Evaluation of Alkaline-Treated Polycaprolactone and Zr-Hydroxyapatite as a Drug Delivery System in Dentistry

Abstract

Objectives: To develop alkaline-treated polycaprolactone (PCL) and Zrhydroxyapatite (Zr-HA) and fabricate their mixtures as drug delivery systems for dental application. Methods: PCL was subjected to hydrolysis by using concentrated NaOH. Zr-HA was synthesized by co-precipitation reaction that contained Ca(NO 3 ) 2 , (NH 4 ) 2 HPO 4 and ZrO 2 at 65 O C. The obtained materials were characterized by using techniques such as X-Ray Fluorescence, Fourier Transform Infrared Spectroscopy, X-Ray Diffraction, or rheometric analysis. Various compositions of the Zr-HA and the modified-PCL were used for preparing drug delivery systems, and properties including cytotoxicity, degradation, and toluidine blue (TB) binding/releasing were investigated. Findings: The synthesized Zr-HA was more non-stoichiometric than HAcontrol. Improved hydrophilicity was evident for the modified-PCL. Drug carriers composing of the Zr-HA and the modified-PCL were increasingly degradable in phosphate buffer saline solution compared to those containing HA/PCL-control, resulting in 9% and 6% weight loss after 8 weeks of the immersion, respectively. Binding of TB on the Zr-HA/the modified-PCL mixture increased while the release of such bound dye decreased in comparison with that of HA/PCL counterpart. All of the developed materials were non-cytotoxic based on MTT assay using L929 cell line. Novelty: Partial inclusion of Zr 4+ ions in Ca 2+ lattices of HA resulted in fairly degradable Zr-HA. Shortening the epsiloncaprolactone units of PCL by strong bases was simple in producing fragmented PCL polymer that exhibited improvement of hydrophilic interaction towards another. Varying the weight ratios of the Zr-HA and the modified-PCL when to prepare drug carriers is possible to acquire optimal binding/releasing profiles of drugs in dental cavities.

Triple-layered scaffold containing cisplatin and curcumin applied for cancerous bone regeneration

“…It was possible that the gathered polarity of the Zr-HA/modified-PCL system was more suitable in holding of curcumin/β-CD complexes than the Zr-HA/PCL scaffold. 11 Improved curcumin's solubility and release were of the results, consisting with a previous study. 5 A time period of 3 days was spent to approach the IC 50 of curcumin towards SK-ES-1 and MCF-7 cells (Figure 4(b)) that was last compared to that used for cisplatin release.…”

“…Possible explanations for this positive outcome were that the polarity of cisplatin was masked by the modified-PCL, and less attachment to the Zr-HA of the masked cisplatin led to drug release improvement, consisting with a previous study. 11 As a result, cisplatin concentration was beyond the drug’s IC 50 towards SK-ES-1 and MCF-7 cells after released by 24 h. In contrast to cisplatin, curcumin is non-polar and hydrophobic. For improving drug release and preventing drug-drug interactions, curcumin was separately loaded into another scaffold layer and β-CD was applied to assist drug entrapment.…”

“…About 10% of weight of the prepared constructs was lost within a 2-month period. 11 Thus, their remaining in loaded areas of osseous tissues after 1 year could be proposed, sufficient for completion of hard tissue repair. 26…”

“…Our research team had used to synthesize and characterize Zr-HA and modified-PCL as reported. 11 Recently, scaffolds were fabricated by mold compression method using these materials and loaded with cisplatin or curcumin. Drug-free scaffolds were evaluated for osteo-conductive and osteo-inductive properties that associated apatite formation, protein adsorption, and alkaline phosphatase (ALP) production.…”