Composite Based on Biphasic Calcium Phosphate (HA/β-TCP) and Nanocellulose from the Açaí Tegument.

Rachel Valentim,Izael Dos Santos,Carmen Dias,Aline Santos,Marcos Dos Reis,Maria Dos Santos,Victor Pereira,Sabina Andrade

doi:10.3390/ma11112213

Abstract

The use of lignocellulosic remnants of the açaí agro-business will benefit the environment with a precursor material for biomedical applications. Nanocellulose (NC) allows the biomimetic growth of biphasic ceramics on its surface, with characteristics compatible with bone tissue, including bioactive properties and biocompatibility. In this study, the composites were obtained from açaí tegument (Euterpe Oleracea Mart.) NC using acid hydrolysis. The characterization performed by scanning electron microscopy showed the characteristic crystals of hydroxyapatite (HA) and calcium triphosphate (β-TCP) based on the results of X-ray diffraction, with the peak at 22°, showing the NC nucleation of HA and peak at 17° showing tricalcium phosphate (β-TCP). Fourier transform infrared spectroscopy confirmed the presence of O-H at 3400 cm−1 and C-H at 2900 cm−1, which is characteristic of cellulose; peaks were also observed at 1609 cm−1, verifying the reduction in lignin content. Groups PO4−3 at approximately 1070 cm−1, P-OH at 910–1040 cm−1, and HCO3− at 2450 cm−1 confirmed the formation of HA and β-TCP. The zeta potential had a range of −11 ± 23.8 mV related to particle size, which had a range of 164.2 × 10−9–4748 × 10−9 m.

Highlights

Calcium phosphates are ceramic compounds with biomedical applications as their constituents are involved in the formation of bones and teeth, and they have excellent biocompatibility, bioactivity, no toxicity, variable degradation rates, and osteoconductivity [1]
Among the various types of calcium phosphate, hydroxyapatite (HA) and tricalcium phosphate (β-TCP) stand out. Their combinations are called biphasic calcium phosphate ceramics and they make it possible to obtain a composite with improved properties
Due to its calcium phosphate composition equivalent to bone tissue [2], it has been used in bone repair and filling [3,4,5,6], applied as a filling to assist in the regenerative effect [7], and used in various other applications, such as biomedical composites [8,9]

Summary

Introduction

Calcium phosphates are ceramic compounds with biomedical applications as their constituents are involved in the formation of bones and teeth, and they have excellent biocompatibility, bioactivity, no toxicity, variable degradation rates, and osteoconductivity [1]. Among the various types of calcium phosphate, hydroxyapatite (HA) and tricalcium phosphate (β-TCP) stand out. Their combinations are called biphasic calcium phosphate ceramics and they make it possible to obtain a composite with improved properties. Materials 2018, 11, x22F1O3R PEER REVIEW bovine, chickens, and goat bones [12]. It can be obtained through biomimetic growth using sbuogvainrcea,ncehbicakgeansss,eapnudlpg[o1a3t],bwonheicsh[1co2]n.taIitncsainonaslstohabtearoebitmaipnoedrtatnhtrofourgihtsbfioormmiamtieotnic. CCeelllluulloossee iiss aa ppoollyymmeerr ooff vveeggeettaabbllee oorriiggiinn,, aanndd iitt hhaass aaddvvaannttaaggeeoouuss pprrooppeerrttiieess ssuucchh aass ggoooodd mmeecchhaanniiccaall ssttrreennggtthh,,wwhhicichhmmakaekeit iat daedsiersaibrlaebsleousrocuerfcoer fboior mbiaotmeraiatleriniaal sinusatasiunastbalien, aebcolen,oemcoicnso-bmaiscesdbfuatsuedrefu[2t0u]r.e [T2h0e].

Experimental

Results and Discussion

Conclusions