Laparoscopic radical cystectomy and orthotopic ileal neobladder used for treatment of invasive bladder cancer / 中国内镜杂志

Objective To investigate the surgical methods and experience of laparoscopic radical cystectomy and orthotopic ileal neobladder for invasive bladder cancer. Methods The clinical data of 14 patients with invasive bladder cancer underwent laparoscopic radical cystectomy and orthotopic ileal neobladder were collected retrospectively during March 2011 and October 2014. Results The 13 patients with invasive bladder cancer were successfully completed laparoscopic radical cystectomy and orthotopic ileal neobladder. 1 case was treated with laparotomy because of unsatisfactory surgery ifeld caused by excessive tumor bleeding. Twelve cases of the urethra-neobaldder anastomosis were completed through the abdominal incision, while for the other 2 cases, the anastomosis was done under the laparoscope, 2 cases were performed neovesicourethral anastomosis using single-needle running sutures through laparoscopy. The median operative time was 444 minutes, the mean intraoperative blood loss was 490 ml. Postoperative pathologic results conifrmed that 12 cases were bladder transitional cell carcinoma (1 case with partial squamous cell carcinoma) and 2 cases with bladder adenocarcinoma. No severe complication occurred except for 2 cases of urinary leakage and 1 case of urinary incontinence. Patients were followed up for 6-56 months,within which 3 patients were died of distant metastasis, 1 case was detected with intracranial metastasis, 1 case was found with urethra-vesical anastomotic stenosis while cured after urethrotomy. Ten cases were well recovered and the mean volume of the neobladder was 300 ml. Conclusions Laparoscopic radical cystectomy and orthotopic ileal neobladder have the advantage of better therapeutic effects, safety, minimal invasion and rapid recovery, which are the preferred therapeutic methods for invasive bladder cancer.

Effects of maleic anhydride-modified poly(D,L-lactic acid) on the adhesion, proliferation and differentiation of osteoblasts / 生物医学工程学杂志

The main objective of this study was to observe the adhesion, proliferation and differentiation of mouse osteblast-like MC3T3-E1 cells cultured on maleic anhydride-modified poly(D,L-lactic acid) (MPLA) and poly(D,L-lactic acid) (PDLLA) polymers, and to evaluate the cytocompatibility of MPLA polymer. The effects of MPLA and PDLLA polymers on the morphology, adhesion, proliferation, the content of total cellular protein, alkaline phosphatase (ALP) activity and the content of Ca of MC3T3-E1 cells were explored. These results indicated that MC3T3-E1 cells on MPLA polymer adhered and spread more fully. On MPLA polymer, the proliferation, total protein content, ALP activity, Ca content of the cells were significantly higher than those of the cells on PDLLA polymer (P < 0.01). It was concluded that MPLA polymer could promote the adhesion, spreading, proliferation and the synthesis of protein of osteoblasts, and also induced the differentiation and mineralization of osteoblasts, suggesting that MPLA polymer might have the better cytocompatibility than PDLLA.

Effects of stretching-shape recovering process on the cytocompatibility of novel shape memory polyurethane for bone repair / 中国组织工程研究

BACKGROUND: Shape memory polyurethane (SMPU) may be employed for bone repair capable of resisting stress shielding and bone non-union due to the shape memory effect responding to changed external temperature. Evaluating the cytocompatibility of SMPU is important for its further in vivo experiments and applications. However, few have been done to investigate the cytocompatibility of SMPU after encounted from deforming and shape recovering.OBJECTIVE: To evaluate the osteoblast compatibility of SMPU before and after stretching-shape recovering process. METHODS: Solvent casting method was used to fabricate SMPU films; the obtained SMPU films were stretched to 200%, and then fixed and finally recovered to its odginal shape at T_g+15 ℃, T_g-15 ℃ and T_g+15 ℃, respectively. Atomic force microscope (AFM) with tapping mode was employed to probe the surface morphology and phase separation of SMPU. Primary osteoblasts at 3-5 passages were seeded on SMPU films in vitro to evaluate the adhesion, proliferation and spreading of osteoblasts. RESULTS AND CONCLUSION: There were obvious and regular phase separation resulted from soft segments and hard segments in SMPU, and some groove-ddge architectures within a scale of micrometers were produced by the stretching-shape recovering process. These special micropatterned structures promoted osteoblast adhesion and proliferation, and also resulted in partially oriented cell growth along the grooves. Shape memory process, i.e. stretching-shape recovering process may obviously change the surface morphology of SMPU films, and suggesting better biocompatibility with osteoblasts.

