Biodegradation and cytotoxicity of ciprofloxacin-loaded hydroxyapatite-polycaprolactone nanocomposite film for sustainable bone implants

Abstract

Introduction: In recent years there has been a steep increase in the number of orthopedic patients for many reasons. One major reason is osteomyelitis, caused by pyrogenic bacteria, with progressive infection of the bone or bone marrow and surrounding tissues. So antibiotics must be introduced during bone implantation to avoid prolonged infection.

Aim: The objective of the study reported here was to prepare a composite film of nanocrystalline hydroxyapatite (HAp) and polycaprolactone (PCL) polymer loaded with ciprofloxacin, a frequently used antibiotic agent for bone infections.

Methods: Nanocrystalline HAp was synthesized by precipitation method using the precursor obtained from eggshell. The nanocomposite film (HAp-PCL-ciprofloxacin) was prepared by solvent evaporation. Drug-release and biodegradation studies were undertaken by immersing the composite film in phosphate-buffered saline solution, while a cytotoxicity test was performed using the fibroblast cell line NIH-3T3 and osteoblast cell line MG-63.

Results: The pure PCL film had quite a low dissolution rate after an initial sharp weight loss, whereas the ciprofloxacin-loaded HAp-PCL nanocomposite film had a large weight loss due to its fast drug release. The composite film had higher water absorption than the pure PCL, and increasing the concentration of the HAp increased the water absorption. The in vitro cell-line study showed a good biocompatibility and bioactivity of the developed nanocomposite film.

Conclusion: The prepared film will act as a sustainable bone implant in addition to controlled drug delivery.

Keywords: antibiotics; cytotoxicity; fibroblast; in vitro; nanocrystalline; osteomyelitis.

Figure 1

Preparation of ciprofloxacin-loaded hydroxyapatite (HAp) and polycaprolactone (PCL) nanocomposite film.

Figure 2

Phase contrast microscopy of morphology of cultured NIH-3T3 cells.

Figure 3

X-ray diffraction pattern of nano hydroxyapatite.

Figure 4

Fourier-transform infrared spectrum of ciprofloxacin loaded hydroxyapatite (HAp)-polycaprolactone (PCL) nanocomposite film.

Figure 5

Fourier-transform infrared spectrum of hydroxyapatite.

Figure 6

Transmission electron microscopy image (A), and energy-dispersive X-ray spectroscopy and SAD (B) of hydroxyapatite. Abbreviations: cts, carpal tunnel syndrome; SAD, selected area diffraction.

Figure 7

Weight loss (A) and water uptake (B) of ciproflaxin-loaded hydroxyapatite (HAp)-polycaprolactone (PCL) nanocomposite and pure PCL film after incubation in phosphate-buffered saline for periods up to 7 days.

Figure 8

Drug-release profile of ciprofloxacin in phosphate-buffered saline (PBS) for prolonged periods at room temperature (RT) and at 37°C.

Figure 9

Phase contrast microscopy of cells attached onto composite film at 24 hours.

Figure 10

Phase contrast microscopy of cells proliferated on composite film at (A) 72 hours and (B) 96 hours.

Figure 11

Phase contrast microscopy of cell viability of NIH-3T3 cells obtained after 96 hours.

Figure 12

MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay differentiation rate of MG-63 cells cultured for 1–5 days on polycaprolactone (PCL) and hydroxyapatite (HAp)-PCL composite film.