Bio-Medical Materials and Engineering - Volume 24, issue 4

Authors: Ignjatović, Nenad L. | Ninkov, Petar | Sabetrasekh, Roya | Lyngstadaas, Staale Petter | Uskoković, Dragan P.

Article Type: Research Article

Abstract: Most drug delivery systems as treatment modalities for osteomyelitis have not been evaluated for resistant infections. Tigecycline (TG) is an antimicrobial agent that could be used in the treatment of multi-drug-resistant orthopedic infections. The objective of this in vitro study has been to determine what dosage of TG causes changes in the morphology and number of osteoblasts. We have also investigated whether nanoparticulate tigecycline-loaded calcium-phosphate/poly-DL-lactide-co-glycolide is biocompatible and whether it could release bioactive TG in a controlled manner during the observation time. The cytotoxicity was tested by analyzing the release of lactate dehydrogenase from dead osteoblasts to the medium. Staphylococcus …aureus was used to verify the antibacterial effect of the multifunctional drug delivery system. At concentrations as achieved by local application, TG caused high toxic effect and impaired the normal osteoblastic morphology. The nanoparticulate multifunctional drug delivery system showed good compatibility and antibacterial effect during the observation time and thus appears to be suitable for the treatment of osteomyelitis caused by multi-drug-resistant microbes. Show more

Keywords: Calcium-phosphate, poly-DL-lactide-co-glycolide, multifunctional, nano drug delivery

DOI: 10.3233/BME-140978

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 4, pp. 1647-1658, 2014

Authors: Brennan-Pierce, Ellen P. | MacAskill, Ian | Price, Richard B. | Lee, J. Michael

Article Type: Research Article

Abstract: BACKGROUND: Photo-crosslinking of biomolecules such as collagen and fibrinogen is an emerging area of research interest. The use of a small dental curing light with a non-toxic photosensitizer represents a novel, practical approach to periodontal wound treatment. OBJECTIVE: This study evaluated the effects of riboflavin-sensitized photo-oxidation using a dental curing light on two collagenous biomaterials, as a preliminary step towards developing a medical technology for wound closure/healing. METHODS: A collagenous biomaterial (DBP) and type I collagen gels were treated by this photo-oxidative technique and characterized by hydrothermal isometric tension (HIT) analysis, amino acid analysis, SDS-PAGE, and rheology. …RESULTS: HIT analysis suggested that dental curing light exposure for 300 s with riboflavin produced heavily crosslinked DBP. Dental curing light exposure for 300 s with riboflavin also showed a reduction in lysine concentration of DBP. SDS-PAGE showed that dental curing light exposure for 30 or 300 s with riboflavin resulted in crosslinked collagen gels. Dental curing light exposure for 30 s with riboflavin yielded a collagen gel with the strongest rheological characteristics. CONCLUSIONS: This novel approach to wound treatment has potential for wide adoption and clinical use, particularly because dental curing lights, riboflavin, and collagen biomaterials are all used clinically, but not yet combined together as one technology for broad application. Show more

Keywords: Collagen, crosslink, riboflavin, photo-oxidation, dental curing light

DOI: 10.3233/BME-140979

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 4, pp. 1659-1671, 2014

Authors: Kwon, Hyock-Ju | Lee, Jiwon

Article Type: Research Article

Abstract: A low cost, quasi real-time elastography system, displacement-gradient elastography (DGE), was developed by applying digital image correlation (DIC) method and smoothing algorithm to B-mode ultrasound images. In order to achieve quasi real-time elastogram display, a new fast pattern matching algorithm, decoupled cross-correlation (DCC), was proposed and validated. By applying the DGE to various phantoms, elastograms were generated to identify the lesion with wide variations of stiffness ratio and applied strain. The performance of DGE was qualitatively compared with those from a high-end ultrasound scanner using the elastograms of a commercial elastography breast phantom. DGE was also applied to the ultrasound …images of human breast lesions in various BI-RADS categories. This study suggests that DGE may have comparable performance to conventional elastography in detecting breast cancer, while it can be easily implemented onto conventional ultrasound scanners. Show more

Keywords: Displacement-gradient elastography, elastogram, digital image correlation, breast cancer

DOI: 10.3233/BME-140980

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 4, pp. 1673-1692, 2014

Authors: Kieser, David C. | Kanade, Sumedh | Waddell, Neil J. | Kieser, Jules A. | Theis, Jean-Claude | Swain, Mike V.