Effect of mechano growth factor on radial fracture healing in rabbits / 中国组织工程研究

BACKGROUND: Current research of mechano growth factor (MGF) mainly focuses on the muscles and nerve damage and repair, and it has bean confirmed that MGF can promote muscle cell hypertrophy and nerve repair significantly. Regarding its role in fracture healing is unclear. OBJECTIVE: To investigate the effect of MGF on radial fracture healing in rabbits. METHODS: By using random digital table method, 12 New Zealand rabbits were divided into 3 groups: blank control group, low-dose MGF group and high-dose MGF group. The models with 5 mm bone defect were produced in the middle of the left radius in rabbits. At 3 days after the surgical operation, the defective areas were given 0.2 mL PBS or 0.2 mL MGF (0.36 and 0.72 g/L) injected into the ends of fracture areas, respectively, once per day for continuous 5 days. At 4, 6, 8 weeks after operation, X-ray photography was used to evaluate the healing of fracture, and the histological examinations were performed at the 8~(th) weak to observe the call morphology at the fracture lesion. RESULTS AND CONCLUSION: At 1 day after operation, the activities of rabbits were reduced, with slightly reduced food intake, at 2 days they almost recovered to normal activities and diet. At 3 days, the surgical incision slightly swelled with a small amount of bleeding and without obvious signs of infection. All 12 rabbits entered the final analysis. X-rays showed that two fracture ends have basically combined in the high-dose MGF group at 4 weeks post-surgery, cortical bone was continuous and fracture lines were unclear. At 6 weaks the bone medullary cavity almost run through and fully run through at 8 weeks. The healing time in the high-dose MGF group was remarkably shorter than that in blank control group and low-dose MGF group, the healing was in high quality. At 8 weeks after operation, a large number of osteoid tissues were observed in the blank control group, a small amount of woven bone formed, at a transition period from the fibrous bone callus to the bony bone callus; a large number of woven bone formed inthe low-dose MGF group, at bony bone callus period; in the high-dose MGF group, a large number of woven bones converted into mature lamellar bone, at the callus rebuilding phase, which was consistent with imaging results. It is indicated that MGF can accelerate fracture healing significantly in a rabbit model and shows a dose-dependent manner in a certain range.

Expression of mechano-growth factor in osteoblasts under mechanical stretch / 中华创伤杂志

Objective To analyze the protein expression and subcellular distribution of mechanogrowth factor (MGF) in ostcoblasts under stretch stimulation. Methods Cyclic stretching was applied to osteohlasts by a mechanical stretching device. The whole-cell proteins were extracted from controlled and stretched osteoblasts for detecting the protcin expression level of MGF by Western blot and observing the intracellular distribution of MGF by fluorescent immunocytological method. Results Western blot showed significant increase of expression of MGF in osteoblasts under stimulation of cyclic stretching. The level of protein was increased by four folds after 12-hour stretching of osteohlasts, and then declined sharply. Immunofluorescence analysis showed that MGF was mainly distributed in the nuclei of osteoblasts. ConcinsionsUnder the cyclic stimulation, the expression of MGF reaches a short period of peak in osteoblasts, which may be related to the injury of osteoblasts caused by stretching. MGF is mainly distributed in the nuclei of osteoblasts, indicating that MGF may contain nuclear localization signal and modulate the expression of relative genes.

The study of apoptosis and mechanism of cells exposed to steep pulse / 生物医学工程学杂志

This experiment was designed to study the apoptosis and related mechanism of adherent liver tumor cells (SMMC-7721) and adherent normal liver cells (HL-7702) when they were exposed to the steep pulse generated by the steep pulse apparatus for tumor treatment. The results showed that the steep pulse of 200 V could induce tumor cells apoptosis. The tumor cells presented with their apoptosis when they were exposed to the steep pulse from 200 V to 250 V. Laser scanning confocal microscopy was used to make a real time study of calcium burst when the adherent tumor cells were exposed to the steep pulse. The results showed:On the condition of no extracellular Ca2+, the concentration of Ca2+ in tumor cells exposed to the steep pulse of 150 V did not change; the concentration of Ca2+ in tumor cells exposed to the steep pulse of 200 V decreased; the concentration of Ca2+ in tumor cells exposed to the steep pulse of 250 V decreased more evidently. On the condition of existing extracellular Ca2+, the concentration of Ca2+ in tumor cells exposed to the steep pulse of 150 V did not change; the concentration of Ca2+ in tumor cells exposed to the steep pulse of 200 V decreased little; the concentration of Ca2+ in tumor cells exposed to the steep pulse of 250 V reduced little, too. Maybe the change of calcium burst in the tumor cells is the mechanism of apoptosis when cells are exposed to the steep pulse.

