Chitosan/hydroxyapatite (HA)/hydroxypropylmethyl cellulose (HPMC) spongy scaffolds-synthesis and evaluation as potential alveolar bone substitutes

Colloids Surf B Biointerfaces. 2017 Dec 1:160:553-563. doi: 10.1016/j.colsurfb.2017.09.059. Epub 2017 Oct 4.

Abstract

Alveolar bone loss is associated with infections and its augmentation is a pre-requisite for the success of dental implants. In present study, we aim to develop and evaluate novel freeze dried doxycycline loaded chitosan (CS)/hydroxyapatite (HA) spongy scaffolds where hydroxypropylmethyl cellulose (HPMC) was added as a crosslinker. Scaffolds displayed compressive strength of 14MPa/cm3 and 0.34 as elastic response. The interconnected pore diameter was 41-273μm, favorably provided the template supporting cells and transport. An overall 10% degradation was seen after 14day's studies at pH 7.4 in PBS. Doxycycline hyclate, a frequently used drug to counter oral infections, demonstrated an initial burst release (6-8h), followed by a sustain release profile for the remaining 64h. CS/HA/HPMC scaffolds were nontoxic and promoted pre-osteoblast cell viability as seen with live/dead calcein staining after 24h where scaffolds with 10% and 25% HPMC by weight of scaffold had more viable cells. Scaffolds with 10%, 20% and 25% HPMC by weight of scaffold showed efficient cellular adhesion as seen in scanning electron microscopy images (day 8) indicating that pre-osteoblast cells were able to adhere well on the surface and into the porous structure via cytoplasmic extensions. Hoechst 33258 nuclear staining at day 2 and 8 indicated cell proliferation which was further supported byMTT assay at day 2, 4 and 8. Although all scaffolds supported pre-osteoblast cell viability, alkaline phosphatase (ALP) staining demonstrated that upon induction, differentiation was pronounced in case of scaffolds with 10% HMPC scaffolds. Conclusively, these materials having all the required mechanical and biological properties are potential candidates for alveolar bone regeneration.

Keywords: ALP; Alveolar bone; Biodegradable polymers; Chitosan scaffolds; Dental implants.

MeSH terms

  • Algorithms
  • Animals
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacokinetics
  • Anti-Bacterial Agents / pharmacology
  • Biocompatible Materials / chemistry
  • Biocompatible Materials / pharmacology
  • Bone Substitutes / chemistry
  • Bone Substitutes / pharmacology
  • Cell Adhesion / drug effects
  • Cell Line
  • Cell Proliferation / drug effects
  • Chitosan / chemistry*
  • Doxycycline / chemistry
  • Doxycycline / pharmacokinetics
  • Doxycycline / pharmacology
  • Drug Liberation
  • Durapatite / chemistry*
  • Freeze Drying
  • Hypromellose Derivatives / chemistry*
  • Mice
  • Osteoblasts / cytology
  • Osteoblasts / drug effects
  • Tissue Engineering / methods
  • Tissue Scaffolds / chemistry*

Substances

  • Anti-Bacterial Agents
  • Biocompatible Materials
  • Bone Substitutes
  • Hypromellose Derivatives
  • Chitosan
  • Durapatite
  • Doxycycline