Article Type: Research Article

Abstract: BACKGROUND: The need for continued refinement of animal models in orthopaedic studies persists despite decades of research. OBJECTIVE: This study investigates the merits of deer bone in comparison to the more commonly used pig and sheep bone as an animal model for the human femur. METHOD: A morphological and biomechanical comparison of deer, pig and sheep rear femurs to those of the human femur is presented. Morphological parameters measured include bone length, cortical and medullary diaphyseal diameters, cortical thickness, cortical cross-sectional area and bone density along the diaphysis. Biomechanical tests included whole-bone four-point flexure tests to determine the …bending stiffness (N/mm), Young's modulus of bending (GPa), and ultimate strength in bending (MPa). In addition torsional stiffness (Nm/degree) as well as mid-diaphyseal cortical compressive elastic modulus (GPa) and strength (MPa) is investigated. RESULTS: On average, deer bone was found to be the least dissimilar from human femur. However, no single bone type consistently resembled the human femur. CONCLUSION: Deer femora should be considered a suitable animal model for the human femur. Show more

Keywords: Bone, fracture, animal model, biomechanics, morphology, comparison, bending stiffness, torsional stiffness, Young's modulus, ultimate strength

DOI: 10.3233/BME-140981

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 4, pp. 1693-1703, 2014

Authors: Salvo, P. | Henry, O.Y.F. | Dhaenens, K. | Acero Sanchez, J.L. | Gielen, A. | Werne Solnestam, B. | Lundeberg, J. | O'Sullivan, C.K. | Vanfleteren, J.

Article Type: Research Article

Abstract: The request of high specificity and selectivity sensors suitable for mass production is a constant demand in medical research. For applications in point-of-care diagnostics and therapy, there is a high demand for low cost and rapid sensing platforms. This paper describes the fabrication and functionalization of gold electrodes arrays for the detection of deoxyribonucleic acid (DNA) in printed circuit board (PCB) technology. The process can be implemented to produce efficiently a large number of biosensors. We report an electrolytic plating procedure to fabricate low-density gold microarrays on PCB suitable for electrochemical DNA detection in research fields such as cancer diagnostics …or pharmacogenetics, where biosensors are usually targeted to detect a small number of genes. PCB technology allows producing high precision, fast and low cost microelectrodes. The surface of the microarray is functionalized with self-assembled monolayers of mercaptoundodecanoic acid or thiolated DNA. The PCB microarray is tested by cyclic voltammetry in presence of 5 mM of the redox probe K3 Fe(CN6 ) in 0.1 M KCl. The voltammograms prove the correct immobilization of both the alkanethiol systems. The sensor is tested for detecting relevant markers for breast cancer. Results for 5 nM of the target TACSTD1 against the complementary TACSTD1 and non-complementary GRP, MYC, SCGB2A1, SCGB2A2, TOP2A probes show a remarkable detection limit of 0.05 nM and a high specificity. Show more

Keywords: Printed circuit board gold electrodes, electrolytic plating, surface functionalization, thiolated DNA probes, breast cancer markers detection

DOI: 10.3233/BME-140982

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 4, pp. 1705-1714, 2014

Authors: Amri, M.A. | Firdaus, M.A.B. | Fauzi, M.B. | Chowdhury, S.R. | Fadilah, N.R. | Wan Hamirul, W.K. | Reusmaazran, M.Y. | Aminuddin, B.S. | Ruszymah, B.H.I.

Article Type: Research Article

Abstract: Earlier studies in our laboratory demonstrated that collagen extracted from ovine tendon is biocompatible towards human dermal fibroblast. To be able to use this collagen as a scaffold in skin tissue engineering, a mechanically stronger scaffold is required that can withstand manipulation before transplantation. This study was conducted to improve the mechanical strength of this collagen sponge using chemical crosslinkers, and evaluate their effect on physical, chemical and biocompatible properties. Collagen sponge was crosslinked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and glutaraldehyde (GA). Tensile test, FTIR study and mercury porosimetry were used to evaluate mechanical properties, chemical property and porosity, respectively. MTT …assay was performed to evaluate the cytotoxic effect of crosslinked collagen sponge on human dermal fibroblasts. The FTIR study confirmed the successful crosslinking of collagen sponge. Crosslinking with EDC and GA significantly increased the mechanical strength of collagen sponge, with GA being more superior. Crosslinking of collagen sponge significantly reduced the porosity and the effect was predominant in GA-crosslinked collagen sponge. The GA-crosslinked collagen showed significantly lower, 60% cell viability towards human dermal fibroblasts compared to that of EDC-crosslinked collagen, 80% and non-crosslinked collagen, 100%. Although the mechanical strength was better when using GA but the more toxic effect on dermal fibroblast makes EDC a more suitable crosslinker for future skin tissue engineering. Show more

Keywords: Tissue engineering, collagen, crosslinked, human dermal fibroblast

DOI: 10.3233/BME-140983

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 4, pp. 1715-1724, 2014

Authors: Pulat, Mehlika | Özgündüz, Hediye İrem

Article Type: Research Article

Abstract: Semi-interpenetrating polymer network (IPN) hydrogels with different compositions of poly(vinyl alcohol) (PVA), poly(acrylic acid) (PAA) and poly(acrylamide) (PAAm) were synthesized via free radical polymerization using ethylene glycol dimethacrylate (EGDMA) as crosslinker. The variations of swelling percentages (S%) with time, temperature and pH were determined for all hydrogels. Average S% values at pH=7.4 and 37°C were determined to be 1660% for PAA/PVA, the most swollen hydrogel, and 550% for PAAm/PVA, the least swollen IPN-hydrogel. Swelling behaviors based on ionic and non-ionic components were also explained with detailed SEM micrographs of the hydrogels.

