Bio-Medical Materials and Engineering - Volume 21, issue 5-6

Authors: Biemond, J. Elizabeth | Hannink, G. | Verdonschot, N. | Buma, P.

Article Type: Research Article

Abstract: Electron beam melting (E-beam) is a new technology to produce 3-dimensional surface topographies for cementless orthopedic implants. The effect of two newly designed highly porous E-beam engineered surface structures (cubic and star) on attachment, proliferation and differentiation of human mesenchymal stem cells (hMSCs) was investigated and compared to a solid sandblasted control. SEM analysis showed that the E-beam structures allowed cells to attach and spread. Proliferation on the new surface structures was comparable to the solid control. Furthermore, differentiation on the 3D structures was comparable to the control specimen. When culturing 300,000 cells for 10 days, the cubic structure showed …a significantly higher differentiation rate compared to the sandblasted specimen. We conclude that the results for attachment, proliferation and differentiation of mesenchymal stem cells on the newly engineered 3-dimensional E-beam surface topographies are promising. In vivo experiments are necessary to assess the bone ingrowth potential of the new surface structures. Show more

Keywords: Electron beam melting, surface characteristics, proliferation, differentiation

DOI: 10.3233/BME-2012-0675

Citation: Bio-Medical Materials and Engineering, vol. 21, no. 5-6, pp. 271-279, 2011

Authors: Kohn, Mark D. | Sun, Yu-long | Zhao, Chunfeng | Thoreson, Andrew R. | Jay, Gregory D. | An, Kai-Nan | Amadio, Peter C.

Article Type: Research Article

Abstract: The lubricating ability of human synoviocyte lubricin and bovine lubricin purified from synovial fluid was investigated and compared using a canine in vitro tendon model. Our null hypothesis was that these two forms of lubricin would have equal lubricating ability. Forty two canine hind-limbs were used. The peroneus longus (PL) tendons were harvested, along with the proximal phalanx and flexor digitorum profundus of the second or fifth digit with its proximal fibro-osseous pulley. Forty PL tendons were randomly assigned to one of four treatment groups. After gliding resistance testing, two intact PL tendons and two tendons in each group were …randomly selected for surface observation with scanning electron microscopy (SEM). The variance of the PL saline group mean gliding resistance was significantly different from other groups. There was a significant treatment-cycle interaction effect on the mean gliding resistance. On SEM, the surface of the saline treated PL tendons appeared rough, whereas the other tendon surfaces appeared smooth. Human synoviocyte lubricin functioned as well as bovine synovial fluid lubricin to reduce friction of canine PL tendons in vitro. This data suggest that treatment using the two forms of lubricin are mechanically similar. Show more

Keywords: Human bovine lubricin, gliding resistance, flexor tendon

DOI: 10.3233/BME-2012-0676

Citation: Bio-Medical Materials and Engineering, vol. 21, no. 5-6, pp. 281-289, 2011

Authors: Yagami, Kimitoshi | Shirota, Tatsuo | Shintani, Satoru | Mayahara, Mitsuori | Nishizawa, Mikio | Yanagisawa, Shigeru | Sammons, Rachel | Kuboki, Yoshinori

Article Type: Research Article

Abstract: To establish an effective method for bone augmentation, we introduced a new honeycomb-like β-tricalcium phosphate (H-β-TCP) with BMP-2 as a scaffold, whose unique geometrical properties induce osteoblastic differentiation of autologous bone marrow mesenchymal stem cells (BMSCs). A total of six beagle dogs from 6 to 7 years old were used for this study. BMSCs were cultured with autologous serum and BMP-2 on H-β-TCP. Differentiation to osteoblasts was demonstrated in vitro and exo vivo. Scanning electron microscopy revealed formation and calcification of a matrix-like structure within the H-β-TCP tunnels in BMSC culture. Moreover, treatment of BMP-2 promoted osteoblastic differentiation of …BMSCs in H-β-TCP in a diffusion chamber. These results indicated that H-β-TCP may be a useful tool for construction of functional artificial bone. Show more

Keywords: Honeycomb-form β-TCP, osteoblastic differentiation, bone marrow mesenchymal stem cells

DOI: 10.3233/BME-2012-0677

Citation: Bio-Medical Materials and Engineering, vol. 21, no. 5-6, pp. 291-306, 2011

Authors: Radetzki, F. | Wohlrab, D. | Zeh, A. | Delank, K.S. | Mendel, T. | Berger, G. | Syrowatka, F. | Mayr, O. | Bernstein, A.

