scholarly journals Long-term water sorption and solubility of experimental bioactive composites based on amorphous calcium phosphate and bioactive glass

2019 ◽  
Vol 38 (4) ◽  
pp. 555-564 ◽  
Author(s):  
Matej PAR ◽  
Nika SPANOVIC ◽  
Ruza BJELOVUCIC ◽  
Danijela MAROVIC ◽  
Gottfried SCHMALZ ◽  
...  
2005 ◽  
Vol 873 ◽  
Author(s):  
Balasundaram G ◽  
Sato M ◽  
Webster TJ

AbstractIn an effort to decrease the number of problems associated with osteoporosis, the long-term goal of the present study is to design calcium phosphate-based nanoparticles that specifically attach to areas of low bone density and once attached, allow for the targeted release of bioactive agents that can quickly increase bone formation. Efforts are focused on nanoparticles of calcium phosphate-based materials since they are similar in size and chemistry to the major inorganic components of bone. As a first step in this research, the objective of the present study was to synthesize nanoparticles of crystalline hydroxyapatite (or HA) and amorphous calcium phosphate. Crystalline HA is stable under physiological fluids and, thus, will release embedded bioactive agents slowly. Alternatively, amorphous calcium phosphate is highly biodegradable and will, thus, release embedded bioactive agents quickly. A further objective of the present study was to functionalize such inorganic biodegradable materials with amino groups which would allow for the subsequent attachment of entities to direct such nanoparticles to osteoporotic bone and increased bone formation once attached. One promising approach to direct the nanoparticles to osteoporotic bone is to attach antibodies to pentosidine on the nanoparticles since pentosidine is present in higher amounts in osteoporotic compared to healthy bone. A promising approach to increase bone growth once nanoparticles attach to osteoporotic bone, is to embed nanoparticles with regions of the bone growth factor: bone morphogenic protein-2 (or BMP-2). Results of this study demonstrated the successful synthesis of both crystalline HA and amorphous calcium phosphate nanoparticles. Furthermore, results showed that these nanoparticles can be functionalized with versatile amino groups. In this manner, this study takes the first steps toward utilizing calcium phosphate based nanoparticles to reverse bone loss associated with osteoporosis.


2016 ◽  
Vol 13 (4) ◽  
pp. 297 ◽  
Author(s):  
UdayaKumar Palaniswamy ◽  
Neha Prashar ◽  
Mamta Kaushik ◽  
SurenderRam Lakkam ◽  
Shikha Arya ◽  
...  

2019 ◽  
Vol 829 ◽  
pp. 16-20
Author(s):  
Nobuhiro Kato ◽  
Mizuki Hirai ◽  
Ei Yamamoto ◽  
Shigeki Hontsu

Dental materials purely composed of calcium phosphate are ideal for the dental medicine. We have been developing ultrathin amorphous calcium phosphate (ACP) sheets for enamel repair. In this study, long term stability of the ultrathin ACP sheets applied on enamel surfaces which kept in a simulated intraoral condition for 21 days was evaluated. Surface morphologies of the ACP sheets were observed by optical images. A boundary condition between the ACP sheet and the enamel was evaluated by cross-sectional SEM image. A durability of the ACP sheet was evaluated by a brushing test conducted after 21 days incubation. As the result of these evaluations, it was confirmed that the ACP sheets were stable even after long-term incubation under the simulated intraoral environment condition.


2012 ◽  
Vol 100B (5) ◽  
pp. 1264-1273 ◽  
Author(s):  
Jennifer L. Moreau ◽  
Michael D. Weir ◽  
Anthony A. Giuseppetti ◽  
Laurence C. Chow ◽  
Joseph M. Antonucci ◽  
...  

Author(s):  
I. E. Glazov ◽  
V. K. Krut’ko ◽  
R. A. Vlasov ◽  
O. N. Musskaya ◽  
A. I. Kulak

Nanocomposites based on apatitic tricalcium phosphate in an autofibrin matrix were obtained by precipitation at a Ca/P ratio of 1.50, pH 9 and a maturation time from 30 min to 7–14 days. The resorbability of nanocomposites was determined by the composition of calcium phosphates, which, during long-term maturation, formed as the calcium-deficient hydroxyapatite with a Ca/P ratio of 1.66, whereas biopolymer matrix favored the formation of more soluble calcium phosphates with a Ca/P ratio of 1.53–1.59. It was found that the fibrin clot stabilized, along with apatitic tricalcium phosphate, the phase of amorphous calcium phosphate, which after 800 °C was transformed into resorbable α-tricalcium phosphate. Citrated plasma inhibited the conversion of apatitic tricalcium phosphate into stoichiometric hydroxyapatite, which also facilitated the formation of resorbable β-tricalcium phosphate after 800 °C. The combined effect of the maturation time and the biopolymer matrix determined the composition, physicochemical and morphological properties of nanocomposites and the possibililty to control its extent of resorption


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Gaoke Feng ◽  
Thanh Dinh Nguyen ◽  
Xin Yi ◽  
Yongnan Lyu ◽  
Zhiyuan Lan ◽  
...  

Objectives. Our previous studies have confirmed the superior biocompatibility of the poly-L-lactic acid/amorphous calcium phosphate (PLLA/ACP) scaffolds compared to PLLA scaffolds at 1-month. In the present study, the long-term inflammatory responses of PLLA/ACP scaffolds in a porcine coronary model have been explored. Methods. The 24 PLLA scaffolds and 24 PLLA/ACP scaffolds were implanted into the coronary arteries of 24 miniature pigs. Serum levels of ALT, AST, and CRP were measured before operation, as well as 1-month, 6-months, 12-months, and 24-months. The vascular segments were taken for pathomorphological observation. HE staining was used for the inflammatory score and fibrosis score. Immunohistochemical staining detected positive expression indexes of MMP-9 and NF-κB. The expression of inflammation-related proteins of IL-1 and IL-6 was detected by Western Blot in surrounding tissues of scaffolds. Results. There was no significant difference between the two groups in ALT, AST, and UR at different time points (P<0.05). The inflammation score in the PLLA/ACP group was lower than that in the PLLA group at 6-months, 12-months, and 24-months (P<0.05), and the fibrosis score was reduced in the PLLA/ACP group than that in the PLLA group at 12-months and 24-months (P<0.05). The expression of MMP-9 and NF-κB in the PLLA/ACP group was significantly less than that in the PLLA group at 6-months, 12-months, and 24-months (P<0.05). The protein expression of IL-1 in the PLLA/ACP group was decreased than that in the PLLA group at 12-months and 24-months (P<0.05). Furthermore, the protein expression of IL-1 was significantly lower than that in the PLLA group at 6-months, 12-months, and 24-months (P<0.01). Conclusions. The supplement of ACP nanoparticles can effectively reduce the long-term inflammatory reaction caused by PLLA and has good safety and biocompatibility. The novel bioabsorbable PLLA/ACP scaffold provides reliable guidance for the development and clinical application of bioabsorbable scaffolds in the future.


Sign in / Sign up

Export Citation Format

Share Document