EFFECT OF COLLAGEN ON THE MORPHOLOGY AND STRUCTURE OF CALCIUM PHOSPHATE NANOPARTICLES

2014 ◽  
Vol 26 (05) ◽  
pp. 1450061
Author(s):  
Hoda Salemi ◽  
Aliasghar Behnamghader ◽  
Mohamadreza Baghaban Eslaminejad ◽  
Mohammad Ataei

Collagen and noncollagenous proteins have an important role in the formation of mineral constituent of bone matrix. In this research, the morphology and phase characteristics of calcium phosphate nanoparticles in presence of collagen were investigated. The synthesis reaction was initiated by mixing H 3 PO 4 as phosphorous source and CaCl 2 as calcium source and type I collagen. Collagen concentration in suspension and Ca to P ratio was 1% and 1.67, respectively. The samples (with collagen and without collagen), were heat treated at 600°C and characterized by X-Ray diffraction (XRD), Fourier transformation infrared (FTIR) and scanning electron microscopy (SEM). More smaller and flake-like shape particles were observed in the SEM images of sample synthesized in the presence of collagen compared to the control sample which was constituted of larger granular particles. The XRD results revealed that the synthesized mineral powders with collagen were composed of hydroxyapatite and octacalcium phosphate. P – O and OH characteristic peaks were identified in FTIR spectra. In hybrid sample, the shift of amides band, revealed the electrostatic interactions between calcium phosphate ions and carboxyl or amino groups of collagen fibrils. The Ca to P molar ratio for sample with collagen was 1.9. It was found that the sample synthesized in the presence of collagen has a similar microstructure to natural bone.

2020 ◽  
Vol 318 (1) ◽  
pp. C111-C124 ◽  
Author(s):  
Paul H. Schlesinger ◽  
Harry C. Blair ◽  
Donna Beer Stolz ◽  
Vladimir Riazanski ◽  
Evan C. Ray ◽  
...  

Bone differs from other connective tissues; it is isolated by a layer of osteoblasts that are connected by tight and gap junctions. This allows bone to create dense lamellar type I collagen, control pH, mineral deposition, and regulate water content forming a compact and strong structure. New woven bone formed after degradation of mineralized cartilage is rapidly degraded and resynthesized to impart structural order for local bone strength. Ossification is regulated by thickness of bone units and by patterning via bone morphogenetic receptors including activin, other bone morphogenetic protein receptors, transforming growth factor-β receptors, all part of a receptor superfamily. This superfamily interacts with receptors for additional signals in bone differentiation. Important features of the osteoblast environment were established using recent tools including osteoblast differentiation in vitro. Osteoblasts deposit matrix protein, over 90% type I collagen, in lamellae with orientation alternating parallel or orthogonal to the main stress axis of the bone. Into this organic matrix, mineral is deposited as hydroxyapatite. Mineral matrix matures from amorphous to crystalline hydroxyapatite. This process includes at least two-phase changes of the calcium–phosphate mineral as well as intermediates involving tropocollagen fibrils to form the bone composite. Beginning with initiation of mineral deposition, there is uncertainty regarding cardinal processes, but the driving force is not merely exceeding the calcium-phosphate solubility product. It occurs behind a epithelial-like layer of osteoblasts, which generate phosphate and remove protons liberated during calcium-phosphate salt deposition. The forming bone matrix is discontinuous from the general extracellular fluid. Required adjustment of ionic concentrations and water removal from bone matrix are important details remaining to be addressed.


2018 ◽  
Vol 69 (7) ◽  
pp. 1706-1709
Author(s):  
Nicoleta Dumitru ◽  
Andra Cocolos ◽  
Andra Caragheorgheopol ◽  
Constantin Dumitrache ◽  
Ovidiu Gabriel Bratu ◽  
...  

There is an increased interest and more studies highlight the fact that bone strength depends not only on bone tissue quantity, but also on its quality, which is characterized by the geometry and shape of bones, trabecular bone microarchitecture, mineral content, organic matrix and bone turnover. Fibrillar type I collagen is the major organic component of bone matrix, providing form and a stable template for mineralization. The biomedical importance of collagen as a biomaterial for medical and cosmetic purposes and the improvement of the molecular, cellular biology and analytical technologies, led to increasing interest in establishing the structure of this protein and in setting of the relationships between sequence, structure, and function. Bone collagen crosslinking chemistry and its molecular packing structure are considered to be distinct features. This unique post-translational modifications provide to the fibrillar collagen matrices properties such as tensile strength and viscoelasticity. Understanding the complex structure of bone type I collagen as well as the dynamic nature of bone tissues will help to manage new therapeutic approaches to bone diseases.


