of benign lymphoadenosis of oral mucosa were analyzed. Results: The clinical manifestations of benign lymphoadenosis of oral mucosa included erosive ulcer (64%) and nodule (9%) and the rate of misdiagnosis was 98%. Neutrophil infiltration occurred in the epithelium of 51% cases and the lymphocyte was diffusely infiltrated in lamina propria of 83% cases. Conclusions: When the mucous membrane of the lamina propria is characterized by complex cell components, diffuse infiltrating lymphocytes and infiltration of neutrophils in mucosal epithelium without erosion and ulceration, it is necessary to highly suspect benign lymphoadenosis of oral mucosa. Finding the focal aggregation of lymphoid follicles or lymphocytes is helpful for the correct diagnosis.

Sculpting nanoparticle dynamics for single-bacteria-level screening and direct binding-efficiency measurement.

Particle trapping and binding in optical potential wells provide a versatile platform for various biomedical applications. However, implementation systems to study multi-particle contact interactions in an optical lattice remain rare. By configuring an optofluidic lattice, we demonstrate the precise control of particle interactions and functions such as controlling aggregation and multi-hopping. The mean residence time of a single particle is found considerably reduced from 7 s, as predicted by Kramer's theory, to 0.6 s, owing to the mechanical interactions among aggregated particles. The optofluidic lattice also enables single-bacteria-level screening of biological binding agents such as antibodies through particle-enabled bacteria hopping. The binding efficiency of antibodies could be determined directly, selectively, quantitatively and efficiently. This work enriches the fundamental mechanisms of particle kinetics and offers new possibilities for probing and utilising unprecedented biomolecule interactions at single-bacteria level.

Elastic deformation behaviour of Ti-24Nb-4Zr-7.9Sn for biomedical applications.

In this paper, the elastic deformation behaviour of a recently developed beta-type titanium alloy Ti-24Nb-4Zr-7.9Sn (wt.%) that consists of non-toxic elements and is intended for biomedical applications is described. Tensile tests show that this alloy in the as hot-rolled state exhibits peculiar non-linear elastic behaviour with maximum recoverable strain up to 3.3% and incipient Young's modulus of 42GPa. Solution treatment at high temperature has trivial effect on super-elasticity but decreases strength and slightly increases the incipient Young's modulus. Ageing treatment in the (alpha+beta) two-phase field increases both strength and Young's modulus and results in a combination of high strength and relatively low elastic modulus. In spite of the formation of the alpha phase, short time ageing has no effect on super-elasticity, whereas the non-linear elastic behaviour transforms gradually to normal linear elasticity with the increase of ageing time. We suggest sluggish, partially reversible processes of stress-induced phase transformation and/or incipient kink bands as the origin of the above peculiar elastic behaviour.

Osteoblast cellular activity on low elastic modulus Ti-24Nb-4Zr-8Sn alloy.

OBJECTIVES: Low modulus ß-titanium alloys with non-toxic alloying elements are envisaged to provide good biocompatibility and alleviate the undesired stress shielding effect. The objective of this study is to fundamentally elucidate the biological response of novel high strength-low elastic modulus Ti2448 alloy through the study of bioactivity and osteoblast cell functions. METHODS: Characterization techniques such as SEM, EDX, XRD, and fluorescence microscopy were utilized to analyze the microstructure, morphology, chemical composition, and cell adhesion. The cellular activity was explored in terms of cell-to-cell communication involving proliferation, spreading, synthesis of extracellular and intracellular proteins, differentiation, and mineralization. RESULTS: The formation of fine apatite-like crystals on the surface during immersion test in simulated body fluid confirmed the bioactivity of the surface, which provided the favorable osteogenic microenvironment for cell-material interaction. The proliferation and differentiation of pre-osteoblasts and their ability to form a well mineralized bone-like extracellular matrix (ECM) by secreting bone markers (ALP, calcium, etc.) over the surface point toward the determining role of unique surface chemistry and surface properties of the Ti-24Nb-4Zr-8Sn (Ti2448) alloy in modulating osteoblasts functions. SIGNIFICANCE: These results demonstrated that the low modulus (∼49GPa) Ti2448 alloy with non-toxic alloying elements can be used as a potential dental or orthopedic load-bearing implant material.

Cellular response of osteoblasts to low modulus Ti-24Nb-4Zr-8Sn alloy mesh structure.

