Development of bone screw using novel biodegradable composite orthopedic biomaterial: from material design to in vitro biomechanical and in vivo biocompatibility evaluation

2019 ◽  
Vol 14 (4) ◽  
pp. 045020 ◽  
Author(s):  
Ajay Suryavanshi ◽  
Kunal Khanna ◽  
K R Sindhu ◽  
Jayesh Bellare ◽  
Rohit Srivastava
2006 ◽  
Vol 34 (05) ◽  
pp. 873-886 ◽  
Author(s):  
Chun-Hsu Yao ◽  
Bai-Shuan Liu ◽  
Chau-Guey Liu ◽  
Yueh-Sheng Chen

The purpose of this investigation was to prepare and evaluate the feasibility and biocompatibility of a new composite as a large defect bone substitute. The new GTGG was mainly composed of tricalcium phosphate ceramic particles and glutaraldehyde crosslinked gelatin in which Gui-Lu-Jiao was added (a mixture of Cervi Colla Cornus and Colla Plastri Testudinis). In the in vitro study, rat's calvaria osteoblasts were used to study bone characteristics upon exposure to different concentrations of the Gui-Lu-Jiao solution. In the in vivo study, GTGG composites were implanted into the defects of calvarial bones in mature New Zealand rabbits to test their osteogenerative characteristics. As a result, we found that Gui-Lu-Jiao added to the culture could promote the proliferation of osteoblasts. In addition, GTGG could induce a large amount of new bone growth in the rabbit's calvarial bone defect. Therefore, the GTGG composite might be a potential bone substitute.


1992 ◽  
Vol 166 (1) ◽  
pp. 145-168
Author(s):  
J. J. THOMASON ◽  
A. A. BIEWENER ◽  
J. E. BERTRAM

Surface strains were recorded from four rosette gauges at different sites on the right forehooves of three ponies running on a treadmill at seven constant speeds and using three gaits. Principal strains determined from the rosette signals indicate that the hoof material is loaded predominantly in compression and that the wall is distorted in a regular, repeatable manner at all speeds and gaits. Peak principal strains reach −5000 με, compared with −2800 με reported for the equine radius under similar locomotory conditions. Orientations of peak compressive strains do not correlate strongly with microstructural axes in the material. Comparison of our in vivo strain records with previous in vitro studies of the material properties of the wall shows that hoof keratin behaves as a multidirectional composite, capable of tolerating its usual operating strains in any direction. This mechanical behaviour also allows the material to withstand many unpredictable loading situations when the hoof contacts irregular substrata. An important property of the hoof wall is its ability to resist or redirect cracks. We found that the anterior aspect of the wall is loaded in biaxial compression, which assists in preventing the formation or propagation of cracks and reduces peak strain magnitudes. The strain patterns correlate well with current models of hoof distortion during weightbearing. In these models, transmission of force between the ground and the skeleton is seen as the primary cause of compression in the material. The third phalanx, which transmits the weight, is effectively suspended from the inner surface of the hoof wall. Spreading of the posterior borders (heels) of the hoof also occurs. The combination of weight-bearing, suspension of the third phalanx and heel spreading is probably responsible for the uncommon loading condition of biaxial compression on the anterior wall.


2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Tian Zhang ◽  
Qiang Zheng ◽  
Yike Fu ◽  
Congkun Xie ◽  
Gonglin Fan ◽  
...  

AbstractSonodynamic therapy (SDT), presenting spatial and temporal control of ROS generation triggered by ultrasound field, has attracted considerable attention in tumor treatment. However, its therapeutic efficacy is severely hindered by the intrinsic hypoxia of solid tumor and the lack of smart design in material band structure. Here in study, fine α-Fe2O3 nanoparticles armored with Pt nanocrystals (α-Fe2O3@Pt) was investigated as an alternative SDT agent with ingenious bandgap and structural design. The Schottky barrier, due to its unique heterostructure, suppresses the recombination of sono-induced electrons and holes, enabling superior ROS generation. More importantly, the composite nanoparticles may effectively trigger a reoxygenation phenomenon to supply sufficient content of oxygen, favoring the ROS induction under the hypoxic condition and its extra role played for ultrasound imaging. In consequence, α-Fe2O3@Pt appears to enable effective tumor inhibition with imaging guidance, both in vitro and in vivo. This study has therefore demonstrated a highly potential platform for ultrasound-driven tumor theranostic, which may spark a series of further explorations in therapeutic systems with more rational material design. Graphical Abstract