1996 ◽  
Vol 75 (6) ◽  
pp. 811-823 ◽  
Author(s):  
Yusuke Higashi ◽  
Asako Takenaka ◽  
Shin-Ichiro Takahashi ◽  
Tadashi Noguchi

It has been reported that loss of ovarian oestrogen after menopause or by ovariectomy causes osteoporosis. In order to elucidate the effect of dietary protein restriction on bone metabolism after ovariectomy, we fed ovariectomized young female rats on a casein-based diet (50g/kg diet (protein restriction) or 200g/kg diet (control)) for 3 weeks and measured mRNA contents of bone-matrix proteins such as osteocalcin, osteopontin and α1 type I collagen, insulin-like growth factors (IGF) and IGF-binding proteins (IGFBP) in femur. Ovariectomy decreased the weight of fat-free dry bone and increased urinary excretion of pyridinium cross-links significantly, although dietary protein restriction did not affect them. Neither ovariectomy nor protein restriction affected the content of mRNA of osteopontin and osteocalcin; however, ovariectomy increased and protein restriction extensively decreased the α1 type I collagen mRNA content in bone tissues. Ovariectomy increased IGF-I mRNA only in the rats fed on the control diet. Conversely, protein rest riction increased and ovariectomy decreased the IGF-II mRNA content in femur. Furthermore, the contents of IGFBP-2, IGFBP-4 and IGFBP-5 mRNA increased, but the content of IGFBP-3 mRNA decreased in femur of the rats fed on the protein-restricted diet. In particular, ovariectomy decreased the IGFBP-2 mRNA content in the protein-restricted rats and the IGFBP-6 mRNA content in the rats fed on the control diet. These results clearly show that the mRNA for some of the proteins which have been shown to be involved in bone formation are regulated by both quantity of dietary proteins and ovarian hormones.


1982 ◽  
Vol 92 (1) ◽  
pp. 227-230 ◽  
Author(s):  
J D Malone ◽  
S L Teitelbaum ◽  
G L Griffin ◽  
R M Senior ◽  
A J Kahn

The osteoclast, the multinucleated giant cell of bone, is derived from circulating blood cells, most likely monocytes. Evidence has accrued that is consistent with the hypothesis that the recruitment of monocytes for osteoclast development occurs by chemotaxis. In the present study, we have examined the chemotactic response of human peripheral blood monocytes and related polymorphonuclear leucocytes to three constituents of bone matrix: peptides from Type I collagen, alpha 2-HS glycoprotein, and osteocalcin (bone gla protein). The latter two substances are among the major noncollagenous proteins of bone and are uniquely associated with calcified connective tissue. In chemotaxis assays using modified Boyden chambers, Type I collagen peptides, alpha 2HS glycoprotein, and osteocalcin evoke a dose-dependent chemotactic response in human monocytes. No chemotaxis is observed on PMNs despite their ontogenetic relationship to monocytes and their documented sensitivity to a broad range of other chemical substances. Our observations are consistent with the view that osteoclast precursors (monocytes) are mobilized by chemotaxis, and suggest that the chemoattractants responsible for this activity are derived from the bone matrix or, in the case of collagen and osteocalcin; directly from the osteoblasts which produce them.


MRS Bulletin ◽  
1996 ◽  
Vol 21 (11) ◽  
pp. 36-39 ◽  
Author(s):  
Ugo Ripamonti ◽  
Nicolaas Duneas