Titanium alloys (Ti-6Al-4V and Ti-6Al-7Nb) are widely used for implants, which are characterized by high elastic modulus (∼110 GPa) with (α + ß) structure and that may induce undesirable stress shielding effect and immune responses associated with the presence of toxic elements. In this regard, we have combined the attributes of a new alloy design and the concept of additive manufacturing to fabricate 3D scaffolds with an interconnected porous structure. The new alloy is a ß-type Ti-24Nb-4Zr-8Sn (Ti2448) alloy with significantly reduced modulus. In the present study, we explore the biological response of electron beam melted low modulus Ti2448 alloy porous mesh structure through the elucidation of bioactivity and osteoblast functions. The cellular activity was explored in terms of cell-to-cell communication involving proliferation, spreading, synthesis of extracellular and intracellular proteins, differentiation, and mineralization. The formation of fine apatite-like crystals on the surface during immersion test in simulated body fluid confirmed the bioactivity of the scaffold surface, which provided the favorable osteogenic microenvironment for cell-material interaction. The combination of unique surface chemistry and interconnected porous architecture provided the desired pathway for supply of nutrients and oxygen to cells and a favorable osteogenic micro-environment for incorporation (on-growth and in-growth) of osteoblasts. The proliferation and differentiation of pre-osteoblasts and their ability to form a well mineralized bone-like extracellular matrix (ECM) by secreting bone markers (ALP, calcium, etc.) over the struts of the scaffold point toward the determining role of unique surface chemistry and 3D architecture of the Ti2448 alloy mesh structure in modulating osteoblasts functions. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 859-870, 2017.

Functional response of osteoblasts in functionally gradient titanium alloy mesh arrays processed by 3D additive manufacturing.

We elucidate here the osteoblasts functions and cellular activity in 3D printed interconnected porous architecture of functionally gradient Ti-6Al-4V alloy mesh structures in terms of cell proliferation and growth, distribution of cell nuclei, synthesis of proteins (actin, vinculin, and fibronectin), and calcium deposition. Cell culture studies with pre-osteoblasts indicated that the interconnected porous architecture of functionally gradient mesh arrays was conducive to osteoblast functions. However, there were statistically significant differences in the cellular response depending on the pore size in the functionally gradient structure. The interconnected porous architecture contributed to the distribution of cells from the large pore size (G1) to the small pore size (G3), with consequent synthesis of extracellular matrix and calcium precipitation. The gradient mesh structure significantly impacted cell adhesion and influenced the proliferation stage, such that there was high distribution of cells on struts of the gradient mesh structure. Actin and vinculin showed a significant difference in normalized expression level of protein per cell, which was absent in the case of fibronectin. Osteoblasts present on mesh struts formed a confluent sheet, bridging the pores through numerous cytoplasmic extensions. The gradient mesh structure fabricated by electron beam melting was explored to obtain fundamental insights on cellular activity with respect to osteoblast functions.

High-resolution and multi-range particle separation by microscopic vibration in an optofluidic chip.

An optofluidic chip is demonstrated in experiments for high-resolution and multi-range particle separation through the optically-induced microscopic vibration effect, where nanoparticles are trapped in loosely overdamped optical potential wells created with combined optical and fluidic constraints. It is the first demonstration of separating single nanoparticles with diameters ranging from 60 to 100 nm with a resolution of 10 nm. Nanoparticles vibrate with an amplitude of 3-7 µm in the loosely overdamped potential wells in the microchannel. The proposed optofluidic device is capable of high-resolution particle separation at both nanoscale and microscale without reconfiguring the device. The separation of bacteria from other larger cells is accomplished using the same chip and operation conditions. The unique trapping mechanism and the superb performance in high-resolution and multi-range particle separation of the proposed optofluidic chip promise great potential for a diverse range of biomedical applications.

The functional response of bioactive titania-modified three-dimensional Ti-6Al-4V mesh structure toward providing a favorable pathway for intercellular communication and osteoincorporation.

The objective of the study is to fundamentally elucidate the biological response of 3D printed mesh structures subjected to plasma electrolytic oxidation process through the study of osteoblast functions. The cellular activity of plasma electrolytic-oxidized mesh structure was explored in terms of cell-to-cell communication involving proliferation, synthesis of extracellular and intracellular proteins, and mineralization. Upon plasma electrolytic oxidation of the mesh structure, a thin layer of bioactive titania with pore size 1-3 µm was nucleated on the surface. The combination of microporous bioactive titania and interconnected porous architecture provided the desired pathway for supply of nutrients and oxygen to cells and tissue and a favorable osteogenic microenvironment for tissue on-growth and in-growth, in relation to the unmodified mesh structure. The formation of a confluent layer as envisaged via electron microscopy and quantitative assessment of the expression level of proteins (actin, vinculin, and fibronectin) point toward the determining role of surface-modified mesh structure in modulating osteoblasts functions. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2488-2501, 2016.