Article Type: Research Article

Abstract: Resorbable ceramics can promote the bony integration of implants. Their rate of degradation should ideally be synchronized with bone regeneration. This study examined the effect of rapidly resorbable calcium phosphate ceramics 602020, GB14, 305020 on adherence, proliferation and morphology of human bone-derived cells (HBDC) in comparison to β-TCP. The in vitro cytotoxicity was determined by the microculture tetrazolium (MTT) assay. HBDC were grown on the materials for 3, 7, 11, 15 and 19 days and counted. Cell morphology, cell attachment, cell spreading and the cytoskeletal organization of HBDC cultivated on the substrates were investigated using laser scanning microscopy and …environmental scanning electron microscopy. All substrates supported sufficient cellular growth for 19 days and showed no cytotoxicity. On each material an identical cell colonisation of well communicating, polygonal, vital cells with strong focal contacts was verified. HBDC showed numerous well defined stress fibres which give proof of well spread and strongly anchored cells. Porous surfaces encouraged the attachment and spreading of HBDC. Further investigations regarding long term biomaterial/cell interactions in vitro and in vivo are required to confirm the utility of the new biomaterials. Show more

Keywords: Calcium phosphate(s), biocompatility, MTT assay, environmental scanning electron microscopy, confocal laser scanning microscopy

DOI: 10.3233/BME-2012-0678

Citation: Bio-Medical Materials and Engineering, vol. 21, no. 5-6, pp. 307-321, 2011

Authors: López, Alejandro | Hoess, Andreas | Thersleff, Thomas | Ott, Marjam | Engqvist, Håkan | Persson, Cecilia

Article Type: Research Article

Abstract: Some of the current clinical and biomechanical data suggest that vertebroplasty causes the development of adjacent vertebral fractures shortly after augmentation. These findings have been attributed to high injection volumes as well as high Young's moduli of PMMA bone cements compared to that of the osteoporotic cancellous bone. The aim of this study was to evaluate the use of castor oil as a plasticizer for PMMA bone cements. The Young's modulus, yield strength, maximum polymerization temperature, doughing time, setting time and the complex viscosity curves during curing, were determined. The cytotoxicity of the materials extracts was assessed on cells of …an osteoblast-like cell line. The addition of up to 12 wt% castor oil decreased yield strength from 88 to 15 MPa, Young's modulus from 1500 to 446 MPa and maximum polymerization temperature from 41.3 to 25.6°C, without affecting the setting time. However, castor oil seemed to interfere with the polymerization reaction, giving a negative effect on cell viability in a worst-case scenario. Show more

Keywords: Bone cement, PMMA, low-modulus, castor oil, cytotoxicity

DOI: 10.3233/BME-2012-0679

Citation: Bio-Medical Materials and Engineering, vol. 21, no. 5-6, pp. 323-332, 2011

Authors: Uemura, Takuya | Takamatsu, Kiyohito | Ikeda, Mikinori | Okada, Mitsuhiro | Kazuki, Kenichi | Ikada, Yoshito | Nakamura, Hiroaki

