Synthesis of chitosan/hydroxyapatite membranes coated with hydroxycarbonate apatite for guided tissue regeneration purposes

Abstract

Chitosan, which is a non-toxic, biodegradable and biocompatible biopolymer, has been widely researched for several applications in the field of biomaterials. Calcium phosphate ceramics stand out among the so-called bioceramics for their absence of local or systemic toxicity, their non-response to foreign bodies or inflammations, and their apparent ability to bond to the host tissue. Hydroxyapatite (HA) is one of the most important bioceramics because it is the main component of the mineral phase of bone. The aim of this work was to produce chitosan membranes coated with hydroxyapatite using the modified biomimetic method. Membranes were synthesized from a solution containing 2% of chitosan in acetic acid (weight/volume) via the solvent evaporation method. Specimens were immersed in a sodium silicate solution and then in a 1.5 SBF (simulated body fluid) solution. The crystallinity of the HA formed over the membranes was correlated to the use of the nucleation agent (the sodium silicate solution itself). Coated membranes were characterized by means of scanning electron microscopy-SEM, X-ray diffraction-XRD, and Fourier transform infrared spectroscopy-FTIR. The results indicate a homogeneous coating covering the entire surface of the membrane and the production of a semi-crystalline hydroxyapatite layer similar to the mineral phase of human bone.

Titanium Coating with Hydroxyapatite and Chitosan Doped with Silver Nitrate

“…This method consists initially in an alkaline treatment, in which the substrate is submerged in a 5M NaOH solution at 60ºC for 24 hours, to produce active sites on the metal surface, in order to favor hydroxyapatite precipitation 5,19 . Subsequently, the substrate was subjected to a heat treatment at 600ºC for one hour and cooled at room temperature, to eliminate the hydrated phase and form a stable layer.…”

“…Titanium and its alloys are prominent for presenting biocompatibility, high resistance to corrosion and a relatively low density, becoming important materials for research in the field of Biomedicine [1][2][3][4][5] . Nevertheless, results confirm that the bioactive materials in the surface of the implant favor osseointegration time.…”

Membranes for periodontal tissues regeneration

“…The coating or incorporation of calcium salts such as calcium silicate [48] or calcium carbonate (CaCO3) [50], or bioactive glass [46,49], have contributed to improve the osteoconductive and osteoinductive properties of GBR membranes. Fraga et al [48] produced a chitosan membrane coated with calcium silicate that showed to induce the formation of a low crystallinity hydroxyapatite layer similar to the human bone in vitro, when immersed in a SBF solution. A chitosan membrane combined with bioactive glass was developed by Mota et al [46].…”

“…Other biomaterials used for tissue engineering purposes have been tested in the development of membranes for GTR applications. Materials such as alginate, chitosan, polycaprolactone or poly (trimethylene carbonate) have been used in recent studies [41][42][43][44][45][46][47][48][49][50].…”

Preparation of Chitosan/Hydroxyapatite Substrates with Controllable Osteoconductivity Tracked by AFM

“…46 To enhance the osteoconductivity of implants, many methods, such as plasma spraying, 8,15 sol-gel process, 45 electrochemical deposition 9 and simulated body fluid (SBF) treatments, 2,11,31,44 have been proposed to produce a calcium phosphate layer on implant surfaces. Compared with the other processes, SBF treatments create a uniform calcium phosphate layer under mild and ecofriendly conditions.…”