The influence of cell morphology on the compressive fatigue behavior of Ti-6Al-4V meshes fabricated by electron beam melting.

Additive manufacturing technique is a promising approach for fabricating cellular bone substitutes such as trabecular and cortical bones because of the ability to adjust process parameters to fabricate different shapes and inner structures. Considering the long term safe application in human body, the metallic cellular implants are expected to exhibit superior fatigue property. The objective of the study was to study the influence of cell shape on the compressive fatigue behavior of Ti-6Al-4V mesh arrays fabricated by electron beam melting. The results indicated that the underlying fatigue mechanism for the three kinds of meshes (cubic, G7 and rhombic dodecahedron) is the interaction of cyclic ratcheting and fatigue crack growth on the struts, which is closely related to cumulative effect of buckling and bending deformation of the strut. By increasing the buckling deformation on the struts through cell shape design, the cyclic ratcheting rate of the meshes during cyclic deformation was decreased and accordingly, the compressive fatigue strength was increased. With increasing bending deformation of struts, fatigue crack growth in struts contributed more to the fatigue damage of meshes. Rough surface and pores contained in the struts significantly deteriorated the compressive fatigue strength of the struts. By optimizing the buckling and bending deformation through cell shape design, Ti-6Al-4V alloy cellular solids with high fatigue strength and low modulus can be fabricated by the EBM technique.

Osteoblast functions in functionally graded Ti-6Al-4 V mesh structures.

We describe here the combined efforts of engineering and biological sciences as a systemic approach to fundamentally elucidate osteoblast functions in functionally graded Ti-6Al-4 V mesh structures in relation to uniform/monolithic mesh arrays. First, the interconnecting porous architecture of functionally graded mesh arrays was conducive to cellular functions including attachment, proliferation, and mineralization. The underlying reason is that the graded fabricated structure with cells seeded from the large pore size side provided a channel for efficient transfer of nutrients to other end of the structure (small pore size), leading to the generation of mineralized extracellular matrix by differentiating pre-osteoblasts. Second, a comparative and parametric study indicated that gradient mesh structure had a pronounced effect on cell adhesion and mineralization, and strongly influenced the proliferation phase. High intensity and near-uniform distribution of proteins (actin and vinculin) on struts of the gradient mesh structure (cells seeded from large pore side) implied signal transduction during cell adhesion and was responsible for superior cellular activity, in comparison to the uniform mesh structure and non-porous titanium alloy. Cells adhered to the mesh struts by forming a sheet, bridging the pores through numerous cytoplasmic extensions, in the case of porous mesh structures. Intercellular interaction in porous structures provided a pathway for cells to communicate and mature to a differentiated phenotype. Furthermore, the capability of cells to migrate through the interconnecting porous architecture on mesh structures led to colonization of the entire structure. Cells were embedded layer-by-layer in the extracellular matrix as the matrix mineralized. The outcomes of the study are expected to address challenges associated with the treatment of segmental bone defects and bone-remodeling through favorable modulation of cellular response. Moreover, the study provides a foundation for a new branch of functionally graded materials with interconnected porous architecture.

Preparation, characterization and nasal delivery of alpha-cobrotoxin-loaded poly(lactide-co-glycolide)/polyanhydride microspheres.

In this study, alpha-cobrotoxin was incorporated into the microspheres composed of poly(lactide-co-glycolide) (PLGA) and poly[1,3-bis(p-carboxy-phenoxy) propane-co-p-(carboxyethylformamido) benzoic anhydride] (P(CPP:CEFB)) and intranasally delivered to model rats in order to improve its analgesic activity. The microspheres with high entrapment efficiency (>80%) and average diameter of about 25 microm could be prepared by a modified water-in-oil-in-oil (w/o/o) emulsion solvent evaporation method. Scanning electron micrograph (SEM) study indicated that P(CPP:CEFB) content played a considerable role on the morphology and degradation of the microspheres. The presence of P(CPP:CEFB) in the microspheres increased their residence time at the surface of the nasal rat mucosa. The toxicity of the composite microspheres to nasal mucosa was proved to be mild and reversible. A tail flick assay was used to evaluate the antinociceptive activity of the microspheres after nasal administration. Compared with the free alpha-cobrotoxin and PLGA microspheres, PLGA/P(CPP:CEFB) microspheres showed an apparent increase in the strength and duration of the antinociceptive effect at the same dose of alpha-cobrotoxin (80 microg/kg body weight).