Article Type: Research Article

Abstract: We previously reported a bioabsorbable nerve conduit coated with Schwann cells for the treatment of peripheral nerve defects. Since there have been dramatic developments in induced pluripotent stem (iPS) cells in recent years, the purpose of the present study was to create a tissue-engineered nerve conduit coated with iPS cell-derived neurospheres. Such a conduit was constructed by three-dimensional (3D)-culture of these cells using a bioabsorbable polymer conduit as a scaffold. The nerve conduit was composed of a mesh of poly L-lactide, and a porous sponge of 50% poly L-lactide and 50% poly ε-caprolactone. The primary and secondary neurospheres (PNS and …SNS, respectively) induced from iPS cells were suspended in individual conduits. The conduits were incubated for 7 or 14 days in vitro and then evaluated using immunohistochemistry. All of the 7- and 14-day differentiated PNS and SNS were observed to have adhered to the inner surface of the conduits and to have migrated into the inner porous sponge. The engrafted cells were positive for anti-Tuj1, -S-100 and -GFAP antibodies, indicating that their pluripotent ability to form neural or glial cells was maintained. These findings indicate the feasibility of creating nerve conduits coated with a 3D-culture of iPS cell-derived neurospheres for the treatment of peripheral nerve defects. Show more

Keywords: Nerve conduits, induced pluripotent stem cells, tissue engineering, peripheral nerve, regenerative medicine

DOI: 10.3233/BME-2012-0680

Citation: Bio-Medical Materials and Engineering, vol. 21, no. 5-6, pp. 333-339, 2011

Authors: Tai, Ching-Lung | Tsai, Siu-Lian | Chang, Yu-Han | Hsieh, Pang-Hsin

Article Type: Research Article

Abstract: Antibiotic-loaded bone cement is widely used to treat musculoskeletal infections. Here we tested whether the curing temperature affected pore size of the cement and antibiotic release. Bone cement containing vancomycin was cured at 3 temperatures (50, 25 and 0°C). The solidified vancomycin-loaded cement was stored for 1-week at 25 and 5°C and then assayed for antibiotic release. We found that a significantly higher proportion of vancomycin was released from cement cured at 0°C versus that cured at 50°C, and that lower storage temperature also increased antibiotic release.

Keywords: Bone cement, temperature, antibiotic, release, porosity

DOI: 10.3233/BME-2012-0681

Citation: Bio-Medical Materials and Engineering, vol. 21, no. 5-6, pp. 341-346, 2011

Authors: Kameyama, Atsushi | Kato, Junji | De Munck, Jan | Hatayama, Hitoshi | Haruyama, Akiko | Yoshinari, Masao | Takase, Yasuaki | Van Meerbeek, Bart | Tsunoda, Masatake

Article Type: Research Article

Abstract: The purpose of this study was to evaluate whether violet-laser diode (VLD) can be used as light-curing source. The ultimate (micro-)tensile strength (μTS) of three adhesives was determined when cured by VLD in comparison with curing by two different types of commercial LED light-curing units. One VLD (VLM 500) and two LED units (Curenos and G-Light Prima) were used to cure the adhesive resin of the two-step self-etch adhesives Clearfil SE Bond, Tokuso Mac Bond II, and FL-Bond II. A 0.6-mm thick acrylic mould was filled with adhesive resin and cured for 60 s. After 24-h water storage, specimens were …trimmed into an hourglass shape with a width of 1.2 mm at the narrowest part, after which the μTS was determined (n=10). In addition, the light transmittance of each adhesive was characterized using a UV-vis-NIR spectrometer. No significant difference in curing efficiency between VLD and LED were observed for both Tokuso Mac Bond II and FL-Bond II (p>0.05). For Clearfil SE Bond, the μTS of VLD-cured specimens was higher than that of the specimens cured by the LED Curenos unit (p<0.05). Spectrometry revealed that this marked difference must be attributed to a different light transmittance of Clearfil SE Bond for visible blue light versus for the lower area of UV and visible violet light. In conclusion, A GaN-based violet laser diode can be used as light-curing source to initiate polymerization of dental resins. Show more

Keywords: Violet laser diode, light-curing unit, dental adhesive, ultimate tensile strength, UV-vis-NIR spectra, photo-initiator

DOI: 10.3233/BME-2012-0682

Citation: Bio-Medical Materials and Engineering, vol. 21, no. 5-6, pp. 347-356, 2011

Article Type: Other

Citation: Bio-Medical Materials and Engineering, vol. 21, no. 5-6, pp. 357-361, 2011

Article Type: Other

Citation: Bio-Medical Materials and Engineering, vol. 21, no. 5-6, pp. 363-364, 2011