The physiological response of osteoblasts to pulsatile fluid flow shear stress in vitro / 生物医学工程学杂志

This is an experimental study in the realm of physiology inquiring about the effect of pulsatile fluid flow shear stress on the proliferation, differentiation and functions of osteoblasts;the objective is to validate the important effect of fluid flow shear stress on the mechanics adaptability of bone tissue. The osteoblasts derived from Wistar rat's calvaria were exposed to fluid shear stress 5, 10, 20 and 30 mN/cm2 for 3, 6, 9, 12, 24, 36h respectively in the flow chamber. The ability of proliferation, alkaline phosphatase (ALP) activity and extracellular calcium secretion of osteoblasts were assessed. The results showed that fluid flow shear stress at 5, and 10 mN/cm2 increased the proliferation, but at 20 and 30 N/cm2, the shear stress inhibited the proliferation. The shear stress at 5, 10, 20 mN/cm2 increased the ALP activity and extracellular calcium secretion of osteoblasts, and advanced the time of the peak value of ALP activity during the experiment period, but the shear stress at 30 mN/cm2 decreased ALP activity. So osteoblasts responded rapidly to shear stress; the proliferation, differentiation and mineralization of cells were regulated in the presence of some shear stress; and such regulation exhibited a pattern of dependence on the mN/cm2 level of shear stress.

Expression of mechano-growth factor in Escherichia coli and activity analysis / 生物工程学报

Mechano-growth factor (MGF) is one of IGF-1 isoforms. MGF is mechanosensitive and has important functions in muscle hypertrophy, regeneration and nerve injury recovery. In this study, MGF cDNA (330 bp) was cloned from stretched osteoblasts by RT-PCR. In order to avoid prolin residue inhibiting enterokinase cleavage, 9bp of MGF cDNA 5' end sequence was truncated by primer, then the obtained truncated MGF (des(1-3)MGF) cDNA (321 bp) was subcloned in pET32a(+) vector to construct a prokaryotic recombination expression plasmid. Trx/des(1-3)MGF fusion protein, existing in forms of solution, was expressed in transformed Escherichia coli strain BL21(DE3) by IPTG induction at 30 degres C. The supernatant of cell lysates was subjected to ion exchange chromatography and Ni2+ metal affinity chromatography, and the fusion protein was obtained with the purity over 95%. After the fusion protein was cleaved by enterokinase, Trx and des(1-3)MGF was isolated by reverse-phase HPLC. Through these procedures, des(1-3) MGF was obtained with the purity of 98%. The protein molecular mass was conformity to the theoretical value by SDS-PAGE and mass spectrometry analysis. The purified des(1-3)MGF was incubated with MC3T3-E1 for cell proliferation and migration assays. The results show that des(1-3)MGF exhibited more facilitative effects on proliferation and migration of MC3T3-E1 than that of des(1-3)IGF-1.

The relationship between intracellular actin distribution and morphology and cell adherence / 生物医学工程学杂志

It is believed that there exists some relationship between the distribution and morphology of intracellular actin and cell adherence. Cells are likely to be deteched when the quantity of actin filament decreases. Actin filaments locate in the fringe of cancer cells and cells cultured in static state, so that these filaments can stretch out and form pseudopodia to adhere to the matrix. When these cells are stimulated their pseudopodia retract so that they can easily be detached from the matrix. When external forces are exerted on cells to adhere and deadhere from the matrix, the morphology and distribution of skeleton actin will change, so as the cells' morphology. The skeleton actins in cells are changed differently to adapt to different external forces which are imposed on the cells. It is obvious that the relationship between the mechanism of cell adhering to the matrix and the morphology & distribution of actins needs more attention.

Effects of mechanical strain on the proliferation and expression of IGF-1 mRNA in rat osteoblasts / 生物医学工程学杂志

With the use of a cyclic strain unit, the proliferation and gene expression of IGF-1 in the rat osteoblasts that underwent mechanical strain were studied. The cells were subjected to 15% elongation at frequency 20 cycles/min for different loading time. Under the action of different loading time, the relative proliferation index of the rat osteoblasts was the biggest of all when loading time was 12h; during the course, the expression of IGF-1 mRNA increased significantly, and then gradually tended toward 1 with the increase of the loading time. These results demonstrate that osteoblasts respond to the mechanical forces which may regulate the activities of osteoblasts indirectly by promoting the autocrine effect of IGF-1. Loaded osteoblasts can adjust and adapt themselves to new mechanical stimulation, and hence maintain a new state of equilibrium.

