Synthesis and evaluation of a collagen–brushite cement as a drug delivery system

Abstract

Calcium phosphate cements are known for their biocompatibility and bioactivity, which has led to a significant increase in their use. They have the advantage of being prepared as a malleable paste that sets in a few minutes and can be easily applied in bone defects. In this research work, 6 brushite cement formulations were prepared and the effect of collagen addition and the release of tetracycline were evaluated. All cements gave a malleable paste that set in 2 or 3 min, resulting in a material with pores of 5–20 μm. The cements showed compression resistance values between 0.8 and 1.7 MPa, and the addition of collagen was the most influential factor in the increase of this property. Up to 40 % of the drug was released after 7 days and the effectiveness of its antimicrobial activity was confirmed.

Effect of the Addition of Alginate and/or Tetracycline on Brushite Cement Properties

“…Table 2 shows the results of the mechanical property (compression strength) evaluation. Values between 1.6 and 2.6 MPa for the compressive strength of the samples were obtained, which corresponds to what is reported in the literature for this type of cement [ 13 , 16 , 21 , 30 ].…”

“…It is also observed that the samples with sodium alginate and without the presence of tetracycline in their formulations (A2T0 and A5T0) were the ones that reached the highest values. As expected, the addition of sodium alginate increases the mechanical properties of the material; this result corresponds with the effect reported in other studies [30].…”

“…Table 2 shows the results of the mechanical property (compression strength) evaluation. Values between 1.6 and 2.6 MPa for the compressive strength of the samples were obtained, which corresponds to what is reported in the literature for this type of cement [13,16,21,30]. It is also observed that the samples with sodium alginate and without the presence of tetracycline in their formulations (A2T0 and A5T0) were the ones that reached the highest values.…”

“…For a second stage, the release no longer depends only on the solubility of the drug, but also on other factors, such as the advance of the release front, the concentration of the drug and the diffusion medium added. In this case, the logistic function that fits the release profile manages to encompass not only the mechanisms of the second stage but also the diffusion mechanisms that govern the first stage, which is why it is able to describe the entire release process [ 10 , 30 , 32 , 33 , 36 ].…”

“…The effectivity of the cements as drug release systems was proven by the inhibition zones, within which there was no bacterial growth in the culture medium. The results of the microbiological study demonstrated that the antibiotic not only is released, but also maintains its pharmacological activity [ 30 , 37 , 38 ].…”