Recent advances in materials science and biotechnology have given birth to the new and exciting field of tissue engineering, in which the two normally disparate fields are merging into a profitable matrimony. In particular the use of biomaterials capable of initiating new bone formation via a process called osteoinduction is leading to quantum leaps for the tissue engineering of bone.The classic work of Marshall R. Urist and A. Hari Reddi opened the field of osteoinductive biomaterials. Urist discovered that, upon implantation of devitalized, demineralized bone matrix in the muscle of experimental animals, new bone formation occurs within two weeks, a phenomenon he described as bone formation by induction. The tissue response elicited by implantation of demineralized bone matrix in muscle or under the skin includes activation and migration of undifferentiated mesenchymal cells by chemotaxis, anchoragedependent cell attachment to the matrix, mitosis and proliferation of mesenchymal cells, differentiation of cartilage, mineralization of the cartilage, vascular invasion of the cartilage, differentiation of osteoblasts and deposition of bone matrix, and finally mineralization of bone and differentiation of marrow in the newly developed ossicle.The osteoinductive ability of the extracellular matrix of bone is abolished by the dissociative extraction of the demineralized matrix, but is recovered when the extracted component, itself inactive, is reconstituted with the inactive residue—mainly insoluble collagenous bone matrix. This important experiment showed that the osteoinductive signal resides in the solubilized component but needs to be reconstituted with an appropriate carrier to restore the osteoinductive activity. In this case, the carrier is the insoluble collagenous bone matrix—mainly crosslinked type I collagen.


2011 ◽  
Vol 284-286 ◽  
pp. 1794-1799 ◽  
Author(s):  
Yu Lu Wang ◽  
Xue Pin Liao ◽  
Bi Shi

Type I collagen was isolated from calf skin and its assembly on PVA film induced by glutaraldehyde vapor was investigated. It was found that the collagen molecules were firstly orientationally assembled into collagen fibers under the inducement of glutaraldehyde vapor. Then the collagen fibers could be further aggregated into novel network structure in proper conditions of the induced reaction. The morphology of the assembled collagen fibers was depended on induced time and concentration of collagen. The network arrangement could be obtained after being induced for 72h when collagen concentration was 2.5mg/ml. At higher concentration of collagen (5 mg/ml), the collagen fibers with larger dimension were obtained, but the growth of fibers was almost in one direction.


2020 ◽  
Vol 115 (11) ◽  
pp. 399-408
Author(s):  
Catherine Maidment ◽  
Meekyung Ahn ◽  
Rafea Naffa ◽  
Trevor Loo ◽  
Gillian Norris

Looseness is a defect found in leather that reduces its quality by causing a wrinkly appearance in the finished product, resulting in a reduction in its value. Earlier studies on loose leather using microscopy and Raman spectroscopy reported a change in the collagen structure of loose leather. In this study, proteomics was used to investigate the possible molecular causes of looseness in the raw material, the first time such a study has been carried out. Proteins extracted from two regions of raw hide using two different methods were analysed; those taken from the distal axilla, an area prone to looseness, and those taken from the backbone which is less prone to looseness. Analyses using 1DE-LC-MS/MS showed that although the overall collagen concentration was similar in both areas of the hide, the distribution of the different types of collagen differed.  Specifically, concentrations of type I collagen, and the collagen-associated proteoglycan decorin were lower in samples taken from the distal axilla, symptomatic of a collagen network with excess space seen for these samples using confocal microscopy. This study suggests a possible link between the molecular components of raw cattle hide and looseness and more importantly between the molecular components of skin and skin defects. There is therefore potential to develop biomarkers for looseness which will enable early preventative action.


2016 ◽  
Vol 10 (2) ◽  
pp. 12-19
Author(s):  
Sahar S. Karieb ◽  
Mohammed M. Jawad ◽  
Hanady S. Al-Shmgani ◽  
Zahraa H.M. Kadri

Multiple studies have been reported the stimulatory effect of the combinations of nutrients factors on bone formation. One such factor is vitamin K2 which can be associated with bone protective activities. The effect of vitamin K2 alone and in combination with genistein, coumestrol and daidzein on osteoblast differentiation and mineralization were tested. Significantly, vitamin K2 increased bone mineralization in combination with genistein (10-5M), coumestrol (10-7M) and daidzein (10-5M). However, there is no additive effect of this vitamin on alkaline phosphatase (ALP) levels in osteoblasts. By contrast, vitamin K2 enhanced the stimulatory effect of type I collagen and osteocalcin expression. Vitamin K2 alone increased RUNX and OSX expression while there is no synergistic effect with tested compound; this vitamin also did not modulate nuclear factor kappa B ligand (RANKL)/ osteoprotegerin (OPG) ratio expression. These results suggested that vitamin K2 can be more effective factor in the presence of phytoestrogens on the improvement of bone formation after menopause.


Sign in / Sign up

Export Citation Format

Share Document