Characterization and histocompatibility of acellular bone collagen matrices / 生物医学工程学杂志

A processing technique has been developed to prepare acellular bone collagen matrix (ABCM) and ABCM-PDLLA composite materials. The properties of these materials were characterized through several different methods. The histocompatibility of the materials were investigated by ELISA (enzyme linked immunosorbent assay) test and healing the defection of New Zealand white rabbit bilateral radius. The spectroscopy indicated that the major inorganic and organic components of the bone blocks were carbonated hydroxyapatite and collagen respectively,and the fatty and cellular components were. completely eliminated. The test results also revealed that the materials had good mechanical property and well-internnected pore structure, and the addition of PDLLA increased the strength of the materials. The ELISA results demonstrated that the materials had low immunogenicity in short order, and the degree of immune response caused by ABCM was greater than that by ABCM-PDLLA. All of the grafts exhibited good osteoconductive ability and a new bone form after the creeping substitution. In conclusion, two kinds of materials with good histocompatibility have been prepared, and owing to its good mechanical performance and low immunogenicity, ABCM-PDLLA is a better candidate for bone substitute and bone tissue engineering scaffold when compared with single ABCM.

Effect of overload environment on IGF-1 expression of osteoblasts / 生物医学工程学杂志

In the study of the relationship between cells overloading and the formation, regeneration and growth of bone, the text discussed osteoblasts express IGF-1 variation under overloading environment. The research of overloading on cellular level may elucidate the mechanical effect on the formation, regeneration and growth of bone and the mechanism of cell response in bone.

Molecular mechanism of bone absorption in osteoclast / 生物医学工程学杂志

The physiological reconstruction of bone is strictly dependent on bone resorption. Bone resorption is believed to be a complicated molecular reaction process that occurs in the microcircumstance of bone tissue. A lot of enzymes and factors take part in this process, yet there are not enough data with reference to the activation of osteoclast, resorption of bone matrix, regulation of bone resorption. In this paper we review the importance of matrix metalloproteinases (MMPs) in transfer of osteoclast and degradation of bone matrix, and the function of receptor activator of NF-kappaB-ligand (RANKL) and osteoprotegerin (OPG) in regulation of bone resorption.

Advance in research of osteoblast adhesion to bioactive materials / 生物医学工程学杂志

In the research field of bone tissue engineering, the interaction of osteoblast and substrate is pivotal and the adhesion of osteoblast to biomaterials is the basic condition. Firstly, osteoblast must adhere to biomaterials, then it can migrate, proliferate and differentiate. This paper introduces the proteins relating to the adhesion of osteoblast and the influences of relating surface character and modification of biomaterials on the adhesion ability of osteoblast. These could serve as basic data and useful reference for the development of bone tissue engineering and tissue engineering scaffold materials.

The mechanotransduction mechanism of how osteoblasts respond to mechanical stimulation / 生物医学工程学杂志

The stress environment regulates the factors of growth, resorption and remolding in bone tissue. Mechanical stimulation at cell physical level affects the physiological activity of osteoblasts, including proliferation, ALP activity and osteocalcin production. Mechanotransduction is a procedure which transduces the biophysical force into biochemical responses. It is also the basis of many physiological functions. The early response genes (c-fos, c-jun), the second message systems (Ca2+, NO, cAMP) and the mechano-sensitive cation channel are involved in the mechanotransduction course when osteoblasts respond to the mechanical stimulation.

Advances in apoptosis induced by biomaterials / 生物医学工程学杂志

Biomedical materials are the biomaterials that, used in physiological system for diagnosis, treatment, plerosis or replacement of tissues and organs. Apoptosis, also known as PCD or ACD, is a normal physiological mechanism of cell in organism and a process of automatic cell death in which multicell organism modulates the development of organism and maintains the stability of internal environment. The human beings are able to understand the interaction between the material and organism at the molecular level due to the widely-used biomedical material and the development of material science, life science and biological technology. The research of that interaction is mainly focused on biocompatibility, while much attention has been drawn to the apoptosis induced by biomaterial concerning that apoptosis could be caused by inducing factor, and many therapies of diseases are closely related to inducing apoptosis. Based on the recent research advances of apoptosis in life science and the development of biomaterials, the pathways of apoptosis induced by biomaterials were reviewed; from the different views, the pathways of signal transduction of apoptosis include traditional pathway of signal transduction, the pathway of death receptor, and the pathway through mitochondrion. By the other way, the pathways of apoptosis caused by reactive oxygen species induced by biomaterials and apoptosis by affecting cell adhesion to biomaterials and so forth were discussed also. It indicates that the pathways to apoptosis due to biomaterials possess the characteristics of variety, intercrossing and multiplicity. It is essential for a research to inquire into the mechanism of apoptosis that is induced by biomaterials, and further into the manufacturing of biomaterials. This review is devoted to shedding light on the wide application of biomaterials in the therapy of human diseases, especially in the therapy of cancer that is closely related to apoptosis.

