Characterization of hydroxyapatite deposition on biomimetic polyphosphazenes by time-of-flight secondary ion mass spectrometry (ToF-SIMS)

Deposition of calcium hydroxyapatite on negatively charged polyphosphazene surfaces

“…This trend continued into week 3, with a general increase in the density of the mineralized material. This is in contrast to previously developed polyphosphazene samples which showed mostly sporadic deposition of calcium phosphate along their surface which resulted in a maximum of 27% mass gain after immersion in SBF for 4 weeks …”

“…By comparing this spectrum with the XRD spectrum of hydroxyapatite, the new signals may be indicative of the 002 and 211/112/300 planes of hydroxyapatite, respectively. The breadth of these peaks is consistent with previously reported examples of HAp deposited on surfaces and may correspond to signal broadening reported for amorphous deposited inorganic phosphates …”

“…Polymer 5a gained a total of 115% mass by week 4, while polymer 3a showed a lower mass gain of 79%. This can be compared to the maximum 15–30 mass % increase in previously developed systems . ESEM and EDS analysis allowed a qualitative identification of the deposited mineral.…”

“…Previous work has shown that polyphosphazenes with biologically compatible side groups are biocompatible, have highly tunable rates of hydrolytic breakdown and are capable of producing a minimal inflammatory response when implanted in vivo . More recently, we have investigated polyphosphazenes containing phosphonic acid functionalized side groups, in an attempt to generate materials capable of nucleating the growth of hydroxyapatite during exposure to SBF . Although these materials were shown to have hydroxyapatite deposits on their surface, the coatings were sparse, with very little HAp deposited during the 4 week trial.…”

Understanding Electrodeposition of Chitosan–Hydroxyapatite Structures for Regeneration of Tubular-Shaped Tissues and Organs

“…The intensity of and CH 4 N + for inner surfaces was equal to 3.7 × 10 −3 and 1.6 × 10 −2 for 0.2 wt./vol.% CH and 6.4 × 10 −3 and 2.7 × 10 −2 for 0.8 wt./vol.% CH, respectively. The positive and negative ions characteristic for the HAp reference material identified in the presented work were (m/z = 40), (m/z = 57), (m/z = 63), and (m/z = 79) [ 25 , 26 ]. The intensity of these ions was high for HAp and low for CH.…”