PLoS ONE ◽  
2013 ◽  
Vol 8 (7) ◽  
pp. e68342 ◽  
Author(s):  
Bao Su ◽  
Xiaohua Peng ◽  
Dianming Jiang ◽  
Jun Wu ◽  
Bo Qiao ◽  
...  
Keyword(s):  

2017 ◽  
Vol 16 (1) ◽  
pp. 36-41
Author(s):  
Anna Morawska-Chochół ◽  
Patrycja Domalik-Pyzik ◽  
Elżbieta Menaszek ◽  
Jacek Sterna ◽  
Wojciech Bielecki ◽  
...  

Background: Commonly, intramedullary nails are made of nondegradable materials, and hence they need to be removed once the bone fracture is healed. We propose a novel composite material consisting of poly-L-lactide matrix modified with carbon and alginate fibers to be used for biodegradable intramedullary fixation. The aim of this study was to make in vitro and in vivo biocompatibility assessments. Methods: In the in vitro conditions, biocompatibility of biomaterials was compared using normal human osteoblasts. After 3 and 7 days, cytotoxicity, viability and proliferation tests were performed, as well as cell morphology and adhesion observations. In the in vivo experiments, Californian rabbits (approx. 9 months old) were used. The composite nails and controls (Kirschner wires) were used for fixation of distal femoral osteotomy. The evaluation was made on the basis of clinical observations, radiographs taken after 2, 4, 6 and 8 weeks post implantation, and macroscopic and histological observations. Results: Cell tests indicated that both modifiers had a positive influence on cell viability. Biodegradable composite nails led to bony union when used for fixation of distal diaphysis osteotomy in rabbits. Histological analysis showed that the initial focal necrosis should be fully compensated for by the osteoblast proliferation and trabeculae formation. Conclusions: Both in vitro and in vivo tests confirmed biocompatibility and potential applicability of novel biodegradable intramedullary nails modified with long carbon and alginate fibers for osteosynthesis of bone epiphysis.


Author(s):  
E. J. Kollar

The differentiation and maintenance of many specialized epithelial structures are dependent on the underlying connective tissue stroma and on an intact basal lamina. These requirements are especially stringent in the development and maintenance of the skin and oral mucosa. The keratinization patterns of thin or thick cornified layers as well as the appearance of specialized functional derivatives such as hair and teeth can be correlated with the specific source of stroma which supports these differentiated expressions.


Author(s):  
M.J. Murphy ◽  
R.R. Price ◽  
J.C. Sloman

The in vitro human tumor cloning assay originally described by Salmon and Hamburger has been applied recently to the investigation of differential anti-tumor drug sensitivities over a broad range of human neoplasms. A major problem in the acceptance of this technique has been the question of the relationship between the cultured cells and the original patient tumor, i.e., whether the colonies that develop derive from the neoplasm or from some other cell type within the initial cell population. A study of the ultrastructural morphology of the cultured cells vs. patient tumor has therefore been undertaken to resolve this question. Direct correlation was assured by division of a common tumor mass at surgical resection, one biopsy being fixed for TEM studies, the second being rapidly transported to the laboratory for culture.


Author(s):  
Raul I. Garcia ◽  
Evelyn A. Flynn ◽  
George Szabo

Skin pigmentation in mammals involves the interaction of epidermal melanocytes and keratinocytes in the structural and functional unit known as the Epidermal Melanin Unit. Melanocytes(M) synthesize melanin within specialized membrane-bound organelles, the melanosome or pigment granule. These are subsequently transferred by way of M dendrites to keratinocytes(K) by a mechanism still to be clearly defined. Three different, though not necessarily mutually exclusive, mechanisms of melanosome transfer have been proposed: cytophagocytosis by K of M dendrite tips containing melanosomes, direct injection of melanosomes into the K cytoplasm through a cell-to-cell pore or communicating channel formed by localized fusion of M and K cell membranes, release of melanosomes into the extracellular space(ECS) by exocytosis followed by K uptake using conventional phagocytosis. Variability in methods of transfer has been noted both in vivo and in vitro and there is evidence in support of each transfer mechanism. We Have previously studied M-K interactions in vitro using time-lapse cinemicrography and in vivo at the ultrastructural level using lanthanum tracer and freeze-fracture.


Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.


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