Preparation and characterization of bovine bone collagen matrix / 生物医学工程学杂志

A process of preparing bovine cortical bone in order to form materials suitable for biomedical xenograft implants was described. Fresh bone samples cut from the middiaphyseal region of bovine femora were obtained from a local slaughterhouse. The bovine bone collagen matrix (BBCM) of various shapes fabricated from bovine bone by defatting and deproteination procedure may be implanted surgically for various purposes. The bone cubes were first defatted in a mixture of defatting agent; subsequently, the samples were extracted to release noncollagenous proteins, followed by digestion using a proteolytic enzyme to remove the telopeptide portions of collagen and residual noncollagenous proteins. Finally,the samples were dried in vacuum, packed and sterilized by gamma irradiation. The bone specimens were characterized by a suite of analytical techniques involving FTIR spectroscopy, X-ray diffraction spectroscopy, differential scanning calorimetry (DSC), uniaxial tension mechanical tests and scanning electron microscopy (SEM). The result showed that BBCM occurred as a white structure with suitable porosity. It contains reasonable proprotion of mineral and organic components in the original osseous architecture of the bovine bone, which is beneficial to keeping the mechanic property and weaker immunogenicity; therefore, it can serve as a potential bone implantable material and extracellular matrix material in bone tissue engineering.

Compatibility of a novel ethylenediamine modified polylactic acid with osteoblasts / 生物医学工程学杂志

Biocompatibility of a newly developed ethylenediamine modified poly (DL-latic acid) (EMPLA) with osteoblasts was investigated by means of cell morphology and cell proliferation. Films of PLA and EMPLA were made by solvent casting. Osteoblasts obtained from crania of neonatal Wistar rats were cultured on surfaces of PLA and EMPLA, with glass as control. The cell morphology was observed by phase contrast microscope and the cell proliferation was determined by MTT assay. The morphology observations revealed that the osteoblasts cultured on EMPLA spread wider than those on PLA, and much more cells were confluent on EMPLA, compared to those on PLA and glass. The growth curves showed the osteoblasts on EMPLA grew faster than did those on PLA and glass. The results exhibited that the biocompatibility of EMPLA with osteoblasts is better than that of PLA and glass, which suggested wide applications of EMPLA in biomedical area, especially in tissue engineering.

The application and advancement of rapid prototyping technology in bone tissue engineering / 生物医学工程学杂志

In bone tissue engineering, a highly porous artificial extracellular matrix or scaffold is essential to the attachment, proliferation and differentiation of bone cells (osteoblast, osteoclast and osteocytes) and the formation of bone tissue. However, conventional scaffold materials for bone tissue engineering proved less valuable for actual applications because they lack mechanical strength, interconnected channel network, and controllable porosity or channel size. Therefore,to explore the ideal scaffold materials is one of the popular studies on current bone tissue engineering. In this paper, we review, the application and advancement of a newly-developed technology generally known as rapid prototyping (RP) techniques in bone tissue engineering.

Effects of mechanical strain on the proliferation of human pulmonary epithelial cells and reorganization of integrins / 第三军医大学学报

Objective To study the effects of mechanical strain on the proliferation of the human pulmonary epithelial cell and the redistribution of its membrane receptors, integrins ? 5 and ? 1. Methods A cyclic strain unit in vitro was designed. The cellular proliferative index was measured by flow cytometry and the redistribution of ? 5 and ? 1 integrins was analyzed in human pulmonary epithelial cell line H727 by laser confocal microscopy. Results The cellular proliferative index reduced significantly after cells were subjected to 15% elongation at frequencies of 20 cycles/min or 40 cycles/min for 24 h. In human pulmonary epithelial H727 cells, ? 5 and ? 1 integrins transferred from the apical layer to the basal layer and formed an adhesion plaque after 24 h exposure to 15% elongation at frequency of 40 cycles/min. Conclusion The results suggest that ? 5 and ? 1 integrins in pulmonary epithelial cells may play an important role in the transduction of mechanical stress.