Keywords: Hydrogels, acrylic acid, acryl amide, poly(vinyl alcohol), swelling percentage

DOI: 10.3233/BME-140984

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 4, pp. 1725-1733, 2014

Authors: Okamoto, Eiji | Kato, Yoshikuni | Kikuchi, Sakiko | Mitamura, Yoshinori

Article Type: Research Article

Abstract: The electrical property between an electrode and skin or tissue is one of the important issues for communication performance of the transcutaneous communication system (TCS) using a human body as a conductive medium. In this study, we used a simple method to measure interface resistance between the electrode and skin on the surface of the body. The electrode–electrode impedance was measured by a commercially available LCR meter with changes in the distance between two electrodes on an arm of a healthy male subject, and we obtained the tissue resistivity and electrode–skin interface resistance using the cross-sectional area of the …arm. We also measured transmission gain of the TCS on the surface of the body, and we investigated the relationship between electrode–skin interface resistance and transmission gain. We examined four kinds of electrodes: a stainless steel electrode, a titanium electrode, an Ag–AgCl electrode and an Ag–AgCl paste electrode. The stainless steel electrode, which had lower electrode–skin resistance, had higher transmission gain. The results indicate that an electrode that has lower electrode–skin resistance will contribute to improvement of the performance of the TCS and that electrode–skin interface resistance is one of valuable evaluation parameters for selecting an optimum electrode for the TCS. Show more

Keywords: Artificial organs, artificial heart, transcutaneous monitoring, intrabody communication, electrode impedance

DOI: 10.3233/BME-140985

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 4, pp. 1735-1742, 2014

Authors: Chun, Ho Jong | Lee, Hae Giu | Lyoo, Won Seok | Lee, Ji Youl | Kim, Jina

Article Type: Research Article

Abstract: Syndiotactic polyvinyl alcohol (PVA) had been developed to overcome the drawbacks of atactic PVA spheres that deform easily, which can lead to non-target embolization. This study was performed to evaluate the in vivo stability of spherical shape of the syndiotactic PVA spheres. Selective arteriography and transarterial embolization (TAE) were performed in the main renal arteries of eight New Zealand white rabbits using syndiotactic PVA sphere that consisted of syndiotactic PVA skin and a copolymer core of vinyl acetate/vinyl pivalate. The size of the syndiotactic PVA spheres used for the TAE was 212–355 μm. The rabbits were sacrificed 12–14 days after …TAE. Gross and microscopic examinations of each kidney were performed. The microscopic examination showed infarction of all embolized kidneys. Syndiotactic PVA spheres were seen uniformly within the arterial lumen and appeared as round ring-like structures without any deformity. The syndiotactic PVA spheres exclusively occupied the arterial lumen. As a conclusion, syndiotactic PVA spheres maintained their spherical shape without significant deformation in this in vivo short-term experimental study. Further investigation is necessary for evaluation of detailed effects of physical stability in tumor embolization. Show more

Keywords: Therapeutic embolization, polyvinyl alcohol, animal experiments

DOI: 10.3233/BME-140986

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 4, pp. 1743-1750, 2014

Authors: Pazarlioglu, S. Serdar | Gokce, Hasan | Ozyegin, Sevgi | Salman, Serdar

Article Type: Research Article

Abstract: In this study, we obtained hydroxyapatite powders from the femur bones of meleagris gallopova at three steps and sintered at five different temperatures. The reactions, which occur during sintering of obtained powders, have been characterized by X-ray diffraction (XRD) patterns, scanning electron microscope (SEM), differential thermal analysis (DTA), thermo-gravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) techniques. The mechanical properties of meleagris gallopova hydroxyapatite powders were determined by the measurements of density, hardness, porosity, activation energy for grain growth, variation of average grain sizes, fracture toughness and compression strength. The Fourier transform infrared spectra and the thermogravimetric analysis/differential thermal …analysis thermograms of meleagris gallopova hydroxyapatite powders indicated that the presence of organic compounds were completely removed from the matrice. The X-ray diffraction patterns showed that decomposition of meleagris gallopova hydroxyapatite into tricalcium phosphate and calcium oxide was observed for the sintered samples at 1300°C. At the same temperature, formation of microcracks were also detected by scanning electron microscopy image. Mechanical tests showed that maximum hardness, fracture toughness and compression strength values were measured for the sintered samples at 1200°C. Show more

Keywords: Meleagris gallopova, hydroxyapatite, sintering

DOI: 10.3233/BME-140987

Citation: Bio-Medical Materials and Engineering, vol. 24, no. 4, pp. 1751-1769, 2014